Level structure of odd-oddSb134populated in theβ−decays of

J. Shergur

¹

,

J. Cederkäll

²

Abstract

The level structure of odd-odd 134 Sb has been studied at CERN/ISOLDE following the β − decay of 134 Sn and the β-delayed neutron decay of 135 Sn. Elemental and isobaric separation were accomplished by use of a resonance ionization laser ion source and an on-line mass separator, respectively. Both γ -ray singles and γ -γ coincidence data were taken as a function of time. New levels at 279, 441, 555, 617, and 1385 keV have been identified and given proposed spin and parity assignments of 7 − , 5 − , 6 − , 4 − , and 5 − , respectively, following β-delayed neutron decay of 7/2 − 135 Sn. New 1 − levels have been identified at 1900, 2170, and 2430 keV following the β − decay of 0 + 134 Sn. The resulting level structures are compared to shell-model calculations using the CD Bonn interaction and scaled and unscaled Kuo-Herling interactions developed for the 208 Pb region. Remarkably enough, the unscaled Kuo-Herling interaction provides the best fit for the levels below 1 MeV.

Similarity of nuclear structure in theSn132andPb208Coraggio1, Covello2, Gargano3 et al. 2009Phys. Rev. C573340View full textAdd to dashboardCite

“…As discussed in detail in [20], the measurement of the ground-state spin in 210 Bi as 1 − dates back to some 50 yeas ago [24] and since then the explanation of this peculiar feature has attracted great interest. For 134 Sb, instead, the observation of the 0 − and 1 − states was only a recent experimental achievement [14,25]. Note that our calculations account for the position of the 0 − and 1 − states in both nuclei.…”

“…This has stimulated several shellmodel calculations on nuclei around 132 Sn [12,13,14] with two-body effective interactions originating from the modified version [15] of the Kuo-Herling interaction [16], originally designed for the Pb region. However, these attempts have not been successful, as discussed for instance in [14], where the conclusion was drawn that a consistent Hamiltonian for the three nuclei beyond the N = 82 shell closure, 134 Sb, 135 Sb, and 134 Sn, had yet to be found.In the works of Refs. [4,17,18] we have shown that the properties of these nuclei are well accounted for by a unique shell-model Hamiltonian with SP energies taken from experiment and two-body effective interaction derived from the CD-Bonn N N potential [19].…”

“…In this regard, it is of key importance the fact that, given the correspondence between the SP levels, the matrix elements of the effective interactions in 132 Sn and 208 Pb regions are expected to be proportional to one another. This has stimulated several shellmodel calculations on nuclei around 132 Sn [12,13,14] with two-body effective interactions originating from the modified version [15] of the Kuo-Herling interaction [16], originally designed for the Pb region. However, these attempts have not been successful, as discussed for instance in [14], where the conclusion was drawn that a consistent Hamiltonian for the three nuclei beyond the N = 82 shell closure, 134 Sb, 135 Sb, and 134 Sn, had yet to be found.…”

Investigation of thei13/2neutron orbital in theSn132region: New excited levels inKorgul1, Bączyk2, Urban3 et al. 2015Phys. Rev. C

“…The main contribution to the large uncertainty was the unknown energy of the 7 − isomeric state in 134 Sb, which, at that time, had to be estimated using data from the 208 Pb region (see further in text). Recently, the energy of this isomer has been measured to be 279(1) keV [14] and it is now possible to determine energies of excited states in 134 Sb relative to the ground state without scaling from the 208 Pb region.…”

DECAY OF THE r-PROCESS NUCLIDES 137,138,139Sb AND THE A=130 SOLAR r-PROCESS ABUNDANCE PEAK

“…Guided and motivated by these results, not only has a considerable effort been focused on developing new experimental techniques to identify a large number of new, r-process relevant isotopes (the majority of them in the A ∼ 130 mass region), but also to test in great detail the possible impact of different theoretical models for nuclear masses and gross β-decay properties. The resulting information has been reported in a wide range of publications [1,[4][5][6][7][14][15][16][17][18][19][20][21][22][23][24][25][26][27]29,31,33].…”