NEGATIVE BINOMIAL FITS TO MULTIPLICITY DISTRIBUTIONS FROM CENTRAL 16O+Cu COLLISIONS AT 14.6 A GeV/c AND THEIR IMPLICATION FOR “INTERMITTENCY”

Abstract

The method of normalized factorial moments has been used extensively to study the fluctuations in pseudorapidity of charged particle multiplicity as a function of the interval δη. Experience in analyzing the data from light and heavy ion collisions in terms of distributions rather than moments suggests that conventional fluctuations of multiplicity and transverse energy can be well described by gamma or Negative Binomial Distributions (NBD). Multiplicity distributions from central (ZCAL) collisions of 16 O+Cu at 14.6 A GeV/c have been analyzed by the E802 collaboration as a function of the interval δη≥0.1 in the range 1.2≤η≤2.2. Excellent fits to NBD were obtained in all δη bins. The k parameter of the NBD fit exhibits a steep linear increase with the δη interval, which due to the well known property of the NBD under convolution, indicates that the multiplicity distributions in adjacent bins of pseudorapidity δη~0.1 are largely statistically independent. This result explains and demystifies “intermittency.”