Multiplicity distributions in the forward rapidity region in proton-proton collisions at the Large Hadron Collider

Measured multiplicity distributions of primary charged particles produced in the forward rapidity region of the proton-proton (pp) collisions at the center-of-mass energy, root s = 7 TeV, at the LHC have been analyzed in terms of the negative binomial distribution function. Like the multiplicity distributions in the midrapidity region for the pp collisions at root s = 7 TeV, the distributions for the minimum bias events in the forward region are also better described with the superposition of two negative binomail distributions, as proposed by a two-component model of particle production from two processes, the soft and the hard. However, the multiplicity distribution for the "hard-QCD'' events in a large pseudorapidity window does not oblige the two-component model.