Having trouble extracting result with only EFT vertices.

Asked by Ji-Chong Yang

Hello!

We need some help!
We are using MadGraph 2.7.2 with a UFO file containing some anormalus AAAZ, AAZZ, AZZZ, WWZZ vertices.

With FM2=8.0e-12, and all other EFT coefficients set to be 0
When we use p p > j j a z NP=1 QED=3 QCD=0 $$a z w+ w- to extract the VBS contribution induced by those anormaluse vertices, and followed by a madspin z > l+ l-, we find at 14TeV it was about 2.8fb(before madspin is about 40.7 fb)
Then we use p p > j j a l+ l- NP=1 QED=4 QCD=0 to include also tri-boson channels, we find the result is about 0.49fb, which is much smaller.
We think that it is not possible for the intereference to reduce the cross-section so much, so we run
generate p p > a > a z z
add process p p > a > a a z
add process p p > z > a z z
add process p p > z > a a z
add process p p > w+ > w+ a z
add process p p > w- > w- a z
Without madspin, the result is about 8fb so the tri-boson contribution to p p > j j l+ l- a should be smaller than 1fb, couldn't suppress the VBS so much (from 2.8fb to 0.49fb).

I think we must have made some mistakes, we need your help!

I have preserved all files to reproduce the problem if you need (I don't know how to attach them)

Thanks in advance!
Best regards!

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
Last query:
Last reply:
Revision history for this message
Olivier Mattelaer (olivier-mattelaer) said :
#1

What is your lepton cut?

Cheers,

Olivier

Revision history for this message
Ji-Chong Yang (nbalexis) said :
#2

Dear Olivier!

We use the Standard Cuts as default settings (we only change the energy of beams in run_card and coefficients in param_card)
It is:

 10.0 = ptl ! minimum pt for the charged leptons
 -1.0 = ptlmax ! maximum pt for the charged leptons

 2.5 = etal ! max rap for the charged leptons
 0.0 = etalmin ! main rap for the charged leptons

 0.4 = drll ! min distance between leptons
 0.4 = drjl ! min distance between jet and lepton
 0.4 = dral ! min distance between gamma and lepton
 -1.0 = drllmax ! max distance between leptons
 -1.0 = drjlmax ! max distance between jet and lepton
 -1.0 = dralmax ! maxdistance between gamma and lepton

 0.0 = mmll ! min invariant mass of l+l- (same flavour) lepton pair
 -1.0 = mmllmax ! max invariant mass of l+l- (same flavour) lepton pair

 0.0 = mmnl ! min invariant mass for all letpons (l+- and vl)
 -1.0 = mmnlmax ! max invariant mass for all letpons (l+- and vl)

 0.0 = ptllmin ! Minimum pt for 4-momenta sum of leptons(l and vl)
 -1.0 = ptllmax ! Maximum pt for 4-momenta sum of leptons(l and vl)

 0.0 = xptl ! minimum pt for at least one charged lepton

 0.0 = ptl1min ! minimum pt for the leading lepton in pt
 0.0 = ptl2min ! minimum pt for the second lepton in pt
 -1.0 = ptl1max ! maximum pt for the leading lepton in pt
 -1.0 = ptl2max ! maximum pt for the second lepton in pt

Thank you for reply, we need your help!

Best Regards!

Revision history for this message
Best Olivier Mattelaer (olivier-mattelaer) said :
#3

So this is your issue.
MadSpin does not apply any cut on the decaying particles.

Cheers,

Olivier

Revision history for this message
Ji-Chong Yang (nbalexis) said :
#4

Dear Olivier!

We try to change drll from 0.4 to 0.001, and the cross-section increase to 2.6fb
That solved my problem!

Thank you very much!

Revision history for this message
Ji-Chong Yang (nbalexis) said :
#5

Thanks Olivier Mattelaer, that solved my question.