5 papers · 1 filter
Multi-channel phase space with Feynman-diagram-gauge amplitudes
Kaoru Hagiwara, Junichi Kanzaki, Fabio Maltoni +2
Multi-channel phase space with a single Feynman diagram enhancement is a powerful tool for high-energy physics event generation if a diagram with a singular propagator dominates th…
Automatic generation of helicity amplitudes in Feynman-Diagram gauge
Kaoru Hagiwara, Junichi Kanzaki, Olivier Mattelaer +2
We develop a method to calculate helicity amplitudes of an arbitrary tree-level process in Feynman-Diagram (FD) gauge for an arbitrary gauge model with MadGraph5_aMC@NLO. We start…
Helicity amplitudes in light-cone and Feynman-diagram gauges
Junmou Chen, Kaoru Hagiwara, Junichi Kanzaki +2
Recently proposed Feynman-diagram (FD) gauge propagator for massless and massive gauge bosons is obtained from a light-cone (LC) gauge propagator, by choosing the gauge vector alon…
Helicity amplitudes without gauge cancellation for electroweak processes
Junmou Chen, Kaoru Hagiwara, Junichi Kanzaki +1
In the 5-component representation of weak bosons, the first four components make a Lorentz four vector, representing the transverse and longitudinal polarizations excluding the sca…
QED and QCD helicity amplitudes in parton-shower gauge
Kaoru Hagiwara, Junichi Kanzaki, Kentarou Mawatari
We introduce photon and gluon propagators in which the scalar polarization component is subtracted systematically by making use of the BRST invariance of the off-shell vector boson…