The Effect Of Interaction On Multiplicity Of Pions

We study the effect of the interaction among pions on the pion distribution using non-extensive statistics.In the high energy heavy-ion collisions,the yield of pions is the largest among the produced hadrons.So it is significant to study its distribution to understand the physical picture of heavy ion collisions.The interaction among mesons is the strong interaction,which is a long-range interaction as the definition in statistics.We here use the non-extensive statistics to analyze this long-range interaction system.We use the non-extensive parameter to describe the interaction.The stronger the interaction is,the more the parameter deviates from 1.We use the fractal theory,from quark and meson aspect,to analyze this pion system and calculate the corresponding probability and entropy considering the interaction inside pions and that from the environment.The pion system is equivalent from the two aspects.We solve the probability and entropy equations and obtain the non-extensive parameter and transverse momentum spectrum.We consider the conditions at different collision energy and different centralities,and compare our result with the experimental data and AMPT model.We find that the non-extensive parameter ₂decreases and approach to 1 with increasing the centrality and decreasing the yield of mesons.The interaction among pions decreases with the decrease of ₂.Our result is consistent with the experimental data,and is found to be better than the result of AMPT model.