Bonn 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Bonn musste abgesagt werden! Lesen Sie mehr ...
HK 2.4: Vortrag
Montag, 30. März 2020, 17:30–17:45, J-HS A
New study of the two-photon exchange amplitude from polarized electron scattering — D. Balaguer Ríos1, S. Baunack1,3, L. Capozza1, J. Diefenbach1,2, B. Gläser1,2, •B. Gou2, Y. Imai1,2, E.-M. Kabuss1, J.H. Lee1, F. Maas1,2,3, M. C. Mora Espí1,2, E. Schilling1, D. von Harrach1, and C. Weinrich1 for the A4 collaboration — 1Institut für Kernphysik, Johannes Gutenberg-Universität Mainz — 2Helmholtz-Institut Mainz — 3PRISMA Cluster of Excellence, Johannes Gutenberg-Universität Mainz
The study of the two-photon exchange amplitude in lepton scattering has drawn significant interest in the past two decades. This is due to the discrepancy between the Rosenbluth separation and polarization transfer data on the proton form factor ratio. In order to extract hadron structure information correctly in electron nucleon scattering, one needs to understand how two-photon exchange may affect various observables. The transverse single spin asymmetry, which arises from the interference of the one- and two-photon exchange amplitude, provides an excellent testing ground for the two-photon exchange mechanism. The A4 collaboration at the MAMI accelerator in Mainz has performed measurements of the transverse beam spin asymmetry at various beam energies between 300 MeV and 1.5 GeV. Results of a recent analysis will be presented in this talk.