Transverse momentum spectra of hadrons produced in central heavy-ion collisions

In-medium effects of transverse-mass distributions of quarks and gluons are considered assuming a possible local equilibrium for colorless quark objects like mesons and baryons created in central A+A collisions. It is shown that the average square of the transverse momentum for these partons grows and then saturates when the initial energy increases. Within the quark-gluon string model it leads to the energy dependence of hadron transverse mass spectra which is similar to that observed in heavy ion collisions. Comparison with other scenarios is given.