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Adamczyk, Leszek ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alakhverdyants, A. V. ; Alekseev, Igor G. ; Alford, Jeremy ; Anderson, Bryon D. ; Anson, Christopher Daniel ; Arkhipkin, Dmitry A. ; Averichev, Georgy S. ; Balewski, Jan ; Banerjee, A. ; Barnovska, Z. ; Beavis, Dana Richard ; Bellwied, Rene ; Betancourt, M. J. ; Betts, R. R. ; Bhasin, Anju ; Bhati, Ashok Kumar ; Bichsel, Hans ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Borowski, W. ; Bouchet, J. ; Brandin, Andrei V. ; Brovko, S. G. ; Bruna, Elena ; Bueltmann, S. ; Bunzarov, Ivan ; Burton, T. P. ; Butterworth, Joseph ; Cai, Xiang-Zhou ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Cendejas, R. ; Cervantes, M. C. ; Chaloupka, Petr ; Chattopadhyay, S. ; Chen, H. F. ; Chen, J. H. ; Chen, J. Y. ; Chen, L. ; Cheng, J. ; Cherney, Michael Gerard ; Chikanian, Alexei ; Christie, William ; Chung, P. ; Chwastowski, J. ; Codrington, M. J. M. ; Corliss, R. ; Cramer, John G. ; Crawford, Henry J. ; Cui, X. ; Davila Leyva, A. ; De Silva, L. C. ; Debbe, R. R. ; Dedovich, T. G. ; Deng, J. ; Souza, Rafael Derradi de ; Dhamija, S. ; Didenko, Lidia ; Ding, F. ; Djawotho, P. ; Dong, X. ; Drachenberg, James Lucus ; Draper, James E. ; Du, C. M. ; Dunkelberger, L. E. ; Dunlop, James C. ; Efimov, Leonid G. ; Elnimr, M. ; Engelage, Jon M. ; Eppley, Geary Wareham ; Eun, L. ; Evdokimov, Olga Y. ; Fatemi, Renee H. ; Fedorišin, Jan ; Fersch, R. G. ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Gagliardi, Carl A. ; Gangadharan, Dhevan Raja ; Geurts, Frank ; Gliske, S. ; Gorbunov, Y. N. ; Grebenyuk, O. G. ; Grosnick, David P. ; Gupta, S. ; Guryn, Włodzimierz ; Haag, B. ; Hajkova, O. ; Hamed, Ahmed M. ; Han, L-X. ; Harris, John W. ; Hays-Wehle, J. P. ; Heppelmann, S. ; Hirsch, Andrew S. ; Hoffmann, Gerald W. ; Hofman, D. J. ; Horvat, S. ; Huang, Bingchu ; Huang, Huan Zhong ; Huck, P. ; Humanic, Thomas J. ; Huo, L. ; Igo, George J. ; Jacobs, William W. ; Jena, Chitrasen ; Joseph, J. ; Judd, Eleanor G. ; Kabana, Sonia ; Kang, K. ; Kapitan, J. ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kesich, A. ; Kettler, D. ; Kikola, D. P. ; Kiryluk, Joanna ; Kisiel, Adam Ryszard ; Kizka, V. ; Klein, Spencer Robert ; Koetke, Donald D. ; Kollegger, Thorsten ; Konzer, J. ; Koralt, I. ; Koroleva, L. ; Korsch, W. ; Kotchenda, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kumar, Lokesh ; Lamont, Matthew A. C. ; Landgraf, Jeffery M. ; LaPointe, S. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leight, W. ; LeVine, Micheal J. ; Li, C. ; Li, L. ; Li, W. ; Li, X. ; Li, X. ; Li, Y. ; Li, Z. M. ; Lima, L. M. ; Lisa, Michael A. ; Liu, F. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lu, Y. ; Luo, X. ; Luszczak, A. ; Ma, G. L. ; Ma, Yu-Gang ; Mahapatra, Durga Prasad ; Majka, Richard Daniel ; Mall, O. I. ; Margetis, Spyridon ; Markert, Christina ; Masui, H. ; Matis, Howard S. ; McDonald, Daniel ; McShane, Tom S. ; Mioduszewski, Saskia ; Mitrovski, M. K. ; Mohammed, Y. ; Mohanty, Bedangadas ; Morozov, B. ; Munhoz, Marcelo Gameiro ; Mustafa, M. K. ; Naglis, M. ; Nandi, Basanta Kumar ; Nasim, Md. ; Nayak, Tapan Kumar ; Nogach, Larisa V. ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, K. ; Ohlson, Alice ; Okorokov, Vitaly A. ; Oldag, E. W. ; Oliveira, R. A. N. ; Olson, Douglas L. ; Pachr, Miloš ; Page, Brian S. ; Pal, Susanta Kumar ; Pan, Y. X. ; Pandit, Y. ; Panebratsev, Yuri ; Pawlak, Tomasz Jan ; Pawlik, Bogdan ; Pei, Hua ; Perkins, Chris ; Peryt, Wiktor Stanislaw ; Pile, P. ; Planinic, Mirko ; Pluta, Jan Marian ; Plyku, D. ; Poljak, Nikola ; Porter, Jeffrey Brent ; Poskanzer, Arthur M. ; Powell, C. B. ; Prindle, Duncan J. ; Pruneau, Claude A. ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Pujahari, P. R. ; Putschke, Jörn H. ; Qiu, H. ; Raniwala, Rashmi ; Raniwala, Sudhir ; Ray, Robert L. ; Redwine, R. ; Reed, Rosi Jan ; Riley, C. K. ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sakrejda, Iwona ; Salur, Sevil ; Sandweiss, Jack H. ; Sangaline, E. ; Sarkar, Amal ; Schambach, Joachim ; Scharenberg, Rolf Paul ; Schmah, A. M. ; Schmitz, Norbert ; Schuster, T. R. ; Seele, J. ; Seger, Janet Elizabeth ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shao, M. ; Sharma, B. ; Sharma, Monika ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Singaraju, Rama Narayana ; Skoby, Michael J. ; Smirnov, Nikolai ; Solanki, D. ; Sorensen, Paul Richard ; deSouza, U. G. ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Steadman, S. G. ; Stevens, J. R. ; Stock, Reinhard ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Suarez, M. C. ; Šumbera, Michal ; Sun, X. M. ; Sun, Y. ; Sun, Z. ; Surrow, Bernd ; Svirida, Dmitry N. ; Symons, Timothy James MacNeil ; Toledo, Alejandro Szanto de ; Takahashi, Jun ; Tang, Aihong ; Tang, Zebo ; Tarini, L. H. ; Tarnowsky, Terence J. ; Thein, Dylan ; Thomas, James H. ; Tian, J. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Trainor, Thomas A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Trzeciak, Barbara Antonina ; Tsai, Oleg D. ; Turnau, J. ; Ullrich, Thomas ; Underwood, David G. ; Van Buren, Gene ; van Nieuwenhuizen, G. ; Vanfossen, J. A. ; Varma, Raghava ; Vasconcelos, G. M. S. ; Videbæk, Flemming ; Viyogi, Yogendra P. ; Vokal, Stanislav ; Voloshin, Sergei ; Vossen, A. ; Wada, M. ; Wang, F. ; Wang, G. ; Wang, H. ; Wang, J. S. ; Wang, Q. ; Wang, X. L. ; Wang, Y. ; Webb, Grant ; Webb, Jason C. ; Westfall, Gary D. ; Whitten, Charles A. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Witzke, W. ; Wu, Y. F. ; Xiao, Z. ; Xie, W. ; Xin, K. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; Xu, W. ; Xu, Y. ; Xu, Z. ; Xue, L. ; Yang, Y. ; Yang, Y. ; Yepes, Pablo P. ; Yi, Y. ; Yip, K. ; Yoo, I-K. ; Zawisza, M. ; Zbroszczyk, Hanna Paulina ; Zhang, J. B. ; Zhang, S. ; Zhang, W. M. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Z. P. ; Zhao, F. ; Zhao, J. ; Zhong, C. ; Zhu, X. ; Zhu, Y. H. ; Zoulkarneeva, Youlia
STAR's measurements of directed flow (v1) around midrapidity for π±, K±, K0S, p and p¯ in Au + Au collisions at $\sqrtsNN = 200$ GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, K0S and p¯). In 5-30% central collisions a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.
Adamczyk, Leszek ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alakhverdyants, A. V. ; Alekseev, Igor G. ; Alford, Jeremy ; Anderson, Bryon D. ; Anson, Christopher Daniel ; Arkhipkin, Dmitry A. ; Averichev, Georgy S. ; Balewski, Jan ; Banerjee, A. ; Barnovska, Z. ; Beavis, Dana Richard ; Bellwied, Rene ; Betancourt, M. J. ; Betts, R. R. ; Bhasin, Anju ; Bhati, Ashok Kumar ; Bichsel, Hans ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Borowski, W. ; Bouchet, J. ; Brandin, Andrei V. ; Brovko, S. G. ; Bruna, Elena ; Bueltmann, S. ; Bunzarov, Ivan ; Burton, T. P. ; Butterworth, Joseph ; Cai, Xiang-Zhou ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Cendejas, R. ; Cervantes, M. C. ; Chaloupka, Petr ; Chattopadhyay, S. ; Chen, H. F. ; Chen, J. H. ; Chen, J. Y. ; Chen, L. ; Cheng, J. ; Cherney, Michael Gerard ; Chikanian, Alexei ; Christie, William ; Chung, P. ; Chwastowski, J. ; Codrington, M. J. M. ; Corliss, R. ; Cramer, John G. ; Crawford, Henry J. ; Cui, X. ; Davila Leyva, A. ; De Silva, L. C. ; Debbe, R. R. ; Dedovich, T. G. ; Deng, J. ; Souza, Rafael Derradi de ; Dhamija, S. ; Didenko, Lidia ; Ding, F. ; Djawotho, P. ; Dong, X. ; Drachenberg, James Lucus ; Draper, James E. ; Du, C. M. ; Dunkelberger, L. E. ; Dunlop, James C. ; Efimov, Leonid G. ; Elnimr, M. ; Engelage, Jon M. ; Eppley, Geary Wareham ; Eun, L. ; Evdokimov, Olga Y. ; Fatemi, Renee H. ; Fedorišin, Jan ; Fersch, R. G. ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Gagliardi, Carl A. ; Gangadharan, Dhevan Raja ; Geurts, Frank ; Gliske, S. ; Gorbunov, Y. N. ; Grebenyuk, O. G. ; Grosnick, David P. ; Gupta, S. ; Guryn, Włodzimierz ; Haag, B. ; Hajkova, O. ; Hamed, Ahmed M. ; Han, L-X. ; Harris, John W. ; Hays-Wehle, J. P. ; Heppelmann, S. ; Hirsch, Andrew S. ; Hoffmann, Gerald W. ; Hofman, D. J. ; Horvat, S. ; Huang, Bingchu ; Huang, Huan Zhong ; Huck, P. ; Humanic, Thomas J. ; Huo, L. ; Igo, George J. ; Jacobs, William W. ; Jena, Chitrasen ; Joseph, J. ; Judd, Eleanor G. ; Kabana, Sonia ; Kang, K. ; Kapitan, J. ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kesich, A. ; Kettler, D. ; Kikola, D. P. ; Kiryluk, Joanna ; Kisiel, Adam Ryszard ; Kizka, V. ; Klein, Spencer Robert ; Koetke, Donald D. ; Kollegger, Thorsten ; Konzer, J. ; Koralt, I. ; Koroleva, L. ; Korsch, W. ; Kotchenda, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kumar, Lokesh ; Lamont, Matthew A. C. ; Landgraf, Jeffery M. ; LaPointe, S. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leight, W. ; LeVine, Micheal J. ; Li, C. ; Li, L. ; Li, W. ; Li, X. ; Li, X. ; Li, Y. ; Li, Z. M. ; Lima, L. M. ; Lisa, Michael A. ; Liu, F. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lu, Y. ; Luo, X. ; Luszczak, A. ; Ma, G. L. ; Ma, Yu-Gang ; Mahapatra, Durga Prasad ; Majka, Richard Daniel ; Mall, O. I. ; Margetis, Spyridon ; Markert, Christina ; Masui, H. ; Matis, Howard S. ; McDonald, Daniel ; McShane, Tom S. ; Mioduszewski, Saskia ; Mitrovski, M. K. ; Mohammed, Y. ; Mohanty, Bedangadas ; Morozov, B. ; Munhoz, Marcelo Gameiro ; Mustafa, M. K. ; Naglis, M. ; Nandi, Basanta Kumar ; Nasim, Md. ; Nayak, Tapan Kumar ; Nogach, Larisa V. ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, K. ; Ohlson, Alice ; Okorokov, Vitaly A. ; Oldag, E. W. ; Oliveira, R. A. N. ; Olson, Douglas L. ; Pachr, Miloš ; Page, Brian S. ; Pal, Susanta Kumar ; Pan, Y. X. ; Pandit, Y. ; Panebratsev, Yuri ; Pawlak, Tomasz Jan ; Pawlik, Bogdan ; Pei, Hua ; Perkins, Chris ; Peryt, Wiktor Stanislaw ; Pile, P. ; Planinic, Mirko ; Pluta, Jan Marian ; Plyku, D. ; Poljak, Nikola ; Porter, Jeffrey Brent ; Poskanzer, Arthur M. ; Powell, C. B. ; Prindle, Duncan J. ; Pruneau, Claude A. ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Pujahari, P. R. ; Putschke, Jörn H. ; Qiu, H. ; Raniwala, Rashmi ; Raniwala, Sudhir ; Ray, Robert L. ; Redwine, R. ; Reed, Rosi Jan ; Riley, C. K. ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sakrejda, Iwona ; Salur, Sevil ; Sandweiss, Jack H. ; Sangaline, E. ; Sarkar, Amal ; Schambach, Joachim ; Scharenberg, Rolf Paul ; Schmah, A. M. ; Schmitz, Norbert ; Schuster, T. R. ; Seele, J. ; Seger, Janet Elizabeth ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shao, M. ; Sharma, B. ; Sharma, Monika ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Singaraju, Rama Narayana ; Skoby, Michael J. ; Smirnov, Nikolai ; Solanki, D. ; Sorensen, Paul Richard ; deSouza, U. G. ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Steadman, S. G. ; Stevens, J. R. ; Stock, Reinhard ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Suarez, M. C. ; Šumbera, Michal ; Sun, X. M. ; Sun, Y. ; Sun, Z. ; Surrow, Bernd ; Svirida, Dmitry N. ; Symons, Timothy James MacNeil ; Toledo, Alejandro Szanto de ; Takahashi, Jun ; Tang, Aihong ; Tang, Zebo ; Tarini, L. H. ; Tarnowsky, Terence J. ; Thein, Dylan ; Thomas, James H. ; Tian, J. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Trainor, Thomas A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Trzeciak, Barbara Antonina ; Tsai, Oleg D. ; Turnau, J. ; Ullrich, Thomas ; Underwood, David G. ; Van Buren, Gene ; van Nieuwenhuizen, G. ; Vanfossen, J. A. ; Varma, Raghava ; Vasconcelos, G. M. S. ; Videbæk, Flemming ; Viyogi, Yogendra P. ; Vokal, Stanislav ; Voloshin, Sergei ; Vossen, A. ; Wada, M. ; Wang, F. ; Wang, G. ; Wang, H. ; Wang, J. S. ; Wang, Q. ; Wang, X. L. ; Wang, Y. ; Webb, Grant ; Webb, Jason C. ; Westfall, Gary D. ; Whitten, Charles A. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Witzke, W. ; Wu, Y. F. ; Xiao, Z. ; Xie, W. ; Xin, K. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; Xu, W. ; Xu, Y. ; Xu, Z. ; Xue, L. ; Yang, Y. ; Yang, Y. ; Yepes, Pablo P. ; Yi, Y. ; Yip, K. ; Yoo, I-K. ; Zawisza, M. ; Zbroszczyk, Hanna Paulina ; Zhang, J. B. ; Zhang, S. ; Zhang, W. M. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Z. P. ; Zhao, F. ; Zhao, J. ; Zhong, C. ; Zhu, X. ; Zhu, Y. H. ; Zoulkarneeva, Youlia
STAR's measurements of directed flow (v1) around midrapidity for π±, K±, K0S, p and p¯ in Au + Au collisions at $\sqrtsNN = 200$ GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, K0S and p¯). The proton v1(y) slope is found to be much closer to zero compared to antiprotons. A sizable difference is seen between v1 of protons and antiprotons in 5-30% central collisions. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. Anti-flow alone cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aparin, Alexey ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, F. G. ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; Chan, B. K. ; Chang, F-H. ; Chang, Z. ; Chankova-Bunzarova, N. ; Chatterjee, A. ; Chen, D. ; Chen, J. ; Chen, J. H. ; Chen, X. ; Chen, Z. ; Cheng, J. ; Cherney, Michael Gerard ; Chevalier, M. ; Choudhury, Subikash ; Christie, William ; Chu, Xiaoxuan ; Crawford, Henry J. ; Csanád, Máté ; Daugherity, M. ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dilks, Christopher ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, A. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, C. J. ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Francisco, Audrey ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Ghimire, Navagyan ; Gibson, Adam ; Gopal, Krishan ; Gou, X. ; Grosnick, David P. ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harabasz, Szymon ; Harris, John W. ; He, S. ; He, W. ; He, Xionghong ; He, Y. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Hoffman, E. ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Hu, Y. ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Isenhower, D. ; Jacobs, William W. ; Jena, Chitrasen ; Jentsch, Alexander ; Ji, Yuanjing ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kabir, M. L. ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Khyzhniak, Yevheniia V. ; Kikoła, Daniel P. ; Kim, C. ; Kimelman, B. ; Kincses, D. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kiselev, A. ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kulathunga Mudiyanselage, Nalinda ; Kumar, Lokesh ; Kumar, Shyam ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Lan, Shaowei ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leung, Yue Hang ; Li, C. ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lin, Y. ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, Tong ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lukow, N. S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Mazer, Joel Anthony ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nagy, M. ; Nam, J. D. ; Nasim, Md. ; Nayak, Kishora ; Neff, D. ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Nunes, A. S. ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Pandav, Ashish ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pawłowska, Diana ; Pei, Hua ; Perkins, Chris ; Pinsky, Lawrence ; Pintér, Roland Laszlo ; Pluta, Jan Marian ; Pokhrel, B. R. ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Qiu, H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sako, H. ; Salur, Sevil ; Sandweiss, Jack H. ; Sato, Susumu ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Sheikh, Ashik Ikbal ; Shen, W. Q. ; Shi, Shusu ; Shi, Y. ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stefaniak, Maria ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, X. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, Zhoudunming ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, J. S. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Wang, Z. ; Webb, Jason C. ; Weidenkaff, Philipp ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; 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. ; Yu, Y. ; Zbroszczyk, Hanna Paulina ; Zha, Wangmei ; Zhang, C. ; Zhang, Dingwei ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Y. ; Zhang, Z. J. ; Zhang, Z. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
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.
Measurement of inclusive charged-particle jet production in Au+Au collisions at √sNN = 200 GeV
(2021)
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aparin, Alexey ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, F. G. ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; 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, Michael Gerard ; Chevalier, M. ; Choudhury, Subikash ; Christie, William ; Chu, Xiaoxuan ; Crawford, Henry J. ; Csanád, Máté ; Daugherity, M. ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, A. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, C. J. ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Francisco, Audrey ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Gopal, Krishan ; Grosnick, David P. ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harabasz, Szymon ; Harris, John W. ; He, S. ; He, W. ; He, X. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Hoffman, E. ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Hu, Y. ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Isenhower, D. ; Jacobs, Peter Martin ; Jacobs, William W. ; Jena, Chitrasen ; Jentsch, Alexander ; JI, Yuanjing ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kabir, M. L. ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Khyzhniak, Yevheniia V. ; Kikoła, Daniel P. ; Kim, C. ; Kimelman, B. ; Kincses, D. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kiselev, A. ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Mudiyanselage, N. Kulathunga ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Lan, Shaowei ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leung, Yue Hang ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lin, Y. ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, Tong ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lukow, N. S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Mazer, Joel Anthony ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nagy, M. ; Nam, J. D. ; Nasim, Md. ; Nayak, Kishora ; Neff, D. ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Pandav, Ashish ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pawłowska, Diana ; Pei, Hua ; Perkins, Chris ; Pinsky, Lawrence ; Pintér, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Qiu, H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sako, H. ; Salur, Sevil ; Sandweiss, Jack H. ; Sato, Susumu ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stefaniak, Maria ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, X. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, Zhoudunming ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, J. S. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Wang, Z. ; Webb, Jason C. ; Weidenkaff, Philipp ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; 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, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Y. ; Zhang, Z. J. ; Zhang, Z. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at sNN−−−−√=200 GeV. Jets are reconstructed with the anti-kT algorithm using charged tracks with pseudorapidity |η|<1.0 and transverse momentum 0.2<pchT,jet<30 GeV/c, with jet resolution parameter R=0.2, 0.3, and 0.4. The large background yield uncorrelated with the jet signal is observed to be dominated by statistical phase space, consistent with a previous coincidence measurement. This background is suppressed by requiring a high-transverse-momentum (high-pT) leading hadron in accepted jet candidates. The bias imposed by this requirement is assessed, and the pT region in which the bias is small is identified. Inclusive charged-particle jet distributions are reported in peripheral and central Au+Au collisions for 5<pchT,jet<25 GeV/c and 5<pchT,jet<30 GeV/c, respectively. The charged-particle jet inclusive yield is suppressed for central Au+Au collisions, compared to both the peripheral Au+Au yield from this measurement and to the pp yield calculated using the PYTHIA event generator. The magnitude of the suppression is consistent with that of inclusive hadron production at high pT, and that of semi-inclusive recoil jet yield when expressed in terms of energy loss due to medium-induced energy transport. Comparison of inclusive charged-particle jet yields for different values of R exhibits no significant evidence for medium-induced broadening of the transverse jet profile for R<0.4 in central Au+Au collisions. The measured distributions are consistent with theoretical model calculations that incorporate jet quenching.
Measurement of inclusive J/ψ polarization in p + p collisions at √s=200 GeV by the STAR experiment
(2020)
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aparin, Alexey ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, F. G. ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Bueltmann, S. ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; 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, Michael Gerard ; Chevalier, M. ; Choudhury, Subikash ; Christie, William ; Crawford, Henry J. ; Csanád, Máté ; Daugherity, M. ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, A. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, C. J. ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Francisco, Audrey ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Gopal, Krishan ; Grosnick, David P. ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harris, John W. ; He, S. ; He, W. ; He, X. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Hoffman, E. ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Hu, Y. ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Isenhower, D. ; Jacobs, William W. ; Jena, Chitrasen ; Jentsch, Alexander ; JI, Yuanjing ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kabir, M. L. ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Khyzhniak, Yevheniia V. ; Kikoła, Daniel P. ; Kim, C. ; Kimelman, B. ; Kincses, D. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kiselev, A. ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kulathunga Mudiyanselage, Nalinda ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Lan, Shaowei ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leung, Yue Hang ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lin, Y. ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, Tong ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lukow, N. S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Mazer, Joel Anthony ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nagy, M. ; Nam, J. D. ; Nasim, Md. ; Nayak, Kishora ; Neff, D. ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Pandav, Ashish ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pawłowska, Diana ; Pei, Hua ; Perkins, Chris ; Pinsky, Lawrence ; Pintér, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Qiu, H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sako, H. ; Salur, Sevil ; Sandweiss, Jack H. ; Sato, Susumu ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stefaniak, Maria ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, Zhoudunming ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, J. S. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Wang, Z. ; Webb, Jason C. ; Weidenkaff, Philipp ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; 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, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Y. ; Zhang, Z. J. ; Zhang, Z. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
We report on new measurements of inclusive 𝐽/𝜓 polarization at midrapidity in 𝑝+𝑝 collisions at √𝑠=200 GeV by the STAR experiment at the Relativistic Heavy Ion Collider. The polarization parameters, 𝜆𝜃, 𝜆𝜙, and 𝜆𝜃𝜙, are measured as a function of transverse momentum (𝑝T) in both the helicity and Collins-Soper (CS) reference frames within 𝑝T<10 GeV/𝑐. Except for 𝜆𝜃 in the CS frame at the highest measured 𝑝T, all three polarization parameters are consistent with 0 in both reference frames without any strong 𝑝T dependence. Several model calculations are compared with data, and the one using the Color Glass Condensate effective field theory coupled with nonrelativistic QCD gives the best overall description of the experimental results, even though other models cannot be ruled out due to experimental uncertainties.
Measurement of inclusive charged-particle jet production in Au + Au collisions at √sNN=200 GeV
(2020)
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aparin, Alexey ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, F. G. ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; 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, Michael Gerard ; Chevalier, M. ; Choudhury, Subikash ; Christie, William ; Chu, Xiaoxuan ; Crawford, Henry J. ; Csanád, Máté ; Daugherity, M. ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, A. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, C. J. ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Francisco, Audrey ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Gopal, Krishan ; Grosnick, David P. ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harabasz, Szymon ; Harris, John W. ; He, S. ; He, W. ; He, X. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Hoffman, E. ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Hu, Y. ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Isenhower, D. ; Jacobs, Peter Martin ; Jacobs, William W. ; Jena, Chitrasen ; Jentsch, Alexander ; JI, Yuanjing ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kabir, M. L. ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Khyzhniak, Yevheniia V. ; Kikoła, Daniel P. ; Kim, C. ; Kimelman, B. ; Kincses, D. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kiselev, A. ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kulathunga Mudiyanselage, Nalinda ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Lan, Shaowei ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leung, Yue Hang ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lin, Y. ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, Tong ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lukow, N. S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Mazer, Joel Anthony ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nagy, M. ; Nam, J. D. ; Nasim, Md. ; Nayak, Kishora ; Neff, D. ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Pandav, Ashish ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pawłowska, Diana ; Pei, Hua ; Perkins, Chris ; Pinsky, Lawrence ; Pintér, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Qiu, H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sako, H. ; Salur, Sevil ; Sandweiss, Jack H. ; Sato, Susumu ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stefaniak, Maria ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, X. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, Zhoudunming ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, J. S. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Wang, Z. ; Webb, Jason C. ; Weidenkaff, Philipp ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; 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, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Y. ; Zhang, Z. J. ; Zhang, Z. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at √𝑠𝑁𝑁=200 GeV. Jets are reconstructed with the anti-𝑘𝑇 algorithm using charged tracks with pseudorapidity |𝜂|<1.0 and transverse momentum 0.2<𝑝ch
𝑇,jet<30 GeV/𝑐, with jet resolution parameter 𝑅=0.2, 0.3, and 0.4. The large background yield uncorrelated with the jet signal is observed to be dominated by statistical phase space, consistent with a previous coincidence measurement. This background is suppressed by requiring a high-transverse-momentum (high-𝑝𝑇) leading hadron in accepted jet candidates. The bias imposed by this requirement is assessed, and the 𝑝𝑇 region in which the bias is small is identified. Inclusive charged-particle jet distributions are reported in peripheral and central Au+Au collisions for 5<𝑝ch
𝑇,jet<25 GeV/𝑐 and 5<𝑝ch
𝑇,jet<30 GeV/𝑐, respectively. The charged-particle jet inclusive yield is suppressed for central Au+Au collisions, compared to both the peripheral Au+Au yield from this measurement and to the 𝑝𝑝 yield calculated using the PYTHIA event generator. The magnitude of the suppression is consistent with that of inclusive hadron production at high 𝑝𝑇 and that of semi-inclusive recoil jet yield when expressed in terms of energy loss due to medium-induced energy transport. Comparison of inclusive charged-particle jet yields for different values of 𝑅 exhibits no significant evidence for medium-induced broadening of the transverse jet profile for 𝑅 <0.4 in central Au+Au collisions. The measured distributions are consistent with theoretical model calculations that incorporate jet quenching.
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aparin, Alexey ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, F. G. ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; 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, Michael Gerard ; Chevalier, M. ; Choudhury, Subikash ; Christie, William ; Chu, Xiaoxuan ; Crawford, Henry J. ; Csanád, Máté ; Daugherity, M. ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, A. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, C. J. ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Francisco, Audrey ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Gopal, Krishan ; Grosnick, David P. ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harabasz, Szymon ; Harris, John W. ; He, S. ; He, W. ; He, Xionghong ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Hoffman, E. ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Hu, Y. ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Isenhower, D. ; Jacobs, William W. ; Jena, Chitrasen ; Jentsch, Alexander ; JI, Yuanjing ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kabir, M. L. ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Khyzhniak, Yevheniia V. ; Kikoła, Daniel P. ; Kim, C. ; Kimelman, B. ; Kincses, D. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kiselev, A. ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kulathunga Mudiyanselage, Nalinda ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Lan, Shaowei ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Leung, Yue Hang ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lin, Y. ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, Tong ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Longacre, Ronald S. ; Lukow, N. S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Mazer, Joel Anthony ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nagy, M. ; Nam, J. D. ; Nasim, Md. ; Nayak, Kishora ; Neff, D. ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Nunes, A. S. ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Pandav, Ashish ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pawłowska, Diana ; Pei, Hua ; Perkins, Chris ; Pinsky, Lawrence ; Pintér, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Qiu, H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Sahoo, Nihar Ranjan ; Sako, H. ; Salur, Sevil ; Sandweiss, Jack H. ; Sato, Susumu ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stefaniak, Maria ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, X. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Tlusty, David ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, Zhoudunming ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, J. S. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Wang, Z. ; Webb, Jason C. ; Weidenkaff, Philipp ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; 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, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Y. ; Zhang, Z. J. ; Zhang, Z. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
We report on the measurement of the Central Exclusive Production of charged particle pairs h+h− (h = π, K, p) with the STAR detector at RHIC in proton-proton collisions at √s = 200 GeV. The charged particle pairs produced in the reaction pp → p′ + h+h− + p′ are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles’ transverse momenta and pseudorapidities as well as by the forward-scattered protons’ momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0.04 GeV2 < −t1, −t2 < 0.2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range |η| < 0.7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of π+π− and K+K− pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to π+π− production. For π+π− production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f0(980), f2(1270) and f0(1500), with a possible small contribution from the f0(1370). Fits to the extrapolated differential cross section as a function of t1 and t2 enable extraction of the exponential slope parameters in several bins of the invariant mass of π+π− pairs. These parameters are sensitive to the size of the interaction region.
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aoyama, Ryo ; Aparin, Alexey ; Arkhipkin, Dmitry A. ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, Fareha ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Bassill, Aaron J. ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bhati, Ashok Kumar ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Brown, D. ; Bryslawskyj, Jason ; Bunzarov, Ivan ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; Chan, B. K. ; Chang, F-H. ; Chang, Z. ; Chankova-Bunzarova, N. ; Chatterjee, A. ; Chattopadhyay, S. ; Chen, J. H. ; Chen, X. ; Cheng, J. ; Cherney, Michael Gerard ; Christie, William ; Contin, Giacomo ; Crawford, Henry J. ; Csanád, Máté ; Das, Supriya ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dilks, Christopher ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Efimov, Leonid G. ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, J. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Flores, C. E. ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Grosnick, David P. ; Gunarathne, D. S. ; Gupta, Anik ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harlenderova, Alena ; Harris, John W. ; He, L. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Huang, Bingchu ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Jacobs, William W. ; Jentsch, Alexander ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Kikoła, Daniel P. ; Kim, C. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kraishan, A. F. ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Kulathunga Mudiyanselage, Nalinda ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kvapil, Jakub ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lidrych, J. ; Lin, T. ; Lipiec, Andrzej ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Lomnitz, M. ; Longacre, Ronald S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Matonoha, Oliver ; Mazer, Joel Anthony ; Meehan, K. ; Mei, J. C. ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mishra, Debadeepti ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nasim, Md. ; Nayak, Kishora ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, K. ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Olvitt, D. ; Page, Brian S. ; Pak, Robert ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pei, Hua ; Perkins, Chris ; Pinter, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Rusnakova, O. ; Sahoo, Nihar Ranjan ; Sahu, Pradip Kumar ; Salur, Sevil ; Sandweiss, Jack H. ; Schambach, Joachim ; Schmah, A. M. ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Siejka, Sebastian ; Sikora, Rafał ; Šimko, Miroslav ; Singh, J. ; Singha, Subhash ; Smirnov, Dmitri V. ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Sugiura, Tetsuro ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Todoroki, Takahito ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, B. ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Vossen, A. ; Wang, F. ; Wang, G. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Webb, Jason C. ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; Xu, Y. F. ; Xu, Z. ; Yang, C. ; Yang, Q. ; Yang, S. ; Yang, Y. ; Ye, Z. ; Ye, Z. ; Yi, L. ; Yip, K. ; Yoo, I. -K. ; Zbroszczyk, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, J. ; Zhang, L. ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
We report new STAR measurements of the single-spin asymmetries 𝐴𝐿 for 𝑊+ and 𝑊− bosons produced in polarized proton-proton collisions at √𝑠=510 GeV as a function of the decay-positron and decay-electron pseudorapidity. The data were obtained in 2013 and correspond to an integrated luminosity of 250 pb−1. The results are combined with previous results obtained with 86 pb−1. A comparison with theoretical expectations based on polarized lepton-nucleon deep-inelastic scattering and prior polarized proton-proton data suggests a difference between the ¯𝑢 and ¯𝑑 quark helicity distributions for 0.05<𝑥<0.25. In addition, we report new results for the double-spin asymmetries 𝐴𝐿𝐿 for 𝑊±, as well as 𝐴𝐿 for 𝑍/𝛾* production and subsequent decay into electron-positron pairs.
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aoyama, Ryo ; Aparin, Alexey ; Arkhipkin, Dmitry A. ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, Fareha ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Bassill, Aaron J. ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bhati, Ashok Kumar ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Bryslawskyj, Jason ; Bunzarov, Ivan ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; Chan, B. K. ; Chang, F-H. ; Chang, Z. ; Chankova-Bunzarova, N. ; Chatterjee, A. ; Chattopadhyay, S. ; Chen, J. H. ; Chen, X. ; Cheng, J. ; Cherney, Michael Gerard ; Christie, William ; Crawford, Henry J. ; Csanád, Máté ; Das, Supriya ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dilks, Christopher ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, J. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Grosnick, David P. ; Gupta, Anik ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harris, John W. ; He, L. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Huang, Bingchu ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Jacobs, William W. ; Jentsch, Alexander ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Kikoła, Daniel P. ; Kim, C. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Mudiyanselage, N. Kulathunga ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lipiec, Andrzej ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Lomnitz, M. ; Longacre, Ronald S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Matonoha, Oliver ; Mazer, Joel Anthony ; Meehan, K. ; Mei, J. C. ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mishra, Debadeepti ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nasim, Md. ; Nayak, Kishora ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, K. ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pei, Hua ; Perkins, Chris ; Pinter, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Rusnakova, O. ; Sahoo, Nihar Ranjan ; Sahu, Pradip Kumar ; Salur, Sevil ; Sandweiss, Jack H. ; Schambach, Joachim ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Siejka, Sebastian ; Sikora, Rafał ; Šimko, Miroslav ; JSingh ; Singha, Subhash ; Smirnov, Dmitri V. ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Sugiura, Tetsuro ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Todoroki, Takahito ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, B. ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Webb, Jason C. ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; Xu, Y. F. ; Xu, Z. ; Yang, C. ; Yang, Q. ; Yang, S. ; Yang, Yi ; Ye, Z. ; Ye, Z. ; Yi, L. ; Yip, K. ; Yoo, In-Kwon ; Zbroszczyk, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, L. ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
We report on the first measurements of J/ψ production at very low transverse momentum (pT< 0.2 GeV/c) in hadronic Au+Au collisions at √sNN = 200 GeV and U+U collisions at √sNN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/ψ at mid-rapidity in Au+Au (U+U) collisions reaches about 24 (52) for pT< 0.05 GeV/c in the 60-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/ψ for the very low pT range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semi-central collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/ψ yield observed at extremely low pT originates from coherent photon-nucleus interactions. In particular, coherently produced J/ψ's in violent hadronic collisions may provide a novel probe of the quark-gluon-plasma.
Adam, Jaroslav ; Adamczyk, Leszek ; Adams, Joseph R. ; Adkins, J. Kevin ; Agakishiev, Geydar ; Aggarwal, Madan Mohan ; Ahammed, Zubayer ; Alekseev, Igor G. ; Anderson, Derek M. ; Aoyama, Ryo ; Aparin, Alexey ; Arkhipkin, Dmitry A. ; Aschenauer, Elke Caroline ; Ashraf, Muhammad Usman ; Atetalla, Fareha ; Attri, Anjali ; Averichev, Georgy S. ; Bairathi, Vipul ; Barish, Kenneth ; Bassill, Aaron J. ; Behera, Arabinda ; Bellwied, Rene ; Bhasin, Anju ; Bhati, Ashok Kumar ; Bielčík, Jaroslav ; Bielčíková, Jana ; Bland, Leslie C. ; Bordyuzhin, Igor G. ; Brandenburg, James D. ; Brandin, Andrei V. ; Bryslawskyj, Jason ; Bunzarov, Ivan ; Butterworth, Joseph ; Caines, Helen Louise ; Calderón de la Barca Sánchez, Manuel ; Cebra, Daniel A. ; Chakaberia, Irakli ; Chaloupka, Petr ; Chan, B. K. ; Chang, F-H. ; Chang, Z. ; Chankova-Bunzarova, N. ; Chatterjee, A. ; Chattopadhyay, S. ; Chen, J. H. ; Chen, X. ; Cheng, J. ; Cherney, Michael Gerard ; Christie, William ; Crawford, Henry J. ; Csanád, Máté ; Das, Supriya ; Dedovich, T. G. ; Deppner, Ingo Martin ; Derevschikov, Anatoly A. ; Didenko, Lidia ; Dilks, Christopher ; Dong, X. ; Drachenberg, James Lucus ; Dunlop, James C. ; Edmonds, Terrence ; Elsey, Nicholas ; Engelage, Jon M. ; Eppley, Geary Wareham ; Esha, Roli ; Esumi, ShinIchi ; Evdokimov, Olga Y. ; Ewigleben, J. ; Eyser, Kjeld Oleg ; Fatemi, Renee H. ; Fazio, Salvatore ; Federič, Pavol ; Fedorišin, Jan ; Feng, Yicheng ; Filip, Peter ; Finch, Evan ; Fisyak, Yuri V. ; Fulek, Łukasz ; Gagliardi, Carl A. ; Galatyuk, Tetyana ; Geurts, Frank ; Gibson, Adam ; Grosnick, David P. ; Gupta, Anik ; Guryn, Włodzimierz ; Hamad, A. I. ; Hamed, Ahmed M. ; Harris, John W. ; He, L. ; Heppelmann, S. ; Heppelmann, S. ; Herrmann, Norbert ; Holub, Lukáš ; Hong, Y. ; Horvat, S. ; Huang, Bingchu ; Huang, Huan Zhong ; Huang, Shengli ; Huang, T. ; Huang, X. ; Humanic, Thomas J. ; Huo, P. ; Igo, George J. ; Jacobs, William W. ; Jentsch, Alexander ; Jia, Jiangyong ; Jiang, K. ; Jowzaee, S. ; Ju, Xin-Yue ; Judd, Eleanor G. ; Kabana, Sonia ; Kagamaster, Skipper ; Kalinkin, Dmitry ; Kang, K. ; Kapukchyan, David ; Kauder, Kolja ; Ke, Hongwei ; Keane, Declan ; Kechechyan, Armen ; Kelsey, Matthew ; Kikoła, Daniel P. ; Kim, C. ; Kinghorn, Todd Adler ; Kisel, Ivan ; Kisiel, Adam Ryszard ; Kocan, Michal ; Kočenda, L. M. ; Kosarzewski, Leszek Krzysztof ; Kramarik, L. ; Kravtsov, Peter ; Krueger, Keith William ; Mudiyanselage, N. Kulathunga ; Kumar, Lokesh ; Kunnawalkam Elayavalli, Raghav ; Kwasizur, Joseph H. ; Lacey, Roy Alphanso ; Landgraf, Jeffery M. ; Lauret, Jerome ; Lebedev, Alexei ; Lednicky, Richard ; Lee, J. H. ; Li, C. ; Li, W. ; Li, W. ; Li, X. ; Li, Y. ; Liang, Y. ; Licenik, Robert ; Lin, T. ; Lipiec, Andrzej ; Lisa, Michael A. ; Liu, F. ; Liu, H. ; Liu, P. ; Liu, P. ; Liu, X. ; Liu, Y. ; Liu, Z. ; Ljubicic, Tonko A. ; Llope, William Joseph ; Lomnitz, M. ; Longacre, Ronald S. ; Luo, S. ; Luo, X. ; Ma, G. L. ; Ma, L. ; Ma, R. ; Ma, Yu-Gang ; Magdy Abdelwahab Abdelrahman, Niseem ; Majka, Richard Daniel ; Mallick, Dukhishyam ; Margetis, Spyridon ; Markert, Christina ; Matis, Howard S. ; Matonoha, Oliver ; Mazer, Joel Anthony ; Meehan, K. ; Mei, J. C. ; Minaev, Nikolai G. ; Mioduszewski, Saskia ; Mishra, Debadeepti ; Mohanty, Bedangadas ; Mouli, Mriganka Mouli ; Mooney, Isaac A. ; Moravcova, Zuzana ; Morozov, Dmitry A. ; Nasim, Md. ; Nayak, Kishora ; Nelson, John M. ; Nemes, Daniel B. ; Nie, M. ; Nigmatkulov, Grigory A. ; Niida, Takafumi ; Nogach, Larisa V. ; Nonaka, Toshihiro ; Odyniec, Grazyna Janina ; Ogawa, Akio ; Oh, K. ; Oh, Saehanseul ; Okorokov, Vitaly A. ; Page, Brian S. ; Pak, Robert ; Panebratsev, Yuri ; Pawlik, Bogdan ; Pei, Hua ; Perkins, Chris ; Pinter, Roland Laszlo ; Pluta, Jan Marian ; Porter, Jeffrey Brent ; Posik, Matthew ; Pruthi, Navneet Kumar ; Przybycien, Mariusz ; Putschke, Jörn H. ; Quintero, Amilkar ; Radhakrishnan, Sooraj Krishnan ; Ramachandran, Suvarna ; Ray, Robert L. ; Reed, Rosi Jan ; Ritter, Hans Georg ; Roberts, Jabus B. ; Rogačevskij, Oleg V. ; Romero, Juan L. ; Ruan, L. ; Rusnak, Jan ; Rusnakova, O. ; Sahoo, Nihar Ranjan ; Sahu, Pradip Kumar ; Salur, Sevil ; Sandweiss, Jack H. ; Schambach, Joachim ; Schmidke, William B. ; Schmitz, Norbert ; Schweid, Benjamin R. ; Seck, Florian ; Seger, Janet Elizabeth ; Sergeeva, Maria ; Seto, Richard ; Seyboth, Peter ; Shah, N. ; Shahaliev, Ehtiram ; Shanmuganathan, Prashanth V. ; Shao, M. ; Shen, F. ; Shen, W. Q. ; Shi, Shusu ; Shou, Q. Y. ; Sichtermann, Ernst P. ; Siejka, Sebastian ; Sikora, Rafał ; Šimko, Miroslav ; JSingh ; Singha, Subhash ; Smirnov, Dmitri V. ; Smirnov, Nikolai ; Solyst, William ; Sorensen, Paul Richard ; Spinka, Harold. M. ; Srivastava, B. ; Stanislaus, T. D. Shirvel ; Stewart, David J. ; Strichanov, Michail Nikolaevič ; Stringfellow, Blair ; Suaide, Alexandre Alarcon do Passo ; Sugiura, Tetsuro ; Šumbera, Michal ; Summa, Branden ; Sun, X. M. ; Sun, Y. ; Sun, Y. ; Surrow, Bernd ; Svirida, Dmitry N. ; Szymański, Paweł ; Tang, Aihong ; Tang, Zebo ; Taranenko, Arkadiy ; Tarnowsky, Terence J. ; Thomas, James H. ; Timmins, Anthony Robert ; Todoroki, Takahito ; Tokarev, Mikhail V. ; Tomkiel, C. A. ; Trentalange, Stephen ; Tribble, Robert E. ; Tribedy, Prithwish ; Tripathy, Srikanta Kumar ; Tsai, Oleg D. ; Tu, B. ; Ullrich, Thomas ; Underwood, David G. ; Upsal, Isaac ; Van Buren, Gene ; Vanek, Jan ; Vasiliev, Alexander Nikolaevich ; Vassiliev, Iouri ; Videbæk, Flemming ; Vokal, Stanislav ; Voloshin, Sergei ; Wang, F. ; Wang, G. ; Wang, P. ; Wang, Y. ; Wang, Y. ; Webb, Jason C. ; Wen, L. ; Westfall, Gary D. ; Wieman, Howard ; Wissink, Scott W. ; Witt, Richard ; Wu, Y. ; Xiao, Z. G. ; Xie, Guannan ; Xie, W. ; Xu, H. ; Xu, N. ; Xu, Qinghua ; Xu, Y. F. ; Xu, Z. ; Yang, C. ; Yang, Q. ; Yang, S. ; Yang, Yi ; Ye, Z. ; Ye, Z. ; Yi, L. ; Yip, K. ; Yoo, In-Kwon ; Zbroszczyk, Hanna Paulina ; Zha, Wangmei ; Zhang, Dingwei ; Zhang, L. ; Zhang, S. ; Zhang, S. ; Zhang, X. P. ; Zhang, Y. ; Zhang, Z. ; Zhao, J. ; Zhong, C. ; Zhou, C. ; Zhu, X. ; Zhu, Z. ; Żurek, Maria Katarzyna ; Zyzak, Maksym
We report on the first measurements of J/ψ production at very low transverse momentum (pT< 0.2 GeV/c) in hadronic Au+Au collisions at √sNN = 200 GeV and U+U collisions at √sNN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/ψ at mid-rapidity in Au+Au (U+U) collisions reaches about 24 (52) for pT< 0.05 GeV/c in the 60-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/ψ for the very low pT range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semi-central collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/ψ yield observed at extremely low pT originates from coherent photon-nucleus interactions. In particular, coherently produced J/ψ's in violent hadronic collisions may provide a novel probe of the quark-gluon-plasma.