Search results for "nuclear physics"
showing 10 items of 5307 documents
Normal and intruder configurations in $^{34}$Si populated in the $\beta^-$ decay of $^{34}$Mg and $^{34}$Al
2019
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…
Hyperfine anomaly in gold and magnetic moments of $I^{\pi}$ $= 11/2^{−}$ gold isomers
2020
Physical review / C 101(3), 034308 (2020). doi:10.1103/PhysRevC.101.034308
Testing two-nucleon transfer reaction mechanism with elementary modes of excitation in exotic nuclei
2015
Nuclear Field Theory of structure and reactions is confronted with observations made on neutron halo dripline nuclei, resulting in the prediction of a novel (symbiotic) mode of nuclear excitation, and on the observation of the virtual effect of the halo phenomenon in the apparently non-halo nucleus $^7$Li. This effect is forced to become real by intervening the virtual process with an external (t,p) field which, combined with accurate predictive abilities concerning the absolute differential cross section, reveals an increase of a factor 2 in the cross section due to the presence of halo ground state correlations, and is essential to reproduce the value of the observed $d \sigma(^7$Li(t,p)$…
Precision Mass Measurement of $^{58-63}$Cr: Nuclear Collectivity towards the $N=40$ Island of Inversion
2018
The neutron-rich isotopes $^{58-63}$Cr were produced for the first time at the ISOLDE facility and their masses were measured with the ISOLTRAP spectrometer. The new values are up to 300 times more precise than those in the literature and indicate significantly different nuclear structure from the new mass-surface trend. A gradual onset of deformation is found in this proton and neutron mid-shell region, which is a gateway to the second island of inversion around \emph{N}=40. In addition to comparisons with density-functional theory and large-scale shell-model calculations, we present predictions from the valence-space formulation of the \emph{ab initio} in-medium similarity renormalization…
Study of elastic and inelastic scattering of $^7$Be + $^{12}$C at 35 MeV
2022
6 pags., 5 figs., 2 tabs.
Role of triaxiality in the ground-state shape of neutron-rich Yb, Hf, W, Os and Pt isotopes
2009
The evolution of the ground-state shape of several isotopes of Yb, Hf, W, Os and Pt along the triaxial landscape is analyzed using the self-consistent Hartree-Fock-Bogoliubov approximation. Two well-reputed interactions (Gogny D1S and Skyrme SLy4) have been used in the study in order to assess to which extent the results are independent of the details of the effective interaction. A large number of even-even nuclei, with neutron numbers from N = 110 up to N = 122, have been considered, covering in this way a vast extension of the nuclear landscape where signatures of oblate-prolate shape transitions have already manifested both theoretically and experimentally.
Triton calculations with the new Nijmegen potentials
1993
Triton properties are calculated using new nucleon-nucleon potentials, which were fit to the world nucleon-nucleon data. All potentials are charge dependent and explicitly incorporate the mass difference between the charged and neutral pions. Three of these models have a nearly optimal chi**2 per degree of freedom and can therefore be considered as alternative partial wave analyses, which in quality can almost compete with the Nijmegen partial-wave analysis. The triton binding energy obtained with three local models (Nijm II, Reid93, AV18) can be summarized as 7.62 +_ 0.01 MeV, which is nearly 900 keV lower than experiment. The non-local model Nijm I binds by 7.72 MeV.
Opportunities for Fundamental Physics Research with Radioactive Molecules
2023
Molecules containing short-lived, radioactive nuclei are uniquely positioned to enable a wide range of scientific discoveries in the areas of fundamental symmetries, astrophysics, nuclear structure, and chemistry. Recent advances in the ability to create, cool, and control complex molecules down to the quantum level, along with recent and upcoming advances in radioactive species production at several facilities around the world, create a compelling opportunity to coordinate and combine these efforts to bring precision measurement and control to molecules containing extreme nuclei. In this manuscript, we review the scientific case for studying radioactive molecules, discuss recent atomic, mo…
Nuclear Moments of Germanium Isotopes around $N$ = 40
2020
Collinear laser spectroscopy measurements were performed on $^{69,71,73}$Ge isotopes ($Z = 32$) at ISOLDE-CERN. The hyperfine structure of the $4s^2 4p^2 \, ^3P_1 \rightarrow 4s^2 4p 5s \, ^3P_1^o$ transition of the germanium atom was probed with laser light of 269 nm, produced by combining the frequency-mixing and frequency-doubling techniques. The hyperfine fields for both atomic levels were calculated using state-of-the-art atomic relativistic Fock-space coupled-cluster calculations. A new $^{73}$Ge quadrupole moment was determined from these calculations and previously measured precision hyperfine parameters, yielding $Q_{\rm s}$ = $-$0.198(4) b, in excellent agreement with the literatu…
In-beam gamma-ray and electron spectroscopy of $^{249,251}$Md
2020
The odd-Z Md251 nucleus was studied using combined γ-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the [521]1/2− configuration, another rotational structure has been identified using γ-γ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a [514]7/2− single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of ≃60% was well reproduced by simulating a set of unresolved ex…