Evidence for B+→hcK+ and observation of ηc(2S)→pp¯π+π−
A search for the decays Bþ → hcKþ and B0 → hcK0 S is performed. Evidence for the decay Bþ → hcKþ is found; its significance is 4.8σ. No evidence is found for B0 → hcK0 S. The branching fraction for Bþ → hcKþ is measured to be ð3.7þ1.0 −0.9 þ0.8 −0.8 Þ × 10−5; the upper limit for the B0 → hcK0 S branching fraction is 1.4 × 10−5 at 90% C.L. In addition, a study of the pp¯ πþπ− invariant mass distribution in the channel Bþ → ðpp¯ πþπ−ÞKþ results in the first observation of the decay ηcð2SÞ → pp¯ πþπ− with 12.1σ significance. The analysis is based on the 711 fb−1 data sample collected by the Belle detector at the asymmetric-energy eþe− collider KEKB at the ϒð4SÞ resonance.
Physical Review D
Digital Object Identifier (DOI)
Collaboration, The Belle and Kulasiri, Luminda, "Evidence for
and observation of
ηc(2S)→pp¯π+π−" (2019). Faculty Publications. 4495.