# Observation of the decay B¯¯¯0s→ψ(2S)K+π−

Abstract : The decay B¯¯¯0s→ψ(2S)K+π− is observed using a data set corresponding to an integrated luminosity of 3.0fb−1 collected 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 B(B¯¯¯0s→ψ(2S)K+π−)B(B0→ψ(2S)K+π−)=5.38±0.36(stat)±0.22(syst)±0.31(fs/fd)%, where fs/fd indicates the uncertainty due to the ratio of probabilities for a b quark to hadronise into a B0s or B0 meson. Using an amplitude analysis, the fraction of decays proceeding via an intermediate K∗(892)0 meson 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 B(B¯¯¯0s→ψ(2S)K∗(892)0)B(B0→ψ(2S)K∗(892)0)=5.58±0.57(stat)±0.40(syst)±0.32(fs/fd)%. In addition, the mass splitting between the B0s and B0 mesons is measured as M(B0s)−M(B0)=87.45±0.44(stat)±0.07(syst)MeV/c2.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-01135717
Contributor : Sabine Starita <>
Submitted on : Wednesday, March 25, 2015 - 5:25:25 PM
Last modification on : Tuesday, April 20, 2021 - 12:00:14 PM

### Citation

R. Aaij, Y. Amhis, S. Barsuk, M. Borsato, O. Kochebina, et al.. Observation of the decay B¯¯¯0s→ψ(2S)K+π−. Physics Letters B, Elsevier, 2015, 747, pp.484-494. ⟨10.1016/j.physletb.2015.06.038⟩. ⟨in2p3-01135717⟩

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