Resonant structures in B0→ψ′π−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+π− resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)−→ψ′π− component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)− amplitude with the ψ′π− 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+.
Observation of the resonant character of the Z(4430)− state
ANDREOTTI, Mirco;BALDINI, Wander;BOZZI, Concezio;CALABRESE, Roberto;CORVO, Marco;FIORE, Marco;FIORINI, Massimiliano;LUPPI, Eleonora;MANZALI, Matteo;SAVRIE', Mauro;TELLARINI, Giulia;TOMASSETTI, Luca;
2014
Abstract
Resonant structures in B0→ψ′π−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+π− resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)−→ψ′π− component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)− amplitude with the ψ′π− 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+.File in questo prodotto:
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