Narrow Results

In this paper we have studied the multiplicity distribution of black and grey particles emitted from ¹⁶O–AgBr interactions at 2.1 AGeV and 60 AGeV. We have also calculated the multiplicity moment up to the fifth order for both the interactions and for both kinds of emitted particles. The variation of multiplicity moment with the order number has been investigated. It is seen that in the case of black particles multiplicity moment up to fourth order remains almost constant as energy increases from 2.1 AGeV to 60 AGeV. Fifth order multiplicity moment increases insignificantly with energy. However in the case of grey particles no such constancy of multiplicity moment with energy of the projectile beam is obtained. Later we have extended our study on the basis of Regge–Mueller approach to find the existence of second order correlation during the emission of black as well as the grey particles. The second Mueller moment is found to be positive and it increases as energy increases in the case of black particles. On the contrary in the case of grey particles the second Mueller moment decreases with energy. It can be concluded that as energy increases correlation among the black particles increases. On the other hand with the increase of energy correlation among the grey particles is found to diminish.

A detailed study on the multiplicity characteristics of the slow target fragments emitted in relativistic heavy-ion collisions has been carried out at E_Lab = 3.7A and 200A GeV using ³²S projectile. The beam energy dependence of the black particles produced in the full phase space of ³²S-emulsion (³²S-Em) interactions on the target size in terms of their moments (mean, variance, skewness and kurtosis) is investigated. The various order moments of target fragments emitted in the interactions of ³²S beams with the heavy (AgBr) target nuclei are estimated in the forward (FHS) and backward (BHS) hemispheres. The investigated values of ratio of variance to mean at both energies show that the multiplicity distributions (MDs) are not Poissonian and the strongly correlated emission of target fragments are in the forward directions. The degree of anisotropic fragment emission and nature of correlation among the emitted fragments are investigated. The energy dependence of entropy is examined in both hemispheres. The entropy values normalized to average multiplicity are found to be energy independent. Scaling of MD of black particles produced in these interactions has been studied to verify the validity of scaling hypothesis via two scaling (Koba–Nielsen–Olesen (KNO)-scaling and Hegyi-scaling) functions. A simplified universal function has been used in each scaling to display the experimental data.

Different aspects like multiplicity moments, $D_q$ moments and multiplicity fluctuations in terms of scaled variance of the shower particles has been carried out for central events of ${}^{16}\mathrm{\text{O}}-\mathrm{\text{AgBr}}$, ${}^{22}\mathrm{\text{Ne}}-\mathrm{\text{AgBr}}$ and ${}^{32}\mathrm{\text{S}}-\mathrm{\text{AgBr}}$ interactions at (4.1–4.5) AGeV/c. Comparison of our results with different experimental analysis of central collisions of emulsion data has been performed whenever available.

In this work, a detailed study on the multiplicity characteristics of fast and slow target protons produced in the interactions of 3.3AGeV ${}^{22}\mathrm{\text{Ne}}$ and 3.7AGeV ${}^{24}$Mg projectiles with the heavy emulsion nuclei (AgBr) is performed. The experimental data of the multiplicity distributions (MDs) of gray (fast protons) and black (slow protons) particles are fitted with the negative binomial and Gaussian distributions indicating a reasonable consensus with each. The validity of scaling hypothesis of MDs of gray and black particles is verified by studying two types of scaling functions, Koba–Nielson–Olsen (KNO) scaling and Hegyi scaling. The experimental data are displayed by a simplified universal function in each scaling. An examination of the relationship between the entropy and the average multiplicity is performed. The measurements of the higher-order moments (mean, variance, skewedness and kurtosis) of MDs of proton target fragments are measured. The second Muller moments are calculated as well to investigate the correlation among the fast and slow target protons.