We introduce a new technique to generate scattering amplitudes at one loop. Traditional tree algorithms, which handle diagrams with fixed momenta, are promoted to generators of loop-momentum… (More)

Charged gauge boson pair production at the Large Hadron Collider allows detailed probes of the fundamental structure of electroweak interactions. We present precise theoretical predictions for… (More)

We construct approximate formulas for the O(αs) QCD contributions to vector, axial-vector, scalar and pseudo-scalar quark current correlators, which are valid for arbitrary values of momenta and… (More)

We describe several techniques for the calculation of multi-loop integrals and their application to heavy quark current correlators. As new results, we present the fourloop correction to the second… (More)

We present the first 30 moments of the low energy expansions of the vector, axialvector, scalar and pseudo-scalar heavy quark correlation functions at three-loop order, including the singlet… (More)

The four-loop QCD corrections to the electroweak rho parameter arising from top and bottom quark loops are computed. Specifically we evaluate the missing "nonsinglet" piece. Using algebraic methods… (More)

The second moment of the heavy quark vector correlator at O(αs) is presented. The implications of this result on recent determinations of the charm and bottom quark mass are discussed.

We present the result for the three-loop singlet QCD corrections to the decay of a Higgs boson into two photons and improve the calculation for the non-singlet case. With the new result presented,… (More)

where the bottom quark mass has been neglected, hence it is quadratic in the top-quark mass mt. The symbol GF denotes the Fermi coupling constant. The ρ-parameter enters in numerous physical… (More)