K0s-K0s correlations in 7 TeV pp collisions from the ALICE experiment at the LHC

TL;DR

This study measures neutral kaon pair correlations in 7 TeV proton-proton collisions, revealing how femtoscopic source parameters vary with multiplicity and transverse momentum, and extending previous pion correlation findings to higher kT ranges.

Contribution

It provides the first detailed femtoscopic analysis of K0s-K0s correlations in high-energy pp collisions, incorporating a PYTHIA-based model to account for baseline effects.

Findings

Source size increases with multiplicity

Source size decreases with increasing kT

Correlation behavior extends pion results to higher kT

Abstract

Identical neutral kaon pair correlations are measured in 7 TeV pp collisions in the ALICE experiment. K0s-K0s correlation functions are formed in 3 multiplicity X 4 kT bins. The femtoscopic kaon source parameters Rinv and lambda are extracted from these correlation functions by fitting a (femtoscopy) X (PYTHIA) model to them, PYTHIA accounting for the non-flat baseline found in pp collisions. Source parameters are obtained from a fit which includes quantum statistics and final-state interactions of the a0/f0 resonance. K0s-K0s correlations show a systematic increase in Rinv for increasing multiplicity bin and decreasing Rinv for increasing kT bin as seen in pi-pi correlations in the pp system, as well as seen in heavy-ion collisions. Also, K0s-K0s correlations are observed to smoothly extend this pi-pi Rinv behavior for the pp system up to about three times higher kT than the kT range measured in pi-pi correlations.