arXiv subjects

A. H. Fariborz

Publications and source records attributed to A. H. Fariborz.

22 records · Page 2Linked to original sources

arXiv1996

Spinors in Weyl Geometry

We consider the wave equation for spinors in ${\cal D}$-dimensional Weyl geometry. By appropriately coupling the Weyl vector $ϕ_μ$ as well as the spin connection $ω_{μa b } $ to the spinor field, conformal invariance can be maintained. The one loop effective action generated by the coupling of the spinor field to an external gravitational field is computed in two dimensions. It is found to be identical to the effective action for the case of a scalar field propagating in two dimensions.

hep-th↗

arXiv1996

Effective Higgs-to-Light-Quark Coupling Induced by Heavy Quark Loops

We study the coupling arising via perturbative QCD of zero 4-momentum Higgs bosons to light quarks inside the nucleon. Qualitative comparison with the results obtained from one-loop-order low energy theorems for the Higgs-nucleon interaction suggests the existence of a dynamical light-quark mass which falls off with momentum. Quantitative comparison leads to an estimate of $α_s$ at very low $q^2$ quite near unity.

hep-ph↗

arXiv1996

Induced Light-Quark Yukawa Couplings as a probe of Low-Energy Dynamics in QCD

We examine the heavy-quark-induced Yukawa interaction between light quarks and a light Higgs field, which is facilitated in the chiral limit by the dynamical mass of light quarks anticipated from the chiral-noninvariance of the QCD vacuum. A low-energy estimate of the strong coupling near unity can be obtained from a comparison of the explicit perturbative calculation of the induced Yukawa interaction at zero momentum to a Higgs-low-energy theorem prediction for the same interaction.

hep-ph↗

arXiv1995

Estimates of B-decays into K-Resonances and Dileptons

Short and long distance contributions to the exclusive B-decays into various K-resonances and dileptons, i.e. B --> Ki l l ( l = e, mu , nu ), are examined. The heavy quark effective theory has been used to calculate the hadronic matrix elements. Substantial branching fractions are obtained for the dileptonic B-decays into some higher excited states of K-mesons. The long distance (resonance) contributions to these exclusive rare B-decay modes dominate the short distance contributions mostly by two orders of magnitude. It is pointed out that, excluding the resonance contributions, the P-wave channels are dominant, accounting for about 50% of the inclusive B --> X_s l l branching fraction.

hep-ph↗