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Related papers: GPDs and DVCS with Positrons

200 papers

We report the first observation of azimuthal beam-spin asymmetries in hard electroproduction of real photons off nuclei. Attributed to the interference between the Bethe-Heitler process and the deeply-virtual Compton scattering process, the…

High Energy Physics - Experiment · Physics 2019-08-14 F. Ellinghaus , R. Shanidze , J. Volmer

The feasibility of extracting generalized parton distributions (GPDs) from deeply-virtual Compton scattering (DVCS) data has recently been questioned because of the existence of an infinite set of so-called ''shadow GPDs'' (SGPDs). These…

High Energy Physics - Phenomenology · Physics 2023-03-24 Eric Moffat , Adam Freese , Ian Cloët , Thomas Donohoe , Leonard Gamberg , Wally Melnitchouk , Andreas Metz , Alexei Prokudin , Nobuo Sato

We overview the construction of Nonforward Parton Distributions (NPD) in Deeply Virtual Compton Scattering (DVCS). Then we turn to the analysis of similar constructs in the weak sector (electroweak NPD's). We argue in favour of a possible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Claudio Coriano` , G. Chirilli , Marco Guzzi

Timelike Compton scattering (TCS) i.e. the exclusive photoproduction of a lepton pair with large invariant mass nicely complements the already successful experimental study of deeply virtual Compton scattering (DVCS). The same Generalized…

High Energy Physics - Phenomenology · Physics 2012-07-12 B. Pire , L. Szymanowski , J. Wagner

We study deeply virtual Compton scattering on a virtual pion that is emitted by a proton. Using a range of models for the generalized parton distributions of the pion, we evaluate the cross section, as well as the beam spin and beam charge…

High Energy Physics - Phenomenology · Physics 2008-12-18 Daniela Amrath , Markus Diehl , Jean-Philippe Lansberg

New results on the Deeply Virtual Compton Scattering process $\gamma^* p \to \gamma p$ (DVCS) from H1 experiment at the $e p$ collider HERA are presented, using data collected during the year 2004 and corresponding to an integrated…

High Energy Physics - Experiment · Physics 2017-08-23 Benoit Roland

We present the recent data issued from the Halls A and B of Jefferson Laboratory for the Deep Virtual Compton Scattering Process on the proton. An important set of data for beam spin asymmetries, unpolarized cross sections and differences…

High Energy Physics - Phenomenology · Physics 2008-12-18 M. Guidal

We review various applications of dispersion relations (DRs) to the electromagnetic structure of hadrons. We discuss the way DRs allow one to extract information on hadron structure constants by connecting information from complementary…

High Energy Physics - Phenomenology · Physics 2018-07-04 B. Pasquini , M. Vanderhaeghen

This study presents the impact of future measurements of deeply virtual Compton scattering (DVCS) with the ePIC detector at the electron-ion collider (EIC), currently under construction at Brookhaven National Laboratory. The considered…

Standard parton distribution functions contain neither information on the correlations between partons nor on their transverse motion, then a vital knowledge about the three dimensional structure of the nucleon is lost. Hard exclusive…

High Energy Physics - Phenomenology · Physics 2008-06-17 Laurent Schoeffel

We present a detailed next-to-leading order (NLO) leading twist QCD analysis of deeply virtual Compton scattering (DVCS) observables, for several different input scenarios, in the MS-bar scheme. We discuss the size of the NLO effects and…

High Energy Physics - Phenomenology · Physics 2011-09-13 Andreas Freund , Martin McDermott

Charge asymmetry in electron (positron) scattering arises from the interference of the Born amplitude and the box-type amplitude corresponding to two virtual photons exchange. It can be extracted from electron proton and positron proton…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. A. Kuraev , V. V. Bytev

The measurement of nuclear generalized parton distributions (GPDs) in hard exclusive processes, such as deeply virtual Compton Scattering (DVCS), will be one of the main achievements of a new generation of experiments at high luminosity,…

Nuclear Theory · Physics 2021-02-03 Sara Fucini , Matteo Rinaldi , Sergio Scopetta

In the framework of collinear QCD factorization, the leading twist scattering amplitudes for deeply virtual Compton scattering (DVCS) and timelike Compton scattering (TCS) are intimately related thanks to analytic properties of leading and…

High Energy Physics - Phenomenology · Physics 2020-03-18 O. Grocholski , H. Moutarde , B. Pire , P. Sznajder , J. Wagner

We revisit the phenomenology of the deep exclusive electroproduction of a lepton pair, i.e. double deeply virtual Compton scattering (DDVCS), in view of new experiments planned in the near future. The importance of DDVCS in the…

High Energy Physics - Phenomenology · Physics 2023-06-14 K. Deja , V. Martinez-Fernandez , B. Pire , P. Sznajder , J. Wagner

We outline the twist-two analysis of deeply virtual Compton scattering (DVCS)within the conformal partial wave expansion of the amplitude, represented as a Mellin--Barnes integral. The complete next-to-leading order results, including…

High Energy Physics - Phenomenology · Physics 2017-08-23 K. Kumerički , D. Müller , K. Passek-Kumerički

The Generalized Parton Distributions (GPD) have drawn a lot of interest from the theoretical community since 1997, but also from the experimental community and especially at Jefferson Lab. First, the results for Deeply Virtual Compton…

High Energy Physics - Experiment · Physics 2017-08-23 F. Sabatie

Deeply virtual Compton scattering is a fascinating process which can provide a tomographic view of nuclei and bound nucleons. The first experimental results for $^4$He targets, recently released at Jefferson Lab, have been analyzed here in…

Nuclear Theory · Physics 2021-02-03 Sara Fucini , Sergio Scopetta , Michele Viviani

Radiative corrections to the cross sections of photon electroproduction and the single spin asymmetries induced by the interference between the Bethe Heitler and deep virtual Compton scattering amplitudes are calculated within the leading…

High Energy Physics - Phenomenology · Physics 2018-07-25 Igor Akushevich , Alexander Ilyichev

Deeply Virtual Compton Scattering and electroproduction of mesons involve amplitudes that are analytic in energy. Analyticity enables Dispersion Relations (DR's) for such amplitudes, relating real and imaginary parts. Lately it has been…

High Energy Physics - Phenomenology · Physics 2009-08-18 Gary R. Goldstein , Simonetta Liuti