Twistor-inspired construction of massive quark amplitudes

TL;DR

This paper develops a twistor-inspired method for calculating scattering amplitudes involving massive quarks, extending previous scalar-based approaches and making supersymmetric relations explicit.

Contribution

It introduces a new set of rules for massive quark amplitudes derived from twistor-inspired techniques, including a wave-function prescription and multi-flavor extension.

Findings

Derived rules for massive quark amplitudes

Explicit relations between quark and scalar amplitudes

Extended formalism to multiple quark flavors

Abstract

The analog of the Cachazo-Svrvcek-Witten rules for scattering amplitudes with massive quarks is derived following an approach previously employed for amplitudes with massive scalars. A prescription for the external wave-functions is given that leads to a one-to one relation between fields in the action and spin-states of massive quarks. Several examples for the application of the rules are given and the structure of some all-multiplicity amplitudes with a pair of massive quarks is discussed. The rules make supersymmetric relations to amplitudes with massive scalars manifest at the level of the action. The formalism is extended to several quark flavors with different masses.