=== What are the default dynamic factorization and renormalization scales in !MadEvent? ===
Since v.4.2.17, there is a new default dynamical scale choice in run_card.dat file:
{{{
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
F = fixed_ren_scale ! if .true. use fixed ren scale
F = fixed_fac_scale ! if .true. use fixed fac scale
91.1880 = scale ! fixed ren scale
91.1880 = dsqrt_q2fact1 ! fixed fact scale for pdf1
91.1880 = dsqrt_q2fact2 ! fixed fact scale for pdf2
1 = scalefact ! scale factor for event-by-event scales
}}}
i.e., variable factorization and renormalization scales,set to the central mT^2^ scale after kT-clustering of the event.
For a single heavy particle, this corresponds to the M^2^+pT^2^,
for pair of heavy particles it is the geometric mean of M^2^+pT^2^ for each particle,
for massless particles it is the pT^2^ of the last pair after clustering.
If the last clustering is a t-channel colorless exchange (as, e.g., in WBF), the two fact. scales are set to the last mT^2^ values on either side.
These scales are overridden by scales defined in [http://bazaar.launchpad.net/~madteam/madgraph5/trunk/view/head:/Template/SubProcesses/setscales.f setscales.f], if they are returned as non-0.
See [wiki:FAQ-General-2 How do I implement my own renormalization/factorization scales in MadEvent ?] for information about how to implement your own scales in MadEvent.