High-spin structures in Xe132 and Xe133 and evidence for isomers along the N

Abstract

The transitional nuclei 132 Xe and 133 Xe are investigated after multinucleon-transfer (MNT) and fusionevaporation reactions. Both nuclei are populated (i) in 136 Xe + 208 Pb MNT reactions employing the highresolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the 136 Xe + 198 Pt MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a 130 Te(α,xn) 134−xn Xe fusion-evaporation reaction employing the HORUS γ -ray array at the University of Cologne. The high-spin level schemes are considerably extended above the J π = (7 − ) and (10 + ) isomers in 132 Xe and above the 11/2 − isomer in PHYSICAL REVIEW C 96, 024321 (2017) isotones. Shell-model calculations employing the SN100PN and PQM130 effective interactions reproduce the experimental findings and provide guidance to the interpretation of the observed high-spin features.

High-spin structure in the transitional nucleus Xe131 : Competitive neutron and proton alignment in the vicinity of the N=82 shell closure

“…13(b). Both calculations predict a first alignment at the J π = 6 [39] is in good agreement with the results by the untruncated SN100PN calculation. In 132 Xe the alignment is clearly caused by protons in the πh 11/2 orbital.…”

“…5 MeV is consistent with other populated reaction channels in both AGATA@LNL experiments [39,69,70]. Unassigned γ -ray transitions observed with AGATA and listed in Table I do not yield meaningful γ -γ coincidences in the HORUS experiment.…”

“…Consequently, it is likely that the J π = 8 + 1 state is located very close in energy to the J π = 10 + 1 isomer, resulting in a pronounced backbending. This assumption is supported by shell-model calculations [39]. To shade light on the nuclear structure of 132 Xe around the J π = 10 + 1 state, the high-spin structures of the odd-mass neighboring nuclei can be used to investigate the inert core 132 Xe by means of a semiclassical description within the particle-plus-rotor picture.…”

“…To shade light on the nuclear structure of 132 Xe around the J π = 10 + 1 state, the high-spin structures of the odd-mass neighboring nuclei can be used to investigate the inert core 132 Xe by means of a semiclassical description within the particle-plus-rotor picture. In 133 Xe the single-particle character dominates over the collective character [39]. For the lower odd-mass neighbors of 131 Xe, 125 Xe, and 127 Xe, both low-spin structures from 3 He-and α-induced reactions [40,41] and elaborate high-spin information from heavy-ion reactions are available.…”

Emerging collectivity from the nuclear structure of Xe132 : Inelastic neutron scattering studies and shell-model calculations

“…A number of shellmodel calculations have been performed for the Xe isotopes near N = 82 [2,[17][18][19][20][21][22]. Recent work includes an extensive study of nuclei around mass 130 by Teruya et al [19], calculations on 132 Xe and 134 Xe to high spin by Vogt et al [21,22], and calculations for the low-seniority states of 136 Xe by Van Isacker [2]. These calculations included all of the orbitals in the 50 ≤ N, Z ≤ 82 major shell for both protons and neutrons, namely 0g 7/2 , 1d 5/2 , 1d 3/2 , 2s 1/2 , and 0h 11/2 , but employed different interactions.…”