Poles do not cancel p p > e+ ve [QCD] in loop_sm-full: charm mass

Asked by Chris Hays on 2020-07-10

Hi,
  I am trying to generate ppbar->e+ ve at NLO including the CKM matrix. I generate p p > e+ ve [QCD] after importing loop_sm-full. I edit the run card to use 1 and -1 for lpp1 and lpp2 and launch and I get the following:

INFO: P0_dxc_epve
INFO: Result for test_ME:
INFO: Passed.
INFO: Result for test_MC:
INFO: Passed.
INFO: Result for check_poles:
Error detected in "launch auto "
write debug file /data/atlas/atlasdata2/hays/madgraph/MG5_aMC_v2_7_3/WplusCKMNLO/run_02_tag_1_debug.log
If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
aMCatNLOError : Poles do not cancel, run cannot continue

  The poles successfully cancel for anything with a u. For cdx and csx I get a warning that 0 points have been tried. I suspected it was due to the non-zero charm mass, so I set it to zero -- this allows it to run further but eventually I get errors in the calculations with charm:

 Error #6 in fks_Sij Infinity

Do you have any suggestions? I am using MG 2.7.3 and pdf set 10550 (cteq66).

Thanks,
Chris

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
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Last query:
2020-07-10
Last reply:
2020-07-10

Hi,

It is important that your definition of the proton content (and jet definition)
matches the number of massless QCD particles of your model.

so for a 4 flavor computation you should have
define p = g u u~ d d~ s s~ c c~
define j = p
for 3 flavor computation you should have
define p = g u u~ d d~ s s~
define j = p

It is important that massless particles are set to ZERO at the model level (so changing the value of the mass to zero within the param_card is too late).

In order to set the mass to zero without having the regenerate the UFO model, you can follow this FAQ:
https://answers.launchpad.net/mg5amcnlo/+faq/2312 <https://answers.launchpad.net/mg5amcnlo/+faq/2312>

Cheers,

Olivier

> On 10 Jul 2020, at 13:31, Chris Hays <email address hidden> wrote:
>
> New question #691795 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/691795
>
> Hi,
> I am trying to generate ppbar->e+ ve at NLO including the CKM matrix. I generate p p > e+ ve [QCD] after importing loop_sm-full. I edit the run card to use 1 and -1 for lpp1 and lpp2 and launch and I get the following:
>
> INFO: P0_dxc_epve
> INFO: Result for test_ME:
> INFO: Passed.
> INFO: Result for test_MC:
> INFO: Passed.
> INFO: Result for check_poles:
> Error detected in "launch auto "
> write debug file /data/atlas/atlasdata2/hays/madgraph/MG5_aMC_v2_7_3/WplusCKMNLO/run_02_tag_1_debug.log
> If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
> aMCatNLOError : Poles do not cancel, run cannot continue
>
> The poles successfully cancel for anything with a u. For cdx and csx I get a warning that 0 points have been tried. I suspected it was due to the non-zero charm mass, so I set it to zero -- this allows it to run further but eventually I get errors in the calculations with charm:
>
> Error #6 in fks_Sij Infinity
>
> Do you have any suggestions? I am using MG 2.7.3 and pdf set 10550 (cteq66).
>
>
> Thanks,
> Chris
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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