Top tree amplitudes for higher order calculations
We present compact analytic results for tree-level amplitudes containing a $$t\bar{t}$$ pair accompanied by up to four massless partons $$t\bar{t}gg$$, $$t\bar{t}ggg$$, $$t\bar{t}gggg$$, $$t\bar{t}q\bar{q}$$, $$t\bar{t}q\bar{q}g$$, $$t\bar{t}q\bar{q}gg$$, and $$t\bar{t}q\bar{q}q'\bar{q'}$$. The results, obtained using BCFW on-shell recursion, are based both on previous published results and on the new calculations performed in this paper. These amplitudes are sufficient to calculate the production of a $$t\bar{t}$$ pair and zero, one, or two light parton jets, with the option to include the tree-level decays t → bνe+ and $$\bar{t} → \bar{b}e^-\bar{v}$$ efficiently. Our results are part of the NNLO corrections to $$t\bar{t}$$ production including the decaymore »