\midheading{$Ht$ and $H\bar{t}$ production, processes 540--557}

\label{subsec:Ht}
These processes describe the production of a single top quark ({\tt 540}, {\tt 544}, {\tt 550},
{\tt 554}) or antiquark ({\tt 541}, {\tt 547}, {\tt 551}, {\tt 557}) by $W$ exchange in the
$t$-channel, in association with a Higgs boson. These processes can be performed at NLO.
For processes {\tt 540}, {\tt 541}, {\tt 550},
{\tt 551}, the top quark does not decay, but the
Higgs boson decays to $b\bar{b}$, ({\tt 540}, {\tt 541}), or to $\gamma \gamma$, ({\tt 550}, {\tt 551}).
Processes {\tt 544}, {\tt 547} and {\tt 554}, {\tt 557} include the decay of the top quark and antiquark
in the approximation in which the top quark is taken to be on shell allowing a clean separation
between production and decay.
For more details on this calculation, please see Ref.~\cite{Campbell:2013yla}.

It is possible to study the effects of anomalous couplings of the Higgs boson to the top quark and $W$ bosons. These
are parametrized by $c_{t\bar{t}H} = g_{t\bar{t}H}/g_{t\bar{t}H}^{SM}$ and $c_{WWH} = g_{WWH}/g_{WWH}^{SM}$
respectively, so that $c_{t\bar{t}H}=c_{WWH}=1$ in the SM. Different couplings may be chosen by modifying the variables
{\tt cttH} and {\tt cWWH} in the \verb|anom_higgs| section of the input file.