1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
#
# 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 PLUGIN/GGVV/CrossCheck_ML_epemepem.mg5
#
# And it will generate the output for this process using MadLoop only (standalone)
#
# Make sure to remove any existing old output
!rm -rf CrossCheck_ML_gg_epemepem
#
# We start from the same model as for the GGVV counterpart so as to insure consistency
import model PLUGIN/GGVV/GGVV_UFO_model-crosscheck
#
# The order specification is make sure none of the Form Factors contributions are considered
# The option --loop_filter=n>3 is necessary to insure that none of the triangle topology
# is taken into account by MadGraph
# Notice that here we use 'sqrvirt=QCD' to indicate that we are interested in the squared
# one-loop matrix element.
generate g g > e+ e- e+ e- GGWW<=0 GGZA<=0 GGZZ<=0 GGAA<=0 [sqrvirt=QCD] --loop_filter=n>3 @1001
output CrossCheck_ML_gg_epemepem
#
# The launch below will initialize the loop ME and display the resulting squared one-loop
# ME for the first point
launch -f
#
# But we can also run it by hand
!cd CrossCheck_ML_gg_epemepem/SubProcesses/P1001_gg_epemepem && ./check
#
# The result should be:
#
# 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 finite = 5.4803176487725517E-015 GeV^ -4
# ---------------------------------
#
|