Nucleon quark distributions in a covariant quark–diquark model
نویسندگان
چکیده
منابع مشابه
Nucleon Form Factors in a Covariant Diquark – Quark Model †
In a model where constituent quarks and diquarks interact through quark exchange the Bethe–Salpeter equation in ladder approximation for the nucleon is solved. Quark and diquark confinement is effectively parametrized by choosing appropriately modified propagators. The coupling to external currents is implemented via nontrivial vertex functions for quarks and diquarks to ensure gauge invariance...
متن کاملNucleon Properties in the Covariant Quark-Diquark Model
In the covariant quark-diquark model the effective Bethe-Salpeter (BS) equations for the nucleon and the ∆ are solved including scalar and axialvector diquark correlations. Their quark substructure is effectively taken into account in both, the interaction kernel of the BS equations and the currents employed to calculate nucleon observables. Electromagnetic current conservation is maintained. T...
متن کاملNucleon Form Factors in the Covariant Diquark–Quark Model
The nucleon is described as a bound state of a quark and an extended diquark. Hereby the notion “diquark” refers to the modelling of separable correlations in the two–quark Green’s functions. Binding of quarks and diquarks takes place via an exchange interaction and is therefore related to the Pauli principle for three– quark states. Fully Poincaré covariant nucleon amplitudes are calculated fo...
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We report the first study of the nucleon where the full Poincaré-covariant structure of the three-quark amplitude is implemented in the Faddeev equation. We employ an interaction kernel which is consistent with contemporary studies of meson properties and aspects of chiral symmetry and its dynamical breaking, thus yielding a comprehensive approach to hadron physics. The resulting current-mass e...
متن کاملThe Quark Spin Distributions of the Nucleon
The quark helicity measured in polarized deep inelastic scattering is different from the quark spin in the rest frame of the nucleon. We point out that the quark spin distributions ∆qRF (x) are connected with the quark helicity distributions ∆q(x) and the quark transversity distributions δq(x) by an approximate relation: ∆qRF (x) +∆q(x) = 2δq(x). This relation will be useful in order to measure...
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ژورنال
عنوان ژورنال: Physics Letters B
سال: 2005
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2005.06.065