Related papers: Renormalization group analysis of the tau-lepton d…
We study the renormalization group behaviour of the topological charge density in full QCD on the lattice. We propose a way of extracting the necessary renormalization functions from Monte Carlo simulations.
A systematic method is proposed for analyzing the renormalization scheme uncertainties in the next-next-to-leading order QCD predicitions, based on a condition which eliminates schemes that give rise to large cancellations in the expression…
QCD corrections to order alpha_s in the soft-gluon approximation to angular distributions of decay charged leptons in the process e+e- -> t tbar followed by semileptonic decay of t or tbar, are obtained in the e+e- centre-of-mass frame. As…
Recent theoretical results in tau lepton physics and their implications for the experimental analysis are presented. The paper is split into the following chapters: 1. Introduction, 2. Weak Couplings, 3. Inclusive Decays, Perturbative QCD…
Nonperturbative corrections up to $m_b^{-2}$ to the heavy lepton energy distributions are investigated in the inclusive semileptonic weak decays of heavy flavors in QCD. In the case of $B$-meson decays, for $b \ra u\tau\bnu$ transitions…
Precise measurements of the tau lepton properties provide stringent tests of the Standard Model structure and accurate determinations of its parameters. We overview the present status of a few selected topics: lepton universality, QCD tests…
Analytic continuation of the perturbative series from spacelike to timelike regions is performed using renormalization group summed perturbation theory (RGSPT). This method provides an all-order summation of kinematic ``$\pi^2$-terms''…
The charged lepton spectrum in semileptonic $B\to X_u \ell\bar\nu$ decay near maximal lepton energy receives important corrections from subleading structure functions that are formally suppressed by powers of $\Lambda_{QCD}/m_b$ but are…
We analyze the tauonic semileptonic baryon decays $\Lambda^0_b \to \Lambda^+_c + \tau^{-} +\bar \nu_{\tau}$ with particular emphasis on the lepton helicity flip contributions which vanish for zero lepton masses. We calculate the total rate,…
The QCD coupling, $\alpha_s$, is not a physical observable since it depends on conventions related to the renormalization procedure. Here we discuss a redefinition of the coupling where changes of scheme are parametrised by a single…
We compute the supersymmetric QCD corrections to the decay distribution of polarized top quarks for the semileptonic decay mode $t(\uparrow)\to b l^+\nu_l$. As a byproduct, we reinvestigate the SUSY-QCD corrections to the total decay width…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to b \to c l \bar \nu_l decay rate at a fully differential level. Arbitrary cuts on kinematic variables of the decay products can be imposed. Our computation can be used to…
We develop the perturbative QCD formalism for inclusive semileptonic $B$ meson decays, which includes Sudakov suppression from the resummation of large radiative corrections near the high end of charged lepton energy. Transverse degrees of…
The full treatment, both nonperturbative - through O(1/m_c^3) - and perturbative - through O(alpha_s) and BLM type O(alpha_s^2) - of the semileptonic lifetime of the D meson is given. A dedicated discussion of the numerics involved is made,…
Semileptonic decays of $B$ mesons to the tau lepton, despite of experimental difficulties, are of great importance. In particular they are sensitive probes of models with extended Higgs sectors. The results of studies of semitauonic B…
The general features of renormalization and the renormalization group in QED and in general quantum field theories in curved spacetime with additional Lorentz- and CPT-violating background fields are reviewed.
With the development of lattice QCD in recent years, a determination of decay rates for inclusive semileptonic decays from lattice correlators now seems viable. We report on the calculation of the inclusive semileptonic decay of the $D_s$…
Based on the Renormalization Group method, a reduction of non integrable multi-dimensional hamiltonian systems has been performed. The evolution equations for the slowly varying part of the angle-averaged phase space density, and for the…
The polarization effects in the one-meson radiative decay of the polarized $\tau$ lepton, $\tau^-\to\pi^-\gamma\nu_{\tau}$, have been investigated. We present the analytical results for the $t-$distribution of the partial differential…
We present the results of a first-principles theoretical study of the inclusive semileptonic decays of the $D_{s}$ meson. We performed a state-of-the-art lattice QCD calculation by taking into account all sources of systematic errors. A…