Apr 26 – 30, 2009
Palacio de Congresos de Madrid
Europe/Zurich timezone

Measurement of J/psi helicity distributions in inelastic photoproduction at ZEUS

Apr 27, 2009, 11:40 AM
Room "SALA 2-B" (Palacio de Congresos de Madrid)

Room "SALA 2-B"

Palacio de Congresos de Madrid

Paseo de la Castellana, 99 28046 Madrid España


Alessandro Bertolin (Padova)


The decay angular distributions for inelastic photoproduction of J/psi mesons have been measured with the ZEUS detector at HERA, using an integrated luminosity of 468 pb-1. J/psi mesons were identified using their decays into muons. The polar and azimuthal distributions of the mu+ in the J/psi rest frame have been measured as a function of pT and as function of z, where pT is the transverse momentum of the J/psi in the laboratory frame and z is the the fraction of the incident photon energy carried by the J/psi in the proton rest frame. The experimental results were compared to the theoretical predictions at leading and next-to-leading order.

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