Comment 4 for bug 1807699

Hi Peter,

Your model is not on the database of model:

> MG5_aMC> import model SMEFTsim_A_general_alphaScheme_UFO_v2
> DEBUG: no model with that name found online
> Error detected in "import model SMEFTsim_A_general_alphaScheme_UFO_v2"
> write debug file MG5_debug
> If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
> UFOImportError : Path SMEFTsim_A_general_alphaScheme_UFO_v2 is not a valid pathname

So I'm not able to test.
I have quite similar model in the database:
SMEFTsim_A_MFV_alphaScheme_UFO_v2_1 SMEFTsim_A_U35_alphaScheme_UFO_v2_1 SMEFTsim_A_U35_MwScheme_UFO_v2_1/
SMEFTsim_A_MFV_MwScheme_UFO_v2_1 SMEFTsim_A_U35_MwScheme_UFO_v2_1 SMEFTsim_tb1/

But not that one.

But your problem is typical of any 4 point interaction that has all three point vanishing.
In that case we face a limitation of our PS integrator who crashes that way.
The only solution is to simplify the model to avoid to have ANY three-point Feynman diagram.

Cheers,

Olivier

> On 12 Dec 2018, at 01:18, Peter Galler <email address hidden> wrote:
>
> Hi Olivier,
> thanks for your suggestion.
> I hope I understood your post correctly.
> I generated a restriction module by modifying an existing one (restrict_massless.dat)
> within the SMEFT model.
> There all quark masses except the top quark mass are set to zero (not sure if this
> is relevant). Additionally, I set all Wilson coefficients to zero except for cqq3Abs1133
> which is set to one. Running MadGraph with the SMEFTsim model including the restriction
> indeed produces only the four-fermion diagram but when generating the events I get the
> same error as before. Maybe I configured the restriction file incorrectly. It's attached to this post. Or maybe I didn't get the point of your suggestion to use the restriction module.
> Did you use a restriction file to solve this particular issue? If yes, could you send me that restriction file, please?
> Thanks, Peter
>
> ** Attachment added: "restriction module"
> https://bugs.launchpad.net/mg5amcnlo/+bug/1807699/+attachment/5221507/+files/restrict_massless_cqq3Abs1133.dat
>
> --
> You received this bug notification because you are subscribed to
> MadGraph5_aMC@NLO.
> https://bugs.launchpad.net/bugs/1807699
>
> Title:
> problem with "==" notation for 4-fermion couplings in SMEFT
>
> Status in MadGraph5_aMC@NLO:
> Won't Fix
>
> Bug description:
> Dear MadGraph Team,
>
> I encountered an error that I can't resolve
> while generating s-channel single top
> in the SMEFT using only the dimension-six
> squared term (NP==1). Specifically I ran
> the following:
>
> inside the interactive MG environment:
>
> import model SMEFTsim_A_general_alphaScheme_UFO_v2
> generate u d~ > t b~ / a h z NP==1
> output single_top_schannel
>
> in the command line shell (outside of MG):
>
> I set all Wilson coefficients to zero except for
> cqq3Abs1133 using the following commands:
>
> sed -i 's/1\.000000e+00/0\.000000e+00/' single_top_schannel/Cards/param_card.dat
> sed -i '/cqq3Abs1133/ s/0\.000000e+00/1\.000000e+00/' single_top_schannel/Cards/param_card.dat
>
> Then I ran:
>
> ./single_top_schannel/bin/generate_events -f
>
> The following output appears:
>
>
> Generating 10000 events with run name run_01
> survey run_01
> INFO: compile directory
> compile Source Directory
> Using random number seed offset = 21
> INFO: Running Survey
> Creating Jobs
> Working on SubProcesses
> INFO: P1_udx_tbx
> INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 12h19 ]
> STOP 1
> rm: cannot remove ‘results.dat’: No such file or directory
> ERROR DETECTED
> INFO: Idle: 0, Running: 0, Completed: 1 [ 0.12s ]
> INFO: Idle: 0, Running: 0, Completed: 1 [ 0.12s ]
> INFO: End survey
> refine 10000
> Creating Jobs
> INFO: Refine results to 10000
> INFO: Generating 10000.0 unweigthed events.
> Error when reading single_top_schannel/SubProcesses/P1_udx_tbx/G1.2/results.dat
> Command "generate_events -f" interrupted with error:
> ValueError : need more than 5 values to unpack
> Please report this bug on https://bugs.launchpad.net/mg5amcnlo
> More information is found in single_top_schannel/run_01_tag_1_debug.log'.
> Please attach this file to your report.
> quit
> INFO:
>
>
> I'm attaching the log file "run_01_tag_1_debug.log" as well as the log file
> "single_top_schannel/SubProcesses/P1_udx_tbx/G1.2/log.txt". In the second
> log file you can find the error message:
> "Problem in the multi-channeling. All amp2 are zero but not the total matrix-element"
> It seems as if this message is generated by the "DiscreteSampler module" written
> by "Valentin Hirschi" so he might be the appropriate person to forward this
> bug report to.
>
> I'm using MadGraph5_aMC@NLO version 2.6.4 on Ubuntu 14.04.
>
> I might add that this error seems to occur for 4-fermion operators only.
> The "NP==1" notation also does not work for example for cqq1Abs1331 but it does
> work for example for cuWAbs3x3. Generating the whole matrix element (sm + sm*eft + eft^2)
> works for both 4-fermion and non-4-fermion operators.
>
> Thanks, Peter
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/mg5amcnlo/+bug/1807699/+subscriptions