Meson Masses in Nuclear Matter

Mass shifts $\ensuremath{\Delta}m$ of particles in nuclear matter relative to their vacuum values are considered. A general formula relating $\ensuremath{\Delta}m(E)$ ( $E$ is the particle energy) to the real part of the forward particle-nucleon scattering amplitude $\mathrm{Re}f(E)$ is presented and its applicability domain is formulated. The $\ensuremath{\rho}$-meson mass shift in nuclear matter is calculated at $2\ensuremath{\lesssim}{E}_{\ensuremath{\rho}}\ensuremath{\lesssim}7\mathrm{GeV}$ for transversally and longitudinally polarized $\ensuremath{\rho}$ mesons.