New Insights into Global Spin Alignment of Vector Mesons Using Relativistic Heavy-Ion Collisions from STAR

In these proceedings, we present new measurements from STAR of the global spin alignment(${\rho }_{00}$) of $\phi$ mesons in Au+Au collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 19.6, 14.6 GeV using BES-II data and of $J\mathrm{/}\psi$ mesons in isobar collisions ${}_{44}^{96}\mathrm{R}\mathrm{u}+{}_{44}^{96}\mathrm{R}\mathrm{u}$ and ${}_{40}^{96}\mathrm{Z}\mathrm{r}+{}_{40}^{96}\mathrm{Z}\mathrm{r}$ at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 200 GeV. The energy-dependent spin alignment for $\phi$ mesons from BES-II data is consistent with that published from BES-I and showcases a significant improvement in precision. We performed a new measurement assessing the rapidity dependence of $\phi$ meson ${\rho }_{00}$, and our findings are consistent with theoretical predictions. The global spin alignment of $J\mathrm{/}\psi$ mesons with respect to first order event plane aligns with a value of $1\mathrm{/}3$ within the statistical error. Additionally, we discuss the procedure of measuring the global spin alignment of ${\rho }^0$ mesons at RHIC and provide the projection for errors.