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

Abstract

The first measurements of the average transverse-momentum fraction ($⟨z⟩$) as a function of transverse momentum ($p_{\mathrm{T}}$) for strange baryons ($\Lambda$ and $\bar{\Lambda }$) and strange mesons ($K_{\mathrm{S}}^0$), produced in mini-jets defined through angular correlations in pp collisions at $\sqrt{s}=13$ 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 $p_{\mathrm{T}}$ of correlated particles at small angular distance. As a function of strange particles' $p_{\mathrm{T}}$, the results reveal a flat trend for strange mesons and a decreasing trend for strange baryons in the measured $p_{\mathrm{T}}$ region, indicating distinct hadronization mechanisms for $K_{\mathrm{S}}^0$ and $\Lambda$($\bar{\Lambda }$). 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 $p_{\mathrm{T}}$.

21 pages, 8 captioned figures, 2 tables, authors from page 19, submitted to Phys. Lett. B, figures at http://alice-publications.web.cern.ch/node/13176