Top tree amplitudes for higher order calculations

Abstract

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 $t\bar{t}q\bar{q}{q}^{\prime }{\bar{q}}^{\prime }$. 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 $t\to b\nu e^{+}$ and $\bar{t}\to \bar{b}{e}^{-}\bar{\nu }$ efficiently. Our results are part of the NNLO corrections to $t\bar{t}$ production including the decay correlations for on-shell top quarks.

Comments: 38 pages, 2 figures, results available as ancillary files; v2 corrects Eq. (7.34) in TeX and ancillary files