On Transverse Momentum Spectra Of Negative Pions In C-12+Ta-181 Collisions At 4.2agev/C

We studied the dependences of the experimental transverse momentum spectra of the negative pions, produced in minimum bias C-12+Ta-181 collisions at a momentum of 4.2 GeV/c per nucleon, on the collision centrality and the pion rapidity range. To examine quantitatively, the change in the shape of the pt spectra of pi(-) mesons with the change of collision centrality and the pion rapidity range, all the extracted pt spectra were fitted by the four different functions commonly used for describing the hadron spectra. The extracted values of the spectral temperatures T-1 and T-2 were consistently larger for the pt spectra of p- mesons coming from midrapidity range as compared to those of the negative pions generated in the target and projectile fragmentation regions. The spectral temperatures of the negative pions coming from projectile fragmentation region proved to be larger than the respective temperatures of the negative pions coming from target fragmentation region. The extracted spectral temperatures T-1 and T-2 of the pt spectra of pi(-) mesons were compatible within the uncertainties for the peripheral, semi-central and central C-12+Ta-181 collision events, selected using the number of participant protons. It was observed that Hagedorn and Boltzmann functions are more appropriate for describing the transverse momentum spectra of the negative pions as contrasted to Simple Exponential and Gaussian functions.