U-Spin Tests of the Standard Model and New Physics
Abstract
Within the standard model, a relation involving branching ratios and direct CP asymmetries holds for the B-decay pairs that are related by U-spin. The violation of this relation indicates new physics (NP). In this paper, we assume that the NP affects only the Delta S = 1 decays, and show that the NP operators are generally the same as those appearing in B -> pi K decays. The fit to the latest B -> pi K data shows that only one NP operator is sizeable. As a consequence, the relation is expected to be violated for only one decay pair: Bd -> K0 pi0 and Bs -> Kbar0 pi0.
Cite
@article{arxiv.hep-ph/0701199,
title = {U-Spin Tests of the Standard Model and New Physics},
author = {Makiko Nagashima and Alejandro Szynkman and David London},
journal= {arXiv preprint arXiv:hep-ph/0701199},
year = {2008}
}
Comments
12 pages, latex, no figures. References changed to follow MPL guidelines; info added about U-spin breaking and small NP strong phases; discussion added about final-state pi-K rescattering; analysis and conclusions unaltered