PT Journal AU LHCb Collaboration (Aaij, Rea Martinez-Vidal, F Oyanguren, A Remon Alepuz, C Ruiz Valls, P Sanchez Mayordomo, C TI Observation of J/psi phi Structures Consistent with Exotic States from Amplitude Analysis of B+ -> J/psi phi K+ Decays SO Physical Review Letters JI Phys. Rev. Lett. PY 2017 BP 022003 EP 10pp VL 118 IS 2 DI 10.1103/PhysRevLett.118.022003 LA English AB The first full amplitude analysis of B+ -> J/psi phi K+ with J/psi -> mu(+)mu(-), phi -> K+K- decays is performed with a data sample of 3 fb(-1) of pp collision data collected at root s = 7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into phi K+ , and four J/psi phi structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state. ER