Can the CP asymmetries in B → ψ KS and B → ψ KL differ?

Yuval Grossman, Alexander L. Kagan, Zoltan Ligeti

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46 Scopus citations


In the standard model the CP asymmetries in B → ψ KS and B → ψ KL are equal in magnitude and opposite in sign to very good approximation. We compute the order εK corrections to each of these CP asymmetries and find that they give a deviation from sin 2β at the half percent level, which may eventually be measurable. However, the correction to aCp(B → ψ KS) + aCP(B → ψ KL) due to εK is further suppressed. The dominant corrections to this sum, at the few times 10-3 level, come from the B lifetime difference, and CP violation in B-B̄ mixing and B → ψ K decay. New physics could induce a significant difference in the sin(δmB t) time dependence in the asymmetries if and only if the "wrong-flavor" amplitudes B → ψ K̄ or B̄ → ψ K are generated. A scale of new physics that lies well below the weak scale would be required. Potential scenarios are therefore highly constrained, and do not appear feasible. A direct test is proposed to set bounds on such effects.

Original languageEnglish
Pages (from-to)327-334
Number of pages8
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number3-4
StatePublished - 4 Jul 2002
Externally publishedYes

Bibliographical note

Funding Information:
It is a pleasure to thank Gerhard Buchalla, Uli Nierste, Soeren Prell, Marie-Helene Schune, Vivek Sharma, João Silva, and Zack Sullivan for helpful discussions. We thank the CERN and SLAC theory groups for hospitality while portions of this work were done. Y.G. was supported in part by the Israel Science Foundation under Grant No. 237/01-1. A.K. was supported in part by the Department of Energy under Grant DE-FG02-84ER40153. Z.L. was supported in part by the Director, Office of Science, Office of High Energy and Nuclear Physics, Division of High Energy Physics, of the US Department of Energy under Contract DE-AC03-76SF00098. The work of Y.G. and Z.L. was also supported in part by the United States–Israel Binational Science Foundation (BSF) through Grant No. 2000133.


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