The $B\to K^*$ form factors on the lattice
  The extraction of the $B\to K^*$ transition form factors from lattice data is studied, applying non-relativistic effective field theory in a finite volume. The possible mixing of $\pi K$ and $\eta K$ states is taken into account. The two-channel analogue of the Lellouch-L\"uscher formula is reproduced. Due to the resonance nature of the $K^*$, an equation is derived, which allows to determine the form factors at the pole position in a process-independent manner. The infinitely-narrow width approximation of the results is discussed. 
Andria Agadjanov (Bonn U. and Bonn U., HISKP), V\'eronique Bernard   (Orsay, IPN), Ulf-G. Mei{\ss}ner (Bonn U. and Bonn U., ...
hep-lat hep-ph