Nuclear model effects in neutrino-nucleus quasielastic scattering are studied within the distorted wave impulse approximation, using a relativistic shell model to describe the nucleus, and comparing it with the relativistic Fermi gas. Both charged-current and neutral-current processes are considered and, for the neutral-current case, the uncertainties that nuclear effects may introduce in measu...

We investigate the shell structure of spherical nuclear bubbles in simple phenomenological shell model potentials. The bunching is produced by the energy gaps between single-particle states with a different number of radial nodes. The shell correction energies for doubly magic bubbles may be as large as –40 MeV and probably imply a very long lifetime against spontaneous fission. β-stability occ...

The Shell model Monte Carlo (SMMC) method [1] was developed as an alternative to direct diagonalization in order to study low-energy nuclear properties. It was successfully applied to nuclear problems where large model spaces made diagonalization impractical. One calculates the thermal canonical expectation values of observables of few-body operators by representing the imaginary-time many-body...

Experimental data on light nuclei close to dripline suggests that as the nucleon number asymmetry increases, the shell structure from stability line is not preserved. In contrast with spherical shell model, Elliott’s SU(3) model, uses a deformed multi-nucleon basis to describe nuclear states. The SU(3) symmetry is a strong feature of 1p shell nuclei, where symmetry breaking spin-orbit force is ...

An interesting aspect of nuclear dynamics is the co–existence, in atomic nuclei, of regular and chaotic states [1]. This is a vast subject and, for reasons of space, in this paper we limit ourselves to a few examples only. In order to highlight the difference between the regular and chaotic states, it is perhaps useful to remember that the low energy states (0 ∼ 4 MeV above the ground state), t...

The excitation function for the fusion-evaporation reaction Ni + Mo has been measured down to a cross-section of ∼ 5 nb. Extensive coupled-channels calculations have been performed, which cannot reproduce the steep fall-off of the excitation function at extreme sub-barrier energies. Thus, this system exhibits a hindrance for fusion, a phenomenon that has been discovered only recently. In the S-...

The pairing gap for 53Ca obtained from new experimental data on the masses of (52-54)Ca has the smallest value yet observed. This is explained in the framework of the nuclear shell model with schematic and realistic Hamiltonians as being due to shell gaps around the low-j orbital 1p(1/2). Minima in the pairing gaps for all nuclei are shown and discussed.

In the polyspheron theory of nuclear structure,' approximate wave functions for the normal state and some excited states of nuclei are constructed of localized is orbitals occupied by one to four nucleons; a nucleus is described in terms of deuterons, tritons, trelions,2 and helions,3 as well as neutrons and protons not included in these clusters (spherons). In the following paragraphs I point ...

It has been shown that the nuclear shell model depicts very well the structure of nuclei with mass A~208 (see [1] for example). This model describes the motion of nucleons outside an inert core (closed shells) that contains a magic number of protons and neutrons, more preferably both. In the region of interest here the doubly magic nucleus 208 Pb (Z=82, N=126) is initially taken as the core. Th...

We employ the density matrix renormalization group (DMRG) and the wave function factorization method for the numerical solution of large scale nuclear structure problems. The DMRG exhibits an improved convergence for problems with realistic interactions due to the implementation of the finite algorithm. The wave function factorization of fpg-shell nuclei yields rapidly converging approximations...