Color reconnection as a possible mechanism of intermittency in the emission spectra of charged particles in PYTHIA-generated high-multiplicity pp collisions at energies available at the CERN Large Hadron Collider

摘要

Nonstatistical fluctuation in pseudorapidity (eta), azimuthal (phi), and pseudorapidity-azimuthal (eta-phi) distribution spectra of primary particles of PYTHIA Monash (default) generated pp events at root s = 2.76,7 and 13 TeV have been studied using the scaled factorial moment technique. A weak intermittent type of emission could be realized for minimum-bias (MB) pp events in chi(eta-phi) space and a much stronger intermittency could be observed in high-multiplicity (HM) pp events in all chi(eta), chi(phi), and chi(eta-phi) spaces at all the studied energies. For HM pp events, at a particular energy, the intermittency index alpha(q) is found to be largest in two-dimensional chi(eta-phi) space and least in chi(eta) space, and no center of mass energy dependence of a q could be observed. The anomalous dimensions d(q) are observed to be increased with the order of the moment q, suggesting a multifractal nature of the emission spectra of various studied events. While, the coefficient lambda(q) is found to decrease monotonically with the order of the moment q for two-dimensional analysis of MB pp events as well as for one-dimensional analysis of HM pp events, a clear minimum in lambda(q) values could be observed from the two-dimensional HM pp data analysis. For PYTHIA Monash generated sets of data, the strength of the intermittency is found to vary significantly with the variation of the strength of the color reconnection (CR) parameter, i.e., reconnection range RR, for RR = 0.0, 1.8 and 3.0, thereby, establishing a strong connection between the CR mechanism and the observed intermittent type of emission of primary charged particles of the studied high-multiplicity pp events.