Two-pion Bose-Einstein correlations in pp collisions at $\sqrt{s}=900$ GeV

TL;DR

This paper reports on two-pion Bose-Einstein correlations in proton-proton collisions at 900 GeV, revealing an increase in HBT radius with event multiplicity but no decrease with transverse momentum, contrasting previous findings.

Contribution

First measurement of two-pion correlations at 900 GeV in pp collisions, highlighting differences from higher-energy collision behaviors.

Findings

HBT radius increases with event multiplicity.

No observed decrease of radius with transverse momentum.

Results differ from RHIC and Tevatron observations.

Abstract

We report on the measurement of two-pion correlation functions from pp collisions at $\sqrt{s}=900$ GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the HBT radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at RHIC and at Tevatron, is not manifest in our data.