60 research outputs found
Pentaquark spectrum in string dynamics
The masses of and pentaquarks are evaluated in a
framework of the Effective Hamiltonian approach to QCD using the Jaffe-Wilczek
approximation. The mass of the state is found to
be MeV higher than the observed mass.Comment: 6 pages, 1 figure included, LaTeX2e; several references added;
misprints corrected; to appear in Physics Letters
Pentaquarks in string dynamics
The masses of , , and pentaquarks are
evaluated in a framework of both the Effective Hamiltonian approach to QCD and
spinless Salpeter using the Jaffe-Wilczek diquark approximation and the string
interaction for the diquark-diquark-antiquark system. The masses of the light
pentaquarks are found to be in the region above 2 GeV. The similar calculations
yield the mass of pentaquark 3250 MeV and
pentaquark 6509 MeV.Comment: 5 pages. Based on talk by I.M.Narodetskii at BEACH 2004, 6th
International Conference on Hyperons, Charm and Beauty Hadrons, Illionois
Institute of Technology, Chicago, June. 27 - July 3, 2004. Typos correcte
The doubly heavy baryons
We present the results for the masses of the doubly heavy baryons
and where obtained in the framework of the simple
approximation within the nonperturbative string approach.Comment: 4 pages, 1 EPS fig., using espcrc2.sty package. Talk presented by
I.M.Narodetskii at the 5th International Conference on Hyperon, Charm and
Beauty Hadrons, Vancouver, Canada, June 200
Accuracy of Auxiliary Field Approach for Baryons
We provide a check of the accuracy of the auxiliary field formalism used to
derive the Effective Hamiltonian for baryons in the Field Correlator Method. To
this end we compare the solutions for the Effective Hamiltonian with those
obtained from the solution of the Salpeter equation. Comparing these results
gives a first estimate of the systematic uncertainty due to the use of the
auxiliary field formalism for baryons.Comment: 6 pages, 2 tables; published versio
Auxiliary fields and hadron dynamics
The relations existing between the auxiliary field (einbein field) formalism
and the spinless Salpeter equation are studied in the case of two particles
with the same mass, interacting via a confining potential. The problem of
non-orthogonality for radial excited states in the auxiliary field formalism is
discussed and found to be non-crucial. It is shown that the classical equations
of motion of the rotating string model, derived from the QCD lagrangian, reduce
exactly to the classical equations of motion of the phenomenological
semirelativistic flux tube model, provided all auxiliary fields are eliminated
correctly from the rotating string hamiltonian
Confinement and Chiral Symmetry Breaking via Domain-Like Structures in the QCD Vacuum
A qualitative mechanism for the emergence of domain structured background
gluon fields due to singularities in gauge field configurations is considered,
and a model displaying a type of mean field approximation to the QCD partition
function based on this mechanism is formulated. Estimation of the vacuum
parameters (gluon condensate, topological susceptibility, string constant and
quark condensate) indicates that domain-like structures lead to an area law for
the Wilson loop, nonzero topological susceptibility and spontaneous breakdown
of chiral symmetry. Gluon and ghost propagators in the presence of domains are
calculated explicitly and their analytical properties are discussed. The
Fourier transforms of the propagators are entire functions and thus describe
confined dynamical fields.Comment: RevTeX, 48 pages (32 pages + Appendices A-E), new references added
[1,2,4,5] and minor formulae corrected for typographical error
Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts
Phase transition from hadronic matter to quark-gluon matter is discussed for
various regimes of temperature and baryon number density. For small and medium
densities, the phase transition is accurately described in the framework of the
Field Correlation Method, whereas at high density predictions are less certain
and leave room for the phenomenological models. We study formation of
multiquark states (MQS) at zero temperature and high density. Relevant MQS
components of the nuclear matter can be described using a previously developed
formalism of the quark compound bags (QCB).
Partial-wave analysis of nucleon-nucleon scattering indicates the existence
of 6QS which manifest themselves as poles of -matrix. In the framework of
the QCB model, we formulate a self-consistent system of coupled equations for
the nucleon and 6QS propagators in nuclear matter and the G-matrix. The
approach provides a link between high-density nuclear matter with the MQS
components and the cumulative effect observed in reactions on the nuclei, which
requires the admixture of MQS in the wave functions of nuclei kinematically.
6QS determine the natural scale of the density for a possible phase
transition into the MQS phase of nuclear matter. Such a phase transition can
lead to dynamic instability of newly born protoneutron stars and dramatically
affect the dynamics of supernovae. Numerical simulations show that the phase
transition may be a good remedy for the triggering supernova explosions in the
spherically symmetric supernova models. A specific signature of the phase
transition is an additional neutrino peak in the neutrino light curve. For a
Galactic core-collapse supernova, such a peak could be resolved by the present
neutrino detectors. The possibility of extracting the parameters of the phase
of transition from observation of the neutrino signal is discussed also.Comment: 57 pages, 22 figures, 7 tables; RevTeX 4; submitted to Phys. Atom.
Nuc
- …