0000000000110733
AUTHOR
A. Turturica
Investigation of the Δn = 0 selection rule in Gamow-Teller transitions : The β-decay of 207Hg
Gamow-Teller β decay is forbidden if the number of nodes in the radial wave functions of the initial and final states is different. This Δn = 0 requirement plays a major role in the β decay of heavy neutron-rich nuclei, affecting the nucleosynthesis through the increased half-lives of nuclei on the astrophysical r-process pathway below both Z = 50 (for N > 82) and Z = 82 (for N >126). The level of forbiddenness of the Δn = 1ν1g9/2 → π0g7/2 transition has been investigated from the β− decay of the ground state of 207Hg into the single-proton-hole nucleus 207Tl in an experiment at the ISOLDE Decay Station. From statistical observational limits on possible γ-ray transitions depopulating the π0…
Investigation of the Δn = 0 selection rule in Gamow-Teller transitions: The β-decay of 207Hg
5 pags., 3 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0
Octupole states in Tl207 studied through β decay
The β decay of 207Hg into the single-proton-hole nucleus 207Tl has been studied through γ-ray spectroscopy at the ISOLDE Decay Station (IDS) with the aim of identifying states resulting from coupling of the πs−11/2, πd−13/2, and πh−111/2 shell model orbitals to the collective octupole vibration. Twenty-two states were observed lying between 2.6 and 4.0 MeV, eleven of which were observed for the first time, and 78 new transitions were placed. Two octupole states (s1/2-coupled) are identified and three more states (d3/2-coupled) are tentatively assigned using spin-parity inferences, while further h11/2-coupled states may also have been observed for the first time. Comparisons are made with st…
Evolution of deformation in neutron-rich Ba isotopes up to A=150
12 pags., 11 figs., 3 tabs. -- Open Access funded by Creative Commons Atribution Licence 4.0
Beta-delayed neutron spectroscopy of $^{133}$In
The decay properties of In133 were studied in detail at the ISOLDE Decay Station. The implementation of the Resonance Ionization Laser Ion Source allowed separate measurements of its 9/2+ ground state (In133g) and 1/2− isomer (In133m). With the use of β-delayed neutron and γ spectroscopy, the decay strengths above the neutron separation energy were quantified in this neutron-rich nucleus for the first time. The allowed Gamow-Teller transition 9/2+→7/2+ was located at 5.93 MeV in the In133g decay with a logft=4.7(1). In addition, several neutron-unbound states were populated at lower excitation energies by the first-forbidden decays of In133g,m. We assigned spins and parities to those neutro…
β decay studies of n-rich Cs isotopes with the ISOLDE Decay Station
R. Lica et al. -- 14 pags., 7 figs., tab. -- Open Access funded by Creative Commons Atribution Licence 3.0
Detailed spectroscopy of doubly magic $^{132}$Sn
The structure of the doubly magic $^{132}_{50}$Sn$_{82}$ has been investigated at the ISOLDE facility at CERN, populated both by the $\beta^-$decay of $^{132}$In and $\beta^-$-delayed neutron emission of $^{133}$In. The level scheme of $^{132}$Sn is greatly expanded with the addition of 68 $\gamma$-transitions and 17 levels observed for the first time in the $\beta$ decay. The information on the excited structure is completed by new $\gamma$-transitions and states populated in the $\beta$-n decay of $^{133}$In. Improved delayed neutron emission probabilities are obtained both for $^{132}$In and $^{133}$In. Level lifetimes are measured via the Advanced Time-Delayed $\beta\gamma\gamma$(t) fas…
Normal and intruder configurations in $^{34}$Si populated in the $\beta^-$ decay of $^{34}$Mg and $^{34}$Al
The structure of Si34 was studied through γ spectroscopy separately in the β− decays of Mg34 and Al34 at the ISOLDE facility of CERN. Different configurations in Si34 were populated independently from the two recently identified β-decaying states in Al34 having spin-parity assignments Jπ=4− dominated by the normal configuration π(d5/2)−1⊗ν(f7/2) and Jπ=1+ by the intruder configuration π(d5/2)−1⊗ν(d3/2)−1(f7/2)2. The paper reports on spectroscopic properties of Si34 such as an extended level scheme, spin and parity assignments based on log(ft) values and γ-ray branching ratios, absolute β feeding intensities, and neutron emission probabilities. A total of 11 newly identified levels and 26 tr…
β decay of In133 : γ emission from neutron-unbound states in Sn133
Excited states in Sn-133 were investigated through the beta decay of In-133 at the ISOLDE facility. The ISOLDE Resonance Ionization Laser Ion Source (RILIS) provided isomer-selective ionization for In-133, allowing us to study separately, and in detail, the beta-decay branch of In-133 J(pi)= (9/2(+)) ground state and its J(pi) = (1/2(-)) isomer.Thanks to the large spin difference of the two beta-decaying states of In-133, it is possible to investigate separately the lower and higher spin states in the daughter, Sn-133, and thus to probe independently different single-particle and single-hole levels. We report here new gamma transitions observed in the decay of In-133, including those assign…