Abstract
We derive a new non-singular tree-level KLT relation for the
n
= 5-point amplitudes, with manifest 2(
n
− 2)! symmetry, using information from one-loop amplitudes and IR divergences, and speculate how one might extend it to higher n-point functions. We show that the subleading-color
SYM 5-point amplitude has leading IR divergence of 1/
ϵ
, which is essential for the applications of this paper. We also propose a relation between the subleading-color
SYM and
supergravity 1-loop 5-point amplitudes, valid for the IR divergences and possibly for the whole amplitudes, using techniques similar to those used in our derivation of the new KLT relation.