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arXiv · hep-ph/9803368

Direct CP Violation in B -> X_s gamma Decays as a Signature of New Physics

A. L. Kagan·M. Neubert
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Abstract

We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in magnitude. In extensions of the Standard Model with new CP-violating couplings, large CP asymmetries are possible without conflicting with the experimental value of the branching ratio for the decays B -> X_s gamma. In particular, large asymmetries arise naturally in models with enhanced chromo-magnetic dipole operators. 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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A. L. Kagan, M. Neubert. 1998-05-15. Direct CP Violation in B -> X_s gamma Decays as a Signature of New Physics. https://doi.org/10.1103/physrevd.58.094012

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