\midheading{$Z+b{\bar b}+$~jet production ($m_b=0$), process 54}
\label{subsec:zbbjetmassless}

This process represents the production of a $Z$ boson (and virtual photon)
which subsequently decays leptonically, in association
with a $b{\bar b}$ pair and an additional jet.
The effect of the bottom quark mass is neglected throughout
and the calculation may be performed at LO only.

When {\tt removebr} is true, the $Z$ boson does not decay.