Author: "Bland, P. A." / Topic: physical sciences - Searchworks@Jio Institute Digital Library Search Results

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145 results on '"Bland, P. A."'

1. High-precision measurement of the W boson mass with the CDF II detector

Author: Collaboration†‡, CDF, Aaltonen, T, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, JA, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, VE, Barnett, BA, Barria, P, Bartos, P, Bauce, M, Bedeschi, F, Behari, S, Bellettini, G, Bellinger, J, Benjamin, D, Beretvas, A, Bhatti, A, Bland, KR, Blumenfeld, B, Bocci, A, Bodek, A, Bortoletto, D, Boudreau, J, Boveia, A, Brigliadori, L, Bromberg, C, Brucken, E, Budagov, J, Budd, HS, Burkett, K, Busetto, G, Bussey, P, Butti, P, Buzatu, A, Calamba, A, Camarda, S, Campanelli, M, Carls, B, Carlsmith, D, Carosi, R, Carrillo, S, Casal, B, Casarsa, M, Castro, A, Catastini, P, Cauz, D, Cavaliere, V, Cerri, A, Cerrito, L, Chen, YC, Chertok, M, Chiarelli, G, Chlachidze, G, Cho, K, Chokheli, D, Clark, A, Clarke, C, Convery, ME, Conway, J, Corbo, M, Cordelli, M, Cox, CA, Cox, DJ, Cremonesi, M, Cruz, D, Cuevas, J, Culbertson, R, d’Ascenzo, N, Datta, M, de Barbaro, P, Demortier, L, Deninno, M, D’Errico, M, Devoto, F, Di Canto, A, Di Ruzza, B, Dittmann, JR, Donati, S, D’Onofrio, M, Dorigo, M, Driutti, A, Ebina, K, Edgar, R, Elagin, A, Erbacher, R, and Errede, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, CDF Collaboration†‡, General Science & Technology
Abstract: The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain [Formula: see text], the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.
Published: 2022

2. Measurement of the charge asymmetry of electrons from the decays of W bosons produced in pp¯ collisions at s=1.96 TeV

Author: Aaltonen, T, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, JA, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, VE, Barnett, BA, Barria, P, Bartos, P, Bauce, M, Bedeschi, F, Behari, S, Bellettini, G, Bellinger, J, Benjamin, D, Beretvas, A, Bhatti, A, Bland, KR, Blumenfeld, B, Bocci, A, Bodek, A, Bortoletto, D, Boudreau, J, Boveia, A, Brigliadori, L, Bromberg, C, Brucken, E, Budagov, J, Budd, HS, Burkett, K, Busetto, G, Bussey, P, Butti, P, Buzatu, A, Calamba, A, Camarda, S, Campanelli, M, Canelli, F, Carls, B, Carlsmith, D, Carosi, R, Carrillo, S, Casal, B, Casarsa, M, Castro, A, Catastini, P, Cauz, D, Cavaliere, V, Cerri, A, Cerrito, L, Chen, YC, Chertok, M, Chiarelli, G, Chlachidze, G, Cho, K, Chokheli, D, Clark, A, Clarke, C, Convery, ME, Conway, J, Corbo, M, Cordelli, M, Cox, CA, Cox, DJ, Cremonesi, M, Cruz, D, Cuevas, J, Culbertson, R, d’Ascenzo, N, Datta, M, de Barbaro, P, Demortier, L, Deninno, M, D’Errico, M, Devoto, F, Di Canto, A, Di Ruzza, B, Dittmann, JR, Donati, S, D’Onofrio, M, Dorigo, M, Driutti, A, Ebina, K, Edgar, R, Elagin, A, Erbacher, R, and Errede, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract: At the Fermilab Tevatron proton-antiproton (pp¯) collider, high-mass electron-neutrino (eν) pairs are produced predominantly in the process pp¯→W(→eν)+X. The asymmetry of the electron and positron yield as a function of their pseudorapidity constrain the slope of the ratio of the u- to d-quark parton distributions versus the fraction of the proton momentum carried by the quarks. This paper reports on the measurement of the electron-charge asymmetry using the full data set recorded by the Collider Detector at Fermilab in 2001-2011 and corresponding to 9.1 fb-1 of integrated luminosity. The measurement significantly improves the precision of the Tevatron constraints on the parton-distribution functions of the proton. Numerical tables of the measurement are provided.
Published: 2021

3. Measurement of transverse single-spin asymmetries of π0 and electromagnetic jets at forward rapidity in 200 and 500 GeV transversely polarized proton-proton collisions

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, and Holub, L
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, hep-ex
Abstract: The STAR Collaboration reports measurements of the transverse single-spin asymmetry (TSSA) of inclusive π0 at center-of-mass energies (s) of 200 GeV and 500 GeV in transversely polarized proton-proton collisions in the pseudo-rapidity region 2.7 to 4.0. The results at the two different energies show a continuous increase of the TSSA with Feynman-x, and, when compared to previous measurements, no dependence on s from 19.4 GeV to 500 GeV is found. To investigate the underlying physics leading to this large TSSA, different topologies have been studied. π0 with no nearby particles tend to have a higher TSSA than inclusive π0. The TSSA for inclusive electromagnetic jets, sensitive to the Sivers effect in the initial state, is substantially smaller, but shows the same behavior as the inclusive π0 asymmetry as a function of Feynman-x. To investigate final-state effects, the Collins asymmetry of π0 inside electromagnetic jets has been measured. The Collins asymmetry is analyzed for its dependence on the π0 momentum transverse to the jet thrust axis and its dependence on the fraction of jet energy carried by the π0. The asymmetry was found to be small in each case for both center-of-mass energies. All the measurements are compared to QCD-based theoretical calculations for transverse-momentum-dependent parton distribution functions and fragmentation functions. Some discrepancies are found, which indicates new mechanisms might be involved.
Published: 2021

4. Methods for a blind analysis of isobar data collected by the STAR collaboration

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, and Horvat, S
Subjects: Nuclear and Plasma Physics, Physical Sciences, Blind analysis, Chiral magnetic effect, Heavy-ion collisions, nucl-ex, hep-ex, Nuclear & Particles Physics
Abstract: In 2018, the STAR collaboration collected data from 4496Ru+4496Ru and 4096Zr+4096Zr at sNN=200 GeV to search for the presence of the chiral magnetic effect in collisions of nuclei. The isobar collision species alternated frequently between 4496Ru+4496Ru and 4096Zr+4096Zr. In order to conduct blind analyses of studies related to the chiral magnetic effect in these isobar data, STAR developed a three-step blind analysis procedure. Analysts are initially provided a “reference sample” of data, comprised of a mix of events from the two species, the order of which respects time-dependent changes in run conditions. After tuning analysis codes and performing time-dependent quality assurance on the reference sample, analysts are provided a species-blind sample suitable for calculating efficiencies and corrections for individual ≈ 30 -min data-taking runs. For this sample, species-specific information is disguised, but individual output files contain data from a single isobar species. Only run-by-run corrections and code alteration subsequent to these corrections are allowed at this stage. Following these modifications, the “frozen” code is passed over the fully un-blind data, completing the blind analysis. As a check of the feasibility of the blind analysis procedure, analysts completed a “mock data challenge,” analyzing data from Au + Au collisions at sNN=27 GeV, collected in 2018. The Au + Au data were prepared in the same manner intended for the isobar blind data. The details of the blind analysis procedure and results from the mock data challenge are presented.
Published: 2021

5. Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, and Hong, Y
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, STAR Collaboration, nucl-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: Global polarization of Ξ and Ω hyperons has been measured for the first time in Au+Au collisions at sqrt[s_{NN}]=200 GeV. The measurements of the Ξ^{-} and Ξ[over ¯]^{+} hyperon polarization have been performed by two independent methods, via analysis of the angular distribution of the daughter particles in the parity violating weak decay Ξ→Λ+π, as well as by measuring the polarization of the daughter Λ hyperon, polarized via polarization transfer from its parent. The polarization, obtained by combining the results from the two methods and averaged over Ξ^{-} and Ξ[over ¯]^{+}, is measured to be ⟨P_{Ξ}⟩=0.47±0.10(stat)±0.23(syst)% for the collision centrality 20%-80%. The ⟨P_{Ξ}⟩ is found to be slightly larger than the inclusive Λ polarization and in reasonable agreement with a multiphase transport model. The ⟨P_{Ξ}⟩ is found to follow the centrality dependence of the vorticity predicted in the model, increasing toward more peripheral collisions. The global polarization of Ω, ⟨P_{Ω}⟩=1.11±0.87(stat)±1.97(syst)% was obtained by measuring the polarization of daughter Λ in the decay Ω→Λ+K, assuming the polarization transfer factor C_{ΩΛ}=1.
Published: 2021

6. Comparison of transverse single-spin asymmetries for forward π0 production in polarized pp, pAl and pAu collisions at nucleon pair c.m. energy sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, and Hong, Y
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, hep-ex
Abstract: The STAR collaboration reports a measurement of the transverse single-spin asymmetries, AN, for neutral pions produced in polarized proton collisions with protons (pp), with aluminum nuclei (pAl) and with gold nuclei (pAu) at a nucleon-nucleon center-of-mass energy of 200 GeV. Neutral pions are observed in the forward direction relative to the transversely polarized proton beam, in the pseudorapidity region 2.7
Published: 2021

7. Measurements of dihadron correlations relative to the event plane in Au+Au collisions at GeV * *Supported in part by the Offices of NP and HEP within the U.S. DOE Office of Science, the U.S. NSF, the Sloan Foundation, the DFG cluster of excellence ‘Origin and Structure of the Universe’ of Germany, CNRS/IN2P3, STFC and EPSRC of the United Kingdom, FAPESP CNPq of Brazil, Ministry of Ed. and Sci. of the Russian Federation, NNSFC, CAS, MoST, and MoE of China, GA and MSMT of the Czech Republic, FOM and NWO of the Netherlands, DAE, DST, and CSIR of India, Polish Ministry of Sci. and Higher Ed., Korea Research Foundation, Ministry of Sci., Ed. and Sports of the Rep. Of Croatia, Russian Ministry of Sci. and Tech, and RosAtom of Russia

Author: Agakishiev, H, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Alford, J, Anderson, BD, Anson, CD, Arkhipkin, D, Averichev, GS, Balewski, J, Beavis, DR, Behera, NK, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Biritz, B, Bland, LC, Borowski, W, Bouchet, J, Braidot, E, Brandin, AV, Bridgeman, A, Brovko, SG, Bruna, E, Bueltmann, S, Bunzarov, I, Burton, TP, Cai, XZ, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chajecki, Z, Chaloupka, P, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Choi, KE, Christie, W, Chung, P, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Dash, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Derevschikov, AA, de Souza, R Derradi, Didenko, L, Djawotho, P, Dogra, SM, Dong, X, Drachenberg, JL, Draper, JE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Estienne, M, Eun, L, Evdokimov, O, Fatemi, R, Fedorisin, J, Feng, A, Fersch, RG, Filip, P, Finch, E, Fine, V, Fisyak, Y, Gagliardi, CA, Gangadharan, DR, Geromitsos, A, Geurts, F, Ghosh, P, Gorbunov, YN, Gordon, A, Grebenyuk, O, Grosnick, D, Guertin, SM, Gupta, A, Guryn, W, Haag, B, Hajkova, O, and Hamed, A
Subjects: Nuclear and Plasma Physics, Physical Sciences, relativistic heavy ion collisions, dihadron correlations, jet-medium interactions, anisotropic flow background, event plane, nucl-ex, nucl-th, NSD-Relativistic Nuclear Collisions, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: Dihadron azimuthal correlations containing a high transverse momentum (pT) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20%-60%) Au+Au collisions at GeV as a function of the trigger particle's azimuthal angle relative to the event plane, . The azimuthal correlation is studied as a function of both the trigger and associated particle . The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with , with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity correlation) appears to drop with increasing while the jet-like component remains approximately constant. The correlation functions are further studied with the subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the -dependence of the ridge or the away-side double-peak structure. The dropping ridge with could be attributed to a -dependent elliptic anisotropy; however, the physics mechanism of the ridge remains an open question. Even with a -dependent elliptic flow, the away-side correlation structure is robust. These results, with extensive systematic studies of the dihadron correlations as a function of , trigger and associated particle , and the pseudo-rapidity range , should provide stringent inputs to help understand the underlying physics mechanisms of jet-medium interactions in high energy nuclear collisions.
Published: 2021

8. Nonmonotonic Energy Dependence of Net-Proton Number Fluctuations

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, and Horvat, S
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, STAR Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: Nonmonotonic variation with collision energy (sqrt[s_{NN}]) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of sqrt[s_{NN}] with 3.1 σ significance for head-on (central) gold-on-gold (Au+Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of sqrt[s_{NN}].
Published: 2021

9. Measurements of W and Z/γ* cross sections and their ratios in p+p collisions at RHIC

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, He, Y, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, and Horvat, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex
Abstract: We report on the W and Z/γ∗ differential and total cross sections as well as the W+/W- and (W++W-)/(Z/γ∗) cross section ratios measured by the STAR experiment at RHIC in p+p collisions at s=500 GeV and 510 GeV. The cross sections and their ratios are sensitive to quark and antiquark parton distribution functions. In particular, at leading order, the W cross section ratio is sensitive to the d¯/ū ratio. These measurements were taken at high Q2∼MW2,MZ2 and can serve as input into global analyses to provide constraints on the sea quark distributions. The results presented here combine three STAR datasets from 2011, 2012, and 2013, accumulating an integrated luminosity of 350 pb-1. We also assess the expected impact that our W+/W- cross section ratios will have on various quark distributions, and find sensitivity to the ū-d¯ and d¯/ū distributions.
Published: 2021

10. Measurement of groomed jet substructure observables in p+p collisions at s = 200 GeV with STAR

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, and Huang, HZ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, Jet substructure, SoftDrop, Splitting function, Groomed jet radius, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: In this letter, measurements of the shared momentum fraction (zg) and the groomed jet radius (Rg), as defined in the SoftDrop algorithm, are reported in p+p collisions at s=200 GeV collected by the STAR experiment. These substructure observables are differentially measured for jets of varying resolution parameters from R=0.2−0.6 in the transverse momentum range 15
Published: 2020

11. Measurement of inclusive charged-particle jet production in Au + Au collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, and Huang, HZ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, Nuclear and plasma physics
Abstract: The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at sNN=200 GeV. Jets are reconstructed with the anti-kT algorithm using charged tracks with pseudorapidity |η|
Published: 2020

12. Measurement of inclusive J/ψ polarization in p+p collisions at s=200 GeV by the STAR experiment

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bueltmann, S, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, nucl-ex
Abstract: We report on new measurements of inclusive J/ψ polarization at midrapidity in p+p collisions at s=200 GeV by the STAR experiment at the Relativistic Heavy Ion Collider. The polarization parameters, λθ, λφ, and λθφ, are measured as a function of transverse momentum (pT) in both the helicity and Collins-Soper (CS) reference frames within pT
Published: 2020

13. Measurement of away-side broadening with self-subtraction of flow in Au+Au collisions at GeV * * This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S. National Science Foundation, the Ministry of Education and Science of the Russian Federation, National Natural Science Foundation of China, Chinese Academy of Science, the Ministry of Science and Technology of China and the Chinese Ministry of Education, the Higher Education Sprout Project by Ministry of Education at NCKU, the National Research Foundation of Korea, Czech Science Foundation and Ministry of Education, Youth and Sports of the Czech Republic, Hungarian National Research, Development and Innovation Office, New National Excellency Programme of the Hungarian Ministry of Human Capacities, Department of Atomic Energy and Department of Science and Technology of the Government of India, the National Science Centre of Poland, the Ministry of Science, Education and Sports of the Republic of Croatia

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Physical Sciences, Quality Education, di-hadron correlations, jet, heavy-ion, nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
Abstract: High transverse momentum (PT) particle production is suppressed owing to the parton (jet) energy loss in the hot dense medium created in relativistic heavy-ion collisions. Redistribution of energy at low-to-modest PT has been difficult to measure, owing to large anisotropic backgrounds. We report a data-driven method for background evaluation and subtraction, exploiting the away-side pseudorapidity gaps, to measure the jetlike correlation shape in Au+Au collisions at √SNN = 200 GeV in the STAR experiment. The correlation shapes, for trigger particles and various associated particle PT ranges within, are consistent with Gaussians, and their widths increase with centrality. The results indicate jet broadening in the medium created in central heavy-ion collisions.
Published: 2020

14. Beam-energy dependence of the directed flow of deuterons in Au+Au collisions

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: We present a measurement of the first-order azimuthal anisotropy v1 of deuterons from Au+Au collisions at sNN=7.7, 11.5, 14.5, 19.6, 27, and 39 GeV recorded with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The energy dependence of the v1(y) slope, dv1/dy|y=0, for deuterons, where y is the rapidity, is extracted for semicentral collisions (10%-40% centrality) and compared with that of protons. While the v1(y) slopes of protons are generally negative for sNN>10GeV, those for deuterons are consistent with zero, a strong enhancement of the v1(y) slope of deuterons is seen at the lowest collision energy (the largest baryon density) at sNN=7.7GeV. In addition, we report the transverse momentum dependence of v1 for protons and deuterons. The experimental results are compared with transport and coalescence models.
Published: 2020

15. Investigation of the linear and mode-coupled flow harmonics in Au+Au collisions at s N N = 200 GeV

Author: Collaboration, STAR, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, and Hu, Y
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Collectivity, Correlation, Shear viscosity, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: Flow harmonics (vn) of the Fourier expansion for the azimuthal distributions of hadrons are commonly employed to quantify the azimuthal anisotropy of particle production relative to the collision symmetry planes. While lower order Fourier coefficients (v2 and v3) are more directly related to the corresponding eccentricities of the initial state, the higher-order flow harmonics (vn>3) can be induced by a mode-coupled response to the lower-order anisotropies, in addition to a linear response to the same-order anisotropies. These higher-order flow harmonics and their linear and mode-coupled contributions can be used to more precisely constrain the initial conditions and the transport properties of the medium in theoretical models. The multiparticle azimuthal cumulant method is used to measure the linear and mode-coupled contributions in the higher-order anisotropic flow, the mode-coupled response coefficients, and the correlations of the event plane angles for charged particles as functions of centrality and transverse momentum in Au+Au collisions at nucleon-nucleon center-of-mass energy sNN= 200 GeV. The results are compared to similar LHC measurements as well as to several viscous hydrodynamic calculations with varying initial conditions.
Published: 2020

16. The formation times and building blocks of Milky Way-mass galaxies in the FIRE simulations

Author: Santistevan, Isaiah B, Wetzel, Andrew, El-Badry, Kareem, Bland-Hawthorn, Joss, Boylan-Kolchin, Michael, Bailin, Jeremy, Faucher-Giguère, Claude-André, and Benincasa, Samantha
Subjects: Astronomical Sciences, Physical Sciences, Stem Cell Research, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract: ABSTRACT: Surveys of the Milky Way (MW) and M31 enable detailed studies of stellar populations across ages and metallicities, with the goal of reconstructing formation histories across cosmic time. These surveys motivate key questions for galactic archaeology in a cosmological context: When did the main progenitor of an MW/M31-mass galaxy form, and what were the galactic building blocks that formed it? We investigate the formation times and progenitor galaxies of MW/M31-mass galaxies using the Feedback In Realistic Environments-2 cosmological simulations, including six isolated MW/M31-mass galaxies and six galaxies in Local Group (LG)-like pairs at z = 0. We examine main progenitor ‘formation’ based on two metrics: (1) transition from primarily ex-situ to in-situ stellar mass growth and (2) mass dominance compared to other progenitors. We find that the main progenitor of an MW/M31-mass galaxy emerged typically at z ∼ 3–4 ($11.6\!\!-\!\!12.2\, \rm {Gyr}$ ago), while stars in the bulge region (inner 2 kpc) at z = 0 formed primarily in a single main progenitor at z ≲ 5 (${\lesssim} \!12.6\, \rm {Gyr}$ ago). Compared with isolated hosts, the main progenitors of LG-like paired hosts emerged significantly earlier (Δz ∼ 2, $\Delta t\!\sim \!1.6\, \rm {Gyr}$), with ∼4× higher stellar mass at all z ≳ 4 (${\gtrsim} \!12.2\, \rm {Gyr}$ ago). This highlights the importance of environment in MW/M31-mass galaxy formation, especially at early times. On average, about 100 galaxies with $\rm {\it{ M}}_\rm {star}\!\gtrsim \!10^5\, \rm {M}_\odot$ went into building a typical MW/M31-mass system. Thus, surviving satellites represent a highly incomplete census (by ∼5×) of the progenitor population.
Published: 2020

17. Strange hadron production in Au+Au collisions at sNN=7.7, 11.5, 19.6, 27, and 39 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, and Huang, T
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: We present STAR measurements of strange hadron (KS0, Λ, Λ, Ξ-, Ξ+, ω-, ω+, and φ) production at midrapidity (|y|
Published: 2020

18. Beam energy dependence of net-Λ fluctuations measured by the STAR experiment at the BNL Relativistic Heavy Ion Collider

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, Huang, T, Huang, X, and Humanic, TJ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, hep-ph, nucl-th, Nuclear and plasma physics
Abstract: The measurements of particle multiplicity distributions have generated considerable interest in understanding the fluctuations of conserved quantum numbers in the quantum chromodynamics (QCD) hadronization regime, in particular near a possible critical point and near the chemical freeze-out. Net-protons and net-kaons have been used as proxies for the net-baryon number and net-strangeness, respectively. We report the measurement of efficiency- and centrality-bin width-corrected cumulant ratios (C2/C1, C3/C2) of net-Λ distributions, in the context of both strangeness and baryon number conservation, as a function of collision energy, centrality, and rapidity. The results are for Au+Au collisions at five beam energies (sNN=19.6, 27, 39, 62.4, and 200 GeV) recorded with the Solenoidal Tracker at RHIC (STAR). We compare our results to the Poisson and negative binomial (NBD) expectations, as well as to ultrarelativistic quantum molecular dynamics (UrQMD) and hadron resonance gas (HRG) model predictions. Both NBD and Poisson baselines agree with data within the statistical and systematic uncertainties. UrQMD describes the measured net-ΛC1 and C3 at 200 GeV reasonably well but deviates from C2, and the deviation increases as a function of collision energy. The ratios of the measured cumulants show no features of critical fluctuations. The chemical freeze-out temperatures extracted from a recent HRG calculation, which was successfully used to describe the net-proton, net-kaon, and net-charge data, indicate Λ freeze-out conditions similar to those of kaons. However, large deviations are found when comparing with temperatures obtained from net-proton fluctuations. The net-Λ cumulants show a weak but finite dependence on the rapidity coverage in the acceptance of the detector, which can be attributed to quantum number conservation.
Published: 2020

19. Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at s = 200 GeV with the STAR detector at RHIC

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harabasz, S, Harris, JW, He, S, He, W, He, XH, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, and Huang, HZ
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Diffraction, Forward physics, Hadron-Hadron scattering, hep-ex, nucl-ex, Mathematical Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Nuclear and plasma physics, Particle and high energy physics
Abstract: We report on the measurement of the Central Exclusive Production of charged particle pairs h+h− (h = π, K, p) with the STAR detector at RHIC in proton-proton collisions at s = 200 GeV. The charged particle pairs produced in the reaction pp → p′ + h+h− + p′ are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles’ transverse momenta and pseudorapidities as well as by the forward-scattered protons’ momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0.04 GeV2< −t1, −t2< 0.2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range |η| < 0.7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of π+π− and K+K− pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to π+π− production. For π+π− production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f0(980), f2(1270) and f0(1500), with a possible small contribution from the f0(1370). Fits to the extrapolated differential cross section as a function of t1 and t2 enable extraction of the exponential slope parameters in several bins of the invariant mass of π+π− pairs. These parameters are sensitive to the size of the interaction region. [Figure not available: see fulltext.].
Published: 2020

20. Measurement of D0-meson + hadron two-dimensional angular correlations in Au+Au collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: Open heavy-flavor hadrons provide unique probes of the medium produced in ultrarelativistic heavy-ion collisions. Due to their increased mass relative to light-flavor hadrons, long lifetime, and early production in hard-scattering interactions, they provide access to the full evolution of the partonic medium formed in heavy-ion collisions. This paper reports two-dimensional (2D) angular correlations between neutral D mesons and unidentified charged particles produced in minimum-bias Au+Au collisions at sNN=200GeV. D0 and D¯0 mesons are reconstructed via their weak decay to Kπ± using the Heavy Flavor Tracker in the Solenoidal Tracker at RHIC experiment. Correlations on relative pseudorapidity and azimuth (Δη,Δφ) are presented for peripheral, midcentral, and central collisions with D0 transverse momentum from 2-10GeV/c. Attention is focused on the 2D peaked correlation structure near the triggered D0 meson, the near-side (NS) peak, which serves as a proxy for a charm-quark-containing jet. The correlated NS yield of charged particles per D0 meson and the 2D widths of the NS peak increase significantly from peripheral to central collisions. These results are compared with similar correlations using unidentified charged particles, consisting primarily of light-flavor hadrons, at similar trigger particle momenta. Similar per-trigger yields and widths of the NS correlation peak are observed. The present results provide additional evidence that D0 mesons undergo significant interactions with the medium formed in heavy-ion collision and show, for the first time, significant centrality evolution of the NS 2D peak in the correlations of particles associated with a heavy-flavor hadron produced in these collisions.
Published: 2020

21. First Measurement of Λc Baryon Production in Au+Au Collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, Huang, SL, Huang, T, and Huang, X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, STAR Collaboration, nucl-ex, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We report on the first measurement of the charmed baryon Λ_{c}^{±} production at midrapidity (|y|
Published: 2020

22. Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, MC, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, Huang, SL, and Huang, T
Subjects: hep-ex, nucl-ex, nucl-th, Fluids & Plasmas, Mathematical Sciences, Physical Sciences
Abstract: According to the CPT theorem, which states that the combined operation of charge conjugation, parity transformation and time reversal must be conserved, particles and their antiparticles should have the same mass and lifetime but opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus containing a strange quark, more specifically in the hypertriton. This hypernucleus is the lightest one yet discovered and consists of a proton, a neutron and a Λ hyperon. With data recorded by the STAR detector1–3 at the Relativistic Heavy Ion Collider, we measure the Λ hyperon binding energy BΛ for the hypertriton, and find that it differs from the widely used value4 and from predictions5–8, where the hypertriton is treated as a weakly bound system. Our results place stringent constraints on the hyperon–nucleon interaction9,10 and have implications for understanding neutron star interiors, where strange matter may be present11. A precise comparison of the masses of the hypertriton and the antihypertriton allows us to test CPT symmetry in a nucleus with strangeness, and we observe no deviation from the expected exact symmetry.
Published: 2020

23. Underlying event measurements in p+p collisions at s=200 GeV at RHIC

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, Huang, SL, and Huang, T
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, nucl-ex, hep-ex
Abstract: Particle production sensitive to nonfactorizable and nonperturbative processes that contribute to the underlying event associated with a high transverse momentum (pT) jet in proton+proton collisions at s=200 GeV is studied with the STAR detector. Each event is divided into three regions based on the azimuthal angle with respect to the highest-pT jet direction: In the leading jet direction ("Toward"), opposite to the leading jet ("Away"), and perpendicular to the leading jet ("Transverse"). In the Transverse region, the average charged particle density is found to be between 0.4 and 0.6 and the mean transverse momentum,
Published: 2020

24. Bulk properties of the system formed in Au+Au collisions at sNN=14.5 GeV at the BNL STAR detector

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Chen, Z, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, S, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, HZ, Huang, SL, and Huang, T
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, hep-ph, Nuclear and plasma physics
Abstract: We report systematic measurements of bulk properties of the system created in Au+Au collisions at sNN=14.5 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The transverse momentum spectra of π±, K±, and p(p) are studied at midrapidity (|y|
Published: 2020

25. Beam-energy dependence of identified two-particle angular correlations in sNN=7.7–200 GeV Au+Au collisions

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chen, D, Chen, JH, Chen, X, Cheng, J, Cherney, M, Chevalier, M, Choudhury, S, Christie, W, Crawford, HJ, Csanád, M, Das, S, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, W, He, X, Heppelmann, S, Herrmann, N, Hoffman, E, Holub, L, Hong, Y, Horvat, S, Hu, Y, Huang, B, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: The two-particle angular correlation functions, $R_2$, of pions, kaons, andprotons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 14.5, 19.6, 27, 39,62.4, and 200 GeV were measured by the STAR experiment at RHIC. Thesecorrelations were measured for both like-sign and unlike-sign chargecombinations and versus the centrality. The correlations of pions and kaonsshow the expected near-side ({\it i.e.}, at small relative angles) peakresulting from short-range mechanisms. The amplitudes of these short-rangecorrelations decrease with increasing beam energy. However, the protoncorrelation functions exhibit strong anticorrelations in the near-side region.This behavior is observed for the first time in an A+A collision system. Theobserved anticorrelation is $p_{T}$-independent and decreases with increasingbeam energy and centrality. The experimental results are also compared to theMonte Carlo models UrQMD, Hijing, and AMPT.
Published: 2020

26. Landslides on Ceres: Diversity and Geologic Context

Author: Duarte, KD, Schmidt, BE, Chilton, HT, Hughson, KHG, Sizemore, HG, Ferrier, KL, Buffo, JJ, Scully, JEC, Nathues, A, Platz, T, Landis, M, Byrne, S, Bland, M, Russell, CT, and Raymond, CA
Subjects: Earth Sciences, Physical Sciences, Space Sciences, Geology, asteroids, ices, landslides, Ceres, Astronomical and Space Sciences, Geochemistry, Astronomical sciences
Abstract: Landslides are among the most widespread geologic features on Ceres. Using data from Dawn's Framing Camera, landslides were previously classified based upon geomorphologic characteristics into one of three archetypal categories, Type 1(T1), Type 2 (T2), and Type 3 (T3). Due to their geologic context, variation in age, and physical characteristics, most landslides on Ceres are, however, intermediate in their morphology and physical properties between the archetypes of each landslide class. Here we describe the varied morphology of individual intermediate landslides, identify geologic controls that contribute to this variation, and provide first-order quantification of the physical properties of the continuum of Ceres's surface flows. These intermediate flows appear in varied settings and show a range of characteristics, including those found at contacts between craters, those having multiple trunks or lobes; showing characteristics of both T2 and T3 landslides; material slumping on crater rims; very small, ejecta-like flows; and those appearing inside of catenae. We suggest that while their morphologies can vary, the distribution and mechanical properties of intermediate landslides do not differ significantly from that of archetypal landslides, confirming a link between landslides and subsurface ice. We also find that most intermediate landslides are similar to Type 2 landslides and formed by shallow failure. Clusters of these features suggest ice enhancement near Juling, Kupalo and Urvara craters. Since the majority of Ceres's landslides fall in the intermediate landslide category, placing their attributes in context contributes to a better understanding of Ceres's shallow subsurface and the nature of ground ice.
Published: 2019

27. Charge-dependent pair correlations relative to a third particle in p + Au and d + Au collisions at RHIC

Author: Collaboration, STAR, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, hep-ex, hep-ph, nucl-th, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: Quark interactions with topological gluon configurations can induce chirality imbalance and local parity violation in quantum chromodynamics. This can lead to electric charge separation along the strong magnetic field in relativistic heavy-ion collisions – the chiral magnetic effect (CME). We report measurements by the STAR collaboration of a CME-sensitive observable in p+Au and d+Au collisions at 200 GeV, where the CME is not expected, using charge-dependent pair correlations relative to a third particle. We observe strong charge-dependent correlations similar to those measured in heavy-ion collisions. This bears important implications for the interpretation of the heavy-ion data.
Published: 2019

28. First Observation of the Directed Flow of D0 and D0¯ in Au+Au Collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Greiner, L, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, STAR Collaboration, nucl-ex, hep-ex, nucl-th, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We report the first measurement of rapidity-odd directed flow (v_{1}) for D^{0} and D^{0}[over ¯] mesons at midrapidity (|y|
Published: 2019

29. Measurement of inclusive J/ψ suppression in Au+Au collisions at s NN = 200 GeV through the dimuon channel at STAR

Author: Collaboration, STAR, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, and Huang, SL
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Quark-gluon plasma, Color-screening, J/psi suppression, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: J/ψ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive J/ψ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at sNN=200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The J/ψ yields are measured in a wide transverse momentum (pT) range of 0.15 GeV/c to 12 GeV/c from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the J/ψ yield is suppressed by a factor of approximately 3 for pT>5 GeV/c relative to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The J/ψ nuclear modification factor displays little dependence on pT in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by J/ψ mesons in the QGP.
Published: 2019

30. First Observation of the Directed Flow of D^{0} and D^{0}[over ¯] in Au+Au Collisions at sqrt[s_{NN}]=200 GeV.

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Greiner, L, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, and Huang, SL
Subjects: STAR Collaboration, nucl-ex, hep-ex, nucl-th, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract: We report the first measurement of rapidity-odd directed flow (v_{1}) for D^{0} and D^{0}[over ¯] mesons at midrapidity (|y|
Published: 2019

31. Observation of Excess J/ψ Yield at Very Low Transverse Momenta in Au+Au Collisions at sNN=200 GeV and U+U Collisions at sNN=193 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, Sánchez, M Calderón de la Barca, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, Huang, T, and Huang, X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, STAR Collaboration, hep-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We report on the first measurements of J/ψ production at very low transverse momentum (p_{T}
Published: 2019

32. Polarization of Λ (Λ¯) Hyperons along the Beam Direction in Au+Au Collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, and Huang, T
Subjects: Nuclear and Plasma Physics, Physical Sciences, STAR Collaboration, nucl-ex, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: The Λ (Λ[over ¯]) hyperon polarization along the beam direction has been measured in Au+Au collisions at sqrt[s_{NN}]=200 GeV, for the first time in heavy-ion collisions. The polarization dependence on the hyperons' emission angle relative to the elliptic flow plane exhibits a second harmonic sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction, expected due to elliptic flow. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum (p_{T}) dependence at p_{T} greater than 1 GeV/c. The magnitude of the signal is about 5 times smaller than those predicted by hydrodynamic and multiphase transport models; the observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, the kinematic vorticity calculations in the blast-wave model tuned to reproduce particle spectra, elliptic flow, and the azimuthal dependence of the Gaussian source radii measured with the Hanbury Brown-Twiss intensity interferometry technique reproduce well the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the polarization signal.
Published: 2019

33. Measurements of the transverse-momentum-dependent cross sections of J/ψ production at mid-rapidity in proton+proton collisions at s=510 and 500 GeV with the STAR detector

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, Huang, T, and Huang, X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, hep-ex, nucl-ex
Abstract: We present measurements of the differential cross sections of inclusive J/ψ meson production as a function of transverse momentum (pTJ/ψ) using the μ+μ- and e+e- decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the μ+μ- channel is for 0
Published: 2019

34. Longitudinal double-spin asymmetry for inclusive jet and dijet production in pp collisions at s=510 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, and Huang, T
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Mathematical Physics, Mathematical Sciences, Physical Sciences, hep-ex, nucl-ex
Abstract: We report the first measurement of the inclusive jet and the dijet longitudinal double-spin asymmetries, ALL, at midrapidity in polarized pp collisions at a center-of-mass energy s=510 GeV. The inclusive jet ALL measurement is sensitive to the gluon helicity distribution down to a gluon momentum fraction of x≈0.015, while the dijet measurements, separated into four jet-pair topologies, provide constraints on the x dependence of the gluon polarization. Both results are consistent with previous measurements made at s=200 GeV in the overlapping kinematic region, x>0.05, and show good agreement with predictions from recent next-to-leading order global analyses.
Published: 2019

35. Polarization of Λ (Λ[over ¯]) Hyperons along the Beam Direction in Au+Au Collisions at sqrt[s_{NN}]=200 GeV.

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Gopal, K, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, and Huang, T
Subjects: STAR Collaboration, nucl-ex, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract: The Λ (Λ[over ¯]) hyperon polarization along the beam direction has been measured in Au+Au collisions at sqrt[s_{NN}]=200 GeV, for the first time in heavy-ion collisions. The polarization dependence on the hyperons' emission angle relative to the elliptic flow plane exhibits a second harmonic sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction, expected due to elliptic flow. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum (p_{T}) dependence at p_{T} greater than 1 GeV/c. The magnitude of the signal is about 5 times smaller than those predicted by hydrodynamic and multiphase transport models; the observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, the kinematic vorticity calculations in the blast-wave model tuned to reproduce particle spectra, elliptic flow, and the azimuthal dependence of the Gaussian source radii measured with the Hanbury Brown-Twiss intensity interferometry technique reproduce well the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the polarization signal.
Published: 2019

36. Collision-energy dependence of second-order off-diagonal and diagonal cumulants of net-charge, net-proton, and net-kaon multiplicity distributions in Au + Au collisions

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, Huang, T, and Huang, X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, hep-ph, Nuclear and plasma physics
Abstract: We report the first measurements of a complete second-order cumulant matrix of net-charge, net-proton, and net-kaon multiplicity distributions for the first phase of the beam energy scan program at the Relativistic Heavy Ion Collider. This includes the centrality and, for the first time, the pseudorapidity window dependence of both diagonal and off-diagonal cumulants in Au+Au collisions at sNN= 7.7-200 GeV. Within the available acceptance of |η|
Published: 2019

37. Beam energy dependence of (anti-)deuteron production in Au + Au collisions at the BNL Relativistic Heavy Ion Collider

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Crawford, HJ, Csanád, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, Hong, Y, Horvat, S, Huang, B, Huang, HZ, Huang, SL, Huang, T, and Huang, X
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, nucl-th, Nuclear and plasma physics
Abstract: We report the energy dependence of mid-rapidity (anti-)deuteron production in Au+Au collisions at sNN=7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by the STAR experiment at the BNL Relativistic Heavy Ion Collider. The yield of deuterons is found to be well described by the thermal model. The collision energy, centrality, and transverse momentum dependence of the coalescence parameter B2 are discussed. We find that the values of B2 for antideuterons are systematically lower than those for deuterons, indicating that the correlation volume of antibaryons is larger than that of baryons at sNN from 19.6 to 39 GeV. In addition, values of B2 are found to vary with collision energy and show a broad minimum around sNN=20-40 GeV, which might imply a change of the equation of state of the medium in these collisions.
Published: 2019

38. Azimuthal Harmonics in Small and Large Collision Systems at RHIC Top Energies

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, and Herrmann, N
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, STAR Collaboration, nucl-ex, nucl-th, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: The first (v_{1}^{fluc}), second (v_{2}), and third (v_{3}) harmonic coefficients of the azimuthal particle distribution at midrapidity are extracted for charged hadrons and studied as a function of transverse momentum (p_{T}) and mean charged particle multiplicity density ⟨N_{ch}⟩ in U+U (sqrt[s_{NN}]=193 GeV), Au+Au, Cu+Au, Cu+Cu, d+Au, and p+Au collisions at sqrt[s_{NN}]=200 GeV with the STAR detector. For the same ⟨N_{ch}⟩, the v_{1}^{fluc} and v_{3} coefficients are observed to be independent of the collision system, while v_{2} exhibits such a scaling only when normalized by the initial-state eccentricity (ϵ_{2}). The data also show that ln(v_{2}/ϵ_{2}) scales linearly with ⟨N_{ch}⟩^{-1/3}. These measurements provide insight into initial-geometry fluctuations and the role of viscous hydrodynamic attenuation on v_{n} from small to large collision systems.
Published: 2019

39. Collision-energy dependence of pt correlations in Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Hirsch, A, Holub, L, and Hong, Y
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: We present two-particle pt correlations as a function of event centrality for Au+Au collisions at sNN=7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These results are compared to previous measurements from CERES at the Super Proton Synchrotron and from ALICE at the Large Hadron Collider. The data are compared with UrQMD model calculations and with a model based on a Boltzmann-Langevin approach incorporating effects from thermalization. The relative dynamical correlations for Au+Au collisions at sNN=200 GeV show a power-law dependence on the number of participant nucleons and agree with the results for Pb+Pb collisions at sNN=2.76TeV from ALICE. As the collision energy is lowered from sNN=200 to 7.7 GeV, the centrality dependence of the relative dynamical correlations departs from the power-law behavior observed at the higher collision energies. In central collisions, the relative dynamical correlations increase with collision energy up to sNN=200 GeV in contrast to previous measurements that showed little dependence on the collision energy.
Published: 2019

40. Search for Higgs-like particles produced in association with bottom quarks in proton-antiproton collisions

Author: Aaltonen, T, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, JA, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, VE, Barnett, BA, Barria, P, Bartos, P, Bauce, M, Bedeschi, F, Behari, S, Bellettini, G, Bellinger, J, Benjamin, D, Beretvas, A, Bhatti, A, Bland, KR, Blumenfeld, B, Bocci, A, Bodek, A, Bortoletto, D, Boudreau, J, Boveia, A, Brigliadori, L, Bromberg, C, Brucken, E, Budagov, J, Budd, HS, Burkett, K, Busetto, G, Bussey, P, Butti, P, Buzatu, A, Calamba, A, Camarda, S, Campanelli, M, Canelli, F, Carls, B, Carlsmith, D, Carosi, R, Carrillo, S, Casal, B, Casarsa, M, Castro, A, Catastini, P, Cauz, D, Cavaliere, V, Cerri, A, Cerrito, L, Chen, YC, Chertok, M, Chiarelli, G, Chlachidze, G, Cho, K, Chokheli, D, Clark, A, Clarke, C, Convery, ME, Conway, J, Corbo, M, Cordelli, M, Cox, CA, Cox, DJ, Cremonesi, M, Cruz, D, Cuevas, J, Culbertson, R, d’Ascenzo, N, Datta, M, de Barbaro, P, Demortier, L, Deninno, M, D’Errico, M, Devoto, F, Di Canto, A, Di Ruzza, B, Dittmann, JR, Donati, S, D’Onofrio, M, Dorigo, M, Driutti, A, Ebina, K, Edgar, R, Elagin, A, Erbacher, R, and Errede, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract: We report on a search for a spin-zero non-standard model particle in proton-antiproton collisions collected by the Collider Detector at Fermilab at a center-of-mass-energy of 1.96 TeV. This particle, the φ boson, is expected to decay into a bottom-antibottom quark pair and to be produced in association with at least one bottom quark. The data sample consists of events with three jets identified as initiated by bottom quarks and corresponds to 5.4 fb-1 of integrated luminosity. In each event, the invariant mass of the two most energetic jets is studied by looking for deviations from the multijet background, which is modeled using data. No evidence is found for such a particle. Exclusion upper limits ranging from 20 to 2 pb are set for the product of production cross sections times branching fraction for the hypothetical φ boson with mass between 100 and 300 GeV/c2. These are the most stringent constraints to date.
Published: 2019

41. Centrality and transverse momentum dependence of D0-meson production at mid-rapidity in Au + Au collisions at sNN=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, and Hirsch, A
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, Nuclear and plasma physics
Abstract: We report a new measurement of D0-meson production at mid-rapidity (|y|4GeV/c in central 0-10% Au + Au collisions. At low pT, the nuclear modification factors show a characteristic structure qualitatively consistent with the expectation from model predictions that charm quarks gain sizable collective motion during the medium evolution. The improved measurements are expected to offer new constraints to model calculations and help gain further insights into the hot and dense medium created in these collisions.
Published: 2019

42. Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at s=510 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Edmonds, T, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, Herrmann, N, Holub, L, and Hong, Y
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex
Abstract: We report new STAR measurements of the single-spin asymmetries AL for W+ and W- bosons produced in polarized proton-proton collisions at s=510 GeV as a function of the decay-positron and decay-electron pseudorapidity. The data were obtained in 2013 and correspond to an integrated luminosity of 250 pb-1. The results are combined with previous results obtained with 86 pb-1. A comparison with theoretical expectations based on polarized lepton-nucleon deep-inelastic scattering and prior polarized proton-proton data suggests a difference between the ū and d quark helicity distributions for 0.05
Published: 2019

43. Constraining the initial conditions and temperature dependent viscosity with three-particle correlations in Au+Au collisions

Author: Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Ajitanand, NN, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Bouchet, J, Brandenburg, JD, Brandin, AV, Brown, D, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Campbell, JM, Cebra, D, Chakaberia, I, Chaloupka, P, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, X, Chen, JH, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Das, S, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Draper, JE, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Feng, Z, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Garand, D, Geurts, F, Gibson, A, Girard, M, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, and Heppelmann, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, nucl-th, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: We present three-particle mixed-harmonic correlations 〈cos⁡(mϕa+nϕb−(m+n)ϕc)〉 for harmonics m,n=1−3 for charged particles in sNN=200 GeV Au+Au collisions at RHIC. These measurements provide information on the three-dimensional structure of the initial collision zone and are important for constraining models of a subsequent low-viscosity quark–gluon plasma expansion phase. We investigate correlations between the first, second and third harmonics predicted as a consequence of fluctuations in the initial state. The dependence of the correlations on the pseudorapidity separation between particles show hints of a breaking of longitudinal invariance. We compare our results to a number of state-of-the art hydrodynamic calculations with different initial states and temperature dependent viscosities. These measurements provide important steps towards constraining the temperature dependent viscosity and longitudinal structure of the initial state at RHIC.
Published: 2019

44. The proton–Ω correlation function in Au + Au collisions at s NN = 200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Ajitanand, NN, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Campbell, JM, Cebra, D, Chakaberia, I, Chaloupka, P, Chang, Z, Chang, F-H, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, and Herrmann, N
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Correlations, Femtoscopy, N Omega dibaryon, hep-ex, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: We present the first measurement of the proton–Ω correlation function in heavy-ion collisions for the central (0–40%) and peripheral (40–80%) Au + Au collisions at s NN =200 GeV by the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). Predictions for the ratio of peripheral collisions to central collisions for the proton–Ω correlation function are sensitive to the presence of a nucleon–Ω bound state. These predictions are based on the proton–Ω interaction extracted from (2+1)-flavor lattice QCD calculations at the physical point. The measured ratio of the proton–Ω correlation function between the peripheral (small system) and central (large system) collisions is less than unity for relative momentum smaller than 40 MeV/c. Comparison of our measured correlation ratio with theoretical calculation slightly favors a proton–Ω bound system with a binding energy of ∼ 27 MeV.
Published: 2019

45. The NASA Roadmap to Ocean Worlds

Author: Hendrix, Amanda R, Hurford, Terry A, Barge, Laura M, Bland, Michael T, Bowman, Jeff S, Brinckerhoff, William, Buratti, Bonnie J, Cable, Morgan L, Castillo-Rogez, Julie, Collins, Geoffrey C, Diniega, Serina, German, Christopher R, Hayes, Alexander G, Hoehler, Tori, Hosseini, Sona, Howett, Carly JA, McEwen, Alfred S, Neish, Catherine D, Neveu, Marc, Nordheim, Tom A, Patterson, G Wesley, Patthoff, D Alex, Phillips, Cynthia, Rhoden, Alyssa, Schmidt, Britney E, Singer, Kelsi N, Soderblom, Jason M, and Vance, Steven D
Subjects: Astronomical Sciences, Physical Sciences, Life Below Water, Exobiology, Oceans and Seas, Planets, United States, United States National Aeronautics and Space Administration, Roadmap, Enceladus, Titan, Europa, Triton, NASA, NASA., Astronomical and Space Sciences, Geochemistry, Geology, Astronomy & Astrophysics, Astronomical sciences
Abstract: In this article, we summarize the work of the NASA Outer Planets Assessment Group (OPAG) Roadmaps to Ocean Worlds (ROW) group. The aim of this group is to assemble the scientific framework that will guide the exploration of ocean worlds, and to identify and prioritize science objectives for ocean worlds over the next several decades. The overarching goal of an Ocean Worlds exploration program as defined by ROW is to "identify ocean worlds, characterize their oceans, evaluate their habitability, search for life, and ultimately understand any life we find." The ROW team supports the creation of an exploration program that studies the full spectrum of ocean worlds, that is, not just the exploration of known ocean worlds such as Europa but candidate ocean worlds such as Triton as well. The ROW team finds that the confirmed ocean worlds Enceladus, Titan, and Europa are the highest priority bodies to target in the near term to address ROW goals. Triton is the highest priority candidate ocean world to target in the near term. A major finding of this study is that, to map out a coherent Ocean Worlds Program, significant input is required from studies here on Earth; rigorous Research and Analysis studies are called for to enable some future ocean worlds missions to be thoughtfully planned and undertaken. A second finding is that progress needs to be made in the area of collaborations between Earth ocean scientists and extraterrestrial ocean scientists.
Published: 2019

46. Improved measurement of the longitudinal spin transfer to Λ and Λ¯ hyperons in polarized proton-proton collisions at s=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deng, J, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, and Heppelmann, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex
Abstract: The longitudinal spin transfer DLL to Λ and Λ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of s=200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η|
Published: 2018

47. Transverse spin transfer to Λ and Λ¯ hyperons in polarized proton-proton collisions at s=200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Csanad, M, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, and Herrmann, N
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex
Abstract: The transverse spin transfer from polarized protons to Λ and Λ hyperons is expected to provide sensitivity to the transversity distribution of the nucleon and to the transversely polarized fragmentation functions. We report the first measurement of the transverse spin transfer to Λ and Λ along the polarization direction of the fragmenting quark, DTT, in transversely polarized proton-proton collisions at s=200 GeV with the STAR detector at RHIC. The data correspond to an integrated luminosity of 18 pb-1 and cover the pseudorapidity range |η|
Published: 2018

48. J/ψ production cross section and its dependence on charged-particle multiplicity in p + p collisions at s = 200 GeV

Author: Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Ajitanand, NN, Alekseev, I, Anderson, DM, Aoyama, R, Aparin, A, Arkhipkin, D, Aschenauer, EC, Ashraf, MU, Atetalla, F, Attri, A, Averichev, GS, Bai, X, Bairathi, V, Barish, K, Bassill, AJ, Behera, A, Bellwied, R, Bhasin, A, Bhati, AK, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Brown, D, Bryslawskyj, J, Bunzarov, I, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Campbell, JM, Cebra, D, Chakaberia, I, Chaloupka, P, Chang, F-H, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, JH, Chen, X, Cheng, J, Cherney, M, Christie, W, Contin, G, Crawford, HJ, Das, S, Dedovich, TG, Deppner, IM, Derevschikov, AA, Didenko, L, Dilks, C, Dong, X, Drachenberg, JL, Dunlop, JC, Efimov, LG, Elsey, N, Engelage, J, Eppley, G, Esha, R, Esumi, S, Evdokimov, O, Ewigleben, J, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Federicova, P, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Gibson, A, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Harlenderova, A, Harris, JW, He, L, Heppelmann, S, and Herrmann, N
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Quarkonium, p plus p collisions, Multiple parton interactions, Charged-particle multiplicity, hep-ex, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: We present a measurement of inclusive J/ψ production at mid-rapidity (|y|
Published: 2018

49. Where are the most ancient stars in the Milky Way?

Author: El-Badry, Kareem, Bland-Hawthorn, Joss, Wetzel, Andrew, Quataert, Eliot, Weisz, Daniel R, Boylan-Kolchin, Michael, Hopkins, Philip F, Faucher-Giguère, Claude-André, Kereš, Dušan, and Garrison-Kimmel, Shea
Subjects: Astronomical Sciences, Physical Sciences, Galaxy: evolution, Galaxy: formation, Galaxy: stellar content, Galaxy, evolution - Galaxy, formation - Galaxy, stellar content, astro-ph.GA, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Particle and high energy physics, Space sciences
Abstract: The oldest stars in the Milky Way (MW) bear imprints of the Galaxy's early assembly history. We use FIRE cosmological zoom-in simulations of three MW-mass disc galaxies to study the spatial distribution, chemistry, and kinematics of the oldest surviving stars (z form ≳ 5) in MW-like galaxies. We predict the oldest stars to be less centrally concentrated at z = 0 than stars formed at later times as a result of two processes. First, the majority of the oldest stars are not formed in situ but are accreted during hierarchical assembly. These ex situ stars are deposited on dispersion-supported, halo-like orbits but dominate over old stars formed in situ in the solar neighbourhood, and in some simulations, even in the galactic centre. Secondly, old stars formed in situ are driven outwards by bursty star formation and energetic feedback processes that create a time-varying gravitational potential at z ≳ 2, similar to the process that creates dark matter cores and expands stellar orbits in bursty dwarf galaxies. The total fraction of stars that are ancient is more than an order of magnitude higher for sight lines away from the bulge and inner halo than for inward-looking sight lines. Although the task of identifying specific stars as ancient remains challenging, we anticipate that million-star spectral surveys and photometric surveys targeting metal-poor stars already include hundreds of stars formed before z = 5. We predict most of these targets to have higher metallicity (-3 < [Fe/H] < -2) than the most extreme metal-poor stars.
Published: 2018

50. Search for standard-model Z and Higgs bosons decaying into a bottom-antibottom quark pair in proton-antiproton collisions at 1.96 TeV

Author: Aaltonen, T, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, JA, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, VE, Barnett, BA, Barria, P, Bartos, P, Bauce, M, Bedeschi, F, Behari, S, Bellettini, G, Bellinger, J, Benjamin, D, Beretvas, A, Bhatti, A, Bland, KR, Blumenfeld, B, Bocci, A, Bodek, A, Bortoletto, D, Boudreau, J, Boveia, A, Brigliadori, L, Bromberg, C, Brucken, E, Budagov, J, Budd, HS, Burkett, K, Busetto, G, Bussey, P, Butti, P, Buzatu, A, Calamba, A, Camarda, S, Campanelli, M, Canelli, F, Carls, B, Carlsmith, D, Carosi, R, Carrillo, S, Casal, B, Casarsa, M, Castro, A, Catastini, P, Cauz, D, Cavaliere, V, Cerri, A, Cerrito, L, Chen, YC, Chertok, M, Chiarelli, G, Chlachidze, G, Cho, K, Chokheli, D, Clark, A, Clarke, C, Convery, ME, Conway, J, Corbo, M, Cordelli, M, Cox, CA, Cox, DJ, Cremonesi, M, Cruz, D, Cuevas, J, Culbertson, R, d’Ascenzo, N, Datta, M, de Barbaro, P, Demortier, L, Deninno, M, D’Errico, M, Devoto, F, Di Canto, A, Di Ruzza, B, Dittmann, JR, Donati, S, D’Onofrio, M, Dorigo, M, Driutti, A, Ebina, K, Edgar, R, Elagin, A, Erbacher, R, and Errede, S
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract: The Collider Detector at Fermilab collected a unique sample of jets originating from bottom-quark fragmentation (b-jets) by selecting online proton-antiproton (pp̄) collisions with a vertex displaced from the pp̄ interaction point, consistent with the decay of a bottom-quark hadron. This data set, collected at a center-of-mass energy of 1.96 TeV, and corresponding to an integrated luminosity of 5.4 fb-1, is used to measure the Z-boson production cross section times branching ratio into bb̄. The number of Z→bb̄ events is determined by fitting the dijet-mass distribution, while constraining the dominant b-jet background, originating from QCD multijet events, with data. The result, σ(pp̄→Z)×B(Z→bb̄)=1.11±0.08(stat)±0.14(syst) nb, is the most precise measurement of this process, and is consistent with the standard-model prediction. The data set is also used to search for Higgs-boson production. No significant signal is expected in our data and the first upper limit on the cross section for the inclusive pp̄→H→bb̄ process at s=1.96 TeV is set, corresponding to 33 times the expected standard-model cross section, or σ=40.6 pb, at the 95% confidence level.
Published: 2018

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