Effects of ρ-meson width on pion distributions in heavy-ion collisions

The influence of the finite width of rho meson on the pion momentum distribution is studied quantitatively in the framework of the S-matrix approach combined with a blast-wave model to describe particle emissions from an expanding fireball. We find that the proper treatment of resonances which accounts for their production dynamics encoded in data for partial wave scattering amplitudes can substantially modify spectra of daughter particles originating in their two body decays. In particular, it results in an enhancement of the low-p(T) pions from the decays of rho mesons which improves the quantitative description of the pion spectra in heavy ion collisions obtained by the ALICE collaboration at the LHC energy. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.