S. A. Fayans

Nuclear isotope shifts within the local energy-density functional approach

Abstract The foundation of the local energy-density functional method to describe the nuclear ground-state properties is given. The method is used to investigate differential observables such as the odd–even mass differences and odd–even effects in charge radii. For a few isotope chains of spherical nuclei, the calculations are performed with an exact treatment of the Gorkov equations in the coordinate-space representation. A zero-range cutoff density-dependent pairing interaction with a density-gradient term is used. The evolution of charge radii and nucleon separation energies is reproduced reasonably well including kinks at magic neutron numbers and sizes of staggering. It is shown that the density-dependent pairing may also induce sizeable staggering and kinks in the evolution of the mean energies of multipole excitations. The results are compared with the conventional mean field Skyrme–HFB and relativistic Hartree–BCS calculations. With the formulated approach, an extrapolation from the pairing properties of finite nuclei to pairing in infinite matter is considered, and the dilute limit near the critical point, at which the regime changes from weak to strong pairing, is discussed.

Towards a better parametrization of the nuclear pairing force: density dependence with gradient term

Abstract A new form of effective density dependent pairing interaction with gradient term leading to the concentration of the pairing gap field in the outer part of the nuclear surface is suggested. Within the framework of the density functional method supplemented with such an interaction the observed trends in isotope shifts of charge radii are nicely reproduced. This is demonstrated by example of the Pb chain.

Isotope shifts within the energy-density functional approach with density dependent pairing☆

Abstract We demonstrate that incorporating a density-dependent pairing-correlation term in the energy-density functional allows one to self-consistently reproduce the observed trends both in nuclear binding energies and in charge radii including odd-even staggering effects and kinks at magic neutron numbers. Results for calcium, tin and lead isotopes are presented and discussed.

Energy-density functional approach for non-spherical nuclei

Abstract The extension of the self-consistent energy-density functional method to non-spherical nuclei is briefly described. A comparison of the spherical and the non-spherical approach in lead nuclei is given and first results for the chain of strongly deformed dysprosium isotopes are presented.

Quasielastic scattering of light exotic nuclei. A semi-microscopic folding analysis

Abstract Angular distributions and total reaction cross sections for the quasielastic scattering of (i) 8 B and 7 Be on 12 C at E lab = 40 MeV/nucleon, (ii) 11 Li on 28 Si at E lab = 29 MeV/nucleon, and (iii) 11 C and 11 Li on 12 C at lab = 60 MeV/nucleon are studied with coupled-channels calculations using double-folding optical potential based on the M3Y effective interaction and densities obtained within the energy-density functional approach with a fixed parameter set for all colliding nuclei. An imaginary part of the optical potential is constructed from folding the real one with two free parameters for volume and surface absorption. It is shown that a fairly good description of the experimental data can be achieved within a rather restricted range of these free parameters without renormalization of the real part of the optical potential. The analysis confirms the long neutron tail (halo) in 11 Li and supports a rather thick proton skin in 8 B and, to a lesser extent, in 7 Be.

Weak and magnetic inelastic scattering of antineutrinos on atomic electrons

AbstractNeutrino scattering on electrons is considered as a tool for laboratory searches for the neutrino magnetic moment. Inelastic n

Pairing-induced localization of the particle continuum in weakly bound nuclei

bar nu _e e^ -

New soft mode in the 11Li nucleus excited through (p,p′) reaction

n scattering on electrons bound in the germanium (Z=32) and iodine (Z=53) atoms is studied for antineutrinos generated in a nuclear reactor core and in 90Sr-90Y and 147Pm artificial sources. On the basis of the relativistic Hartree-Fock-Dirac model, both the magnetic-and weak-scattering cross sections are calculated for the recoil electron energy range between 1 and 100 keV, where a higher sensitivity to the neutrino magnetic moment could be achieved. Particular attention is paid to an approximate procedure that allows us to take into account the effects of atomic binding on the inelastic-scattering spectra in a simple way.