Orateur
Description
Despite extensive measurements on the production yields of light nuclei in heavy-ion collisions, a consensus on their formation mechanism remains elusive. In contrast to normal nuclei, hypernuclei carries strangeness and can offer an additional dimension for such studies. In particular, the hypertriton $^{3}_{\Lambda}\rm{H}$, a bound state consisting of a proton, neutron and $\Lambda$ hyperon, is the lightest known hypernucleus with a very small binding energy of $\sim$130 keV. Currently, published measurements of the $^{3}_{\Lambda}\rm{H}$ yield are scarce and are limited to very low ($\sqrt{s_{NN}} < 5$ GeV) or very high collision energies ($\geq 200$ GeV). Precise measurements on the energy dependence of $^{3}_{\Lambda}\rm{H}$ production will give invaluable information on hypernuclei production mechanisms due to its unique intrinsic properties.
In this presentation, we will present comprehensive measurements of the collision energy dependence of $^{3}_{\Lambda}\rm{H}$ transverse momentum $p_T$ and $p_T$-integrated yield at mid-rapidity in Au$+$Au collisions at ten collision energies between $3$ and $27$ GeV. It is found that thermal model calculations under-predict the $^{3}_{\Lambda}\rm{H}$ yield and the $^{3}_{\Lambda}\rm{H}/\Lambda$ ratio by a factor of $\sim$2 in the reported energy region, while coalescence calculations are closer to data. We will also present the mean $p_T$ of $^{3}_{\Lambda}\rm{H}$ as a function of collision energy. The mean $p_T$ of $^{3}_{\Lambda}\rm{H}$ is observed to be lower than the Blast-Wave expectation using the same freeze-out parameters from light hadrons. These observations suggest that similar to light nuclei, hypertritons are formed at a later stage than light hadrons possibly through nucleon/hyperon coalescence during these collisions.
