Odd neutron nuclei near A=100: Rotational bands in103Mo and105Mo populated in the? ? decays of103Nb and105Nb

Abstract

The/~-decays of l~ and l~ have been studied at the fission product separators JOSEF and LOHENGRIN. Half-lives of (1.5_0.2)s and (2.95+0.06)s, respectively, have been determined for these decays. From 7 singles and 7-7 coincidence measurements extended level schemes for ~~ and 1~ have been established for the first time. The lowest energy levels of these nuclei are consistent with the interpretation as members of rotational bands built on a 3/2 + [411] Nilsson state. Evidence is presented for the location of the 9/2 + [404] configuration.

Structure of the Triplet of low-lying states in101Mo

“…The number v is an additional quantum number to distinguish, if needed, between different states of the same n d and L Employing this core parametrization and the previous guidelines (2,3,9) for the quasiparticle and boson-fermion interaction parameters, we determine the IBFM parametrization in such a way as to get an overall agreement with the mlMo data. As an example, Fig.…”

“…In the Mo isotopic chain l~ has its place between 99Mo, the low- [1] are well described by the quasiparticle-phonon coupling model [2], and ~~ which has a rotational ground-state band [3]. Therefore, it is interesting to study the structure of ~~ and a variety of experiments on the level scheme have been performed [4,5,6].…”

On the correspondence between rotational bands in the mass regionsA ? 100 andA ? 150

“…Recently, Shizuma et al [3] noticed that the level energies of the v[411 3/2] g.s. bands in 1~176 can be juxtaposed to the rc[411 3/2] bands observed in 151,-,61t, m and 1531~,63x..u by renormalizing the underlying even-even cores of 1~176 to the N=90 Nd, Sm and Gd cores.…”

“…band of lOO~_ has 38o[62 0exp = 0.7-0rig compared to 0~xv = 0.35-0rig for 152~_~ 62~111], the A 5/3 scaling law for the moments of inertia cannot be applied. The above authors [3] therefore propose to use the ratios of the first excited 2 + energies which represent a first-order estimate of the inertial parameter a~E2(/6.…”

“…One could, for example, imagine to derive information on so far non-established odd-neutron Nilsson orbitals from the known corresponding oddproton states in the rare-earth region. For the N = 61 and 63 isotones 99 101 7-38Sr61 [1], 40~,161 [2] and 103,105'/k/f A 42z*ltO61,63 [3] ground-state (g.s.) rotational bands have been established and attributed to the v[411 3/2] Nilsson orbital.…”