Temperatures of negative pions in inelastic (d, alpha,C)+ (C,Ta) collisions at 4.2A GeV/c.

Abstract

The slopes of the noninvariant center-of-mass energy spectrum of negative pions in inelastic collisions of d, \ensuremath{\alpha}, C nuclei with C and Ta targets at 4.2A GeV/c are studied. The temperatures of the negative pion are obtained using the Boltzmann distribution. The two-temperature shape of c.m. energy spectra is observed. The values of temperature do not depend significantly both on collision ``centrality'' and on atomic weight of the projectile nuclei. The experimental results are compared with the quark-gluon string model. The influence of resonances and directly produced pions on temperature values is studied.