Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This study investigates how the production of K*(892)0 and φ(1020) mesons varies with charged-particle multiplicity in proton-proton collisions at 13 TeV, exploring potential collective effects and resonance modifications in small systems.

Contribution

First measurements of K* and φ meson production as a function of multiplicity in pp collisions at 13 TeV, providing insights into resonance behavior and strangeness production mechanisms.

Findings

Resonance yields and spectra vary with multiplicity.

Comparison with models shows partial agreement.

Evidence of possible collective effects in small systems.

Abstract

Measurements of identified hadrons as a function of the charged-particle multiplicity in pp collisions enable a search for the onset of collective effects in small collision systems. With such measurements, it is possible to study the mechanisms that determine the shapes of hadron transverse momentum ($p_{\rm{T}}$) spectra, to search for possible modifications of the yields of short-lived hadronic resonances due to scattering effects in the hadron-gas phase, and to investigate different explanations for the multiplicity evolution of strangeness production provided by phenomenological models. In this paper, these topics are addressed through measurements of the $\rm{K}^{*}(892)^{0}$ and $\phi(1020)$ mesons at midrapidity in pp collisions at $\sqrt{s}$ = 13 TeV as a function of the charged-particle multiplicity. The results include the $p_{\rm{T}}$ spectra, $p_{\rm{T}}$-integrated yields, mean transverse momenta, and the ratios of the yields of these resonances to those of longer-lived hadrons. Comparisons with results from other collision systems and energies, as well as predictions from phenomenological models, are also discussed.