Related papers: Degeneracies when only T=1 two-body interactions a…
The mass matrix of three Majorana neutrinos of equal mass is not necessarily proportional to the identity matrix, but expressible in terms of two angles and one phase. We discuss how such a mass matrix may be stable or unstable against…
The behaviour of the i13/2 and h9/2 single-neutron strength was studied with the (4He,3He) reaction on 138Ba, 140Ce, 142Nd and 144Sm targets at a beam energy of 51 MeV. The separation between the single-neutron states i13/2 and h9/2 was…
E2 properties of A=6--10 nuclei, including those of nuclei far from stability, are studied by a $(0+2)\hbar\omega$ shell-model calculation which includes E2 core-polarization effects explicitly. The quadrupole moments and the E2 transition…
Incidental degeneracy and metallic character is probed for weakly coupled plasmas in free and confined environments. The generality of incidental degeneracy in quantum mechanical systems is discussed and demonstrated. It is a fundamental…
Low-lying states in nuclei are investigated using an ensemble of random interactions. Both in the nuclear shell model and in the interacting boson model we find a dominance of $J^P=0^+$ ground states. It is shown that this feature is not…
The isovector M1 transitions between low-lying T=1 and T=0 states in odd-odd N=Z nuclei are analyzed. Simple analytical expressions for M1 transition strengths are derived within a single-j-shell approximation for both j=l+1/2 and j=l-1/2…
Background: The evolution of shell structure around doubly magic exotic nuclei is of great interest in nuclear physics and astrophysics. In the `southwest' region of $^{78}$Ni, the development of deformation might trigger a major shift in…
In this contribution I would like to discuss briefly the recent developments of the nuclear configuration interaction shell model approach. As examples, we apply the model to calculate the structure and decay properties of low-lying states…
Isomeric studies in neutron-rich nuclei present a powerful tool to explore the structure at the nuclear extremes. We recently used the shell model calculations with Renormalized Charge Depen- dent Bonn (RCDB) effective interaction to…
We have performed shell model calculations for neutron deficient even $^{102-108}$Sn and odd $^{103-107}$Sn isotopes in $sdg_{7/2}h_{11/2}$ model space using two different interactions. The first set of interaction is due to Brown {\it et…
We consider two nonperturbative methods originally used to derive shell model effective interactions in nuclei. These methods have been applied to the two nucleon sector to obtain an energy independent effective interaction V_{low k}, which…
I report some progress that occurred since NO-VE08 in the field of non-standard interactions (NSI) of neutrinos. After briefly reviewing theoretical developments, I give a summary of the two works in which I was involved. Firstly, we have…
The ground state energy of infinite symmetric nuclear matter is usually described by strongly interacting nucleons obeying the Pauli exclusion principle. We can imagine a unitary transformation which groups four non identical nucleons (i.e.…
We use the generator-coordinate method with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-beta decay of $^{48}$Ca, $^{76}$Ge, and $^{82}$Se. We…
We consider the impact of neutral-current (NC) non-standard neutrino interactions (NSI) on the determination of the neutrino mass ordering. We show that in presence of NSI there is an exact degeneracy which makes it impossible to determine…
A scheme is proposed which allows to obtain special $q$-oscillator models whose characteristic feature consists in possessing two differing pairs of degenerate energy levels. The method uses the model of two-parameter deformed…
The spin-orbit splittings in the spectra of nuclei with mass numbers 5, 15 and 17 are studied within the framework of shell-model configuration mixing calculations including 2$\hbar \omega$ excitations. The contributions of the two-body…
I discuss the near-degeneracy between models of neutrino-nucleus interactions based on diverse assumptions, and analyze a specific example illustrating how the different reaction mechanisms taken into account, as well as the approximations…
Shell confined atom can serve as a generalized model to explain both \emph{free} and \emph{confined} condition. In this scenario, an atom is trapped inside two concentric spheres of inner $(R_{a})$ and outer $(R_{b})$ radius. The choice of…
We apply the shell-model wave-functions of $^{76}Ge$ to calculate the nuclear matrix elements and the half-life of the $2\nu\beta\beta$ decay in $^{76}Ge$. Our result is comparable to the recent observed $2\nu\beta\beta$-decay half-life of…