Observation of New Charmonium or Charmoniumlike States in B^{+}→D^{*±}D^{∓}K^{+} Decays

A study of resonant structures in B^{+}→D^{+}D^{-}K^{+} and B^{+}→D^{-}D^{+}K^{+} decays is performed, using proton-proton collision data at center-of-mass energies of sqrt[s]=7, 8, and 13 TeV recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb^{-1}. A simultaneous amplitude fit is performed to the two channels with contributions from resonances decaying to D^{-}D^{+} and D^{+}D^{-} states linked by C parity. This procedure allows the C parities of …