Experimental status on spin polarization in heavy ion collisions at RHIC

In non-central collisions, large angular momentum can be manifested in the form of vorticity in the medium. Due to the spin-orbit coupling, spin directions of particles are aligned with the orbital angular momentum of the system. The global polarization of hyperons has been measured at various collision energies indicating the role of large angular momentum perpendicular to the reaction plane. In addition, the anisotropic flow of the medium can induce a local vorticity. It leads to spin polarization along the beam direction and might have different sensitivity to the relaxation time of the vorticity. The global spin alignment of vector meson can also offer information on the spin-orbit interactions of the QCD medium. In this talk, we will present recent measurements of the spin polarization of hyperons and spin alignment of vector mesons in heavy-ion collisions at RHIC.