Related papers: Two-loop corrections to the Isgur-Wise function in…
The brief review of the current status of the studies of the effects of the higher-order perturbative QCD corrections to the deep-inelastic sum rules is presented.
We compute squared matrix elements at next-to-next-to-leading order in perturbative quantum chromodynamics for the production of two or three (on- or off-shell) photons mediated via (light or heavy) quark loops. Our method handles all cases…
In this thesis, we develop resummation algorithms suitable for perturbative QCD. In the first part, we propose a resummation technique applicable to the Regge limit. We develop a new systematic procedure for this limit in perturbative QCD…
We present the analytic evaluation of the second-order corrections to the massive form factors, due to two-loop vertex diagrams with a vacuum polarization insertion, with exact dependence on the external and internal fermion masses, and on…
In this paper we compute the QCD corrections for the triple Higgs boson production cross section via gluon fusion, within the heavy-top approximation. We present, for the first time, analytical results for the next-to-leading order…
We consider correlation functions containing the axial current of one light and one heavy quark in the static approximation as well as in full QCD, using the lattice regularization. Up to one-loop order of perturbation theory, we study the…
The computation of one-loop corrections to the $\gamma^\star Q_+ q$ and $gR_+g$ effective vertices in the framework of gauge-invariant effective theory for Multi-Regge processes in QCD is reviewed. Due to consistent implementation of the…
We present preliminary results from simulations done on 170 $32^3 \times 64$ lattices at $\beta = 6.0$ using quenched Wilson fermions. This talk focuses on the $Q^2$ behavior of the form-factors, extrapolation in quark masses, dependence on…
We compute the two-loop mixed QCD-Electroweak (QCD-EW) corrections to the production of a Higgs boson and a gluon in gluon fusion. The relevant four-point functions with internal massive propagators are expressed as multiple polylogarithms…
We review algorithmic methods for two-loop calculations in HQET, and the analogous methods for on-shell QCD, needed for matching HQET to QCD.
The Lambda_b to Lambda_c semileptonic decay is analyzed in the framework of heavy quark effective theory to the order of 1/m_c and 1/m_b. The QCD sum rule and large N_c predictions to the decay form factors are applied. It argues that the…
We study heavy light mesons in a QCD inspired quark model with the Cornell potential$-\frac{4\alpha_{S}}{3r}+br+c$. Here we consider the linear term $br$ as the parent and $-\frac{4\alpha_{S}}{3r}+c$ i.e.the Coloumbic part as the…
We calculate the Isgur-Wise function on the lattice, simulating the light quark with the Wilson action and the heavy quark with a direct lattice implementation of the heavy-quark effective theory. Improved smearing functions produced by a…
We present the two-loop virtual QCD corrections to the scattering of massless identical quarks, q qbar to q qbar, in conventional dimensional regularisation and using the MSbar scheme. The structure of the infrared divergences agrees with…
We compute the two-loop massless QCD corrections to the amplitude of Higgs boson decay to bottom quark pair and a gluon ($H \rightarrow b + \bar{b} + g$) in the higher powers of the dimensional regularization parameter $\epsilon$. The…
Although the methods of calculation of power corrections in QCD sum rules are well known, algebraic complexity rapidly grows with the increase of vacuum condensates' dimensions. Currently, state-of-the-art calculations include dimension 7…
In Heavy Quark Effective Theory the calculation of form-factors of higher excited states in a non-relativistic framework suffers severe inconsistencies due to frame dependencies. We show how careful inclusion of the Wigner-rotation of the…
In the asymptotic limit $Q^2 \gg m^2$, the heavy quark form factors exhibit Sudakov behavior. We study the corresponding renormalization group equations of the heavy quark form factors which do not only govern the structure of infrared…
Numerical Stochastic Perturbation Theory was able to get three- (and even four-) loop results for finite Lattice QCD renormalization constants. More recently, a conceptual and technical framework has been devised to tame finite size…
Recent results for higher-order corrections to the relation between the vector-boson masses in the Standard Model and Supersymmetry are summarized. In the Standard Model, the Higgs-mass dependence of the two-loop contributions to Delta r is…