Nuclear structure of 172Yb

Abstract Detailed angular distributions of the 173 Yb(d,t) 172 Yb and 171 (t,d) 172 Yb reactions have been measured, using 15 MeV beams of deuterons and tritons, and reaction products were analysed with a magnetic spectrograph. The angular distribution for each peak was compared with DWBA predictions to extract spectroscipic strengths for components of different l-values. These strengths were compared with values calculated from the microscopic compositions of states predicted by the Quasiparticle-Phonon Nuclear Model (QPNM). For this purpose, new QPNM calculations using an extended set of base states were performed and are reported. Techniques were developed for performing Coriolis mixing calculations on single-phonon states (i.e., superpositions of two-quasiparticle components). For the first time a good understanding has been obtained for the microscopic structures of the K π = 2 + band at 1608 keV and K π = 3 + band at 1663 keV, which are strongly mixed. Sixteen rotational bands up to 2.6 MeV are interpreted, in addition to many states above 2 MeV which have strong (t,d) populations associated with severely fragmented configurations. The QPNM is very successful in providing a detailed description of the large set of strengths measured. An exception is that for some K π = 0 + bands above the first excited one at 1043 keV, more strength is predicted than observed.