Muon capture in 151Eu and 153Eu

Abstract Delayed γ-rays from μ-capture in natural europium were measured with a Ge(Li) detector. From absolute γ-intensities, populations of individual final levels were deduced. In (81±12) % of the μ-capture process, an excited final nucleus was detected. The distribution of excited nuclei is compatible with the neutron multiplicity distribution calculated by Singer; however, the predicted zero neutron emission has not been found. From the analysis of the time distribution of the γ-intensities an isotopic effect for the capture rates was found to be [λ c ( 151 Eu )−λ c ( 153 Eu )]/ λ c = (8.4±2.7) % , which agrees with predictions from Primakoff's μ-capture formula.