Evidence for X(3872)→ψ(2S)γ in B±→X(3872)K± Decays and a Study of B→c¯cγK

Abstract

In a search for B → c ¯ c γ K decays with the BABAR detector, where c ¯ c includes J / ψ and ψ ( 2 S ) , and K includes K ± , K 0 S , and K ∗ ( 892 ) , we find evidence for X ( 3872 ) → J / ψ γ and X ( 3872 ) → ψ ( 2 S ) γ with 3.6 σ and 3.5 σ significance, respectively. We measure the product of branching fractions B ( B ± → X ( 3872 ) K ± ) × B ( X ( 3872 ) → J / ψ γ ) = [ 2.8 ± 0.8 ( stat ) ± 0.1 ( syst ) ] × 10 − 6 and B ( B ± → X ( 3872 ) K ± ) × B ( X ( 3872 ) → ψ ( 2 S ) γ ) = [ 9.5 ± 2.7 ( stat ) ± 0.6 ( syst ) ] × 10 − 6 .