Related papers: Pseudoscalar meson dominance and nucleon structure
We derive generalisations of the Weingarten--Witten QCD mass inequalities for particular multi-hadron systems. For systems of any number of identical pseudo-scalar mesons of maximal isospin, these inequalities prove that interactions…
Earlier work suggested that the in-medium $\pi N$ threshold isovector amplitude $b_1(\rho)$ gets renormalized in pionic atoms by about 30% away from its $\rho=0$ free-space value, relating such renormalization to the leading low-density…
We study further the soft-wall AdS/QCD model with a cubic potential for the bulk scalar. We analyze the spectra of pseudoscalar, scalar, vector and axial-vector mesons. We also study the spin-1/2 nucleon spectrum and the pion-nucleon…
This paper is devoted to the interplay between p-wave, s-wave pion-nucleon/ nucleus interaction and in-medium pion-pion interaction with special emphasis on the role of the nuclear pionic scalar density driving a large amount of chiral…
A meson-exchange model for pion-nucleon scattering was previously constructed using a three-dimensional reduction scheme of the Bethe-Salpeter equation for a model Lagrangian involving \pi, \eta, N, \Delta, \rho, and \sigma fields. We…
Ambiguities in pseudoscalar-meson photoproduction, arising from incomplete experimental data, have analogs in pion-nucleon scattering. Amplitude ambiguities have important implications for the problems of amplitude extraction and resonance…
The mass spectra of nucleon resonances with spin 1/2, 3/2, and 5/2 are systematically studied in the constituent quark model with meson-quark coupling, which is inspired by the spontaneous breaking of chiral symmetry of QCD. The meson-quark…
Equal time, point to point correlation functions for spatially separated meson currents are calculated with respect to a variational construct for the ground state of QCD. With exact calculations, vector, axial vector and scalar channels…
We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the…
We study how the electromagnetic structure of the nucleon is influenced by a pion cloud. To this aim we make use of a constituent-quark model with instantaneous confinement and a pion that couples directly to the quarks. To derive the…
We introduce coupled channels of Bethe-Salpeter mesons both in the boundstate equation for mesons and in the mass gap equation for chiral symmetry. Consistency is insured by the Ward Identities for axial currents, which preserve the…
We take an approach to the Lambda non-mesonic weak decay in nuclei based on the exchange of mesons. The one pion and one kaon exchange are considered, together with the exchange of two pions, either correlated, leading to an important…
An approach for a Poincar\'e covariant description of nuclear structure and of lepton scattering off nuclei is proposed within the relativistic Hamiltonian dynamics in the light-front form. Indeed a high level of accuracy is needed for a…
We present a new analysis method that allows one to understand and model excited state contributions in observables that are dominated by a pion pole. We apply this method to extract axial and (induced) pseudoscalar nucleon isovector form…
Shell structure of low-lying neutron resonant levels in axially-symmetric quadrupole-deformed potentials is discussed, which seems analogous to that of weakly-bound neutrons. As numerical examples, nuclei slightly outside the…
We study the nuclear modification of the scalar QCD susceptibility, calculated as the derivative of the quark condensate with respect to the quark mass. We show that it has two origins. One is the low lying nuclear excitations. At normal…
We apply the perturbative chiral quark model (PCQM) to analyse low-energy nucleon properties: electromagnetic form factors, meson-nucleon sigma-terms and pion-nucleon scattering. Baryons are described as bound states of valence quarks…
We performed a precise calculation of physical quantities related to the axial structure of the nucleon using 2+1 flavor lattice QCD gauge configuration (PACS10 configuration) generated at the physical point with lattice volume larger than…
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…
We investigate the exclusive electroproduction of pi^+ mesons from nucleons. To leading twist, leading order alpha_s accuracy the corresponding production amplitude can be decomposed into pseudovector and pseudoscalar parts. Both can be…