234 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
Hard Photons Beyond Proton-Neutron Bremsstrahlung in Heavy-Ion Collisions
We report on the study of extremely high energy photons, pions and etas,
produced in intermediate energy heavy-ion collisions. Possibility of imaging
the final-state phase space in these collisions by the Bose-Einstein
correlations for photons is critically examined.Comment: 11 pages, 4 figures, Invited talk at the NATO Advanced Research
Workshop on the Structure of Mesons, Baryons and Nuclei, Krakow (Poland), May
26 - 30, 199
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
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
Approximate solution of the pairing Hamiltonian in the Berggren basis
We derive the approximate solution for the pairing Hamiltonian in the
Berggren ensemble of single particle states including bound, resonance and
non-resonant scattering states. We show that this solution is reliable in the
limit of a weak pairing interaction
Weakly bound systems, continuum effects, and reactions
Structure of weakly bound/unbound nuclei close to particle drip lines is
different from that around the valley of beta stability. A comprehensive
description of these systems goes beyond standard Shell Model and demands an
open quantum system description of the nuclear many-body system. We approach
this problem using the Gamow Shell Model which provides a fully microscopic
description of bound and unbound nuclear states, nuclear decays, and reactions.
We present in this paper the first application of the GSM for a description of
the elastic and inelastic scattering of protons on 6He.Comment: Proc. Int. Conf. "Horizons of Innovative Theories, Experiments and
Supercomputing in Nuclear Physics", June 4-7, 2012, New Orleans, Luisiana,
USA; 10 pages, 4 figure
Isospin mixing and the continuum coupling in weakly bound nuclei
The isospin breaking effects due to the Coulomb interaction in weakly-bound
nuclei are studied using the Gamow Shell Model, a complex-energy configuration
interaction approach which simultaneously takes into account many-body
correlations between valence nucleons and continuum effects. We investigate the
near-threshold behavior of one-nucleon spectroscopic factors and the structure
of wave functions along an isomultiplet. Illustrative calculations are carried
out for the T=1 isobaric triplet. By using a shell-model Hamiltonian consisting
of an isoscalar nuclear interaction and the Coulomb term, we demonstrate that
for weakly bound or unbound systems the structure of isobaric analog states
varies within the isotriplet and impacts the energy dependence of spectroscopic
factors. We discuss the partial dynamical isospin symmetry present in
isospin-stretched systems, in spite of the Coulomb interaction that gives rise
to large mirror symmetry breaking effects.Comment: 10 pages, 5 figures ; published versio
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