Multiplicity distributions in the low x regime in a simple model

Abstract

In this work we introduce small changes in the model proposed by E. Levin and D. Kharzeev for multiplicity distributions of particles produced in proton-proton collisions. We compare the predictions of the model with the available experimental data from the LHC. We also consider the most recent version of the model proposed by E. Gotsman and E. Levin. These two versions of the model give a good description of the measured multiplicity distributions in the central pseudo-rapidity region ($|\eta| < 0.5$). The agreement with data is not so good when we consider the particles measured over a wider pseudo-rapidity interval ($|\eta| < 2.4$). Interestingly, the agreement becomes better when one selects events with higher transverse momentum ($p_T > 500$ MeV).