Scattering of 10-30 Mev Negative Pions by Hydrogen

Abstract

Fifty-seven ${\pi }^{-}-p$ scattering events in the energy range 10-30 Mev have been observed in a hydrogen bubble chamber. The $S$-wave scattering length $\frac{1}{3}{\eta }^{-1\mathrm{}}(2\mathrm{}{\alpha }_1+{\alpha }_3)=0.077\mathrm{}\pm 0.011$ is found to give the best fit to the data assuming ${\alpha }_{13}={\alpha }_{31}={\alpha }_{11}=0\mathrm{}$, ${\alpha }_{33}=0.235\mathrm{}{\eta }^3$. This result is combined with the results of other low-energy scattering experiments to give estimates of ${\alpha }_1$ and ${\alpha }_3$.