Top spin correlation has been shown to be nontrivial in hadronic top-quark pair production, and can be realized by the asymmetries of the decay products of the top quark and antiquark. We show in this work that the top spin correlation is a sensitive probe to the anomalous top-quark couplings beyond the standard model. Specifically, we look at the anomalous chromomagnetic and chromoelectric dip...

We calculate the part of the order αs correction to the semileptonic heavy quark decay rate proportional to the number of light quark flavors, and use our result to set the scale for evaluating the strong coupling in the order αs term according to the scheme of Brodsky, Lepage and Mackenzie. Expressing the decay rate in terms of the heavy quark pole mass mQ, we find the scale for the MS strong ...

We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic decay of the Λ b we find at the zero recoil point a violation of the heavy quark symmetry of more than 20%. We test the method by calculating the decay width of the semileptonic Λ c decay and obtain a reasonab...

Working in the framework of a nonrelativistic quark model we evaluate the spectra and semileptonic decay widths for the ground state of doubly heavy Ξ and Ω baryons. We solve the three-body problem using a variational ansatz made possible by the constraints imposed by heavy quark spin symmetry. In order to check the dependence of our results on the inter-quark interaction we have used five diff...

Top spin correlation has been shown to be nontrivial in hadronic top-pair production, and can be realized by the asymmetries of the decay products of the top quark and antiquark. We show in this work that the top spin correlation is a sensitive probe to the anomalous top-quark couplings beyond the standard model. Specifically, we look at the anomalous chromomagnetic and chromoelectric dipole mo...

Corrections of O(α 2 s) to the decay of the top quark into a W boson and a bottom quark are calculated. The method is based on an expansion of the top quark propa-gator for small external momentum, q, as compared to the top quark mass, M t. The physical point q 2 = M 2 t is reached through Padé approximations. The described method allows to take effects induced by a finite W boson mass into acc...

Corrections of O(α 2 s) to the decay of the top quark into a W boson and a bottom quark are calculated. The method is based on an expansion of the top quark propa-gator for small external momentum, q, as compared to the top quark mass, M t. The physical point q 2 = M 2 t is reached through Padé approximations. The described method allows to take effects induced by a finite W boson mass into acc...

Following our recent paper on the calculations of diffractive quark jet production at hadron colliders, we present here the calculations of gluon jet production at hadron colliders in the two-gluon exchange parameterization of the Pomeron model. We use the helicity amplitude method to calculate the cross section formula. We find that for the gluon jet production the diffractive process is relat...

Direct and indirect information on the top quark mass and its decay modes is reviewed. The theory of top production in hadron-and electron-positron-colliders is presented.

A comprehensive study indicates that equally likely sources for trimuon events in neutrino scattering are a) charged heavy lepton production (with decay to three muons) and b) simultaneous production of a neutral lepton (with decay to two muons) and a heavy quark (with decay to one muon). The sequential decay of a heavy quark to two muons is less likely. An intriguing model yielding simultaneou...