743 research outputs found
Once more on electromagnetic form factors of nucleons in extended vector meson dominance model
Extended vector meson dominance model, that allows to describe the
electromagnetic form factors of nucleons obeying the asymptotic quark counting
rule prescriptions and contains the minimal number of free parameters, is
presented. We get a reasonable fit of form factors over experimentally
available space-like region of momentum transfer and get also reasonable
results in the time-like region.Comment: 7 pages, 2 figure
Dibaryon Condensate in Nuclear Matter and Neutron Stars: Exact Analysis in One-Dimensional Models
We investigate dense nuclear matter with a dibaryon Bose-Einstein condensate
as a possible intermediate state before the quark-gluon phase transition. An
exact analysis of this state of matter is presented in a one-dimensional model.
The analysis is based on a reduction of the quantization rules for the N-body
problem to N coupled algebraic transcendental equations. We observe that when
the Fermi momentum approaches the resonance momentum, the one-particle
distribution function increases near the Fermi surface. When the Fermi momentum
is increased beyond the resonance momentum, the equation of state becomes
softer. The observed behavior can be interpreted in terms of formation of a
Bose-Einstein condensate of two-fermion resonances (dibaryons). In cold nuclear
matter, it should occur if 2(m_N + epsilon_F) is greater or equal to m_D, where
m_N and m_D are respectively the nucleon and dibaryon masses and epsilon_F is
the nucleon Fermi energy.Comment: 25 pages, LaTeX, 2 Postscript figures, to appear in Annals of Physic
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