Abstract:
Using a data sample of s√=13TeVs=13TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103~fb−1103~fb−1, the B0s→ψ(2S)K0SBs0→ψ(2S)KS0 and B0→ψ(2S)K0Sπ+π−B0→ψ(2S)KS0π+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))×10−2B(Bs0→ψ(2S)KS0)/B(B0→ψ(2S)KS0)=(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)B(B0→ψ(2S)KS0π+π−)/B(B0→ψ(2S)KS0)=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 B0sBs0 and B0B0 mesons, fs/fdfs/fd.