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

Journal Article · Wed Aug 05 00:00:00 EDT 2020 · Physical Review. C

DOI:https://doi.org/10.1103/physrevc.102.024903· OSTI ID:1679972

Adam, J.; Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F. G.; Attri, A.; Averichev, G. S.; Bairathi, V.; Barish, K.; Bassill, A. J.; Behera, A. ; Bellwied, R. ; Bhasin, A.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A. V.; Bryslawskyj, J.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chan, B. K.; Chang, F-H; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Crawford, H. J.; Csanád, M.; Das, S.; Dedovich, T. G.; Deppner, I. M.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Dunlop, J. C.; Edmonds, T.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, A.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Y.; Filip, P.; Finch, E.; Fisyak, Y.; Fulek, L.; Gagliardi, C. A.; Galatyuk, T.; Geurts, F.; Gibson, A.; Gopal, K.; Grosnick, D.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Herrmann, N.; Holub, L.; Hong, Y.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, S. L.; Huang, T.; Huang, X.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jena, C.; Jentsch, A.; JI, Y.; Jia, J.; Jiang, K.; Jowzaee, S.; Ju, X.; Judd, E. G.; Kabana, S.; Kagamaster, S.; Kalinkin, D.; Kang, K.; Kapukchyan, D.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kelsey, M.; Khyzhniak, Y. V.; Kikoła, D. P.; Kim, C.; Kinghorn, T. A.; Kisel, I.; Kisiel, A.; Kocan, M.; Kochenda, L.; Kosarzewski, L. K.; Kramarik, L.; Kravtsov, P.; Krueger, K.; Kulathunga Mudiyanselage, N.; Kumar, L.; Kunnawalkam Elayavalli, R.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, W.; Li, X.; Li, Y.; Liang, Y.; Licenik, R.; Lin, T.; Lipiec, A.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, P.; Liu, P.; Liu, T.; Liu, X.; Liu, Y.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, R.; Ma, Y. G.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Matonoha, O.; Mazer, J. A.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Mooney, I.; Moravcova, Z.; Morozov, D. A.; Nasim, Md; Nayak, K.; Nelson, J. M.; Nemes, D. B.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Odyniec, G.; Ogawa, A.; Oh, S.; Okorokov, V. A.; Page, B. S.; Pak, R.; Panebratsev, Y.; Pawlik, B.; Pawlowska, D.; Pei, H.; Perkins, C.; Pintér, R. L.; Pluta, J.; Porter, J.; Posik, M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Quintero, A.; Radhakrishnan, S. K.; Ramachandran, S.; Ray, R. L.; Reed, R.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Schambach, J.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seck, F.; Seger, J.; Sergeeva, M.; Seto, R.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Shen, F.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Siejka, S.; Sikora, R.; Simko, M.; Singh, J.; Singha, S.; Smirnov, D.; Smirnov, N.; Solyst, W.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. S.; Stefaniak, M.; Stewart, D. J.; Strikhanov, M.; Stringfellow, B.; Suaide, A. P.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Y.; Sun, Y.; Surrow, B.; Svirida, D. N.; Szymanski, P.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Tomkiel, C. A.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Tu, B.; Tu, Z.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; Vanek, J.; Vasiliev, A. N.; Vassiliev, I.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Wang, F.; Wang, G.; Wang, P.; Wang, Y.; Wang, Y.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, G.; Xie, W.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, C.; Yang, Q.; Yang, S.; Yang, Y.; Yang, Z.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Zbroszczyk, H.; Zha, W.; Zhang, D.; Zhang, L.; Zhang, S.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z.; Zhao, J.; Zhong, C.; Zhou, C.; Zhu, X.; Zhu, Z.; Zurek, M.; Zyzak, M.

The measurements of particle multiplicity distributions have generated considerable interest in understanding the fluctuations of conserved quantum numbers in the quantum chromodynamics (QCD) hadronization regime, in particular near a possible critical point and near the chemical freeze-out. Net-protons and net-kaons have been used as proxies for the net-baryon number and net-strangeness, respectively. We report the measurement of efficiency- and centrality-bin width-corrected cumulant ratios (C₂/C₁, C₃/C₂) of net- Λ distributions, in the context of both strangeness and baryon number conservation, as a function of collision energy, centrality, and rapidity. The results are for Au + Au collisions at five beam energies ( √s_NN = 19.6 , 27, 39, 62.4, and 200 GeV) recorded with the Solenoidal Tracker at RHIC (STAR). We compare our results to the Poisson and negative binomial (NBD) expectations, as well as to ultrarelativistic quantum molecular dynamics (UrQMD) and hadron resonance gas (HRG) model predictions. Both NBD and Poisson baselines agree with data within the statistical and systematic uncertainties. UrQMD describes the measured net- Λ C₁ and C₃ at 200 GeV reasonably well but deviates from C₂, and the deviation increases as a function of collision energy. The ratios of the measured cumulants show no features of critical fluctuations. The chemical freeze-out temperatures extracted from a recent HRG calculation, which was successfully used to describe the net-proton, net-kaon, and net-charge data, indicate Λ freeze-out conditions similar to those of kaons. However, large deviations are found when comparing with temperatures obtained from net-proton fluctuations. The net- Λ cumulants show a weak but finite dependence on the rapidity coverage in the acceptance of the detector, which can be attributed to quantum number conservation.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Texas A & M Univ., College Station, TX (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Contributing Organization: STAR Collaboration
• Grant/Contract Number: SC0012704; AC02-05CH11231; SC0015636
• OSTI ID: 1679972
• Alternate ID(s): OSTI ID: 1713239; OSTI ID: 1787662
• Report Number(s): BNL-219984-2020-JAAM; TRN: US2204030
• Journal Information: Physical Review. C, Vol. 102, Issue 2; ISSN 2469-9985
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Particle correlations & fluctuations
quark-gluon plasma
relativistic heavy-ion collisions
thermal & statistical models