The nuclides ${}^{98}\mathrm{Mo}$ and ${}^{100}\mathrm{Mo}$ have been studied in photon-scattering experiments by using bremsstrahlung produced from electron beams with kinetic energies from 3.2 to 3.8 MeV. Six electromagnetic dipole transitions in ${}^{98}\mathrm{Mo}$ and 19 in ${}^{100}\mathrm{Mo}$ were observed for the first time in the energy range from 2 to 4 MeV. A specific feature in the two nuclides is the deexcitation of one state with spin $J=1$ to the $0^{+}$ ground state as well as to the first excited $0^{+}$ state, which cannot be explained in standard models. We present a model that allows us to deduce the mixing coefficients for the two $0^{+}$ shape-isomeric states from the experimental ratio of the transition strengths from the $J=1$ state to the $0^{+}$ ground state and to the $0^{+}$ excited state.

• Received 8 November 2004

DOI:https://doi.org/10.1103/PhysRevLett.95.062501