Error Generate Event needed

This means that you have a singularity in your matrix-element which is not removed by cut.
This is why your cross-section is so-large and why the error associated to the such cross-section is so large as well.

For obvious reason if you have divergent matrix-element, the code will never converge (so it will try for a very long time) and you will observe exactly this behavior (large cross-section, large error and few events).
So I do not think that this is a bug on our side but rather a bug in your model/cuts.

Cheers,

Olivier

Hello Olivier,

Many thanks for your replay,

I am not using any special cut, actually, I am keeping the default cut.

I am interested to generate top-quark pair production at NLO QCD with SMEFT contributions with spincorrelation between the decay product, after that, I would like to play with Wilson coefficient using run Card.

I have changed my process to

//////////////// My script ////////////////////////////////

define p = g u c d s u~ c~ d~ s~
define j = g u c d s u~ c~ d~ s~
define l+ = e+ mu+
define l- = e- mu-
define vl = ve vm vt
define vl~ = ve~ vm~ vt~

import model SMEFTatNLO-NLO
generate p p > t t~ QCD=2 QED=0 NP=2 [QCD] (t > b W+, W+ > l+ vl), (t~ > b~ W-, W- > l- vl~ )

output my_EFT_data
launch
analysis = ExRoot

set nevent = 100
set ebeam1 6500
set ebeam2 6500

set MT 172.5

launch -n top_172_5

//////////////// My script ////////////////////////////////

I hope I got it right ? I appreciate any kind of suggestions and helps.

Cheers,
A.Tnourji

Hi,

The syntax:
 generate p p > t t~ QCD=2 QED=0 NP=2 [QCD] (t > b W+, W+ > l+ vl), (t~ > b~ W-, W- > l- vl~ )
is not supported (and indeed crash on the last version of the code).
You can not specify decay for NLO processes (for this you have to use the MadSpin package --the package has spin-correlation--).

If you do not understand why your matrix-element is singular, I would suggest to contact the author of the model (if not you) to understand why this is singular.

Cheers,

Olivier

Hi Olivier,

Thank you for your time and reply :).

1. You can not specify decay for NLO processes (for this you have to use the MadSpin package --the package has spin-correlation--) :

Thank you, I did know about this. I will try to understand how to use MadSpin. ( in case there is a quick tutorial, I will be very grateful )

2. I tried a very simple model which I suppose to work without errorr ( following this website http://feynrules.irmp.ucl.ac.be/wiki/SMEFTatNLO ) :

////////////////// code //////////////

import model SMEFTatNLO-NLO

generate p p > t t~ QCD=2 QED=0 NP=2 [QCD]

output test_dir

launch

shower=pythia8

set nevents 100

////////////////// End code //////////////

But I got this error :

//////// Error ///////////

Error detected in "launch auto "
write debug file /home/delphes/Working_Dir/EFT_Dir/run_01_tag_1_debug.log
If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
aMCatNLOError : An error occurred during the collection of results.
 Please check the .log files inside the directories which failed:
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uux_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uux_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ccx_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ccx_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ddx_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ddx_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uxu_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uxu_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_cxc_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_cxc_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_dxd_ttx/GF3/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_dxd_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bbx_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bbx_ttx/GF5/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bxb_ttx/GF4/log.txt
 /home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bxb_ttx/GF5/log.txt

//////////////// End Error //////////////////////////////

Let me know what I can do to fix this.

Thanks a lot for your insights and advice.

A.Tnourji

Hi,

For completeness, you below the run_01_tag_1_debug.log :

vim /home/delphes/Working_Dir/EFT_Dir/run_01_tag_1_debug.log

////////////// File ///////////////////

launch auto
Traceback (most recent call last):
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/extended_cmd.py", line 1515, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/extended_cmd.py", line 1464, in onecmd_orig
    return func(arg, **opt)
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/amcatnlo_run_interface.py", line 1687, in do_launch
    evt_file = self.run(mode, options)
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/amcatnlo_run_interface.py", line 1921, in run
    jobs_to_collect,mint_step,mode,mode_dict[mode],fixed_order=False)
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/amcatnlo_run_interface.py", line 2136, in collect_the_results
    self.append_the_results(jobs_to_run,integration_step)
  File "/home/delphes/MG5_aMC_v2_7_0/madgraph/interface/amcatnlo_run_interface.py", line 2576, in append_the_results
    '\n'.join(error_log)+'\n')
aMCatNLOError: An error occurred during the collection of results.
Please check the .log files inside the directories which failed:
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uux_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uux_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ccx_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ccx_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ddx_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_ddx_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uxu_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_uxu_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_cxc_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_cxc_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_dxd_ttx/GF3/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_dxd_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bbx_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bbx_ttx/GF5/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bxb_ttx/GF4/log.txt
/home/delphes/Working_Dir/EFT_Dir/SubProcesses/P0_bxb_ttx/GF5/log.txt

Value of current Options:
              text_editor : None
      notification_center : True
                    pjfry : None
"~/Working_Dir/EFT_Dir/run_01_tag_1_debug.log" 113L, 6006C 1,1 Top

////////////// File ///////////////////

Cheers

This model is everything but a simple model. As stated in their manual (the link that you quote):

"The 3.0.3-neworders development branch (​tarball) of MG is required for NLO predictions involving four-fermion operators and (in general) H2G2 with coefficient cpG not normalized with any power of gS."

Note that such version is an alpha version out of a beta version (version 3 is still in beta). So I can not recommend anyone (but developers or very advanced used) to use that version for the moment.

So if you want to learn how the code works please use a much simpler model like "loop_sm"

Cheers,

Olivier

Hello Olivier,

Sorry for my late reply, I get in touch with SMEFT@NLO and the error is solved by sitting all 4f operators to 0 when using MadGraph2.XX.

Cheers,
A.Tnourji.