DoP Colloquium - Nikola Poljak

Measures extreme values of strangeness enhancement at the LHC
(Nikola Poljak - PMF, Zagreb)

Over the past 15 years, the ALICE Collaboration has investigated strangeness enhancement, one of the known signatures of quark-gluon plasma. When measured as a function of charged-particle multiplicity at midrapidity, this ratio exhibits a
smooth evolution across collision systems and energies, suggesting that strange-hadron production is primarily connected to the overall event activity and is largely insensitive to the initial conditions. In recent studies, ALICE has completed a comprehensive analysis of strange-to-non-strange hadron yield ratios in various systems, extending previous measurements with unprecedented precision over a multiplicity range from ~2 to ~2000 charged particles at midrapidity.

Motivated by the observations in pp collisions, the collaboration has taken a further step towards understanding strangeness-production mechanisms by measuring, for the first time, the event-by-event probability of forming multiple strange particles of the same species. The results are compared with state-of-the-art phenomenological models implemented in widely used Monte Carlo event generators, providing enhanced sensitivity to the underlying dynamics of strangeness production.