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.