Amplitude analysis of B+ →j /ψφK+ decays

Abstract

The first full amplitude analysis of B+ → J/ψφK+ with J/ψ → µ +µ −, φ → K+K− decays is performed with a data sample of 3 fb−1 of pp collision data collected at √ 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 φK+, and four J/ψφ 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. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the K∗ (1680)+ → φK+ transition.