BCFW tree level QCD corrections to WBF Higgs production

Abstract

We explicitly compute analytic tree level amplitudes for the production of a Higgs boson via Weak Boson Fusion (WBF) with one and two additional gluon emissions in the final state. Also, the computation for the additional emission of an arbitrary number of gluons is discussed, obtaining a general result related to the procedure of contraction of 2 Single Weak Boson (SWB) currents which are precisely characterized. The generalization of the Britto-Cachazo-Feng-Witten (BCFW) formula to the massive case is applied obtaining compact results which agree with those calculated with the conventional approach of Feynman diagrams. We show that, in relation to the latter method, the involved BCFW amplitudes are computed through a notably more efficient process (particularly for high numbers of external particles) suggesting that successive corrections to the WBF process can be obtained alike in a swift way. The explicit expressions are provided in a parallel presentation of both approaches, putting the emphasis on the fundamental features and advantages of the BCFW scheme.