Observation of a Gamma Transition Induced in a Target Nucleus by Stopping Pions

Abstract

Evidence is given for the excitation of the 482-keV state in a tantalum target by stopping pions. The yield relative to a pionic x-ray transition is found to depend on target thickness. Several mechanisms for the excitation of the state are discussed. It appears that at least part of the excitation may be due to production of neutrons in the pion absorption process followed by inelastic scattering of the neutrons elsewhere in the target.