Related papers: Pseudoscalar--meson decuplet--baryon coupling cons…
We summarize recently improved results for the pseudoscalar [1,2] and vector [3] meson decay constants and their ratios from QCD spectral sum rules where N2LO + estimate of the N3LO PT and power corrections up to d< 6 dimensions have been…
We consider the predictions of chiral perturbation theory for $SU(3)$ breaking in the axial vector form factor $g_1$ measured in semileptonic hyperon decays. We confirm that if only octet baryon intermediate states are included, the…
We revisit QCD sum rules for the decay constants of heavy-light mesons. In the sum rules for the vector mesons B^*_(s) and D^*_(s) we improve the accuracy of OPE, taking into account the O(alpha_s^2) terms in the perturbative part and…
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 doubly charmed $\Xi_{cc}^{++} (ccu)$ state is the only listed baryon in PDG, which was discovered in the experiment. The LHCb collaboration gets closer to discovering the second doubly charmed baryon $\Xi_{cc}^{+} (ccd)$, hence the…
For tetraquarks of the form $T[(\bar{Q}q)(Q\bar{q})]$ we give sum rules for their decay coupling constants, taking into account the SU(3) symmetry breaking interactions to first order.
The decay constants of the pseudoscalar mesons B and B_s are evaluated from QCD sum rules for the pseudoscalar two-point function. Recently calculated perturbative three-loop QCD corrections are incorporated into the sum rule. An analysis…
Using the most general form of the interpolating currents, the coupling constants $g_{\Sigma_b\Sigma_b\pi}$ and $g_{\Sigma_c\Sigma_c\pi}$ are calculated within the light cone QCD sum rules approach. It is found that…
In this work, we investigate the semi-leptonic weak decays of spin-1/2 doubly-heavy baryons $\Xi_{QQ^{\prime}}$ into spin-3/2 singly-heavy baryons $\Sigma_{Q^{\prime}}^*$ within light-cone sum rules. Using the parallel components of the…
We explore the breaking effects of the $SU(3)$ flavor symmetry in the singly Cabibbo-suppressed anti-triplet charmed baryon decays of ${\bf B}_c\to {\bf B}_n M$, with ${\bf B}_c=(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$ and ${\bf B}_n(M)$ the baryon…
We present a sum-rule extraction of the decay constants of the D, Ds, B, and Bs mesons from the two-point correlator of heavy-light pseudoscalar currents [1]. Our main emphasis is laid on the control over the uncertainties in the decay…
We present a calculation of the SU(3)-breaking corrections to the hyperon transition vector form factors to $\mathcal{O}(p^4)$ in heavy baryon chiral perturbation theory with finite-range regularisation. Both octet and decuplet degrees of…
The pseudoscalar and pseudovector $\eta N$ coupling constants are calculated from an effective vertex associated with the $a_0(980)\pi N$ triangle diagram. The predicted values are in agreement with the ones concluded from fitting $\eta $…
We sketch a recent sum-rule extraction of the decay constants of the heavy pseudoscalar mesons D, D_s, B, and B_s from the two-point correlator of heavy-light pseudoscalar currents [1]. Our main emphasis lies on the control over all the…
Early B-physics experiments have left us with a number of puzzles in heavy flavour physics. New lattice calculations (with a greater understanding of QCD effects in the Standard Model) will be needed to support the increase in experimental…
The decay rates of $D^+\to\pi^+\pi^0$ and $D^0\to K^+\pi^-$ recently measured by CLEO give the ratios $R_1=2|V_{cs}/V_{cd}|^2\Gamma(D^+\to \pi^+\pi^0)/\Gamma(D^+\to\bar{K}^0 \pi^+)=3.29\pm 1.16$ and…
QCD sum rules are used to estimate the flavour SU(3)-symmetry violation in two-body B decays to pions and kaons. In the factorizable amplitudes the SU(3)-violation manifests itself in the ratio of the decay constants f_K/f_pi and in the…
We evaluate the $\pi N!N$, $\pi\Sigma\Sigma$, $\pi\Lambda\Sigma$, $K\Lambda N$ and $K \Sigma N $ coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the…
In this article, we calculate the strong coupling constant $g_{\Delta N\pi}$ and study the strong decay $\Delta^{++} \to p\pi$ with the light-cone QCD sum rules. The numerical value of the strong coupling constant $g_{\Delta N\pi}$ is…
We report on a recent study of the SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ up to $\mathcal{O}(p^4)$ in covariant baryon chiral perturbation theory with dynamical octet and decuplet contributions. The decuplet…