rho-omega mixing in relativistic heavy-ion collisions
  We show that even moderate excess of neutrons over protons in nuclear matter, such as in ${}^{208} Pb$, can lead to large $\rho$-$\omega$ mixing at densities of the order of twice the nuclear saturation density and higher. The typical mixing angle is of the order of $10^o$. The mixing may result in noticeable shifts of the positions and widths of resonances. We also analyze temperature effects and find that temperatures up to 50 MeV have practically no effect on the mixing. 
Wojciech Broniowski, Wojciech Florkowski (INP Cracow)