Related papers: Angular Distributions of Massive Quarks and Lepton…
Angular and energy distributions for leptons and bottom quarks in the process e+e- --> t tbar --> l/b ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the…
We discuss production of charm and bottom quarks at forward rapidity in pp collisions at the LHC, updating the QCD predictions for the run at \sqrt{S}=13 TeV. We show that, while the absolute rates suffer from large theoretical systematics,…
I present new results and updates for total cross sections and differential distributions in top-antitop pair and single-top production. Soft-gluon corrections are added to exact fixed-order results to provide the best predictions at…
The parametric error on the QCD-coupling can be a dominant source of uncertainty in several important observables. One way to extract the coupling is to compare high order perturbative computations with lattice evaluated moments of heavy…
We calculate the Coulomb gauge temporal quark and gluon propagators in quenched QCD. From the temporal quark and gluon propagators, dispersion relations and quasiparticle masses are determined by means of the Maximum Entropy Method.
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $\gamma\gamma$ collisions. The results are relevant to heavy quark…
A physically defined QCD coupling parameter naturally incorporates massive quark flavor thresholds in a gauge invariant, renormalization scale independent and analytical way. In this paper we summarize recent results for the finite-mass…
The results of two methods to extract the strong coupling constant, $\alpha_s$, are reviewed for the LEP experiments. In the first, scaling violations in the scaled momentum distributions of charged particles at LEP and at lower energy…
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…
In the last decade a Quasi-Particle Model (QPM) has been developed to study charm quark dynamics in ultra-relativistic heavy-ion collisions supplying a satisfactory description of the main observables for $D$ meson and providing an estimate…
The one-loop weak-magnetic and weak-electric dipole form factors of heavy fermions in a generic model are derived. Numerical predictions for the $\tau$ lepton and $b$ quark Weak Anomalous Magnetic and Electric Dipole Moments (AWMDM and…
A new ansatz for quark and lepton mass matrices is proposed in the context of supersymmetric grand unified theories. The 13 parameters describing fermion masses and mixings are determined in terms of only 6 free parameters, allowing 7…
The threshold scan at future lepton colliders is the most precise known method to determine the top quark mass (well below 100 MeV), a fundamental parameter of the Standard Model that co-determines the stability properties of the…
We investigate medium effects in QCD like chromoelectric screening and quasi-particle mass generation by calculating the heavy quark potential as well as the temporal quark and gluon Coulomb gauge propagators in quenched approximation.
When a TeV-scale leptoquark has a sizeable Yukawa coupling, its dominant production mechanism at hadron colliders is the partonic-level lepton-quark fusion. Even though the parton distribution functions for leptons inside the proton are…
We study the angular distribution of the charged lepton in the top-quark decay into a bottom quark and a W boson which subsequently decays into \ell\nu_{\ell}, when a hard gluon is radiated off. The absorptive part of the t \to bWg decay…
The moments of the heavy quark-parton distribution functions in a heavy pseudoscalar meson are calculated from QCD sum rules. Expanding these sum rules in the inverse heavy quark mass we obtain the heavy-mass limits of the moments.…
We present a theory of the scaling behavior of the thermodynamic, transport and dynamical properties of a three-dimensional metal at an antiferromagnetic critical point. We show how the critical spin fluctuations at the AFM wavevector q=Q…
We investigate the effect of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the GUT scale within the large $\tan\beta$ regime of the MSSM. In addition to the typically dominant…
The structure function of a heavy quark in a heavy hadron in electroproduction is calculated from QCD. Its deviation from the parton model prediction (a delta function) is shown to be governed by a shape function, similar to the one…