Luminosity, Delphes and Cross Section

Asked by Marlon Brade on 2020-07-28

Hello Madgraph Experts.

Good day. I have a question, Suppose i do simulate p p -> z -> e+ e- and get a cross section. Then what i do next is to fixed the number of events so that i get the luminosity that i want, L = n/cross section . Now, what i do is i will used a Delphes card , say FCC and then run the simulation. Is the number of events now that i fixed will be less than after the Delphes run (Because of the resolution and calorineter efficiencies). Or is it just make a configuration where at the end of Delphes run, i would get the number of events that i wanted which is embedded with my luminosity?

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
2020-07-28
Last query:
2020-07-28
Last reply:
2020-07-28

The number of events in the run_card is the number of events in the lhef file.
(before parton-shower and detector simultation)
If any of those steps drop events -- for wathever reason-- then you will get a smaller amount of events in your final output file.

Cheers,

Olivier

> On 28 Jul 2020, at 15:50, Marlon Brade <email address hidden> wrote:
>
> New question #692114 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/692114
>
> Hello Madgraph Experts.
>
> Good day. I have a question, Suppose i do simulate p p -> z -> e+ e- and get a cross section. Then what i do next is to fixed the number of events so that i get the luminosity that i want, L = n/cross section . Now, what i do is i will used a Delphes card , say FCC and then run the simulation. Is the number of events now that i fixed will be less than after the Delphes run (Because of the resolution and calorineter efficiencies). Or is it just make a configuration where at the end of Delphes run, i would get the number of events that i wanted which is embedded with my luminosity?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Marlon Brade (marlon1994) said : #2

Hello Olivier.

Correct me if i am wrong, so it is just the same if i off the detector card and get the hepfiles then go to a standalone Delphes. Because in my case, i got a hard time when i use the FCC card in Delphes, i always get error. But when i import the hep files in the standalone delhes and run FCC there, its just doing well.

CHeers.

Marlon

correct

> On 28 Jul 2020, at 16:15, Marlon Brade <email address hidden> wrote:
>
> Question #692114 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/692114
>
> Status: Answered => Open
>
> Marlon Brade is still having a problem:
> Hello Olivier.
>
> Correct me if i am wrong, so it is just the same if i off the detector
> card and get the hepfiles then go to a standalone Delphes. Because in my
> case, i got a hard time when i use the FCC card in Delphes, i always get
> error. But when i import the hep files in the standalone delhes and run
> FCC there, its just doing well.
>
> CHeers.
>
> Marlon
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Marlon Brade (marlon1994) said : #4

Hello Olivier.

Thanks sir.

Marlon Brade (marlon1994) said : #5

Thanks Olivier Mattelaer, that solved my question.