On the nuclear symmetry energy and the neutron skin in neutron-rich nuclei

The symmetry energy for nuclear matter and its relation to the neutron skin in finite nuclei is discussed. The symmetry energy as a function of density obtained in a self-consistent Green function approach is presented and compared to the results of other recent theoretical approaches. A partial explanation of the linear relation between the symmetry energy and the neutron skin is proposed. The potential of several experimental methods to extract the neutron skin is examined.Comment: to appear in Phys. Rev.

E1 transitions between spin-dipole and Gamow-Teller giant resonances

The branching ratios for E1 transitions between the spin-dipole (SD) and Gamow-Teller (GT) giant resonances in $^{90}$Nb and $^{208}$Pb are evaluated. Assuming the main GT-state has the wave function close to that for the "ideal" GT-state, we reduced the problem to calculate the SD and GT strength functions. These strength functions are evaluated within an extended continuum-RPA approach.Comment: 8 pages, submitted to Phys. Rev.

Nuclear Structure Aspects of the Neutrinoless Double Beta Decay

In this article, we analyze some nuclear structure aspects of the neutrinoless double beta decay nuclear matrix elements (NME), in the framework of the Interacting Shell Model. We give results for the decays of 48Ca, 76Ge, 82Se, 124Sn, 128Te, 130Te, and 136Xe, using improved effective interactions and valence spaces. We examine the dependence of the NME's on the effective interaction and the valence space, and analyze the effects of the short range correlations and the finite size of the nucleon. Finally we study the influence of the deformation on the values of the NME's.Comment: To appear in EJP-

Hamiltonian formalism of the Landau-Lifschitz equation for a spin chain with full anisotropy

The Hamiltonian formalism of the Landau-Lifschitz equation for a spin chain with full anisotropy is formulated completely, which constructs a stable base for further investigations.Comment: 11page

On stochastic switching of bistable resonant-tunneling structures via nucleation

We estimate the critical size of the initial nucleus of the low current state in a bistable resonant tunneling structure which is needed for this nucleus to develop into a lateral switching front. Using the results obtained for deterministic switching fronts, we argue that for realistic structural parameters the critical nucleus has macroscopic dimensions and therefore is too large to be created by stochastic electron noise.Comment: the extended version of the Comment on "Lifetime of metastable states in resonant-tunneling structures" to appear in Phys. Rev.