Speaker
Description
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 due to spin-orbit coupling in the produced matter, and this has indeed been observed for many hyperons and vector mesons. Here, we show that the hypertriton ($_\Lambda^3$H), 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 $_\Lambda^3$H 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 $_\Lambda^3$H polarizations in heavy-ion collisions from a few to hundreds GeV based on a multi-phase transport model (AMPT) and coalescence model. We further discuss the comparation of the global polarization between hypertriton and hyperon with the energy dependence. These patterns of the global $_\Lambda^3$H polarization are expected to be tested in future experiments.
