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Title: Leading Order Corrections to the Bethe-Heitler Process in the $$\gamma p\rightarrow l^+l^-p$$ Reaction

Abstract

The ratio of di-lepton production cross sections on a proton, using the $$\gamma p\rightarrow l^+ l^- p$$ process, above and below di-muon production threshold allows to extract the effective lepton-proton interaction, which is required to be identical for electrons and muons if lepton universality is exact. To test for a scenario of broken universality at the percent level, of the size which could explain the different proton charge radii extracted from electron scattering and from muonic hydrogen spectroscopy, we evaluate all one-loop QED corrections to this process, including the full lepton mass dependencies. We furthermore show that two-photon exchange processes with both photons attached to the proton line vanish after averaging over di-lepton angles, and estimate the relatively small radiation off the proton. We compare the full one-loop calculation with a soft-photon approximation of the same order, and present estimates for a planned experiment.

Authors:
 [1];  [2];  [1];  [3]
  1. U. Mainz, PRISMA
  2. Fermilab
  3. Memorial U., Newfoundland
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1546018
Report Number(s):
arXiv:1906.02706; FERMILAB-PUB-19-278-T
1738737
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
TBD
Additional Journal Information:
Journal Name: TBD
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Heller, Matthias, Tomalak, Oleksandr, Vanderhaeghen, Marc, and Wu, Shihao. Leading Order Corrections to the Bethe-Heitler Process in the $\gamma p\rightarrow l^+l^-p$ Reaction. United States: N. p., 2019. Web.
Heller, Matthias, Tomalak, Oleksandr, Vanderhaeghen, Marc, & Wu, Shihao. Leading Order Corrections to the Bethe-Heitler Process in the $\gamma p\rightarrow l^+l^-p$ Reaction. United States.
Heller, Matthias, Tomalak, Oleksandr, Vanderhaeghen, Marc, and Wu, Shihao. Thu . "Leading Order Corrections to the Bethe-Heitler Process in the $\gamma p\rightarrow l^+l^-p$ Reaction". United States. https://www.osti.gov/servlets/purl/1546018.
@article{osti_1546018,
title = {Leading Order Corrections to the Bethe-Heitler Process in the $\gamma p\rightarrow l^+l^-p$ Reaction},
author = {Heller, Matthias and Tomalak, Oleksandr and Vanderhaeghen, Marc and Wu, Shihao},
abstractNote = {The ratio of di-lepton production cross sections on a proton, using the $\gamma p\rightarrow l^+ l^- p$ process, above and below di-muon production threshold allows to extract the effective lepton-proton interaction, which is required to be identical for electrons and muons if lepton universality is exact. To test for a scenario of broken universality at the percent level, of the size which could explain the different proton charge radii extracted from electron scattering and from muonic hydrogen spectroscopy, we evaluate all one-loop QED corrections to this process, including the full lepton mass dependencies. We furthermore show that two-photon exchange processes with both photons attached to the proton line vanish after averaging over di-lepton angles, and estimate the relatively small radiation off the proton. We compare the full one-loop calculation with a soft-photon approximation of the same order, and present estimates for a planned experiment.},
doi = {},
journal = {TBD},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {6}
}