MadGraph v2.7.0 fails to reach target number of events

Hi,

>generate p p > mu+ mu+ j j BSMHIGGS^2>1 N^2>1 @1
>add process p p > mu+ mu+ j j BSMHIGGS^2>1 N^2>1 @2

I guess you made a typo above since those are twice the same line (or I miss the difference at least)

>I have not applied any cuts at all.

Are you sure that you do not have singularity (even integrable singularity)?

>My problem comes in when, for some combinations of theory model parameters, MadGraph fails to reach the required number of events (10000). The info message appears as shown below:

This is actually not surprising... The phase-space integration for interference is something that we do not know how to do in an efficient way. We are using the standard madevent technique to do such phase-space integration/event generation and as expected the machine learning layer (VEGAS) can compensate for some cases but not always (as usual machine learning is great to refine but if you are too bad to start with...)

In 2.7.1 [going to be release this week], we have a new (hidden) option of the run_card
hard_process if you set it on True, it will perform the computation with more event per iteration. This might allow VEGAS to better compensate in those cases.

Cheers,

Olivier

Hi Olivier,

Thank you for your quick reply.

I am not aware of any singularities, but is there a way I can identify singularities from the MadGraph output?

Hopefully with the new realese the hard_process feature helps. Until then, am I right to assume the cross-section produced is not trustworthy?

Cheers,
Mohamed

> , am I right to assume the cross-section produced is not
> trustworthy?

It is not necessarily wrong. but indeed not having the correct number of events is a sign of difficulty of the phase-space integrator and this means it is more likely than usual to face bias for the integrator.
Running multiple run with various seed can be a test if this is the result is stable or not.

Cheers,

Olivier

> On 9 Mar 2020, at 21:37, Mohamed Aly <email address hidden> wrote:
>
> Question #689230 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/689230
>
> Mohamed Aly posted a new comment:
> Hi Olivier,
>
> Thank you for your quick reply.
>
> I am not aware of any singularities, but is there a way I can identify
> singularities from the MadGraph output?
>
> Hopefully with the new realese the hard_process feature helps. Until
> then, am I right to assume the cross-section produced is not
> trustworthy?
>
> Cheers,
> Mohamed
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi,

I am revisiting this at the moment and realised I had another separate question: what is the largest BSMHIGGS^2 and N^2 would MadGraph generate and what setting changes that?

Cheers,
Mohamed

Since your model has this:

BSMHIGGS = CouplingOrder(name='BSMHIGGS',
 expansion_order = 99,
 hierarchy = 2 )

the limit should be at 99*2=188

Cheers,

Olivier

> On 13 Apr 2020, at 23:32, Mohamed Aly <email address hidden> wrote:
>
> Question #689230 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/689230
>
> Mohamed Aly posted a new comment:
> Hi,
>
> I am revisiting this at the moment and realised I had another separate
> question: what is the largest BSMHIGGS^2 and N^2 would MadGraph generate
> and what setting changes that?
>
> Cheers,
> Mohamed
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Makes perfect sense, thank you. Seeing that I asked for BSMHIGGS^2>1 and N^2>1 would MadGraph generate all possible combinations, or would it automatically only generate the combination of smallest or second to smallest BSMHIGGS^2 and N^2? I thought MadGraph minimses the coupling orders in the process generation if one does not specify any condition, and I thought this may be the case here as well?

The reason why I am asking is because, if I generate my process with BSMHIGGS^2>1 and N^2>1 I get 34 processes with 2856 diagrams. I get the same number of diagrams and processes by asking BSMHIGGS^2<=7(or 5 or 4) and N^2>1 but i get less diragrams when asking BSMHIGGS^2<=3. This made me think that MadGraph is generating only up to 4 of BSMHIGGS^2 because I know that there are non-zero number of diagrams with BSMHIGGS^2 > 4.

Cheers,
Mohamed

> I thought MadGraph minimses the coupling
> orders in the process generation if one does not specify any condition,
> and I thought this may be the case here as well?

No this is only the case (minimization) when NO coupling order are specified.
In any other case the only limit is the one related to the model.

> The reason why I am asking is because, if I generate my process with
> BSMHIGGS^2>1 and N^2>1 I get 34 processes with 2856 diagrams. I get the
> same number of diagrams and processes by asking BSMHIGGS^2<=7(or 5 or
> 4) and N^2>1 but i get less diragrams when asking BSMHIGGS^2<=3. This
> made me think that MadGraph is generating only up to 4 of BSMHIGGS^2
> because I know that there are non-zero number of diagrams with
> BSMHIGGS^2 > 4.

Without the model I cannot comment. They are certainly a reason for that.
just ask with BSMHIGGS^2 > 4 and will likely see that all those diagram have N=0 or something like that.

Cheers,

Olivier

> On 13 Apr 2020, at 23:52, Mohamed Aly <email address hidden> wrote:
>
> Question #689230 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/689230
>
> Mohamed Aly posted a new comment:
> Makes perfect sense, thank you. Seeing that I asked for BSMHIGGS^2>1 and
> N^2>1 would MadGraph generate all possible combinations, or would it
> automatically only generate the combination of smallest or second to
> smallest BSMHIGGS^2 and N^2? I thought MadGraph minimses the coupling
> orders in the process generation if one does not specify any condition,
> and I thought this may be the case here as well?
>
> The reason why I am asking is because, if I generate my process with
> BSMHIGGS^2>1 and N^2>1 I get 34 processes with 2856 diagrams. I get the
> same number of diagrams and processes by asking BSMHIGGS^2<=7(or 5 or
> 4) and N^2>1 but i get less diragrams when asking BSMHIGGS^2<=3. This
> made me think that MadGraph is generating only up to 4 of BSMHIGGS^2
> because I know that there are non-zero number of diagrams with
> BSMHIGGS^2 > 4.
>
> Cheers,
> Mohamed
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.