High Energy / Nuclear Theory / RIKEN seminars

[HET seminar] Mixed EW-QCD two-loop amplitudes for Drell-Yan dilepton production

by Andreas von Manteuffel (MSU)



Drell-Yan production of a charged lepton pair is a key process at the Large Hadron Collider. The region of large invariant mass region is of particular interest for new physics searches, which motivates precise theory predictions at energies well above the Z resonance. In this talk, I discuss our recent calculation of the mixed electroweak-QCD two-loop amplitudes for the process qq->l+l- as a further step in this direction. I  present the calculation in two different approaches, the ’t Hooft-Veltman-Breitenlohner-Maison (HVBM) gamma5 scheme and Kreimer's anticommuting gamma5 scheme, and discuss how one arrives at scheme-independent results. Solving the master integrals in terms of multiple polylogarithms of algebraic arguments, we obtain fully analytic results for the helicity amplitudes, which allow for fast and robust numerical evaluations in Monte-Carlo programs.