Bose enhancement and the ridge

TL;DR

This paper demonstrates that Bose enhancement in a hadronic wave function naturally causes long-range azimuthal correlations, known as the ridge, in particle production during high-energy collisions, using the Color Glass Condensate framework.

Contribution

It explicitly shows how Bose enhancement of gluons in the projectile leads to the ridge effect in high-energy hadronic collisions within the CGC approach.

Findings

Bose enhancement causes azimuthal collimation of particle correlations.

The ridge arises from gluon correlations in the projectile wave function.

The approach uses the projectile density matrix in the CGC framework.

Abstract

We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.