We show that because of the milder GIM suppression, the four-quark dipenguin operator contributes to the short distance piece of the D − D̄ mixing amplitude at the same order of magnitude as the box diagram. In addition, we put an upper bound ∆m D ≤ 5 ×∆mbox D on a long-distance resonant contribution induced by the penguin mixing. The phenomenon of meson mixing has been studied for a long time. ...

Quark model results for the B → π, ρ decays are analysed, making use of the dispersion formulation of the model: The form factors at q 2 > 0 are expressed as relativistic invariant double spectral representation over invariant masses of the initial and final mesons through their light–cone wave functions. The dependence of the results on the quark model parameters is studied. For various versio...

Quark model results for the B → π, ρ decays are analysed, making use of the dispersion formulation of the model: The form factors at q 2 > 0 are expressed as relativistic invariant double spectral representation over invariant masses of the initial and final mesons through their light–cone wave functions. The dependence of the results on the quark model parameters is studied. For various versio...

We consider a simple SU(2) quark soliton model based on chiral invariant quark-meson couplings. We nd axially symmetric, classically stable soliton solutions with B=2,3 and 4 (where B is the baryon number). The energy distributions corresponding to these solutions are toroidal in nature. The symmetries of the B=2 solution indicate that the ground state of this solution has the quantum numbers o...

We present the results of a quenched lattice QCD study of the coupling g, in the static heavy quark limit. After combining this with our previous results obtained by using propagating heavy quarks with a mass around the physical charm quark, we are able to interpolate to the b-quark sector. Our results are g ∞ = 0.48 ± 0.

A new method to extract |V bc | is proposed based on a sum–rule for semilep-tonic decays of the B meson. The method relies on much weaker assumptions than previous approaches which are based on heavy–quark symmetry. This sum–rule only relies on the assumption that the virtual cc pair content of the B meson can be neglected. The extraction of the CKM matrix element also requires that the sum–rul...

Light-cone QCD sum rules are employed to compute the strong coupling constants: gB∗B∗π, gB1B0π and gB1B∗π, where (B,B ∗) and (B0, B1) are negative and positive parity (0−, 1−) and (0+, 1+) q̄Q doublets. The couplings are calculated both for finite values of the heavy quark mass and in the infinite heavy quark mass limit, deriving sum rules for mQ → ∞. PACS:11.55.Hx,13.20.He

Possible anomalous couplings of the top-quark to on-shell photons and gluons are constrained by the recent results of the CLEO Collaboration on both inclusive and exclusive radiative B decays. We find that the process b → sγ can lead to reasonable bounds on both the anomalous electric and magnetic dipole moments of the top-quark, while essentially no limits are obtained on the corresponding chr...

I discuss heavy flavor production at hadronic facilities. I present total cross sections and differential distributions for top quark, bottom quark, and charm quark production at the Tevatron and LHC colliders, and at fixed-target experiments such as HERA-B. The calculations include complete next-to-leading order corrections as well as higher-order soft-gluon corrections which are important nea...

The minimal standard electroweak model yields approximately half the observed value of the KL-KS mass difference. Antisymmetric tensor fields incorporated into the standard model can provide the rest 0.5×(∆mLS)exp. The effective lepton–lepton, quark–lepton and quark–quark tensor interactions induced by the charged tensor particles are presented. Submitted to “Phys. Lett. B” E-mail: physfac2@bge...