Proton-neutron multiplets in96Y

Abstract

The structure of the nucleus 96 39Y57 is discussed in the framework of the parabolic rule for the splitting of members of proton-neutron coupled configurations and of the interacting boson-fermion-fermion model (IBFFM). A good description of the available experimental data including the existence of the /~-decaying 8 + isomer with a half-life of 10 s has been obtained which demonstrates the influence of the subshell closures in the neighbourhood of 96Zr56.

Structure of theN=59 nucleus97Sr: coexistence of spherical and deformed states

“…It is tempting to interpret the first excited state with U= 3/2 + as the d3/2 single neutron state. However, our BCS as well as recent IBFFM calculations of the oddodd 96Y57 and 98y59 nuclei [24][25][26], indicate that this orbital must lie higher. The nature of the 3/2 + level is therefore more complex (see below), probably containing sizeable admixtures of the g7/2 configuration in addition to the d3/2 single neutron orbital.…”

“…In this framework the structure of nuclei in the A ~,, 100 region was recently investigated [9,[24][25][26][34][35][36]. Thus, IBFM should be an appropriate approach for a theoretical description of the spherical states in 97Sr.…”

Structure of the Triplet of low-lying states in101Mo

“…Since the y-ray intensity of the 43.5 keV transition is only 2.37(16)/100 n, the total conversion coefficient of this transition must be 14.1 (13). The depopulation through a possible 57.0 keV transition can be neglected: from the upper limit of 0.02/ 100 n for the y-ray intensity of the 57.0 keV E2 groundstate transition and the theoretical total conversion coefficient e, (E2) = 9.11 [ 17] the total 57.0 keV transition intensity results as _<0.2/100 n. With e,(M1)=2.77, 7t (E2) = 23.9, c~ t (El) = 1.38 and et (M2) = 62.4 [17] the E2 or M2 component in the 43.5 keV transition is deduced as 53(10)% and 21(3)%, respectively, in good agreement with the results from the study at JOSEF.…”

“…We have previously performed calculations for odd-A and odd-odd nuclei in this region [13,40,41]. The parameters of the positive parity neutron configurations are collected in Table 3.…”

“…Recently, calculations for odd-even nuclei [11,12] and for odd-odd nuclei [12,13] in the region around A = 100 have been performed successfully in the framework of the interacting boson-fermion model (IBFM) and the interacting boson-fermion-fermion model (IBFFM), respectively. Therefore, the IBF model in the equivalent representation of the particle-truncated quadrupole-phonon coupling model (PTQM) has now been applied to 1~ In particular, the studies aimed at answering the question whether the ground-state is of the (d5/2)~/2; j-2 type, similar to the 167 keV 3/2 + state in the isotone 97Sr which according to IBFM calculations contains a strong component of the configuration 3 (g7/~)3/2.…”