How to change the normalization of a histogram such that its area is equal to the total cross section?

Asked by oleh on 2018-01-30

Dear MadAnalysis experts,

I would like to know is it possible to rescale a histogram in MadAnalysis (in the user-friendly mode)
in such a way that the area of the histogram becomes equal to the total cross section.

For example I create a pT histogram (using MadGraph events),
so I type plot PT(jet) 100 10 100 and I then I would like to get the total cross section in the cell called Integral in my PDF report, or in other words I want to rescale the histogram in such a way that a sum bin width times bin height over the histogram gives me a total cross section.

I tried to change normalization using main set.lumi and <set>.xsection = <value> but it doesn't do exactly what I want.

I also written a simple python script which runs through a histogram data produced by MadAnalysis and rescales everything the way I need, but I wonder is there a possibility to do it from the MadAnalysis command line?

Thank you!

With best regards,
Oleh

Question information

Language:
English Edit question
Status:
Solved
For:
MadAnalysis 5 Edit question
Assignee:
No assignee Edit question
Solved by:
oleh
Solved:
2018-02-01
Last query:
2018-02-01
Last reply:
2018-01-31
Benjamin Fuks (fuks) said : #1

Dear Oleh,

You can change the total rate of the sample (set datasetname.xsection = …) and chabnge the lumi accordingly. This should do the job. I don't understand why it does not work in your case.

Cheers,

Benjamin

> On 30 Jan 2018, at 13:42 , oleh <email address hidden> wrote:
>
> New question #663842 on MadAnalysis 5:
> https://answers.launchpad.net/madanalysis5/+question/663842
>
> Dear MadAnalysis experts,
>
> I would like to know is it possible to rescale a histogram in MadAnalysis (in the user-friendly mode)
> in such a way that the area of the histogram becomes equal to the total cross section.
>
> For example I create a pT histogram (using MadGraph events),
> so I type plot PT(jet) 100 10 100 and I then I would like to get the total cross section in the cell called Integral in my PDF report, or in other words I want to rescale the histogram in such a way that a sum bin width times bin height over the histogram gives me a total cross section.
>
> I tried to change normalization using main set.lumi and <set>.xsection = <value> but it doesn't do exactly what I want.
>
> I also written a simple python script which runs through a histogram data produced by MadAnalysis and rescales everything the way I need, but I wonder is there a possibility to do it from the MadAnalysis command line?
>
> Thank you!
>
> With best regards,
> Oleh
>
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

oleh (fedkevych) said : #2

Dear Benjamin,

many thanks for finding time to answer my question.

Indeed I had to play around more and change both parameters properly.

Sorry for bothering.

With best regards,
Oleh