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

An angular analysis of B0 → J/ψ K+ 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/ψ π−) vs m(K+ π−) plane suggests structures near m(J/ψ π−) = 4200 and 4600 MeV.