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32 lines
1.6 KiB
32 lines
1.6 KiB
\midheading{$Z+Q+$jet production, processes 341--357}
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\label{subsec:ZQj}
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These processes represent the production of a $Z$
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boson that decays into a pair of electrons,
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in association with a heavy quark, $Q$ and an untagged jet.
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For more details on this calculation, please see Ref.~\cite{Campbell:2005zv}.
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For processes {\tt 341} and {\tt 351} the initial state at lowest
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order is the heavy quark and a gluon and the calculation may be
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performed at NLO. Thus in these processes the quark $Q$ occurs as
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parton PDF in the initial state. As for $H+b$ and $Z+Q$ production,
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the matrix elements are divided into two sub-processes at NLO. Thus
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the user must sum over these after performing more runs than usual. At
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lowest order one can proceed as normal, using {\tt nproc=341} (for
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$Zbj$) or {\tt nproc=351} (for $Zcj$). For a NLO calculation, the
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sequence of runs is as follows:
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\begin{itemize}
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\item Run {\tt nproc=341} (or {\tt 351}) with {\tt part=virt} and
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{\tt part=real} (or, both at the same time using {\tt part=tota});
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\item Run {\tt nproc=342} (or {\tt 352}) with {\tt part=real}.
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\end{itemize}
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The sum of these yields the cross-section with one identified heavy
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quark and one untagged jet in the final state when {\tt inclusive} is
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set to {\tt .false.} . To calculate the rate for at least one heavy
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quark and one jet (the remaining jet may be a heavy quark, or
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untagged), {\tt inclusive} should be {\tt .true.}.
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Processes {\tt 346,347} and {\tt 356,357} are the lowest order processes that enter
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the above calculation in the real contribution. They can be computed only at LO.
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When {\tt removebr} is true, the $Z$ boson does not decay.
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