Related papers: $\pi NN$ coupling determined beyond the chiral lim…
The \pi NN^* and \eta NN^* coupling constants are studied in the QCD sum rule ($N^* \equiv N(1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit. The operator product expansion is…
The light cone QCD sum rules are employed to calculate the $\pi N N(1535)$ coupling $g_{\pi N N^\ast}$. We study the two point correlation function of two nucleon currents sandwiched between the vacuum and the pion state. The contribution…
We estimate strong coupling constant between the negative parity nucleons with $\pi$ meson within the light cone QCD sum rules. A method for eliminating the unwanted contributions coming from the nucleon--nucleon and nucleon--negative…
We critically evaluate the isovector GMO sumrule for the charged $\pi N N$ coupling constant using recent precision data from $\pi ^-$p and $\pi^-$d atoms and with careful attention to systematic errors. From the $\pi ^-$d scattering length…
We show that polarized gamma p -> \pi^+ n in the threshold region is an excellent candidate for measuring the leading parity-violating pion-nucleon coupling h_{\pi NN}^{(1)} to an uncertainty of 20% if it has a natural size from dimensional…
We investigate the parity-violating $\pi NN$ Yukawa coupling constant $h^1_{\pi NN}$ within the framework of the SU(2) chiral quark-soliton model, based on the $\Delta S=0$ effective weak Lagrangian derived within the same framework. We…
We study relationship between the physical quantities that characterize pion-nucleon and nucleon-nucleon interaction on the basis of the fact that nuclear forces in the nucleon-nucleon system at low energies are mainly determined by the…
We show that the tail of the chiral two-pion exchange nucleon-nucleon potential is proportional to the $\pi N$ scalar form factor and discuss how it can be translated into effective scalar meson interactions. We then construct a kernel for…
The $\pi NN$ form factor $g_{\pi NN}(q^2)$ is obtained from a quenched lattice QCD calculation of the pseudoscalar form factor $g_P(q^2)$ of the proton with pion pole dominance. We find that $g_{\pi NN}(q^2)$ fitted with the monopole form…
The QCD sum rule calculation of the in-medium pion decay constants using pseudoscalar-axial vector correlation function, $i \int d^4x e^{ip\cdot x} < \rho| T[{\bar d}(x) i \gamma_5 u (x) {\bar u}(0) \gamma_\mu \gamma_5 d (0)] | \rho>$ is…
Effects of non-resonant photoproductions arising from two different $\pi NN$ couplings are investigated in the $\gamma N\to\pi\pi N$ reaction. We find that the pseudoscalar (PS) $\pi NN$ coupling is generally preferable to the pseudovector…
pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy…
We adopt the heavy baryon chiral perturbation theory to calculate the $\Sigma_cN$ interaction to the next-to-leading order. We consider the contact interactions, one-pion-exchange contributions, two-pion-exchange diagrams, and…
We derive spectral sum rules for a system with two quarks coupled to an imaginary isospin chemical potential in the \epsilon regime. The sum rules show an explicit dependence on the pion decay constant which should make it possible to…
The coupling constant of g_phi-pion-gamma decay is calculated using light cone QCD sum rules. A comparison of our result with the ones existing in the literature is presented.
The external-field QCD Sum Rules method is used to evaluate the coupling constant of the light isoscalar-scalar meson (``$\sigma$'' or \epsilon) to the nucleon. The contributions that come from the excited nucleon states and the response of…
The reaction $\gamma d\to \pi^+ nn$ is calculated up to order $\chi^{5/2}$ in chiral perturbation theory, where $\chi$ denotes the ratio of the pion to the nucleon mass. Special emphasis is put on the role of nucleon--recoil corrections…
Using general baryon interpolating fields $J_B$ for $B= N, \Xi, \Sigma, $ without derivative, we study QCD sum rules for meson-baryon couplings and their dependence on Dirac structures for the two-point correlation function with a meson…
We explore a consistent way to extend the partially conserved axial vector current (PCAC) relation and corresponding current algebra results. The paper includes investigations of a chiral Ward-Takahashi identity, the explicit chiral…
We have calculated coupling constants of a neutral pion with the lowest two nucleon resonances. This includes both the diagonal as well as non-diagonal coupling constants involving a nucleon resonance and a nucleon. For this, we first…