Measurement of the transverse-momentum fraction of strange hadrons from jet-like correlation structures in pp collisions at s=13 TeV

The first measurements of the average transverse-momentum fraction (⟨ z ⟩) as a function of transverse momentum (p _T) for strange baryons (Λ and Λ‾) and strange mesons (K_S⁰), produced in mini-jets defined through angular correlations in pp collisions at s=13 TeV, are reported by the ALICE Collaboration at the LHC. The observable is obtained using a novel method, where the angular correlation between the strange hadrons and inclusive charged hadrons is weighted by the p _T of correlated particles at small angular distance. As a function of strange particles’ p _T, the results reveal a flat trend for strange mesons and a decreasing trend for strange baryons in the measured p _T region, indicating distinct hadronization mechanisms for K_S⁰ and Λ (Λ‾). The measurements are compared to Monte Carlo models, namely Pythia 8 (with both Monash and Color Rope tunes) and the AMPT (A Multi-Phase Transport) model with string melting. None of these models provides a satisfactory description of the ⟨ z ⟩ distributions at low and intermediate p _T.