On the massive two-loop corrections to Bhabha scattering

We overview the general status of higher order corrections to Bhabha scattering and review recent progress in the determination of the two-loop virtual corrections. Quite recently, they were derived from combining a massless calculation and contributions with electron sub-loops. For a massive calculation, the self-energy and vertex master integrals are known, while most of the two-loop boxes are not. We demonstrate with an example that a study of systems of differential equations, combined with Mellin-Barnes representations for single masters, might open a way for their systematic calculation.Comment: 8 pages, 2 figures, latex, Contribution to Proceedings of XXIX Conf. of Theoretical Physics: Matter to the Deepest, Ustron, Poland, 8-14 September 2005; preprint number adde

Automatized calculation of 2-fermion production with DIANA and aITALC

The family of two fermion final states is among the cleanest final states at the International Linear Collider (ILC) project. The package aITALC has been developed for a calculation of their production cross sections, and we present here benchmark numerical results in one loop approximation in the electroweak Standard Model. We are using packages like QGRAF, DIANA, FORM, LOOPTOOLS for intermediate steps.Comment: Contribution to the proceedings of the International Conference on Linear Colliders (LCWS 04), Paris, April 19-23, 2004. 5 pages, 1 figure, 5 table

Status of Electroweak Corrections to Top Pair Production

We review the status of electroweak radiative corrections to top-pair production at a Linear Collider well above the production threshold. We describe the Fortran package topfit and present numerical results at sqrt(s) = 500 GeV, 1 TeV, and 3 TeV.Comment: 6 pages, LaTex, 2 tables, 1 figure, talk presented by T.R. at the Int. Workshop on Linear Colliders (LCWS 2002), 26-30 Aug 2002, Jeju Island, Kore

Theoretical improvements for luminosity monitoring at low energies

A comparison of theoretical results on NNLO leptonic and hadronic corrections to Bhabha scattering with the Monte Carlo generator BabaYaga@NLO used at meson factories is given. Complete NLO virtual corrections to the $e^+e^- \to \mu^+ \mu^- \gamma$ process are discussed.Comment: 8 pages, 4 figs, presented by J.Gluza at Radcor 201

Elektroweak one-loop corrections for e^+e^- annihilation into t\bar{t} including hard bremsstrahlung

We present the complete electroweak one-loop corrections to top-pair production at a linear e^+e^- collider in the continuum region. Besides weak and photonic virtual corrections, real hard bremsstrahlung with simple realistic kinematical cuts is included. For the bremsstrahlung we advocate a semi-analytical approach with a high numerical accuracy. The virtual corrections are parametrized through six independent form factors, suitable for Monte-Carlo implementation. Alternatively, our numerical package topfit, a stand-alone code, can be utilized for the calculation of both differential and integrated cross sections as well as forward--backward asymmetries.Comment: 34 page