Distribution of the number of particles in the final state of hadron-nucleus collisions

TL;DR

This paper discusses how proton-nucleus collisions at the LHC can reveal detailed fluctuations in gluon density, using the color dipole model to connect particle counts to gluon distributions.

Contribution

It introduces a method to relate particle number fluctuations in proton-nucleus collisions to gluon density statistics, supported by numerical calculations.

Findings

Analytical results linking particle counts to gluon distributions.

Preliminary numerical calculations support the analytical framework.

Potential to access gluon fluctuation statistics at the LHC.

Abstract

Recently, Liou, Mueller and Munier have argued that proton-nucleus collisions at the LHC may give access to the full statistics of the event-by-event fluctuations of the gluon density in the proton. Indeed, the number of particles produced in an event in rapidity slices in the fragmentation region of the proton may, under some well-defined assumptions, be directly related to the number of gluons which have a transverse momentum larger than the nuclear saturation scale present in the proton at the time of the interaction with the nucleus. A first calculation of the probability distribution of the number of gluons in a hadron was performed, using the color dipole model. In this talk, we review this proposal, and present preliminary numerical calculations which support the analytical results obtained so far.