the elementary reaction of kaon exclusive electroproduction on protons has been studied ina broad kinematical range. data for the calculation of the form factor of the kaon have been taken atdifferent values of the invariant center of mass energy w in the range w=1.8, 1.85, 1.98, 2.08 (gev), forone value of the transferred 4-momentum q2=2.35 (gev/c)2. in this analysis, we calculated σl and σt b...

In the following, the term ‘diffractive electroproduction’ or ‘diffractive deep inelastic scattering (DIS)’ is used to characterize those processes in small-x DIS where, in spite of the high virtuality of the exchanged photon, the proton target remains intact or almost intact. Thus, the term is used synonymously with the expression ‘rapidity gap events in DIS’. Historically, the term diffractio...

This paper combines the graph-theoretical ideas behind Moravcsik's theorem with a completely analytic derivation of discrete phase-ambiguities, recently published by Nakayama. The result is new graphical procedure for certain types complete sets observables an amplitude-extraction problem $N$ helicity-amplitudes. applied to pseudoscalar meson photoproduction ($N = 4$ amplitudes) and electroprod...

We investigate the possibility to acquire information on the generalized parton distribution E and, through a model for E, also on the u-quark total angular momentum Ju by studying deeply virtual Compton scattering and hard exclusive ρ electroproduction on a transversely polarized hydrogen target at Hermes. It is found that a change in Ju from zero to 0.4 corresponds to a 4σ (2σ) difference in ...

The neutral pion electroproduction on the proton is considered in the framework phenomenological model based on the PCAC, current algebra with hard pions and chiral symmetry breaking interaction. The swave differential cross-section of the electroproduction of neutral pions off protons near the threshold is predicted as function photon momentum transfer squared k2 . The swave multipoles ReE0+ a...