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

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.

Comments: 16 pages, 11 figures; v3: revised version corrects for an error in the p_T distributions. The corrected results further improve agreement with data. The changes do not affect other results in the paper