Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in collisions at is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.
|Journal||Physical review letters|
|Publication status||Published - 2021 Oct 15|
Bibliographical noteFunding Information:
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 also thank D. Pitonyak and S. Yoshida for helpful discussions. We acknowledge support from 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 (USA), Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan), Natural Science Foundation of China (People’s 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 à l’Énergie Atomique, and Institut National de Physique Nucléaire et de Physique des Particules (France), Bundesministerium für Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), J. Bolyai Research Scholarship, EFOP, the New National Excellence Program (ÚNKP), NKFIH, and OTKA (Hungary), Department of Atomic Energy and Department of Science and Technology (India), Israel Science Foundation (Israel), Basic Science Research and SRC (CENuM) Programs through NRF funded by the Ministry of Education and the Ministry of Science and ICT (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 US-Hungarian Fulbright Foundation, and the US-Israel Binational Science Foundation.
Brookhaven National Laboratory Nuclear Physics National Science Foundation National Science Foundation Abilene Christian University Research Foundation for the State University of New York Vanderbilt University Ministry of Education, Culture, Sports, Science and Technology Japan Society for the Promotion of Science National Natural Science Foundation of China Hrvatska Zaklada za Znanost Ministarstvo znanosti i obrazovanja Ministerstvo Školství, Mládeže a T?lovýchovy Centre National de la Recherche Scientifique Commissariat à l’Énergie Atomique et aux Énergies Alternatives Institut National de Physique Nucléaire et de Physique des Particules Bundesministerium für Bildung und Forschung Deutscher Akademischer Austauschdienst Alexander von Humboldt-Stiftung EFOP ÚNKP Nemzeti Kutatási Fejlesztési és Innovációs Hivatal OTKA Department of Atomic Energy, Government of India Israel Science Foundation Basic Science Research SRC National Research Foundation of Korea Lahore University of Management Sciences Ministry of Education and Science of the Russian Federation Russian Academy of Sciences Federal Agency of Atomic Energy of the Russian Federation Vetenskapsrådet Knut och Alice Wallenbergs Stiftelse CRDF Global Hungarian American Enterprise Scholarship Fund Fulbright Association United States-Israel Binational Science Foundation
© 2021 Published by the American Physical Society
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)