156 research outputs found
The gluon/charm content of the eta' meson and instantons
Motivated by recent CLEO measurements of the B-->\eta' K decay, we evaluate
gluon/charm content of the eta' meson using the interacting instanton liquid
model of the QCD vacuum. Our result is very large due to the strong field of
small-size instantons. We show that it provides quantitative explanations of
the CLEO data on the B-->\eta' K decay rate (as well as inclusive process
B-->\eta' X), via a virtual Cabbibo-unsuppressed decay into \bar c c pair which
then becomes eta'. If so, a significant charm component should be present in
other hadrons also. In particular, we found a large contribution of the charmed
quark in the polarised deep-inelastic scattering on a proton.Comment: 6 pages, LATE
reaction near threshold
We analyze the total cross section data for near threshold
measured recently at SATURNE. Using an effective range approximation for the
on-shell S-wave final state interaction we extract from these data the
modulus fm of the threshold transition amplitude
. We present a calculation of various (tree-level) meson exchange
diagrams contributing to . It is essential that -emission from
the anomalous -vertex interferes destructively with
-emission from the proton lines. The contribution of scalar
-meson exchange to turns out to be negligibly small. Without
introducing off-shell meson-nucleon form factors the experimental value
fm can be reproduced with an -coupling constant
of . The results of the present approach agree qualitatively
with the J\"ulich model. We also perform a combined analysis of the reactions
and near threshold.Comment: Latex-file 6 pages, 2 Figure
One-rank interaction kernel of the two-nucleon system for medium and high energies
A new version of the separable kernel of the nucleon-nucleon interaction in
the Bethe-Salpeter approach is presented. The phase shifts are fitted to recent
experimental data for singlet and uncoupled triplet partial waves of the
neutron-proton scattering with total angular momenta J=0,1. The results are
compared with other model calculations.Comment: 10 pages, 5 figures, 3 table
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