Proton-hole excitations in 201, 203Au from 202, 204Hg(t, α) reactions

The 202, 204Hg(t, α) reactions have been performed to investigate the proton-hole states of 201, 203Au, for which no knowledge of the level structures was previously available. The results yield ground-state masses and locate a number of excited states below 2.5 MeV in each nuclide. Spins and parities of these levels can be assigned from angular distributions of the analyzing powers and differential cross sections, with the latter also being used to determine spectroscopic strengths. The results indicate a rather rapid fragmentation of single-proton strength as one goes away from the Z=82 closed shell, indicating a more collective structure.