The two-photon exchange experiment at DESY
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Published:2024-04-05
Issue:4
Volume:60
Page:
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ISSN:1434-601X
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Container-title:The European Physical Journal A
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language:en
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Short-container-title:Eur. Phys. J. A
Author:
Alarcon R., Beck R., Bernauer J. C., Broering M., Christopher A., Cline E. W., Dhital S., Dongwi B., Fernando I., Finger M., Finger M., Friščić I., Gautam T., Grauvogel G. N., Hasell D. K., Hen O., Horn T., Ihloff E., Johnston R., Kelsey J., Kohl M., Kutz T., Lavrukhin I.ORCID, Lee S., Lorenzon W., Lunkenheimer S., Maas F., Milner R. G., Moran P., Nazeer J., Patel T., Rathnayake M., Raymond R., Redwine R. P., Schmidt A., Schneekloth U., Sokhan D., Suresh M., Vidal C., Yang Z.
Abstract
AbstractWe 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
×
10
35
cm$$^{-2}\cdot $$
-
2
·
s$$^{-1}$$
-
1
($$\approx 200$$
≈
200
times 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 $$Q^2=4.6$$
Q
2
=
4.6
(GeV/c)$$^2$$
2
(twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.
Funder
PIER Hamburg-MIT/BOS Seed Project MEYS of Czech Republic National Science Foundation U.S. Department of Energy
Publisher
Springer Science and Business Media LLC
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