Muonic 197Au: A test of the weak-coupling model☆

Abstract We report the measurement of the energies of various muonic atomic transitions above 500 keV in 197 Au. We have used the weak-coupling model in order to analyze the hyperfine structure of 197 Au. Using transitions to and from the 1s, 2s 2p and 3p levels as well as the fine structure of the 2p states and hyperfine splittings of the 2p, 3p and 3d states we have fitted our data to two deformed Fermi distributions: one with a constant skin thickness, the other with a skin thickness which varies. Both yield equally good fits. We have determined the quadrupole moment of 197 Au to be 0.547±0.016 b. The model dependence of our results is discussed. The weak coupling parameters of de-Shalit Ω p , Ω 22 , Ω 20 and A 2 have been determined and are in fair agreement with Coulomb excitation results. There is also good agreement between our results and those of electron scattering.