${{\mathit \rho}{(770)}}$ RANGE PARAMETER
INSPIRE search
The range parameter $\mathit R$ enters an energy-dependent correction to the width, of the form (1 $+$ $\mathit q{}^{2}_{\mathit r}$ $\mathit R{}^{2}$) $/$ (1 $+$ $\mathit q{}^{2}$ $\mathit R{}^{2}$), where $\mathit q$ is the momentum of one of the pions in the ${{\mathit \pi}}{{\mathit \pi}}$ rest system. At resonance, $\mathit q$ = $\mathit q_{\mathit r}$.
