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(+).
Archilli, F., Carboni, G., Santovetti, E., The LHCb, C. (2014). Observation of the Resonant Character of the Z(4430)(-) State. PHYSICAL REVIEW LETTERS, 112(22) [10.1103/PhysRevLett.112.222002].
Observation of the Resonant Character of the Z(4430)(-) State
Archilli, FMembro del Collaboration Group
;Carboni, GMembro del Collaboration Group
;Santovetti, EMembro del Collaboration Group
;
2014-01-01
Abstract
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(+).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
