Two-body Pion Absorption on ${}^{3}He$ at Threshold

Abstract

It is shown that a satisfactory explanation of the ratio of the rates of the reactions ${}^{3}He({\pi }^{-},nn)$ and ${}^{3}He({\pi }^{-},np)$ for stopped pions is obtained once the effect of the short range two-nucleon components of the axial charge operator for the nuclear system is taken into account. By employing realistic models for the nucleon-nucleon interaction in the construction of these components of the axial charge operator, the predicted ratios agree with the empirical value to within 10-20\%.

Comments: 19, UHPHYDOR-94-2