Cascade process in muon capture : gamma-neutrino angular correlations

A nuclear cascade process resulting from muon capture and subsequent de-excitation by gamma emission is considered. The gamma ray yield is expressed in terms of certain observable correlations involving the three vectors the gamma ray momentum k, the neutrino momentum νsup(→), and the muon polarization P. The process sup(16)O(Osup(+),g.s.)→sup(μ)sup(16)N(1sup(-),392 keV)→sup(γ)sup(16)N(Osup(-),120 keV) has been investigated. The angular correlation coefficients are independent of gsub(P)/gsub(A) but sensitive to gsub(A)/gsub(V) and nuclear structure. The single particle j-j coupling shell-model and the Gillet and Vinh Man wave functions have been used. Simple relations independent of nuclear models and coupling constants of the muon capture interaction are obtained between nuclear recoil asymmetry and the angular correlation coefficients. Measurements of correlation coefficients, therefore, enable one to find α and hence present an alternative to other efforts in the field. (author)