Bose-Einstein correlations of same-sign charged pions in the forward region in $pp$ collisions at $\sqrt{s}$ = 7 TeV

TL;DR

This paper investigates Bose-Einstein correlations among same-sign charged pions produced in proton-proton collisions at 7 TeV, revealing how correlation strength and source size depend on particle multiplicity.

Contribution

It provides the first detailed measurement of Bose-Einstein correlation parameters in the forward region at LHC energies, including their dependence on charged-particle multiplicity.

Findings

Correlation radius increases with multiplicity

Chaoticity parameter decreases with multiplicity

Enhancement observed in like-sign pion pairs at small momentum difference

Abstract

Bose-Einstein correlations of same-sign charged pions, produced in proton-proton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the form of an enhancement of pairs of like-sign charged pions with small four-momentum difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source is investigated, determining both the correlation radius and the chaoticity parameter. The measured correlation radius is found to increase as a function of increasing charged-particle multiplicity, while the chaoticity parameter is seen to decrease.