Recent results of decay spectroscopy at RIBF

Hiroshi Watanabe, C. Simenel, M. Evers, T. Kibédi, D. Huy Luong, M. Reed, M. Srncik, A. Wallner
2013 EPJ Web of Conferences  
The neutron-rich nuclei 109 Nb and 110 Mo have been investigated by means of β-γ and isomer spectroscopy following in-flight fission of a 238 U beam at 345 MeV/nucleon at the RIBF facility. A T 1/2 = 150(30) ns isomer at 313 keV has been identified in 109 Nb. The low-lying levels in 109 Nb have been also populated following the β-decay of 109 Zr. The observed hindrances of the electromagnetic transitions deexciting the isomeric state are discussed in terms of possible shape coexistence. For 110
more » ... Mo, spectroscopic information on the low-lying levels of the quasi-γ band built on the 2 + 2 state at 494 keV has been obtained for the first time. The experimental finding of the 2 + 2 state being lower than the 4 + 1 level suggests that axially-asymmetric γ softness is substantially enhanced in this nucleus. The experimental results are compared with model calculations based on the general Bohr Hamiltonian method. A new project of decay spectroscopy at RIBF, named EURICA, is also introduced.
doi:10.1051/epjconf/20136301001 fatcat:mjbav3jkkregjdwnm4s4yoh3rm