Charged kaon femtoscopic correlations in pp collisions at $\sqrt{s}=7$ TeV

TL;DR

This study measures charged kaon correlations in proton-proton collisions at 7 TeV, revealing trends in femtoscopic radii with multiplicity and transverse momentum, and comparing these to pion correlations in similar and heavy-ion collisions.

Contribution

It provides the first detailed measurement of charged kaon femtoscopic correlations in pp collisions at LHC energies, highlighting differences from pion correlations at high multiplicities.

Findings

Femtoscopic radii increase with multiplicity.

Radii decrease with increasing transverse momentum.

Charged kaon radii are larger than pion radii at high multiplicity.

Abstract

Correlations of two charged identical kaons (${\rm K}^{\rm ch}{\rm K}^{\rm ch}$) are measured in pp collisions at $\sqrt{s}=7$~TeV by the ALICE experiment at the Large Hadron Collider (LHC). One-dimensional ${\rm K}^{\rm ch}{\rm K}^{\rm ch}$ correlation functions are constructed in three multiplicity and four transverse momentum ranges. The ${\rm K}^{\rm ch}{\rm K}^{\rm ch}$ femtoscopic source parameters $R$ and $\lambda$ are extracted. The ${\rm K}^{\rm ch}{\rm K}^{\rm ch}$ correlations show a slight increase of femtoscopic radii with increasing multiplicity and a slight decrease of radii with increasing transverse momentum. These trends are similar to the ones observed for $\pi \pi$ and ${\rm K}^0_{\rm s}{\rm K}^0_{\rm s}$ correlations in pp and heavy-ion collisions. However at high multiplicities, there is an indication that the one-dimensional correlation radii for charged kaons are larger than those for pions in contrast to what was observed in heavy-ion collisions at RHIC.