The calculation of the partial width rare t-quark decay into Upsilon-meson, W-boson and b-quark (t -> \Upsilon W b) is presented. branching ratio equals Br(t Upsilon = 1.3 * 10^{-5} that make possible searches for this $t$-quark at LHC.

A set of general relations between the spin-independent and spin-dependent potentials of heavy quark and anti-quark interactions are derived from reparameterization invariance in the Heavy Quark E ective Theory. It covers the Gromes relation and includes some new interesting relations which are useful in understanding the spin-independent and spin-dependent relativistic corrections to the leadi...

One loop corrections to the coupling of the reggeized gluon to quarks are calculated in QCD. Combining this result with the known corrections to the gluon-gluon-reggeon vertex, we check the self-consistency of the representation of the amplitudes with gluon quantum numbers and negative signature in the t-channel in terms of Regge pole contribution. 1. Introduction Since a long time it has been ...

The Heavy Quark Effective Theory provides a systematic method to estimate mixing angle of hadron states in heavy quark, such as the charm quark (c) and bottom (b). By using this method, baryons $\varXi_Q-\varXi_Q'$ can be estimated. It is found that between $\varXi_Q$ $\varXi_Q'$ given by $\theta_b = 4.51^{\circ} \pm 0.79 ^{\circ}$ for $Q b$ case $\theta_c 8.12^{\circ} 0.80 c$ case.

Independent multiple scattering (‘Landshoff’) contributions to proton-proton elastic scattering at wide angles are calculated in the quark-diquark model. Results confirm previous observations about the magnitude of these contributions. The use of the quark-diquark model extends the applicability of perturbative QCD calculations down to lower values of momentum transfer substantially. 12.38.Bx, ...

In the physical vacuum of QCD, the energy density of lightquark fields strongly coupled to slowly varying gluon fields can be negative. The states that drive this energy density lowest are condensates of pairs of quarks and antiquarks of nearly opposite momenta. These quark-antiquark condensates break chiral symmetry.

We assume that each valence quark in a nucleon is in a phenomenological modified harmonic oscillator potential of the form: ( l+yo) (ar +br+cr +dr ), where a, b, c and d are constants and ? is one of the Dirac matrices. Then by making use of a suitable ansatz, the Dirac equation has a very simple solution which is exact. We then have calculated the static properties of the nucleon in the ...

we assume that each valence quark in a nucleon is in a phenomenological modified harmonic oscillator potential of the form: ( l+yo) (ar +br+cr +dr ), where a, b, c and d are constants and ? is one of the dirac matrices. then by making use of a suitable ansatz, the dirac equation has a very simple solution which is exact. we then have calculated the static properties of the nucleon in the ground...