Generating MadAnalysis5 default cards freezes and gets killed automatically

Asked by Jakub Salko on 2019-10-30


I am trying to pair-produce a VLQ top partner X_5/3 using the model 4FNS_UFO from website with the subsequent decays. I am using the syntax

import VLQ_v4_4FNS_UFO
define allsm = u c d s u~ c~ d~ s~ ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t b t~ b~ ta- ta+
generate p p > x x~ > t w+ t~ w- , ( t > b w+ , ( w+ > allsm allsm ), w+ > allsm allsm ), ( t~ > b~ w- , ( w- > allsm allsm ), w- > allsm allsm )
output out
 shower = Pythia8
 set ebeam1 6500
 set ebeam2 6500
 set KXL1 0
 set KXL2 0
 set KXL3 0.1
 set KXR1 0
 set KXR2 0
 set KXR3 0
 set MX 1000
 set WX auto

and when I run the script, MadGraph gets stuck at "Generating MadAnalysis5 default cards tailored to this process" , freezing my computer and the whole execution gets killed automatically after about 15-20 minutes.
I tried to pass the decay of top quarks and W bosons to MadSpin which works to the point when MadSpin generates the full matrix element squared at which point the whole process gets stuck (no freezing of the machine) at

INFO: generating the full matrix element squared (with decay)
INFO: generate p p > x x~ > t w+ t~ w-, (t~ > b~ w- , w- > allsm allsm QCD=99), w- > allsm allsm QCD=99, w+ > allsm allsm QCD=99, (t > b w+ , w+ > allsm allsm QCD=99) --no_warning=duplicate;

where it takes about 20 minutes to finish after which the "Compiling Code" takes forever (at this stage I just kill the process).

I am wondering if the problem is just in the computational resources of my computer or rather if I am doing something wrong. I am using MadGraph5_aMC@NLO v2.6.7.

Thanks a lot!

Question information

English Edit question
MadAnalysis 5 Edit question
Benjamin Fuks Edit question
Solved by:
Benjamin Fuks
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I confirm the issue, that process use a LOT of RAM in order to generate the default card of MA5... (I killed it manually in my case before it is automatically due to lack of RAM/SWAP)


This is a MA5 issue, so I changed the project related.



Best Benjamin Fuks (fuks) said : #2

Hi Jakub,

The issue was generated by MadAnalysis 5 asking for the computation of many distributions of systems originating from the combination of the various particles available from the decay processes. In the present case, the multiplicity of the chain that was killing us (as there are numerous long decay chains).

I have modified the interface so that if there are more than 75 of such combinations, nothing is printed to the parton-level card and it is up to the user to decide which plots he/she wants. In addition, the number of allowed combinations in the hadron level card is cut down too.

Please re-install madanalysis5 within mg5 and everything should go back to normal.



Jakub Salko (jasalko) said : #3

Thank you very much for your answer. This solved my problem.

Jakub Salko (jasalko) said : #4

Thanks Benjamin Fuks, that solved my question.