On the possibility of rho-meson condensation in neutron stars
  The possibility of meson condensation in stars and in heavy-ion collisions has been discussed in the past. Here, we study whether rho meson condensation ($\rho^{-}$) can occur in very dense matter and determine the effect of strong magnetic fields on this condensation. We find that rho meson condensates can appear in the core of the neutron star assuming a rho mass which is reduced due to in-medium effects. We find that the magnetic field has a non-negligible effect in triggering condensation. 
Ritam Mallick, Stefan Schramm, Veronica Dexheimer and Abhijit   Bhattacharyya
astro-ph.HE nucl-th