EXTRACTION OF CLAN MODEL PARAMETERS FROM MULTIPLICITY DISTRIBUTIONS MEASURED IN pp COLLISIONS AT LHC ENERGIES

Abstract

This paper presents the variation of clan model parameters nc and [Formula: see text] with energy for p–p collisions at [Formula: see text] and 2360 GeV using ALICE and CMS as the detectors. The data for multiplicity distribution was reported by the ALICE and CMS collaborations. The values of [Formula: see text] and [Formula: see text] are evaluated from the NBD fit parameters [Formula: see text] and k. Hegyi [Phys. Lett. B274, 214 (1992)] suggested an alternative method for determination of clan model parameters from void probability. A comparison of values obtained from the two methods is also done. A close agreement of values obtained from the two methods was observed for 546 GeV [Formula: see text] collisions. However for LHC data the agreement is not very well. Void probability overestimates the value of [Formula: see text] and underestimates the value of [Formula: see text] compared to that obtained from NBD. [Formula: see text] is found to increase with energy for both ALICE and CMS data. Contrary to the observation at lower energies that [Formula: see text] does not depend on energy, it is found to vary with energy. The variation of [Formula: see text] with energy is more prominent for CMS data. The results are discussed in detail. For CMS data, comparison of the results with the 7000 GeV data is also shown.