Nested soft-collinear subtractions in NNLO QCD computations

Caola, Fabrizio; Melnikov, Kirill; Röntsch, Raoul

Abstract

We discuss a modification of the next-to-next-to-leading order (NNLO) subtraction scheme based on the residue-improved sector decomposition that reduces the number of double-real emission sectors from five to four. In particular, a sector where energies and angles of unresolved particles vanish in a correlated fashion is redundant and can be discarded. This simple observation allows us to formulate a transparent iterative subtraction procedure for double-real emission contributions, to demonstrate the cancellation of soft and collinear singularities in an explicit and (almost) process-independent way and to write the result of a NNLO calculation in terms of quantities that can be computed in four space-time dimensions. We illustrate this procedure explicitly in the simple case of O(α2s)O(αs2) gluonic corrections to the Drell–Yan process of qq¯qq¯ annihilation into a lepton pair. We show that this framework leads to fast and numerically stable computation of QCD corrections.

Citation

Caola, F., Melnikov, K., & Röntsch, R. (2017). Nested soft-collinear subtractions in NNLO QCD computations. The European Physical Journal C, 77(4), Article 248. https://doi.org/10.1140/epjc/s10052-017-4774-0

• Journal Article Type: Article
• Acceptance Date: Mar 19, 2017
• Online Publication Date: Apr 18, 2017
• Publication Date: Apr 18, 2017
• Deposit Date: Jul 13, 2017
• Publicly Available Date: Jul 13, 2017
• Journal: European Physical Journal C: Particles and Fields
• Print ISSN: 1434-6044
• Electronic ISSN: 1434-6052
• Publisher: SpringerOpen
• Peer Reviewed: Peer Reviewed
• Volume: 77
• Issue: 4
• Article Number: 248
• DOI: https://doi.org/10.1140/epjc/s10052-017-4774-0
• Public URL: https://durham-repository.worktribe.com/output/1374114