Recent Developments in Higher-Order Calculations: Hard Functions at NLO with GoSam

Abstract

In this presentation, we will focus on a recent applications of the GoSam 2.0 automated framework which goes beyond the official scope of this code, originally designed for one-loop fixed order calculations. In particular, we describe a customized version of GoSam that has been recently employed to study the production of a top-antitop pair in association with a vector boson or with the Higgs boson to next-to-next-to-leading logarithmic accuracy. In the context of these calculations, the modified version of GoSam was used to evaluate the NLO hard functions which are needed to carry out the resummation of soft gluon emission effects. We also briefly comment on the ongoing efforts to generalize integrand reduction and unitarity for higher order calculation, towards the goal of developing efficient alternative computational techniques for the evaluation of scattering amplitudes beyond one loop.

arXiv comment10 pages, 1 figure, to appear in the proceedings of The European Physical Society Conference on High Energy Physics, 5-12 July 2017, Venice, Italy

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