Related papers: Heavy top renormalon contribution to fermion propa…
Top-quark physics is one of the main fields of investigation at the Tevatron accelerator and, ultimately, at the LHC. We perform a phenomenological analysis of ttbar events at hadron colliders, with a focus on observables relying on…
We present a comprehensive analysis of the Landau-Khalatnikov-Fradkin transformations for the charged fermion propagator in reduced quantum electrodynamics (RQED). Starting from the propagator in a reference gauge, we perform a gauge…
It is shown that wave function renormalization can introduce an important contribution to the generation of baryon and lepton number asymmetries by heavy particle decay. These terms, omitted in previous analyses, are of the same order of…
Using non-perturbative techniques we have found the renormalisation factor, Z, in the RI-MOM scheme for quark bilinear operators in quenched QCD. We worked with overlap fermions using the Luescher-Weisz gauge action. Our calculation was…
We demonstrate that the leading IR-renormalon divergence in the perturbative pole mass of a massive quark resides entirely in the contribution from the trace anomaly of the energy-momentum tensor in QCD. Consequently, the recently proposed…
We report on simulation results with overlap hypercube fermions (overlap HF) - a type of exactly chiral lattice fermions - and their link to chiral perturbation theory. We first sketch the construction of the overlap HF and discuss its high…
We study soft-gluon radiation in top quark decay within the framework of perturbative fragmentation functions. We present results for the b-quark energy distribution, accounting for soft-gluon resummation in both the MSbar coefficient…
In this thesis we study the b-quark fragmentation in top decay as well as the effect of the threshold resummation on heavy quark production in charged-current DIS. To predict the spectrum of b-flavored hadrons in top decay, we calculate at…
The properties of scalar quarks are studied, especially the formation of fermionic mesons with an anti-quark. On the basis of this theoretical investigation together with the experimental data, both from last year and from this year, of the…
We propose that the non-perturbative fragmentation functions describing the transition from a heavy quark to a heavy meson is proportional to the square of the produced meson wave function at the origin. We analyze the effects of this…
We discuss a method for calculating the heavy quark vacuum polarisation contribution to the muon anomalous magnetic moment, $a_\mu$, using perturbative QCD. This approach is independent of $e^+e^-$ cross-section data allowing a fully…
We present the threshold resummation for the cross section for electroproduction of heavy quarks. We work to next-to-leading logarithmic accuracy, and in single-particle inclusive kinematics. We provide next-to-leading and…
The current status of electroweak radiative corrections to the muon anomalous magnetic moment is discussed. Asymptotic expansions for some important electroweak two loop top quark triangle diagrams are illustrated and extended to higher…
The fragmentation function of a scalar leptoquark into possible S-wave bound states with a heavy anti-quark is calculated to the leading order in perturbative QCD for the high energy processes at large transverse momenta. The one-loop…
We study the behavior of dynamically-generated baryon resonances with heavy-quark content within a unitarized coupled-channel theory in matter that fulfills heavy-quark spin symmetry constraints. We analyze the implications for the…
We present new results for QCD corrections to the top-pair invariant mass and top-quark $p_T$ distributions in boosted top-quark pair production at hadron colliders. They are derived from a formalism which allows the joint resummation of…
I present an overview of standard-model top-quark physics at the Fermilab Tevatron. Topics discussed include the top-quark mass, weak interaction, strong interaction, and rare decays.
Recent calculations are presented of top quark polarization in $t\bar t$ pair production close to threshold. S-P-wave interference gives contributions to all components of the top quark polarization vector. Rescattering of the decay…
The potential of a static quark-antiquark pair is studied in the range 0.05 fm $<$ r $<$ 0.8 fm, employing a sequence of lattices up to 64^4. The continuum quantities are evaluated by extrapolation of the data at finite lattice spacing. The…
A certain pattern of divergence of perturbative expansions in quantum field theories, related to their small and large momentum behaviour, is known as renormalons. We review formal and phenomenological aspects of renormalon divergence. We…