Production of (Anti-)(Hyper)nuclei in Pb–Pb Collisions Measured with ALICE at the LHC

Abstract

In high-energy heavy-ion collisions nuclei and hypernuclei emerge from the hot and dense fireball formed in the reaction region. Thanks to its excellent particle identification and momentum measurement performance, the ALICE detector allows for the identification of deuterons, tritons, 3 He and 4 He and the corresponding anti-nuclei. This is achieved via the measurement of their specific energy loss in the Time Projection Chamber and the velocity measurement by the Time-Of-Flight detector. Moreover, thanks to the Inner Tracking System capability to separate primary from secondary vertices, it is possible to identify (anti-)hypertriton through the mesonic weak decay 3 Λ H → ( 3 He + π − ). The direct decay time measurement of (anti-)hypertriton is difficult, but the excellent determination of primary and decay vertices, i.e. of the decay length, allows for the measurement of mean lifetime via an exponential fit of the proper decay time distribution. Results on the measurement of the hypertriton mean lifetime will be shown. Plans for the future LHC Run2 and Run3, with the expected improvements in the statistics and precision, will also be presented.