Rotational bands in99Sr

Structure of the highly deformed nucleus101Sr63 and evidence for identical K=3/2 bands

“…Based on the similarity between the energies of the 111.6 keV ground-state transition in 101Sr and the first excited U = 7/2-level at 109.4 keV in its isotone 1~ [17], we rather propose I ~ = 5/2-for the ground state of 101Sr. Assuming I '~ = 3/2 + for mlRb, in accordance with the data for lower-mass Rb isotopes [18,26], we have been able to set an upper limit of 3% for the first-forbidden ground-state /3-branch of mlRb decay. The first excited level at lll.6keV in l~ is the I ~ = 7/2 K+ 1 member of the ground-state band.…”

“…The u[41113/2 Nilsson orbital has been assigned to the ground state [18,19], and the deformation was deduced from a lifetime measurement of the first excited state [6]. This result was later confirmed by a Laser spectroscopic study [7].…”

“…Nevertheless, for 99y60 an accurate lifetime of 46 (6) [18]. Thus, deformation parameters and moments of inertia show that the 98Sr 'core' [35] is not much affected by adding either a neutron in the u[41113/2 orbital or a proton in the ~r[42215/2 orbital.…”

“…In 99Rb decay, states up to U = 9/2 + in the 99St daughter nucleus were identified [18,19]. As a matter of fact, there is evidence for these band members in 101Sr, too.…”

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

“…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.…”