Radiative Muon Capture in Calcium

The branching ratio relative to ordinary muon capture and the photon asymmetry relative to the muon-spin direction were measured for radiative muon capture in /sup 40/Ca. For approx. 1200 photon events, the partial branching ratio is R/sub k>/sub 57/MeV/ = (21.1 +- 1.4) x 10/sup -6/, and the asymmetry for k > 63.5 MeV is +0.90 +- 0.50. A fit of the photon spectrum to the theory of Rood, Yano, and Yano gives the value g/sub p//sup ..mu../ = (6.5 +- 1.6) g/sub A/ for the pseudoscalar-coupling constants. These results are in disagreement with earlier experiments.