Speaker
Alexander Khodjamirian
(University of Siegen)
Description
I will present new results
on the theory of the rare flavour-changing neutral-current
decay $B\to \pi\ell^+\ell^-$ in the region of large recoil of the pion.
Nonlocal hadronic effects
in this decay are treated in a systematic way, combining QCD calculation with hadronic
dispersion relation including the vector meson contributions.
The effective addition to the Wilson coefficient $C_9$ is calculated in the region $0 \leq q^2 \leq m_{J/\psi}^2$ of the lepton-pair invariant mass. This result, together with
the updated $B\to \pi$ form factor from light-cone sum rules,
is used to predict the rate, $CP$-asymmetry and isospin-asymmetry
in $B\to \pi\ell^+\ell^-$ in the Standard Model.
The influence of hypothetical new physics in $b\to d \ell^+\ell^- $ transitions on these
observables, as well as the expectations for similar exclusive FCNC decays will be also
discussed.
Author
Alexander Khodjamirian
(University of Siegen)
