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Muhammad Ibrahim Abdulhamid, Bassam Aboona, Jaroslav Adam, Leszek Adamczyk, J. R. Adams, Ishu Aggarwal, Madan Mohan Aggarwal, Zubayer Ahammed, E. derson, D. M. Alpatov, Elke Caroline Aschenauer, Sameer Aslam, J. Atchison, Vipul Bairathi, W. Baker, Jonathan Gonzalo Ball Cap, Kenneth Barish, Rene Bellwied, P. Bhagat, Anju Bhasin, S. Bhatta, Jaroslav Bielčík, Jana Bielčíková, James D. Brandenburg, Xiang-Zhou Cai, Helen Louise Caines, Manuel Calderón de la Barca Sánchez, Daniel A. Cebra, Jakub Češka, Irakli Chakaberia, Petr Chaloupka, B. K. Chan, Z. Chang, A. Chatterjee, D. Chen, J. Chen, J. H. Chen, Z. Chen, J. Cheng, Y. Cheng, Subikash Choudhury, William Christie, X. Chu, Henry J. Crawford, Máté Csanád, G. Dale-Gau, A. Das, M. Daugherity, Ingo Martin Deppner, A. Dhamija, L. Di Carlo, Lidia Didenko, P. Dixit, X. Dong, James Lucus Drachenberg, E. Duckworth, James C. Dunlop, Jon M. Engelage, Geary Wareham Eppley, ShinIchi Esumi, Olga Y. Evdokimov, A. Ewigleben, Kjeld Oleg Eyser, Renee H. Fatemi, Salvatore Fazio, C. J. Feng, Yicheng Feng, Evan Finch, Yuri V. Fisyak, F. A. Flor, C. Fu, Carl A. Gagliardi, Tetyana Galatyuk, Frank Geurts, N. Ghimire, Adam Gibson, Krishan Gopal, X. Gou, David P. Grosnick, Anik Gupta, Włodzimierz Guryn, Ahmed M. Hamed, Y. Han, S. Harabasz, M. D. Harasty, John W. Harris, H. Harrison-Smith, W. He, X. H. He, Y. He, Norbert Herrmann, Lukáš Holub, C. Hu, Q. Hu, Y. Hu, H. Huang, Huan Zhong Huang, Shengli Huang, T. Huang, X. Huang, Y. Huang, Y. Huang, Thomas J. Humanic, D. Isenhower, M. Isshiki, William W. Jacobs, A. Jalotra, Chitrasen Jena, Alexander Jentsch, Yuanjing Ji, J. Jia, C. Jin, X. Ju, Eleanor G. Judd, Sonia Kabana, M. L. Kabir, Skipper Kagamaster, Dmitry Kalinkin, K. Kang, David Kapukchyan, Declan Keane, Matthew Kelsey, Y. V. Khyzhniak, Daniel P. Kikoła, B. Kimelman, D. Kincses, Ivan Kisel, A. Kiselev, Anders Garritt Knospe, H. S. Ko, Leszek Krzysztof Kosarzewski, L. Kramarik, Lokesh Kumar, Shyam Kumar, R. Kunnawalkam Elayavalli, Roy Alphanso Lacey, Jeffery M. Landgraf, Jerome Lauret, Alexei Lebedev, J. H. Lee, Y. H. Leung, N. Lewis, C. Li, W. Li, X. Li, Y. Li, Y. Li, Z. Li, X. Liang, Y. Liang, Robert Licenik, T. Lin, Michael A. Lisa, C. Liu, F. Liu, G. Liu, H. Liu, H. Liu, L. Liu, T. Liu, X. Liu, Y. Liu, Z. Liu, Tonko A. Ljubicic, William Joseph Llope, O. Lomicky, Ronald S. Longacre, E. M. Loyd, T. Lu, N. S. Lukow, X. F. Luo, L. Ma, R. Ma, Yu-Gang Ma, Niseem Magdy Abdelwahab Abdelrahman, Dukhishyam Mallick, Spyridon Margetis, Christina Markert, Howard S. Matis, Joel Anthony Mazer, G. McNamara, K. Mi, Saskia Mioduszewski, Bedangadas Mohanty, Mriganka Mouli Mondal, Isaac A. Mooney, A. Mukherjee, M. I. Nagy, A. S. Nain, J. D. Nam, M. Nasim, D. Neff, John M. Nelson, Daniel B. Nemes, M. Nie, Grigory A. Nigmatkulov, Takafumi Niida, R. Nishitani, Toshihiro Nonaka, G. Odyniec, Akio Ogawa, Saehanseul Oh, K. Okubo, Brian S. Page, R. Pak, Jinjin Pan, A. Pandav, Ashutosh Kumar Pandey, T. Pani, A. Paul, Bogdan Pawlik, Diana Pawłowska, Chris Perkins, Jan Marian Pluta, B. R. Pokhrel, Matthew Posik, Tristan Protzman, V. Prozorova, Navneet Kumar Pruthi, Mariusz Przybycien, Jörn H. Putschke, Z. Qin, H. Qiu, Amilkar Quintero, Cameron Racz, Sooraj Krishnan Radhakrishnan, N. Raha, Robert L. Ray, Rosi Jan Reed, H. G. Ritter, C. W. Robertson, M. Robotkova, M. A. Rosales Aguilar, D. Roy, P. Roy Chowdhury, L. Ruan, A. K. Sahoo, Nihar Ranjan Sahoo, H. Sako, Sevil Salur, S. Sato, William B. Schmidke, Norbert Schmitz, F-J. Seck, Janet Elizabeth Seger, Richard Seto, Peter Seyboth, N. Shah, Prashanth V. Shanmuganathan, T. Shao, M. Sharma, Natasha Sharma, R. Sharma, S. R. Sharma, Ashik Ikbal Sheikh, D. Y. Shen, K. Shen, S. S. Shi, Y. Shi, Q. Y. Shou, F. Si, J. Singh, Subhash Singha, P. Sinha, M. J. Skoby, Nikolai Smirnov, Yannick Söhngen, Y. Song, B. Srivastava, T. D. Shirvel Stanislaus, Maria Stefaniak, David J. Stewart, Blair Stringfellow, Y. Su, Alexandre Alarcon do Passo Suaide, Michal Šumbera, C. Sun, X. Sun, Y. Sun, Y. Sun, Bernd Surrow, Z. W. Sweger, Paweł Szymański, A. Tamis, Aihong Tang, Z. Tang, Terence J. Tarnowsky, James H. Thomas, Anthony Robert Timmins, David Tlusty, Takahito Todoroki, C. A. Tomkiel, Stephen Trentalange, Robert E. Tribble, Prithwish Tribedy, T. Truhlar, Barbara Antonina Trzeciak, Oleg D. Tsai, C. Y. Tsang, Zhoudunming Tu, J. Tyler, Thomas Ullrich, David G. Underwood, Isaac Upsal, Gene Van Buren, Jan Vanek, Iouri Vassiliev, Veronica Verkest, Flemming Videbæk, Sergei Voloshin, F. Wang, G. Wang, J. S. Wang, X. Wang, Y. Wang, Y. Wang, Y. Wang, Z. Wang, Jason C. Webb, Philipp Weidenkaff, Gary D. Westfall, D. Wielanek, Howard Wieman, G. Wilks, Scott W. Wissink, Richard Witt, J. Wu, J. Wu, X. Wu, Y. Wu, B. Xi, Z. G. Xiao, Guannan Xie, W. Xie, H. Xu, N. Xu, Q. H. Xu, Y. Xu, Y. Xu, Z. Xu, Z. Xu, G. Yan, Z. Yan, C. Yang, Q. Yang, S. Yang, Y. Yang, Z. Ye, Z. Ye, L. Yi, K. Yip, Y. Yu, Hanna Paulina Zbroszczyk, W. Zha, C. Zhang, D. Zhang, J. Zhang, S. Zhang, W. Zhang, X. Zhang, Y. Zhang, Y. Zhang, Y. Zhang, Z. J. Zhang, Z. Zhang, Z. Zhang, F. Zhao, J. Zhao, M. Zhao, C. Zhou, J. Zhou, S. Zhou, Y. Zhou, X. Zhu, M. Zurek, Maksym Zyzak

• In relativistic heavy-ion collisions, a global spin polarization, PH, of Λ and Λ¯ hyperons along the direction of the system angular momentum was discovered and measured across a broad range of collision energies and demonstrated a trend of increasing PH with decreasing sNN−−−√. A splitting between Λ and Λ¯ polarization may be possible due to their different magnetic moments in a late-stage magnetic field sustained by the quark-gluon plasma which is formed in the collision. The results presented in this study find no significant splitting at the collision energies of sNN−−−√=19.6 and 27 GeV in the RHIC Beam Energy Scan Phase II using the STAR detector, with an upper limit of PΛ¯−PΛ<0.24% and PΛ¯−PΛ<0.35%, respectively, at a 95% confidence level. We derive an upper limit on the naïve extraction of the late-stage magnetic field of B<9.4⋅1012 T and B<1.4⋅1013 T at sNN−−−√=19.6 and 27 GeV, respectively, although more thorough derivations are needed. Differential measurements of PH were performed with respect to collision centrality, transverse momentum, and rapidity. With our current acceptance of |y|<1 and uncertainties, we observe no dependence on transverse momentum and rapidity in this analysis. These results challenge multiple existing model calculations following a variety of different assumptions which have each predicted a strong dependence on rapidity in this collision-energy range.