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173 results on '"Abdulhamid M"'

1. Surgical site infections prevalence among caesarean section patients

Author

Tasneem Alkout, Abdulhamid M. Alkout, Esraa Rasheed, Osama Etekbali, Fathi Abousnina, and Alhadi Araibi

Subjects
surgical site infections, caesarean section, antibiotic resistance, Medicine (General), R5-920
Abstract

Introduction: Cesarean section is one of the most prevalent surgical procedures in the world and Surgical Site Infections (SSI) are the most common complication following Cesarean section. This leads to greater patient dissatisfaction, longer hospital stays, and higher treatment costs. The aim of this retrospective study is to determine the prevalence of wound infection and the prevalence of bacterial isolates in post-Cesarean section and its sensitivity to variant antibiotics. Material and methods: Samples were collected from patients who had developed wound infection following cesarean section and cultured on blood, chocolate and chromatic agar. The isolated bacteria was identified by ordinary microbiology techniques. Results: Among 4,482 Cesarean section patients in Albaraa Hospital, the surgical site infections (SSI) rate was 2.94 %. Microorganisms isolated from these cases included Candida albicans at a rate of 0.11%. The remaining 2.83% were bacterial isolates, with 70.1% being gram-positive bacteria significantly higher than the 29.9% attributed to gram-negative bacteria (P = 0.01). The main bacteria isolates were Staphylococcus aureus (37.8%), Staphylococcus epidermidis (23.6%), Pseudomonas aeruginosa (11.4%), Klebsiella pneumonia (8.3%), Escherichia coli (5.3%) and Alpha hemolytic Streptococcus (3.8%) Conclusions: The SSI rate in this study was at the lower limit of the WHO predicted infection rate and the bacterial isolates were sensitive to many antibiotics. This result may be due to the pre, intra and postoperative prophylactic antibiotics administered to patients and other factors such as short hospital stay and staff training in aseptic techniques. This study recommends further assessment of SSI in alternative surgical procedures, and assess the efficiency of prophylactic antibiotics in alternative surgeries in Libya.

Published
2024
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2. Evaluation of the efficacy of stem cell therapy in erectile dysfunction after radical prostatectomy: a comprehensive systematic review

Author

Saad Thamer Alshahrani, Omar Safar, Nazal A Almsaoud, Adel Elatreisy, Ahmed Ibrahim, Sulaiman M Alkhaldi, Abdulhamid M Alkhaldi, Raed Alwadai, Muath Almurayyi, Saeed A Asiri, Abdulaziz M Alqahtani, Abdullah Saleh Alshafi, Saleh Alghamdi, Ahmed Al-Hadi, Basel Hakami, and Meshari A. Alzahrani

Subjects
post-prostatectomy, erectile dysfunction, stem-cell therapy, Medicine (General), R5-920
Abstract

Around 68% patients undergoing radical prostatectomy face postoperative erectile dysfunction. This systematic review aims to investigate the studies pertaining to efficacy of stem cell therapy in alleviating erectile dysfunction (ED) of radical prostatectomy (RP) patients. Furthermore, it provides evidence-based potential benefits of stem cell therapy in addressing erectile dysfunction of those patients. A systematic literature search from PubMed, Google Scholar, Science Direct and clinicaltrial.gov databases was conducted for the clinical trials evaluating efficacy and safety of stem cell therapy in post-prostatectomy erectile dysfunction. The inclusion criteria pertained to the studies reporting pre- and post-outcome erectile function and safety results. Cochrane Robins I was employed for the quality and bias risk. Four studies were finally included. The studies were of high quality as revealed from the quality assessment results. They were the non-randomized human-based clinical trials. Patients follow-up ranged from 3 to 12 months. Intercourse satisfaction scores were improved after 6 and 12 months of stem cell therapy. No serious adversities were reported during and after the study period. It was thus a safe therapeutic option as per these results. This study evaluated the role of stem cell therapy in post-RP ED. The included studies depicted its efficacy and safety. The information on stem cell therapy for ED was limited, however it could provide foundation for future research. Large-scale human studies with robust research designs would bring more objectivity and conclusive evidence.

Published
2024
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3. Platelet Count as Useful Indicator for Gram-Type of Bacteria Causing Urinary Tract Infection in Women

Author

Abdulaziz Dwaya, Abdurrazag Urayet, Mohamed B. Milad, and Abdulhamid M. Alkout

Subjects
urinary tract infection, women, platelet count, bacteria, gram-type, Medicine (General), R5-920
Abstract

Introduction: Urinary Tract infection (UTI) is considered as the most common infections disease among women. UTI may lead to a serious complication in both kidneys. In this study, we tried to determine whether the alternation in platelet count during UTI is related to specific Gram-type of bacteria causing the infection. This assists the medical staff in selection of suitable antimicrobial drug. Material and Methods: Data of all urine cultures from Gynecology Department/ Albaraa Hospital/Tripoli processed at the Laboratory during a period of three years (2017 - 2019). All Data analysis and statistics were made with the SPSS software version 16 and performed with one-way ANOVA and a parametric test was used for categorical values and not normally distributed values. Results: A growth was detected in 101 of 193 (52%) samples and 22 (11%) were mixed growth. Gram-negative bacteria identified in 57% (45/79) while 43% (34/79) occurred with Gram-positive bacteria. Regarding to platelets count alteration, it is revealed that there was a significant difference between cases infected by Gram-negative bacteria compared to others infected by Gram-positive bacteria and control group. Conclusions: Results of the current study suggest that the change in platelet count during UTI is associated with causative bacteria’s Gram-type.

Published
2021
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4. The impact and effectiveness of new coronavirus vaccine on disease outcome worldwide

Author

Tasneem A. Alkout and Abdulhamid M. Alkout

Subjects
full vaccine, total vaccine, covid-19, sars-cov-2, mrna vaccine, vector vaccine, inactivated virus vaccine, Medicine (General), R5-920
Abstract

Introduction: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is spreading rapidly around the world caused serious respiratory disease leading to death, therefore vaccine is the effective way to control this pandemic. Scientists tried to produce safe and effective SARS-CoV-2 vaccines in record time and vaccination program started in December 2020. The aim of this study to determine the impact of SARS-CoV-2 vaccine on COVID-19 disease. Materials and methods: The COVID-19 cases data of post-vaccination and pre-vaccination were collected from Worldmeter website, and the percentage of vaccinated people data obtained from Statistics and Research Coronavirus Vaccinations. The statistical analyses performed with SPSS software version 16.0. Results: The results showed countries with higher percentage of full dose vaccinated people correlated strongly with decrease of death and the severity of the disease among their infected population. This study showed that different vaccine mechanism against SARS-CoV-2 virus of more than 23.5% of vaccination people with full dose vaccine is effective to decrease death and serious symptoms of COVID-19 disease and increasing the recovery rate. Conclusions: Different mechanism type of full dose vaccine against SARS-CoV-2 is effective to decrease death and serious symptoms of COVID-19 disease with increasing recovery rate. It was difficult to assess the effect of single dose alone, therefore more studies are recommended to assess the effect of single dose vaccine with COVID-19 disease outcome and to determine if the vaccine will accelerate the period of recovery rate and reduce the infectious period time in each country.

Published
2021
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5. ABO blood groups among Coronavirus disease 2019 patients

Author

Tasneem A. Alkout and Abdulhamid M. Alkout

Subjects
abo blood group, covid-19, sars-cov-2, Medicine (General), R5-920
Abstract

Introduction: Susceptibility to some infectious diseases has been associated with blood group phenotypes. Coronavirus disease 2019 (COVID-19) is a new infectious disease caused by a novel corona virus designated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) which has spread rapidly around the world. The objective of this study was to determine if the susceptibility or severity to COVID-19 was associated with ABO blood group distribution among the affected countries. Materials and methods: This retrospective study of COVID-19 disease was based on data from 105 countries collected on the 13th of April 2020 and analysed by SPSS software version 16.0. Spearman correlation coefficient and Kruskal Wallis test were used to assess for associations between ABO blood group with COVID-19. Results: The results indicated that individuals of blood group A are at increased risk of infection by SARS-CoV-2 virus and severity of COVID-19 disease. Blood groups B and O were less likely to be infected and the disease evolves less severe. Conclusions: The results are discussed in relation to the host-parasite interactions that might contribute to susceptibility to these infections.

Published
2020
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6. Benchmarking the Non-flow Contributions to the Elliptic Flow Parameter ($v_{_2}$) in Proton-Proton Collisions

Author

Abdulhamid, M. I., Hamed, A. M., Osama, E. A., Rateb, M., Sadoun, N. K., and Sawy, F. H.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment
Abstract

This manuscript reports on the elliptic flow parameter, $v_{_2}$, in proton-proton (p-p) collisions using PYTHIA8 event generator simulations. The typical Event Plane ($EP$) method $v_{_2}$($EP$) as the one used for the real data analysis has been adopted to measure the $v_{_2}$ of particles composed of different quark flavors, and produced at mid-pseudorapidity $|\eta| \le 1$ at center-of-mass energy $\sqrt{s}$ = 200 GeV and $\sqrt{s}$ = 13 TeV. The event plane has been constructed using the soft charged particles with transverse momentum ($p{_{_T}} < $ 2 GeV/c) produced in various $\eta$ ranges. The pseudorapidity gap technique ($\Delta\eta$) between the particle of interest and the soft charged particles contributed to the event plane constructions has been utilized to benchmark the non-flow contributions. The $v_{_2}^{\pi^{^\pm,}\pi^{^0}}$, $v_{_2}^{J/\psi,\Upsilon, K, D, B}$, and the $v_{_2}^{\gamma_{dir}}$ show similar pattern dependence on the transverse momentum for the same $\Delta\eta$, at both $\sqrt{s}$ = 200 GeV and $\sqrt{s}$ = 13 TeV. At each center-of-mass energy, the measured $v_{_2}$ shows obvious dependence on the quark flavor contents where $v_{_2}^{\gamma_{dir}}$ $\le$ $v_{_2}^{J/\psi, \Upsilon, K, D, B}$ $\le$ $v_{_2}^{\pi^{^\pm,}\pi^{^0}}$ for similar $\Delta\eta$ gap. The measured $v_{_2}$ shows slightly higher values at smaller $\sqrt{s}$ for particles of similar values of $\Delta\eta$ gaps, particularly at small $\Delta\eta$ gap. The measured $v_{_2}$ for all particles shows systematic decreases with increasing the $\Delta\eta$ gap as expected from the previous experimental results. Because PYTHIA8 simulations do not incorporate final state interactions, the $v_{_2}(EP)$ values reported here primarily reflect the non-flow contributions and its dependence on the quark contents, pseudorapidity gap as a function on $p_{T}$ at each center of mass-energy., Comment: 14 pages, 5 figures

Published
2024

7. Correlations of event activity with hard and soft processes in $p$ + Au collisions at $\sqrt{s_\mathrm{NN}}$ = 200 GeV at STAR

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kołaś, J., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matonoha, O., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pal, S., Pandav, A., Panday, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T. L., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

With the STAR experiment at the BNL Relativisic Heavy Ion Collider, we characterize $\sqrt{s_\mathrm{NN}}$ = 200 GeV p+Au collisions by event activity (EA) measured within the pseudorapidity range $eta$ $in$ [-5, -3.4] in the Au-going direction and report correlations between this EA and hard- and soft- scale particle production at midrapidity ($\eta$ $\in$ [-1, 1]). At the soft scale, charged particle production in low-EA p+Au collisions is comparable to that in p+p collisions and increases monotonically with increasing EA. At the hard scale, we report measurements of high transverse momentum (pT) jets in events of different EAs. In contrast with the soft particle production, high-pT particle production and EA are found to be inversely related. To investigate whether this is a signal of jet quenching in high-EA events, we also report ratios of pT imbalance and azimuthal separation of dijets in high- and low-EA events. Within our measurement precision, no significant differences are observed, disfavoring the presence of jet quenching in the highest 30% EA p+Au collisions at $\sqrt{s_\mathrm{NN}}$ = 200 GeV., Comment: 12 page, 9 figures

Published
2024
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8. Measurement of flow coefficients in high-multiplicity $p$+Au, $d$+Au and $^{3}$He$+$Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$=200 GeV

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Q., Chen, Z., Cheng, J., Cheng, Y., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Deshpande, A., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., Havener, L. B., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kołaś, J., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Markert, C., Matonoha, O., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Naim, C. J., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pal, S., Pandav, A., Panday, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Pinto, I. D. Ponce, Posik, M., Protzman, T. L., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Flow coefficients ($v_2$ and $v_3$) are measured in high-multiplicity $p$+Au, $d$+Au, and $^{3}$He$+$Au collisions at a center-of-mass energy of $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV using the STAR detector. The measurements utilize two-particle correlations with a pseudorapidity requirement of $|\eta| <$ 0.9 and a pair gap of $|\Delta\eta|>1.0$. The primary focus is on analysis methods, particularly the subtraction of non-flow contributions. Four established non-flow subtraction methods are applied to determine $v_n$, validated using the HIJING event generator. $v_n$ values are compared across the three collision systems at similar multiplicities; this comparison cancels the final state effects and isolates the impact of initial geometry. While $v_2$ values show differences among these collision systems, $v_3$ values are largely similar, consistent with expectations of subnucleon fluctuations in the initial geometry. The ordering of $v_n$ differs quantitatively from previous measurements using two-particle correlations with a larger rapidity gap, which, according to model calculations, can be partially attributed to the effects of longitudinal flow decorrelations. The prospects for future measurements to improve our understanding of flow decorrelation and subnucleonic fluctuations are also discussed., Comment: 29 pages, 25 figures

Published
2023

9. Production of Protons and Light Nuclei in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV with the STAR Detector

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Q., Chen, Z., Cheng, J., Cheng, Y., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Deshpande, A., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kołaś, J., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Markert, C., Matonoha, O., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Naim, C. J., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pal, S., Pandav, A., Panday, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T. L., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yu, N., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report the systematic measurement of protons and light nuclei production in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The transverse momentum ($p_{T}$) spectra of protons ($p$), deuterons ($d$), tritons ($t$), $^{3}\mathrm{He}$, and $^{4}\mathrm{He}$ are measured from mid-rapidity to target rapidity for different collision centralities. We present the rapidity and centrality dependence of particle yields ($dN/dy$), average transverse momentum ($\langle p_{T}\rangle$), yield ratios ($d/p$, $t/p$,$^{3}\mathrm{He}/p$, $^{4}\mathrm{He}/p$), as well as the coalescence parameters ($B_2$, $B_3$). The 4$\pi$ yields for various particles are determined by utilizing the measured rapidity distributions, $dN/dy$. Furthermore, we present the energy, centrality, and rapidity dependence of the compound yield ratios ($N_{p} \times N_{t} / N_{d}^{2}$) and compare them with various model calculations. The physics implications of those results on the production mechanism of light nuclei and on QCD phase structure are discussed., Comment: 17 pages, 17 figures

Published
2023
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10. Measurements of charged-particle multiplicity dependence of higher-order net-proton cumulants in $p$+$p$ collisions at $\sqrt{s} =$ 200 GeV from STAR at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kołaś, J., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matonoha, O., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pal, S., Pandav, A., Panday, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract

We report on the charged-particle multiplicity dependence of net-proton cumulant ratios up to sixth order from $\sqrt{s}=200$ GeV $p$+$p$ collisions at the Relativistic Heavy Ion Collider (RHIC). The measured ratios $C_{4}/C_{2}$, $C_{5}/C_{1}$, and $C_{6}/C_{2}$ decrease with increased charged-particle multiplicity and rapidity acceptance. Neither the Skellam baselines nor PYTHIA8 calculations account for the observed multiplicity dependence. In addition, the ratios $C_{5}/C_{1}$ and $C_{6}/C_{2}$ approach negative values in the highest-multiplicity events, which implies that thermalized QCD matter may be formed in $p$+$p$ collisions., Comment: 12 pages, 6 figures, accepted version by PLB

Published
2023
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11. Observation of the Antimatter Hypernucleus $^4_{\bar{\Lambda}}\overline{\hbox{H}}$

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pal, S., Pandav, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

At the origin of the Universe, asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know today. The origins of this asymmetry remain not completely understood yet. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter. Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and study their properties, hoping to shed some light on existing questions on the asymmetry between matter and antimatter. Here we report the first observation of the antimatter hypernucleus \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$}, composed of a $\bar{\Lambda}$ , an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider. In total, 15.6 candidate \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei \hbox{$^3_{\bar{\Lambda}}\overline{\hbox{H}}$} and \hbox{$^4_{\bar{\Lambda}}\overline{\hbox{H}}$} are measured and compared with the lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei and (anti)nuclei are also measured and compared with theoretical model predictions, shedding light on their production mechanisms., Comment: 28 pages, 5 figures in the main paper; 16 pages, 5 figures in the methods part

Published
2023
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12. Estimate of Background Baseline and Upper Limit on the Chiral Magnetic Effect in Isobar Collisions at $\sqrt{s_{\text{NN}}}=200$ GeV at the Relativistic Heavy-Ion Collider

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Alpatov, E., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Broodo, C., Cai, X. Z., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kechechyan, A., Khanal, A., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kraeva, A. Yu., Kravtsov, P., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Lin, Y., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Manikandhan, R., Margetis, S., Matis, H. S., McNamara, G., Mezhanska, O., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Nedorezov, E., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pal, S., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Povarov, A., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Trentalange, S., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

For the search of the chiral magnetic effect (CME), STAR previously presented the results from isobar collisions (${^{96}_{44}\text{Ru}}+{^{96}_{44}\text{Ru}}$, ${^{96}_{40}\text{Zr}}+{^{96}_{40}\text{Zr}}$) obtained through a blind analysis. The ratio of results in Ru+Ru to Zr+Zr collisions for the CME-sensitive charge-dependent azimuthal correlator ($\Delta\gamma$), normalized by elliptic anisotropy ($v_{2}$), was observed to be close to but systematically larger than the inverse multiplicity ratio. The background baseline for the isobar ratio, $Y = \frac{(\Delta\gamma/v_{2})^{\text{Ru}}}{(\Delta\gamma/v_{2})^{\text{Zr}}}$, is naively expected to be $\frac{(1/N)^{\text{Ru}}}{(1/N)^{\text{Zr}}}$; however, genuine two- and three-particle correlations are expected to alter it. We estimate the contributions to $Y$ from those correlations, utilizing both the isobar data and HIJING simulations. After including those contributions, we arrive at a final background baseline for $Y$, which is consistent with the isobar data. We extract an upper limit for the CME fraction in the $\Delta\gamma$ measurement of approximately $10\%$ at a $95\%$ confidence level on in isobar collisions at $\sqrt{s_{\text{NN}}} = 200$ GeV, with an expected $15\%$ difference in their squared magnetic fields., Comment: 19 pages, 14 figures

Published
2023
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13. Results on Elastic Cross Sections in Proton-Proton Collisions at $\sqrt{s} = 510$ GeV with the STAR Detector at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matis, H. S., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pal, S., Pandav, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report results on an elastic cross section measurement in proton-proton collisions at a center-of-mass energy $\sqrt{s}=510$ GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range $0.23 \leq -t \leq 0.67$ GeV$^2$. We find that a constant slope $B$ does not fit the data in the aforementioned $t$ range, and we obtain a much better fit using a second-order polynomial for $B(t)$. The $t$ dependence of $B$ is determined using six subintervals of $t$ in the STAR measured $t$ range, and is in good agreement with the phenomenological models. The measured elastic differential cross section $\mathrm{d}\sigma/\mathrm{dt}$ agrees well with the results obtained at $\sqrt{s} = 546$ GeV for proton--antiproton collisions by the UA4 experiment. We also determine that the integrated elastic cross section within the STAR $t$-range is $\sigma^\mathrm{fid}_\mathrm{el} = 462.1 \pm 0.9 (\mathrm{stat.}) \pm 1.1 (\mathrm {syst.}) \pm 11.6 (\mathrm {scale})$~$\mu\mathrm{b}$., Comment: 9 pages, 9 figures Version as published in Physics Letters B. HEPDATA: https://www.hepdata.net/record/144920

Published
2023
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14. Longitudinal and transverse spin transfer to $\Lambda$ and $\overline{\Lambda}$ hyperons in polarized $p$+$p$ collisions at $\sqrt{s} = 200$ GeV

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Anderson, D. M., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I. M., Dhamija, A., Di Carlo, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kimelman, B., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kramarik, L., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lisa, M. A., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Mukherjee, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Rana, A., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Szymanski, P. R., Tamis, A., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

The longitudinal and transverse spin transfers to $\Lambda$ ($\overline{\Lambda}$) hyperons in polarized proton-proton collisions are expected to be sensitive to the helicity and transversity distributions, respectively, of (anti-)strange quarks in the proton, and to the corresponding polarized fragmentation functions. We report improved measurements of the longitudinal spin transfer coefficient, $D_{LL}$, and the transverse spin transfer coefficient, $D_{TT}$, to $\Lambda$ and $\overline{\Lambda}$ in polarized proton-proton collisions at $\sqrt{s}$ = 200 GeV by the STAR experiment at RHIC. The data set includes longitudinally polarized proton-proton collisions with an integrated luminosity of 52 pb$^{-1}$, and transversely polarized proton-proton collisions with a similar integrated luminosity. Both data sets have about twice the statistics of previous results and cover a kinematic range of $|\eta_{\Lambda(\overline{\Lambda})}|$ $<$ 1.2 and transverse momentum $p_{T,{\Lambda(\overline{\Lambda})}}$ up to 8 GeV/$c$. We also report the first measurements of the hyperon spin transfer coefficients $D_{LL}$ and $D_{TT}$ as a function of the fractional jet momentum $z$ carried by the hyperon, which can provide more direct constraints on the polarized fragmentation functions.

Published
2023
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15. Reaction plane correlated triangular flow in Au+Au collisions at $\sqrt{s_{NN}}=3$ GeV

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matis, H. S., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pandav, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant $v_3$ signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at mid-rapidity, $dv_3/dy|_{(y=0)}$, opposite in sign compared to the slope for directed flow. No significant $v_3$ signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant nucleons is the result of stopping and nuclear geometry., Comment: 12 pages, 14 figures

Published
2023
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16. Upper Limit on the Chiral Magnetic Effect in Isobar Collisions at the Relativistic Heavy-Ion Collider

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Alpatov, E., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Broodo, C., Cai, X. Z., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kechechyan, A., Khanal, A., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kraeva, A. Yu., Kravtsov, P., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Lin, Y., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Manikandhan, R., Margetis, S., Matis, H. S., McNamara, G., Mezhanska, O., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Nedorezov, E., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pal, S., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Povarov, A., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Trentalange, S., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The chiral magnetic effect (CME) is a phenomenon that arises from the QCD anomaly in the presence of an external magnetic field. The experimental search for its evidence has been one of the key goals of the physics program of the Relativistic Heavy-Ion Collider. The STAR collaboration has previously presented the results of a blind analysis of isobar collisions (${^{96}_{44}\text{Ru}}+{^{96}_{44}\text{Ru}}$, ${^{96}_{40}\text{Zr}}+{^{96}_{40}\text{Zr}}$) in the search for the CME. The isobar ratio ($Y$) of CME-sensitive observable, charge separation scaled by elliptic anisotropy, is close to but systematically larger than the inverse multiplicity ratio, the naive background baseline. This indicates the potential existence of a CME signal and the presence of remaining nonflow background due to two- and three-particle correlations, which are different between the isobars. In this post-blind analysis, we estimate the contributions from those nonflow correlations as a background baseline to $Y$, utilizing the isobar data as well as Heavy Ion Jet Interaction Generator simulations. This baseline is found consistent with the isobar ratio measurement, and an upper limit of 10% at 95% confidence level is extracted for the CME fraction in the charge separation measurement in isobar collisions at $\sqrt{s_{\rm NN}}=200$ GeV., Comment: 8 pages, 4 figures

Published
2023
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17. Jet-hadron correlations with respect to the event plane in $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV Au+Au collisions in STAR

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, H-S., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pandav, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Angular distributions of charged particles relative to jet axes are studied in $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV Au+Au collisions as a function of the jet orientation with respect to the event plane. This differential study tests the expected path-length dependence of energy loss experienced by a hard-scattered parton as it traverses the hot and dense medium formed in heavy-ion collisions. A second-order event plane is used in the analysis as an experimental estimate of the reaction plane formed by the collision impact parameter and the beam direction. Charged-particle jets with $15 < p_{\rm T, jet} <$ 20 and $20 < p_{\rm T, jet} <$ 40 GeV/$c$ were reconstructed with the anti-$k_{\rm T}$ algorithm with radius parameter setting of (R=0.4) in the 20-50\% centrality bin to maximize the initial-state eccentricity of the interaction region. The reaction plane fit method is implemented to remove the flow-modulated background with better precision than prior methods. Yields and widths of jet-associated charged-hadron distributions are extracted in three angular bins between the jet axis and the event plane. The event-plane (EP) dependence is further quantified by ratios of the associated yields in different EP bins. No dependence on orientation of the jet axis with respect to the event plane is seen within the uncertainties in the kinematic regime studied. This finding is consistent with a similar experimental observation by ALICE in $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV Pb+Pb collision data.

Published
2023

18. Strangeness production in sNN = 3 GeV Au+Au collisions at RHIC

Author

Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Ball Cap, J. G., Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Calderón de la Barca Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, Y., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kołaś, J., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matonoha, O., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, B., Mondal, M. M., Mooney, I., Mrazkova, J., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pal, S., Pandav, A., Panday, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T. L., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Robertson, C. W., Robotkova, M., Rosales Aguilar, M. A., Roy, D., Roy Chowdhury, P., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Su, Y., Sumbera, M., Sun, C., Sun, X., Sun, Y., Sun, Y., Surrow, B., Svoboda, M., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Y., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, J., Wu, X., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Y., Xu, Z., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Ye, Z., Yi, L., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Y., Zhang, Y., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Published
2024
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19. Collision-energy Dependence of Deuteron Cumulants and Proton-deuteron Correlations in Au+Au collisions at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Broodo, C., Cai, X. Z., Caines, H., Sánchez, M. Calderónde la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Deppner, I. M., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Khanal, A., Khyzhniak, Y. V., Kikoła, D. P., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, D., Li, H-S., Li, H., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Luo, J., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Manikandhan, R., Margetis, S., Markert, C., Matis, H. S., McNamara, G., Mezhanska, O., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pal, S., Pandav, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Trentalange, S., Tribedy, P., Tripathy, S. K., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, K., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report the first measurements of cumulants, up to $4^{th}$ order, of deuteron number distributions and proton-deuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair $\sqrt{s_{NN}}$~=~7.7 to 200~GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is observed across all collision energies and centralities, consistent with the expectation from global baryon number conservation. The UrQMD model coupled with a phase-space coalescence mechanism qualitatively reproduces the collision-energy dependence of cumulant ratios and proton-deuteron correlations., Comment: 10 pages, 4 figures; published in Physics Letters B

Published
2023
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20. Event-by-event correlations between $\Lambda$ ($\bar{\Lambda}$) hyperon global polarization and handedness with charged hadron azimuthal separation in Au+Au collisions at $\sqrt{s_{\text{NN}}} = 27 \text{ GeV}$ from STAR

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Anderson, D. M., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Di Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kalinkin, D., Kang, K., Kapukchyan, D., Keane, D., Kechechyan, A., Kelsey, M., Kimelman, B., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kravtsov, P., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Global polarizations ($P$) of $\Lambda$ ($\bar{\Lambda}$) hyperons have been observed in non-central heavy-ion collisions. The strong magnetic field primarily created by the spectator protons in such collisions would split the $\Lambda$ and $\bar{\Lambda}$ global polarizations ($\Delta P = P_{\Lambda} - P_{\bar{\Lambda}} < 0$). Additionally, quantum chromodynamics (QCD) predicts topological charge fluctuations in vacuum, resulting in a chirality imbalance or parity violation in a local domain. This would give rise to an imbalance ($\Delta n = \frac{N_{\text{L}} - N_{\text{R}}}{\langle N_{\text{L}} + N_{\text{R}} \rangle} \neq 0$) between left- and right-handed $\Lambda$ ($\bar{\Lambda}$) as well as a charge separation along the magnetic field, referred to as the chiral magnetic effect (CME). This charge separation can be characterized by the parity-even azimuthal correlator ($\Delta\gamma$) and parity-odd azimuthal harmonic observable ($\Delta a_{1}$). Measurements of $\Delta P$, $\Delta\gamma$, and $\Delta a_{1}$ have not led to definitive conclusions concerning the CME or the magnetic field, and $\Delta n$ has not been measured previously. Correlations among these observables may reveal new insights. This paper reports measurements of correlation between $\Delta n$ and $\Delta a_{1}$, which is sensitive to chirality fluctuations, and correlation between $\Delta P$ and $\Delta\gamma$ sensitive to magnetic field in Au+Au collisions at 27 GeV. For both measurements, no correlations have been observed beyond statistical fluctuations., Comment: 10 pages, 10 figures; paper from the STAR Collaboration

Published
2023
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21. Observation of the electromagnetic field effect via charge-dependent directed flow in heavy-ion collisions at the Relativistic Heavy Ion Collider

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Alpatov, E., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Dash, A. P., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kechechyan, A., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kraeva, A. Yu., Kravtsov, P., Kumar, L., Labonte, M. C., Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, H-S., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Lin, Y., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Matis, H. S., McNamara, G., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Nedorezov, E., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Povarov, A., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Rana, A., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schaefer, B. C., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A. C., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Trentalange, S., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The deconfined quark-gluon plasma (QGP) created in relativistic heavy-ion collisions enables the exploration of the fundamental properties of matter under extreme conditions. Non-central collisions can produce strong magnetic fields on the order of $10^{18}$ Gauss, which offers a probe into the electrical conductivity of the QGP. In particular, quarks and anti-quarks carry opposite charges and receive contrary electromagnetic forces that alter their momenta. This phenomenon can be manifested in the collective motion of final-state particles, specifically in the rapidity-odd directed flow, denoted as $v_1(\mathsf{y})$. Here we present the charge-dependent measurements of $dv_1/d\mathsf{y}$ near midrapidities for $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ in Au+Au and isobar ($_{44}^{96}$Ru+$_{44}^{96}$Ru and $_{40}^{96}$Zr+$_{40}^{96}$Zr) collisions at $\sqrt{s_{\rm NN}}=$ 200 GeV, and in Au+Au collisions at 27 GeV, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The combined dependence of the $v_1$ signal on collision system, particle species, and collision centrality can be qualitatively and semi-quantitatively understood as several effects on constituent quarks. While the results in central events can be explained by the $u$ and $d$ quarks transported from initial-state nuclei, those in peripheral events reveal the impacts of the electromagnetic field on the QGP. Our data put valuable constraints on the electrical conductivity of the QGP in theoretical calculations.

Published
2023

22. Hyperon polarization along the beam direction relative to the second and third harmonic event planes in isobar collisions at $\sqrt{s_{NN}}$ = 200 GeV

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Anderson, D. M., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Di Carlo, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kechechyan, A., Kelsey, M., Kimelman, B., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kravtsov, P., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at $\sqrt{s_{NN}}$ = 200 GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild $p_T$ dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagree with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and $p_T$ dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy., Comment: 6 pages, 5 figures, Published in Physical Review Letters

Published
2023
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23. Measurement of electrons from open heavy-flavor hadron decays in Au+Au collisions at $\sqrt{s_{\rm NN}}=200$ GeV with the STAR detector

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Anderson, D. M., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I. M., Dhamija, A., Di Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Keane, D., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kimelman, B., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kramarik, L., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lisa, M. A., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Mukherjee, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Szymanski, P., Tamis, A., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report a new measurement of the production of electrons from open heavy-flavor hadron decays (HFEs) at mid-rapidity ($|y|<$ 0.7) in Au+Au collisions at $\sqrt{s_{\rm NN}}=200$ GeV. Invariant yields of HFEs are measured for the transverse momentum range of $3.5 < p_{\rm T} < 9$ GeV/$c$ in various configurations of the collision geometry. The HFE yields in head-on Au+Au collisions are suppressed by approximately a factor of 2 compared to that in $p$+$p$ collisions scaled by the average number of binary collisions, indicating strong interactions between heavy quarks and the hot and dense medium created in heavy-ion collisions. Comparison of these results with models provides additional tests of theoretical calculations of heavy quark energy loss in the quark-gluon plasma.

Published
2023
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24. Elliptic Flow of Heavy-Flavor Decay Electrons in Au+Au Collisions at $\sqrt{s_{_{\rm NN}}}$ = 27 and 54.4 GeV at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Anderson, D. M., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Cai, X. Z., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I. M., Dhamija, A., Di Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Keane, D., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kimelman, B., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kramarik, L., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lisa, M. A., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Mukherjee, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Szymanski, P., Tamis, A., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report on new measurements of elliptic flow ($v_2$) of electrons from heavy-flavor hadron decays at mid-rapidity ($|y|<0.8$) in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 27 and 54.4 GeV from the STAR experiment. Heavy-flavor decay electrons ($e^{\rm HF}$) in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$ = 54.4 GeV exhibit a non-zero $v_2$ in the transverse momentum ($p_{\rm T}$) region of $p_{\rm T}<$ 2 GeV/$c$ with the magnitude comparable to that at $\sqrt{s_{_{\rm NN}}}=200$ GeV. The measured $e^{\rm HF}$ $v_2$ at 54.4 GeV is also consistent with the expectation of their parent charm hadron $v_2$ following number-of-constituent-quark scaling as other light and strange flavor hadrons at this energy. These suggest that charm quarks gain significant collectivity through the evolution of the QCD medium and may reach local thermal equilibrium in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=54.4$ GeV. The measured $e^{\rm HF}$ $v_2$ in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=$ 27 GeV is consistent with zero within large uncertainties. The energy dependence of $v_2$ for different flavor particles ($\pi,\phi,D^{0}/e^{\rm HF}$) shows an indication of quark mass hierarchy in reaching thermalization in high-energy nuclear collisions., Comment: 12 pages, 7 figures, 1 table

Published
2023
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25. Energy Dependence of Intermittency for Charged Hadrons in Au+Au Collisions at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Anderson, D. M., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bielcik, J., Bielcikova, J., Brandenburg, J. D., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I. M., Dhamija, A., Di Carlo, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Gagliardi, C. A., Galatyuk, T., Gao, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Keane, D., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kimelman, B., Kincses, D., Kisel, I., Kiselev, A., Knospe, A. G., Ko, H. S., Kosarzewski, L. K., Kramarik, L., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Mukherjee, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, M., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B. R., Posik, M., Protzman, T., Prozorova, V., Pruthi, N. K., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Reed, R., Ritter, H. G., Robertson, C. W., Robotkova, M., Aguilar, M. A. Rosales, Roy, D., Chowdhury, P. Roy, Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Sato, S., Schmidke, W. B., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Stringfellow, B., Su, Y., Suaide, A. A. P., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z. W., Szymanski, P., Tamis, A., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Truhlar, T., Trzeciak, B. A., Tsai, O. D., Tsang, C. Y., Tu, Z., Tyler, J., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wielanek, D., Wieman, H., Wilks, G., Wissink, S. W., Witt, R., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Density fluctuations near the QCD critical point can be probed via an intermittency analysis in relativistic heavy-ion collisions. We report the first measurement of intermittency in Au$+$Au collisions at $\sqrt{s_\mathrm{_{NN}}}$ = 7.7-200 GeV measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The scaled factorial moments of identified charged hadrons are analyzed at mid-rapidity and within the transverse momentum phase space. We observe a power-law behavior of scaled factorial moments in Au$+$Au collisions and a decrease in the extracted scaling exponent ($\nu$) from peripheral to central collisions. The $\nu$ is consistent with a constant for different collisions energies in the mid-central (10-40\%) collisions. Moreover, the $\nu$ in the 0-5\% most central Au$+$Au collisions exhibits a non-monotonic energy dependence that reaches a possible minimum around $\sqrt{s_\mathrm{_{NN}}}$ = 27 GeV. The physics implications on the QCD phase structure are discussed., Comment: 8 pages, 4 figures. Published in Physics Letters B

Published
2023
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26. Measurements of the elliptic and triangular azimuthal anisotropies in central $^{3}$He+Au, $d$+Au and $p$+Au collisions at $\mbox{$\sqrt{s_{\mathrm{NN}}}$}$ = 200 GeV

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Anderson, D. M., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Di Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kimelman, B., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kravtsov, P., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, Md., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The elliptic ($v_2$) and triangular ($v_3$) azimuthal anisotropy coefficients in central $^{3}$He+Au, $d$+Au, and $p$+Au collisions at $\mbox{$\sqrt{s_{\mathrm{NN}}}$}$ = 200 GeV are measured as a function of transverse momentum ($p_{\mathrm{T}}$) at mid-rapidity ($|\eta|<$0.9), via the azimuthal angular correlation between two particles both at $|\eta|<$0.9. While the $v_2(p_{\mathrm{T}})$ values depend on the colliding systems, the $v_3(p_{\mathrm{T}})$ values are system-independent within the uncertainties, suggesting an influence on eccentricity from sub-nucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems., Comment: 5 pages, 4 figures

Published
2022

27. Beam Energy Dependence of Triton Production and Yield Ratio ($\mathrm{N}_t \times \mathrm{N}_p/\mathrm{N}_d^2$) in Au+Au Collisions at RHIC

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Anderson, D. M., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Baker, W., Cap, J. G. Ball, Barish, K., Bhagat, P., Bhasin, A., Bhatta, S., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Cai, X. Z., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chan, B. K., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, J. H., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Dale-Gau, G., Das, A., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Dhamija, A., Di Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J. L., Duckworth, E., Dunlop, J. C., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C. J., Feng, Y., Finch, E., Fisyak, Y., Flor, F. A., Fu, C., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Hamed, A., Han, Y., Harasty, M. D., Harris, J. W., Harrison-Smith, H., He, W., He, X. H., He, Y., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Huang, Y., Humanic, T. J., Isenhower, D., Isshiki, M., Jacobs, W. W., Jalotra, A., Jena, C., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kimelman, B., Kiselev, A., Knospe, A. G., Ko, H. S., Kochenda, L., Korobitsin, A. A., Kravtsov, P., Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Lacey, R., Landgraf, J. M., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Lin, T., Liu, C., Liu, F., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomicky, O., Longacre, R. S., Loyd, E. M., Lu, T., Lukow, N. S., Luo, X. F., Luong, V. B., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Mallick, D., Margetis, S., Matis, H. S., Mazer, J. A., McNamara, G., Mi, K., Minaev, N. G., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Mudrokh, A., Nagy, M. I., Nain, A. S., Nam, J. D., Nasim, Md., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nishitani, R., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Okubo, K., Page, B. S., Pak, R., Pan, J., Pandav, A., Pandey, A. K., Panebratsev, Y., Pani, T., Parfenov, P., Paul, A., Perkins, C., Pokhrel, B. R., Posik, M., Protzman, T., Pruthi, N. K., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S. K., Raha, N., Ray, R. L., Ritter, H. G., Robertson, C. W., Rogachevsky, O. V., Aguilar, M. A. Rosales, Roy, D., Ruan, L., Sahoo, A. K., Sahoo, N. R., Sako, H., Salur, S., Samigullin, E., Sato, S., Schmidke, W. B., Schmitz, N., Seger, J., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S. R., Sheikh, A. I., Shen, D. Y., Shen, K., Shi, S. S., Shi, Y., Shou, Q. Y., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M. J., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Su, Y., Sun, C., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Sweger, Z. W., Tamis, A., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Tlusty, D., Todoroki, T., Tokarev, M. V., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Tsang, C. Y., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vasiliev, A. N., Verkest, V., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, X., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Westfall, G. D., Wieman, H., Wilks, G., Wissink, S. W., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, N., Yu, Y., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, X., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, High Energy Physics - Theory, Nuclear Theory
Abstract

We report the triton ($t$) production in mid-rapidity ($|y| <$ 0.5) Au+Au collisions at $\sqrt{s_\mathrm{NN}}$= 7.7--200 GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider (RHIC). The nuclear compound yield ratio ($\mathrm{N}_t \times \mathrm{N}_p/\mathrm{N}_d^2$), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity ($dN_{ch}/d\eta$) and follows a scaling behavior. The $dN_{ch}/d\eta$ dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0\%-10\% most central collisions at 19.6 and 27 GeV, with a significance of 2.3$\sigma$ and 3.4$\sigma$, respectively, giving a combined significance of 4.1$\sigma$. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller $p_{T}$ acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed., Comment: 6 pages, 4 figures, Supplemental Material: http://link.aps.org/supplemental/10.1103/PhysRevLett.130.202301

Published
2022
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28. Characterisation and modelling of photovoltaic cells and modules under partial shading

Author

Atia, Abdulhamid M. Mahmud

Abstract

Partial shading in photovoltaic (PV) systems is an inevitable issue that significantly deteriorates their performance. This thesis presents a detailed experimental and theoretical study on the characterisation of solar cells and PV modules under partial shading. The primary focus of this research was to improve accuracy of modelling partially shaded PV modules without the need to include the avalanche breakdown term in the model. The research started by designing an equivalent circuit parameters extraction technique for solar cells and modules, which was used in the investigations of this study. The technique is based on adding a simple iterative process to an analytical method from the literature to optimise the selection of points used to calculate the slopes on current-voltage (I-V) curves. This resulted in an accurate technique with a mean absolute percentage error (MAPE) between calculated and experimental data of less than 2% for all I-V curves presented in this thesis. In addition, the technique showed a good repeatability of the parameters using the experimental set-up of this research. The relative standard deviations (RSDs) of the parameters extracted from four I-V curves measured in sequence were less than ±3%.This technique was then used in investigating the variations of a mono-crystalline (monoSi) solar cell parameters with shading. In addition, the effect of partial shading on the parameters was compared with that of reducing the irradiance uniformly on the cell area, where both effects were found to be nearly identical. The MAPE between I-V curves of partial shading and those of reducing the irradiance did not exceed 1% in two investigated cases. This investigation has confirmed that it is reasonably correct to enter opaque partial shading impact in PV models as a parameter that corresponds to reducing the irradiance uniformly over the whole cell area. Then, the variations of the equivalent circuit parameters with shading were entered in models for a single cell and a PV module to assess whether considering those variations will lead to any improvement in modelling accuracy. The results revealed that the single cell model did not exhibit an appreciable improvement in accuracy. By contrast, the PV module model showed a noticeable improvement at a region on the I-V and power-voltage (P-V) characteristics at which the shaded cell is working in the reverse bias. The parameter responsible for this improvement in accuracy was identified from a systematic study and found to be the shunt resistance (Rsh). Hence, it has been proposed to account for the variations with shading of only the photo-generated current (Iph) and Rsh when modelling partially shaded PV modules. The great advantage of this approach is that it provides an accurate modelling of the reverse bias region without the need to include the avalanche breakdown term in the model. Subsequently, this research focused on the response of a mono-Si PV module when individual solar cells were partially shaded. It was found that there is a correlation between the shape of I-V characteristics under partial shading and broken contact fingers of solar cells. Different experiments, including electroluminescence (EL) imaging, were carried-out to validate this correlation. The correlation reported in this thesis has proved the feasibility of a concept of detecting broken contact fingers in PV modules from measurements of I-V curves with individual cell partial shading under day light.

Published
2023

29. Rivet, RivetHZTool and HERA -- A validation effort for coding HERA measurements for Rivet

Author

Abdulhamid, M. I., Achilleos, A., Martinez, A. Bermudez, Bierlich, C., Bonomelli, Giorgia, Borkar, A., Buckley, A., Butterworth, J. M., Chithirasreemadam, M., Davydov, M., Banos, L. I. Estevez, Figueroa, K. Moral, Galván, A. B., Gütschow, C., Jung, H., Kim, S., Koennonkok, K., Quirós, A. León, Marsili, L., Mendizabal, M., Plätzer, S., Rahimova, N., Schmitt, S., Shannon, J., Singh, S. K., Süslü, C., Monfared, S. Taheri, Trakulphorm, N., van Mechelen, P., Verbytskyi, A., Wang, Q., Watt, G., Wilson, D., Wing, M., Yang, H., and Zhang, W.

Subjects
High Energy Physics - Phenomenology
Abstract

During the DESY summer student program 2021, young scientists from more than 13 different countries worked together, connecting from remote, to provide computer codes within the Rivet framework for 19 HERA measurements. Most of these measurements were originally available within the HZTool package, but no longer accessible for modern analysis packages such as Rivet. The temporary RivetHZTool interface was used to validate most of the new Rivet plugins., Comment: Part of the DESY summerstudent program 2021 (DESYsummer2021)

Published
2021

30. Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

Author

Abdulhamid, M. I., Al-Mashad, M. A., Martinez, A. Bermudez, Bonomelli, G., Bubanja, I., Crnkovic, N., Colombina, F., D'Anzi, B., Cerci, S., Davydov, M., Banos, L. I. Estevez, Forzano, N., Hautmann, F., Jung, H., Kim, S., Quiros, A. Leon, Martins, D. E., Mendizabal, M., Figueroa, K. Moral, Prestel, S., Monfared, S. Taheri, Süslü, C., Cerci, D. Sunar, van Kampen, A. M., Van Mechelen, P., Verbytskyi, A., Wang, Q., Yang, H., and Zhou, Y.

Subjects
High Energy Physics - Phenomenology
Abstract

The azimuthal correlation, $\Delta \phi_{12}$, of high transverse momentum jets in pp collisions at $\sqrt{s}=13$ TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of $\Delta \phi_{12}$ is observed. In the back-to-back region of $\Delta \phi_{12} \to \pi$, a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in $\alpha_s$, and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The $\Delta \phi_{12}$ measurements are also compared with predictions using MCatNLO together PYTHIA8, illustrating the importance of details of the parton shower evolution., Comment: 15 pages, 8 Figures

Published
2021
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31. Imaging shapes of atomic nuclei in high-energy nuclear collisions.

Author

STAR Collaboration, Abdulhamid, M. I., Aboona, B. E., Adam, J., Adams, J. R., Agakishiev, G., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aitbaev, A., Alekseev, I., Alpatov, E., Aparin, A., Aslam, S., Atchison, J., Averichev, G. S., Bairathi, V., Cap, J. G. Ball, Barish, K., and Bhagat, P.

Abstract

Atomic nuclei are self-organized, many-body quantum systems bound by strong nuclear forces within femtometre-scale space. These complex systems manifest a variety of shapes1–3, traditionally explored using non-invasive spectroscopic techniques at low energies4,5. However, at these energies, their instantaneous shapes are obscured by long-timescale quantum fluctuations, making direct observation challenging. Here we introduce the collective-flow-assisted nuclear shape-imaging method, which images the nuclear global shape by colliding them at ultrarelativistic speeds and analysing the collective response of outgoing debris. This technique captures a collision-specific snapshot of the spatial matter distribution within the nuclei, which, through the hydrodynamic expansion, imprints patterns on the particle momentum distribution observed in detectors6,7. We benchmark this method in collisions of ground-state uranium-238 nuclei, known for their elongated, axial-symmetric shape. Our findings show a large deformation with a slight deviation from axial symmetry in the nuclear ground state, aligning broadly with previous low-energy experiments. This approach offers a new method for imaging nuclear shapes, enhances our understanding of the initial conditions in high-energy collisions and addresses the important issue of nuclear structure evolution across energy scales.The collective-flow-assisted nuclear shape-imaging method images the nuclear global shape by colliding them at ultrarelativistic speeds and analysing the collective response of outgoing debris. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Observation of the antimatter hypernucleus H¯Λ¯4.

Author

Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Cap, J. G. Ball, Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bhosale, S. R., and Bielcik, J.

Abstract

At the origin of the Universe, an asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know it today. The origins of this asymmetry remain unknown so far. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter1–6. Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and to study their properties7–14, hoping to shed some light on the existing questions on the asymmetry between matter and antimatter. Here we report the observation of the antimatter hypernucleus H ¯ Λ ¯ 4 , composed of a Λ ¯ , an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider15,16. In total, 15.6 candidate H ¯ Λ ¯ 4 antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei H ¯ Λ ¯ 3 and H ¯ Λ ¯ 4 are measured and compared with the lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei (hypernuclei and/or antihypernuclei) and (anti)nuclei (nuclei and/or antinuclei) are also measured and compared with theoretical model predictions, shedding light on their production mechanisms.An antimatter hypernucleus formed by an anti-lambda hadron, an antiproton and two antineutrons was observed through its two-body decay after production in ultrarelativistic heavy-ion collisions. [ABSTRACT FROM AUTHOR]

Published
2024
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34. A critical evaluation of perceptions of drivers for organic food production in the UK

Author

Khanfer, Abdulhamid M., Rotherham, Ian, and Eastham, Jane

Subjects
338.1715840941
Abstract

This research was designed to evaluate and critically analyse organic food production in the UK. The main aims of this study were: 1) To investigate drivers and barriers for change from conventional to organic food for producers; for consumers; for supermarkets and small organic processors; 2) To quantity the impacts of interrelationships on organic farming growth and development; 3) To critically assess tensions between stakeholders. A mixed methods approach was applied in order to achieve these. This involved firstly an in-depth postal questionnaire survey (637 organic farmers) in different regions of England with selective follow-up telephone interviews. This was to assess drivers and barriers toward conversion and dealt solely with farmers that had gone through the process. Second, was a series of detailed personal interviews with representatives from major supermarket chains. Thirdly, interviews were conducted with the managers of five different types of alternative market outlets in South Yorkshire. Finally, information on consumer perspectives and issues was collected and interrogated from the extensive available literature. Representatives of the Soil Association were also contacted and interviewed. Mixed methods (quantitative and qualitative) were used to gather pertinent information, and where appropriate this was tested statistically using the Statistical Package for Social Sciences (SPSS) software. The qualitative information was analysed and interpreted. Qualitative findings of (10 interviews) were transcribed, critically analysed, triangulated, and interpreted. The research highlighted key issues and suggested critical tensions that may affect the future development of organic farming in the UK. All stakeholders seemed aware of the value of positive interrelationships but there was divergence in the interpretation of this perhaps reflecting stakeholder interests. Local producers viewed the big retailers' practice of importation for guarantee of supply, of quality, and of low price as an obstacle. The representatives of the supermarkets made claims about their commitment to local producers, to UK organic farmers and to others that seem to be exaggerated and certainly at odds with the views of other stakeholders. There were issues raised about confusion in terminology and in quality marking or labelling. The wider public do not understand the differences between local, organic, seasonal, and conservation products for example. Again, seasonality was raised as a serious issue. Sales direct from producer to consumer, and through specialist alternative outlets help provide routes to consumers that miss the supermarkets' stranglehold. They also help build trust and to educate and inform the consumer. Some of these issues are noted as areas for further research. The study assessed and highlighted for the first time some interesting and exciting aspects of the interrelationships between key stakeholders. It also identified critical factors in terms of how these may influence the growth and development of organic farming.

Published
2007

36. Genetic and environmental factors associated with Helicobacter pylori and peptic ulcer disease

Author

Alkout, Abdulhamid M.

Subjects
616.3
Abstract

The aims of the study were 1) to assess blood group and secretor status of local patients with peptic ulcer disease; 2) to determine if H. pylori binds to blood group antigens and if environmental factors such as fasting or smoking affect the binding; 3) to isolate bacterial adhesins that bind to the blood group antigens; 4) to determine if there are differences in the immune or inflammatory responses to H. pylori associated with ABO blood group or secretor status. There was a higher proportion of group O and non-secretors in the local patient group. In studies in which flow cytometry was used to assess bacterial binding to buccal epithelial cells or the gastric adenocarcinoma cell line (Kato III), binding of H. pylori was inhibited by pretreatment of the cells with monoclonal antibodies against Lewisa, Lewisb and H type 2 (the antigen of blood group O). Binding indices of H. pylori to buccal epithelial cells correlated with binding induces for H type 2 and Leb but not with Lea, suggesting the terminal fucose moieties of H type 2 and Lewis b are important epitopes for bacterial binding. Binding of H. pylori to buccal epithelial cells from smokers was significantly higher than to cells from non-smokers among patients referred to the gastroscopy clinic. In other experiments with cells from health volunteers, binding of H. pylori to cells from smokers was higher than to cells of non-smokers but the differences were not significant. Because each patient had fasted for approximately 12 hours before the cells were collected at the clinic, the effect of fasting and smoking were examined with buccal cells from1 5 pairs of smokers when fasting during Ramadan and after the fast when the donors were eating and drinking normally. In this group, binding of H. pylori and expression of H type 2 were significantly lower among the smokers.

Published
1997

37. Measurement of electrons from open heavy-flavor hadron decays in Au+Au collisions at <math> <msqrt> <msub> <mi>s</mi> <mi>NN</mi> </msub> </msqrt> </math> $$ \sqrt{s_{\textrm{NN}}} $$ = 200 GeV with the STAR detector

Author

Abdulhamid, M., Aboona, B., Adam, J., Adamczyk, L., Adams, J., Aggarwal, I., Aggarwal, M., Ahammed, Z., Anderson, D., Aschenauer, E., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Ball Cap, J., Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., Bhatta, S., Bielcik, J., Bielcikova, J., Brandenburg, J., Cai, X., Caines, H., Calderón de la Barca Sánchez, M., Cebra, D., Ceska, J., Chakaberia, I., Chaloupka, P., Chan, B., Chang, Z., Chatterjee, A., Chen, D., Chen, J., Chen, Z., Cheng, J., Cheng, Y., Choudhury, S., Christie, W., Chu, X., Crawford, H., Csanád, M., Dale-Gau, G., Das, A., Daugherity, M., Deppner, I., Dhamija, A., Carlo, L., Didenko, L., Dixit, P., Dong, X., Drachenberg, J., Duckworth, E., Dunlop, J., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Feng, C., Feng, Y., Finch, E., Fisyak, Y., Flor, F., Fu, C., Gagliardi, C., Galatyuk, T., Geurts, F., Ghimire, N., Gibson, A., Gopal, K., Gou, X., Grosnick, D., Gupta, A., Guryn, W., Hamed, A., Han, Y., Harabasz, S., Harasty, M., Harris, J., Harrison-Smith, H., He, W., He, X., He, Y., Herrmann, N., Holub, L., Hu, C., Hu, Q., Hu, Y., Huang, H., Huang, S., Huang, T., Huang, X., Huang, Y., Humanic, T., Isenhower, D., Isshiki, M., Jacobs, W., Jalotra, A., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jin, C., Ju, X., Judd, E., Kabana, S., Kabir, M., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Keane, D., Kelsey, M., Khyzhniak, Y., Kikoła, D., Kimelman, B., Kincses, D., Kisel, I., Kiselev, A., Knospe, A., Ko, H., Kosarzewski, L., Kramarik, L., Kumar, L., Kumar, S., Kunnawalkam Elayavalli, R., Lacey, R., Landgraf, J., Lauret, J., Lebedev, A., Lee, J., Leung, Y., Lewis, N., Li, C., Li, W., Li, X., Li, Y., Li, Z., Liang, X., Liang, Y., Licenik, R., Lin, T., Lisa, M., Liu, C., Liu, F., Liu, G., Liu, H., Liu, L., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W., Lomicky, O., Longacre, R., Loyd, E., Lu, T., Lukow, N., Luo, X., Ma, L., Ma, R., Ma, Y., Magdy, N., Mallick, D., Margetis, S., Markert, C., Matis, H., Mazer, J., McNamara, G., Mi, K., Mioduszewski, S., Mohanty, B., Mondal, M., Mooney, I., Mukherjee, A., Nagy, M., Nain, A., Nam, J., Nasim, M., Neff, D., Nelson, J., Nemes, D., Nie, M., Niida, T., Nishitani, R., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okubo, K., Page, B., Pak, R., Pan, J., Pandav, A., Pandey, A., Pani, T., Paul, A., Pawlik, B., Pawlowska, D., Perkins, C., Pluta, J., Pokhrel, B., Posik, M., Protzman, T., Prozorova, V., Pruthi, N., Przybycien, M., Putschke, J., Qin, Z., Qiu, H., Quintero, A., Racz, C., Radhakrishnan, S., Raha, N., Ray, R., Reed, R., Ritter, H., Robertson, C., Robotkova, M., Rosales Aguilar, M., Roy, D., Roy Chowdhury, P., Ruan, L., Sahoo, A., Sahoo, N., Sako, H., Salur, S., Sato, S., Schmidke, W., Schmitz, N., Seck, F-J., Seger, J., Seto, R., Seyboth, P., Shah, N., Shanmuganathan, P., Shao, T., Sharma, M., Sharma, N., Sharma, R., Sharma, S., Sheikh, A., Shen, D., Shen, K., Shi, S., Shi, Y., Shou, Q., Si, F., Singh, J., Singha, S., Sinha, P., Skoby, M., Smirnov, N., Söhngen, Y., Song, Y., Srivastava, B., Stanislaus, T., Stefaniak, M., Stewart, D., Stringfellow, B., Su, Y., Suaide, A., Sumbera, M., Sun, C., Sun, X., Sun, Y., Surrow, B., Sweger, Z., Szymanski, P., Tamis, A., Tang, A., Tang, Z., Tarnowsky, T., Thomas, J., Timmins, A., Tlusty, D., Todoroki, T., Tomkiel, C., Trentalange, S., Tribble, R., Tribedy, P., Truhlar, T., Trzeciak, B., Tsai, O., Tsang, C., Tu, Z., Tyler, J., Ullrich, T., Underwood, D., Upsal, I., Buren, G., Vanek, J., Vassiliev, I., Verkest, V., Videbæk, F., Voloshin, S., Wang, F., Wang, G., Wang, J., Wang, X., Wang, Y., Wang, Z., Webb, J., Weidenkaff, P., Westfall, G., Wielanek, D., Wieman, H., Wilks, G., Wissink, S., Witt, R., Wu, J., Wu, X., Wu, Y., Xi, B., Xiao, Z., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q., Xu, Y., Xu, Z., Yan, G., Yan, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, Y., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, J., Zhang, S., Zhang, W., Zhang, X., Zhang, Y., Zhang, Z., Zhao, F., Zhao, J., Zhao, M., Zhou, C., Zhou, J., Zhou, S., Zhou, Y., Zhu, X., Zurek, M., and Zyzak, M.

Abstract

We report a new measurement of the production of electrons from open heavy-flavor hadron decays (HFEs) at mid-rapidity (|y| < 0.7) in Au+Au collisions at s NN $$ \sqrt{s_{\textrm{NN}}} $$ = 200 GeV. Invariant yields of HFEs are measured for the transverse momentum range of 3.5 < p T < 9 GeV/c in various configurations of the collision geometry. The HFE yields in head-on Au+Au collisions are suppressed by approximately a factor of 2 compared to that in p + p collisions scaled by the average number of binary collisions, indicating strong interactions between heavy quarks and the hot and dense medium created in heavy-ion collisions. Comparison of these results with models provides additional tests of theoretical calculations of heavy quark energy loss in the quark-gluon plasma.

Published
2023

40. The impact and effectiveness of new coronavirus vaccine on disease outcome worldwide

Author

Abdulhamid M. Alkout and Tasneem A. Alkout

Subjects
mrna vaccine, Medicine (General), Disease outcome, business.industry, full vaccine, medicine.disease_cause, Virology, sars-cov-2, vector vaccine, inactivated virus vaccine, R5-920, covid-19, total vaccine, medicine, business, Coronavirus
Abstract

Introduction: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is spreading rapidly around the world caused serious respiratory disease leading to death, therefore vaccine is the effective way to control this pandemic. Scientists tried to produce safe and effective SARS-CoV-2 vaccines in record time and vaccination program started in December 2020. The aim of this study to determine the impact of SARS-CoV-2 vaccine on COVID-19 disease. Materials and methods: The COVID-19 cases data of post-vaccination and pre-vaccination were collected from Worldmeter website, and the percentage of vaccinated people data obtained from Statistics and Research Coronavirus Vaccinations. The statistical analyses performed with SPSS software version 16.0. Results: The results showed countries with higher percentage of full dose vaccinated people correlated strongly with decrease of death and the severity of the disease among their infected population. This study showed that different vaccine mechanism against SARS-CoV-2 virus of more than 23.5% of vaccination people with full dose vaccine is effective to decrease death and serious symptoms of COVID-19 disease and increasing the recovery rate. Conclusions: Different mechanism type of full dose vaccine against SARS-CoV-2 is effective to decrease death and serious symptoms of COVID-19 disease with increasing recovery rate. It was difficult to assess the effect of single dose alone, therefore more studies are recommended to assess the effect of single dose vaccine with COVID-19 disease outcome and to determine if the vaccine will accelerate the period of recovery rate and reduce the infectious period time in each country.

Published
2021

42. Measurement of electrons from open heavy-flavor hadron decays in Au+Au collisions at sNN = 200 GeV with the STAR detector.

Author

Abdulhamid, M. I., Aboona, B. E., Adam, J., Adamczyk, L., Adams, J. R., Aggarwal, I., Aggarwal, M. M., Ahammed, Z., Anderson, D. M., Aschenauer, E. C., Aslam, S., Atchison, J., Bairathi, V., Baker, W., Ball Cap, J. G., Barish, K., Bellwied, R., Bhagat, P., Bhasin, A., and Bhatta, S.

Subjects
FLAVOR in particle physics, HADRON decay, QUARK-gluon plasma, CONFIGURATIONS (Geometry), ELECTRONS, QUARKS, FLAVOR, COLLISION broadening
Abstract

We report a new measurement of the production of electrons from open heavy-flavor hadron decays (HFEs) at mid-rapidity (|y| < 0.7) in Au+Au collisions at s NN = 200 GeV. Invariant yields of HFEs are measured for the transverse momentum range of 3.5 < pT< 9 GeV/c in various configurations of the collision geometry. The HFE yields in head-on Au+Au collisions are suppressed by approximately a factor of 2 compared to that in p + p collisions scaled by the average number of binary collisions, indicating strong interactions between heavy quarks and the hot and dense medium created in heavy-ion collisions. Comparison of these results with models provides additional tests of theoretical calculations of heavy quark energy loss in the quark-gluon plasma. [ABSTRACT FROM AUTHOR]

Published
2023
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43. Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

Author

Abdulhamid, M. I., primary, Al-Mashad, M. A., additional, Martinez, A. Bermudez, additional, Bonomelli, G., additional, Bubanja, I., additional, Crnković, N., additional, Colombina, F., additional, D’Anzi, B., additional, Cerci, S., additional, Davydov, M., additional, Banos, L. I. Estevez, additional, Forzano, N., additional, Hautmann, F., additional, Jung, H., additional, Kim, S., additional, Quirós, A. León, additional, Martins, D. E., additional, Mendizabal, M., additional, Figueroa, K. Moral, additional, Prestel, S., additional, Monfared, S. Taheri, additional, Süslü, C., additional, Cerci, D. Sunar, additional, van Kampen, A. M., additional, Van Mechelen, P., additional, Verbytskyi, A., additional, Wang, Q., additional, Yang, H., additional, and Zhou, Y., additional

Published
2022
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44. Incidence of rubella antibodies among pregnant women in third trimester attending antenatal clinic at University of Maiduguri Teaching Hospital (UMTH)

Author

Bulama, A. A., Abdulhamid, M. B., Mohammed, K. B., and Soji, O. B.

Subjects
Rubella virus, incidence, Trimester
Abstract

Background: Rubella is caused by a positive sense RNA virus of the family Rubiviridae. This is the only non-arthropod borne virus in the family and the etiologic agent of rubellaaffecting people of all ages and sex. The virus has been identified as a human teratogen capable of causing a spectrum of birth defects often collectively referred to as congenital rubella syndrome (CRS) or death of a developing fetus, especially if the viral infection is acquired in the early months.Aim: This study was aimed at determining the incidence of rubella IgG/IgM antibodies among pregnant women in their third trimester attending antenatal clinic of University ofMaiduguri, Teaching Hospital (UMTH).Methodology: Ninety (90) venous blood samples were collected from pregnant women at their third trimester, the samples were separated and the sera were screened for rubella IgG and IgM using RUB anti-RV (IgG) and (IgM) kit based on indirect Enzyme Linked Immunosorbent Assay (ELISA) method.Results: Eighty nine (98.9%) and five (5.6%) had rubella virus specific IgG antibody (IgG sero positive) and rubella virus specific IgM antibody (IgM sero positive) respectively. Women within the age bracket of 21-25 and 26-30 had the highest incidence 2.22% of rubella specific IgM, then followed by the age groups 15-20 with 1.11%. While zero percent (0%) incidence was reported among the age groups 31-35 and 36-40. Women within the age bracket (15-20) had the least (10%) incidence of rubella specific IgG antibody, and then followed by the age group (36-40) with 12.2%, age group (31-35) with 23.3%, age group (21-25) with 24.4% and lastly the age group (26-30) with 28.9%.Conclusion: This study revealed that there are still a percentage of women 1(1.1%) at the childbearing age that had no evidence of rubella immunity (IgG seronegative) and are at risk of being infected with the virus especially during the first trimester of pregnancy which can result to congenital defects with fatal consequences. As such, there is need for more sero-surveys on rubella in the country to support the advocacy for the inclusion of rubella vaccination in the National Programme on Immunization (NPI).

Published
2021

46. Hartmann pouch herniation in Calot’s triangle: A case report

Author

Malek A. Al-Omari, Ra’ed Al-Jarrah, Tariq Almnaizel, Abdulhamid M. Al-Abadi, Tawfiq Alnawafleh, and Eman A. Al-Oudat

Subjects
medicine.medical_specialty, Calot’s triangle, Gallbladder Stone, Article, 03 medical and health sciences, Laparoscopic cholecystectomy, 0302 clinical medicine, medicine, Hepatology, Hartmann pouch, business.industry, General surgery, Gastroenterology, Emergency department, medicine.disease, medicine.anatomical_structure, Biliary tract, 030220 oncology & carcinogenesis, Cholecystitis, Cystic duct, 030211 gastroenterology & hepatology, Surgery, Presentation (obstetrics), Differential diagnosis, Complication, business
Abstract

Highlights • There are many atypical anatomic structural variations of the biliary tree. • The anatomical variations can be diagnosed either intra-operatively or pre-operatively. • Surgeon’s experience and knowledge are essential to form the best surgical decision. • A second opinion of a hepatobiliary surgeon decreases avoidable complex injury to biliary tract in selective cases. • Fine handling of hepatocystic triangle and skeletonization of porta hepatis are the main principles of surgery., Introduction Laparoscopic cholecystectomy is one of the most frequent operations performed around the world. Some pathological findings are particularly rare and difficult to diagnose preoperatively. Here, we report a case of a patient who presented to our hospital with calculus cholecystitis with a unique Intraoperative finding of Hartmann pouch herniation through hepatocystic triangle. The aim of the study is to consider Hartmann pouch herniation as a rare differential diagnosis of gallbladder stone complication. Presentation of case We present a 48-year-old male who came to our emergency department complaining of constant epigastric abdominal pain lasting 3 h with vomiting. Utilizing chemistry laboratory studies and radiological studies, the final diagnosis was acute calculus cholecystitis. Early laparoscopic cholecystectomy was done and revealed Hartmann pouch herniation through the Calot’s triangle. This herniation resulted in strangulation of the Hartmann pouch and displacement of the cystic duct and artery anteriorly. Discussion The biliary tract is liable for congenital anomalies. These anatomical variations can be diagnosed either intra-operatively or pre-operatively using radiological imaging. Hartmann pouch herniation is a new finding that we encountered in this case. Conclusion Profound surgeons’ anatomical knowledge is essential for the safety of patients, especially for hepatobiliary surgeries due to the wide variations in normal and pathological anatomy. Using critical view of safety can decrease avoidable complications. Consulting specialized hepatobiliary surgeon is preferred when dealing with such cases.

Published
2020

48. Design of high-performance electrochemical sensor based on SnS2 nanoplates and ionic liquid-modified carbon paste electrode for determination of hydrazine in water samples

Author

Afsaneh Haji Alizadeh, Samaneh Salemi Najaf Abadi, and Abdulhamid Morshidi Nozar

Subjects
Electrochemical sensing, hydrazine, tin disulfide nanoplates, ionic liquid, real water samples, Chemistry, QD1-999
Abstract

Designing effective and accurate analytical techniques to determine hydrazine is essential for preserving the environment. Herein, an electrochemical sensor based on a carbon paste electrode (CPE) modified with SnS2 nanoplates (SnS2NPs) and ionic liquid (IL) was presented for determination of hydrazine in water samples. The SnS2NPs were synthesized using the hydrothermal method and characterized through field emission scanning electron microscope, Fourier transform infrared spectrometer and energy dispersive spectroscopy. The use of cyclic voltammetry in electrochemical investigations has shown that incorporating IL and SnS2NPs in an electrochemical sensor significantly improves its efficiency. These results in a considerable increase in the oxidation peak current and a decrease in the oxidation peak potential of hydrazine compared to an unmodified CPE. The method of differential pulse voltammetry was utilized to accurately measure the quantity of hydrazine. The SnS2NPs/ILCPE showed improved sensing capabilities, resulting in a noticeable sensitivity of 0.0747 µA/µM and a low limit of detection of 0.05 µM for a broad linear range of hydrazine concentration from 0.08 µM to 450.0 µM. In addition, the SnS2NPs/ILCPE sensor was successfully utilized to measure the amount of hydrazine present in water samples, with a recovery range of 96.0 to 104.4 %. The relative standard deviation was found to be lower than 3.6 % (n = 5), indicating that the developed sensor is suitable for accurately determining hydrazine in water samples with high sensitivity.

Published
2024
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49. Nutrient Content and in Vitro Digestibility of Apple Pomace Derived from Three Different Apple Cultivars

Author

Abdulhamid Muhammad Garba and Sema Yaman Fırıncıoğlu

Subjects
agro-industrial waste products, nutritional value, apple pomace, in-vitro digestibility, ruminant feeding, Agriculture, Agriculture (General), S1-972
Abstract

This study focused on evaluating the nutritional characteristics and in vitro true digestibility of apple pomace derived from three apple cultivars: Golden Delicious, Starking, and Granny Smith (Malus domestica Borkh). These apple cultivars were sourced from the local market in Nigde, Turkiye. Statistical analyses, including one-way analysis of variance (ANOVA) and Duncan's test, were employed to assess variations among the apple pomace samples. Results indicated that, except for in vitro true digestibility, there were no significant variations in the chemical composition and total phenolic matter contents among the apple pomaces (P>0.05). However, Granny Smith apple pomace exhibited distinct features, such as higher neutral detergent fiber content (29.80%), elevated crude protein levels (5.09%) and substantial acid detergent fiber (25.30%) values. In contrast, Starking apple pomace displayed superior air-dry matter (27.24%), while Golden Delicious showcased enhanced dry matter (95.3%) and ash content (2.00%). Regarding total phenolic matter contents, Granny Smith excelled with 112.4 mg GAE/100g, outperforming Starking (103 mg GAE/100g) and Golden Delicious (75.8 mg GAE/100g). Crucially, Starking demonstrated superior in vitro true digestibility, with values reaching 92.36% (as received) and 92.23% (dry matter). Granny Smith, in comparison to Golden Delicious and Starking, displayed significantly different neutral detergent fiber digestibility (P

Published
2024
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