Model-Independent Observation of Exotic Contributions to B⁰→J/ψK⁺π⁻ Decays

An angular analysis of B⁰→J/ψK⁺π⁻ decays is performed, using proton-proton collision data corresponding to an integrated luminosity of 3 fb⁻¹ collected with the LHCb detector. The m(K⁺π⁻) spectrum is divided into fine bins. In each m(K⁺π⁻) bin, the hypothesis that the three-dimensional angular distribution can be described by structures induced only by K* resonances is examined, making minimal assumptions about the K⁺π⁻ system. The data reject the K*-only hypothesis with a large significance, implying the observation of exotic contributions in a model-independent fashion. Inspection of the m(J/ψπ⁻) vs m(K⁺π⁻) plane suggests structures near m(J/ψπ⁻) = 4200 and 4600 MeV.