Helicity amplitudes for QCD with massive quarks

Understand

The novel massive spinor-helicity formalism of Arkani-Hamed, Huang and Huang provides an elegant way to calculate scattering amplitudes in quantum chromodynamics for arbitrary quark spin projections.

• In this note we compute two families of tree-level QCD amplitudes with one massive quark pair and n-2 gluons.
• The two cases include all gluons with identical helicity and one opposite-helicity gluon being color-adjacent to one of the quarks.
• Our results naturally incorporate the previously known amplitudes for both quark spins quantized along one of the gluonic momenta.