Nuclear Equation of State (EoS) from High-Energy Scattering Data

Description
On the basis of the S-matrix formulation of statistical physics, suggested by Dashen, Ma and Bernstein, supplied by high-energy hadron scattering data, an equation of state p(T) is derived. Asymptotically (T>>m_p), the obtained EoS behaves as p(T)~aT^6, different from the that in the ideal gas, ~T^4, predicted by perturbative quantum chromodynamics (QCD). The coefficient a in front of T^6 has the dimension [GeV]^(-2), typical of an inverse mass square; it is related to the parameters of high-energy hadron scattering and was calculated by the present author. Physically this means that the hot and dense nuclear matter may not be asymptotically free as predicted by perturbative QCD, instead residual forces between quarks and gluons may survive, with masses of the exchanged particles of the order of 1 GeV. The account for the non-asymptotic contributions results in the EoS p(T)=cT^-bT^5+aT^6 with known (positive) coefficients a, b and c. The second (pre-asymptotic) term produces a local metastable state with negative pressure. The presence of metastable states with negative temperature is known also from a modification of the bag EoS (by Kallman at al.). It has far-reaching consequences for the hadronic stage in the evolution of the universe by producing exponential expansion of the universe previous or during the confining phase transition.