https://doi.org/10.1140/epjc/s10052-017-4774-0
Regular Article - Theoretical Physics
Nested soft-collinear subtractions in NNLO QCD computations
1
CERN, Theoretical Physics Department, Geneva, Switzerland
2
IPPP, Durham University, Durham, UK
3
Institute for Theoretical Particle Physics, KIT, Karlsruhe, Germany
* e-mail: fabrizio.caola@cern.ch
Received:
12
February
2017
Accepted:
19
March
2017
Published online:
18
April
2017
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 
gluonic corrections to the Drell–Yan process of 
annihilation into a lepton pair. We show that this framework leads to fast and numerically stable computation of QCD corrections.
© The Author(s), 2017
