The transverse spin transfer from polarized protons to Λ and Λ¯ hyperons is expected to provide sensitivity to the transversity distribution of the nucleon and to the transversely polarized fragmentation functions. We report the first measurement of the transverse spin transfer to Λ and Λ¯ along the polarization direction of the fragmenting quark, DTT, in transversely polarized proton-proton collisions at √s = 200 GeV with the STAR detector at RHIC. The data correspond to an integrated luminosity of 18 pb−1 and cover the pseudorapidity range |η| < 1.2 and transverse momenta pT up to 8 GeV/c. The dependence on pT and η are presented. The DTT results are found to be comparable with a model prediction and are also consistent with zero within uncertainties.
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Funded by SCOAP3.
This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S.National Science Foundation, the Ministry of Education and Science of the Russian Federation, Natural Science Foundation of China, Chinese Academy of Science, the Ministry of Science and Technology of China, the Major State Basic Research Development Program in China(No. 2014CB845406) and the Chinese Ministry of Education, the National Research Foundation of Korea,Czech Science Foundation and Ministry of Education,Youth and Sports of the Czech Republic, Department of Atomic Energy and Department of Science and Technology of the Government of India, the National Science Centre of Poland, the Ministry of Science, Education and Sports of the Republic of Croatia, RosAtom of Russia and German Bundesministerium fur Bildung, Wissenschaft, Forschung and Technologie (BMBF) and the Helmholtz Association.
Adam, J.; Adamczyk, L.; Adkins, James K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Barish, K.; Bassill, A. J.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A. V.; Fatemi, Renee H.; and Ramachandran, Suvarna, "Transverse Spin Transfer to Λ and Λ¯ Hyperons in Polarized Proton-Proton Collisions at √s = 200 GeV" (2018). Physics and Astronomy Faculty Publications. 632.