26th International Symposium on Spin Physics (SPIN2025)

Global tensor polarization of spin-3/2 hadrons and quark spin correlations in relativistic heavy-ion collisions

Not scheduled

20m

Oral Spin in heavy ion collisions Spin in heavy ion collisions

Speaker

Zihan Yu (Shandong University)

Description

The STAR Collaboration results on global spin alignment of vector mesons in heavy-ion collisions [1] reveal that quarks in the quark-gluon plasma (QGP) exhibit not only global polarization[2, 3] but also spin correlations, leading the study on spin effects in heavy-ion collisions to a new climax.

A systematic formalism for describing spin correlations in a system of spin-1/2 particles and their relationships to experimental observables is given in Ref.[4]. This framework is further extended in Ref.[5] to compute the global polarizations of spin-3/2 baryons in relativistic heavy-ion collisions. The calculation results show that the rank-2 and rank-3 tensor polarizations of spin-3/2 baryons reflect local two and three quark spin correlations respectively. A more comprehensive set of results will be published in a forthcoming paper[6].

This report aims to present the relationships between measurable spin-3/2 baryon tensor polarization and quark spin correlations, explore methods to extract these correlations from measurements of successive spin-3/2 baryon decays.

References
[1] M. S. Abdallah et al. [STAR], “Pattern of global spin alignment of ϕ and K∗0 mesons in heavy-ion
collisions,” Nature 614, 244 (2023).
[2] Z. T. Liang and X. N. Wang, “Globally polarized quark-gluon plasma in non-central A+A collisions,”
Phys. Rev. Lett. 94, 102301 (2005).
[3] Z. T. Liang and X. N. Wang, “Spin alignment of vector mesons in non-central A+A collisions,”
Phys. Lett. B 629, 20 (2005).
[4] J. p. Lv, Z. h. Yu, Z. t. Liang, Q. Wang and X. N. Wang, “Global quark spin correlations in
relativistic heavy ion collisions,” Phys. Rev. D 109, 114003 (2024).
[5] Z. Zhang, J. p. Lv, Z. h. Yu and Z. t. Liang, “Global tensor polarization of spin 3/2 hadrons and
quark spin correlations in relativistic heavy ion collisions,” Phys. Rev. D 110, 074019 (2024).
[6] J. p. Lv, Z. h. Yu, Z. t. Liang, “The complete results of global polarization and spin correlation of
hadrons with different spins in relativistic heavy ion collisions,” paper in preparation.