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Looking for the Unexpected: Direct CP Violation in B -> X_s gamma Decays

Matthias Neubert
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Abstract

The observation of a sizable direct CP asymmetry in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, this asymmetry is below 1% in magnitude. In extensions of the Standard Model with new CP-violating couplings, large asymmetries are possible without conflicting with the experimental value of the B -> X_s gamma branching ratio. In particular, large asymmetries arise naturally in models with enhanced chromo-magnetic dipole transitions. Some generic examples of such models are explored and their implications for the semileptonic branching ratio and charm yield in B decays discussed.

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Matthias Neubert. 1998-05-31. Looking for the Unexpected: Direct CP Violation in B -> X_s gamma Decays. https://arxiv.org/abs/hep-ph/9806206

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