0000000000122008
AUTHOR
Slobodan Brant
showing 12 related works from this author
Structure of the neutron-rich nucleus 37 94 rb57
1989
A level scheme has been established for 37 94 Rb57 based on studies at the fission-product separator JOSEF ofγγ coincidences following theβ- decay of94Kr. For the 190.7 keV level a half-life of 2.5(8) ns has been determined through the centroid-shift method. The majorβ-decay branch of94Kr proceeds with log ft=3.7 into the 988.4 keV state in94Rb. This transition must be of the 0+→1+ GT type involving the transitionνg7/2→πg9/2. IBFFM calculations have been performed for94Rb, starting from the parametrization used in the previous IBM investigations for the isotope93Rb and the isotone96Y. A theoretical interpretation of the low-lying levels including propositions for the spins is given in a com…
Level structure of ^100Nb
2000
Levels in the odd-odd nucleus ${}^{100}\mathrm{Nb}$ situated at the edge of a region of especially fast shape transitions have been calculated in the framework of the interacting boson fermion fermion model. Levels observed in decay studies can be interpreted in a spherical basis. Low-lying ${I}^{\ensuremath{\pi}}{=8}^{+}$ and ${10}^{\ensuremath{-}}$ states are predicted. Their relationship with the unplaced levels populated with a $12 \ensuremath{\mu}\mathrm{s}$ delay after fission is discussed.
IBFFM predictions for low-lying spherical states in the shape-coexisting odd-odd nucleus98Y
1989
Extrapolating the Interacting Boson-Model treatment from lighter neighbours to98Y we predict the properties of low-lying states of spherical nature in IBFFM. This odd-odd nucleus which presents one of the rare cases of coexisting spherical and deformed shapes is of fundamental importance for understanding nuclear phase transitions.
Collective and broken pair states of65,67Ga
1999
Excited states of 65Ga and 67Ga nuclei were populated through the 12C(58Ni,αp) and 12C(58Ni,3p) reactions, respectively, and investigated by in-beam γ-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and γ rays. The level schemes of 65,67Ga were constructed on the basis of γγ-coincidence relations up to 8.6 and 10 MeV excitation energy, and Iπ=27/2 and 33/2+ spin and parity, respectively. The structure of 65,67Ga nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in…
Structure of theN=59 nucleus97Sr: coexistence of spherical and deformed states
1990
A band with a rotational pattern based on a state at 585.1 keV has been identified in theN=59 neutron-rich nucleus97Sr. Its properties lead to the [422] 3/2 Nilsson-orbital assignment for the band head. There is evidence for a second band with the head at 644.7 keV and the configuration [541] 3/2. Since the ground state and the lowest excited levels are spherical, shape coexistence is established for97Sr. A deformed nature of several levels at 500–600 keV results also from QRPA-model calculations. The structure of the low-lying spherical levels has been studied in the frame of the IBF model. The results of the present investigations lead to a better understanding of theN=59 isotones which c…
Nuclear structure of97Y in the interacting boson-fermion model
1988
Unique-parity states of97Y are studied in the framework of the interacting boson-fermion model (IBFM). Spin assignments for the levels of the unique-parity yrast band are proposed on the basis of nuclear systematics and the IBFM band pattern associated with coupling of a particle-type quasiparticle (g9/2) to the SU(5) core3896Sr58. The good fit of the experimental data with the IBFM calculations confirms the single particle character of this immediate neighbour of the doubly sub-magic nucleus96Zr.
Structure of 68As studied via the 12C(58Ni,pn) reaction
1998
Excited states of As-68 nucleus were populated through the C-12(Ni-58,pn) reaction and investigated by in-beam gamma-spectroscopic methods. The NORDBALL detector array equipped with charged particle and neutron detectors was used to detect the evaporated particles and gamma-rays. The level scheme of As-68 was constructed on the basis of gamma gamma-coincidence relations up to 6 MeV excitation energy and J(pi) = (15(+)). The structure of the nucleus is discussed in the framework of the interacting boson-fermion-fermion model. The states below 2.3 MeV are described as members of proton-neutron-phonon multiplets. (C) 1998 Elsevier Science B.V.
Level structure of 99Nb
1998
The β decay of 97Sr to 97Y has been investigated using ion-guide on-line mass separation and a 10 Ge-detector array to record γ−γ coincidences to a detection limit well below that of former studies. Similarities are found in the β-decay patterns of 99Zr and of its isotone 97Sr and also in the γ-ray decay rates and branchings of the corresponding levels in their respective daughters 99Nb and 97Y. This indicates a persisting influence of the d5/2 neutron shell closure for 99Nb. The level structure of 99Nb and the β-feeding pattern are discussed in the frame of the interacting boson-fermion plus broken pair model and the microscopic quasiparticle phonon model.
Nature of93Rb levels studied in IBFM
1989
The structure of the low-lying states with negative parity of3793Rb56 has been studied in the framework of the Interacting Boson-Fermion Model (IBFM) using the even-even neighbour3894Sr56 as a core. A good description of the properties of the levels has been obtained. A sensitive test of the quality of the theoretical studies is the decay pattern of the second excited state at 267 keV with a half-life of 2.0(2) ns. The calculations givet1/2=2.26 ns and they predict the existence of a 13 keV transition into the first excited state, the existence of which has been confirmed afterwards by experiments.
Nuclear structure of97Yin the interacting boson fermion plus broken pair model and the nature of the 3.523 MeV high-spin isomer
1998
Nuclear structure of 97Y is described in the interacting boson fermion plus broken pair model, including quasiproton and quasiproton-two-quasineutron configurations in the basis states. In particular, the yrast bands and the decay of the 27/2- high-spin isomer are accounted for in this approach.
Lifetime measurements in mirror nuclei31S and31P: A test for isospin mixing
2011
Using the 20Ne + 12C fusion-evaporation reaction at E20Ne = 33 MeV and the multidetector array GASP in conjuction with the EUCLIDES charged particle detector, angular correlations of coincident pairs of γ transitions and lifetimes in mirror nuclei 31S and 31P have been measured at the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. A comparison of the determined B(E1) strengths of the analog mirror 7/2− → 5/2+ transitions indicates the presence of a violation of isospin symmetry.
TheK=3/2 1 + side-band in99Y and its description by the IBFM/PTQM model
1986
The K=3/21T rotational band has been identified in99Y with a band-head energy of 536 keV. This result is in contradiction with previously reported data, but is in agreement with predictions of the IBFM/PTQM model.