896 research outputs found
Production of -hypernuclei via the () reaction in a quark-meson coupling model
We study the production of -hypernuclei, Be and
Mg, via the () reaction within a covariant effective
Lagrangian model, employing the bound and proton spinors calculated by
the latest quark-meson coupling model. The present treatment yields the
differential cross sections for the formation of simple s-state
particle-hole states peak at a beam momentum around 1.0 GeV/c with a
value in excess of 1 b.Comment: Accepted version with miner changes, 4 pages, 2 figures, Presented at
the 20th International IUPAP Conference on Few-Body Problems in Physics, 20 -
25 August, 2012, Fukuoka, Japa
Binding of hypernuclei, and phtoproduction of -hypernuclei in the latest quark-meson coupling model
We study the binding of hypernuclei based on the latest version of
quark-meson coupling model, and estimate the phtoproduction cross sections for
the C()B reaction using the bound
spinors obtained in the model.Comment: 6 pages, 3 figures, Talk given at (Pre-symposium in) Sendai
International Symposium on Strangeness in Nuclear and Hadronic Systems
(SENDAI08), December (14)15-18, 2008, Tohoku Univ., Japa
Neutron Star Properties with Hyperons
In the light of the recent discovery of a neutron star with a mass accurately
determined to be almost two solar masses, it has been suggested that hyperons
cannot play a role in the equation of state of dense matter in
-equilibrium. We re-examine this issue in the most recent development of
the quark-meson coupling model. Within a relativistic Hartree-Fock approach and
including the full tensor structure at the vector-meson-baryon vertices, we
find that not only must hyperons appear in matter at the densities relevant to
such a massive star but that the maximum mass predicted is completely
consistent with the observation.Comment: Minor correction
Structure and Coulomb dissociation of 23O within the quark-meson coupling model
We study the ground-state structure of nuclei in the vicinity of the
one-neutron dripline within the latest version of the quark-meson coupling
(QMC) model with a particular emphasis on 23O. For this nucleus the model
predicts a [22O(0+) + n (2s_{1/2})] configuration for its ground state, with a
one neutron separation energy in close agreement with the corresponding
experimental value. The wave function describing the valence neutron-core
relative motion was then used to calculate the Coulomb dissociation of 23O on a
lead target at a beam energy of 422 MeV/nucleon. The experimental neutron-core
relative energy spectrum and the total one-neutron removal cross sections are
well described by the calculations. The widths of the longitudinal momentum
distributions of the 22O fragment are found to be broad, which do not support
the formation of a neutron halo in this nucleus.Comment: Revised and extended version, accepted for publication in Nucl. Phys.
Photoproduction of hypernuclei within the quark-meson coupling model
We study the photoproduction of the ^12{_Lambda}B hypernucleus within a fully
covariant effective Lagrangian based model, employing Lambda bound state
spinors derived from the latest quark-meson coupling model. The kaon production
vertex is described via creation, propagation and decay of N*(1650), N*(1710),
and N*(1720) intermediate baryonic resonant states in the initial collision of
the photon with a target proton in the incident channel. The parameters of the
resonance vertices are fixed by describing the total and differential cross
section data on the elementary gamma (p, K+) Lambda reaction in the energy
regime relevant to the hypernuclear production. It is found that the
hypernuclear production cross sections calculated with the quark model based
hyperon bound state spinors differ significantly from those obtained with the
phenomenological Dirac single particle wave functions.Comment: 16 pages, 5 figures, version to appear in Phys. Lett.
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