Open Access

Precision measurement of the longitudinal double-spin asymmetry for dijet production at intermediate pseudorapidity in polarized $p p$ collisions at $\sqrt{s} = 200 GeV$

B. E. Aboona⁵⁷, J. Adam¹⁷, L. Adamczyk³, I. Aggarwal⁴⁴, M. M. Aggarwal⁴⁴, Z. Ahammed⁶⁵, E. C. Aschenauer⁷, S. Aslam²⁹, J. Atchison² et al. (STAR Collaboration)

J. Atchison², V. Bairathi⁵⁵, X. Bao⁵¹, K. Barish¹², S. Behera²⁸, R. Bellwied²⁵, P. Bhagat³², A. Bhasin³², S. Bhatta⁵⁴, S. R. Bhosale³, J. Bielcik¹⁷, J. Bielcikova⁴², J. D. Brandenburg⁴³, C. Broodo²⁵, X. Z. Cai⁵², H. Caines⁶⁹, M. Calderón de la Barca Sánchez¹⁰, D. Cebra¹⁰, J. Ceska¹⁷, I. Chakaberia³⁶, P. Chaloupka¹⁷, B. K. Chan¹¹, Z. Chang³⁰, A. Chatterjee¹⁹, D. Chen¹², J. Chen⁵¹, J. H. Chen²², Q. Chen²³, Z. Chen⁵¹, J. Cheng⁶⁰, Y. Cheng¹¹, W. Christie⁷, X. Chu⁷, S. Corey⁴³, H. J. Crawford⁹, M. Csanád²⁰, G. Dale-Gau¹⁴, A. Das¹⁷, I. M. Deppner²⁴, A. Deshpande⁵⁴, A. Dhamija⁴⁴, A. Dimri⁵⁴, P. Dixit²⁷, X. Dong³⁶, J. L. Drachenberg², E. Duckworth³³, J. C. Dunlop⁷, J. Engelage⁹, G. Eppley⁴⁶, S. Esumi⁶¹, O. Evdokimov¹⁴, O. Eyser⁷, R. Fatemi³⁴, S. Fazio⁸, Y. Feng⁴⁵, E. Finch⁵³, Y. Fisyak⁷, F. A. Flor⁶⁹, C. Fu³¹, T. Fu⁵¹, C. A. Gagliardi⁵⁷, T. Galatyuk¹⁸, T. Gao⁵¹, F. Geurts⁴⁶, N. Ghimire⁵⁶, A. Gibson⁶⁴, K. Gopal²⁸, X. Gou⁵¹, D. Grosnick⁶⁴, A. Gu²⁶, A. Gupta³², A. Hamed⁵, X. Han⁴³, S. Harabasz¹⁸, M. D. Harasty¹⁰, J. W. Harris⁶⁹, H. Harrison-Smith³⁴, L. B. Havener⁶⁹, X. H. He³¹, Y. He⁵¹, N. Herrmann²⁴, L. Holub¹⁷, C. Hu⁶², Q. Hu³¹, Y. Hu³⁶, H. Huang⁴¹, H. Z. Huang¹¹, S. L. Huang⁵⁴, T. Huang¹⁴, Y. Huang⁶⁰, Y. Huang¹³, T. J. Humanic⁴³, M. Isshiki⁶¹, W. W. Jacobs³⁰, A. Jalotra³², C. Jena²⁸, A. Jentsch⁷, Y. Ji³⁶, J. Jia^54,7, C. Jin⁴⁶, N. Jindal⁴³, X. Ju⁴⁸, E. G. Judd⁹, S. Kabana⁵⁵, D. Kalinkin³⁴, K. Kang⁶⁰, D. Kapukchyan¹², K. Kauder⁷, D. Keane³³, A. Khanal⁶⁷, Y. V. Khyzhniak⁴³, D. P. Kikoła⁶⁶, J. Kim⁷, D. Kincses²⁰, I. Kisel²¹, A. Kiselev⁷, A. G. Knospe³⁷, J. Kołaś⁶⁶, B. Korodi⁴³, L. K. Kosarzewski⁴³, L. Kumar⁴⁴, M. C. Labonte¹⁰, R. Lacey⁵⁴, J. M. Landgraf⁷, C. Larson³⁴, J. Lauret⁷, A. Lebedev⁷, J. H. Lee⁷, Y. H. Leung²⁴, C. Li¹³, D. Li⁴⁸, H-S. Li⁴⁵, H. Li⁶⁸, H. Li²³, W. Li⁴⁶, X. Li⁴⁸, X. Li⁴⁸, Y. Li⁶⁰, Z. Li⁴⁹, Z. Li⁴⁸, X. Liang¹², Y. Liang³³, R. Licenik^42,17, T. Lin⁵¹, Y. Lin²³, M. A. Lisa⁴³, C. Liu³¹, G. Liu⁴⁹, H. Liu¹³, L. Liu¹³, Z. Liu¹³, T. Ljubicic⁴⁶, O. Lomicky¹⁷, R. S. Longacre⁷, E. M. Loyd¹², T. Lu³¹, J. Luo⁴⁸, X. F. Luo¹³, L. Ma²², R. Ma⁷, Y. G. Ma²², N. Magdy⁵⁸, D. Mallick⁶⁶, R. Manikandhan²⁵, S. Margetis³³, C. Markert⁵⁹, O. Matonoha¹⁷, O. Mezhanska¹⁷, K. Mi¹³, S. Mioduszewski⁵⁷, B. Mohanty⁴⁰, B. Mondal⁴⁰, M. M. Mondal⁴⁰, I. Mooney⁶⁹, J. Mrazkova^42,17, M. I. Nagy²⁰, C. J. Naim⁵⁴, A. S. Nain⁴⁴, J. D. Nam⁵⁶, M. Nasim²⁷, H. Nasrulloh⁴⁸, D. Neff¹¹, J. M. Nelson⁹, M. Nie⁵¹, G. Nigmatkulov¹⁴, T. Niida⁶¹, T. Nonaka⁶¹, G. Odyniec³⁶, A. Ogawa⁷, S. Oh⁵⁰, K. Okubo⁶¹, B. S. Page⁷, S. Pal¹⁷, A. Pandav³⁶, A. Panday²⁷, A. K. Pandey³¹, T. Pani⁴⁷, A. Paul¹², S. Paul⁵⁴, D. Pawlowska⁶⁶, C. Perkins⁹, J. Pluta⁶⁶, B. R. Pokhrel⁵⁶, I. D. Ponce Pinto⁶⁹, M. Posik⁵⁶, S. Prodhan²⁸, T. L. Protzman³⁷, A. Prozorov¹⁷, V. Prozorova¹⁷, N. K. Pruthi⁴⁴, M. Przybycien³, J. Putschke⁶⁷, Z. Qin⁶⁰, H. Qiu³¹, C. Racz¹², S. K. Radhakrishnan³³, A. Rana⁴⁴, R. L. Ray⁵⁹, R. Reed³⁷, C. W. Robertson⁴⁵, M. Robotkova^42,17, M. A. Rosales Aguilar³⁴, D. Roy⁴⁷, P. Roy Chowdhury⁶⁶, L. Ruan⁷, A. K. Sahoo²⁷, N. R. Sahoo²⁸, H. Sako⁶¹, S. Salur⁴⁷, S. S. Sambyal³², J. K. Sandhu³⁷, S. Sato⁶¹, B. C. Schaefer³⁷, N. Schmitz³⁸, F-J. Seck¹⁸, J. Seger¹⁶, R. Seto¹², P. Seyboth³⁸, N. Shah²⁹, P. V. Shanmuganathan⁷, T. Shao²², M. Sharma³², N. Sharma²⁷, R. Sharma²⁸, S. R. Sharma²⁸, A. I. Sheikh³³, D. Shen⁵¹, D. Y. Shen³¹, K. Shen⁴⁸, S. Shi¹³, Y. Shi⁵¹, F. Si⁴⁸, J. Singh⁵⁵, S. Singha³¹, P. Sinha²⁸, M. J. Skoby^6,45, N. Smirnov⁶⁹, Y. Söhngen²⁴, Y. Song⁶⁹, T. D. S. Stanislaus⁶⁴, M. Stefaniak⁴³, Y. Su⁴⁸, M. Sumbera⁴², X. Sun³¹, Y. Sun⁴⁸, B. Surrow⁵⁶, M. Svoboda^42,17, Z. W. Sweger¹⁰, A. C. Tamis⁶⁹, A. H. Tang⁷, Z. Tang⁴⁸, T. Tarnowsky³⁹, J. H. Thomas³⁶, A. R. Timmins²⁵, D. Tlusty¹⁶, T. Todoroki⁶¹, D. Torres Valladares⁴⁶, S. Trentalange¹¹, P. Tribedy⁷, S. K. Tripathy⁶⁶, T. Truhlar¹⁷, B. A. Trzeciak¹⁷, O. D. Tsai^11,7, C. Y. Tsang^33,7, Z. Tu⁷, J. Tyler⁵⁷, T. Ullrich⁷, D. G. Underwood^4,64, G. Van Buren⁷, J. Vanek⁷, I. Vassiliev²¹, F. Videbæk⁷, S. A. Voloshin⁶⁷, G. Wang¹¹, J. S. Wang²⁶, J. Wang⁵¹, K. Wang⁴⁸, X. Wang⁵¹, Y. Wang⁴⁸, Y. Wang¹³, Y. Wang⁶⁰, Z. Wang⁵¹, A. J. Watroba³, J. C. Webb⁷, P. C. Weidenkaff²⁴, G. D. Westfall³⁹, D. Wielanek⁶⁶, H. Wieman³⁶, G. Wilks¹⁴, S. W. Wissink³⁰, R. Witt⁶³, C. P. Wong⁷, J. Wu¹³, J. Wu⁶², X. Wu¹¹, X. Wu⁴⁸, B. Xi²², Z. G. Xiao⁶⁰, G. Xie⁶², W. Xie⁴⁵, H. Xu²⁶, N. Xu¹³, Q. H. Xu⁵¹, Y. Xu⁵¹, Y. Xu¹³, Z. Xu³³, Z. Xu¹¹, G. Yan⁵¹, Z. Yan⁵⁴, C. Yang⁵¹, Q. Yang⁵¹, S. Yang⁴⁹, Y. Yang^1,41, Z. Ye⁴⁹, Z. Ye³⁶, L. Yi⁵¹, Y. Yu⁵¹, H. Zbroszczyk⁶⁶, W. Zha⁴⁸, C. Zhang²², D. Zhang⁴⁹, J. Zhang⁵¹, S. Zhang¹⁵, W. Zhang⁴⁹, X. Zhang³¹, Y. Zhang³¹, Y. Zhang⁴⁸, Y. Zhang⁵¹, Y. Zhang²³, Z. Zhang⁷, Z. Zhang¹⁴, F. Zhao³⁵, J. Zhao²², M. Zhao⁷, S. Zhou¹³, Y. Zhou¹³, X. Zhu⁶⁰, M. Zurek^4,7, and M. Zyzak²¹ (STAR Collaboration)

¹Academia Sinica, Taipei 115201
²Abilene Christian University, Abilene, Texas 79699
³AGH University of Krakow, FPACS, Cracow 30-059, Poland
⁴Argonne National Laboratory, Argonne, Illinois 60439
⁵American University in Cairo, New Cairo 11835, Egypt
⁶Ball State University, Muncie, Indiana, 47306
⁷Brookhaven National Laboratory, Upton, New York 11973
⁸University of Calabria and INFN-Cosenza, Rende 87036, Italy
⁹University of California, Berkeley, California 94720
¹⁰University of California, Davis, California 95616
¹¹University of California, Los Angeles, California 90095
¹²University of California, Riverside, California 92521
¹³Central China Normal University, Wuhan, Hubei 430079
¹⁴University of Illinois at Chicago, Chicago, Illinois 60607
¹⁵Chongqing University, Chongqing 401331
¹⁶Creighton University, Omaha, Nebraska 68178
¹⁷Czech Technical University in Prague, FNSPE, Prague 115 19, Czech Republic
¹⁸Technische Universität Darmstadt, Darmstadt 64289, Germany
¹⁹National Institute of Technology Durgapur, Durgapur 713209, India
²⁰ELTE Eötvös Loránd University, Budapest, Hungary H-1117
²¹Frankfurt Institute for Advanced Studies FIAS, Frankfurt 60438, Germany
²²Fudan University, Shanghai, 200433
²³Guangxi Normal University, Guilin, 541004
²⁴University of Heidelberg, Heidelberg 69120, Germany
²⁵University of Houston, Houston, Texas 77204
²⁶Huzhou University, Huzhou, Zhejiang 313000
²⁷Indian Institute of Science Education and Research (IISER), Berhampur 760010, India
²⁸Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India
²⁹Indian Institute Technology, Patna, Bihar 801106, India
³⁰Indiana University, Bloomington, Indiana 47408
³¹Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu 730000
³²University of Jammu, Jammu 180001, India
³³Kent State University, Kent, Ohio 44242
³⁴University of Kentucky, Lexington, Kentucky 40506-0055
³⁵Lanzhou University, Lanzhou 730000
³⁶Lawrence Berkeley National Laboratory, Berkeley, California 94720
³⁷Lehigh University, Bethlehem, Pennsylvania 18015
³⁸Max-Planck-Institut für Physik, Munich 80805, Germany
³⁹Michigan State University, East Lansing, Michigan 48824
⁴⁰National Institute of Science Education and Research, HBNI, Jatni 752050, India
⁴¹National Cheng Kung University, Tainan 70101
⁴²Nuclear Physics Institute of the CAS, Rez 250 68, Czech Republic
⁴³The Ohio State University, Columbus, Ohio 43210
⁴⁴Panjab University, Chandigarh 160014, India
⁴⁵Purdue University, West Lafayette, Indiana 47907
⁴⁶Rice University, Houston, Texas 77251
⁴⁷Rutgers University, Piscataway, New Jersey 08854
⁴⁸University of Science and Technology of China, Hefei, Anhui 230026
⁴⁹South China Normal University, Guangzhou, Guangdong 510631
⁵⁰Sejong University, Seoul, 05006, South Korea
⁵¹Shandong University, Qingdao, Shandong 266237
⁵²Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800
⁵³Southern Connecticut State University, New Haven, Connecticut 06515
⁵⁴State University of New York, Stony Brook, New York 11794
⁵⁵Instituto de Alta Investigación, Universidad de Tarapacá, Arica 1000000, Chile
⁵⁶Temple University, Philadelphia, Pennsylvania 19122
⁵⁷Texas A&M University, College Station, Texas 77843
⁵⁸Texas Southern University, Houston, Texas 77004
⁵⁹University of Texas, Austin, Texas 78712
⁶⁰Tsinghua University, Beijing 100084
⁶¹University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
⁶²University of Chinese Academy of Sciences, Beijing, 101408
⁶³United States Naval Academy, Annapolis, Maryland 21402
⁶⁴Valparaiso University, Valparaiso, Indiana 46383
⁶⁵Variable Energy Cyclotron Centre, Kolkata 700064, India
⁶⁶Warsaw University of Technology, Warsaw 00-661, Poland
⁶⁷Wayne State University, Detroit, Michigan 48201
⁶⁸Wuhan University of Science and Technology, Wuhan, Hubei 430065
⁶⁹Yale University, New Haven, Connecticut 06520

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Phys. Rev. D 112, 012003 – Published 7 July, 2025

DOI: https://doi.org/10.1103/r5jw-lwhg

Abstract

The STAR Collaboration reports precise measurements of the longitudinal double-spin asymmetry, $A_{L L}$ , for dijet production with at least one jet at intermediate pseudorapidity $0.8 < η_{jet} < 1.8$ in polarized proton-proton collisions at a center-of-mass energy of 200 GeV. This study explores partons scattered with a longitudinal momentum fraction ( $x$ ) from 0.01 to 0.5, which are predominantly characterized by interactions between high- $x$ valence quarks and low- $x$ gluons. The results are in good agreement with previous measurements at 200 GeV with improved precision and are found to be consistent with the predictions of global analyses that find the gluon polarization to be positive. In contrast, the negative gluon polarization solution from the JAM Collaboration is found to be strongly disfavored.

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Phys. Rev. D 112, 012003– Published 7 July, 2025

Vol. 112, Iss. 1 — 1 July 2025

Received 2 December 2024
Accepted 15 May 2025

DOI: https://doi.org/10.1103/r5jw-lwhg

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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Precision measurement of the longitudinal double-spin asymmetry for dijet production at intermediate pseudorapidity in polarized $p p$ collisions at $\sqrt{s} = 200 GeV$

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Precision measurement of the longitudinal double-spin asymmetry for dijet production at intermediate pseudorapidity in polarized pp collisions at s=200 GeV

Abstract

Physics Subject Headings (PhySH)

Article Text

References (62)

Precision measurement of the longitudinal double-spin asymmetry for dijet production at intermediate pseudorapidity in polarized $p p$ collisions at $\sqrt{s} = 200 GeV$