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Related papers: Quark Distributions in a Medium

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Double parton distributions at small distances between the two partons are dominated by a mechanism in which the two observed partons originate from the splitting of a single parton. This contribution can be computed in terms of…

High Energy Physics - Phenomenology · Physics 2026-02-23 Markus Diehl , Peter Ploessl

Generalized parton distributions have been introduced in recent years as a suitable theoretical tool to study the structure of the nucleon. Unifying the concepts of parton distributions and hadronic form factors, they provide a…

High Energy Physics - Phenomenology · Physics 2011-09-30 Sigfrido Boffi , Barbara Pasquini

Transverse momentum dependent (TMD) distribution correlators can be parametrized in terms of TMD parton distribution functions (PDFs), or TMDs for short. We provide an overview of the leading-twist quark and gluon TMDs, both in momentum…

High Energy Physics - Phenomenology · Physics 2016-12-21 Tom van Daal

We perform a quenched lattice calculation of the first moment of twist-two generalized parton distribution functions of the proton, and assess the total quark (spin and orbital angular momentum) contribution to the spin of the proton.

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Göckeler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers

Applying arguments based on the operator product expansion for a three-point correlator and relying on quark-hadron duality, we derive an expression for the skewed (non-forward) parton distribution in the pion in the case of a…

High Energy Physics - Phenomenology · Physics 2009-08-25 Alexander P. Bakulev , Rusko Ruskov , Klaus Goeke , N. G. Stefanis

We analyze the moments of parton distribution functions in the pion calculated in lattice QCD, paying particular attention to their chiral extrapolation. Using the lowest three non-trivial moments calculated on the lattice, we assess the…

High Energy Physics - Lattice · Physics 2008-11-26 W. Detmold , W. Melnitchouk , A. W. Thomas

We show how quark-hadron duality can emerge for valence spin averaged structure functions, and for the non-forward distributions of Deeply Virtual Compton Scattering. Novel factorisations of the non-forward amplitudes are proposed. Some…

High Energy Physics - Phenomenology · Physics 2009-11-07 Frank E. Close , Qiang Zhao

In the quest to understand QCD there are a number of outstanding challenges. Here we focus on one of these, namely what one expects to happen to the structure of a hadron when it is immersed in a nuclear medium. We argue that the necessary…

Nuclear Theory · Physics 2014-02-24 Anthony W. Thomas

The generalized parton distributions of the pion are studied within different light-front approaches for the quark-hadron and quark-photon vertices, exploring different kinematical regions in both the valence and non-valence sector. Moments…

High Energy Physics - Phenomenology · Physics 2014-11-20 T. Frederico , E. Pace , B. Pasquini , G. Salme'

We review the current status of theories and experiments aiming at an understanding and a determination of the properties of light vector and scalar mesons inside strongly interacting hadronic matter, with an emphasis on linking calculated…

Nuclear Theory · Physics 2011-03-10 Ulrich Mosel , Stefan Leupold , Volker Metag

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

An improved analysis method to extract quark helicity distributions in leading order (LO) QCD from semi-inclusive double spin asymmetries in deep inelastic scattering is presented. The method relies on the fact that fragmentation functions,…

Data Analysis, Statistics and Probability · Physics 2017-03-28 Jörg Pretz

Diffractive parton distribution functions give the probability to find a parton in a hadron if the hadron is diffractively scattered. We provide an operator definition of these functions and discuss their relation to diffractive deeply…

High Energy Physics - Phenomenology · Physics 2014-11-17 Arjun Berera , Davison E. Soper

Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when target and/or quark are transversely polarized. In combination with the final state…

High Energy Physics - Phenomenology · Physics 2010-01-15 Matthias Burkardt

We study the transverse momentum distribution for a $pair$ of heavy quarks produced in hadron-hadron interactions. Predictions for the large transverse momentum region are based on exact order $\alpha_s^3$ QCD perturbation theory. For the…

High Energy Physics - Phenomenology · Physics 2010-11-01 Edmond L. Berger , Ruibin Meng

We show that the gauge-invariant transverse-momentum-dependent (TMD) quark distribution function can be expressed as a sum of all higher-twist collinear parton matrix elements in terms of a transport operator. From such a general…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zuo-tang Liang , Xin-Nian Wang , Jian Zhou

We investigate one-particle semi-inclusive processes in lepton-hadron scattering. In unpolarized scattering order $Q^{-1}$ corrections appear only when transverse momenta are detected. We consider the twist two and three matrix elements and…

High Energy Physics - Phenomenology · Physics 2009-12-15 J. Levelt , P. J. Mulders

The proper support of generalized parton distributions from relativistic constituent quark models with pointlike constituents is studied. The correct support is guaranteed when the vertex function does not depend on the relative…

High Energy Physics - Phenomenology · Physics 2010-12-13 A. Van Dyck , T. Van Cauteren , J. Ryckebusch

In relativistic heavy ion collisions, the cross section of heavy hadron production via the combination of a heavy quark with a light one from the quark-gluon matter can be factorized. It is the convolution of twist-4 combination matrix…

High Energy Physics - Phenomenology · Physics 2007-05-23 Shi-Yuan Li

We review the present state of knowledge regarding the transverse polarisation (or transversity) distributions of quarks. After some generalities on transverse polarisation, we formally define the transversity distributions within the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Vincenzo Barone , Alessandro Drago , Philip G. Ratcliffe