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Related papers: Pion and kaon valence-quark parton distribution fu…

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We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a…

High Energy Physics - Lattice · Physics 2016-04-20 Constantia Alexandrou

Parton distribution functions (DFs) are defining expressions of hadron structure. Exploiting the role of effective charges in quantum chromodynamics, an algebraic scheme is described which, given any hadron's valence parton DFs at the…

High Energy Physics - Phenomenology · Physics 2023-06-07 Pei-Lin Yin , Yin-Zhen. XuID , Zhu-Fang Cui , Craig D. Roberts , José Rodríguez-Quintero

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 present a model for the structure of baryons in which the valence partons interact through a linear potential. This model can be derived from QCD in the approximation where transverse momenta are ignored. We compare the valence quark…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. S. Krishnaswami

We investigate the model dependence of no-helicity flip generalized parton distribution of the pion upon different approaches for the quark-hadron and quark-photon vertexes, in the spacelike region. In order to obtain information on…

High Energy Physics - Phenomenology · Physics 2009-11-06 T. Frederico , E. Pace , B. Pasquini , G. Salmé

We present results for the first two moments of the light-cone distribution amplitudes of the pion and kaon pseudo-scalar mesons and of the rho, K* and phi vector mesons. The calculations are performed on the RBC/UKQCD collaborations'…

High Energy Physics - Lattice · Physics 2019-08-14 P. A. Boyle , D. Brömmel , M. A. Donnellan , J. M. Flynn , A. Jüttner , C. T. Sachrajda

The unpolarized, helicity and transversity parton distribution functions of the nucleon are studied within a convolution model where the bare nucleon is dressed by its virtual meson cloud. Using light-front time-ordered perturbation theory,…

High Energy Physics - Phenomenology · Physics 2017-05-31 S. Kofler , B. Pasquini

We discuss a general diagrammatic description of n-point functions in the QCD instanton vacuum that resums planar diagrams, enforces gauge invariance and spontaneously broken chiral symmetry. We use these diagrammatic rules to derive the…

High Energy Physics - Phenomenology · Physics 2020-07-29 Arthur Kock , Yizhuang Liu , Ismail Zahed

A model for the parton distributions in hadrons is derived from simple physical arguments leading to an analytical expression for the valence distributions. The sea parton distributions arise mainly from pions in hadronic fluctuations.…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Edin , G. Ingelman , K. Torokoff

We analyze experimental data of nuclear structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios for obtaining optimum parton distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear PDFs are estimated…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , T. -H. Nagai

The earlier introduced method of calculation of quark distributions in hadrons, based on QCD sum rules, is improved. The imaginary part of the virtual photon forward scattering amplitude on some hadronic current is considered in the case,…

High Energy Physics - Phenomenology · Physics 2011-09-13 B. L. Ioffe , A. G. Oganesian

We compute the light-cone momentum distributions of pions in the nucleon in chiral effective theory using both pseudovector and pseudoscalar pion-nucleon couplings. For the pseudovector coupling we identify \delta-function contributions…

High Energy Physics - Phenomenology · Physics 2013-04-03 M. Burkardt , K. S. Hendricks , Chueng-Ryong Ji , W. Melnitchouk , A. W. Thomas

Optimum nuclear parton distributions are obtained by analyzing available experimental data on electron and muon deep inelastic scattering (DIS). The distributions are given at Q^2=1 GeV^2 with a number of parameters, which are determined by…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Hirai , S. Kumano , M. Miyama

We use detailed balance for a hadron composed of quark and gluon Fock states to obtain parton distributions in the proton and pion on the basis of a simple statistical model.

High Energy Physics - Phenomenology · Physics 2008-11-26 Mary Alberg , Ernest M. Henley

The high-$x$ data from the ZEUS Collaboration are used to extract parton density distributions of the proton deep in the perturbative regime of QCD. The data primarily constrain the up-quark valence distribution and new results are…

High Energy Physics - Phenomenology · Physics 2023-04-19 Ritu Aggarwal , Michiel Botje , Allen Caldwell , Francesca Capel , Oliver Schulz

Parton distribution functions (PDFs) are nonperturbative quantities describing the relation between a hadron and quarks and gluons within it. We propose to extract PDFs from QCD global analysis of "data" generated by lattice QCD…

High Energy Physics - Phenomenology · Physics 2018-10-24 Yan-Qing Ma , Jian-Wei Qiu

We present lattice QCD calculations of valence parton distribution function (PDF) of pion employing next-to-next-leading-order (NNLO) perturbative QCD matching. Our calculations are based on three gauge ensembles of 2+1 flavor highly…

In light of recent experimental progress in determining the pressure and shear distributions in the proton, these quantities are calculated in a model with confined quarks supplemented by the pion field required by chiral symmetry. The…

High Energy Physics - Phenomenology · Physics 2023-12-11 Shiryo Owa , A. W. Thomas , X. G. Wang

We report the first lattice QCD calculation of pion valence quark distribution with next-to-next-to-leading order perturbative matching correction, which is done using two fine lattices with spacings $a=0.04$ fm and $0.06$ fm and valence…

High Energy Physics - Lattice · Physics 2022-04-08 Xiang Gao , Andrew D. Hanlon , Swagato Mukherjee , Peter Petreczky , Philipp Scior , Sergey Syritsyn , Yong Zhao

The nucleon distribution amplitudes and the nucleon-to-pion transition distribution amplitudes are investigated at leading twist within the frame of a light-cone quark model. The distribution amplitudes probe the three-quark component of…

High Energy Physics - Phenomenology · Physics 2010-05-28 B. Pasquini , M. Pincetti , S. Boffi