# Model-Independent Observation of Exotic Contributions to ${B}^{0}\to J/\psi {K}^{+}{\pi }^{-}$ Decays

18 April 2019

Abstract: An angular analysis of ${B}^{0}\to J/\psi {K}^{+}{\pi }^{-}$ decays is performed, using proton-proton collision data corresponding to an integrated luminosity of $3\text{}\text{}{\mathrm{fb}}^{-1}$ collected with the LHCb detector. The $m\left({K}^{+}{\pi }^{-}\right)$ spectrum is divided into fine bins. In each $m\left({K}^{+}{\pi }^{-}\right)$ 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 ${K}^{+}{\pi }^{-}$ 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 $m\left(J/\psi {\pi }^{-}\right)$ vs $m\left({K}^{+}{\pi }^{-}\right)$ plane suggests structures near $m\left(J/\psi {\pi }^{-}\right)=4200$ and 4600 MeV.

Published in: Physical Review Letters 122 (2019)