Tumasyan, A.Adam, W.Andrejkovic, J.W.Bergauer, T.Chatterjee, S.Damanakis, K.Dragicevic, M.2025-03-232025-03-2320221434-6044https://doi.org/10.1140/epjc/s10052-022-10315-yhttps://hdl.handle.net/11486/4178Using 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 Bs0→ψ(2S)KS0 and 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(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)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 Bs0 and B mesons, fs/ fd. © 2022, The Author(s).eninfo:eu-repo/semantics/openAccessArticle82510.1140/epjc/s10052-022-10315-y2-s2.0-85131177055Q1