Measurement of the B -> X(s)l(+)l(-) branching fraction with a sum over exclusive modes

We measure the branching fraction for the flavor-changing neutral-current process B → X s ℓ + ℓ − with a sample of 89 × 10 6 Υ ( 4 S ) → B ¯¯¯ B events recorded with the BABAR detector at the PEP-II e + e − storage ring. The final state is reconstructed from e + e − or μ + μ − pairs and a hadronic system X s consisting of one K ± or K 0 S and up to two pions, with at most one π 0 . We observe a signal of 40 ± 10 ( s t a t ) ± 2 ( s y s t ) events and extract the inclusive branching fraction B ( B → X s ℓ + ℓ − ) = ( 5.6 ± 1.5 ( s t a t ) ± 0.6 ( e x p     s y s t ) ± 1.1 ( m o d e l     s y s t ) ) × 10 − 6 for m ℓ + ℓ − > 0.2     G e V / c 2 .