Photon Spectrum in Pion Capture on Tritium

J. A. Bistirlich; S. Cooper; K. M. Crowe; F. T. Shively; E. R. Grilly; J. P. Perroud; R. H. Sherman; H. W. Baer; P. Truöl

doi:10.1103/PhysRevLett.36.942

Photon Spectrum in Pion Capture on Tritium

J. A. Bistirlich, S. Cooper, K. M. Crowe, F. T. Shively, E. R. Grilly, J. P. Perroud, R. H. Sherman, H. W. Baer, and P. Truöl

Phys. Rev. Lett. 36, 942 – Published 19 April 1976

Abstract

The photon spectrum from the pion-capture reaction $π^{-} + {}^{3}H \to 3 n + γ$ was measured with a high-resolution pair spectrometer. The measured branching ratio $\frac{(π^{-} + {}^{3}H \to 3 n + γ)}{(π^{-} + {}^{3}H \to 3 n + γ or 3 n)}$ is (4.5 ± 0.8)%. The shape of the photon spectrum is in satisfactory agreement with theoretical calculations which include final-state interactions among the three neutrons. No evidence for a bound trineutron is found.

Received 29 January 1976

DOI:https://doi.org/10.1103/PhysRevLett.36.942

Authors & Affiliations

J. A. Bistirlich, S. Cooper, K. M. Crowe, and F. T. Shively^*

Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720

E. R. Grilly, J. P. Perroud^†, and R. H. Sherman

Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87545

H. W. Baer^‡

Case Western Reserve University, Cleveland, Ohio 44106

P. Truöl

Physik-Institut der Universität, Zürich, Switzerland

^*Part of this work was done while at Los Alamos Scientific Laboratory.
^†Visitor from Institut de Physique Nucléaire, Université de Lausanne, Lausanne, Switzerland.
^‡Part of this work was done while at Lawrence Berkeley Laboratory.