10,965 research outputs found
^1S_0 pairing correlations in relativistic nuclear matter and the two-nucleon virtual state
We use the Gorkov formulation of the Dirac-Hartree-Fock-Bogoliubov
approximation to nuclear pairing to study the ^1S_0 nucleon-nucleon
correlations in nuclear matter. We find the short-range correlations of the
^1S_0 pairing fields to be almost identical to those of the two-nucleon virtual
state. We obtain mutually consistent results for the pairing fields, using
several different sets of effective interaction parameters, when we demand that
each of these sets places the virtual-state pole at its physical location.Comment: 11 pages, 9 PostScript figures, RevTex, submitted to Phys. Rev.
Elastic and inelastic breakup of deuterons with energy below 100 MeV
We present calculations of deuteron elastic and inelastic breakup cross
sections and angular distributions at deuteron energies below 100 MeV obtained
using the post-form DWBA approximation. The elastic breakup cross section was
extensively studied in the past. Very few calculations of inelastic breakup
have been performed, however. We also analyze the angular momentum - energy
distributions of the cross section for formation of the compound nucleus after
inelastic breakup.Comment: 7 page
Effective Widths and Effective Number of Phonons of Multiphonon Giant Resonances
We discuss the origin of the difference between the harmonic value of the
width of the multiphonon giant resonances and the smaller observed value.
Analytical expressions are derived for both the effective width and the average
cross-section. The contribution of the Brink-Axel mechanism in resolving the
discrepancy is pointed out.Comment: 9 pages, 4 figure
Statistical features of the thermal neutron capture cross sections
We discuss the existence of huge thermal neutron capture cross sections in
several nuclei. The values of the cross sections are several orders of
magnitude bigger than expected at these very low energies. We lend support to
the idea that this phenomenon is random in nature and is similar to what we
have learned from the study of parity violation in the actinide region. The
idea of statistical doorways is advanced as a unified concept in the
delineation of large numbers in the nuclear world. The average number of maxima
per unit mass, in the capture cross section is calculated and related
to the underlying cross section correlation function and found to be , where is a characteristic mass
correlation width which designates the degree of remnant coherence in the
system. We trace this coherence to nucleosynthesis which produced the nuclei
whose neutron capture cross sections are considered here.Comment: 7 pages, 6 figures. To appear in Acta Physica Polonica B as a
Contribution to the proceedings of:Jagiellonian Symposium of Fundamental and
Applied Subatomic Physics, June 7- 12, 2015 Krakow, Polan
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