摘要
The pseudorapidity distribution of charged particles produced in p-p collisions at 400GeV/c was measured by using the Lexan bubble chamber films offered by the CERN NA27 collaboration.The scaled factorial cumulant moments have been calculated.The results show that the second order cumulants have positive values,while the cumulants of higher order are consistent with zero except for the case with nch≥4 events,where the third-order cumulants have small positive values beyond the statistical uncertainties.From Monte Carlo events with the same single particle spectrum and no correlations,we observed that for broad mixed-multiplicity distributions,a significant part of K2 is coming from the single-particle fluctuation due to the fluctuation multiplicity.
基金
Supported by the National Natural Science Foundation of China.