MadAnalysis 5

Plotting normalized cross-sections

Asked by prashant sundaram

Hi,

I have generated events for a BSM model from madgraph (10000 events)and i have the output in .lhe format.I want to plot the PT of the leading jet , such that i want normalized distributions i.e((1/sigma)*d(sigma)/dpT). I tried to calculate luminosity from the cross-section that i got from madgraph.I did the following in madanalysis5

set defaultset.xsection = 7.83
set main.normalize = lumi
set main.lumi = 1280
select (j) PT > 0
plot PT (j[1]) 50 0 500 [logY]
submit

and in the output folder i see i don't get normalized cross-sections, probably i am doing something wrong which i am not able to figure out, so please help me out with this.

Regards,
Prashant Sundaram

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Benjamin Fuks (fuks) said : 		#1

Hi Prashant,

Which files are you looking at exactly? The histograms present in the Output/Histos sub-folder should be correctly normalised.

Cheers,

Benjamin

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prashant sundaram (psundaram) said : 		#2

Hi Benjamin,

I am looking at the Output/PDF subfolder and the Output/Histos folder does'nt have any plots, i can see there is only a .py file which is the file that plots the histograms and a few root files in that subfolder.

Regards,
Prashant

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Jack Y. Araz (jackaraz) said : 		#3

Hi Prashant

First of all, please see this question <https://answers.launchpad.net/madanalysis5/+question/693494>, its kind of similar to what you are trying to do. If you want to get the normalized histograms in the normal mode I would suggest setting lumi = (1/1000) * (1/xsec) so that when Ma5 normalizes your results it will give you what you need. Note that it will still say events in the y-axis but you can change it from the python codes that you found already.

PS: 1/1000 because ma5 assumes that you are giving the lumi in fb-1. 1/xsec because your histogram bins will be bin efficiency per dpt where dpt = 10 GeV in your case. Ma5 will take this bin value and multiply via xsec so you will get dsig/dpt then it will multiply it with 1000*lumi and since you modified the lumi as (1/1000) * (1/xsec) you will get 1/sig dsig/dpt.

Cheers

—
Jack Y. Araz

> On Oct 19, 2020, at 12:20 PM, prashant sundaram <email address hidden> wrote:
>
> Question #693523 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/693523
>
> prashant sundaram posted a new comment:
> Hi Benjamin,
>
> I am looking at the Output/PDF subfolder and the Output/Histos folder
> does'nt have any plots, i can see there is only a .py file which is the
> file that plots the histograms and a few root files in that subfolder.
>
> Regards,
> Prashant
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

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