Brueckner, K.A.; Serber, R.; Watson, K.M.; The Capture of -Mesons in Deuterium
Phys. Rev. 81 (1951) 575;
Panofsky, Aamodt, and Hadley find that the capture of -mesons in deuterium leads to two neutron emission in 70 percent of the cases, and to two neutrons and a -ray in the other 30 percent. The former process is forbidden for capture of scalar mesons from the K shell. A detailed balancing argument, based on the observed cross section for 2p deuteron +,
permits calculation of the non-radiative capture rate from orbits of higher angular momentum. It is shown that this is too small to account for the observation, and the possibility that the meson is a scalar is thus ruled out. This conclusion could only be avoided by postulating the existence of an interaction between meson and nucleons sufficiently large to alter radically the magnitude of the p-wave functions near the nucleons. For pseudoscalar mesons, non-radiative capture from the K shell is
permitted, and the ratio of radiative to non-radiative transitions can be related to the ratio of meson photoproduction cross section to the cross section for 2p deuteron +. The result is compatible with the type of meson-nucleon coupling which might be expected for pseudoscalar mesons, but uncertainties in the measured quantities are too large to permit a sharper conclusion.
Related references Analyse data from W. K. H. Panofsky, R. L. Aamodt, and J. Hadley, Phys. Rev. 81 (1951) 565;
S. Tamor, Phys. Rev. 78 (1950) 221;
B. Ferreti, Report on the Int. Conf. on Low Temperature and Fundamental Particles, Cambridge (1946) 75;
Confirmation of the odd parity of the .