MadAnalysis 5

THT different between ma5 v1.3 and v1.4

Asked by Bibhushan Shakya

When I look at the distribution of H_T for the same dataset , v1.3 and v1.4 (looking at the .lhco and .root files respectively, generated with madgraph5) give very different results. what is the source of this discrepancy?

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Benjamin Fuks
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Benjamin Fuks (fuks) said : 		#1

There was no change on the HT definition. How were the event files generated?

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Bibhushan Shakya (bibhushan) said : 		#2

The event files were generated with the MadGraph5_aMC@NLO package, v2.2.3 (with Delphes 3.2.0). When I look at the tag_1_delphes_events.lhco file with madanalysis v1.4 versus when I look at the tag_1_delphes_events.root file with madanalysis v1.3, looking at the MET distribution, cutting on number of leptons, jets etc gives identical results, but the HT distribution is very different.

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Benjamin Fuks (fuks) said : 		#3

Hi,

The information in the LHCO file is not the same as the one embedded in the delphes file. That could imply differences for some observables, and I am not surprized by your findings.

Cheers,

Benjamin

On 27 Sep 2016, at 11:47 , Bibhushan Shakya <email address hidden> wrote:

> Question #402326 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/402326
>
> Status: Answered => Open
>
> Bibhushan Shakya is still having a problem:
> The event files were generated with the MadGraph5_aMC@NLO package,
> v2.2.3 (with Delphes 3.2.0). When I look at the
> tag_1_delphes_events.lhco file with madanalysis v1.4 versus when I look
> at the tag_1_delphes_events.root file with madanalysis v1.3, looking at
> the MET distribution, cutting on number of leptons, jets etc gives
> identical results, but the HT distribution is very different.
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

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Bibhushan Shakya (bibhushan) said : 		#4

My impression was that both the lhco and root files are generated by Delphes, and the information in the lhco file is just a subset of the information of the root file, and that the lhco file is what comes out of the lhco2root conversion by Delphes?

As a side note, while exploring this issue further, I found that similar problems might have been encountered before (e.g. https://answers.launchpad.net/madanalysis5/+question/271900).

So my take-away message from all this is that there might be issues with the root->lhco conversion, and I should trust the results from the root file over the lhco file. Would you say this is reasonable?

Thanks!

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Best Benjamin Fuks (fuks) said : 		#5

Hi,

>
> So my take-away message from all this is that there might be issues with
> the root->lhco conversion, and I should trust the results from the root
> file over the lhco file. Would you say this is reasonable?
Yes it is reasonnable.

Cheers,

Benjamin

Revision history for this message
Bibhushan Shakya (bibhushan) said : 		#6

Thanks Benjamin Fuks, that solved my question.