Measurements on the production and properties of light hypernuclei at STAR

Abstract

The hyperon-nucleon ($Y$-$N$) interaction, an important ingredient for the nuclear equation-of-state (EoS), remains poorly constrained. Precise measurements of hypernucei intrinsic properties and production yields in heavy-ion collisions are crucial for the understanding of their production mechanisms and the strength of the $Y$-$N$ interaction. Thanks to the high statistics data taken from the STAR BES II program, a series of hypernuclei measurements are carried out at low energies. In these proceedings, we present the kinematic and centrality dependence of light hypernuclei production yields and strangeness population factor ($S_3$, $S_4$) in Au+Au collisions at $\sqrt{s_{\rm NN}}=$ 3 GeV. We also report the energy dependence of $^{3}_{\Lambda}{\rm H}$ yields and $S_3$ at mid-rapidity from 3 to 27 GeV Au+Au collisions. Precise measurements of $^{4}_{\Lambda}{\rm He}$ lifetime and $^{3}_{\Lambda}{\rm H}$ branching ratio are also reported. These results are compared with model calculations and physics implications are discussed.