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We present the generalized parton distributions (GPDs) for the valence quarks of the pion and the kaon in both momentum space and position space within the basis light-front quantization framework. These GPDs are obtained from the…

High Energy Physics - Phenomenology · Physics 2021-12-16 Lekha Adhikari , Chandan Mondal , Sreeraj Nair , Siqi Xu , Shaoyang Jia , Xingbo Zhao , James P. Vary

A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance…

High Energy Physics - Experiment · Physics 2015-06-23 E. Seder , A. Biselli , S. Pisano , S. Niccolai , the CLAS Collaboration

In the framework of the QCD parton model, we study unpolarized scattering of high energy real photons from a proton target into lepton pairs and a system of hadrons. For a given parametrization of parton distributions in the proton, we…

High Energy Physics - Phenomenology · Physics 2017-08-23 Ales Psaker

Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton $\vec{e}\vec{p} \to e' p'\gamma$ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally…

High Energy Physics - Experiment · Physics 2015-03-25 S. Pisano , A. Biselli , S. Niccolai , E. Seder , M. Guidal , M. Mirazita , the CLAS Collaboration

We discuss a possibility to measure the spin-dependent part of the forward Compton scattering amplitude through interference effects of the Bethe-Heitler and virtual Compton scattering mechanisms in photoproduction of e+e- pairs at small…

Nuclear Theory · Physics 2007-05-23 A. I. L'vov , S. Scopetta , D. Drechsel , S. Scherer

Exclusive photoproduction of dileptons, gamma p ->l+ l- p, will be measured in ultraperipheral collisions at LHC. The mechanism where the lepton pair comes from a heavy timelike photon radiated from a quark interferes with the pure QED…

High Energy Physics - Phenomenology · Physics 2008-12-18 B. Pire , L. Szymanowski , 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

Double Deeply Virtual Compton Scattering (DDVCS) is a promising channel for Generalized Parton Distribution (GPD) studies as it is a generalization of the Deeply Virtual Compton Scattering (DVCS) and Timelike Compton Scattering (TCS)…

High Energy Physics - Phenomenology · Physics 2025-02-05 J. S. Alvarado , M. Hoballah , E. Voutier

Generalized Parton Distributions (GPDs) are multidimensional structure functions of hadrons, encoding mechanical and spin properties through the correlation of the momentum and transverse position of partons. While channels like Deeply…

High Energy Physics - Phenomenology · Physics 2025-09-16 J. S. Alvarado , M. Hoballah , E. Voutier

Spacelike and timelike generalized parton distributions (GPDs) have been investigated in charged-lepton scattering and electron-positron collisions via deeply virtual Compton scattering and two-photon processes, respectively. Furthermore,…

High Energy Physics - Phenomenology · Physics 2022-03-03 S. Kumano , R. Petti

Unpolarized and beam-polarized four-fold cross sections $\frac{d^4 \sigma}{dQ^2 dx_B dt d\phi}$ for the $ep\to e^\prime p^\prime \gamma$ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the…

High Energy Physics - Experiment · Physics 2015-11-25 H. S. Jo , F. X. Girod , H. Avakian , V. D. Burkert , M. Garçon , M. Guidal , V. Kubarovsky , S. Niccolai , P. Stoler , the CLAS Collaboration

We describe a new way to access the chiral odd transversity parton distribution in the proton through the photoproduction of lepton pairs. The basic ingredient is the interference of the usual Bethe Heitler or Drell-Yan amplitudes with the…

High Energy Physics - Phenomenology · Physics 2009-09-02 B. Pire , L. Szymanowski

The generalized parton distributions (GPDs) have emerged as a universal tool to describe hadrons in terms of their elementary constituents, the quarks and the gluons. Deeply virtual Compton scattering (DVCS) on a proton or neutron ($N$), $e…

Nuclear Experiment · Physics 2015-10-16 Angela Biselli

Generalized Parton Distributions (GPDs) have emerged over the 1990s as a powerful concept and tool to study nucleon structure. They provide nucleon tomography from the correlation between transverse position and longitudinal momentum of…

High Energy Physics - Phenomenology · Physics 2021-02-03 Shengying Zhao , Eric Voutier

The study of exclusive processes in photon - induced interactions allow us to probe the generalized parton distributions (GPDs), which provide information about the 3 dimensional description of the quark and gluon content of hadrons. In…

High Energy Physics - Phenomenology · Physics 2023-03-01 Ya-Ping Xie , V. P. Goncalves

Generalized Parton Distributions (GPDs) offer a new way to access the quark and gluon nucleon structure. We advocate the need to supplement the experimental study of deeply virtual Compton scattering by its crossed version, timelike Compton…

High Energy Physics - Phenomenology · Physics 2011-11-28 B. Pire , L. Szymanowski , J. Wagner

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

In a scenario where the constituent quarks are composite systems, Generalized Parton Distributions (GPDs) are built from wave functions to be evaluated in a Constituent Quark Model (CQM), convoluted with the GPDs of the constituent quarks…

High Energy Physics - Phenomenology · Physics 2007-05-23 Sergio Scopetta , Vicente Vento

Generalized Parton Distributions (GPDs) are multidimensonal structure functions that encode the information about the internal structure of hadrons. Using privileged channels such as Deeply Virtual Compton Scattering (DVCS) or Timelike…

Nuclear Experiment · Physics 2024-12-05 J. S. Alvarado , M. Hoballah , E. Voutier

Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of the usual parton distributions for the case when long-distance information is accumulated in…

High Energy Physics - Phenomenology · Physics 2016-11-23 A. V. Radyushkin