Fails to reach target (v2.7.0)

Asked by Shubham Gantayet on 2020-03-10

Hi,

Generating events for the process p p > Z{0} Z{0} j j QCD=0, with ebeam1 and ebeam2 = 13500.0, gives the 'INFO: fail to reach target 10000' (roughly 3500 events are produced instead). This is using v2.7.0, with no other run parameters changed.

Would I need to introduce any additional cuts for this to run? If so, how would I find where the error is occurring? This same process runs fine at the default ebeam = 6500.0.

Thanks.

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Shubham Gantayet
Solved:
2020-03-11
Last query:
2020-03-11
Last reply:
2020-03-10

Hi,

VBF type of process are now to be quite unefficient for event generation.
This is not something new ( I face that issue more than 6 years ago...)
At the same time, some work of one of my colleague might fix this issue in a future version.

The only advise, I can do for the moment is to use 2.7.1 and set in the run_card the
line
True = hard_process

This might help a bit.

Cheers,

Olivier

> On 10 Mar 2020, at 13:13, Shubham Gantayet <email address hidden> wrote:
>
> New question #689238 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/689238
>
> Hi,
>
> Generating events for the process p p > Z{0} Z{0} j j QCD=0, with ebeam1 and ebeam2 = 13500.0, gives the 'INFO: fail to reach target 10000' (roughly 3500 events are produced instead). This is using v2.7.0, with no other run parameters changed.
>
> Would I need to introduce any additional cuts for this to run? If so, how would I find where the error is occurring? This same process runs fine at the default ebeam = 6500.0.
>
> Thanks.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Shubham Gantayet (sgantayet) said : #2

Hi,

I am trying to use v2.7.1, but setting True = hard_process in the run_card gives the following error:

Error: Symbol 'hard_process' at (1) has no IMPLICIT type

Any ideas why? It seems to be a compilation error, could the gfortran version be an issue?

Thanks.

Sorry my mistake, I miss remember the name of the parameter.
This is hard_survey and not hard_process

Sorry,

Olivier

> On 10 Mar 2020, at 19:47, Shubham Gantayet <email address hidden> wrote:
>
> Question #689238 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/689238
>
> Shubham Gantayet posted a new comment:
> Hi,
>
> I am trying to use v2.7.1, but setting True = hard_process in the
> run_card gives the following error:
>
> Error: Symbol 'hard_process' at (1) has no IMPLICIT type
>
> Any ideas why? It seems to be a compilation error, could the gfortran
> version be an issue?
>
> Thanks.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Shubham Gantayet (sgantayet) said : #4

Thanks Olivier, that takes a bit longer to run but now produces around 8000 events which is very helpful!