ALICE charming take on strangeness enhancement in pp collisions

CERN

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Published online: 17 April 2026

Abstract

Understanding strangeness enhancement in proton-proton (pp) collisions at the LHC is a challenge for hadronization models. Recent observations indicate that a substantial fraction of the detected Ω⁻ baryons may originate from the decay of charm baryons, e.g. from Ω_c⁰ → Ω⁻ + π⁺. However, the Ω_c⁰ production cross section, as well as branching ratios in different Ω_c⁰ decay channels, are unknown, preventing an exact estimation of the contribution of baryons coming from charm-hadron decays. In this work, the first measurement of the fraction of Ω⁻ baryons originating from heavy hadron decays in pp collisions at √s = 13.6 TeV, performed by the ALICE collaboration, is presented. This result is enabled by the new ALICE Inner Tracking System, which allows for the tracking of the Ω⁻ baryon prior to its decay. By studying the evolution of the fraction of Ω⁻ coming from heavy hadron decays and by comparing it with the existing models, the role of heavy hadron production as a driver of strangeness enhancement is explored.