Top tree amplitudes for higher order calculations

Abstract

Abstract We present compact analytic results for tree-level amplitudes containing a $$ t\overline{t} $$ t t ¯ pair accompanied by up to four massless partons, $$ t\overline{t} gg $$ t t ¯ gg , $$ t\overline{t} ggg $$ t t ¯ ggg , $$ t\overline{t} gggg $$ t t ¯ gggg , $$ t\overline{t}q\overline{q} $$ t t ¯ q q ¯ , $$ t\overline{t}q\overline{q}g $$ t t ¯ q q ¯ g , $$ t\overline{t}q\overline{q} gg $$ t t ¯ q q ¯ gg and $$ t\overline{t}q\overline{q}{q}^{\prime }{\overline{q}}^{\prime } $$ t t ¯ q q ¯ q ′ 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 $$ t\overline{t} $$ t t ¯ pair and zero, one, or two light parton jets, with the option to include the tree-level decays t → bνe+ and $$ \overline{t} $$ t ¯ → $$ \overline{b}e $$ b ¯ e −$$ \overline{\nu} $$ ν ¯ efficiently. Our results are part of the NNLO corrections to $$ t\overline{t} $$ t t ¯ production including the decay correlations for on-shell top quarks.