Exclusive ρ{variant}0 production in deep inelastic muon-proton scattering

Exclusive ρ{variant}0 production has been measured in 120, 200 and 280 GeV muon-proton interactions at high Q2 (1 GeV2 < Q2 < 25 GeV2) and W (6 GeV < W < 19 GeV). The photoproduction cross section decreases as 1/Q4. A shallow t distribution, typical of a hard scattering process is observed and the ρ{variant}0 is found to be dominantly in the helicity zero spin state. The ρ{variant}0s are mainly produced by transverse photons and s-channel helicity conservation seems to be invalid. The data cannot be described by the vector meson dominance model. These data show that at high Q2 even exclusive ρ{variant}0 muoproduction is a hard scattering process and that the soft hadron-like properties of the photon have disappeared. © 1985

A comparison of proton, antiproton and meson distributions in final states of deep inelastic muon scattering

New results on the forward produced protons and antiprotons in high energy muon-nucleon scattering are presented. Their W2, z and p2T dependences are compared with those of the other charged hadrons. Significant differences are observed which can be related to the flavour content of the target and to a difference between the baryon content of quark and gluon jets. © 1984