Absorption of Negative Pions in Deuterium: Parity of the Pion

Abstract

The reaction ${\ensuremath{\pi}}^{\ensuremath{-}}+d\ensuremath{\rightarrow}2n$ has been observed by detecting the two neutrons in coincidence with slow negative mesons incident on a liquid deuterium target. The observed angular correlation of the two neutrons confirms the identification of the process. The process is therefore not forbidden, and this fact may be used to establish the odd relative parity of the pion and the nucleon.