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#
# This MG5aMC script is for the validation of the GGVV implementation where
# one compares the one-loop squared amplitudes for the process g g > e+ e- e+ e-
# once computed with MadLoop and once with GGVV amp
#
# The code below must be run as:
#
# ./bin/mg5_aMC --mode=GGVV PLUGIN/GGVV/CrossCheck_GGVV_epemepem.mg5
#
# And it will generate the output for this process using GGVV form factors.
#
# Make sure to remove any existing old output
!rm -rf CrossCheck_GGVV_gg_epemepem
#
# Dynamic linking requires to have all GGVV dependencies (including PLUGIN/GGVV/ggvvamp-1.0)
# in your environment paths. If you can't have this for whathever reason, then comment the line below.
set_linking_mode dynamic
#
# This is the UFO model that contains the GGVV form factors "definition"
import model PLUGIN/GGVV/GGVV_UFO_model-crosscheck
#
# The setting of the coupling orders may look awkward, but this is just so that loops
# are not built on top of the Form Factors vertices GGWW GGZA GGZZ and GGAA.
# The option --loop_filter=n>3 is necessary to insure that none of the triangle topology
# is taken into account by MadGraph
# Notice that we use here 'virt=QCD' since we will use the Born ME as our one- or two-loop GGVV ME.
generate g g > e+ e- e+ e- [virt=QCD] QCD^2==2 GGWW^2<=1 GGZA^2<=1 GGZZ^2<=1 GGAA^2<=1 --loop_filter=n>3 @1001
output CrossCheck_GGVV_gg_epemepem
#
# The launch will not display the result but it will initialize the code, in particular
launch -f
#
# Running it manually as done below will actually show the resulting
# one-loop squared ME for the first PS point.
!cd CrossCheck_GGVV_gg_epemepem/SubProcesses/P1001_gg_epemepem && ./check
#
# The result should be (of course only the finite part matters):
#
# n E px py pz m
# 1 0.5000000E+03 0.0000000E+00 0.0000000E+00 0.5000000E+03 0.0000000E+00
# 2 0.5000000E+03 0.0000000E+00 0.0000000E+00 -0.5000000E+03 0.0000000E+00
# 3 0.8855133E+02 -0.2210069E+02 0.4008035E+02 -0.7580543E+02 0.3015783E-05
# 4 0.3283294E+03 -0.1038496E+03 -0.3019338E+03 0.7649492E+02 0.2132481E-05
# 5 0.1523581E+03 -0.1058810E+03 -0.9770964E+02 0.4954839E+02 0.2523185E-05
# 6 0.4307611E+03 0.2318313E+03 0.3595630E+03 -0.5023788E+02 0.1112166E-04
#
# Matrix element born = 0.0000000000000000 GeV^ -4
# Matrix element finite = 5.4803176487726684E-015 GeV^ -4
# Matrix element 1eps = 2.6180321292022329E-029 GeV^ -4
# Matrix element 2eps = -3.4906196282189750E-031 GeV^ -4
#
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