21-22 December 2021
Online meeting
Europe/Kiev timezone

Constraining baryon annihilation in the hadronic phase of heavy-ion collisions via event-by-event fluctuations

22 Dec 2021, 14:30
20m
Online meeting

Online meeting

Oral talk Physics of Nuclei and Elementary Particles Physics of Nuclei and Elementary Particles

Speaker

Oleh Savchuk (Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine)

Description

We point out that the variance of net-baryon distribution normalized by the Skellam distribution baseline, $\kappa_2[B-\bar{B}]/B+\bar{B}$, is sensitive to the possible modification of (anti)baryon yields due to $B\bar{B}$ annihilation in the hadronic phase. The corresponding measurements can thus place stringent limits on the magnitude of the $B\bar{B}$ annihilation and its inverse reaction. We perform Monte Carlo simulations of the hadronic phase in Pb-Pb collisions at the LHC via the recently developed subensemble sampler + UrQMD afterburner and show that the effect survives in net-proton fluctuations, which are directly accessible experimentally. The available experimental data of the ALICE Collaboration on net-proton fluctuations disfavors a notable suppression of (anti)baryon yields in $B\bar{B}$ annihilations predicted by the present version of UrQMD if only global baryon conservation is incorporated. On the other hand, the annihilations improve the data description when local baryon conservation is imposed. The two effects can be disentangled by measuring $\kappa_2[B+\bar{B}]/B+\bar{B}$, which at the LHC is notably suppressed by annihilations but virtually unaffected by baryon number conservation.

Primary author

Oleh Savchuk (Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine)

Co-authors

Dr Volodymyr Vovchenko (Goethe University Frankfurt) Prof. Volker Koch (Lawrence Berkeley National Laboratory) Horst Stoecker (FIAS Goethe Universitaet Frankfurt GSI) Dr Jan Steinheimer (Frankfurt Institute for Advanced Studies)

Presentation Materials