Donald Smith

Double beta decay via resonances in the nucleus

Abstract Nuclear double-beta decay is calculated in a model which assumes that the Δ(1236) exists in the nucleus with a probability of approximately 1%. The results obtained with this model are consistent with the observed half-lives.

Lepton number violation in double-beta decay

A model for neutrinoless double-beta decay is presented in which the lepton-violating two-electron current couples to the nucleus in a first-order superweak interaction with coupling strength G′. The interaction is assumed to proceed via an N∗ (1236), with a probability of finding the resonance in the parent or daughter nucleus of roughly 1%. The coupling strength necessary to provide results consistent with all presently available data is found to be G ≅ 10−13 G, where G is the weak coupling strenght.

Application of Moffat's Model to η → 3π and K → 3π Decays

Moffats model for meson–meson scattering, satisfying the Mandelstam representation, crossing symmetry, and Regge behavior, is applied to ηu2002→u20023π and Ku2002→u20023π decays. It is found that agreement with the data is excellent when the model is used with Lovelaces trajectory, but not as good with Moffats trajectory. The model is also applied to the process , and fair agreement is found in the low energy region; however, since the model is unitary only at low energies, no strong conclusions can be reached in this case.

Phenomenological cross sections for the reaction π+d→ppγ

Abstract A phenomenological calculation of the cross sections for the reaction π + d→pp γ is presented, based on the available experimental data for the reaction π + d→pp. The pion lab energy range considered is 150–300 MeV. The geometry is chosen such that the two proton angles are equal, and results are given for various values of that angle.