48 research outputs found
Features of exceptional points and the continuum spectroscopy
We discuss observable features of exceptional points and the resonance
spectroscopy of Ne using the Shell Model Embedded in the Continuum.Comment: 10 pages, 4 figures Zakopane Conference on Nuclear Physics, September
1-7, 2008, Zakopane, Polan
Structure of many-body continuum states in the proximity of exceptional points
We demonstrate existence of exceptional points in many-body scattering
continuum of atomic nucleus and discuss their salient effects on the example of
one-nucleon spectroscopic factors.Comment: 5 pages, 4 figure
Unexpected features of quantum degeneracies in a pairing model with two integrable limits
The evolution pattern of level crossings and exceptional points is studied in
a non-integrable pairing model with two different integrable limits. One of the
integrable limits has two independent parameter-dependent integrals of motion.
We demonstrate, and illustrate in our model, that quantum integrability of a
system with more than one parameter-dependent integral of motion is always
signaled by level crossings of a complex-extended Hamiltonian. We also find
that integrability implies a reduced number of exceptional points. Both
properties could uniquely characterize quantum integrability in small Hilbert
spaces.Comment: 4 pages, 2 figure
On the origin of nuclear clustering
Clustering is one of the most complex phenomena known to the structure of
atomic nuclei. A comprehensive description of this ubiquitous phenomenon goes
beyond standard shell model and cluster model frameworks. We argue that
clustering is a consequence of an openness of the nuclear many-body system. To
illustrate this point, we study the near-threshold behavior of exceptional
points in ^16 Ne and ^24 S.Comment: Proceedings "Frontier Issues in Physics of Exotic Nuclei"
(YKIS2011/DCEN2011), 14 pages, 9 figure
Continuum Coupling Effects in Spectra of Mirror Nuclei and Binding Systematics
Continuum-coupling correction to binding energies in neutron rich oxygen and
fluorine isotopes and to excitation energies of 2+ states in 36Ca and 36S
mirror nuclei are studied using the real-energy continuum shell model.Comment: Proc. XXX Mazurian Lakes Conference on Physics: Nuclear Physics and
Fundamental Processes 15 pages, 5 figure
Shell Model Embedded in the Continuum for Binding Systematics in Neutron-Rich Isotopes of Oxygen and Fluor
Continuum coupling correction to binding energies in the neutron rich oxygen and fluorine isotopes is studied using the Shell Model Embedded in the Continuum. We discuss the importance of different effects, such as the position of one-neutron emission threshold, the effective interaction or the number of valence particles on the magnitude of this correction
Statistical aspects of nuclear coupling to continuum
Various global characteristics of the coupling between the bound and scattering states are explicitly studied based on realistic Shell Model Embedded in the Continuum. In particular, such characteristics are related to those of the scattering ensemble. It is found that in the region of higher density of states the coupling to continuum is largely consistent with the statistical model. However, assumption of channel equivalence in the statistical model is, in general, violated
Microscopic Description of Nuclear Fission Dynamics
We discuss possible avenues to study fission dynamics starting from a
time-dependent mean-field approach. Previous attempts to study fission dynamics
using the time-dependent Hartree-Fock (TDHF) theory are analyzed. We argue that
different initial conditions may be needed to describe fission dynamics
depending on the specifics of the fission phenomenon and propose various
approaches towards this goal. In particular, we provide preliminary
calculations for studying fission following a heavy-ion reaction using TDHF
with a density contraint. Regarding prompt muon-induced fission, we also
suggest a new approach for combining the time-evolution of the muonic wave
function with a microscopic treatment of fission dynamics via TDHF
A study of nuclei of astrophysical interest in the continuum shell model
We present here the first application of realistic shell model (SM) including
coupling between many-particle (quasi-)bound states and the continuum of
one-particle scattering states to the spectroscopy of 8B and to the calculation
of astrophysical factors in the reaction 7Be(p,gamma)8B.Comment: 9 pages incl. 3 figures, LaTeX with iopart class and epsf. Invited
talk at the Int. Workshop on Physics with Radioactive Nuclear Beams, Jan.
12-17, 1998, Puri, India. Shortened version will be published in proceedings
to apear as a separate J. Phys. G volum