V_{us} from hyperon semileptonic decays
High Energy Physics - Phenomenology
2009-11-10 v1
Abstract
A model-independent determination of the CKM matrix element V_{us} from five measured strangeness-changing hyperon semileptonic decays is performed. Flavor SU(3) symmetry breaking effects in the leading vector and axial-vector form factors are analyzed in the framework of the 1/N_c expansion of QCD. A fit to experimental data allows one to extract the value V_{us}=0.2199\pm 0.0026, which is comparable to the one from K_{e3} decays. This reconciliation is achieved through second-order symmetry breaking effects of a few percent in the form factors f_1, which increase their magnitudes over their SU(3) predictions.
Cite
@article{arxiv.hep-ph/0410171,
title = {V_{us} from hyperon semileptonic decays},
author = {Ruben Flores-Mendieta},
journal= {arXiv preprint arXiv:hep-ph/0410171},
year = {2009}
}
Comments
23 pages, Revtex4, 12 tables, no figures