Global Polarization of (Anti-)Hypertriton in Heavy-Ion Collisions

Particles of non-zero spin produced in non-central heavy-ion collisions are expected to be polarized along the direction perpendicular to the reaction plane because of their spin-orbit interactions in the produced matter, and this has indeed been observed for many hyperons and vector mesons. Here, we show that the hypertriton (³_), which is the lightest hypernucleus, is also polarized in these collisions. Using the coalescence model based on the kinetic freezeout baryons for light (hyper-) nuclei production, we find that the angular distribution of the decay product of polarized ³_ is highly sensitive to the spin configuration of its wavefunction, providing a novel way to determine its spin structure. We also predict the beam energy dependence of ³_ and ³_{} H polarizations in heavy-ion collisions from a few GeV to several TeV based on the measured and polarizations. We further discuss the possibility of studying the spin correlations among nucleons and hyperons in the produced hadronic matter from the measured ³_ polarization in non-central heavy-ion collisions.