d-dimensional unitarity cut method

• DOI: 10.1016/j.physletb.2006.12.022
• Publication Date: 2006-12-20T10:12:23Z
• Authors: Charalampos Anast...; Ruth Britto; Bo Feng; Zoltan Kunszt; Pierpaolo Mastrolia
• Keywords: Unitarity; Propagator; Massless particle; Pentagon

We develop a unitarity method to compute one-loop amplitudes with massless propagators in d=4−2ϵ dimensions. double cuts of the loop via decomposition into four-dimensional and −2ϵ-dimensional integration. The integration is performed using spinor or other efficient techniques. remaining integral −2ϵ dimensions cast terms bubble, triangle, box, pentagon master integrals dimensional shift identities. yields results valid for arbitrary values ϵ.