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The decay B-0s→ ψ(2S)K+π-is observed using a data set corresponding to an integrated luminosity of 3.0fb-1collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV. The branching fraction relative to the B0→ ψ(2S)K+π-decay mode is measured to be, where fs/fd indicates the uncertainty due to the ratio of probabilities for a b quark to hadronise into a B0sor B0meson. Using an amplitude analysis, the fraction of decays proceeding via an intermediate K*(892)0meson is measured to be 0.645±0.049(stat)±0.049(syst) and its longitudinal polarisation fraction is 0.524±0.056(stat)±0.029(syst). The relative branching fraction for this component is determined to be. In addition, the mass splitting between the B0sand B0mesons is measured as M(B0s)-M(B0)=87.45±0.44(stat)±0.09(syst)MeV/c2.
Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., … Zhong, L. (2015). Observation of the decay B-0s→ ψ(2S)K+π-. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 747, 484–494. https://doi.org/10.1016/j.physletb.2015.06.038