Comprehensive studies of low-spin collective excitations in 94Mo -: art. no. 024307

Excited low-spin states in Mo-94 have been studied extensively with a combination of gamma-ray spectroscopic techniques. We have performed photon scattering experiments, gammagamma coincidence measurements following the beta(+) decay of Tc-94(m), in-beam gammagamma coincidence studies with the reaction Zr-91(alpha,n)Mo-94, and Mo-94(n,n(')gamma) measurements. These experiments yielded detailed information about the low-spin level scheme of Mo-94. From measured lifetimes, branching ratios, and multipole mixing ratios, many absolute transition strengths were determined. These data permitted the interpretation of several low-spin states in terms of collective excitations, that are not fully symmetric with respect to the proton-neutron degree of freedom, the so-called mixed-symmetry (MS) states: The one-phonon 2(+) MS state and three members of an expected multiplet of two-phonon MS states were identified from absolute M1 and E2 transition strengths. The data also enable us to identify several proton-neutron-symmetric multiphonon states.