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Related papers: Pion Structure Function $F_{2}^{\pi}$ in the Valon…

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Based on both the constituent quark picture and the instanton model for QCD vacuum, we calculate the unpolarized and polarized gluon distributions in the constituent quark and in the nucleon. Our approach consists of the two main steps. At…

High Energy Physics - Phenomenology · Physics 2016-05-04 Nikolai Kochelev , Hee-Jung Lee , Baiyang Zhang , Pengming Zhang

The correlation between vorticity and spin alignment in heavy-ion collisions can be probed through polarization measurements of hadrons, whose total spin originates from both constituent-quark spins and orbital angular momentum in the…

The alternative to the standard formulation of QPM in the infinite momentum frame is suggested. The proposed approach does not require any extra assumptions in addition, consistently takes into account the parton transversal momenta and…

High Energy Physics - Phenomenology · Physics 2016-08-24 P. Zavada

Calculations are presented of the longitudinal structure function $F_L(x, Q^2)$. We use next-to-leading order expressions in QCD $({\cal{O}}(\alpha_s^2))$ plus parton densities determined previously from global fits to data on deep…

High Energy Physics - Phenomenology · Physics 2014-11-17 Edmond L. Berger , Ruibin Meng

We show how the parton distributions in the photon can be accurately measured in the photoproduction of large-pt jets at HERA. A short review is given of the beyond Leading Logarithm formalism for the photon structure function, with a…

High Energy Physics - Phenomenology · Physics 2009-09-25 M. Fontannaz

We summarize the key results of a recent global analysis of inclusive single-charged-hadron production in high-energy colliding-beam experiments. In the framework of the parton model of quantum chromodynamics at next-to-leading order (NLO),…

High Energy Physics - Phenomenology · Physics 2010-03-25 Bernd A. Kniehl

We calculate the transition form factor of the neutral pion where one photon is virtual and another photon is real in the model where the light constituent quark mass and the quark-pion vertex are taken to be momentum independent. Radiative…

High Energy Physics - Phenomenology · Physics 2013-08-09 A. E. Dorokhov , E. A. Kuraev

We explore quark-hadron duality in semi-inclusive pion electroproduction on proton and neutron targets. Using the spin-flavor symmetric quark model, we compute ratios of pi+ and pi- cross sections for both unpolarized and polarized…

Nuclear Theory · Physics 2009-12-04 F. E. Close , W. Melnitchouk

Results of experiments probing the structure of the pomeron at hadron colliders and at HERA are reviewed. By renormalizing the pomeron flux factor in diffraction dissociation as dictated by unitarity, a picture emerges from the data in…

High Energy Physics - Phenomenology · Physics 2007-05-23 Konstantin Goulianos

The first measurement of diffractive processes in deep inelastic scattering at the HERA collider is analysed in terms of a "soft" pomeron exchange model. The partonic structure of the pomeron which emerges in this picture is determined…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Golec--Biernat

Parton distribution functions (PDFs) describe the structure of hadrons as composed of quarks and gluons. They are needed to make predictions for short-distance processes in high-energy collisions and are determined by fitting to cross…

High Energy Physics - Phenomenology · Physics 2020-11-11 Karol Kovarik , Pavel M. Nadolsky , Davison E. Soper

In this contribution, an approach for a unified description of the pion electromagnetic form factor, in the space- and time-like regions, within a constituent quark model on the light front, will be reviewed. Our approach is based on i) the…

High Energy Physics - Phenomenology · Physics 2017-08-23 J. P. B. C. de Melo , T. Frederico , E. Pace , G. Salme`

At leading twist the transverse-momentum dependent parton distributions of the pion consist of two functions, the unpolarized $f_{1,\pi}(x,\boldsymbol k^{\, 2}_\perp)$ and the Boer-Mulders function $h_{1,\pi}^{\perp}(x,\boldsymbol k^{\,…

High Energy Physics - Phenomenology · Physics 2014-11-04 B. Pasquini , P. Schweitzer

We demonstrate that the global properties of the ``rapidity gap'' events, observed at HERA, can be understood based on electron-gluon scattering as the underlying partonic process. Using the measured inclusive structure function $F_2$ to…

High Energy Physics - Phenomenology · Physics 2009-02-20 W. Buchmuller , A. Hebecker

A unified set of predictions for pion, kaon and nucleon gravitational form factors is obtained using a symmetry-preserving truncation of each relevant quantum field equation. A crucial aspect of the study is the self-consistent…

High Energy Physics - Phenomenology · Physics 2025-04-01 Zhao-Qian Yao , Yin-Zhen Xu , Daniele Binosi , Minghui Ding , Zhu-Fang Cui , Khépani Raya , Craig D. Roberts , José Rodríguez-Quintero

The Electron--Ion Collider in China (EicC) provides an excellent opportunity to explore the internal structure of pions and kaons via the Sullivan process in deep-inelastic scattering (DIS). In this study, we present detailed projections…

High Energy Physics - Experiment · Physics 2025-12-02 Zongyang Lu , Zihan Yu , Ting Lin , Yu-Tie Liang , Rong Wang , Wan Chang , Weizhi Xiong

We provide a consistent regularization procedure for calculating hadron structure functions in a chiral quark model. The structure functions are extracted from the absorptive part of the forward Compton amplitude in the Bjorken limit. Since…

High Energy Physics - Phenomenology · Physics 2009-10-31 H. Weigel , E. Ruiz Arriola , L. Gamberg

It is demonstrated that the global properties of the rapidity gap events at HERA can be understood based on electron-gluon scattering and a non-perturbative mechanism of colour neutralization. Using the measured inclusive structure function…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Buchmuller , A. Hebecker

The goal of this paper is to construct a Frobenius splitting on $G/U$ via the Poisson geometry of $(G/U,\pi_{G/U})$, where $G$ is a semi-simple algebraic group of classical type defined over an algebraically closed field of characteristic…

Algebraic Geometry · Mathematics 2019-08-05 Jun Peng , Shizhuo Yu

Recent data on the proton F_2 structure function in the resonance region suggest that local quark-hadron duality works remarkably well for each of the low-lying resonances, including the elastic, to rather low values of Q^2. We derive…

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