367 research outputs found
Self-consistent Theory of Finite Fermi Systems vs Skyrme-Hartree-Fock method. Spherical nuclei
Recent results of the Fayans energy density functional (EDF) for spherical
nuclei are reviewed. A comparison is made with predictions of several Skyrme
EDFs. The charge radii and characteristics of the first 2^+ excitations in
semi-magic nuclei are briefly discussed. The single-particle spectra of doubly
magic nuclei are considered in more detail. The phonon-particle coupling
effects are analyzed including the so-called tadpole term.Comment: 6 pages, 7 figures, to appear in the proceedings of the International
Conference "Nuclear Structure and Relaited Topics", July 14 - July 18, 2015,
Dubna, Russia. arXiv admin note: text overlap with arXiv:1401.131
Particle-phonon coupling effects within theory of finite Fermi systems
Recent results of the study of the particle-phonon coupling (PC) effects in
odd magic and semi-magic nuclei within the self-consistent theory of finite
Fermi systems are reviewed. In addition to the usual pole diagrams, the
non-pole ones are considered. Their contributions are often of a crucial
importance. PC corrections to the single-particle energies for Ca and
Pb are presented. The quadrupole moments of odd In and Sb isotopes, the
odd-proton neighbors of even Sn isotopes, are presented also with accounting
for the PC corrections. At last, recently announced problem of extremely high
values charge radii of heavy Ca isotopes is solved in terms of a consistent
consideration of the PC effects. In all the cases, rather good description of
the data is obtained.Comment: 10 pages, 6 figures, to appear in the proceedings of the Fifth
Conference on NUCLEI and MESOSCOPIC Physics (NMP17), March 6-10, 2017; East
Lansing, Michigan, US
An ab initio theory of double odd-even mass differences in nuclei
Two aspects of the problem of evaluating double odd-even mass differences D_2
in semi-magic nuclei are studied related to existence of two components with
different properties, a superfluid nuclear subsystem and a non-superfluid one.
For the superfluid subsystem, the difference D_2 is approximately equal to
2\Delta, the gap \Delta being the solution of the gap equation. For the
non-superfluid subsystem, D_2 is found by solving the equation for two-particle
Green function for normal systems. Both equations under consideration contain
the same effective pairing interaction. For the latter, the semi-microscopic
model is used in which the main term calculated from the first principles is
supplemented with a small phenomenological addendum containing one
phenomenological parameter supposed to be universal for all medium and heavy
atomic nuclei.Comment: 7 pages, 10 figures, Report at Nuclear Structure and Related Topics,
Dubna, Russia, July 2 - July 7, 201
Magnetic moments of odd-odd spherical nuclei
Magnetic moments of more than one hundred odd-odd spherical nuclei in ground
and excited states are calculated within the self-consistent TFFS based on the
EDF method by Fayans {\it et al}. We limit ourselves to nuclei with a neutron
and a proton particle (hole) added to the magic or semimagic core. A simple
model of no interaction between the odd nucleons is used. In most the cases we
analyzed, a good agreement with the experimental data is obtained. Several
cases are considered where this simple model does not work and it is necessary
to go beyond. The unknown values of magnetic moments of many unstable odd and
odd-odd nuclei are predicted including sixty values for excited odd-odd nuclei.Comment: 10 page
Self-consistent account for phonon induced corrections to quadrupole moments of odd nuclei. Pole and non-pole diagrams
Recent results of the description of quadrupole moments of odd semi-magic
nuclei are briefly reviewed. They are based on the self-consistent theory of
finite Fermi systems with account for the phonon-particle coupling (PC)
effects. The self-consistent model for describing the PC effects was developed
previously for magnetic moments. Account for the non-pole diagrams is an
important ingredient of this model. In addition to previously reported results
for the odd In and Sb isotopes, which are the proton-odd neighbors of even tin
nuclei, we present new results for odd Bi isotopes, the odd neighbors of even
lead isotopes. In general, account for the PC corrections makes the agreement
with the experimental data significantly better.Comment: 8 pages, 4 figures. Presented at ICNFP1
Phonon coupling effects in magnetic moments of magic and semi-magic nuclei
Phonon coupling (PC) corrections to magnetic moments of odd neighbors of
magic and semi-magic nuclei are analyzed within the self-consistent Theory of
Finite Fermi Systems (TFFS) based on the Energy Density Functional by Fayans et
al. The perturbation theory in g_L^2 is used where g_L is the phonon-particle
coupling vertex. A model is developed with separating non-regular PC
contributions, the rest is supposed to be regular and included into the
standard TFFS parameters. An ansatz is proposed to take into account the
so-called tadpole term which ensures the total angular momentum conservation
with g_L^2 accuracy. An approximate method is suggested to take into account
higher order terms in g_L^2. Calculations are carried out for four odd-proton
chains, the odd Tl, Bi, In and Sb ones. Different PC corrections strongly
cancel each other. In the result, the total PC correction to the magnetic
moment in magic nuclei is, as a rule, negligible. In non-magic nuclei
considered it is noticeable and, with only one exception, negative. On average
it is of the order of -(0.1 - 0.5) \mu_N and improves the agreement of the
theory with the data. Simultaneously we calculated the gyromagnetic ratio
g_L^{ph} of all low-lying phonons in 208Pb. For the 3^-_1 state it is rather
close to the Bohr-Mottelson model prediction whereas for other L-phonons, two
5^- and six positive parity states, the difference from the Bohr-Mottelson
values is significant.Comment: 21 pages, 24 figure
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