Darmstadt 2016 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HK: Fachverband Physik der Hadronen und Kerne
HK 16: Hadron Structure and Spectroscopy III
HK 16.1: Group Report
Tuesday, March 15, 2016, 14:00–14:30, S1/01 A5
Measurement of the Two-Photon Exchange in the Elastic e±p Scattering at the OLYMPUS Experiment at DESY — •Dmitry Khaneft and OLYMPUS Collaboration — Helmholtz-Institut Mainz, Mainz, Deutschland
The OLYMPUS experiment aims to resolve the experimental discrepancy in the determination of the ratio of the proton electric to magnetic form factor, R = GE/GM, extracted using Rosenbluth separation and polarization transfer technique. This discrepancy can be explained by a two-photon exchange contribution in lepton-nucleon scattering. A measurement of the elastic scattering cross section ratio σe+p/σe−p will allow a direct measurement of the two-photon exchange amplitude. The OLYMPUS experiment was carried out at DESY Hamburg, Germany using 2 GeV electron and positron beams in the DORIS storage ring incident on an internal hydrogen gas target. Multiple independent luminosity monitors were operated in parallel to the main spectrometer during data taking to allow for a precise relative luminosity measurement. Approximately 4.45 fb−1 of integrated luminosity were collected. The OLYMPUS experiment and the status of the analysis will be discussed.