The OLYMPUS experiment
- Milner, R.
- Hasell, D. K.
- Beck, R.
- Belostotski, S.
- Bernauer, J. C.
- Bessuille, J.
- Brinker, F.
- Buck, B.
- Calarco, J. R.
- Carassiti, V.
- Cisbani, E.
- Ciullo, G.
- Kohl, M.
- Contalbrigo, M.
- D'Ascenzo, N.
- De Leo, R.
- Diefenbach, J.
- Donnelly, T. W.
- Dow, K.
- Elbakian, G.
- Eversheim, D.
- Frullani, S.
- Funke, Ch.
- Schneekloth, U.
- Gavrilov, G.
- Gläser, B.
- Görrissen, N.
- Hauschildt, J.
- Henderson, B. S.
- Hoffmeister, Ph.
- Holler, Y.
- Ice, L. D.
- Izotov, A.
- Kaiser, R.
- Akopov, N.
- Karyan, G.
- Kelsey, J.
- Khaneft, D.
- Klassen, P.
- Kiselev, A.
- Krivshich, A.
- Lehmann, I.
- Lenisa, P.
- Lenz, D.
- Lumsden, S.
- Alarcon, R.
- Ma, Y.
- Maas, F.
- Marukyan, H.
- Miklukho, O.
- Movsisyan, A.
- Murray, M.
- Naryshkin, Y.
- O'Connor, C.
- Perez Benito, R.
- Perrino, R.
- Andreev, V. A.
- Redwine, R. P.
- Rodríguez Piñeiro, D.
- Rosner, G.
- Russell, R. L.
- Schmidt, A.
- Seitz, B.
- Statera, M.
- Thiel, A.
- Vardanyan, H.
- Veretennikov, D.
- Ates, O.
- Vidal, C.
- Winnebeck, A.
- Yeganov, V.
- OLYMPUS Collaboration
- Avetisyan, A.
- Bayadilov, D.
DOIAbstract
The OLYMPUS experiment was designed to measure the ratio between the positron-proton and electron-proton elastic scattering cross sections, with the goal of determining the contribution of two-photon exchange to the elastic cross section. Two-photon exchange might resolve the discrepancy between measurements of the proton form factor ratio, $\mu_p G^p_E/G^p_M$, made using polarization techniques and those made in unpolarized experiments. OLYMPUS operated on the DORIS storage ring at DESY, alternating between 2.01~GeV electron and positron beams incident on an internal hydrogen gas target. The experiment used a toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight detectors to measure rates for elastic scattering...