A general subtraction scheme, STRIPPER (SecToR Improved Phase sPacE for real
Radiation), is derived for the evaluation of next-to-next-to-leading order
(NNLO) QCD contributions from double-real radiation to processes with at least
two particles in the final state at leading order. The result is a Laurent
expansion in the parameter of dimensional regularization, the coefficients of
which should be evaluated by numerical Monte Carlo integration. The two main
ideas are a two-level decomposition of the phase space, the second one
factorizing the singular limits of amplitudes, and a suitable parameterization
of the kinematics allowing for derivation of subtraction and integrated
subtraction terms from eikonal factors and splitting functions without
non-trivial analytic integration.Comment: 14 pages, 3 figures, matches published version, includes new name for
the scheme, extended discussion of massless final states, and some new
reference
