Spin alignment measurements of K$^{∗0}$ vector mesons with ALICE at the LHC

We present the recent spin alignment measurements of K$^{*0}$ vector mesons at mid-rapidity ($|y|$$<$0.5) in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV and 5.02 TeV and in pp collisions at $\sqrt{s}$ = 13 TeV, performed with the ALICE detector at the LHC. Spin alignment measurements of K$^{*0}$ vector mesons are performed with respect to the production plane and second order event plane. The measured value of the spin density matrix element $\rho_{00}$ is below 1/3 at low transverse momentum ($p_{\mathrm{T}}$) ($p_{\mathrm{T}}$$<$1.8 GeV/$c$) and consistent with 1/3 at high $p_{\mathrm{T}}$ in mid-central Pb-Pb collisions. The $\rho_{00}$ values from both production plane and event plane are similar and no energy dependence is observed for measured $\rho_{00}$ values at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV and 5.02 TeV within the uncertainties. $\rho_{00}$ also shows a centrality dependence with maximum deviation from 1/3 at mid-central collisions. $\rho_{00}$ values for K$^{*0}$ in pp collisions at $\sqrt{s}$ = 13 TeV and for K$_{\mathrm{S}}^{0}$ in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV in the 20-40\% centrality are consistent with 1/3 in the whole measured $p_{\mathrm{T}}$ interval, which ranges from 0.0$<$$p_{\mathrm{T}}$$<$10 GeV/$c$ and 0.0$<$$p_{\mathrm{T}}$$<$5 GeV/$c$ respectively.