  Some properties of the rho vector meson are calculated within the
Nambu-Jona-Lasinio model, including processes that go beyond the random phase
approximation. To classify the higher order contributions, we adopt $1/N_c$ as
expansion parameter. In particular, we evaluate the leading order contributions
to the $\rho \rightarrow \pi \pi$ decay width, obtaining the value $\Gamma =
118$ MeV, and to the shift of the rho mass which turns out to be lowered by 64
MeV with respect to its RPA value. A set of model parameters is determined
accordingly.

High Energy Physics - Phenomenology