2019 Impact factor 4.389
Particles and Fields
Eur. Phys. J. C 5, 517-524
DOI 10.1007/s100529800858

${\cal O}(\alpha_s^2)$ corrections to $b \to c$ decay at zero recoil

J. Franzkowski1 - J.B. Tausk2

1 Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, D-55099 Mainz, Germany
Fakultät für Physik, 2 Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany

Received: 10 December 1997 / Published online: 10 March 1998

Abstract
Analytic formulae are presented for the two-loop perturbative QCD corrections to $b \to c$ decay at the zero recoil point, which are required for the extraction of |Vbc| from measurements of exclusive $B\to D^* l \nu$ decays. The results are in agreement with those in [8,9]. Some comments on the numerical evaluation of the diagrams involved are made.


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