\midheading{$g(-p_1)+g(-p_2) \to  \gamma(p_3)+\gamma(p_4)+f(p_5)$}
Process {\tt 2861} represents the process
$gg \to \gamma\gamma g$ mediated by a loop of light quarks.
This process is calculable at leading order LO, O($\alpha_s^3$).

The calculation is described in Ref.~\cite{Campbell:2014yka}.