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Title: The two-photon exchange experiment at DESY
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$$2.12\times 10^{35}$$2.12×1035 cm$$^{-2}\cdot $$-2·s$$^{-1}$$-1 ($$\approx 200$$200times the luminosity achieved by OLYMPUS). The proposed two-photon exchange experiment (TPEX) entails a commissioning run at a beam energy of 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to$$Q^2=4.6$$Q2=4.6 (GeV/c)$$^2$$2(twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.

 
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Award ID(s):
2110229
NSF-PAR ID:
10499171
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publisher / Repository:
Springer Science + Business Media
Date Published:
Journal Name:
The European Physical Journal A
Volume:
60
Issue:
4
ISSN:
1434-601X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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