Unitarity Method with Spurious Pole
Abstract
Description
In unitarity cut method, compact input of on-shell tree level amplitudes is crucial to simplify calculations. Although BCFW on-shell recursion relation gives very compact tree level amplitudes, they usually contain spurious poles. In this paper, we present a method to deal with this issue and provide explicit simple algebraic functions for various coefficients in the presence of spurious poles. As an application, we present analytic result (not just rational term) for one-loop five gluon A(-++++) with scalar propagator for the first time.
49 pages; typos corrected, reference added; figures added, final version to appear in NPB
49 pages; typos corrected, reference added; figures added, final version to appear in NPB