Speaker
Description
Hypernuclei, bound states consisting of nucleons and hyperons, provide a unique opportunity to study the hyperon-nucleon ($Y$-$N$) interaction and the role of strangeness in nuclear matter. Because free hyperon targets are unavailable and hyperon–nucleon scattering data are limited, hypernuclei provide an important means of constraining hyperon–nucleon interactions. Measurements of hypernuclei production yields and kinematic distributions can provide valuable constraints on the production mechanisms.
In this talk, we will present the measurements of $A=4$ hypernuclei ($^{4}_{\Lambda}$H and $^{4}_{\Lambda}$He) production from the RHIC-STAR experiment using the fixed-target datasets. The transverse momentum ($p_{\rm T}$) spectra and rapidity dependent yields ($dN/dy$) will be presented for $\sqrt{s_{\rm NN}}$ = 3.0, 3.2, 3.5, and 3.9 GeV Au+Au collisions. The rapidity and collision energy dependence of $dN/dy$ and $\langle p_{\rm T}\rangle$ for $^{4}_{\Lambda}$He will be compared with those of its mirror hypernucleus $^{4}_{\Lambda}$H in 0--40\% central collisions.
Furthermore, theoretical calculations from Thermal-FIST, PHQMD, and the JAM transport model combined with a coalescence afterburner will be compared with the measurements, and the implications for hypernuclei production mechanisms will be discussed.
