Related papers: More on Odd-J Pairing in Nuclei
Analytical expressions of the total number of $J$ levels for three and four fermions in a nuclear $j^n$ shell are provided. The formulas were derived using a combination of sum rules for coefficients of fractional parentage, and "unusual"…
It is pointed out that the ground state of n neutrons and n protons in a single-j shell, interacting through an isoscalar (T=0) pairing force, is not paired, J=0, but rather spin-aligned, J=n. This observation is explained in the context of…
We study the system of semilinear elliptic equations $$-\Delta u_i+ u_i = \sum_{j=1}^\ell \beta_{ij}|u_j|^p|u_i|^{p-2}u_i, \qquad u_i\in H^1(\mathbb{R}^N),\qquad i=1,\ldots,\ell,$$ where $N\geq 4$, $1<p<\frac{N}{N-2}$, and the matrix…
The seniority scheme has been shown to be extremely useful for the classification of nuclear states in semi-magic nuclei. The neutron-proton ($np$) correlation breaks the seniority symmetry in a major way. As a result, the corresponding…
An effective two-body interaction is constructed from a new Reid-like $NN$ potential for a large no-core space consisting of six major shells and is used to generate the shell-model properties for light nuclei from $A$=2 to 6. (For…
In this work nuclear structure properties of $^{86,87,88,89}$Y isotopes have been investigated using large-scale shell-model calculations within the full $f_{5/2}pg_{9/2}$ model space. The calculations have been performed with JUN45 and…
It is here noted that in a calculation with four nucleons with isospin T=1 in a single J shell the states with angular momentum J=(J(max)+1)/2 lie very low and become either isomeric states or ground states.
We explore, within the framework of an algebraic sp(4) shell model, discrete approximations to various derivatives of the energies of the lowest isovector-paired 0^+ states of atomic nuclei in the 40 <A < 100 mass range. The results show…
A new approach to the old problem of the predominance of prolate deformations among well deformed nuclei is proposed within the shell model framework. The parameter space is explored using the ensemble of random rotationally-invariant…
In the single j-shell, the configuration of an even-even Ti isotope consists of 2 protons and n neutrons. The I=0 wave function can be written in terms of D(J,Jv)'s, which are the probability amplitudes for the 2 protons to couple to J and…
The nuclear shell model is one of the successful models in theoretical understanding of nuclear structure. If a convenient effective interaction can be found between nucleons, various observables such as energies of nuclear states are…
The empirical pairing gaps derived from four different odd-even mass staggering formulas are compared. By performing single-$j$ shell and multi-shell seniority model calculations as well as by using the standard HFB approach with Skyrme…
The pairing correlation energy for two-nucleon configurations with the spin-parity and isospin of $J^\pi=0^+$, $T$=1 and $J^\pi=1^+$, $T$=0 are calculated with $T$=1 and $T$=0 pairing interactions, respectively. To this end, we consider the…
We report $J^\pi = 0^+$ ground-state energies and point-proton radii of $^4$He, $^8$Be, $^{12}$C, $^{16}$O and $^{20}$Ne nuclei calculated by the $ab$ $initio$ no-core Monte Carlo shell model with the JISP16 and Daejeon16 nonlocal $NN$…
The level structure of the very neutron rich and unbound $^9$He nucleus has been the subject of significant experimental and theoretical study. Many recent works have claimed that the two lowest energy $^9$He states exist with spins…
The influence of quadrupole and hexadecapole residual interactions on rotational bands is investigated in a single-j shell model. An exact shell-model diagonalization of quadrupole-plus-hexadecapole interaction can sometimes produce a…
The attractive interaction between $J/\psi$ and $\psi(3770)$ has to be strong enough to form the molecular resonant structure, i.e., $X(6900)$. We argue that since $\psi(3770)$ decays predominantly into a $D\bar D$ pair, the interactions…
The role of superfluidity in the incompressibility and in the symmetry energy is studied in nuclear matter and finite nuclei. Several pairing interactions are used: surface, mixed and isovector dependent. Pairing has a small effect on the…
It is shown that in N \simeq Z nuclei the effects of isovector pairing and the symmetry energy are intimately related. In particular, in the odd-odd N = Z nuclei these two effect are essentially equal in magnitude, causing near degeneracy…
The extended pairing plus $QQ$ interaction with the $J$-independent isoscalar proton-neutron force as an average monopole field, which has succeeded in describing collective yrast states of $N \approx Z$ even-$A$ nuclei, is improved. The…