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Related papers: Backward DVCS on the pion in Sullivan processes

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We study in QCD the physics of deeply-virtual Compton scattering (DVCS)---the virtual Compton process in the large s and small t kinematic region. We show that DVCS can probe a new type of off-forward parton distributions. We derive an…

High Energy Physics - Phenomenology · Physics 2014-11-17 Xiangdong Ji

We emphasize the complementarity of timelike and spacelike studies of deep exclusive processes, taking as an example the case of timelike Compton Scattering (TCS) i.e. the exclusive photoproduction of a lepton pair with large invariant…

High Energy Physics - Phenomenology · Physics 2015-05-28 B. Pire , L. Szymanowski , J. Wagner

We have developped a fitting code based on the leading-twist handbag Deep Virtual Compton Scattering (DVCS) amplitude in order to extract the Generalized Parton Distributions (GPD) information from DVCS observables in the valence region. In…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Guidal

We show that the Fourier transform of the Deeply Virtual Compton Scattering (DVCS) amplitude with respect to the skewness variable $\zeta$ at fixed invariant momentum transfer squared $t$ provides a unique way to visualize the structure of…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. J. Brodsky , D. Chakrabarti , A. Harindranath , A. Mukherjee , J. P. Vary

We consider backward vector meson exclusive electroproduction off nucleons in the framework of collinear QCD factorization. Nucleon to vector meson transition distribution amplitudes arise as building blocks for the corresponding factorized…

High Energy Physics - Phenomenology · Physics 2015-05-13 B. Pire , K. Semenov-Tian-Shansky , L. Szymanowski

We show that exclusive production of a pair of high transverse momentum photons in pion-nucleon collisions can be systematically studied in QCD factorization approach if the photon's transverse momentum $q_T$ with respect to the colliding…

High Energy Physics - Phenomenology · Physics 2022-08-24 Jian-Wei Qiu , Zhite Yu

Double Deeply Virtual Compton Scattering (DDVCS) is the only experimental channel for the determination of the dependence of the Generalized Parton Distributions (GPDs) on both the average and the transferred momentum independently. The…

Nuclear Experiment · Physics 2021-12-20 S. Zhao , A. Camsonne , D. Marchand , M. Mazouz , N. Sparveris , S. Stepanyan , E. Voutier , Z. W. Zhao

We describe results for the pion distribution amplitude (PDA) at the non-perturbative scale $\mu=~$2GeV by projecting the Poincar\'e-covariant Bethe-Salpeter wave-function onto the light-front and use it to investigate the ultraviolet…

High Energy Physics - Phenomenology · Physics 2014-07-03 Peter C Tandy

We summarize here our investigations on the deeply virtual Compton scattering (DVCS) in the color dipole approach, implementing the dipole cross section through the saturation model. The role played by its QCD evolution and the skewedness…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laurent Favart , Magno V. T. Machado

An overview on the new COMPASS II experimental programme is presented. The main topics include a study of Primakoff reactions, generalised parton distributions via deeply virtual Compton scattering and transverse momentum dependent…

High Energy Physics - Experiment · Physics 2011-09-14 Eva-Maria Kabuss

The QCD evolution of the pion distribution amplitude (DA) $\phi_\pi(x,Q^2)$ is computed for several commonly used models. Our analysis includes the nonperturbative form predicted by light-front holographic QCD, thus combining the…

High Energy Physics - Phenomenology · Physics 2011-08-12 Stanley J. Brodsky , Fu-Guang Cao , Guy F. de Teramond

Deeply Virtual Compton Scattering in the near forward kinematic region is the golden access to Generalized Parton Distributions. We studied the O(alphaS) corrections to the scattering amplitude for both spacelike and timelike kinematics…

High Energy Physics - Phenomenology · Physics 2015-06-18 H. Moutarde , B. Pire , F. Sabatié , L. Szymanowski , J. Wagner

Using the approach based on conformal symmetry we calculate the two-loop coefficient function for the axial-vector contributions to two-photon processes in the $\overline{\rm MS}$ scheme. This is the last missing element for the complete…

High Energy Physics - Phenomenology · Physics 2021-11-17 V. M. Braun , A. N. Manashov , S. Moch , J. Schoenleber

Detailed predictions for the scaled pion-photon transition form factor are given, derived with the method of light-cone sum rules and using pion distribution amplitudes with two and three Gegenbauer coefficients obtained from QCD sum rules…

High Energy Physics - Phenomenology · Physics 2014-03-03 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

Following Polchinski and Strassler [1] and our previous work [2], we study high-energy pion scattering in the holographic QCD hard-wall model. In particular, we focus on comparing our predictions for the angular dependence of $\pi^{+}…

High Energy Physics - Phenomenology · Physics 2026-04-08 Adi Armoni , Dorin Weissman

We investigate the deeply virtual Compton scattering (DVCS) in the color dipole approach, implementing the dipole cross section through the saturation model, which interpolates successfully between soft and hard regimes. The imaginary and…

High Energy Physics - Phenomenology · Physics 2011-09-13 L. Favart , M. V. T. Machado

We use general relations between the Transition Distribution Amplitudes (TDAs), entering the description of the p -> pi0 transition, and the proton Distribution Amplitudes (DAs) in the soft-pion limit to estimate the size of the amplitude…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. P. Lansberg , B. Pire , L. Szymanowski

We discuss all-order factorization for the virtual Compton process at next-to-leading power (NLP) in the $\Lambda_{\rm QCD}/Q$ and $\sqrt{-t}/Q$ expansion (twist-3), both in the double-deeply-virtual case and the single-deeply-virtual case.…

High Energy Physics - Phenomenology · Physics 2025-01-31 Jakob Schoenleber , Robert Szafron

The Deeply Virtual Compton Scattering (DVCS) $\gamma^* p \to \gamma p$ cross section has been measured with the H1 detector at HERA with an increased precision and in an extended kinematic domain: at photon virtualities $4<Q^2<80$ GeV$^2$,…

High Energy Physics - Experiment · Physics 2007-05-23 L. Favart

In the context of nucleon structure studies, Generalized Parton Distributions (GPDs) are crucial for understanding the correlation between the longitudinal momentum and the transverse position of partons inside the nucleon. A privileged…

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