Related papers: Predicting D -> sigma pi
We present results for the strong widths corresponding to the $\Sigma_b\to \Lambda_b\, \pi$ and $\Sigma_b^{*}\to \Lambda_b\, \pi$ decays. We apply our model in Ref. Phys. Rev. D 72, 094022 (2005) where we previously studied the…
I consider a model based on a quark--meson interaction Lagrangian. The transition amplitudes are evaluated by computing diagrams in which heavy and light mesons are attached to quark loops. The light chiral symmetry relations and the heavy…
The pi-pi interaction amplitudes have been calculated using a three coupled channel model both with and without constraints imposed by chiral models. Roy's equations have been used to compare the amplitudes and to study the role played by…
We use a non-perturbative approach which combines coupled channel Lippmann-Schwinger equations with meson-meson potentials provided by the lowest order chiral Lagrangian. By means of one parameter, a cut off in the momentum of the loop…
The nonperturbative, Dyson-Schwinger equation approach to solving QCD provides a straightforward, microscopic description of dynamical chiral symmetry breaking and confinement. It is an ideal tool for the study of pion observables. This is…
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…
We propose a constituent quark model to evaluate heavy decay constants and form factors relevant for B=>D(*) semileptonic transitions. We show that the model reproduces the scaling laws dictated by the spin-flavour symmetry in the heavy…
We study the nature of the scalar D_0 meson from the viewpoint of chiral symmetry. With the linear representation of chiral symmetry, we construct the D pi scattering amplitude satisfying the chiral low-energy theorem, in which the D_0…
We evaluate the form factors describing the exclusive decay B-> pi l nu by using a Constituent Quark-Meson model based on an effective quark-meson Lagrangian (CQM). The model allows for an expansion in the pion momenta and we consider terms…
Constituent quark masses can be determined quite well from experimental data in several ways and one can obtain fairly accurate values for all six $m_q$. The strong quark-meson coupling $g=2\pi /\sqrt{3}$ arises from the quark-level linear…
We merge heavy quark effective theory with staggered chiral perturbation theory to calculate heavy-light (B, D) meson quantities. We present results at NLO for the $B(D)$ meson decay constant in the partially quenched and full QCD cases,…
We study in detail the prediction for the semileptonic decays $\bar{B} \to D (D^*) \pi \ell \bar{\nu}$ by heavy quark and chiral symmetry. The branching ratio for $\bar{B} \to D \pi \ell \bar{\nu}$ is quite significant, as big as…
The SU(3) breaking effects due to light quark masses on heavy meson masses, decay constants ($F_{D}, F_{D_{s}}$) and the form factor for semileptonic $\overline{B}\rightarrow D^{(\ast)} l\bar{\nu}_{l}$ transitions are formulated in chiral…
We describe the effective heavy meson lagrangian for S- and P-wave heavy-light mesons in terms of a model based on meson-quark interactions, where mesonic transition amplitudes are represented by diagrams with heavy mesons attached to loops…
The $\pi\pi$ scattering amplitude in the $\sigma$-channel is studied at finite baryonic density in the framework of a chiral unitary approach which successfully reproduces the meson meson phase shifts and generates the $f_0$ and $\sigma$…
We propose a phenomenological three component model describing the decay amplitude of the process $D_{s}^{+} \ra 3\pi$. The first component is a constant background, the second one is a Breit-Wigner amplitude associated to a quasi two-body…
The meson scattering and electroproduction amplitudes in the D13, D33 and D15 partial waves are calculated in a coupled-channel formalism incorporating quasi-bound quark-model states, extending our previous studies of the P11, P33 and S11…
We present a calculation of the \beta-term for D^* --> D gamma within a heavy-light chiral quark model. Within the model, soft gluon effects in terms of the gluon condensate with lowest dimension are included. Also, calculations of 1/m_c…
An effective potential in a meson-meson system is discussed based on the SU(3) chiral constituent quark model, and the analytic form of the potential is explicitly given. In addition, the effective potential is employed to study the bound…
In the covariant level-classification scheme of hadrons proposed recently, the existence of "chiral particles", scalar and axial-vector mesons as the partners of the ground-state pseudo-scalar and vector mesons, respectively, were predicted…