https://doi.org/10.1140/epja/s10050-021-00474-z
Regular Article - Experimental Physics
Beam charge asymmetries for deeply virtual Compton scattering off the proton
1
Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405, Orsay, France
2
Thomas Jefferson National Accelerator Facility, 23606, Newport News, VA, USA
3
University of Connecticut, CT U-3046, Storrs, USA
4
Florida International University, 33199, Miami, FL, USA
5
Lamar University, 77710, Beaumont, TX, USA
6
Università degli Studi di Brescia, 25121, Brescia, Italy
7
University of Virginia, 22904, Charlottesville, VA, USA
8
Duke University, 27708, Durham, NC, USA
9
Michigan State University, 48824, East Lansing, MI, USA
10
Università di Ferrara, 44121, Ferrara, Italy
11
INFN, Sezione di Ferrara, 44122, Ferrara, Italy
12
INFN, Sezione di Genova, 16100, Genova, Italy
13
Universität Gießen, 35390, Gießen, Germany
14
IRFU, CEA, Université Paris-Saclay, 91191, Gif-sur-Yvette, France
15
University of Glasgow, G12 8QQ, Glasgow, United Kingdom
16
Mississippi State University, Mississippi State, 39762, Starkville, MS, USA
17
Old Dominion University, 23529, Norfolk, VA, USA
18
INFN, Sezione di Pavia, 27100, Pavia, Italy
19
University of West Florida, 32514, Pensacola, FL, USA
20
Idaho State University, 83209, Pocatello, ID, USA
21
Center for Frontiers in Nuclear Science, Stony Brook University, 11794, Stony Brook, NY, USA
22
INFN, Sezione di Torino, 10125, Torino, Italy
23
Riken BNL Research Center, 11973, Upton, NY, USA
24
The George Washington University, 20052, Washington, DC, USA
Received:
9
March
2021
Accepted:
25
April
2021
Published online:
8
June
2021
The unpolarized and polarized Beam Charge Asymmetries (BCAs) of the 
process off unpolarized hydrogen are discussed. The measurement of BCAs with the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility, using polarized positron and electron beams at 10.6 GeV is investigated. This experimental configuration allows to measure azimuthal and t-dependences of the unpolarized and polarized BCAs over a large 
phase space, providing a direct access to the real part of the Compton Form Factor (CFF) 
. Additionally, these measurements confront the Bethe-Heitler dominance hypothesis and eventual effects beyond leading twist. The impact of potential positron beam data on the determination of CFFs is also investigated within a local fitting approach of experimental observables. Positron data are shown to strongly reduce correlations between CFFs and consequently improve significantly the determination of 
.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
