Beyond the average: measuring higher moments of the (anti)deuteron multiplicity distribution with ALICE

by Sourav Kundu (CERN)

Tuesday 2 Aug 2022, 11:00 → 12:00 Europe/Zurich

500/1-001 - Main Auditorium (CERN)

Despite two decades of extensive studies, the production of (anti)nuclei in heavy-ion collisions as well as in hadron collisions has not been fully elucidated. The production of (anti)nuclei is usually modelled by two conceptually different theoretical models, the statistical hadronisation model (SHM) and the coalescence model. In the SHM, (anti)nuclei are produced from a locally thermally equilibrated source, while in the coalescence model, (anti)nuclei are formed from the binding of constituent nucleons, which are close in momentum and spatial phase space. In small collision systems (pp, p–Pb), the production yield of loosely bound hypernuclei can be used to distinguish the two production mechanisms due to the large size of hypernuclei compared to the size of the system produced in these collisions. However, both models give a similar prediction of (anti)nuclei production yields in heavy-ion collisions (Pb–Pb). This similarity calls for new experimental observables to decisively discriminate between these two nucleosynthesis models in heavy-ion collisions.

In this talk, we report recent measurements of (anti)nuclei and hypernuclei production in small and heavy-ion collision systems using the ALICE detector. The first measurement of higher-order moments of the antideuteron multiplicity distribution and the correlation of antideuteron with produced antiproton in heavy-ion collisions are also reported. The measurements are compared with the expectations of the SHM and coalescence models. In addition, the correlation volume for baryon quantum numbers within the SHM is calculated through the correlation between event-by-event production of antiproton and antideuteron. These new observables represent an additional testing ground for two nucleosynthesis models.

CERN-LHC-Light-Nuclei_v6.pdf

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