2,976 research outputs found
Unitary Structure of the QCD Sum Rules and KYN and KY\Xi Couplings
New relations between QCD Borel sum rules for strong coupling constants of
K-mesons to baryons are derived. It is shown that starting from the sum rule
for the coupling constants and it
is straightforward to obtain corresponding sum rules for the , couplings, .Comment: 7 pages, 2 tables, International Workshop on Quantum
Chromodynamics:Theory and Experiment, QCD@Work-2005, Coversano(Bari, Italy),
16-20 June, 200
Zero range potential for particles interacting via Coulomb potential: application to electron positron annihilation
The zero range potential is constructed for a system of two particles
interacting via the Coulomb potential. The singular part of the asymptote of
the wave function at the origin which is caused by the common effect of the
zero range potential singularity and of the Coulomb potential is explicitly
calculated by using the Lippmann-Schwinger type integral equation. The singular
pseudo potential is constructed from the requirement that it enforces the
solution to the Coulomb Schr\"odinger equation to possess the calculated
asymptotic behavior at the origin. This pseudo potential is then used for
constructing a model of the imaginary absorbing potential which allows to treat
the annihilation process in positron electron collisions on the basis of the
non relativistic Schr\"odinger equation. The functional form of the pseudo
potential constructed in this paper is analogous to the well known
Fermi-Breit-Huang pseudo potential. The generalization of the optical theorem
on the case of the imaginary absorbing potential in presence of the Coulomb
force is given in terms of the partial wave series
Neutron star cooling after deep crustal heating in the X-ray transient KS 1731-260
We simulate the cooling of the neutron star in the X-ray transient KS
1731-260 after the source returned to quiescence in 2001 from a long (>~ 12.5
yr) outburst state. We show that the cooling can be explained assuming that the
crust underwent deep heating during the outburst stage. In our best theoretical
scenario the neutron star has no enhanced neutrino emission in the core, and
its crust is thin, superfluid, and has the normal thermal conductivity. The
thermal afterburst crust-core relaxation in the star may be not over.Comment: 5 pages, 2 figures, accepted by MNRAS. In v.2, two references added
and typos correcte
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