The OLYMPUS experiment

OLYMPUS is an experiment mounted by an international collaboration at DESY, Hamburg, Germany to provide a ±1% measurement of the cross section ratio of positron-proton to electron-proton elastic scattering in the range 0.6 < Q2 < 2.2 (GeV/c)2. The goal is to provide a definitive experimental verification of the generally accepted explanation of the discrepancy between cross-section and recoil polarization techniques in determination of the form factor ratio GEp(Q2)/GMp(Q2).