https://doi.org/10.1140/epjc/s2005-02360-4
Theoretical Physics
Impact of four-quark shape functions on inclusive B decay spectra
1
Institute for High-Energy Phenomenology, Newman Laboratory for Elementary-Particle Physics, Cornell University, NY 14853, Ithaca, USA
2
Institute for Advanced Study, School of Natural Sciences, NJ 08540, Princeton, USA
* e-mail: neubert@lepp.cornell.edu
It has recently been pointed out that a new class of subleading shape functions involving B-meson matrix elements of non-local four-quark operators contributes at order 
to 
decay distributions in the endpoint region. The corresponding functions 
and 
are estimated using the vacuum-insertion approximation. A numerical analysis of various decay spectra suggests that these power corrections are very small, below present theoretical uncertainties due to other subleading shape-function contributions.
© Springer-Verlag, 2005
