Stopping-Power Differences Between Positive and Negative Pions at Low Velocities

Abstract

Measurements of grain densities of stopping ${\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}$ mesons in emulsion show that, in the velocity interval $0.051<\ensuremath{\beta}<0.178$, the energy-loss rates of ${\ensuremath{\pi}}^{+}$ mesons exceed that of the ${\ensuremath{\pi}}^{\ensuremath{-}}$ by amounts of 0 to 60 MeV/cm. The reported range differences between positive and negative particles are satisfactorily accounted for by the results of this experiment.