Spin alignment of K*⁰ measured with ALICE detector at the LHC

A large angular momentum and intense magnetic field are expected to be produced in relativistic heavy-ion collisions at RHIC and LHC. Experimentally the proposed signature is the measurement of the spin alignment of vector mesons like K*⁰ and ϕ. The large angular momentum could lead to the observation of a non-uniform angular distribution of the decay products in the rest frame of the vector meson, with respect to the normal to the production plane (plane defined by the vector meson momentum and the beam axis) or to the reaction plane defined by the impact parameter and the beam axis of the system. The angular distribution allows for the estimation of the spin density matrix element. We present the new results on the spin alignment of K*⁰ vector mesons in Pb-Pb collisions at √s_NN = 2.76 and 5.02 TeV measured with respect to the production and to the event plane as a function of p_T and centrality using the ALICE detector. For null hypothesis, the spin alignment of K*⁰ in pp collisions at √s = 13 TeV and K⁰_S (spin 0) in Pb-Pb collisions at √s_NN = 2.76 TeV have also been studied