CP violation can be observed in B decays when a given process depends upon interference between two weak amplitudes which have different CP-violating phases. Since most weak decay diagrams have quark lines where each has a definite flavor label, neutral mesons which are flavor mixtures are particularly interesting. Different diagrams can contribute to the different flavor components of the meso...

We study the top quark decay to b quark and W boson in the NonCommutative Standard Model (NCSM). The lowest contribution to the decay comes from the terms quadratic in the matrix describing the noncommutative (NC) effects while the linear term is seen to identically vanish because of symmetry. The NC effects are found to be significant only for low values of the NC characteristic scale. PACS:11...

We review several results that have been obtained using lattice QCD with the staggered quark formulation. Our focus is on the quantities that have been calculated numerically with low statistical errors and have been extrapolated to the physical quark mass limit and continuum limit using staggered chiral perturbation theory. We limit our discussion to a brief introduction to staggered quarks, a...

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency is shown both at low and high orders. This method improves the behavior of the perturbation series for inclusive and exclusive decay rates, and the largest theoretical error in the predictions coming from the...

In this note radiative corrections to the total hadronic decay rate of the τ-lepton are studied employing perturbative QCD and the operator product expansion. We calculate quadratic quark mass corrections to the decay rate ration R τ to the order O(α 2 s m 2) and find that they contribute appreciably to the Cabbibo supressed decay modes of the τ-lepton. We also discuss corrections of mass dimen...

Exclusive decays of χcJ(J = 0, 2) into φφ are investigated in the framework of perturbative quantum chromodynamics(pQCD) and 3P0 quark pair creation model. The results show that these two mechanisms exhibit a quite different behavior in evaluating the decay width for the χc0 and χc2. In pQCD method with nonrelativistic(NR) approximation, while the calculated χc2 → φφ decay width is comparable w...

Using the QCD sum rule approach we investigate the vertex associated with the decay D0(0+) → D+π−, where the scalar meson D0(0+) is considered as a four-quark state (cd)(ūd̄). Although our results for the mass and partial decay width are smaller than the mass and the total decay width of the broad scalar meson D∗0 0 (2308) reported by BELLE Collaboration, we can not discard the possibility that ...

The cooling history of a quark star in the color superconductive phase is investigated. Here we specifically focus on the 2-flavour color (2SC) phase where novel process of photon generation via glueball (GLB) decay have been already investigated (Ouyed & Sannino 2001). The picture we present here can in principle be generalized to quark stars entering a superconductive phase where similar phot...

We consider decays of the lowest-lying radially excited baryons. Assuming a single-quark decay approximation , and negligible configuration mixing, we make model-independent predictions for the partial decay widths to final states with a single meson. Masses of unobserved states are predicted using an old mass formula rederived using large-Nc QCD. The momentum dependence of the one-body decay a...

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency is shown both at low and high orders. This method improves the behavior of the perturbation series for inclusive and exclusive decay rates, and the largest theoretical error in the predictions coming from the...