Related papers: A gluonic mechanism for B --> D eta'
We evaluate the form factors governing the exclusive decays B->rho l nu, B->a_1 l nu, by using an effective quark-meson lagrangian. The model is based on meson-quark interactions, and the computation of the mesonic transition amplitudes is…
The effective $\eta^\prime g^* g^*$ vertex is studied in the standard (Brodsky-Lepage) and modified hard scattering approaches for arbitrary gluon virtualities in the time-like and space-like regions. The contribution of the gluons in the…
An effective, low-energy, field theory of s-wave quarkonia, constituent heavy quarks, and gluons is constructed which is manifestly gauge invariant. The interaction Lagrangian has the form of a twist expansion, as typically encountered in…
We calculate the shear viscosity $\eta$ to entropy density $s$ ratio $\eta /s$ of a gluon plasma in kinetic theory including the gg->gg and gg<->ggg processes. Due to the suppressed contribution to $\eta$ in the gg->gg forward scattering,…
We give an overview of chiral quark models, both for the pure light sector and the heavy-light sector. We describe how such models can be bosonized to obtain welWe give an overview of chiral quark models, both for the pure light sector and…
We apply a coupled-channel formalism incorporating quasi-bound quark-model states to calculate pion scattering into eta N, K Lambda and K Sigma channels, as well eta p, eta n, K+Lambda, and K0Sigma+ photo-production processes. The…
We calculate the top quark loop corrections to the Zbb vertex in the chiral lagrangian of the dynamical electroweak symmetry breaking theory. We use the effective lagrangian based on coset space SU(2) X U(1) / U(1) with the gauge…
We have searched for the rare decay of the eta meson $\eta \to e^{+}e^{-}$ using the CLEO II detector. The $\eta$'s were produced in $e^{+}e^{-}$ collisions with 10 GeV center-of-mass energy at the Cornell Electron Storage Ring (CESR). We…
We propose a method for implementing the large-Nc, large-Nf limit of QCD at the effective Lagrangian level. Depending on the value of the ratio Nf/Nc, different patterns of chiral symmetry breaking can arise, leading in particular to…
We have studied charmless two-body B decays involving $\eta$ and $\eta'$ in the framework of QCD improved factorization appraoch. The spectator hard scattering mechanism for $\eta'$ production have been re-examined and extended, which…
The supernumerous eta(1405) is considered a strong candidate for the pseudoscalar glueball. In a phenomenological chiral approach, we consider a mixing scenario of bare pseudoscalar (n bar n) and (s bar s) quarkonia with the glueball. We…
We present a factorization framework that takes into account the production of heavy quarks through gluon splitting in the thrust distribution for e+ e- --> hadrons. The explicit factorization theorems and some numerical results are…
Motivated by the successful application of Heavy Quark Effective Field Theory in describing decays from heavy to light mesons, this work explores its applicability to the semileptonic decays of charmed mesons. So in this paper we…
It is pointed out that decays of the type $B \to D \bar{D}$ have no factorizable contributions, unless at least one of the charmed mesons in the final state is a vector meson. The dominant contributions to the decay amplitudes arise from…
We study glueball $G$ production in gluonic penguin decay $B\to G + X_s$, using the next-to-leading order $b\to s g^*$ gluonic penguin interaction and effective couplings of a glueball to two perturbative gluons. Subsequent decays of a…
In this work, we employ the effective vertices for interaction between diquarks (scalar or axial-vector) and gluon where the form factors are derived in terms of the B-S equation, to obtain the potential for baryons including a light quark…
Exclusive hadronic B-meson decays into two-body final states consisting of a light pseudoscalar or vector meson along with an eta or eta' meson are of great phenomenological interest. Their theoretical analysis involves decay mechanisms…
We calculate the expected branching fraction of the second-class-current decay tau --> pi eta' nu, motivated by a a recent experimental upper-limit determination of this quantity. The largest contribution to the branching fraction is due to…
We derive the chiral effective Lagrangian for heavy-light mesons in the heavy quark limit from QCD under proper approximations. The low energy constants in the effective Lagrangian are expressed in terms of the light quark self-energy. With…
In this work, the $\eta^\prime$ meson photoproduction near threshold is studied in the quark model framework. A pseudovector effective Lagrangian is introduced for the $\eta^\prime NN$ coupling and the newly published data from the SAPHIR…