Related papers: g-coupling (g_B*Bpi,g_D*Dpi); A quark model with D…
We compute the strong coupling constant $g_{P^* P \pi}$, with $P$ and $P^*$ respectively pseudoscalar and vector heavy mesons by using the QCD sum rules approach. Our computation is based on the evaluation of the time ordered product of…
In the framework of a QCD inspired relativistic potential model, we evaluate radiative decay rates of heavy mesons and their coupling with soft pions. The agreement with the existing experimental data is satisfactory. In the limit $m_Q \to…
By means of QCD simulations on the lattice, we compute the coupling of the heavy-light mesons to a soft pion in the static heavy quark limit. The gauge field configurations used in this calculations include the effect of N_f=2 dynamical…
We use a QCD relativistic potential model to compute the strong coupling constant $g$ appearing in the effective Lagrangian which describes the interaction of $0^-$ and $1^-$ $\bar q Q$ states with soft pions in the limit $m_Q \to \infty$.…
QCD sum rules are used to calculate the couplings of heavy-light quark pseudoscalar and vector mesons ($D, D^*$ and $B, B^*$) with soft pions, both for finite and infinitely heavy quark mass. The couplings are also computed in the framework…
We analyse pionic couplings of heavy mesons combining PCAC with the dispersion quark model to calculate the relevant transition form factors. Ground states and radial excitations are considered. For the ground state coupling constants the…
Form factors and decay widths for $D^{\ast}\rightarrow D \gamma$ and $D^{\ast}\rightarrow D \pi$ decays are estimated in a relativistic constituent quark model. Relativistic corrections due to light quarks are found to be substantial and to…
We calculate the strong coupling constants among the doubly heavy spin-$ \frac{3}{2} $ baryons $\Xi^*_{QQ}$ and $\Omega^*_{QQ}$, with $ Q $ and $ Q' $ being $ c$ or $ b $ quark, with light vector meson by means of the light-cone QCD sum…
In the heavy quark limit, there are three independent strong axial coupling constants in chiral Lagrangians for ground-state heavy hadrons: g in the meson sector, and g_1, g_2 in the baryon sector. The coupling g_2 is extracted from recent…
In the conventional QCD sum rule calculation for the $\pi NN$ coupling beyond the soft-pion limit, there are three distinct Dirac structures, each of which can be used to construct separate sum rule. We point out subtleties in the previous…
In this research, the strong coupling constants of the $D^*D_s^*K$, $D_1D_{s1}K$, $D^*D_sK$ and $D_1D_{s0}^*K$ vertices are evaluated, using the three-point QCD sum rules. In order to calculate the coupling constant of each vertex, either…
Within the conventional QCD sum rules, we calculate the $\pi NN$ coupling constant, $g_{\pi N}$, beyond the chiral limit using two-point correlation function with a pion. We consider the Dirac structure, $i\gamma_5$, at $m_\pi^2$ order,…
The couplings between the soft pion and the doublet of heavy-light mesons are basic parameters of the ChPT approach to the heavy-light systems. We compute the unquenched (Nf=2) values of two such couplings in the static heavy quark limit:…
We use the Dirac equation to study the mass spectrum of mesons with heavy-light quark combinations. First we study the Dirac equation with spherically symmetry and funnel potential, and apply them on the hydrogen-like atom problem to check…
We estimate the couplings in the Heavy Hadron Chiral Theory (HHCT) lagrangian from the QCD sum rules in an external axial field. We take into account the perturbative correction to the meson correlator in the infinite mass limit. With the…
The coupling constants of D*D$\pi$ and B*B$\pi$ strong interactions are computed in the effective quark model with chiral symmetry incorporating Heavy quark effective theory (HQET) and Chiral perturbation theory at the quark level with…
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…
We present a new chiral quark model for mesons involving a heavy and a light (anti-) quark. The model relates various combinations of a quark - meson coupling constant and loop integrals to physical quantities. Then, some quantities may be…
Light-cone QCD sum rules are employed to compute the strong coupling constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and (B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ doublets. The…
We study the spectra of the hybrid mesons containing one heavy quark ($q\bar{Q}g$) within the framework of QCD sum rules in the heavy quark limit. The derived sum rules are stable with the variation of the Borel parameter within their…