相关论文: About QCD sum rules for pion-nucleon coupling
The Goldberger-Miyazawa-Oehme sum rule is used to extract the pion-nucleon coupling constant from experimental $\pi$N information. Chiral perturbation theory is exploited in relating the pionic hydrogen s-wave level shift and width results…
We calculate the $D^*D\pi$ and $B^*B\pi$ couplings using QCD sum rules on the light-cone. In this approach, the large-distance dynamics is incorporated in a set of pion wave functions. We take into account two-particle and three-particle…
We calculate the hadronic coupling constants $g_{NN\pi}$ and $g_{\rho\pi\pi}$ in QCD, including dynamical quarks in the framework of staggered fermions in the lattice approach. For the nucleon--pion coupling we obtain $g_{NN\pi} = 13.8 \pm…
The couplings of pions with heavy baryons g_2 (\Sigma^*, \Sigma) and g_3(\Sigma^*, \Lambda) are studied with light-cone QCD sum rules in the leading order of heavy quark effective theory. Both sum rules are stable. Our results are…
The \pi NN^* and \eta NN^* coupling constants are studied in the QCD sum rule ($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…
In this article, the three point QCD sum rules is used to compute the strong coupling constants of vertices containing the strange bottomed ( charmed ) mesons with pion. The coupling constants are calculated, when both the bottom ( charm )…
The pion nucleon vertex function at finite temperature is studied in the framework of: (a) the thermal (linear) sigma model to leading (one-loop) order, and (b) a thermal QCD-Finite Energy Sum Rule. Results from both methods indicate that…
We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input…
To leading order in alpha_s, the leading and non-leading 1/m_b corrections to the excited g_B^(**) meson coupling g_B^(**)BPi is calculated in the framework of QCD spectral moment sum rules in the full theory. Our prediction is in good…
Using QCD sum rules, we compute the diagonal meson-baryon couplings, $\pi NN$, $\eta NN$, $\pi \Xi\Xi$, $\eta \Xi\Xi$, $\pi \Sigma \Sigma$ and $\eta \Sigma \Sigma$, from the baryon-baryon correlation function with a meson, $i\int d^4x…
For the heavy baryons $\Xi_c$ and $\Xi_b$ the coupling constants $g_{\Xi_c\Xi_c\pi}$ and $g_{\Xi_b\Xi_b\pi}$ are calculated in the framework of light cone QCD sum rules. The most general form of the interpolating field of $\Xi_Q$ is used in…
We derive the light cone QCD sum rule for the $\eta NN$ coupling constant $g_{\eta NN} $. The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the two external…
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…
We calculate the leading twist valence quark distribution in the pion in the framework of QCD sum rules with nonlocal condensates. Particular attention has been paid to the correct account for the bilocal power corrections.
We show that at certain values of QCD condensates the nucleon QCD sum rules with "pole+continuum" model for the hadron spectrum obtain an unphysical solution. This provides constrains for the values of condensates to be consistent with…
We present results of a calculation of the electromagnetic pion form factor within a framework of QCD Sum Rules with nonlocal condensates and using a perturbative spectral density which includes \mathcal{O}(\alpha_s) contributions.
We present an analysis of QCD sum rules for pion form factor in next-to-leading order of perturbation theory for the case of pseudoscalar pion currents. The essential instanton contribution is reanalysed with account for present more…
The bounds on the values of gluon, four-quark and quark-gluon condensates are derived from the requirement of consistency of the sum rules for various correlators of the hybrid current $a_{\mu}=g\bar d\gamma_{\rho}\tilde G_{\rho\mu}u$. The…
We calculate the "pi Sigma Lambda" and "pi Sigma Sigma" coupling constants in light cone QCD sum rules for the structure "sigma_{alpha beta} gamma_5 p^alpha q^beta". A comparison of our results on these coupling constants with prediction of…
We study the mass of a nucleon in a nucleus using a model recently introduced for a nucleon current with a pion cloud component. The method of QCD sum rules is used to determine the mass shifts for nucleons to first order in nuclear density…