Open Access

Esther Bartsch

• The high collision energies reached at the LHC lead to significant production yields of light (anti)hypernuclei in proton–proton (pp), proton–lead (p–Pb) and, in particular, Pb–Pb collisions. The lightest known hypernucleus is the hypertriton, which is a bound state of a proton, a neutron, and a Λ hyperon. It decays weakly with a decay length of a few centimeters. The excellent tracking and particle identification capabilities of the ALICE detector, exploiting the energy loss measurement of the Time Projection Chamber (TPC) and using the Inner Tracking System (ITS) to distinguish between primary and secondary (decay) vertices, allow for the determination of the hypertriton yield across different collision systems, its lifetime, and its binding energy. The latest hypertriton lifetime measurement in Pb–Pb collisions performed in the 2-body decay channel will be presented. This measurement contributes to the solution of the hypertriton lifetime puzzle. In addition, the hypertriton production in different collision systems and at different energies will be compared to model predictions. Due to its low binding energy, and hence to its large size, the hypertriton is the ideal candidate to distinguish between statistical hadronization and coalescence models. With the precision of the presented yield measurements some variants of the aforementioned models can be excluded.