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Study of B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- Decays: Measurement of the Ratio of Branching Fractions and Search for Direct CP Violation

The BABAR Collaboration·B. Aubert
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Abstract

We study B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays in a sample of about 89 million BB~ pairs collected with the BABAR detector at the PEP-II asymmetric B-factory at SLAC. We observe a signal of 244 +/- 20 B^+/- --> J/psi pi^+/- events and determine the ratio BF(B^+/- --> J/psi pi^+/-)/BF(B^+/- --> J/psi K^+/-) to be [5.37 +/- 0.45 (stat.) +/- 0.11 (syst)]%. The charge asymmetries for the B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- decays are determined to be A_pi = 0.123 +/- 0.085 (stat.) +/- 0.004 (syst.) and A_K = 0.030 +/- 0.015 (stat.) +/- 0.006 (syst.), respectively.

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The BABAR Collaboration, B. Aubert. 2004-01-23. Study of B^+/- --> J/psi pi^+/- and B^+/- --> J/psi K^+/- Decays: Measurement of the Ratio of Branching Fractions and Search for Direct CP Violation. https://doi.org/10.1103/physrevlett.92.241802

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