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 AA 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 an energy dependence of hadron transverse-mass spectra which is similar to that observed in heavy-ion collisions. A comparison with other scenarios is given. The text was submitted by the authors in English.