Observation of the Resonant Character of the Z(4430)(-) State

LHCb collaboration

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Resonant structures in B-0 -> psi''pi K--(+) decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3 fb(-1) collected with the LHCb detector. The data cannot be described with K+pi(-) resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)(-) -> psi''pi(-) component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)(-) amplitude with the psi''pi(-) mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin parity is determined unambiguously to be 1(+).
Original languageEnglish
Article number222002
Number of pages9
JournalPhysical Review Letters
Issue number22
Publication statusPublished - 4 Jun 2014
Externally publishedYes



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