相关论文: Baryon Current Matrix Elements in a Relativistic Q…

We study the effects on oscillations in the neutral-Kaon system from lepton and hadron self-energy loops in the W-boson propagators. The corresponding W box diagrams are evaluated by attaching the external quark lines to covariant vertex…

Weak current-induced baryonic form factors at zero recoil are evaluated in the rest frame of the heavy parent baryon using the nonrelativistic quark model. Contrary to previous similar work in the literature, our quark model results do…

Light flavour baryons are studied in a non-relativistic potential model with colour Coulomb plus linear confinement potential using a simple variational method. The ground-state masses and magnetic moments of the light baryons are computed…

We perform a calculation of the relativistic corrections to the electromagnetic elastic form factors of the nucleon obtained with various Constituent Quark Models. With respect to the non relativistic calculations a substantial improvement…

The second excitation of the nucleon, the Roper, has properties differentiated from other low-lying nucleon resonances. Their properties challenge our understanding of the structure of the baryons in terms of the degrees of freedom from…

Semileptonic decays of bottom and charm baryons are considered within a relativistic three-quark model with the Gaussian shape for the baryon-three-quark vertex and standard quark propagators.

We reconsider baryon stopping in relativistic heavy-ion collisions in a nonequilibrium-statistical framework. The approach combines earlier formulations based on quantum chromodynamics with a relativistic diffusion model through a suitably…

Assuming Majorana nature of neutrinos, we re-investigate, in the light of the recent measurement of the reactor mixing angle, the allowed ranges for the absolute values of the elements of the neutrino mass matrix in the basis where the…

Longitudinal and transverse transition form factors for most of the four-star nucleon resonances have been obtained from high-quality cross section data and polarization observables measured at MAMI, ELSA, BATES, GRAAL and CEBAF. As an…

The rho-meson eletromagnetic form factors are calculated, both in covariant and light-front framework with constituintes quarks. The effect of the breakdown rotational symmetry for the one-body current operador in the null-plane is…

The baryon axial currents are calculated at one-loop order in heavy baryon chiral perturbation theory by employing both a cutoff and dimensional regularization. Data from the semileptonic baryon decays is used to perform a least-squares fit…

The multirank separable kernels of the neutron-proton interaction for uncoupled $S$ and $P$ partial waves (with the total angular momentum $J$=0,1) are proposed. Two different methods of a relativistic generalization of initially…

We discuss recent calculations of the mass spectrum, electromagnetic and strong couplings of baryon resonances. The calculations are done in a collective constituent model for the nucleon, in which the resonances are interpreted as…

Mass spectra of baryons consisting of two heavy (b or c) and one light quarks are calculated in the framework of the relativistic quark model. The light quark-heavy diquark structure of the baryon is assumed. Under this assumption the…

The exact solutions of the complete (1+3)-dimensional Dirac equation of fermions moving in ideal Aharonov-Bohm (AB) rings and cylinders are used for deriving the exact expressions of the relativistic partial currents. It is shown that these…

In quark potential models, two--body current contributions to baryon magnetic moments arise necessarily to satisfy the continuity equation for the electromagnetic current. On the other hand, the naive additive quark model predicts the…

Numerical calculations are performed and compared to the experimental data for the electromagnetic form factor of the kaon, which is extracted from both components of the electromagnetic current, $J^{+}$ and $J^{-}$, with a pseudo-scalar…

We investigate relativistic corrections of order $1/m^{2}$, where $m$ is the constituent quark mass, to heavy baryon decays by emitting one pseudoscalar meson in the quark model. This work is motivated by shortcomings in the previous…

The effects of the exchanges of both pseudoscalar and vector mesons among constituent quarks on the mass spectra of light baryons are investigated, paying particular attention to the contribution of tensor and spin-orbit terms. It is shown…

The light-front dynamics is an efficient approach to study of field theory and of relativistic composite systems (nuclei at relativistic relative nucleon momenta, hadrons in the quark models). The explicitly covariant version of this…