Exotic Behavior of Heavy-Flavored Meson Matter
  In this work, we study the thermodynamic behavior of heavy-flavored meson matter in the framework of $(\sigma,\omega)$-meson-exchange model in relativistic mean field theory. We find a decreasing of the effective masses of $D$ and $B$ mesons as the temperature increases. By using the effective mass and maximum value of dissociation temperatures available from lattice QCD, the masses of the bound states $D \bar{D}$ and $B \bar{B}$ are estimated in 2 MeV for both molecules. For the $B$-meson matter, the pressure presents an exotic behavior, being negative for temperatures above 6.6 times the deconfinement transition temperature $T_c$. In addition, the ratio of pressure to energy density is similar to the value predicted for systems that behave as dark energy matter. 
L. M. Abreu, E. S. Nery and R. Rodrigues da Silva
hep-ph nucl-th