Related papers: Consistent off-shell $\pi N N$ vertex and nucleon …
We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also…
Using Dyson--Schwinger equations, the nucleon propagator is analyzed nonperturbatively in a field--theoretical model for the pion--nucleon interaction. Infinities are circumvented by using pion--nucleon form factors which define the…
We study the influence of the virtual pion cloud in nuclear matter at finite densities and temperatures on the structure of the rho- and omega-mesons. The in-matter spectral function of the pion is obtained within a selfconsistent scheme of…
We compute the axial and pseudoscalar form factors of the nucleon in the Dyson-Schwinger approach. To this end, we solve a covariant three-body Faddeev equation for the nucleon wave function and determine the matrix elements of the…
A microscopic model of the electromagnetic form factor of the nucleon is developed in a hadronic framework, including pions, nucleons and the Delta-resonance explicitly. The space like on-shell form factors are reproduced and predictions…
In a recent Comment [arXiv:1206.3671] on our calculation of the pion contributions to the self-energy of the nucleon [arXiv:1201.4184], Ji, Melnitchouk and Thomas (JMT) correctly state that we obtain the same result as given by the…
Pion photoproduction amplitudes are calculated from a set of equations that have been derived by coupling an external photon to all places in a dressed pion-nucleon vertex. The calculation is consistent with gauge invariance, charge…
Pseudoscalar meson dominance has implications for nucleon structure which follow from an Extended Partial Conservation of the Axial Current (EPCAC). The minimal resonance saturation of the nucleon pseudoscalar form factor of the lowest…
The temperature and density dependence of the meson-nucleon vertex form factors is studied in the framework of thermofield dynamics. Results are obtained for two rather different nucleon-nucleon potentials: the usual Bonn potential and the…
Changes in the meson-nucleon coupling constant and the vertex form factor in nuclear matter are studied in a modified Skyrme Lagrangian including the sigma-meson field that satisfies the scale invariance. Renormalization of the axial-vector…
Nucleon and pion electromagnetic form factors are evaluated in the spacelike region within a light-front constituent quark model, where eigenfunctions of a mass operator, reproducing a large set of hadron energy levels, are adopted and…
We investigate nuclear matter properties in the relativistic Brueckner approach. The in-medium on-shell T-matrix is represented covariantly by five Lorentz invariant amplitudes from which we deduce directly the nucleon self-energy. To…
We present a quantitative study of the role played by different components characterizing the nucleon-nucleon interaction in the evolution of the nuclear shell structure. It is based on the spin-tensor decomposition of an effective two-body…
We present a light-front determination of the pionic contribution to the nucleon self-energy, $\Sigma_\pi$, to second-order in pion-baryon coupling constants that allows the pion-nucleon vertex function to be treated in a model-independent…
We present the isovector axial, induced pseudoscalar, and pseudoscalar form factors of the nucleon using three twisted-mass fermion ensembles with degenerate up- and down-, strange-, and charm-quarks with masses tuned to their physical…
Symmetric nuclear matter is studied within the conserving, self-consistent T-matrix approximation. This approach involves off-shell propagation of nucleons in the ladder diagrams. The binding energy receives contributions from the…
We analyze the matrix elements of the pseudoscalar density with pion-quantum numbers $I^G J^{PC}= 1^- 0^{-+}$ in the nucleon in terms of dispersion relations, PCAC and pQCD asymptotic sum rules for the pseudoscalar form factor. We show that…
We present a calculation of nuclear matter which goes beyond the usual quasi-particle approximation in that it includes part of the off-shell dependence of the self-energy in the self-consistent solution of the single-particle spectrum. The…
We develop a relativistic covariant and unitary description of the pion-nucleon interaction in a hadron-exchange model. The model is based on the solution of a dimensionally reduced (quasipotential) Bethe-Salpeter equation for the…
We present results for the isovector axial, induced pseudoscalar, electric, and magnetic form factors of the nucleon. The calculations were done using $2+1+1$-flavor HISQ ensembles generated by the MILC collaboration with lattice spacings…