English

Beam charge asymmetries for deeply virtual Compton scattering off the proton

Nuclear Experiment 2021-06-30 v1 High Energy Physics - Experiment

Abstract

The unpolarized and polarized Beam Char\-ge Asymmetries (BCAs) of the \vve±pe±pγ\vv{e}^{\pm}p \to e^{\pm}p \gamma 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 tt-dependences of the unpolarized and polarized BCAs over a large (xB,Q2)(x_B,Q^2) phase space, providing a direct access to the real part of the Compton Form Factor (CFF) H{\mathcal H}. 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 e[H]\Re {\rm e} [\mathcal{H}].

Keywords

Cite

@article{arxiv.2103.12651,
  title  = {Beam charge asymmetries for deeply virtual Compton scattering off the proton},
  author = {V. Burkert and L. Elouadrhiri and F. -X. Girod and S. Niccolai and E. Voutier and A. Afanasev and L. Barion and M. Battaglieri and J. C. Bernauer and A. Bianconi and R. Capobianco and M. Caudron and L. Causse and P. Chatagnon and T. Chetry and G. Ciullo and P. L. Cole and M. Contalbrigo and G. Costantini and M. Defurne and A. ~Deur and S. Diehl and R. Dupré and M. Ehrhart and I. P. Fernando and A. Filippi and T. Forest and J. Grames and P. Gueye and S. Habet and D. Higinbotham and A. Hobart and C. E. Hyde and K. Joo and A. Kim and V. Klimenko and H. -S. Ko and V. Kubarovsky and M. Leali and P. Lenisa and D. Marchand and V. Mascagna and M. McCaughan and B. McKinnon and A. Movsisyan and C. Muñoz~Camacho and L. Pappalardo and E. Pasyuk and M. Poelker and K. Price and B. Raue and M. Shabestari and R. Santos and V. Sergeyeva and I. Strakovsky and P. Stoler and L. Venturelli and S. Zhao and Z. W. ~Zhao and the CLAS Collaboration},
  journal= {arXiv preprint arXiv:2103.12651},
  year   = {2021}
}

Comments

11 pages, 10 figures, Article part of the EPJA Topical Issue about "Positron beams and physics at Jefferson Lab". arXiv admin note: text overlap with arXiv:2007.15081

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