The Problem of Mass: Mesonic Bound States Above image Original Research Article

By extending the Bielefeld LGS (Lattice Gauge Simulation) color singlet interaction, 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. This result indicates a smooth phase transition at Tc, at which from above the masses and couplings of mesons vanish à la Brown-Rho scaling. We discuss that our scenario successfully explains the STAR (STAR Collaboration) ρ0/π− ratio in Au-Au peripheral collisions at RHIC.