Related papers: Pairing Interaction in N=Z Nuclei with Half-filled…
We discuss several pairing-related phenomena in nuclear systems, ranging from superfluidity in neutron stars to the gradual breaking of pairs in finite nuclei. We focus on the links between many-body pairing as it evolves from the…
Lattice Hamiltonians with on-site interaction $W$ have W=0 solutions, that is, many-body {\em singlet} eigenstates without double occupation. In particular, W=0 pairs give a clue to understand the pairing force in repulsive Hubbard models.…
The spectrum of an exactly solvable non-relativistic system of a charged particle interacting with a quantized electromagnetic mode is studied with various polarizations. Quasiparticle dispersion relations can be derived from the…
The spin magnetic dipole transitions and the neutron-proton spin-spin correlations in $sd-$shell even-even nuclei with $N=Z$ are investigated using shell model wave functions. The isoscalar spin-triplet pairing correlation provides a…
The linear term proportional to $|N-Z|$ in the nuclear symmetry energy (Wigner energy)is obtained in a model that uses isovector pairing on single particle levels from a deformed potential combined with a $\vec T^2$ interaction. The pairing…
The description of structural and dynamical properties of nuclei starting from the fundamental interaction between nucleons has been a long-standing goal in nuclear physics. The ab initio No-Core Shell Model combined with the…
We count the number of pairs in the single $j-$shell model of $^{44}$Ti for various interactions. For a state of total angular momentum $I$, the wave function can be written as $\Psi=\sum_{J_P J_N} D(J_P J_N) [(j^2)_{J_P}(j^2)_{J_N}]_I$,…
We count the number of pairs in the single j-shell model of {44}Ti for various interactions. For a state of total angular momentum I, the wave function can be written in terms of the probability amplitude D(Jp Jn) that the protons couple to…
Analysis of various mass relations connected with neutron-proton correlations in atomic nuclei is carried out. On the example of $N = Z$ chain it is shown that for self-adjoint nuclei various formulas proposed in literature for $ np $…
Direct analytical and numerical calculation show that two-electron atomic configuration can be unstable with respect to a static or dynamic shift of the electron shells. This enables to develop a so called non-rigid shell model for a…
The pseudo-SU(3) model is used to describe the low-energy spectra as well as $E2$ and $M1$ transition strengths in $^{158}$Gd. The Hamiltonian includes spherical single-particle energies, the quadrupole-quadrupole and proton and neutron…
Neutron rich Zr nuclei with number of neutrons between $N$= 50 and 82 are investigated in the relativistic mean field approach in co-ordinate space. The resonant levels in the positive energy continuum have been explicitly included in the…
We perform analysis of realistic nucleon-nucleon interactions, as well as of empirically-corrected interactions, fitted to reproduce in detail the spectroscopic data in p and sd shells. We focus on the multipole part of the interactions,…
The Interacting Boson plus broken-pairs Model has been used to describe high-spin bands in spherical and transitional nuclei. In the spherical nucleus $^{104}$Cd the model reproduces the structure of high-spin bands built on a vibrational…
We present expressions for the matrix elements of the spin--spin operator $\vec S_{\rm n}\cdot\vec S_{\rm p}$ in a variety of coupling schemes. These results are then applied to calculate the expectation value $\langle\vec S_{\rm…
We study the effect of effective mass on pairing correlations in the ground states of superfluid nuclei $^{124}$Sn and $^{136}$Sn. Various parameter sets of Skyrme interactions and relativistic Lagrangians are adopted to study pairing…
Finite nuclei such as those found in the chain of even tin isotopes from ^{102}Sn to ^{130}Sn, exhibit a near constancy of the 2^+_1-0^+_1 excitation energy, a constancy which can be related to strong pairing correlations and the near…
[Background] Nuclear pairing is a well-established many-body correlation, particularly among like particles in a spin-singlet state. However, the strength of spin-triplet proton-neutron (pn) pairing in nuclei has remained a long-standing…
The neutron-neutron and proton-proton pairing correlations have long been recognised to be the dominant many-body correlation beyond the nuclear mean field since the introduction of pairing mechanism by Bohr, Mottelson and Pines nearly 60…
We study in detail the dependence of the 1S0 superfluid pairing gap on nuclear interactions and on charge-independence breaking at the BCS level. Starting from chiral effective-field theory and conventional nucleon-nucleon (NN)…