Automated Calculation and Simulation Systems

I briefly summarize the parallel sessions on Automated Calculation and Simulation Systems for high energy particle physics phenomenology at ACAT 2002 (Moscow State University, June 2002) and present a short overview over the current status of the field and try to identify the important trends.Comment: 4 pages, LaTeX, to appear in the proceedings of ACAT 200

Top Quark Production at Hadron Colliders: an Overview

The study of the properties of the top quark is one of the main goals of the Large Hadron Collider (LHC) physics program. The experimental precision expected at the LHC requires the calculation of several top-quark related observables beyond leading order in the strong coupling constant. In this work we briefly review the status of the theoretical predictions for the top-quark production processes at hadron colliders. Special attention is devoted to recent progress in the calculation of next-to-next-to-leading-order corrections to the top-quark pair production cross section.Comment: Submitted to the proceedings of "The 2009 Europhysics Conference on High Energy Physics", July 16 - 22, 2009, Krakow, Poland. References adde

Topics in Electroweak Physics

We briefly discuss five topics in Precision Electroweak Physics: i) the recently proposed Effective Scheme of Renormalization, ii) evidence for electroweak bosonic corrections derived from the radiative correction Delta_r_eff, iii) an approach to estimate the scale of new physics in a hypothetical Higgs-less scenario, iv) simple and accurate formulae for s^2_eff, M_W, Gamma_l, and their physical applications, v) a recent proposal concerning the field renormalization constant for unstable particles.Comment: 5 pages, talk presented at the International Symposium Radcor 2002, September 8-13, Kloster Banz, German

Two-Loop QED Heavy-Flavor Contribution to Bhabha Scattering

We briefly review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. In particular, we focus on the analytic calculation of the two-loop virtual corrections involving a heavy-flavor fermion loop, which was recently completed. We conclude by assessing the numerical impact of these corrections on the Bhabha scattering cross section at colliders operating at a center of mass energy of 1 GeV and at the future ILC.Comment: 6 pages, 2 figures. Contribution to the Proceedings of the 9th DESY workshop on "Loops and Legs in Quantum Field Theory", Sondershausen, April 2008. References adde

Search for fermiophobic Higgs bosons in final states with photons at LEP 2

Higgs boson production with subsequent decay to photons was searched for in the data collected by the DELPHI detector at centre-of-mass energies between 183 GeV and 209 GeV, corresponding to a total integrated luminosity of nearly 650 pb^{-1}. No evidence for a signal was found, and limits were set on h0Z0 and h0A0 production with h0 decay to photons. These results were used to exclude regions in the parameter space of fermiophobic scenarios of Two Higgs Doublet Models.Comment: 24 pages, 6 figures, Accepted by Eur. Phys. J.

Master Integrals for double real radiation emission in heavy-to-light quark decay

We evaluate analytically the master integrals for double real radiation emission in the b --> u W* decay, where b and u are a massive and massless quark, respectively, while W* is an off-shell charged weak boson. Since the W boson can subsequently decay in a lepton anti-neutrino pair, the results of the present paper constitute a further step toward a fully analytic computation of differential distributions for the semileptonic decay of a b quark at NNLO in QCD. The latter partonic process plays a crucial role in the study of inclusive semileptonic charmless decays of B mesons. Our results are expressed in terms of multiple polylogarithms of maximum weight four.Comment: 21 pages, 6 figures, 2 table