1. Try to figure out QQ –> gg with spinor helicity formalism, check the helicity amplitude and amplitude squared
2. Try massless spinor helicity formalism for qq–>tt gamma
3. Try massless spinor helicity formalism for gg–>tt gamma
4. Try massive spinor helicity formalism for qq–>tt gamma
5. Try massive spinor helicity formalism for gg–>tt gamma
6. Study the Passarino Veltman reduction, look at virtual corrections….
