Saturation models of HERA DIS data and inclusive hadron distributions in p+p collisions at the LHC

TL;DR

This paper uses saturation models derived from HERA data to predict inclusive hadron distributions in proton-proton collisions at the LHC, showing agreement with experimental results and implications for multi-particle correlations.

Contribution

It introduces and applies several saturation models based on HERA data to analyze LHC p+p collision data, highlighting their predictive power and sensitivity to model parameters.

Findings

Models fit HERA data well

Predictions agree with LHC multiplicity distributions

Implications for multi-particle correlation interpretation

Abstract

Unintegrated gluon distributions sensitive to the transverse spatial distribution of gluons in the proton are extracted from data on exclusive and diffractive final states at HERA in the dipole approach. These unintegrated gluon distributions can be used to compute inclusive hadron production in p+p collisions at the LHC. In this paper, we consider a number of saturation models with differering dynamical assumptions that give good fits to the available HERA data. We apply these models to study the rapidity and transverse momentum dependence of the LHC data up to $\sqrt{s} = 7$ TeV. We examine the sensitivity of these results to parameters that are not constrained by the HERA data and comment on similarities and differences with previous work. We compute the n-particle inclusive multiplicity distribution and show that the LHC p+p results are in agreement with predictions for multi-particle production in the Color Glass Condensate approach. This result has significant ramifications for the interpretation of multi-particle correlations in high multiplicity events at the LHC.