Narrow Results

The dynamical fluctuations inside the quark and antiquark jets are studied using Monte Carlo method. Quark and antiquark jets are identified from the two-jet events in e⁺e^- collisions at 91.2 GeV by checking them at parton level. It is found that the transition point exists inside both of these two kinds of jets. At this point the jets are circular in the transverse plane with respect to the property of dynamical fluctuations. The results are consistent with the fact that the third jet (gluon jet) was historically first discovered in e⁺e^- collisions in the energy region 17–30 GeV.

An attempt is made to study multifractal specific heat from F_q, modified G_q and Takagi moments, which can provide some interesting information about event-by-event fluctuations in heavy-ion collisions at high energies. It is an established fact that constancy of the specific heat (CSH) of solids and gases helps explain thermodynamical behavior of intermittency and multifractality in A–A collisions at different projectile energies. It is worthmentioning that the present paper deals with multifractal specific heat, c, extracted from F_q, modified G_q and Takagi moments for the experimental as well as FRITIOF generated data on 14.5A GeV/c²⁸Si-nucleus interactions. The results obtained using the three approaches are compared for both the data sets. The observed power law behavior reflects self-similar property of the multiparticle production process. The common feature of the multifractal specific heat obtained using the three approaches is that there is no systematic variation in its value for different orders of the moments. Furthermore, the value of c is found to be different for both the data sets and no strong target mass dependence is observed in any of the cases. A noteworthy observation is that a non-zero finite value of the multifractal specific heat may be considered a good signal for the presence of multifractality in the relativistic charged particle multiplicity distribution.

A detailed study of centrality dependence of event-by-event fluctuations of maximum particle density of the produced particles in narrow pseudo-rapidity interval in terms of the scaled variance $\omega$ has been carried out for ${}^{16}$O-emulsion interactions at 4.5AGeV/$c$. Depending on the values of the total charges or sum of the charges of noninteracting projectile fragments, event samples were classified into four centrality classes. Presence of event-by-event fluctuations of maximum particle density is reflected in the multiparticle production process for different centrality classes. The event-by-event fluctuations are found to decrease with the increase of pseudo-rapidity interval. The event-by-event fluctuations are found to decrease with decreasing centrality of collisions. A comparison with the analyzed results of the total disintegration events has also been carried out. Experimental analysis results have been compared with those obtained from the analysis of Monte Carlo simulated (MC-RAND) events in order to extract the dynamical fluctuations.

In this study, we have performed a detailed analysis of genuine pion correlations and fluctuations in terms of the normalized factorial comulant moments of second and third orders, $K_2$ and $K_3$, in case of ${}^{16}$O–AgBr interactions at $60$A and $200$A GeV/c. The experimental results are compared with the predictions of AMPT and UrQMD model simulated events. The UrQMD model reproduces the trends in experimental results but the strength of correlation is much smaller. However, the AMPT model does not also replicate all features of the experimental data. The genuine two-particle and three-particle correlations are found to become weaker with the increase in momentum of the projectile nucleus.