Observation of the resonant character of the Z (4430)- state

The LHCb Collaboration

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Resonant structures in B0 -K+ decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3fb-1 collected with the LHCb detector. The data cannot be described with K+Ï€- resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)- φπ- component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)- amplitude with the Ïâ€Ï€- 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 - 2014
Externally publishedYes

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