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Related papers: Spin effects in the pion holographic light-front w…

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In this work we present for the first time the comprehensive study of the Melosh spin rotation effects in diffractive electroproduction of S-wave heavy quarkonia off a nucleon target. Such a study has been performed within the color dipole…

High Energy Physics - Phenomenology · Physics 2019-03-27 Michal Krelina , Jan Nemchik , Roman Pasechnik , Jan Cepila

We calculate the pion transition form factor ${\cal F}_{\pi^0\gamma^*\gamma^*}(q_1^2,q_2^2)$, which describe the interaction of an on-shell pion with two off-shell photons, using lattice QCD simulations with two degenerate flavors of…

High Energy Physics - Lattice · Physics 2016-12-07 Antoine Gérardin , Harvey B. Meyer , Andreas Nyffeler

We determine the pion parton distribution functions (PDFs) from its light-front wave functions, obtained using the holographic Schr\"odinger equation of light-front chiral QCD combined with the 't Hooft equation in (1+1)-dimensional QCD at…

High Energy Physics - Phenomenology · Physics 2026-05-15 Jiangshan Lan , Satvir Kaur , Chandan Mondal

The pion electromagnetic form factor is calculated at lower and higher momentum transfer in order to explore constituent quark models and the differences among those models. In particular, the light-front constituent quark model is utilized…

High Energy Physics - Phenomenology · Physics 2016-10-19 J. P. B. C. de Melo , Rômulo Moreira Moita , Kazuo Tsushima

We study the gravitational form factors of the proton and some of its mechanical properties. We use a holographic model based on the AdS/CFT correspondence, in which a deformation in the anti-de Sitter background geometry is considered. By…

High Energy Physics - Phenomenology · Physics 2026-05-26 Ayrton Nascimento , Henrique Boschi-Filho

We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition region at intermediate Q^2. Combining Drell-Yan data on the leading twist quark distribution in the pion with a…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. Melnitchouk

Being simultaneously a bound state and a pseudo-Goldstone boson of chiral symmetry breaking, the pion is an ideal probe of the intertwined phenomena of confinement and chiral symmetry breaking in QCD. Here, we compute the low energy pion…

High Energy Physics - Phenomenology · Physics 2025-08-19 Jeff Forshaw , Ruben Sandapen

This work addresses more to the technical rather than to the physical problem, how to calculate analytically the form factor $F(Q)$, the associated mean-square radius $<r^2>$, and the distribution function $\Phi(x,Q^2)$ for a given…

High Energy Physics - Phenomenology · Physics 2016-09-06 Hans-Christian Pauli

We study the photon-to-meson transition form factors (TFFs) F_{M \gamma}(Q^2) for gamma gamma^* \to M using light-front holographic methods. The Chern-Simons action, which is a natural form in 5-dimensional anti-de Sitter (AdS) space, leads…

High Energy Physics - Phenomenology · Physics 2011-11-02 Stanley J. Brodsky , Fu-Guang Cao , Guy F. de Teramond

The holographic graviton soft-wall model, introduced to describe the spectrum of scalar and tensor glueballs, is improved to incorporate the realization of chiral-symmetry as in QCD. Such a goal is achieved by including the longitudinal…

High Energy Physics - Phenomenology · Physics 2022-08-10 M. Rinaldi , F. A. Ceccopieri , V. Vento

We compute the pion inclusive momentum distribution in heavy-ion collisions at AGS energies, assuming thermal equilibrium and accounting for density and expansion effects at the time of decoupling. We compare to data on mid rapidity charged…

Nuclear Theory · Physics 2009-10-31 Alejandro Ayala , Julio Barreiro , Luis M. Montaño

We discuss, how planned measurements at KLOE-2 of the (pi^0 -> gamma gamma) decay width and the (gamma^* gamma -> pi^0) transition form factor can improve estimates for the numerically dominant pion-exchange contribution to hadronic…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andreas Nyffeler

The spin effects in nucleon-nucleon scattering are calculated in the framework of the dynamic model taking into account interactions at large distances and the strong form factors; the model factorization of the $NN$ amplitude into the…

High Energy Physics - Phenomenology · Physics 2009-09-25 S. V. Goloskokov , O. V. Selyugin

Non-leading contribution to the pion electromagnetic form factor which comes from the pion twist-3 wave function is analyzed in the modified hard scattering approach (MHSA) proposed by Li and Sterman. This contribution is enhanced…

High Energy Physics - Phenomenology · Physics 2009-08-25 Fu-Guang Cao , Yuan-Ben Dai , Chao-Shang Huang

The off-shell pion electromagnetic form factors are explored with corresponding off-shell light-front wave functions modeled by constituent quark and anti-quark. We apply the Mandelstam approach for the microscopic computation of the form…

High Energy Physics - Phenomenology · Physics 2024-11-07 Jurandi Leão , J. Pacheco B. C. de Melo , T. Frederico , Ho-Meoyng Choi , Chueng-Ryong Ji

We evaluate the next-to-next-to-leading order corrections to the hard-scattering amplitude of the photon-to-pion transition form factor. Our approach is based on the predictive power of the conformal operator product expansion, which is…

High Energy Physics - Phenomenology · Physics 2009-11-07 B. Melic , D. Müller , K. Passek-Kumericki

In this work, we analyze the energy density and the stress distribution inside the pion derived from gravitational form factors in top-down holographic QCD. In particular, we show that the dominance of the scale anomaly in the confining…

High Energy Physics - Phenomenology · Physics 2025-12-24 Daisuke Fujii , Akihiro Iwanaka , Mitsuru Tanaka

The two-photon-exchange (TPE) effects in the process $e^+e^- \rightarrow \pi^+\pi^-$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs)…

High Energy Physics - Phenomenology · Physics 2018-09-12 Hong-Yu Chen , Hai-Qing Zhou

Starting from the Hamiltonian equation of motion in QCD we find a single variable light-front equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum.…

High Energy Physics - Phenomenology · Physics 2009-09-11 Guy F. de Teramond , Stanley J. Brodsky

A novel method is employed to compute the pion electromagnetic form factor, F_\pi(Q^2), on the entire domain of spacelike momentum transfer using the Dyson-Schwinger equation (DSE) framework in quantum chromodynamics (QCD). The DSE…

Nuclear Theory · Physics 2015-06-16 L. Chang , I. C. Cloet , C. D. Roberts , S. M. Schmidt , P. C. Tandy