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Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/133023
Measurement of the B→Xsℓ+ℓ− Branching Fraction and Search for Direct CP Violation from a Sum of Exclusive Final States
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We measure the total branching fraction of the flavor-changing neutral-current process B → X s ℓ + ℓ − , along with partial branching fractions in bins of dilepton and hadronic system ( X s ) mass, using a sample of 471 × 1 0 6 Υ ( 4 S ) → B ¯ B events recorded with the BABAR detector. The admixture of charged and neutral B mesons produced at PEP-II2 are reconstructed by combining a dilepton pair with 10 different X s final states. Extrapolating from a sum over these exclusive modes, we measure a lepton-flavor-averaged inclusive branching fraction B ( B → X s ℓ + ℓ − ) = [ 6.7 3 + 0.70 − 0.64 ( stat ) + 0.34 − 0.25 ( exp syst ) ± 0.50 ( model syst ) ] × 1 0 − 6 for m 2 ℓ + ℓ − > 0.1 GeV 2 / c 4 . Restricting our analysis exclusively to final states from which a decaying B meson's flavor can be inferred, we additionally report measurements of the direct C P asymmetry A C P in bins of dilepton mass; over the full dilepton mass range, we find A C P = 0.04 ± 0.11 ± 0.01 for a lepton-flavor-averaged sample.
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GRAUGÉS POUS, Eugeni and BABAR Collaboration. Measurement of the B→Xsℓ+ℓ− Branching Fraction and Search for Direct CP Violation from a Sum of Exclusive Final States. Physical Review Letters. 2014. Vol. 112, num. 21, pags. 211802. ISSN 0031-9007. [consulted: 11 of June of 2026]. Available at: https://hdl.handle.net/2445/133023