Abstract
We report the transverse single-spin asymmetries of J/ψ production at forward and backward rapidity, 1.2<|y|<2.2, as a function of J/ψ transverse momentum (pT) and Feynman-x (xF). The data analyzed were recorded by the PHENIX experiment at the Relativistic Heavy Ion Collider in 2015 from p+p, p+Al, and p+Au collisions with transversely polarized proton beams at sNN=200 GeV. At this collision energy, single-spin asymmetries for heavy-flavor particle production of p+p collisions provide access to the spin-dependent gluon distribution and higher-twist correlation functions inside the nucleon, such as the gluon Qiu-Sterman and trigluon correlation functions. Proton+nucleus collisions offer an excellent opportunity to study nuclear effects on the correlation functions. The data indicate a positive asymmetry at the two-standard-deviation level in the p+p data for 2 GeV/c<pT<10 GeV/c at backward rapidity and negative asymmetries at the two-standard-deviation level in the p+Au data for pT<2 GeV/c at both forward and backward rapidity, while in p+Al collisions the asymmetries are consistent with zero within the range of experimental uncertainties.
| Original language | English |
|---|---|
| Article number | 012006 |
| Journal | Physical Review D |
| Volume | 98 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 1 2018 |
Funding
We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We acknowledge support from the Medium Energy Nuclear Physics Program in the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (U.S.), Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan), Conselho Nacional de Desenvolvimento Cient\u00EDfico e Tecnol\u00F3gico and Funda\u00E7\u00E3o de Amparo \u00E0 Pesquisa do Estado de S\u00E3o Paulo (Brazil), Natural Science Foundation of China (People\u2019s Republic of China), Croatian Science Foundation and Ministry of Science and Education (Croatia), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique, Commissariat \u00E0 l\u2019\u00C9nergie Atomique, and Institut National de Physique Nucl\u00E9aire et de Physique des Particules (France), Bundesministerium f\u00FCr Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), J. Bolyai Research Scholarship, EFOP, the New National Excellence Program (\u00DANKP), NKFIH, and OTKA (Hungary), Department of Atomic Energy and Department of Science and Technology (India), Israel Science Foundation (Israel), Basic Science Research Program through NRF of the Ministry of Education (Korea), Physics Department, Lahore University of Management Sciences (Pakistan), Ministry of Education and Science, Russian Academy of Sciences, Federal Agency of Atomic Energy (Russia), VR and Wallenberg Foundation (Sweden), the U.S. Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, the Hungarian American Enterprise Scholarship Fund, the U.S.-Hungarian Fulbright Foundation, and the U.S.-Israel Binational Science Foundation.