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201. Measurement of charge multiplicity asymmetry correlations in high-energy nucleus-nucleus collisions at sNN =200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Alford, J, Anson, CD, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Cai, XZ, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derradi De Souza, R, Dhamija, S, Didenko, L, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, E, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Gliske, S, Gorbunov, YN, Grebenyuk, OG, and Grosnick, D

Subjects
nucl-ex, nucl-th, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at sNN=200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, Δ, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic v2obs), where Δ=[1.3±1.4(stat)-1.0+4.0(syst)]×10- 5+[3.2±0.2(stat)-0.3+0.4(syst)]×10-3v2obs for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed. © 2014 American Physical Society.

Published
2014

202. Event-plane-dependent dihadron correlations with harmonic vn subtraction in Au + Au collisions at s NN =200 GeV

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, MC, 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, AD, De Silva, LC, Debbe, RR, Dedovich, TG, Derevschikov, AA, De Souza, RD, 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
nucl-ex, nucl-th, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

STAR measurements of dihadron azimuthal correlations (Δφ) are reported in midcentral (20-60%) Au+Au collisions at sNN=200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, φs=|φt-ψEP|. The elliptic (v2), triangular (v3), and quadratic (v4) flow harmonic backgrounds are subtracted using the zero yield at minimum (ZYAM) method. The results are compared to minimum-bias d+Au collisions. It is found that a finite near-side (|Δφ|π/2) correlation shows a modification from d+Au data, varying with φs. The modification may be a consequence of path-length-dependent jet quenching and may lead to a better understanding of high-density QCD. © 2014 American Physical Society.

Published
2014

203. Event-plane-dependent dihadron correlations with harmonic vn subtraction in Au + Au collisions at sNN=200 GeV

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
nucl-ex, nucl-th, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

STAR measurements of dihadron azimuthal correlations (Δφ) are reported in midcentral (20-60%) Au+Au collisions at sNN=200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, φs=|φt-ψEP|. The elliptic (v2), triangular (v3), and quadratic (v4) flow harmonic backgrounds are subtracted using the zero yield at minimum (ZYAM) method. The results are compared to minimum-bias d+Au collisions. It is found that a finite near-side (|Δφ|π/2) correlation shows a modification from d+Au data, varying with φs. The modification may be a consequence of path-length-dependent jet quenching and may lead to a better understanding of high-density QCD. © 2014 American Physical Society.

Published
2014

204. Measurement of charge multiplicity asymmetry correlations in high-energy nucleus-nucleus collisions at sNN=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Alford, J, Anson, CD, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Cai, XZ, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, de Souza, R Derradi, Dhamija, S, Didenko, L, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, E, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Gliske, S, Gorbunov, YN, Grebenyuk, OG, and Grosnick, D

Subjects
nucl-ex, nucl-th, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at sNN=200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, Δ, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic v2obs), where Δ=[1.3±1.4(stat)-1.0+4.0(syst)]×10- 5+[3.2±0.2(stat)-0.3+0.4(syst)]×10-3v2obs for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed. © 2014 American Physical Society.

Published
2014

205. Jet-Hadron Correlations in sNN=200 GeV p+p and Central Au+Au Collisions

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
STAR Collaboration, nucl-ex, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

Published
2014

206. Jet-hadron correlations in √[s(NN)]=200  GeV p+p and central Au+Au collisions.

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
STAR Collaboration, nucl-ex, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

Published
2014

207. Energy Dependence of Moments of Net-Proton Multiplicity Distributions at RHIC

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Grosnick, D, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
STAR Collaboration, nucl-ex, hep-ex, hep-lat, hep-ph, nucl-th, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

We report the beam energy (sqrt[sNN]=7.7-200  GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|

Published
2014

208. Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at s = 200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barber, B, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Bridgeman, A, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, and Grosnick, D

Subjects
nucl-ex, hep-ex, Nuclear & Particles Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8

Published
2014

209. Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at s=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barber, B, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Bridgeman, A, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, and Grosnick, D

Subjects
nucl-ex, hep-ex, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8

Published
2014

210. Fluctuations of charge separation perpendicular to the event plane and local parity violation in s NN = 200 GeV Au + Au collisions at the BNL Relativistic Heavy Ion Collider

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, AD, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, De Souza, RD, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, and Gliske, S

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Previous experimental results based on data (∼15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion. © 2013 American Physical Society.

Published
2013

211. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sNN=200 GeV Au + Au collisions at the BNL Relativistic Heavy Ion Collider

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, and Gliske, S

Subjects
Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

Previous experimental results based on data (∼15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion. © 2013 American Physical Society.

Published
2013

212. Freeze-out dynamics via charged kaon femtoscopy in √s NN=200 GeV central Au + Au collisions

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, and Gliske, S

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We present measurements of three-dimensional correlation functions of like-sign, low-transverse-momentum kaon pairs from √sNN=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event-generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass mT over the interval of 0.55≤mT≤1.15 GeV/c2. While the kaon radii are adequately described by the mT -scaling in the outward and sideward directions, in the longitudinal direction the lowest mT value exceeds the expectations from a pure hydrodynamical model prediction. © 2013 American Physical Society.

Published
2013

213. Freeze-out dynamics via charged kaon femtoscopy in sNN=200 GeV central Au + Au collisions

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, and Gliske, S

Subjects
nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

We present measurements of three-dimensional correlation functions of like-sign, low-transverse-momentum kaon pairs from √sNN=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event-generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass mT over the interval of 0.55≤mT≤1.15 GeV/c2. While the kaon radii are adequately described by the mT -scaling in the outward and sideward directions, in the longitudinal direction the lowest mT value exceeds the expectations from a pure hydrodynamical model prediction. © 2013 American Physical Society.

Published
2013

214. Measurement of J/ψ Azimuthal Anisotropy in Au+Au Collisions at sNN=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Cai, XZ, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, E, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Gliske, S, and Grebenyuk, OG

Subjects
Anisotropy, Elementary Particles, Gold, Quantum Theory, STAR Collaboration, nucl-ex, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Published
2013

215. Elliptic flow of identified hadrons in Au+Au collisions at √s NN=7.7-62.4 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Cai, XZ, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, E, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Gliske, S, and Grebenyuk, OG

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Measurements of the elliptic flow, v2, of identified hadrons (π±, K±, Ks0, p, p̄, φ, Λ, Λ̄, Ξ-, Ξ̄+, Ω-, Ω̄+) in Au+Au collisions at √sNN=7.7, 11.5, 19.6, 27, 39, and 62.4 GeV are presented. The measurements were done at midrapidity using the time-projection chamber and the time-of-flight detectors of the Solenoidal Tracker at RHIC experiment during the beam-energy scan program at Relativistic Heavy Ion Collider. A significant difference in the v2 values for particles and the corresponding antiparticles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, √s NN (or increasing baryon chemical potential, μB), and is larger for the baryons as compared to the mesons. This implies that particles and antiparticles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of v2 that was observed at √sNN=200 GeV. However, for the selected group of particles (π+, K+, Ks0, p, Λ, Ξ-, Ω-) NCQ scaling at (mT-m0)/n q>0.4 GeV/c2 is not violated within ±10%. The v2 values for φ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured pT values. © 2013 American Physical Society.

Published
2013

216. Elliptic flow of identified hadrons in Au+Au collisions at sNN=7.7–62.4 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Cai, XZ, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, E, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Gliske, S, and Grebenyuk, OG

Subjects
nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

Measurements of the elliptic flow, v2, of identified hadrons (π±, K±, Ks0, p, p̄, φ, Λ, Λ̄, Ξ-, Ξ̄+, Ω-, Ω̄+) in Au+Au collisions at √sNN=7.7, 11.5, 19.6, 27, 39, and 62.4 GeV are presented. The measurements were done at midrapidity using the time-projection chamber and the time-of-flight detectors of the Solenoidal Tracker at RHIC experiment during the beam-energy scan program at Relativistic Heavy Ion Collider. A significant difference in the v2 values for particles and the corresponding antiparticles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, √s NN (or increasing baryon chemical potential, μB), and is larger for the baryons as compared to the mesons. This implies that particles and antiparticles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of v2 that was observed at √sNN=200 GeV. However, for the selected group of particles (π+, K+, Ks0, p, Λ, Ξ-, Ω-) NCQ scaling at (mT-m0)/n q>0.4 GeV/c2 is not violated within ±10%. The v2 values for φ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured pT values. © 2013 American Physical Society.

Published
2013

217. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

Author

Collaboration, STAR, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, E, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bhattarai, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bruna, E, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Sánchez, M Calderón de la Barca, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chung, P, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, Silva, LC De, Debbe, RR, Dedovich, TG, Deng, J, Souza, R Derradi de, Dhamija, S, Ruzza, B di, Didenko, L, Dilks, Ding, F, Dion, A, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, and Gibson, A

Subjects
nucl-ex
Abstract

Previous experimental results based on data (15 million events) collected bythe STAR detector at RHIC suggest event-by-event charge separation fluctuationsperpendicular to the event plane in non-central heavy-ion collisions. Here wepresent the correlator previously used split into its two component parts toreveal correlations parallel and perpendicular to the event plane. The resultsare from a high statistics 200 GeV Au+Au collisions data set (57 millionevents) collected by the STAR experiment. We explicitly count units of chargeseparation from which we find clear evidence for more charge separationfluctuations perpendicular than parallel to the event plane. We also employ amodified correlator to study the possible P-even background in same andopposite charge correlations, and find that the P-even background may largelybe explained by momentum conservation and collective motion.

Published
2013

218. An Experimental Exploration of the QCD Phase Diagram: The Search for the Critical Point and the Onset of De-confinement

Author

Collaboration, STAR, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Anderson, BD, Arkhipkin, D, Averichev, GS, Balewski, J, Barnby, LS, Baumgart, S, Beavis, DR, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Biritz, B, Bland, LC, Bonner, BE, Bouchet, J, Braidot, E, Brandin, AV, Bridgeman, A, Bruna, E, Bueltmann, S, Bunzarov, I, Burton, TP, Cai, XZ, Caines, H, CalderóndelaBarcaSánchez, M, Catu, O, Cebra, D, Cendejas, R, Cervantes, MC, Chajecki, Z, Chaloupka, P, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Cheng, J, Cherney, M, Chikanian, A, Choi, KE, Christie, W, Chung, P, Clarke, RF, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Das, D, Dash, S, DavilaLeyva, A, DeSilva, LC, Debbe, RR, Dedovich, TG, Derevschikov, AA, DerradideSouza, R, Didenko, L, Djawotho, P, Dogra, SM, Dong, X, Drachenberg, JL, Draper, JE, Dunlop, JC, DuttaMazumdar, MR, Efimov, LG, Elhalhuli, E, Elnimr, M, Engelage, J, Eppley, G, Erazmus, B, Estienne, M, Eun, L, Evdokimov, O, Fachini, P, Fatemi, R, Fedorisin, J, Fersch, RG, Filip, P, Finch, E, Fine, V, Fisyak, Y, Gagliardi, CA, Gangadharan, DR, Ganti, MS, Garcia, EJ, Solis, Geromitsos, A, Geurts, F, Ghazikhanian, V, Ghosh, P, Gorbunov, YN, Gordon, A, and Grebenyuk, O

Subjects
nucl-ex
Abstract

The QCD phase diagram lies at the heart of what the RHIC Physics Program isall about. While RHIC has been operating very successfully at or close to itsmaximum energy for almost a decade, it has become clear that this collider canalso be operated at lower energies down to 5 GeV without extensive upgrades. Anexploration of the full region of beam energies available at the RHIC facilityis imperative. The STAR detector, due to its large uniform acceptance andexcellent particle identification capabilities, is uniquely positioned to carryout this program in depth and detail. The first exploratory beam energy scan(BES) run at RHIC took place in 2010 (Run 10), since several STAR upgrades,most importantly a full barrel Time of Flight detector, are now completed whichadd new capabilities important for the interesting physics at BES energies. Inthis document we discuss current proposed measurements, with estimations of theaccuracy of the measurements given an assumed event count at each beam energy.

Published
2010

219. Hadronic resonance production in d+Au collisions at sNN=200 GeV measured at the BNL Relativistic Heavy Ion Collider

Author

Abelev, BI, Aggarwal, MM, Ahammed, Z, Anderson, BD, Arkhipkin, D, Averichev, GS, Bai, Y, Balewski, J, Barannikova, O, Barnby, LS, Baudot, J, Baumgart, S, Beavis, DR, Bellwied, R, Benedosso, F, Betts, RR, Bhardwaj, S, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Biritz, B, Bland, LC, Bombara, M, Bonner, BE, Botje, M, Bouchet, J, Braidot, E, Brandin, AV, Bruna, Bueltmann, S, Burton, TP, Bystersky, M, Cai, XZ, Caines, H, De La Barca Sánchez, MC, Callner, J, Catu, O, Cebra, D, Cendejas, R, Cervantes, MC, Chajecki, Z, Chaloupka, P, Chattopdhyay, S, Chen, HF, Chen, JH, Chen, JY, Cheng, J, Cherney, M, Chikanian, A, Choi, KE, Christie, W, Chung, SU, Clarke, RF, Codrington, MJM, Coffin, JP, Cormier, TM, Cosentino, MR, Cramer, JG, Crawford, HJ, Das, D, Dash, S, Daugherity, M, De Silva, C, Dedovich, TG, Dephillips, M, Derevschikov, AA, De Souza, RD, Didenko, L, Djawotho, P, Dogra, SM, Dong, X, Drachenberg, JL, Draper, JE, Du, F, Dunlop, JC, Mazumdar, MRD, Edwards, WR, Efimov, LG, Elhalhuli, E, Elnimr, M, Emelianov, V, Engelage, J, Eppley, G, Erazmus, B, Estienne, M, Eun, L, Fachini, P, Fatemi, R, Fedorisin, J, Feng, A, Filip, P, Finch, E, Fine, V, Fisyak, Y, Gagliardi, CA, Gaillard, L, Gangaharan, DR, and Ganti, MS

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We present the first measurements of the ρ(770)0,K*(892), Δ(1232)++,Σ(1385), and Λ(1520) resonances in d+Au collisions at sNN=200 GeV, reconstructed via their hadronic decay channels using the STAR detector (the solenoidal tracker at the BNL Relativistic Heavy Ion Collider). The masses and widths of these resonances are studied as a function of transverse momentum pT. We observe that the resonance spectra follow a generalized scaling law with the transverse mass mT. The pT of resonances in minimum bias collisions are compared with the pT of π,K, and p̄. The ρ0/π-,K*/K-,Δ++/p,Σ(1385)/Λ, and Λ(1520)/Λ ratios in d+Au collisions are compared with the measurements in minimum bias p+p interactions, where we observe that both measurements are comparable. The nuclear modification factors (RdAu) of the ρ0,K*, and Σ* scale with the number of binary collisions (Nbin) for pT 1.2 GeV/c. © 2008 The American Physical Society.

Published
2008

220. Neutral kaon interferometry in Au+Au collisions at sNN=200 GeV

Author

Abelev, BI, Aggarwal, MM, Ahammed, Z, Amonett, J, Anderson, BD, Anderson, M, Arkhipkin, D, Averichev, GS, Bai, Y, Balewski, J, Barannikova, O, Barnby, LS, Baudot, J, Bekele, S, Belaga, VV, Bellingeri-Laurikainen, A, Bellwied, R, Benedosso, F, Bhardwaj, S, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Blyth, SL, Bonner, BE, Botje, M, Bouchet, J, Brandin, AV, Bravar, A, Burton, TP, Bystersky, M, Cadman, RV, Cai, XZ, Caines, H, Sánchez, MCDLB, Castillo, J, Catu, O, Cebra, D, Chajecki, Z, Chaloupka, P, Chattopadhyay, S, Chen, HF, Chen, JH, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Coffin, JP, Cormier, TM, Cosentino, MR, Cramer, JG, Crawford, HJ, Das, D, Das, S, Dash, S, Daugherity, M, Moura, MMD, Dedovich, TG, Dephillips, M, Derevschikov, AA, Didenko, L, Dietel, T, Djawotho, P, Dogra, SM, Dong, WJ, Dong, X, Draper, JE, Du, F, Dunin, VB, Dunlop, JC, Mazumdar, MRD, Eckardt, V, Edwards, WR, Efimov, LG, Emelianov, V, Engelage, J, Eppley, G, Erazmus, B, Estienne, M, Fachini, P, Fatemi, R, Fedorisin, J, Filimonov, K, Filip, P, Finch, E, Fine, V, Fisyak, Y, Fu, J, Gagliardi, CA, Gaillard, L, Ganti, MS, Ghazikhanian, V, Ghosh, P, Gonzalez, JE, Gorbunov, YG, Gos, H, Grebenyuk, O, and Grosnick, D

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We present the first statistically meaningful results from two-Ks0 interferometry in heavy-ion collisions at sNN=200 GeV. A model that takes the effect of the strong interaction into account has been used to fit the measured correlation function. The effects of single and coupled channels were explored. At the mean transverse mass mT =1.07 GeV, we obtain the values R=4.09±0.46(stat)±0.31(sys) fm and λ=0.92±0.23(stat) ±0.13(sys), where R and λ are the invariant radius and chaoticity parameters, respectively. The results are qualitatively consistent with mT systematics established with pions in a scenario characterized by a strong collective flow. © 2006 The American Physical Society.

Published
2006

221. Future of low-x forward physics at RHIC

Author

Bland, LC, Bieser, F, Brown, RL, Crawford, HJ, Derevshchikov, AA, Drachenberg, JL, Engelage, J, Eun, L, Gagliardi, CA, Heppelmann, S, Judd, EG, Kravtsov, VI, Matulenko, Yu A, Meschanin, AP, Morozov, DA, Nogach, LV, Nurushev, SB, Ogawa, A, Perkins, C, Rakness, G, Shestermanov, KE, and Vasiliev, AN

Subjects
hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics
Abstract

Comparisons of particle production from high-energy ion collisions with next-to-leading order perturbative QCD calculations show good agreement down to moderate transverse momentum values. Distributions of azimuthal angle differences between coincident hadrons in these collisions support a partonic origin to the particle production again down to moderate transverse momentum values. The rapidity dependence of inclusive and coincident particle production can therefore be used to probe parton distribution functions down to small momentum fractions where theory anticipates that parton saturation could be present. This paper describes how such experiments could be completed. © Springer-Verlag 2005.

Published
2005

222. Longitudinal double-spin asymmetry for inclusive jet and dijet production in polarized proton collisions at s =510 GeV

Author

Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bunzarov, I, Cai, XZ, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bunzarov, I, Cai, XZ, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, and Hamed, A

Abstract

We report measurements of the longitudinal double-spin asymmetry, ALL, for inclusive jet and dijet production in polarized proton-proton collisions at midrapidity and center-of-mass energy s=510 GeV, using the high luminosity data sample collected by the STAR experiment in 2013. These measurements complement and improve the precision of previous STAR measurements at the same center-of-mass energy that probe the polarized gluon distribution function at partonic momentum fraction 0.015≲x≲0.25. The dijet asymmetries are separated into four jet-pair topologies, which provide further constraints on the x dependence of the polarized gluon distribution function. These measurements are in agreement with previous STAR measurements and with predictions from current next-to-leading-order global analyses. They provide more precise data at low dijet invariant mass that will better constrain the shape of the polarized gluon distribution function of the proton.

Published
2022

223. Light nuclei collectivity from sNN=3 GeV Au+Au collisions at RHIC

Author

Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Aitbaev, A, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Cai, XZ, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Feng, CJ, Feng, Y, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamed, A, Han, Y, Harabasz, S, Harasty, MD, Harris, JW, Harrison, H, He, S, He, W, He, XH, He, Y, Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Aitbaev, A, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Cai, XZ, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Feng, CJ, Feng, Y, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamed, A, Han, Y, Harabasz, S, Harasty, MD, Harris, JW, Harrison, H, He, S, He, W, He, XH, and He, Y

Abstract

In high-energy heavy-ion collisions, partonic collectivity is evidenced by the constituent quark number scaling of elliptic flow anisotropy for identified hadrons. A breaking of this scaling and dominance of baryonic interactions is found for identified hadron collective flow measurements in sNN = 3 GeV Au+Au collisions. In this paper, we report measurements of the first- and second-order azimuthal anisotropic parameters, v1 and v2, of light nuclei (d, t, 3He, 4He) produced in sNN = 3 GeV Au+Au collisions at the STAR experiment. An atomic mass number scaling is found in the measured v1 slopes of light nuclei at mid-rapidity. For the measured v2 magnitude, a strong rapidity dependence is observed. Unlike v2 at higher collision energies, the v2 values at mid-rapidity for all light nuclei are negative and no scaling is observed with the atomic mass number. Calculations by the Jet AA Microscopic Transport Model (JAM), with baryonic mean-field plus nucleon coalescence, are in good agreement with our observations, implying baryonic interactions dominate the collective dynamics in 3 GeV Au+Au collisions at RHIC.

Published
2022

224. Search for the chiral magnetic effect with isobar collisions at

Author

Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bunzarov, I, Cai, XZ, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, Hamed, A, Abdallah, MS, Abdallah, MS, Aboona, BE, Adam, J, Adamczyk, L, Adams, JR, Adkins, JK, Agakishiev, G, Aggarwal, I, Aggarwal, MM, Ahammed, Z, Alekseev, I, Anderson, DM, Aparin, A, Aschenauer, EC, Ashraf, MU, Atetalla, FG, Attri, A, Averichev, GS, Bairathi, V, Baker, W, Ball Cap, JG, Barish, K, Behera, A, Bellwied, R, Bhagat, P, Bhasin, A, Bielcik, J, Bielcikova, J, Bordyuzhin, IG, Brandenburg, JD, Brandin, AV, Bunzarov, I, Cai, XZ, Caines, H, Calderón de la Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, Chang, Z, Chankova-Bunzarova, N, Chatterjee, A, Chattopadhyay, S, Chen, D, Chen, J, Chen, JH, Chen, X, Chen, Z, Cheng, J, Chevalier, M, Choudhury, S, Christie, W, Chu, X, Crawford, HJ, Csanád, M, Daugherity, M, Dedovich, TG, Deppner, IM, Derevschikov, AA, Dhamija, A, Di Carlo, L, Didenko, L, Dixit, P, Dong, X, Drachenberg, JL, Duckworth, E, Dunlop, JC, Elsey, N, Engelage, J, Eppley, G, Esumi, S, Evdokimov, O, Ewigleben, A, Eyser, O, Fatemi, R, Fawzi, FM, Fazio, S, Federic, P, Fedorisin, J, Feng, CJ, Feng, Y, Filip, P, Finch, E, Fisyak, Y, Francisco, A, Fu, C, Fulek, L, Gagliardi, CA, Galatyuk, T, Geurts, F, Ghimire, N, Gibson, A, Gopal, K, Gou, X, Grosnick, D, Gupta, A, Guryn, W, Hamad, AI, and Hamed, A

Abstract

The chiral magnetic effect (CME) is predicted to occur as a consequence of a local violation of P and CP symmetries of the strong interaction amidst a strong electromagnetic field generated in relativistic heavy-ion collisions. Experimental manifestation of the CME involves a separation of positively and negatively charged hadrons along the direction of the magnetic field. Previous measurements of the CME-sensitive charge-separation observables remain inconclusive because of large background contributions. To better control the influence of signal and backgrounds, the STAR Collaboration performed a blind analysis of a large data sample of approximately 3.8 billion isobar collisions of Ru4496+Ru4496 and Zr4096+Zr4096 at sNN=200 GeV. Prior to the blind analysis, the CME signatures are predefined as a significant excess of the CME-sensitive observables in Ru+Ru collisions over those in Zr+Zr collisions, owing to a larger magnetic field in the former. A precision down to 0.4% is achieved, as anticipated, in the relative magnitudes of the pertinent observables between the two isobar systems. Observed differences in the multiplicity and flow harmonics at the matching centrality indicate that the magnitude of the CME background is different between the two species. No CME signature that satisfies the predefined criteria has been observed in isobar collisions in this blind analysis.

Published
2022

225. 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
Quantum Physics, Particle and Plasma Physics, hep-ex, Molecular, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, Atomic, Nuclear & Particles Physics, Astronomical and Space Sciences
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

226. 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
Particle and Plasma Physics, nucl-th, anisotropic flow background, Molecular, Nuclear, event plane, Nuclear Experiment, dihadron correlations, nucl-ex, jet-medium interactions, Atomic, Nuclear & Particles Physics, relativistic heavy ion collisions
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

227. 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
Quality Education, di-hadron correlations, Particle and Plasma Physics, jet, heavy-ion, Molecular, Nuclear, nucl-ex, Atomic, Nuclear & Particles 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

228. First Measurement of Λ_{c} Baryon Production 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, 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, 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
STAR Collaboration, General Physics, Engineering, hep-ex, Physical Sciences, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment, nucl-ex, Mathematical Sciences
Abstract

We report on the first measurement of the charmed baryon Λ_{c}^{±} production at midrapidity (|y

Published
2020

229. 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
nucl-th, hep-ex, Fluids & Plasmas, High Energy Physics::Phenomenology, Nuclear Theory, Physical Sciences, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, Mathematical 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

230. 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, Calderón De La Barca Sánchez, M, 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
Quantum Physics, Particle and Plasma Physics, hep-ex, Astrophysics::High Energy Astrophysical Phenomena, Molecular, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles Physics, Astronomical and Space Sciences
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

231. 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
Particle and Plasma Physics, hep-ex, Molecular, Nuclear, High Energy Physics::Experiment, hep-ph, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles 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

232. Beam-energy dependence of identified two-particle angular correlations ins root s(NN)=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, Sanchez, M Calderon de la Barca, 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, Csanad, 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, Huang, SL, and Huang, T

Subjects
Nuclear Theory, Nuclear Experiment, nucl-ex
Abstract

The two-particle angular correlation functions, $R_2$, of pions, kaons, and protons 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. These correlations were measured for both like-sign and unlike-sign charge combinations and versus the centrality. The correlations of pions and kaons show the expected near-side ({\it i.e.}, at small relative angles) peak resulting from short-range mechanisms. The amplitudes of these short-range correlations decrease with increasing beam energy. However, the proton correlation functions exhibit strong anticorrelations in the near-side region. This behavior is observed for the first time in an A+A collision system. The observed anticorrelation is $p_{T}$-independent and decreases with increasing beam energy and centrality. The experimental results are also compared to the Monte Carlo models UrQMD, Hijing, and AMPT.

Published
2020

233. 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
Particle and Plasma Physics, Nuclear Theory, Molecular, Nuclear, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles Physics
Abstract

The two-particle angular correlation functions, $R_2$, of pions, kaons, and protons 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. These correlations were measured for both like-sign and unlike-sign charge combinations and versus the centrality. The correlations of pions and kaons show the expected near-side ({\it i.e.}, at small relative angles) peak resulting from short-range mechanisms. The amplitudes of these short-range correlations decrease with increasing beam energy. However, the proton correlation functions exhibit strong anticorrelations in the near-side region. This behavior is observed for the first time in an A+A collision system. The observed anticorrelation is $p_{T}$-independent and decreases with increasing beam energy and centrality. The experimental results are also compared to the Monte Carlo models UrQMD, Hijing, and AMPT.

Published
2020

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

Author

Adam, J, 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, 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, Huang, T, Adam, J, 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, 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

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

235. Measurement of away-side broadening with self-subtraction of flow in Au+Au collisions at √sNN = 200 GeV

Author

Adam, J, 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, 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, Huang, SL, Adam, J, 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, 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

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

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

Author

Adam, J, 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, 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, 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, Huang, SL, Adam, J, 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, 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, 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

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

237. Investigation of the linear and mode-coupled flow harmonics in Au+Au collisions at sNN = 200 GeV

Author

Adam, J, 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, 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, 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, Huang, HZ, Huang, SL, Adam, J, 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, 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, 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, Huang, HZ, and Huang, SL

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

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

Author

Adam, J, 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, 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, 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, Huang, HZ, Huang, SL, Adam, J, 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, 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, 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, Huang, HZ, and Huang, SL

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

240. The STAR beam energy scan phase II physics and upgrades

Author

YANG, C, ADAMCZYK, L, ADKINS, JK, AGAKISHIEV, G, AGGARWAL, MM, AHAMMED, Z, ALEKSEEV, I, APARIN, A, ARKHIPKIN, D, ASCHENAUER, EC, ASHRAF, MU, ATTRI, A, AVERICHEV, GS, BAI, X, BAIRATHI, V, BELLWIED, R, BHASIN, A, BHATI, AK, BHATTARAI, P, BIELCIK, J, BIELCIKOVA, J, BLAND, LC, BORDYUZHIN, IG, BOUCHET, J, BRANDENBURG, JD, BRANDIN, AV, BUNZAROV, I, BUTTERWORTH, J, CAINES, H, SANCHEZ, MCDL, CAMPBELL, JM, CEBRA, D, CHAKABERIA, I, CHALOUPKA, P, CHANG, Z, 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, DI RUZZA, B, DIDENKO, L, DILKS, C, DONG, X, DRACHENBERG, JL, DRAPER, JE, DU, CM, DUNKELBERGER, LE, DUNLOP, JC, EFIMOV, LG, ENGELAGE, J, EPPLEY, G, ESHA, R, EVDOKIMOV, O, EYSER, O, FATEMI, R, FAZIO, S, FEDERIC, P, FEDORISIN, J, FENG, Z, FILIP, P, FISYAK, Y, FLORES, CE, FULEK, L, GAGLIARDI, CA, GARAND, D, GEURTS, F, GIBSON, A, GIRARD, M, GREINER, L, GROSNICK, D, GUNARATHNE, DS, GUO, Y, GUPTA, S, GUPTA, A, GURYN, W, HAMAD, AI, HAMED, A, HAGUE, R, HARRIS, JW, HE, L, HEPPELMANN, S, HIRSCH, A, HOFFMANN, GW, HORVAT, S, HUANG, T, HUANG, B, HUANG, X, HUANG, HZ, HUCK, P, HUMANIC, TJ, IGO, G, JACOBS, WW, JANG, H, JENTSCH, A, JIA, J, JIANG, K, JUDD, EG, KABANA, S, KALINLDN, D, KANG, K, KAUDER, K, KE, HW, KEANE, D, KECHECHYAN, A, KHAN, ZH, KIKOLA, DP, KISEL, I, KISIEL, A, KOCHENDA, L, KOETKE, DD, KOSARZEWSKI, LK, KRAISHAN, AF, KRAVTSOV, P, KRUEGER, K, KUMAR, L, LAMONT, MAC, LANDGRAF, JM, LANDRY, KD, LAURET, J, LEBEDEV, A, LEDNICKY, R, LEE, JH, LI, X, LI, Y, LI, C, LI, W, LIN, T, LISA, MA, LIU, F, LJUBICIC, T, LLOPE, WJ, LOMNITZ, M, LONGACRE, RS, LUO, X, LUO, S, MA, GL, MA, L, ME, YG, MA, R, MAGDY, N, MAJKA, R, MANION, A, MARGETIS, S, MARKERT, C, MATIS, HS, MCDONALD, D, MCKINZIE, S, MEEHAN, K, MEI, JC, MILLER, ZW, MINAEV, NG, MIODUSZEWSKI, S, MISHRA, D, MOHANTY, B, MONDAL, MM, MOROZOV, DA, MUSTAFA, MK, NANDI, BK, NASIM, M, NAYAK, TK, NIGMATKULOV, G, NIIDA, T, NOGACH, LV, NOH, SY, NOVAK, J, NURUSHEV, SB, ODYNIEC, G, OGAWA, A, OH, K, OKOROKOV, VA, OLVITT, D, PAGE, BS, PAK, R, PAN, YX, PANDIT, Y, PANEBRATSEV, Y, PAWLIK, B, PEI, H, PERKINS, C, PILE, P, PLUTA, J, PONIATOWSKA, K, PORTER, J, POSIK, M, POSKANZER, AM, PRUTHI, NK, PRZYBYCIEN, M, PUTSCHKE, J, QIU, H, QUINTERO, A, RAMACHANDRAN, S, RAY, RL, REED, R, RITTER, HG, ROBERTS, JB, ROGACHEVSKIY, OV, ROMERO, JL, RUAN, L, RUSNAK, J, RUSNAKOVA, O, SAHOO, NR, SAHU, PK, SAKREJDA, I, SALUR, S, SANDWEISS, J, SARKAR, A, SCHAMBACH, J, SCHARENBERG, RP, SCHMAH, AM, SCHMIDKE, WB, SCHMITZ, N, SEGER, J, SEYBOTH, P, SHAH, N, SHAHALIEV, E, SHANMUGANATHAN, PV, SHAO, M, SHARMA, A, SHARMA, B, SHARMA, MK, SHEN, WQ, SHI, Z, SHI, SS, SHOU, QY, SICHTERMANN, EP, SIKORA, R, SIMKO, M, SINGHA, S, SKOBY, MJ, SMIRNOV, D, SMIRNOV, N, SOLYST, W, SONG, L, SORENSEN, P, SPINKA, HM, SRIVASTAVA, B, STANISLAUS, TDS, STEPANOV, M, STOCK, R, STRIKHANOV, M, STRINGFELLOW, B, SUMBERA, M, SUMMA, B, SUN, Y, SUN, Z, SUN, XM, SURROW, B, SVIRIDA, DN, TANG, Z, TANG, AH, TARNOWSKY, T, TAWFIK, A, THADER, J, THOMAS, JH, TIMMINS, AR, TLUSTY, D, TODOROKI, T, TOKAREV, M, TRENTALANGE, S, TRIBBLE, RE, TRIBEDY, P, TRIPATHY, SK, TSAI, OD, ULLRICH, T, UNDERWOOD, DG, UPSAL, I, VAN BUREN, G, VAN NIEUWENHUIZEN, G, VANDENBROUCKE, M, VARMA, R, VASILIEV, AN, VERTESI, R, VIDEAEK, F, VOKAL, S, VOLOSHIN, SA, VOSSEN, A, WANG, H, WANG, F, WANG, Y, WANG, JS, WANG, G, WEBB, JC, WEBB, G, WEN, L, WESTFALL, GD, WIEMAN, H, WISSINK, SW, WITT, R, WU, Y, XIAO, ZG, XIE, W, XIE, G, XIN, K, XU, N, XU, QH, XU, Z, XU, J, XU, H, XU, YF, YANG, S, YANG, Y, YANG, Q, YE, Z, YI, L, YIP, K, YOO, IK, YU, N, ZBROSZCZYK, H, ZHA, W, ZHANG, Z, ZHANG, JB, ZHANG, S, ZHANG, XP, ZHANG, Y, ZHANG, J, ZHAO, J, ZHONG, C, ZHOU, L, ZHU, X, ZOULKARNEEVA, Y, and ZYZAK, M

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Qcd phase diagram, Detector, 01 natural sciences, law.invention, Nuclear physics, Upgrade, law, Critical point (thermodynamics), Baryon density, 0103 physical sciences, Detector Upgrade, High Energy Physics::Experiment, Physics Opportunity, Nuclear Experiment, 010306 general physics, Bes-Ii, Qcd Phase Diagram, Beam energy, Order of magnitude, Electron cooling
Abstract

The second phase of the Beam Energy Scan at RHIC, BPS-II, is scheduled for 2019-2020 and will explore with precision measurements the high baryon density region of the QCD phase diagram. The program will examine the energy region of interest determined from the results of BES-I. Some of the key measurements anticipated are: the net-protons kurtosis that could pinpoint the position of a critical point, the directed flow that might prove a softening of the EOS, and the chiral restoration in the dilepton channel. The measurements will be possible with the order of magnitude better statistics provided by the electron cooling upgrade of RHIC and with the detector upgrades planned to extend STAR's experimental reach. The upgrades are: the inner TPC sectors (iTPC), the Event Plane Detector (EPD), and the end -cap TOF (eTOF). We present the BES-II program details and the physics opportunities enabled by these upgrades.

Published
2017

241. 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
nucl-th, hep-ex, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Molecular, hep-ph, nucl-ex, Nuclear & Particles Physics, Atomic, Particle and Plasma Physics, Nuclear, Nuclear Experiment, Mathematical Physics, Astronomical and Space 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

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

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, FH, 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, Huang, T, and Huang, X

Subjects
J/psi suppression, Nuclear Theory, Quark-gluon plasma, Molecular, Color-screening, nucl-ex, Nuclear & Particles Physics, Atomic, Particle and Plasma Physics, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, Mathematical Physics, Astronomical and Space 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

243. 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
J/psi suppression, Nuclear Theory, Quark-gluon plasma, Molecular, Color-screening, nucl-ex, Atomic, Nuclear & Particles Physics, Particle and Plasma Physics, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, Mathematical Physics, Astronomical and Space 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

244. 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, General Physics, Engineering, nucl-th, hep-ex, Physical Sciences, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, Mathematical 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

245. 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
Quantum Physics, Particle and Plasma Physics, hep-ex, Molecular, Nuclear, High Energy Physics::Experiment, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles Physics, Astronomical and Space Sciences
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

246. 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, General Physics, Engineering, Physical Sciences, Nuclear Experiment, nucl-ex, Mathematical 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

247. Observation of Excess J/ψ Yield at Very Low Transverse Momenta in Au+Au Collisions at sqrt[s_{NN}]=200 GeV and U+U Collisions at sqrt[s_{NN}]=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
STAR Collaboration, General Physics, Engineering, hep-ex, Physical Sciences, High Energy Physics::Experiment, Nuclear Experiment, Mathematical Sciences
Abstract

We report on the first measurements of J/ψ production at very low transverse momentum (p_{T}

Published
2019

248. 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, Calderón De La Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, 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
Quantum Physics, Particle and Plasma Physics, hep-ex, Nuclear Theory, Molecular, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles Physics, Astronomical and Space Sciences
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

249. 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, Calderón De La Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, 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
Particle and Plasma Physics, hep-ex, Nuclear Theory, Molecular, High Energy Physics::Experiment, hep-ph, Nuclear, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles 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

250. 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, Calderón De La Barca Sánchez, M, Cebra, D, Chakaberia, I, Chaloupka, P, Chan, BK, Chang, FH, 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
Particle and Plasma Physics, nucl-th, hep-ex, Nuclear Theory, Molecular, High Energy Physics::Experiment, Nuclear, Nuclear Experiment, nucl-ex, Atomic, Nuclear & Particles 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

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