Production of strange hadrons in jets and underlying events in pp and p-Pb collisions with ALICE

TL;DR

This study measures strange and multi-strange hadron production in jets and underlying events in pp and p-Pb collisions at the LHC, revealing differences from inclusive spectra and testing PYTHIA 8 predictions.

Contribution

First measurement of multi-strange hadron production in jets and underlying events in pp and p-Pb collisions at the LHC.

Findings

Multi-strange hadron yields in jets are measured for the first time.

Particle spectra in jets are independent of collision system and energy.

Discrepancies between data and PYTHIA 8 for $ ext{Xi}/ ext{Lambda}$ ratios.

Abstract

The production of strange~($K^0_S$, $\Lambda$) and multi-strange~($\Xi$ and $\Omega$) hadrons in jets and underlying events in \pp and \pPb collisions is studied with ALICE at the LHC. Transverse momentum ($p_\rm{T}$) differential density distribution of particles produced in a jet is compared to that of inclusive particle production and that in underlying events. The particle yield ratios of $\Lambda/K^0_S$ and $\Xi/\Lambda$ as a function of $p_\rm{T}$ are also investigated in jets and underlying events.The production of the multi-strange hadrons, $\Xi$ and $\Omega$, and the corresponding ratio in jets and underlying events are measured for the first time. The $p_\rm{T}$-differential density distribution of hadrons associated with hard scattering decreases slower than that for inclusive production. The baryon-to-meson and baryon-to-baryon ratios measured in jets exhibit clear differences from values obtained from the inclusive spectra in the intermediate $p_\rm{T}$ range. The $p_\rm{T}$ distribution of strange hadrons produced in jets is also studied in pp collisions at $\sqrt{s}$ = 13 TeV and 7 TeV and in p-Pb collisions at $\sqrt{s_\rm{NN}}$ = 5.02 TeV. The $p_\rm{T}$ spectra of particle produced in jets are independent of collision systems and collision energies.No apparent collision energy and collision system dependence is observed for the particle yield ratios of $\Lambda/K^0_S$ and $\Xi/\Lambda$ associated with energetic jets. These new results are compared to PYTHIA 8 event generator. The $\Lambda/K^0_S$ ratio are generally reproduced by the model, but large discrepancies between data and PYTHIA simulations are observed for $\Xi/\Lambda$.