Hyperon polarization along the beam direction relative to the second and third harmonic event planes in isobar collisions at $\sqrt{s_{NN}}$ = 200 GeV
Nuclear Experiment
2023-11-21 v2
Abstract
The polarization of and hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at = 200 GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagree with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.
Keywords
Cite
@article{arxiv.2303.09074,
title = {Hyperon polarization along the beam direction relative to the second and third harmonic event planes in isobar collisions at $\sqrt{s_{NN}}$ = 200 GeV},
author = {STAR Collaboration and M. I. Abdulhamid and B. E. Aboona and J. Adam and J. R. Adams and G. Agakishiev and I. Aggarwal and M. M. Aggarwal and Z. Ahammed and A. Aitbaev and I. Alekseev and D. M. Anderson and A. Aparin and S. Aslam and J. Atchison and G. S. Averichev and V. Bairathi and W. Baker and J. G. Ball Cap and K. Barish and P. Bhagat and A. Bhasin and S. Bhatta and I. G. Bordyuzhin and J. D. Brandenburg and A. V. Brandin and X. Z. Cai and H. Caines and M. Calderón de la Barca Sánchez and D. Cebra and J. Ceska and I. Chakaberia and B. K. Chan and Z. Chang and A. Chatterjee and D. Chen and J. Chen and J. H. Chen and Z. Chen and J. Cheng and Y. Cheng and S. Choudhury and W. Christie and X. Chu and H. J. Crawford and G. Dale-Gau and A. Das and M. Daugherity and T. G. Dedovich and I. M. Deppner and A. A. Derevschikov and A. Dhamija and L. Di Carlo and P. Dixit and X. Dong and J. L. Drachenberg and E. Duckworth and J. C. Dunlop and J. Engelage and G. Eppley and S. Esumi and O. Evdokimov and A. Ewigleben and O. Eyser and R. Fatemi and S. Fazio and C. J. Feng and Y. Feng and E. Finch and Y. Fisyak and F. A. Flor and C. Fu and T. Gao and F. Geurts and N. Ghimire and A. Gibson and K. Gopal and X. Gou and D. Grosnick and A. Gupta and A. Hamed and Y. Han and M. D. Harasty and J. W. Harris and H. Harrison-Smith and W. He and X. H. He and Y. He and C. Hu and Q. Hu and Y. Hu and H. Huang and H. Z. Huang and S. L. Huang and T. Huang and X. Huang and Y. Huang and Y. Huang and T. J. Humanic and D. Isenhower and M. Isshiki and W. W. Jacobs and A. Jalotra and C. Jena and Y. Ji and J. Jia and C. Jin and X. Ju and E. G. Judd and S. Kabana and M. L. Kabir and D. Kalinkin and K. Kang and D. Kapukchyan and K. Kauder and D. Keane and A. Kechechyan and M. Kelsey and B. Kimelman and A. Kiselev and A. G. Knospe and H. S. Ko and L. Kochenda and A. A. Korobitsin and P. Kravtsov and L. Kumar and S. Kumar and R. Kunnawalkam Elayavalli and R. Lacey and J. M. Landgraf and A. Lebedev and R. Lednicky and J. H. Lee and Y. H. Leung and N. Lewis and C. Li and W. Li and X. Li and Y. Li and Y. Li and Z. Li and X. Liang and Y. Liang and T. Lin and C. Liu and F. Liu and G. Liu and H. Liu and H. Liu and L. Liu and T. Liu and X. Liu and Y. Liu and Z. Liu and T. Ljubicic and W. J. Llope and O. Lomicky and R. S. Longacre and E. M. Loyd and T. Lu and N. S. Lukow and X. F. Luo and V. B. Luong and L. Ma and R. Ma and Y. G. Ma and N. Magdy and D. Mallick and S. Margetis and H. S. Matis and J. A. Mazer and G. McNamara and K. Mi and N. G. Minaev and B. Mohanty and M. M. Mondal and I. Mooney and D. A. Morozov and A. Mudrokh and M. I. Nagy and A. S. Nain and J. D. Nam and M. Nasim and D. Neff and J. M. Nelson and D. B. Nemes and M. Nie and G. Nigmatkulov and T. Niida and R. Nishitani and L. V. Nogach and T. Nonaka and G. Odyniec and A. Ogawa and S. Oh and V. A. Okorokov and K. Okubo and B. S. Page and R. Pak and J. Pan and A. Pandav and A. K. Pandey and Y. Panebratsev and T. Pani and P. Parfenov and A. Paul and C. Perkins and B. R. Pokhrel and M. Posik and T. Protzman and N. K. Pruthi and J. Putschke and Z. Qin and H. Qiu and A. Quintero and C. Racz and S. K. Radhakrishnan and N. Raha and R. L. Ray and H. G. Ritter and C. W. Robertson and O. V. Rogachevsky and M. A. Rosales Aguilar and D. Roy and L. Ruan and A. K. Sahoo and N. R. Sahoo and H. Sako and S. Salur and E. Samigullin and S. Sato and W. B. Schmidke and N. Schmitz and J. Seger and R. Seto and P. Seyboth and N. Shah and E. Shahaliev and P. V. Shanmuganathan and T. Shao and M. Sharma and N. Sharma and R. Sharma and S. R. Sharma and A. I. Sheikh and D. Shen and D. Y. Shen and K. Shen and S. S. Shi and Y. Shi and Q. Y. Shou and F. Si and J. Singh and S. Singha and P. Sinha and M. J. Skoby and Y. Söhngen and Y. Song and B. Srivastava and T. D. S. Stanislaus and D. J. Stewart and M. Strikhanov and B. Stringfellow and Y. Su and C. Sun and X. Sun and Y. Sun and Y. Sun and B. Surrow and D. N. Svirida and Z. W. Sweger and A. Tamis and A. H. Tang and Z. Tang and A. Taranenko and T. Tarnowsky and J. H. Thomas and D. Tlusty and T. Todoroki and M. V. Tokarev and C. A. Tomkiel and S. Trentalange and R. E. Tribble and P. Tribedy and O. D. Tsai and C. Y. Tsang and Z. Tu and J. Tyler and T. Ullrich and D. G. Underwood and I. Upsal and G. Van Buren and A. N. Vasiliev and V. Verkest and F. Videbæk and S. Vokal and S. A. Voloshin and F. Wang and G. Wang and J. S. Wang and J. Wang and X. Wang and Y. Wang and Y. Wang and Y. Wang and Z. Wang and J. C. Webb and P. C. Weidenkaff and G. D. Westfall and H. Wieman and G. Wilks and S. W. Wissink and J. Wu and J. Wu and X. Wu and X. Wu and Y. Wu and B. Xi and Z. G. Xiao and G. Xie and W. Xie and H. Xu and N. Xu and Q. H. Xu and Y. Xu and Y. Xu and Z. Xu and Z. Xu and G. Yan and Z. Yan and C. Yang and Q. Yang and S. Yang and Y. Yang and Z. Ye and Z. Ye and L. Yi and K. Yip and Y. Yu and W. Zha and C. Zhang and D. Zhang and J. Zhang and S. Zhang and W. Zhang and X. Zhang and Y. Zhang and Y. Zhang and Y. Zhang and Y. Zhang and Z. J. Zhang and Z. Zhang and Z. Zhang and F. Zhao and J. Zhao and M. Zhao and C. Zhou and J. Zhou and S. Zhou and Y. Zhou and X. Zhu and M. Zurek and M. Zyzak},
journal= {arXiv preprint arXiv:2303.09074},
year = {2023}
}
Comments
6 pages, 5 figures, Published in Physical Review Letters