Pade/renormalization-group improvement of inclusive semileptonic B decay rates
Abstract
Renormalization Group (RG) and optimized Pade-approximant methods are used to estimate the three-loop perturbative contributions to the inclusive semileptonic b \to u and b \to c decay rates. It is noted that the \bar{MS} scheme works favorably in the b \to u case whereas the pole mass scheme shows better convergence in the b \to c case. Upon the inclusion of the estimated three-loop contribution, we find the full perturbative decay rate to be 192\pi^3\Gamma(b\to u\bar\nu_\ell\ell^-)/(G_F^2| V_{ub}|^2) = 2065 \pm 290{\rm GeV^5} and 192\pi^3\Gamma(b\to c\ell^-\bar\nu_\ell)/(G_F^2|V_{cb}|^2)= 992 \pm 198 {\rm GeV^5}, respectively. The errors are inclusive of theoretical uncertainties and non-perturbative effects. Ultimately, these perturbative contributions reduce the theoretical uncertainty in the extraction of the CKM matrix elements |V_{ub}| and |V_{cb}| from their respective measured inclusive semileptonic branching ratio(s).
Cite
@article{arxiv.hep-ph/0209075,
title = {Pade/renormalization-group improvement of inclusive semileptonic B decay rates},
author = {M. R. Ahmady and F. A. Chishtie and V. Elias and A. H. Fariborz and D. G. C. McKeon and T. N. Sherry and T. G. Steele},
journal= {arXiv preprint arXiv:hep-ph/0209075},
year = {2009}
}
Comments
3 pages, latex using espcrc2.sty. Write-up of talk given at BEACH 2002, UBC, Vancouver