Related papers: Beyond the Narrow-Width Limit for Off-Shell and Bo…
We carry out a comprehensive analysis of the full set of $\bar{B}_q \to D_q^{(*)}$ form factors for spectator quarks $q=u,d,s$ within the framework of the Heavy-Quark Expansion (HQE) to order $\mathcal{O}(\alpha_s, 1/m_b, 1/m_c^2)$. In…
We compute the one-loop supersymmetric QCD quantum effects on the width $\Gamma (t\rightarrow W^{+}\, b)$ of the canonical main decay of the top quark within the framework of the MSSM. The corrections can be of either sign depending on…
The importance of off-shell contributions is discussed for $H\to VV^{(*)}$ with $V\in\{Z,W\}$ for large invariant masses $m_{VV}$ involving a standard model (SM)-like Higgs boson with $m_H=125$GeV at a linear collider (LC). Both dominant…
We discuss a model-independent framework for the analysis of the radiative B-meson decays B -> K* gamma and B -> rho gamma based on the heavy-quark limit of QCD. We present a factorization formula for the treatment of B -> V gamma matrix…
Two body decays of charm mesons are studied by describing their amplitude in terms of a sum of factorizable and non-factorizable ones. The former is estimated by using a naive factorization while the latter is calculated by using a hard…
The top-quark system as a probe for new physics is considered using a consistent, gauge-invariant effective Lagrangian approach. The magnitude of new effects is estimated and the results are applied to top production through W fusion. Other…
The `optimal' factorization scale $\mu_0$ is calculated for open heavy quark production. We find that the optimal value is $\mu_F=\mu_0\simeq 0.85\sqrt{p^2_T+m_Q^2} $; a choice which allows us to resum the double-logarithmic,…
The calculation of $t\bar{t}Z$ production including leptonic decays of both $Z$ boson and top quarks via a partially or fully off-shell calculation represents a definite step forward towards a more accurate description of events whose…
We study single-particle inclusive (1PI) distributions in top-quark pair production at hadron colliders, working in the highly boosted regime where the top-quark p_T is much larger than its mass. In particular, we derive a novel…
Spin correlations in the t-channel single top quark production and its subsequent decay are investigated for the case of contributions involving anomalous Wtb couplings. We obtain analytical expressions for the differential widths for the…
Details of the two-loop analysis of long-distance QED radiative corrections to neutron beta decay are presented. Explicit expressions are given for hard, jet, and soft functions appearing in the factorization formula that describes the…
In the framework of the collinear factorized pQCD approach we calculate the small-$x_B$ process-dependent nuclear modification to the structure functions measured in neutrino-nucleus deeply inelastic scattering. We include both heavy quark…
The nonzero widths of heavy particles become significant when they appear in the final state of any decay occurring just around its kinematical threshold. To take into account such effects, a procedure, called the convolution method, was…
The constituent picture of hadrons implies certain quantum mechanical inequalities which must hold in the potential models. Basing on this qualitative consideration I argue that it is not easy to increase significantly the scale of the…
Calculations of radiative corrections to the top quark width are reviewed. QCD effects are discussed for $t-\bar t$ systems produced in $e^+e^-$ annihilation near the energy threshold.}
A study of hadron pair production mechanism is motivated by the recent observed decays $\bar B^0\to D^{(*)+}K^-K^0$. One novel phenomenon is threshold enhancement of the kaon pair production. We show that these decays in the heavy quark…
Multiple scattering, induced radiative energy loss and modified fragmentation functions of a heavy quark in nuclear matter are studied within the framework of generalized factorization in perturbative QCD. Modified heavy quark fragmentation…
The decay of a light Higgs boson to bottom quarks is dominant and can be exploited for the discovery of the Higgs particle and the measurement of its properties at the LHC and future collider experiments. We perform a first computation of…
Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_H< 2M_W, are briefly reviewed. The effects of higher order perturbative QCD (up to alpha_s^4-level) and QED…
Emission processes including $\alpha$-decay, heavy cluster decays, proton and di-proton emission are analyzed in terms of the well known factorisation between the penetrability and reduced width. By using a shifted harmonic oscilator plus…