# Online Strangeness in Quark Matter Conference 2021

May 17 – 22, 2021
US/Eastern timezone

## Quark coalescence model for spin alignments of vector mesons $\phi$ and $K^{\ast 0}$

May 19, 2021, 9:50 AM
20m
Room B (Zoom)

### Room B

#### Zoom

zoom co-host: Klaus Dehmelt https://stonybrook.zoom.us/j/98548694974
Theory talk

### Speaker

Dr Xin-Li Sheng (Central China Normal University)

### Description

We propose an improved quark coalescence model with spin degrees of freedom for vector mesons by spin density matrix in phase space. This model allows us to estimate spin alignments of vector mesons using polarizations of quarks. We propose that a significant positive deviation from 1/3 of the spin density matrix element $\rho_{00}$ for the $\phi$ meson may attribute to the electric part of the mean vector $\phi$ field generated in heavy ion collisions. Meanwhile, a negative deviation of $\rho_{00}$ for the $K^{\ast 0}$ meson may come from the electric part of the vorticity tensor field. The difference between spin alignments of $\phi$ and $K^{\ast 0}$ is due to the large mass ratio of strange quarks to light quarks. These results should be tested by a detailed and comprehensive simulation of vorticity tensor fields and vector $\phi$ fields in heavy ion collisions.

### Primary authors

Dr Xin-Li Sheng (Central China Normal University) Prof. Qun Wang (University of Science and Technology of China) Lucia Oliva (Institute for Theoretical Physics (ITP), Frankfurt am Main) Dr Xin-Nian Wang (Lawrence Berkeley National Lab. (US))