Underlying event measurements in $p+p$ collisions at $\sqrt{s}=200\mathrm{GeV}$ at RHIC

Journal Article · 10 March 2020 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.101.052004 · OSTI ID:1580259

Adam, J.; Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Anderson, D. M.; Aparin, A.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F. G.; Attri, A.; Averichev, G. S.; Bairathi, V.; Barish, K.; Behera, A.; Bellwied, R.; Bhasin, A. ; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A. V.; 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.; Chen, D.; Chen, J. H.; Chen, X.; Chen, Z.; Cheng, J.; Cherney, M.; Chevalier, M.; Choudhury, S.; Christie, W.; Crawford, H. J.; Csanád, M.; Daugherity, M.; Dedovich, T. G.; Deppner, I. M.; Derevschikov, A. A.; Didenko, L.; 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, C. J.; Feng, Y.; Filip, P.; Finch, E.; Fisyak, Y.; Francisco, A.; Fulek, L.; Gagliardi, C. A.; Galatyuk, T.; Geurts, F.; Gibson, A.; Gopal, K.; Grosnick, D.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harris, J. W.; He, S.; He, W.; He, X.; Heppelmann, S.; Heppelmann, S.; Herrmann, N.; Hoffman, E.; Holub, L.; Hong, Y.; Horvat, S.; Hu, Y.; Huang, H. Z.; Huang, S. L.; Huang, T.; Huang, X.; Humanic, T. J.; Huo, P.; Igo, G.; Isenhower, D.; Jacobs, W. W.; Jena, C.; Jentsch, A.; JI, Y.; Jia, J.; Jiang, K.; Jowzaee, S.; Ju, X.; Judd, E. G.; Kabana, S.; Kabir, M. L.; 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.; Kimelman, B.; Kincses, D.; Kinghorn, T. A.; Kisel, I.; Kiselev, A.; 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.; Lan, S.; Landgraf, J. M.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leung, Y. H.; Li, C.; Li, W.; Li, W.; Li, X.; Li, Y.; Liang, Y.; Licenik, R.; Lin, T.; Lin, Y.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, P.; Liu, P.; Liu, T.; Liu, X.; Liu, Y.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lukow, N. 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.; Mazer, J. A.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mooney, I.; Moravcova, Z.; Morozov, D. A.; Nagy, M.; Nam, J. D.; Nasim, Md.; Nayak, K.; Neff, D.; Nelson, J. M.; Nemes, D. B.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Odyniec, G.; Ogawa, A.; Oh, S.; Okorokov, V. A.; Page, B. S.; Pak, R.; Pandav, A.; Panebratsev, Y.; Pawlik, B.; Pawlowska, D.; Pei, H.; Perkins, C.; Pinsky, L.; Pintér, R. L.; Pluta, J.; Porter, J.; Posik, M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; 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.; Sahoo, N. R.; Sako, H.; Salur, S.; Sandweiss, J.; Sato, S.; 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.; Sikora, R.; Simko, M.; Singh, J.; Singha, S.; Smirnov, N.; Solyst, W.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stefaniak, M.; Stewart, D. J.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; 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, 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, J. S.; Wang, P.; Wang, Y.; Wang, Y.; Wang, Z.; Webb, J. C.; Weidenkaff, P. 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, Y.; Xu, Z.; 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, S.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Y.; Zhang, Z. J.; Zhang, Z.; Zhao, J.; Zhong, C.; Zhou, C.; Zhu, X.; Zhu, Z.; Zurek, M.; Zyzak, M.

In this work, particle production sensitive to non-factorizable and non-perturbative processes that contribute to the underlying event associated with a high transverse momentum (p_T) jet in proton+proton collisions at p √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-p_T jet direction: in the leading jet direction ("Toward"), opposite to the leading jet ("Away"), and perpendicular to the leading jet 3 ("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,$$\langle$$p_T$$\rangle$$, between 0.5-0.7 GeV/c for particles with p_T>0.2 GeV/c at mid-pseudorapidity (|η|<1) and jet p_T>15 GeV/c. Both average particle density and $$\langle$$p_T$$\rangle$$ depend weakly on the leading jet p_T. Closer inspection of the Transverse region hints that contributions to the underlying event from initial- and final-state radiation are significantly smaller in these collisions than at the higher energies, up to 13 TeV, recorded at the LHC. Underlying event measurements associated with a high-p_T jet will contribute to our understanding of QCD processes at hard and soft scales at RHIC energies, as well as provide constraints to modeling of underlying event dynamics.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Texas A & M Univ., College Station, TX (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP); USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF); Ministry of Education and Science of the Russian Federation; National Natural Science Foundation of China (NSFC); Chinese Academy of Science; Ministry of Science and Technology of China; Chinese Ministry of Education; National Research Foundation of Korea (NRF); Czech Science Foundation and Ministry of Education; Hungarian National Research Development and Innovation Office
• Contributing Organization: STAR Collaboration
• Grant/Contract Number: SC0012704; SC0015636; AC02-05CH11231
• OSTI ID: 1580259
• Alternate ID(s): OSTI ID: 1603834; OSTI ID: 1615319; OSTI ID: 1787635
• Report Number(s): BNL-212456-2019-JAAM; PRVDAQ; TRN: US2102254
• Journal Information: Physical Review D, Vol. 101, Issue 5; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English