Target dependence of clan model parameters at Dubna energy-chaotic pion production

Abstract

A detailed study of clan model parameters and their target dependence has been carried out in the light of void probability scaling for heavy (AgBr) and light (CNO) groups of targets present in the nuclear emulsion using 22Ne (at an incident momentum of 4.1 GeV/c), 28Si (at an incident momentum of 4.5 GeV/c), 16O (at an incident momentum of 4.5 GeV/c) and 32S (at an incident momentum of 4.5 GeV/c) projectiles. The variation of scaled rap-gap probability with the single moment combination has been studied for all of the interactions. The experimental points are found to lie approximately on the NBD curve for all of the interactions, indicating a scaling behavior. According to the two-source model of particle production, in the case of 32S–AgBr interactions at 4.5 GeV/c, the pion production mechanism has been found to be almost chaotic. On the contrary, for all of the other interactions at 4.1–4.5 GeV/c, pion production is predominantly chaotic. Average clan multiplicities () for all of the interactions are found to increase with the increase in the pseudo-rapidity interval Δη. The values of for the AgBr target are larger than those for the CNO target. The average number of particles per clan () increases initially with the increase in pseudo-rapidity interval. An approximate saturation of the values of is observed for 22Ne and 16O projectiles around Δη = 6. With the increase in projectile size, the saturation of seems to be wiped out. It can also be observed from the tables that for a particular target the average number of particles per clan () increases with the increase in the size of the projectile nucleus. A comparison with the results of the SPS data has also been presented.