Zero-Recoil Sum Rules for $Î_b \to Î_c$ Form Factors
arXiv:1506.08780 · doi:10.1016/j.physletb.2015.10.016
Abstract
We set up a zero recoil sum rule to constrain the form factors of the $Î_b \to Î_c$ transition. Our results are compared with the recent lattice calculation for these transitions. We find the same situation as in the case for $B \to D^*$: The lattice results practically saturate the sum rules, leaving basically no room for excited states.
8 pages, 5 figures