MadGraph5_aMC@NLO

increasing the precision/ reducing the uncertainty

Asked by Fatemeh Elahi

Hi,

I am trying to find the effect of a certain parameter in the cross section of the process p p > e+ e- mu+ mu-, so I am running this process for different values of that parameter. However, the change in cross section is overwhelmed by the uncertainty that madgraph gives me. Could you please let me know how I can increase the precision and reduce the uncertainty?

Best,

Fatemeh

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Olivier Mattelaer (olivier-mattelaer) said : 		#1

Hi,

The easiest is to increase the number of events requested and if you need too many, then use multi_run mode.
Note that the error quoted are only the statistical error which is typically much lower than the systematical error (pdf and scale)

Cheers,

Olivier

On Sep 15, 2014, at 7:26 PM, Fatemeh Elahi <email address hidden> wrote:

> New question #254553 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/254553
>
> Hi,
>
> I am trying to find the effect of a certain parameter in the cross section of the process p p > e+ e- mu+ mu-, so I am running this process for different values of that parameter. However, the change in cross section is overwhelmed by the uncertainty that madgraph gives me. Could you please let me know how I can increase the precision and reduce the uncertainty?
>
> Best,
>
> Fatemeh
>
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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