879 research outputs found
Nucleon-nucleon resonances at intermediate energies using a complex energy formalism
We apply our method of complex scaling, valid for a general class of
potentials, in a search for nucleon-nucleon S-matrix poles up to 2 GeV
laboratory kinetic energy. We find that the realistic potentials JISP16,
constructed from inverse scattering, and chiral field theory potentials NLO
and NLO support resonances in energy regions well above their fit
regions. In some cases these resonances have widths that are narrow when
compared with the real part of the S-matrix pole.Comment: 7 pages, 5 figures, 2 Table
No-core shell model for 48-Ca, 48-Sc and 48-Ti
We report the first no-core shell model results for , and
with derived and modified two-body Hamiltonians. We use an oscillator
basis with a limited range around and a limited model space up to . No single-particle
energies are used. We find that the charge dependence of the bulk binding
energy of eight A=48 nuclei is reasonably described with an effective
Hamiltonian derived from the CD-Bonn interaction while there is an overall
underbinding by about 0.4 MeV/nucleon. However, the resulting spectra exhibit
deficiencies that are anticipated due to: (1) basis space limitations and/or
the absence of effective many-body interactions; and, (2) the absence of
genuine three-nucleon interactions. We then introduce additive
isospin-dependent central terms plus a tensor force to our Hamiltonian and
achieve accurate binding energies and reasonable spectra for all three nuclei.
The resulting no-core shell model opens a path for applications to the
double-beta () decay process.Comment: Revised content and added reference
Structure of A = 7 - 8 nuclei with two- plus three-nucleon interactions from chiral effective field theory
We solve the ab initio no-core shell model (NCSM) in the complete Nmax = 8
basis for A = 7 and A = 8 nuclei with two-nucleon and three-nucleon
interactions derived within chiral effective field theory (EFT). We find that
including the chiral EFT three-nucleon interaction in the Hamiltonian improves
overall good agreement with experimental binding energies, excitation spectra,
transitions and electromagnetic moments. We predict states that exhibit
sensitivity to including the chiral EFT three-nucleon interaction but are not
yet known experimentally.Comment: 10 pages, 6 figures, updated references and corrected a typ
Emergence of rotational bands in ab initio no-core configuration interaction calculations of light nuclei
The emergence of rotational bands is observed in no-core configuration
interaction (NCCI) calculations for the odd-mass Be isotopes (7<=A<=13) with
the JISP16 nucleon-nucleon interaction, as evidenced by rotational patterns for
excitation energies, quadrupole moments, and E2 transitions. Yrast and
low-lying excited bands are found. The results demonstrate the possibility of
well-developed rotational structure in NCCI calculations using a realistic
nucleon-nucleon interaction.Comment: 7 pages, 6 figures; to be published in Phys. Lett.
Boundary between Hadron and Quark/Gluon Structure of Nuclei
We show that the boundary between quark-dominated and hadron-dominated
regions of nuclear structure may be blurred by multi-nucleon quark clusters
arising from color percolation. Recent experiments supporting partial
percolation in cold nuclei and full percolation in hot/dense nuclear matter
include: deep inelastic lepton-nucleus scattering, relativistic heavy-ion
collisions and the binding energy in .Comment: 10 pages, 4 figures; added references; improved figures; fixed a typo
(wrong sign in Eqn 6); Fixed typos in Equation 2; updated reference
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