80 research outputs found
EFFECT OF THE CASIMIR ENERGY ON THE BAG MODEL PHENOMENOLOGY OF LIGHT HADRONS
The dependence of light hadron masses and baryon magnetic moments on the magnitude of the Casimir energy is examined in the bag model with centre-of-mass corrections. There are seven free parameters in the model. Six of them are determined from the fit to the masses of certain hadrons, and the last one (Casimir energy parameter) from the best fit to the magnetic moments of light baryons. The predicted magnetic moments are compared with the results obtained in various other models and with experiment data
Heavy hadron spectroscopy and the bag model
Some time ago a slightly improved variant of bag model (the modified bag
model) suitable for the unified description of light and heavy hadrons was
developed. The main goal of the present work was to calculate the masses of the
ground state baryons containing bottom quarks in the framework of this model.
For completeness the predictions for other heavy hadrons are also given. The
reasonable agreement of our results with other theoretical calculations and
available experimental data suggests that our predictions could serve as a
useful complementary tool for the interpretation of heavy hadron spectra.Comment: 18 pages, 9 tables, references to experiments updated, rms deviations
given in some table
Spin-other-orbit operator in the tensorial form of second quantization
The tensorial form of the spin-other-orbit interaction operator in the
formalism of second quantization is presented. Such an expression is needed to
calculate both diagonal and off-diagonal matrix elements according to an
approach, based on a combination of second quantization in the coupled
tensorial form, angular momentum theory in three spaces (orbital, spin and
quasispin), and a generalized graphical technique. One of the basic features of
this approach is the use of tables of standard quantities, without which the
process of obtaining matrix elements of spin-other-orbit interaction operator
between any electron configurations is much more complicated. Some special
cases are shown for which the tensorial structure of the spin-other-orbit
interaction operator reduces to an unusually simple form
Isoscalar Hamiltonians for light atomic nuclei
The charge-dependent realistic nuclear Hamiltonian for a nucleus, composed of
neutrons and protons, can be successfully approximated by a charge-independent
one. The parameters of such a Hamiltonian, i.e., the nucleon mass and the NN
potential, depend upon the mass number A, charge Z and isospin quantum number T
of state of the studied nucleus.Comment: REVTeX, 22 pages, 3 eps figures, to appear in PR
Towards the unified description of light and heavy hadrons in the bag model approach
Mass spectra of ground state hadrons containing u-, d-, s-, c-quarks as well
as some lightest hadrons containing b-quarks are calculated on the basis of a
slightly modified bag model. The center-of-mass motion corrections are
incorporated using a wavepacket projection with Gaussian parametrization of the
distribution amplitude. We use running coupling constant and also allow the
effective quark mass to be scale-dependent. The impact of these modifications
on the hadron mass spectrum is investigated. A comparison of the predicted mass
values with the experimental data demonstrates that the modified bag model is
sufficiently flexible to provide a satisfactory description of light and heavy
hadrons (mesons and baryons) in a single consistent framework.Comment: 27 pages, 11 table
A Sturm-Liouville problem for realistic internucleon potentials
ISSN 0024-2969 - neteisingas; nuo 2003 m. - ISSN 1648-8504Fizikos instituta
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