\bottomheading{Scalar mediator, processes 802 and 822}
802~$ S\to({\chi}(p_3)+\bar{\chi}(p_4)) +f(p_5)$ [Scalar Mediator]  NLO \\
822~$S\to({\chi}(p_3)+\bar{\chi}(p_4)) +\gamma(p_5) $[Scalar Mediator]  NLO + F 

Processes 802 and 822 produce the 
mono-jet or mono-photon signature through the following scalar operator, 
\begin{eqnarray}
\mathcal{O}_S=\frac{\Delta(\overline{\chi}\chi)(\overline{q}q)}{\Lambda^2}~,
\end{eqnarray}
These processes are available at NLO and include the usual treatment
of photons. See for instance the $V\gamma$ processes ($\sim$ 300) in
this manual for more details on photon setup in MCFM. As discussed
above the code will calculate left and right-handed helicity
amplitudes and build the vector operators from $(L+R)$. Therefore you
should ensure that the Left and right-handed couplings are equal in
{\tt dm\_parameters.DAT}. For these processes $\Delta$ is fixed from
the value of {\tt [Yukawa Scalar Couplings] } if this is {\tt .true.}
then $\Delta=m_q/\Lambda$ else $\Delta=1$.