500 f(-p1) + f(-p2) W+(ν(p3) + e+(p4)) + t(p5) + t(p6), massive

500.1 W + tt processes 500–516

These processes represent the production of a W boson which subsequently decays leptonically, in association with a tt pair. In all except processes 500 and 510 the decays of the top and anti-top quark are included. Processes 501,502 and 511,512 refer to the semileptonic decay of the top and antitop quarks, with the latter process in each pair giving the radiation in the decay of the top and antitop. Process 503 (513) refers to the semileptonic decay of the top (antitop) and the hadronic decay of the antitop (top). Processes 506(516) gives the semileptonic decay of the antitop(top) and the hadronic decay of the top(antitop). Processes 506(516) do not give same sign lepton events, so they may be of less phenomenological importance. For this reason we have not yet included radiation in the decay for these processes.

For processes 503, 506, 513 and 516 the default behaviour is that the hadronic decay products are clustered into jets using the supplied jet algorithm parameters, but no cut is applied on the number of jets. This behaviour can be altered by changing the value of the variable notag in the file src/User/setnotag.f.

The top quarks are always produced on-shell, which is a necessity for a gauge invariant result from this limited set of diagrams, but all spin correlations are included. Switching zerowidth from .true. to .false. only affects the W bosons (both the directly produced one and from the top quark decay). Processes 501 and 511 may be run at NLO with the option todk, including radiation in the decay of the top quark, see section ??.

500.2 Plotter

nplotter_auto.f is the default plotting routine.

500.3 Example input and output file(s)

input500.ini process500.out