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

Abstract: Measured multiplicity distributions of primary charged particles produced in the forward rapidity region of the $proton-proton$ ($pp$) collisions at the centre-of-mass energy, $\sqrt {s}$ = 7 TeV at the Large Hadron Collider (LHC) have been analyzed in terms of the Negative Binomial Distribution (NBD) function. Like the multiplicity distributions in the mid-rapidity region for the $pp$ collisions at $\sqrt {s}$ = 7 TeV, the distributions for the minimum bias events in the forward region also are better described with the superposition of two-NBDs, 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.