Centrality Dependences of Characteristics of Negative Pions in π− +12C Interactions at 40 GeV/c

Abstract

The collision centrality dependences of the mean multiplicities and kinematical characteristics of negative pions produced in п−+12C collisions at 40 GeV/с are investigated. It is obtained that the average values of the partial inelasticity coefficients of negative pions (without “leading” pions) do not depend on the п−+12C collision centrality. It is shown that the normalized transverse momentum distributions, as well as the average values of the transverse momentum of negative pions, do not depend within the uncertainties on the п−+12C collision centrality. The average value of the emission angle of the negative pions was found to increase with the п−+12C collision centrality. The comparison of the normalized emission angle distributions of the negative pions in the peripheral and central п−+12C collisions at 40 GeV/с supported the assumption that such an increase in the average emission angle is likely due to an increase in the number of binary collisions and multiple rescatterings with the п−+12C collision centrality. The obtained experimental findings are reproduced qualitatively well by the Modified FRITIOF model calculations.