In this paper we present a model for three nucleon pion absorption based on the assumption that pion absorption on three nucleons is a one-step process. In the assumption that the square of the effective matrix element is proportional to the probability that three nucleons are contained inside a certain volume V, this model is equal to the Fermi statistical model. The construction of the volume V is different from the Fermi model. Very good agreement between this simple model and experimental data for the energy dependence of the three-nucleon pion absorption cross section on ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ opens a new possibility for the explanation of multinucleon effects in pion absorption.

• Received 10 February 1994

DOI:https://doi.org/10.1103/PhysRevC.50.2224