157,079 research outputs found
Symplectic harmonicity and generalized coeffective cohomologies
Relations between the symplectically harmonic cohomology and the coeffective
cohomology of a symplectic manifold are obtained. This is achieved through a
generalization of the latter, which in addition allows us to provide a
coeffective version of the filtered cohomologies introduced by C.-J. Tsai,
L.-S. Tseng and S.-T. Yau. We construct closed (simply connected) manifolds
endowed with a family of symplectic forms such that the dimensions
of these symplectic cohomology groups vary with respect to . A complete
study of these cohomologies is given for 6-dimensional symplectic nilmanifolds,
and concrete examples with special cohomological properties are obtained on an
-dimensional solvmanifold and on 2-step nilmanifolds in higher dimensions.Comment: 25 pages; revised version, new Theorem 5.7 and Section 8 added,
references update
Tetramixing of vector and pseudoscalar mesons: A source of intrinsic quarks
The tetramixing of pseudoscalar mesons --- and
vector mesons --- are studied in the light-cone
constituent quark model, and such mixing of four mesons provides a natural
source for the intrinsic charm components of light mesons. By mixing
with the light mesons, the charmonium states and could decay
into light mesons more naturally, without introducing gluons or a virtual
photon as intermediate states. Thus, the introduction of light quark components
into is helpful to reproduce the new experimental data of
decays. The mixing matrices and the behaviors of the transition form
factors are also calculated and compared with experimental data.Comment: 20 pages, 10 figures. Version for publication in PR
Study of , Decays with QCD Factorization
The , decays are studied in
the scheme of the QCD factorization approach. The branching ratios are
calculated with the asymptotic distribution amplitude of the pion. The charm
quark mass effect is considered. We find that the mass effect on the branching
ratios is small.Comment: 20 pages, 3 figures, 3 table
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