Measurement of transverse single-spin asymmetries of pi(0) and electromagnetic jets at forward rapidity in 200 and 500 GeV transversely polarized proton-proton collisions Academic Article uri icon

abstract

  • The STAR Collaboration reports measurements of the transverse single-spin asymmetry (TSSA) of inclusive $pi^0$ at center-of-mass energies ($sqrt s$) 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 $sqrt s$ from 19.4 GeV to 500 GeV is found. To investigate the underlying physics leading to this large TSSA, different topologies have been studied. $pi^0$ with no nearby particles tend to have a higher TSSA than inclusive $pi^0$. 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 $pi^0$ asymmetry as a function of Feynman-$x$. To investigate final-state effects, the Collins asymmetry of $pi^0$ inside electromagnetic jets has been measured. The Collins asymmetry is analyzed for its dependence on the $pi^0$ momentum transverse to the jet thrust axis and its dependence on the fraction of jet energy carried by the $pi^0$. 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 proceedings

  • PHYSICAL REVIEW D

altmetric score

  • 0.25

author list (cited authors)

  • Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., ... Zyzak, M.

citation count

  • 14

complete list of authors

  • 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||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, J||Chen, JH||Chen, X||Chen, Z||Cheng, J||Cherney, M||Chevalier, M||Choudhury, S||Christie, W||Chu, X||Crawford, HJ||Csanad, 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||Holub, L||Hong, Y||Horvat, S||Hu, Y||Huang, HZ||Huang, SL||Huang, T||Huang, X||Humanic, TJ||Huo, P||Igo, G||Isenhower, D||Jacobs, WW||Jena, C||Jentsch, A||Ji, Y||Jia, J||Jiang, K||Jowzaee, S||Ju, X||Judd, EG||Kabana, S||Kabir, ML||Kagamaster, S||Kalinkin, D||Kang, K||Kapukchyan, D||Kauder, K||Ke, HW||Keane, D||Kechechyan, A||Kelsey, M||Khyzhniak, YV||Kikola, DP||Kim, C||Kimelman, B||Kincses, D||Kinghorn, TA||Kisel, I||Kiselev, A||Kocan, M||Kochenda, L||Kosarzewski, LK||Kramarik, L||Kravtsov, P||Krueger, K||Mudiyanselage, N Kulathunga||Kumar, L||Kumar, S||Elayavalli, R Kunnawalkam||Kwasizur, JH||Lacey, R||Lan, S||Landgraf, JM||Lauret, J||Lebedev, A||Lednicky, R||Lee, JH||Leung, YH||Li, C||Li, W||Li, X||Li, Y||Liang, Y||Licenik, R||Lin, T||Lin, Y||Lisa, MA||Liu, F||Liu, H||Liu, P||Liu, T||Liu, X||Liu, Y||Liu, Z||Ljubicic, T||Llope, WJ||Longacre, RS||Lukow, NS||Luo, S||Luo, X||Ma, GL||Ma, L||Ma, R||Ma, YG||Magdy, N||Majka, R||Mallick, D||Margetis, S||Markert, C||Matis, HS||Mazer, JA||Minaev, NG||Mioduszewski, S||Mohanty, B||Mondal, MM||Mooney, I||Moravcova, Z||Morozov, DA||Nagy, M||Nam, JD||Nasim, Md||Nayak, K||Neff, D||Nelson, JM||Nemes, DB||Nie, M||Nigmatkulov, G||Niida, T||Nogach, LV||Nonaka, T||Nunes, AS||Odyniec, G||Ogawa, A||Oh, S||Okorokov, VA||Page, BS||Pak, R||Pandav, A||Panebratsev, Y||Pawlik, B||Pawlowska, D||Pei, H||Perkins, C||Pinsky, L||Pinter, RL||Pluta, J||Pokhrel, BR||Porter, J||Posik, M||Pruthi, NK||Przybycien, M||Putschke, J||Qiu, H||Quintero, A||Radhakrishnan, SK||Ramachandran, S||Ray, RL||Reed, R||Ritter, HG||Rogachevskiy, OV||Romero, JL||Ruan, L||Rusnak, J||Sahoo, NR||Sako, H||Salur, S||Sandweiss, J||Sato, S||Schmidke, WB||Schmitz, N||Schweid, BR||Seck, F||Seger, J||Sergeeva, M||Seto, R||Seyboth, P||Shah, N||Shahaliev, E||Shanmuganathan, PV||Shao, M||Sheikh, AI||Shen, WQ||Shi, SS||Shi, Y||Shou, QY||Sichtermann, EP||Sikora, R||Simko, M||Singh, J||Singha, S||Smirnov, N||Solyst, W||Sorensen, P||Spinka, HM||Srivastava, B||Stanislaus, TDS||Stefaniak, M||Stewart, DJ||Strikhanov, M||Stringfellow, B||Suaide, AAP||Sumbera, M||Summa, B||Sun, XM||Sun, X||Sun, Y||Surrow, B||Svirida, DN||Szymanski, P||Tang, AH||Tang, Z||Taranenko, A||Tarnowsky, T||Thomas, JH||Timmins, AR||Tlusty, D||Tokarev, M||Tomkiel, CA||Trentalange, S||Tribble, RE||Tribedy, P||Tripathy, SK||Tsai, OD||Tu, Z||Ullrich, T||Underwood, DG||Upsal, I||Van Buren, G||Vanek, J||Vasiliev, AN||Vassiliev, I||Videbaek, F||Vokal, S||Voloshin, SA||Wang, F||Wang, G||Wang, JS||Wang, P||Wang, Y||Wang, Z||Webb, JC||Weidenkaff, PC||Wen, L||Westfall, GD||Wieman, H||Wissink, SW||Witt, R||Wu, Y||Xiao, ZG||Xie, G||Xie, W||Xu, H||Xu, N||Xu, QH||Xu, YF||Xu, Y||Xu, Z||Yang, C||Yang, Q||Yang, S||Yang, Y||Yang, Z||Ye, Z||Yi, L||Yip, K||Yu, Y||Zbroszczyk, H||Zha, W||Zhang, C||Zhang, D||Zhang, S||Zhang, XP||Zhang, Y||Zhang, ZJ||Zhang, Z||Zhao, J||Zhong, C||Zhou, C||Zhu, X||Zhu, Z||Zurek, M||Zyzak, M

publication date

  • May 2021