WARNING: MadAnalysis5 failed to write a parton-level default analysis card for this process.

Hi,

> WARNING: Failed to update dependent parameter. This might create trouble for external program (like MadSpin/shower/...)

This warning means that we were not able to check/update the value of the dependent parameter of your param_card. This means that the W mass will not be changed if you set it to an inconsistent value (same for other dependent parameter).

This will NOT impact MG5aMC, since we never read the value of those parameter in the param_card. But some other code might read those and if set to an inconsistent value with the other input of the card might lead to inconsistencies.

So this not related at all to your process returning zero cross-section.

> When I launch the same process but with Z instead of Zp, it gives the same results. When I use, say, e ebar instead of neutrinos, either with z or zp and with or without showering and detector simulations, it works fine. Also, it works fine when I use some other model. So, I think the problem is with neutrinos, how I can I proceed avoiding this problem?

What I would suggest to test is that
1) what is the cross-section for
p p > z
and
p p > zp
2) what is the width for
z > nu nu
and
zp > nu nu

If those widths are zero (for whatever reason) then this would explain your issue.
In that case, please check your model/param_card to understand why those widths are zero.

2) Check your cut, in principle here, you do not need any cuts.
so to be sure to not have any cut, you can do the following:
when you have the following question:

> Do you want to edit a card (press enter to bypass editing)?
> /------------------------------------------------------------\
> | 1. param : param_card.dat |
> | 2. run : run_card.dat |
> | 3. madanalysis5_parton : madanalysis5_parton_card.dat |
> \------------------------------------------------------------/
> you can also
> - enter the path to a valid card or banner.
> - use the 'set' command to modify a parameter directly.
> The set option works only for param_card and run_card.
> Type 'help set' for more information on this command.
> - call an external program (ASperGE/MadWidth/...).
> Type 'help' for the list of available command
> [0, done, 1, param, 2, run, 3, madanalysis5_parton, enter path][90s to answer]

reply by
set no_parton_cut

Since you do not have issue with other problems, this might not be the issue actually

Cheers,

Olivier

> On 20 Feb 2019, at 09:52, Mustafa Ashry <email address hidden> wrote:
>
> New question #678670 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/678670
>
> Dear Olivier,
>
> Whenever I launch the process to MG p p > zp, zp > nu nu , and I edited the parameter card for the MZp and WZp in the BLSM model, and with and without pythia and delphes and I got I obtain the following warnings
>
> WARNING: Failed to update dependent parameter. This might create trouble for external program (like MadSpin/shower/...)
>
> and thus at the end I get the usual results:
>
> Survey return zero cross section.
> Typical reasons are the following:
> 1) A massive s-channel particle has a width set to zero.
> 2) The pdf are zero for at least one of the initial state particles
> or you are using maxjetflavor=4 for initial state b:s.
> 3) The cuts are too strong.
> Please check/correct your param_card and/or your run_card.
>
> I wonder if there is even a relation between the above warning and the zero results.
>
> When I launch the same process but with Z instead of Zp, it gives the same results. When I use, say, e ebar instead of neutrinos, either with z or zp and with or without showering and detector simulations, it works fine. Also, it works fine when I use some other model. So, I think the problem is with neutrinos, how I can I proceed avoiding this problem?
>
> Would you help please.
>
> Thank you in advance
>
> Mustafa
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

It seems that the BLSM model produced by SARAH has a problem itself in the neutrino sector because for the z/zp > nu nu it gave the following again, even by setting no_parton_cut

  === Results Summary for run: run_01 tag: tag_1 ===

     Width : 0 +- 0 GeV
     Nb of events : 0

INFO: End survey
refine 10000
Creating Jobs
INFO: Refine results to 10000
INFO: Generating 10000.0 unweigthed events.
INFO: Effective Luminosity 1.2e+103 pb^-1
INFO: need to improve 0 channels
Survey return zero cross section.
   Typical reasons are the following:
   1) A massive s-channel particle has a width set to zero.
   2) The pdf are zero for at least one of the initial state particles
      or you are using maxjetflavor=4 for initial state b:s.
   3) The cuts are too strong.
   Please check/correct your param_card and/or your run_card.
Zero result detected: See https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FAQ-General-14

Do you have any idea if this relates to the MG anyway, because I think we should trust SARAH, specially for a well built models like BLSM.

Moreover, I obtain the following warnings and I don't know the reasons for them

WARNING: MadAnalysis5 failed to write a parton-level default analysis card for this process.
WARNING: Therefore, parton-level default analysis with MadAnalysis5 will be empty.
WARNING: MadAnalysis5 failed to write a hadron-level default analysis card for this process.
WARNING: Therefore, hadron-level default analysis with MadAnalysis5 will be empty.

Thank you for your help

Mustafa

Hi,

> Do you have any idea if this relates to the MG anyway, because I think we should trust SARAH, specially for a well built models like BLSM.

I highly doubt that this is related to MG. It should be the model.
Did you check:
- The numerical value of the associated coupling(s)
- That the lorentz structure for such vertex is indeed the SM one.

Now if you really think that this is a problem inside MG5aMC, you can send me the model by email (or put a link where i can download it in this thread) and I will check.

Cheers,

Olivier