Reanalysis of the Four-Quark Operators Relevant to \Lambda_b Lifetime from QCD Sum Rule
High Energy Physics - Phenomenology
2009-10-31 v2
Abstract
\Lambda_b matrix element of four-quark operator relevant to its lifetime is reanalyzed by QCD sum rule. The new ingredients introduced are that (1) more vacuum condensates are considered; (2) different quark-hadron duality is adopted; and (3) the possible deviation from the vacuum saturation assumption for the four quark condensates is considered. With \kappa_1=4 the related hadronic parameter r is calculated to be 3.6 \pm 0.9, and the lifetime ratio \tau(\Lambda_b)/\tau(B^0) = 0.83 \pm 0.04, which is consistent with the experimental data.
Keywords
Cite
@article{arxiv.hep-ph/9906300,
title = {Reanalysis of the Four-Quark Operators Relevant to \Lambda_b Lifetime from QCD Sum Rule},
author = {Chao-Shang Huang and Chun Liu and Shi-Lin Zhu},
journal= {arXiv preprint arXiv:hep-ph/9906300},
year = {2009}
}
Comments
12 pages, revtex, one figure, more discussions and references added