4 We calculate the exclusive process γ * L (Q 2 1)γ * L (Q 2 2) → ρ 0 L ρ 0 L , at high energy. The Born order estimate and the leading (LLA) and next to leading order (NLLA) BFKL resum-mation effects show the feasibility of experimental detection in a quite large range of Q 2 values at future high energy e + e − linear colliders. 3 present address 4 Unité mixte 8627 du CNRS.

Exclusive coherent and incoherent electroproduction of the p° meson from H and N targets has been studied at the HERMES experiment as a function of coherence length (lc), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared fourmomentum of the virtual photon (—<2). The ratio of N to *H cross sections per nucleon, called nuclear transparency, was found to inc...

The diffractive program of the CDF Collaboration at the Fermilab Tevatron pp̄ Collider is reviewed with emphasis on recent results from Run II at √ s =1.96 TeV. Results are presented on the x-Bjorken and Q dependence of the diffractive structure function obtained from dijet production, on the slope parameter of the t-distribution of diffractive events as a function of Q in the range 1 GeV < Q < ...

We present a perturbative calculation of baryon pair production in two-photon collisions, γγ → BB̄, in which baryons are treated as quark-diquark systems. Our approach accounts for constituent mass effects in a systematic way. Taking the diquark-model parameters from foregoing studies of other electronand photon-induced baryonic reactions, our results agree well with the most recent large moment...

We investigate two exclusive reactions with a Θ + pentaquark in the final state: electro-production of a K meson on the nucleon, and K + scattering on a neutron target producing a lepton pair. These reactions offer unique opportunities to investigate the structure of pentaquark baryons at parton level. We discuss the generalized parton distributions for the N → Θ + transition and give the leadi...

Several new model independent techniques for the analysis of multidimensional data are presented and applied to exclusive multiparticle production. For the reaction pp-+pprr'n+~c-~from 12 to 28 GeV/c, an algorithm that directly compares two multidimensional point distributions is used to show that the shape of d120/d($?)12 is energy independent while d60/dx6 (x=p,,/pmax) varies dramatically wit...

Exclusive production of vector mesons at HERA has attracted a lot of attention in recent years because of the theoretical suggestion that this is a good way to measure the gluon distribution, as simple arguments 1 suggest that the cross section behaves as the square of xg(x). Recently, these arguments have been formalised and extended by Collins, Frankfurt and Strikman in the context of a facto...