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Related papers: Wide-angle pion-Delta(1232) photoproduction

200 papers

We summarize recent developments in understanding the concept of generalized parton distributions (GPDs), its relation to nucleon structure, and its application to high-Q2 electroproduction processes. Following a brief review of QCD…

High Energy Physics - Phenomenology · Physics 2009-08-24 C. Weiss

We review our results on a new class of $2 \to 3$ exclusive processes, as a probe of both chiral-even and chiral-odd quark GPDs. We consider the exclusive photoproduction of a photon-meson pair, in the kinematics where the pair has a large…

High Energy Physics - Phenomenology · Physics 2024-10-08 Goran Duplančić , Saad Nabeebaccus , Kornelija Passek-K. , Bernard Pire , Lech Szymanowski , Samuel Wallon

This is an English translation of my 1977 Russian preprint. It contains the first explicit definition of the pion distribution amplitude (DA), the expression for the pion form factor asymptotics in terms of the pion DA, and formulates the…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. V. Radyushkin

We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…

Nuclear Theory · Physics 2021-08-04 N. Rijneveen , A. M. Gasparyan , H. Krebs , E. Epelbaum

In this work, we report a lattice calculation of $x$-dependent valence pion generalized parton distributions (GPDs) at zero skewness with multiple values of the momentum transfer $-t$. The calculations are based on an $N_f=2+1$ gauge…

High Energy Physics - Lattice · Physics 2025-02-14 Heng-Tong Ding , Xiang Gao , Swagato Mukherjee , Peter Petreczky , Qi Shi , Sergey Syritsyn , Yong Zhao

We develop a consistent technique for the calculation of real photon emission in hard exclusive processes, which is based on the background field formalism and allows a convenient separation of hard electromagnetic and soft hadronic…

High Energy Physics - Phenomenology · Physics 2010-04-05 P. Ball , V. M. Braun , N. Kivel

The purpose of this work is to do a systematic feasibility study of measuring in backward region deeply virtual Compton scattering on the pion in Sullivan processes in the framework of collinear QCD factorization where pion to photon…

High Energy Physics - Phenomenology · Physics 2024-08-30 Abigail Rodrigues Castro , Cedric Mezrag , Jose M. Morgado Chávez , Bernard Pire

The chiral-odd transversity generalized parton distributions (GPDs) of the nucleon can be accessed experimentally through the exclusive photoproduction process gamma + N -> pi + rho + N', in the kinematics where the meson pair has a large…

High Energy Physics - Phenomenology · Physics 2015-05-18 M. El Beiyad , B. Pire , M. Segond , L. Szymanowski , S. Wallon

Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Xing-Gang Wu , Tao Huang

We analyze the electroproduction of pseudoscalar mesons within the handbag approach. To investigate these reactions, we consider the leading-twist contribution together with the transversity twist-3 effects that are crucial in the…

High Energy Physics - Phenomenology · Physics 2012-11-26 S. V. Goloskokov

Nuclear Generalized Parton Distributions (GPDs), a unique tool to access several crucial features of nuclear structure, could be measured in the coherent channel of hard exclusive processes, such as deep electroproduction of photons and…

Nuclear Theory · Physics 2007-05-23 Sergio Scopetta

Exclusive $\pi^0$ electroproduction from nucleons at large $Q^2$ can be described by Generalized Parton Distributions (GPDs), particularly the chiral odd subset related to transversity. These GPDs can be accessed experimentally from various…

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

Generalized parton distributions (GPDs) are three-dimensional structure functions of hadrons, and they can reveal the orbital-angular-momentum contributions to the nucleon spin. Therefore, GPDs are important for solving the proton spin…

High Energy Physics - Phenomenology · Physics 2020-01-08 Qin-Tao Song

In this talk it is reported on an analysis of hard exclusive electroproduction of pseudoscalar mesons within the handbag approach. It is argued that recent measurements of pion electroproduction performed by HERMES and CLAS clearly indicate…

High Energy Physics - Phenomenology · Physics 2025-01-09 P. Kroll

We calculate large mass diphoton exclusive photoproduction in the framework of collinear QCD factorization at next to leading order in {\alpha}s and at leading twist. Collinear divergences of the coefficient function are absorbed by the…

High Energy Physics - Phenomenology · Physics 2021-08-02 Oskar Grocholski , Bernard Pire , Paweł Sznajder , Lech Szymanowski , Jakub Wagner

Generalized Parton Distributions offer a new way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the need to supplement the experimental study of DVCS by its crossed version, timelike…

High Energy Physics - Phenomenology · Physics 2011-09-27 B. Pire , K. Semenov-Tian-Shansky , L. Szymanowski , J. Wagner

A model for the twist-3 wave function $\psi_p(x,\mathbf{k_\perp})$ of the pion has been constructed based on the moment calculation by applying the QCD sum rules, whose distribution amplitude has a better end-point behavior than that of the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tao Huang , Xing-Gang Wu

Generalized parton distributions (GPDs) have been investigated in the deeply virtual Compton scattering (DVCS) to solve the proton spin puzzle. On the other hand, the generalized distribution amplitudes (GDAs) can be studied in the…

High Energy Physics - Phenomenology · Physics 2018-08-21 Qin-Tao Song

Generalized parton distributions (GPDs) encoding multidimensional information of hadron partonic structure appear as the building blocks in a factorized description of hard exclusive reactions. The nucleon GPDs have been accessed by deeply…

Nuclear Experiment · Physics 2016-07-01 Takahiro Sawada , Wen-Chen Chang , Shunzo Kumano , Jen-Chieh Peng , Shinya Sawada , Kazuhiro Tanaka

Off-shell effects in generalized parton distributions (GPDs) of the pion, appearing, e.g., in the Sullivan process, are considered. Due to the lack of crossing symmetry, the moments of GPDs involve also odd powers of the skewness…

High Energy Physics - Phenomenology · Physics 2023-03-31 Wojciech Broniowski , Vanamali Shastry , Enrique Ruiz Arriola