Ball, P. and Zwicky, R. (2001) 'Improved analysis of B → πeν from QCD sum rules on the light-cone.', Journal of high energy physics., 10 . p. 19.
We present a new calculation of the Brightarrowpi form-factor f+, relevant for the measurement of |Vub| from semileptonic Brightarrowpi transitions, from QCD sum rules on the light-cone. The new element is the calculation of radiative corrections to next-to-leading twist-3 accuracy. We find that these contributions are factorizable at O(alphas), which lends additional support to the method of QCD sum rules on the light-cone. We obtain f+(0) = 0.26+/-0.06+/-0.05, where the first error accounts for the uncertainty in the input-parameters and the second is a guesstimate of the systematic uncertainty induced by the approximations inherent in the method. We also obtain a simple parametrization of the form-factor which is valid in the entire kinematical range of semileptonic decays and consistent with vector-meson dominance at large momentum-transfer.
|Keywords:||Standard model, Weak decays, B-physics, Sum rules.|
|Full text:||PDF - Other (193Kb)|
|Publisher Web site:||http://dx.doi.org/10.1088/1126-6708/2001/10/019|
|Record Created:||07 May 2008|
|Last Modified:||05 Aug 2011 16:43|
|Social bookmarking:||Export: EndNote, Zotero | BibTex|
|Usage statistics||Look up in GoogleScholar | Find in a UK Library|