First observation of Bs⁰→J/Ψf0(980) decays

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay B _s ⁰→J/Ψf0(980) is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the B _s ⁰ system. Using a fit to the Π ⁺Π ^- mass spectrum with interfering resonances gives Rf0/Φ≡Γ(Bs0→J/Ψf0,f0→Π ⁺Π ^-)Γ(B _s ⁰→J/Ψφ,φ →K ⁺K ^-)=0.252 _-0.032-0.033 ⁺0.046+0.027. In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find R' ≡ Γ(Bs0→J/Ψf0,f0→Π ⁺Π ^-)-980 Mev < 90 Mev)/Γ(B _s ⁰→J/Ψφ,φ→K ⁺K ^-)=0.162±0.022±0.016, where in both cases the uncertainties are statistical and systematic, respectively.