Isospin Dependence of Pion Absorption on a Pair of Nucleons

Abstract

The relative cross sections for the $2N+\ensuremath{\pi}\ensuremath{\rightarrow}2N$ reactions were determined where the initial two nucleons are in a relative $s$ state, and coupled either to isospin zero or to one. This information is extracted from two-nucleon coincidence measurements of the (${\ensuremath{\pi}}^{+}$, $2p$) and the (${\ensuremath{\pi}}^{\ensuremath{-}}$, $\mathrm{pn}$) reactions on targets of $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$.