The problem of mass: Mesonic bound states above Tc

We discuss the problem of mass, noting that meson masses decrease with increasing scale as the dynamically generated condensate of “soft glue” is melted (Brown/Rho scaling). We then extend the Bielefeld LGS (Lattice Gauge Simulation) color-singlet interaction computed for heavy quarks in a model-dependent way by including the Ampére law velocity-velocity interaction. Parameterizing the resulting interaction in terms of effective strength of the potential and including screening, we find that the masses of π, σ, ρ and A1 excitations, 32 degrees of freedom in all, go to zero (in the chiral limit) as T→Tc essentially independently of the input quark (thermal) masses in the range of 1-2 GeV, calculated also in Bielefeld. We discuss other LGS which show q¯q bound states, which we interpret as our chirally restored mesons, for T>Tc.