Related papers: Determination of the $\Sigma$--$\Lambda$ mixing an…

As a direct source of information on chiral symmetry breaking within QCD, the sigma commutator is of considerable importance. With recent advances in the calculation of hadron masses within full QCD it is of interest to see whether the…

We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic $\La_c$ decay we obtain a reasonable agreement with…

In this study, we calculate the mixing angles between the axial-vector mesons $D_{1(s1)} - D_{1(s1)}^\prime$ and $B_{1(s1)} - B_{1(s1)}^\prime$ using the QCD sum rules approach. Our results are $\theta_1 = 28.2 \pm 0.6^\circ$, $\theta_2 =…

Using the general form of the (Sigma^0) and (Lambda) currents, the (Sigma^0-Lambda) transition magnetic moment is calculated in framework of the light cone QCD sum rules. A comparison of our result on this quantity with the existing…

SU2 isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects. These mass differences are small. Between the Sigma and Lambda the mass splitting…

We use QCD sum rule approach to calculate the masses of the ground-state Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryonic masses…

The $q^2$ dependence of the $\pi$-$\eta$ mixing amplitude is examined with the use of QCD sum rules. The linear slope of the mixing function $\theta(q^2)$ is found to be much smaller than that for $\rho$-$\omega$ mixing. Thus the mixing…

We calculate the Lamb, fine and hyperfine shifts in $b\bar b$ with $n=2$, $l=0,1$. Radiative corrections as well as leading nonperturbative corrections (known to be due to the gluon condensate) are taken into account. The calculation is…

The $\Lambda$ $\to$ $\Sigma^0$ transition magnetic moment is computed in the QCD sum rules approach. Three independent tensor structures are derived in the external field method using generalized interpolating fields. They are analyzed…

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…

In this talk, I present new results [1] obtained from QCD spectral sum rules (QSSR), on the bag constant parameters entering in the analysis of the B^0_{(s)}-\bar B^0_{(s)} mass-differences. Taking the average of the results from the…

Two strategies are taken into account to determine the $f_1(1420)$-$f_1(1285)$ mixing angle $\theta$. (i) First, using the Gell-Mann-Okubo mass formula together with the $K_1(1270)$-$K_1(1400)$ mixing angle $\theta_{K_1}=(-34\pm 13)^\circ$…

The Heavy Quark Effective Theory provides a systematic method to estimate a mixing angle of hadron states in a heavy quark, such as the charm quark (c) and the bottom quark (b). By using this method, the mixing angle of the baryons…

Using the general form of (Sigma_Q) and (Lambda_Q) (Q=b or c) currents, (Sigma_Q-Lambda_Q) transition magnetic moments are calculated in framework of the light cone QCD sum rules method. In this approach nonperturbative effects are…

Motivated by the recently constructed interpolation field for S$_{11}$(1535), we propose a new interpolating field for $\Lambda$(1405). Using this current, we calculate the mass of $\Lambda$(1405) based on the conventional QCD sum rule…

We investigate the $K_1(1270)-K_1(1400)$ mixing caused by the flavor $SU(3)$ symmetry breaking. The mixing angle is expressed by a $K_{1A}\to K_{1B}$ matrix element induced by the operators that breaks flavor $SU(3)$ symmetry. The QCD…

The method of QCD sum rules in the presence of external elctromagnetic fields is used to calculate the $\Omega$ magnetic moment $\mu_{\Omega^-}$ and $\Sigma^0$-$\Lambda$ transition magnetic moment $\mu_{\Sigma^0\Lambda}$, with the…

In this paper, we show how the mixing angles of the standard parameterization add when multiplying the quark and leptonic mixing matrices, i.e., we derive explicit sum rules for the quark and leptonic mixing angles. In this connection, we…

We use the method of QCD sum rules to investigate a possible hybrid baryon with the quantum numbers of the $\Lambda$. Using a current composed of uds quarks in a color octet and a gluon, a strange hybrid, the $\Lambda_H$ is found about 500…

We calculate the branching ratio of $\Lambda_b \to \Lambda \gamma$ in the standard model using the PQCD method. The predicted branching ratio $B(\Lambda_b \to \Lambda \gamma)$ is about $(4.3\sim 8.6)\times 10^{-8}$, with reasonable…