Related papers: Emergence of the N=16 shell gap in 21O
Experimental energy spectrum and B(E2) values in 68Ni and 90Zr indicate a double-magic character in these neutron-rich nuclei with N or Z=40. The data nevertheless do not show any pronounced irregularity in two-nucleon separation energy. To…
Inspired by the recently-reported strong electric-dipole (E1) transition between the weakly-bound first and second excited states, 3/2- at 765 keV and 1/2+ at 885 keV, in the nucleus 27Ne, the E1 transition is estimated in a model by…
We study ground- and excited-state properties of all sd-shell nuclei with neutron and proton numbers 8 <= N,Z <= 20, based on a set of low-resolution two- and three-nucleon interactions that predict realistic saturation properties of…
The reaction $^{11}B+p$ has been used to populate the $(J^{\pi},T)=(2^+,1)$ state at an excitation energy of 16.11 MeV in $^{12}$C, and the breakup of the state into three $\alpha$ particles has been studied in complete kinematics. A…
The onset of intruder ground states in Na isotopes is investigated by comparing experimental data and shell-model calculations. This onset is one of the consequences of the disappearance of the N=20 magic structure, and the Na isotopes are…
The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a 10C beam with an energy of 9.0 MeV/u. An additional measurement was done…
The neutron rich exotic unbound 7He nucleus has been the subject of many experimental investigations. While the ground-state 3/2- resonance is well established, there is a controversy concerning the excited 1/2- resonance reported in some…
The evolution of the N=28 neutron shell closure is studied in the N=28 isotones from neutron drip line's $^{40}$Mg to N=Z doubly magic $^{56}$Ni. It is found that the N=28 closure vanishes at Z=12 in favor of a deformed ground state. For…
The very neutron-rich oxygen isotopes 25O and 26O are investigated experimentally and theoret- ically. In this first R3B-LAND experiment, the unbound states are populated at GSI via proton- knockout reactions from 26F and 27F at…
We investigate the ground state properties of $^{22}$C by using a deformed relativistic Hartree-Bogoliubov model in continuum and explore the interplays among the formation of a halo, deformation effects, the inversion of $sd$ states, the…
An experimental study of the 16O(e,e'K^+)16N_Lambda reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K^+)Lambda,Sigma_0 exclusive…
Neutron-unbound resonant states of 11Be were populated in neutron knock-out reactions from 12Be and identified by 10Be-n coincidence measurements. A resonance in the decay-energy spectrum at 80(2) keV was attributed to a highly excited…
The structure of exotic nucleus 10N was studied using 9C+p resonance scattering. Two L=0 resonances were found to be the lowest states in 10N. The ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2) MeV depending…
The existence of magic numbers of protons and neutrons in nuclei is essential for understanding nuclear structure and fundamental nuclear forces. Over decades, researchers have conducted theoretical and experimental studies on the new magic…
Excited 0+ states are studied in the framework of the projected shell model, aiming at understanding the nature of these states in deformed nuclei in general, and the recently observed 13 excited 0+ states in 158Gd in particular. The model,…
We study the spectra of neutron-rich oxygen isotopes based on chiral two- and three-nucleon interactions. First, we benchmark our many-body approach by comparing ground-state energies to coupled-cluster results for the same two-nucleon…
The available experimental data on shell evolution indicate that the strength of the spin-orbit (SO) single-particle potential may be enhanced in neutron-rich nuclei. We observe that such a simple scheme destroys the Harmonic Oscillator…
The $^{18}$Ne($\alpha$,$p$)$^{21}$Na reaction provides a pathway for breakout from the hot CNO cycles to the $rp$-process in type I x-ray bursts. To better determine this astrophysical reaction rate, the resonance parameters of the compound…
In this work we report the opening of an energy gap at the filling factor $\nu=3+1/3$, firmly establishing the ground state as a fractional quantum Hall state. This and other odd-denominator states unexpectedly break particle-hole symmetry.…
Evidence for the ground state of the neutron-unbound nucleus 26O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u 27F beam. Neutrons were measured in coincidence with 24O fragments. 26O was determined…