387 research outputs found

    Longitudinal momentum densities in transverse plane for nucleons

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    We present a study of longitudinal momentum densities (p+densitiesp^+ \rm densities) in the transverse impact parameter space for uu and dd quarks in both unpolarized and transversely polarized nucleons by taking a two dimensional Fourier transform of the gravitational form factors with respect to the momentum transfer in the transverse direction. The gravitational form factors are obtained by the second moments of GPDs. Here we consider the GPDs of two different soft-wall models in AdS/QCD correspondence.Comment: 12 pages, 9 figures; text modifie

    Helicity-dependent generalized parton distributions for nonzero skewness

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    We investigate the helicity dependent generalized parton distributions (GPDs) in momentum as well as transverse position (impact) spaces for up and down quarks in a proton when the momentum transfer in both the transverse and longitudinal directions are nonzero. The GPDs are evaluated using the light-front wavefunctions of a quark-diquark model for nucleon where the wavefunctions are constructed by the soft-wall AdS/QCD correspondence. We also express the GPDs in the boost-invariant longitudinal position space.Comment: 13 pages, 10 figures; to appear in Eur. Phys. J. C. arXiv admin note: text overlap with arXiv:1509.0059

    Nucleon to Δ\Delta transition form factors and empirical transverse charge densities

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    We investigate the nucleon to Δ\Delta transition form factors in a soft-wall AdS/QCD model and a light-front quark-diquark model inspired by AdS/QCD. From the transition form factors we evaluate the transition charge densities which influences the nucleon to Δ\Delta excitation. Here we consider both the unpolarized and the transversely polarized cases. The AdS/QCD predictions are compared with available experimental data and with the results of the global parameterization, MAID2007.Comment: 9 pages, 5 figures; minor text modified, version to appear in Eur. Phys. J.

    Chiral-odd generalized parton distributions for proton in a light-front quark-diquark model

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    We present a study of the chiral-odd generalized parton distributions for uu and dd quarks in a proton using the light front wave functions of the scalar quark-diquark model for nucleon constructed from the soft-wall AdS/QCD correspondence. We obtain the GPDs in terms of overlaps of the LFWFs. Numerical results for chiral-odd GPDs in momentum as well as transverse position spaces considering both zero and nonzero skewness(ζ\zeta) are presented. For nonzero skewness, the GPDs are also evaluated in longitudinal position space.Comment: 24 pages, 10 figure

    Transverse charge and magnetization densities in holographic QCD

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    We present a study of flavor structures of transverse charge and anomalous magnetization densities for both unpolarized and transversely polarized nucleons. We consider two different models for the electromagnetic form factors in holographic QCD. The flavor form factors are obtained by decomposing the Dirac and Pauli form factors for nucleons using the charge and isospin symmetry. The results are compared with two standard phenomenological parametrizations.Comment: minor modifications, some references correcte

    Wigner distributions for an electron

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    We study the Wigner distributions for a physical electron, which reveal the multidimensional images of the electron. The physical electron is considered as a composite system of a bare electron and photon. The Wigner distributions for unpolarized, longitudinally polarized and transversely polarized electron are presented in transverse momentum plane as well as in impact parameter plane. The spin-spin correlations between the bare electron and the physical electron are discussed. We also evaluate all the leading twist generalized transverse momentum distributions (GTMDs) for electron.Comment: 27 pages, 18 figures, text modified, version accepted in Nuclear Physics

    Gravitational form factors and angular momentum densities in light-front quark-diquark model

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    We investigate the gravitational form factors (GFFs) and the longitudinal momentum densities (p+p^+ densities) for proton in a light-front quark-diquark model. The light-front wave functions are constructed from the soft-wall AdS/QCD prediction. The contributions from both the scalar and the axial vector diquarks are considered here. The results are compared with the consequences of a parametrization of nucleon generalized parton distributions (GPDs) in the light of recent MRST measurements of parton distribution functions (PDFs) and a soft-wall AdS/QCD model. The spatial distribution of angular momentum for up and down quarks inside the nucleon has been presented. At the density level, we illustrate different definitions of angular momentum explicitly for an up and down quark in the light-front quark-diquark model inspired by AdS/QCD.Comment: 14 pages, 9 figures; version to appear in EPJ
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