We study the factorial moments (Fq), the factorial cumulants (Kq) and the ratio of Kq to Fq (Hq = Kq=Fq) in pp/pp collisions using an updated approach, in which the multiplicity distribution is related to the eikonal function. The QCD inspired eikona
l model adopted contains contributions of quark-quark, quark-gluon and gluon-gluon interactions. Our work shows that the approach can reproduce the collision energy dependence of the Fq moments, correctly predicts that the first minimum of the Hq lies around q = 5 and qualitatively reproduces the oscillations of the Hq moments, as shown in the experimental data and predicted by QCD at preasymptotic energy. The result of this study seems to indicate that the Hq oscillations are manifestation of semihard component in the multiparticle production process. Predictions for multiplicity distribution and Hq moments at the LHC energy of 14 TeV are presented.
We study the impact parameter dependence of inelasticity in the framework of an updated geometrical model for multiplicity distribution. A formula in which the inelasticity is related to the eikonal is obtained. This framework permits a calculation o
f the multiplicity distributions as well as the inelasticity once the eikonal function is given. Adopting a QCD inspired parametrization for the eikonal, in which the gluon-gluon contribution dominates at high energy and determines the asymptotic behavior of the cross sections, we find that the inelasticity decreases as collision energy is increased. Our results predict the KNO scaling violation observed at LHC energies by CMS Collaboration.
