[en] Generalized Parton Distributions (GPDs) have become a key concept in our studies of hadron structure in QCD. The measurement of suitable experimental observables and the extraction of GPDs from these data is one of the high priority 12 GeV programs at Jefferson Lab. Deeply Virtual Compton Scattering (DVCS) is generally thought of as the most promising channel for probing GPDs in the valence quark region. However, the inverse process, Timelike Compton Scattering (TCS) can provide an important complementary measurement, in particular of the real part of the Compton amplitude and power corrections at intermediate values of Q². The first studies of TCS using real tagged and quasi-real untagged photons were performed in Hall B at Jefferson Lab.

[en] Polarized electrons have been accelerated in the electron stretcher accelerator ELSA for the first time. Up to 2.1 GeV the polarization of the electron beam supplied by the 120 keV polarized electron source has been measured with a Moeller polarimeter. Preliminary results of polarization measurements at high energies and the performance of the source are presented

[en] A major goal of the 12 GeV upgrade at Jefferson Lab is to map out the Generalized Parton Distributions (GPDs) in the valence region. This is primarily done through Deeply Virtual Compton Scattering (DVCS), which provides the simplest and cleanest way of accessing the GPDs. However, the 'inverse' process, Timelike Compton Scattering (TCS), can provide an important complement, in particular for measuring the real part of the amplitude and understanding corrections at finite Q². The first measurements of TCS have recently been carried out in Hall B at Jefferson Lab, using both tagged and untagged photon beams.

[en] Statistically improved data of total cross sections and of angular distributions for differential cross sections and hyperon recoil polarizations of the reactions γp→K⁺Λ and γp→K⁺Σ⁰ have been collected with the SAPHIR detector at photon energies between threshold and 2.0 GeV. Here total cross section data up to 1.5 GeV are presented. The opposite sign of Λ and Σ polarization and the change of sign between forward and backward direction could be confirmed by higher statistics. A steep threshold behaviour of the K⁺Λ total cross section is observed