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Measurement of the B -> Xs l+ l- branching fraction with a sum over exclusive modes

The BABAR Collaboration·B. Aubert
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Abstract

We measure the branching fraction for the flavor-changing neutral-current process B -> Xs l+ l- with a sample of 89 x 10^6 Upsilon(4S) -> BBbar events recorded with the BaBar detector at the PEP-II e+e- storage ring. The final state is reconstructed from e+e- or mu+mu- pairs and a hadronic system consisting of one K or K0s and up to two pions, with at most one pi0. We observe a signal of 40 +/- 10(stat) +/- 2(syst) events and extract the inclusive branching fraction B(B -> Xs l+ l-) = (5.6 +/- 1.5(stat) +/- 0.6(exp syst) +/- 1.1(model syst)) x 10^-6 for mll > 0.2 GeV/c^2.

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The BABAR Collaboration, B. Aubert. 2004-08-12. Measurement of the B -> Xs l+ l- branching fraction with a sum over exclusive modes. https://doi.org/10.1103/physrevlett.93.081802

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