https://doi.org/10.1140/epja/i2009-10893-3
Regular Article - Theoretical Physics
Semileptonic form factors D 
, K and B
, K from a fine lattice
1
Department of Physics, Faculty of Science, Taiz University, Taiz, Yemen
2
Institute for Theoretical Physics, University of Regensburg, 93040, Regensburg, Germany
3
INFN, Sezione di Milano, 20133, Milano, Italy
4
Institute for Theoretical Physics, ETH Zürich, 8093, Zürich, Switzerland
5
Deutsches Elektronen-Synchrotron DESY, 22603, Hamburg, Germany
* e-mail: panero@phys.ethz.ch
Received:
7
August
2009
Revised:
15
October
2009
Accepted:
23
October
2009
Published online:
20
November
2009
We extract the form factors relevant for semileptonic decays of D and B mesons from a relativistic computation on a fine lattice in the quenched approximation. The lattice spacing is a = 0.04 fm (corresponding to a
-1 = 4.97 GeV), which allows us to run very close to the physical B meson mass, and to reduce the systematic errors associated with the extrapolation in terms of a heavy-quark expansion. For decays of D and Ds mesons, our results for the physical form factors at 
are as follows: 
, 
and 
. Similarly, for B and Bs we find 
, 
and 
. We compare our results with other quenched and unquenched lattice calculations, as well as with light-cone sum rule predictions, finding good agreement.
© SIF, Springer-Verlag Berlin Heidelberg, 2010
