Related papers: Extraction of the $\pi NN$ coupling constant from …
As a first step to analyze the electromagnetic meson production reactions in the nucleon resonance region, the parameters of the hadronic interactions of a dynamical coupled-channel model, developed in {\it Physics Reports 439, 193 (2007)},…
A description of the NN scattering is constructed starting from the $\pi, \eta, \eta'$ pseudoscalar-, the $\rho, \phi, \omega$ vector-, and the $\varepsilon(600), a_0, f_0(1400)$ scalar - meson-nucleon coupling constants, which we obtain…
We study the strong vertices $N^*N\pi$, $N^*N^*\pi$ and $NN\pi$ in QCD, where $N^*$ denotes the negative parity $N (1535)$ state. We use the most general form of the interpolating currents to calculate the corresponding strong coupling…
In his recent publication of a NN phase shift analysis below 160 MeV, Henneck reports relatively large values for the mixing parameter $\epsilon_1$. Based on these results, Henneck suggests that the strength of the $\rho$-meson tensor…
We analyse the SM97 partial wave amplitudes for nucleon--nucleon (NN) scattering to 2.5 GeV, in which resonance and meson production effects are evident for energies above pion production threshold. Our analyses are based upon boson…
We evaluate the $\pi N$ coupling constant using a QCD sum rule based on the pion-to-vacuum matrix element of the correlator of two interpolating nucleon fields. The part of the correlator with Dirac structure $k\llap/\gamma_5$ is used,…
The quasi-free $\gamma d\to\pi^{-}p(p)$ differential cross section has been measured with CLAS at photon beam energies $E_\gamma$ from 0.445 GeV to 2.510 GeV (corresponding to $W$ from 1.311 GeV to 2.366 GeV) for pion center-of-mass angles…
We present the results of energy-dependent and single-energy partial-wave analyses of $\pi$N elastic scattering data with laboratory kinetic energies below 2.1~GeV. Resonance structures have been extracted using Breit-Wigner fits, speed…
A $NN\to NN^{\ast}(1440)$ transition potential, based on an effective quark-quark interaction and a constituent quark cluster model for baryons, is derived in the Born-Oppenheimer approach. The potential shows significant differences with…
We set up a general framework to describe $\pi\pi$ scattering below 1 GeV based on chiral low-energy expansion with possible spin-0 and 1 resonances. Partial wave amplitudes are obtained with the $N/D$ method, which satisfy unitarity,…
An important question about resonance extraction is how much resonance poles and residues extracted from data depend on a model used for the extraction, and on the precision of data. We address this question with the dynamical…
The simple model describing charge independence and charge symmetry breaking of the pion-nucleon coupling constant is proposed. The model, which has simple physical meaning and foundation, suggests directly proportional dependence of the…
We undertake a covariance error analysis of the pion-nucleon-nucleon coupling constants from the Granada-2013 np and pp database comprising a total of 6720 scattering data below LAB energy of 350 MeV. Assuming a unique pion-nucleon coupling…
We derive a set of coupled four-dimensional integral equations for the $NN-\pi NN$ system using our modified version of the Taylor method of classification-of-diagrams. These equations are covariant, obey two and three-body unitarity and…
The light cone QCD sum rules are derived for the $\pi NN$ coupling $g_{\pi NN}$ and $\pi NN(1535)$ coupling $g_{\pi NN^\ast}$. The contribution from the excited states and continuum is subtracted cleanly through double Borel transformation.…
We point out subtleties in the previous sum rule calculations of the $\pi NN$ coupling associated with using either the PV or the PS coupling schemes in modeling the phenomenological side. We propose a sum rule which is independent of the…
In the Yukawa model for nuclear forces, a simple relation between the charged and neutral pion-nucleon coupling constants is derived. The relation implies that the charged pion-nucleon coupling constant is larger than the neutral one since…
The latest $\pi N$ elastic scattering data are re-analysed to determine the coupling constant $g_c$ of the charged pion, using the dispersion relation for the invariant amplitude $B^{(+)}$. Depending on the choice of data-base, values…
We use QCD sum rules to obtain the weak parity-violating pion-nucleon coupling constant $f_{\pi NN}$. We find that $f_{\pi NN}\approx 2\times 10^{-8}$, about an order of magnitude smaller than the ``best estimates'' based on quark models.…
We present results using a new scaling variable, xi_w in modeling electron- and neutrino-nucleon scattering cross sections with effective leading order PDFs.Our model uses all inelastic charged lepton F_2 data (SLAC/BCDMS/NMC/HERA), and…