Observation of B0 → ψ(2S)K0 Sπ + π− and B0 s → ψ(2S)K0 S decays

Abstract

Using a data sample of 𝑠√=13TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103fb−1, the B0s→ψ(2S)K0S and B0→ψ(2S)K0Sπ+π− decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to ℬ(B0s→ψ(2S)𝐾0S)/ℬ(B0→ψ(2S)𝐾0S)=(3.33±0.69(stat)±0.11(syst)±0.34(𝑓s/𝑓d))×10−2 and ℬ(B0→ψ(2S)K0Sπ+π−)/ℬ(B0→ψ(2S)K0S)=0.480±0.013(stat)±0.032(syst), where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B0s and B0 mesons, 𝑓s/𝑓d.