Orateur
M.
Alexander Khodjamirian
(Siegen University)
Description
I will report on the QCD calculation of the hadronic matrix elements
relevant for the exclusive rare $B$ decays, such as
$B\to K^{(*)}\ell^+\ell^-$ and $B\to K^*\gamma$.
The hadronic input for the decay observables,
in addition to the heavy-light form factors,
contains specific contributions, generated by the four-quark
and penguin operators, such as the charm-loop effects.
The corresponding hadronic matrix elements
are calculated by the same method as the form factors, applying OPE and
light-cone sum rules in QCD. This technique allows one to
take into account the nonfactorizable soft-gluon contributions.
The results are expressed in terms of (process-dependent) corrections
to the short-distance coefficients of the effective Hamiltonian.
The impact of these corrections on the most important observables, e.g., on
the forward-backward asymmetry in $B\to K^* \ell^+\ell^-$, is estimated.
Auteur principal
M.
Alexander Khodjamirian
(Siegen University)
