Exclusive $$\rho ^0$$ ρ 0 meson photoproduction with a leading neutron at HERA

A New Measurement of Exclusive Ρ @bullet Photoproduction at Hera

Exclusive ρ • photoproduction has been measured with high statistics by the H1 Collaboration. The kinematical range is 20 < W < 90 GeV, |t| < 3 GeV 2 and Q 2 < 4 GeV 2. Cross sections are measured differentially in W and t and allow the extraction of the Pomeron trajectory, for the first time using ρ • photoproduction data of one single experiment. The preliminary result, α P (t) = 1.093 ± 0.00...

Subthreshold Ρ 0 Photoproduction

Exclusive Photoproduction at HERA

The exclusive Υ photoproduction, γ p → Υp, has been studied with the ZEUS experiment in ep collisions at HERA using an integrated luminosity of 468 pb−1. The measurement covers the kinematic range 60 < W < 220 GeV and Q2 < 1 GeV2, where W is the photon-proton centre-ofmass energy and Q2 is the photon virtuality. These results, which represent the analysis of the full ZEUS data sample for this c...

Elastic ρ meson production at HERA

Results on elastic electroproduction of ρ mesons are presented for a photon virtuality in the range 1 < Q < 60 GeV and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the (ππ) mass distribution is discussed and measurements of the cross section dependences on Q, W and t (the four-momentum transfer squared to the proton) are presented. The full set of ̺ spin densi...

New Results in ρ 0 Meson Physics

We compare the predictions of a range of existing models based on the Vector Meson Dominance hypothesis with data on e+e− → π+π− and e+e− → μ+μ− Permanent address. Present address. cross-sections and the phase and near-threshold behavior of the timelike pion form factor, with the aim of determining which (if any) of these models is capable of providing an accurate representation of the full ran...