6 research outputs found
Non-factorizable long distance contributions in color suppressed decays of B mesons
, , and decays are
studied. Their amplitude is given by a sum of factorized and non-factorizable
ones. The latter which is estimated by using a hard pion approximation is
rather small in color favored and decays but still
can efficiently interfere with the main amplitude given by the factorization.
In the color suppressed and decays, the
non-factorizable contribution is very important. The sum of the factorized and
non-factorizable amplitudes can reproduce well the existing experimental data
on the branching ratios for the color favored and
and the color suppressed and decays by
taking reasonable values of unknown parameters involved.Comment: 19 pages, Revte
Supersymmetric Yang-Mills theory on conformal supergravity backgrounds in ten dimensions
We consider bosonic supersymmetric backgrounds of ten-dimensional conformal
supergravity. Up to local conformal isometry, we classify the maximally
supersymmetric backgrounds, determine their conformal symmetry superalgebras
and show how they arise as near-horizon geometries of certain half-BPS
backgrounds or as a plane-wave limit thereof. We then show how to define
Yang-Mills theory with rigid supersymmetry on any supersymmetric conformal
supergravity background and, in particular, on the maximally supersymmetric
backgrounds. We conclude by commenting on a striking resemblance between the
supersymmetric backgrounds of ten-dimensional conformal supergravity and those
of eleven-dimensional Poincar\'e supergravity.Comment: 30 page