\midheading{$WH$ production, processes 91-100, 900}
\label{subsec:wh}

This process can be calculated at LO, NLO, and NNLO.
These processes represent the production of a $W$ boson which subsequently
decays leptonically, in association with a Standard Model Higgs boson that
decays into a tau pair ({\tt nproc=91, 96}),
decays into a $b$-quark pair ({\tt nproc=92, 97}),
a pair of photons ({\tt nproc=93, 98}),
or a pair of $W$-bosons ({\tt nproc=94, 99}),
a pair of $Z$ bosons ({\tt nproc=95, 100}).
Note that in the cases of Higgs decay to $W$,($Z$) pairs,
below the $W$,($Z$) pair threshold
one of the $W$,($Z$) bosons is virtual
and therefore one must set {\tt zerowidth=.false.}.
The calculation may be performed at NNLO for these processes.

Radiation from the bottom quarks in the decay, an NLO effect, is included in  ({\tt nproc=920, 970}).
\texttt{nproc=900} may be used to compute the sum over both W charges in
one run (with the decay products 3 and 4 representing lepton and antilepton
respectively). This sum is performed by adjustng the CKM matrix to allow both charges of the $W$ boson.

When {\tt removebr} is {\tt .true.}, neither the $W$ boson nor the Higgs decays.

For more information on this
process see refs.~\cite{Campbell:2016jau,Boughezal:2016wmq,Campbell:2022gdq}.
NLO calculations can be performed by subtraction, zero-jettiness
slicing and $q_T$-slicing.  NNLO calculations can be performed by
zero-jettiness slicing and $q_T$-slicing.