The results of an investigation of the correlation between the mass (M) and the transverse momentum (p/sub T/) of multipion systems produced in pp collisions at 102 and 400 GeV/c indicate that, for fixed M, p/sub T/ distributions are only weakly dependent on the incident energy, as well as on the charge and multiplicity of the produced system. The dependence of on M is much stronger and is similar to that measured for discrete hadronic states.