Work

Bhabha scattering at NNLO with next-to-soft stabilisation

Year: 2021

Type: article

Abstract: A critical subject in fully differential QED calculations originates from numerical instabilities due to small fermion masses that act as regulators of collinear singularities. At next-to-next-to-leading order (NNLO) a major challenge is therefore to find a stable implementation of numerically delicate real-virtual matrix elements. In the case of Bhabha scattering this has so far prevented the development of a fixed-order Monte Carlo at NNLO accuracy. In this paper we present a new method for stabilising the real-virtual matrix element. It is based on the expansion for soft photon energies including the non-universal subleading term calculated with the method of regions. We have applied this method to Bhabha scattering to obtain a stable and efficient implementation within the McMule framework. We therefore present for the first time fully differential results for the photonic NNLO corrections to Bhabha scattering.

Source: Physics Letters B

DOI: 10.1016/j.physletb.2021.136547

Authors: Pulak Banerjee, Tim Engel, Nicolas Schalch, Adrian Signer, Yannick Ulrich

Institutions: Paul Scherrer Institute, University of Zurich, University of Bern, Durham University

Language: English

Topic: Particle physics theoretical and experimental studies

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond