Related papers: Meson-Baryon Couplings Revisited
We use the method of double pole QCD sum rule which is basically a fit with two exponentials of the correlation function, where we can extract the masses and decay constants of mesons as a function of the Borel mass. We apply this method to…
We calculate the $\rho$ meson couplings between the heavy hybrid doublets H^h/S^h/M^h/T^h and the ordinary q\bar{Q} doublets in the framework of the light-cone QCD sum rule. The sum rules obtained rely mildly on the Borel parameters in…
We calculate the processes $\gamma p \to K^0 \Sigma^+ , K^+ \Sigma^0, K^+ \Lambda$ in three flavor heavy baryon chiral perturbation theory to one loop. Some low--energy constants are fixed from single baryon properties while others are…
Baryon masses and nucleon \sigma-terms are studied with the effective theory that combines the chiral and 1/Nc expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the…
Masses and current couplings of the charmonium and bottomonium hybrids $ \overline{c}gc$ and $\overline{b}gb$ with spin-parities $J^{\mathrm{PC} }=0^{++},\ 0^{+-},\ 0^{-+},\ 0^{--}$ and $1^{++},\ 1^{+-},\ 1^{-+},\ 1^{--}$ are calculated…
According to the Coleman-Glashow null theorem if all the symmetry breaking effects belong to the same regular representation (octet in the case of SU(3) and {\bf 15} in the case of SU(4)) and are generated in a tadpole type mechanism, the…
The cross sections of the reaction $pp \to N K Y$ for $K^+$ or $K^0$ mesons and $\Lambda$ or $\Sigma$ hyperons are calculated within the boson exchange model including pion and kaon exchange diagrams. We analyze the dependence of the…
In this article, we study the mass spectrum of the low-lying triply heavy hybrid baryon, which consists of three valence heavy quarks in a color octet and one valence gluon, with spin-parity $J^P=(\frac{1}{2})^+$ via QCD sum rules. This is…
QCD sum rules using polynomial kernels are used to evaluate the strong part of the proton-neutron mass difference DeltaM_np in a model independent fashion. The result for the mass difference turns out to depend sensitively on the value of…
From an SU(2)$\otimes $SU(2) chiral quark potential model incorporating spontaneous chiral symmetry breaking the asymptotic $\pi $ and $\sigma $ exchange pieces of the $NN$ potential are generated. From them the $\pi NN$ and $\sigma NN$…
The decay constants of the charmed heavy pseudoscalar D and D_s mesons are revisited within a recently developed novel approach to dispersive QCD sum rules which relies on an unprejudiced implementation of quark-hadron duality. The proposed…
Inspired by recent developments of moose models we reconsider low-energy effective theories of Goldstone bosons, gauge fields and chiral fermions applied to low-energy QCD and to Higgs-less electroweak symmetry breaking. Couplings and the…
Renormalized coupling constants g_{2k} that enter the critical equation of state and determine nonlinear susceptibilities of the system possess universal values g*_{2k} at the Curie point. They are calculated, along with the ratios R_{2k} =…
Within an extended chiral constituent quark model, three- and five-quark structure of the $S_{01}$ resonance $\Lambda(1405)$ is investigated with respect to the coupling constants $g^2_{\Lambda^* \pi \Sigma}$ and $g^2_{\Lambda^* \bar{K}…
We compute the strong coupling constant $G_{B^{**} B \pi} \; (G_{D^{**} D \pi})$, where $B^{**}$ ($D^{**}$) is the $0^+$ $P-$wave $b \bar q \; (c \bar q)$ state, by QCD sum rules and by light-cone sum rules. The two methods give compatible…
It is proposed that meson resonances are linear combinations of q-qbar and meson-meson (MM); baryon resonances are combinations of qqq and meson-baryon (MB). Mixing between these combinations arises via decays of confined states to…
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…
We propose a new approach to construct QCD sum rules for the pi NN coupling constant, g, starting from the vacuum-to-pion correlation function of the interpolating fields of two nucleons and taking its matrix element with respect to nucleon…
In the paper we investigate observational constraints on coupling to gravity constant parameter $\xi$ using distant supernovae SNIa data, baryon oscillation peak (BOP), the cosmic microwave background radiation (CMBR) shift parameter, and…
Recent measurements of the branching ratios for the decays $\omega\to\pi^0\pi^0\gamma$ and $\rho^0\to\pi^0\pi^0\gamma$ lead to coupling constants of the $V\sigma\gamma$-interaction ($V$ is a vector meson) one order of magnitude smaller than…