English

The Two-Photon Exchange Experiment at DESY

Nuclear Experiment 2023-07-26 v1

Abstract

We propose a new measurement of the ratio of positron-proton to electron-proton elastic scattering at DESY. The purpose is to determine the contributions beyond single-photon exchange, which are essential for the Quantum Electrodynamic (QED) description of the most fundamental process in hadronic physics. By utilizing a 20 cm long liquid hydrogen target in conjunction with the extracted beam from the DESY synchrotron, we can achieve an average luminosity of 2.12×10352.12\times10^{35} cm2^{-2}\cdots1^{-1}\cdotsr1^{-1} (200\approx200 times the luminosity achieved by OLYMPUS). The proposed TPEX experiment entails a commissioning run at 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to Q2=4.6Q^2=4.6 (GeV/cc)2^2 (twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.

Keywords

Cite

@article{arxiv.2307.13330,
  title  = {The Two-Photon Exchange Experiment at DESY},
  author = {R. Alarcon and R. Beck and J. C. Bernauer and M. Broering and A. Christopher and E. W. Cline and S. Dhital and B. Dongwi and I. Fernando and M. Finger and M. Finger and I. Friščić and T. Gautam and G. N. Grauvogel and D. K. Hasell and O. Hen and T. Horn and E. Ihloff and R. Johnston and J. Kelsey and M. Kohl and T. Kutz and I. Lavrukhin and S. Lee and W. Lorenzon and S. Lunkenheimer and F. Maas and R. G. Milner and P. Moran and J. Nazeer and T. Patel and M. Rathnayake and R. Raymond and R. P. Redwine and A. Schmidt and U. Schneekloth and D. Sokhan and M. Suresh and C. Vidal and Z. Yang},
  journal= {arXiv preprint arXiv:2307.13330},
  year   = {2023}
}

Comments

10 pages, 14 figures. arXiv admin note: substantial text overlap with arXiv:2301.04708

R2 v1 2026-06-28T11:39:26.369Z