1 MoreReceived 8 March 2023DOI:https://doi.org/10.1103/PhysRevC.107.049903©2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasParticle & resonance productionRelativistic heavy-ion collisionsNuclear Physics

Dihadron azimuthal correlations containing a high transverse momentum (p(T)) 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 root s(NN)= 200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, phi(s) = vertical bar phi(t) - psi(EP)vertical bar .The azimuthal correlation is studied as a function of both the trigger and associated particle p(T). 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 phi(s), with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity Delta(eta) correlation) appears to drop with increasing phi(s) 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 phi(s)-dependence of the ridge or the away-side double-peak structure. The dropping ridge with phi(s), could be attributed to a phi(s)-dependent elliptic anisotropy; however, the physics mechanism of the ridge remains an open question. Even with a phi(s)-dependent elliptic flow, the away-side correlation structure is robust. These results, with extensive systematic studies of the dihadron correlations as a function of phi(s), trigger and associated particle p(T), and the pseudo-rapidity range Delta(eta), should provide stringent inputs to help understand the underlying physics mechanisms of jet-medium interactions in high energy nuclear collisions.

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

L. Adamczyk, J. K. Adkins, G. Agakishiev, M.M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, H. Caines, M. Calderón de la Barca Sánchez, J. M. Campbell, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J. Chwastowski, M. J. M. Codrington, G. Contin, J. G. Cramer, H. J. Crawford, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, B. di Ruzza, L. Didenko, C. Dilks, F. Ding, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, J. Engelage, K. S. Engle, G. Eppley, L. Eun, O. Evdokimov, O. Eyser, R. Fatemi, S. Fazio, J. Fedorisin, P. Filip, Y. Fisyak, C. E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, M. Girard, S. Gliske, L. Greiner, D. Grosnick, D. S. Gunarathne, Y. Guo, A. Gupta, S. Gupta, W. Guryn, B. Haag, A. Hamed, L.-X. Han, R. Haque, J. W. Harris, S. Heppelmann, A. Hirsch, G.W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, X. Huang, P. Huck, T. J. Humanic, G. Igo, W.W. Jacobs, H. Jang, E. G. Judd, S. Kabana, D. Kalinkin, K. Kang, K. Kauder, H.W. Ke, D. Keane, A. Kechechyan, A. Kesich, Z. H. Khan, D. P. Kikola, I. Kisel, A. Kisiel, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. K. Kosarzewski, L. Kotchenda, A. F. Kraishan, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, R. A. Kycia, M. A. C. Lamont, J. M. Landgraf, K. D. Landry, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, C. Li, W. Li, X. Li, X. Li, Y. Li, Z. M. Li, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, M. Lomnitz, R. S. Longacre, X. Luo, G. L. Ma, Y. G. Ma, D. P. Mahapatra, R. Majka, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, N. G. Minaev, S. Mioduszewski, B. Mohanty, M.M. Mondal, D. A. Morozov, M. K. Mustafa, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, G. Nigmatkulov, L. V. Nogach, S. Y. Noh, J. Novak, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, D. L. Olvitt, Jr., B. S. Page, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, P. Pile, M. Planinic, J. Pluta, N. Poljak, K. Poniatowska, J. Porter, A. M. Poskanzer, N. K. Pruthi, M. Przybycien, J. Putschke, H. Qiu, A. Quintero, S. Ramachandran, R. Raniwala, S. Raniwala, R. L. Ray, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, A. Roy, L. Ruan, J. Rusnak, O. Rusnakova, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, W. B. Schmidke, N. Schmitz, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, P. V. Shanmuganathan, M. Shao, B. Sharma, W. Q. Shen, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, M. Simko, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, M. Sumbera, X. Sun, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, M. A. Szelezniak, J. Takahashi, A. H. Tang, Z. Tang, T. Tarnowsky, J. H. Thomas, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, M. Vandenbroucke, J. A. Vanfossen, Jr., R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, R. Vertesi, F. Videbæk, Y. P. Viyogi, S. Vokal, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, X. L. Wang, Y. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, H. Wieman, S. W. Wissink, R. Witt, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, J. Xu, N. Xu, Q. H. Xu, Y. Xu, Z. Xu, W. Yan, C. Yang, Y. Yang, Y. Yang, Z. Ye, P. Yepes, L. Yi, K. Yip, I.-K. Yoo, N. Yu, H. Zbroszczyk, W. Zha, J. B. Zhang, J. L. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak

The system created in non-central relativistic nucleus-nucleus collisions possesses large orbital angular momentum. Due to spin-orbit coupling, particles produced in such a system could become globally polarized along the direction of the system angular momentum. We present the results of Lambda and anti-Lambda hyperon global polarization measurements in Au+Au collisions at sqrts_NN=62.4 GeV and 200 GeV performed with the STAR detector at RHIC. The observed global polarization of Lambda and anti-Lambda hyperons in the STAR acceptance is consistent with zero within the precision of the measurements. The obtained upper limit, |P_Lambda,anti-Lambda| <= 0.02, is compared to the theoretical values discussed recently in the literature.

We present results of analyses of two-pion interferometry in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass ($m_{T}$) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.

Event-by-event fluctuations of the multiplicities of inclusive charged particles and photons at forward rapidity in Au + Au collisions at root s(NN) = 200 GeV have been studied. The dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidence of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as base lines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A nonzero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation owing to particle decay. Results are compared to the expectations based on the generic production mechanism of pions owing to isospin symmetry, for which no significant (<1%) deviation is observed.

L. Adamczyk, J. K. Adkins, G. Agakishiev, M.M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, S. Bültmann, I. Bunzarov, T. P. Burton, J. Butterworth, H. Caines, M. Calderón de la Barca Sánchez, J. M. Campbell, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J. Chwastowski, M. J. M. Codrington, G. Contin, J. G. Cramer, H. J. Crawford, A. B. Cudd, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, S. Dhamija, B. di Ruzza, L. Didenko, C. Dilks, F. Ding, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, J. Engelage, K. S. Engle, G. Eppley, L. Eun, O. Evdokimov, O. Eyser, R. Fatemi, S. Fazio, J. Fedorisin, P. Filip, E. Finch, Y. Fisyak, C. E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, M. Girard, S. Gliske, L. Greiner, D. Grosnick, D. S. Gunarathne, Y. Guo, A. Gupta, S. Gupta, W. Guryn, B. Haag, A. Hamed, L.-X. Han, R. Haque, J. W. Harris, S. Heppelmann, A. Hirsch, G.W. Hoffmann, D. J. Hofman, S. Horvat, B. Huang, H. Z. Huang, X. Huang, P. Huck, T. J. Humanic, G. Igo, W.W. Jacobs, H. Jang, E. G. Judd, S. Kabana, D. Kalinkin, K. Kang, K. Kauder, H.W. Ke, D. Keane, A. Kechechyan, A. Kesich, Z. H. Khan, D. P. Kikola, I. Kisel, A. Kisiel, D. D. Koetke, T. Kollegger, J. Konzer, I. Koralt, L. K. Kosarzewski, L. Kotchenda, A. F. Kraishan, P. Kravtsov, K. Krueger, I. Kulakov, L. Kumar, R. A. Kycia, M. A. C. Lamont, J. M. Landgraf, K. D. Landry, J. Lauret, A. Lebedev, R. Lednicky, J. H. Lee, M. J. LeVine, C. Li, W. Li, X. Li, X. Li, Y. Li, Z. M. Li, M. A. Lisa, F. Liu, T. Ljubicic, W. J. Llope, M. Lomnitz, R. S. Longacre, X. Luo, G. L. Ma, Y. G. Ma, D. M.M. D. Madagodagettige Don, D. P. Mahapatra, R. Majka, S. Margetis, C. Markert, H. Masui, H. S. Matis, D. McDonald, T. S. McShane, N. G. Minaev, S. Mioduszewski, B. Mohanty, M. M. Mondal, D. A. Morozov, M. K. Mustafa, B. K. Nandi, Md. Nasim, T. K. Nayak, J. M. Nelson, G. Nigmatkulov, L. V. Nogach, S. Y. Noh, J. Novak, S. B. Nurushev, G. Odyniec, A. Ogawa, K. Oh, A. Ohlson, V. Okorokov, E. W. Oldag, D. L. Olvitt, Jr., M. Pachr, B. S. Page, S. K. Pal, Y. X. Pan, Y. Pandit, Y. Panebratsev, T. Pawlak, B. Pawlik, H. Pei, C. Perkins, W. Peryt, P. Pile, M. Planinic, J. Pluta, N. Poljak, K. Poniatowska, J. Porter, A. M. Poskanzer, N. K. Pruthi, M. Przybycien, P. R. Pujahari, J. Putschke, H. Qiu, A. Quintero, S. Ramachandran, R. Raniwala, S. Raniwala, R. L. Ray, C. K. Riley, H. G. Ritter, J. B. Roberts, O. V. Rogachevskiy, J. L. Romero, J. F. Ross, A. Roy, L. Ruan, J. Rusnak, O. Rusnakova, N. R. Sahoo, P. K. Sahu, I. Sakrejda, S. Salur, J. Sandweiss, E. Sangaline, A. Sarkar, J. Schambach, R. P. Scharenberg, A. M. Schmah, W. B. Schmidke, N. Schmitz, J. Seger, P. Seyboth, N. Shah, E. Shahaliev, P. V. Shanmuganathan, M. Shao, B. Sharma, W. Q. Shen, S. S. Shi, Q. Y. Shou, E. P. Sichtermann, R. N. Singaraju, M. J. Skoby, D. Smirnov, N. Smirnov, D. Solanki, P. Sorensen, H. M. Spinka, B. Srivastava, T. D. S. Stanislaus, J. R. Stevens, R. Stock, M. Strikhanov, B. Stringfellow, M. Sumbera, X. Sun, X. M. Sun, Y. Sun, Z. Sun, B. Surrow, D. N. Svirida, T. J. M. Symons, M. A. Szelezniak, J. Takahashi, A. H. Tang, Z. Tang, T. Tarnowsky, J. H. Thomas, A. R. Timmins, D. Tlusty, M. Tokarev, S. Trentalange, R. E. Tribble, P. Tribedy, B. A. Trzeciak, O. D. Tsai, J. Turnau, T. Ullrich, D. G. Underwood, G. Van Buren, G. van Nieuwenhuizen, M. Vandenbroucke, J. A. Vanfossen, Jr., R. Varma, G. M. S. Vasconcelos, A. N. Vasiliev, R. Vertesi, F. Videbæk, Y. P. Viyogi, S. Vokal, A. Vossen, M. Wada, F. Wang, G. Wang, H. Wang, J. S. Wang, X. L. Wang, Y. Wang, Y. Wang, G. Webb, J. C. Webb, G. D. Westfall, H. Wieman, S. W. Wissink, R. Witt, Y. F. Wu, Z. Xiao, W. Xie, K. Xin, H. Xu, J. Xu, N. Xu, Q. H. Xu, Y. Xu, Z. Xu, W. Yan, C. Yang, Y. Yang, Y. Yang, Z. Ye, P. Yepes, L. Yi, K. Yip, I.-K. Yoo, N. Yu, Y. Zawisza, H. Zbroszczyk, W. Zha, J. B. Zhang, J. L. Zhang, S. Zhang, X. P. Zhang, Y. Zhang, Z. P. Zhang, F. Zhao, J. Zhao, C. Zhong, X. Zhu, Y. H. Zhu, Y. Zoulkarneeva, and M. Zyzak