Unknown particle by Delphes in the final state

Asked by Özer Özdal on 2019-08-07

Hi,

I am working on a model which offers a new stable, invisible particle with the PDGID=6000012. I recast the hepmc file in MadAnalysis after it has been processed in the MG/Pythia chain. Unless I change the PDGID of that particle to 18 and redo the same modifications, I always get the following warning messages in MadAnalysis.

WARNING: --------------------------------------------------------------------------------
WARNING: Msg | Unknown particle by Delphes in the final state
WARNING: Details | particle with PDGID=6000012
WARNING: Where | Function = TranslateMA5toDELPHES ; File=delphes/DetectorDelphes.cpp ; Line=295
WARNING: --------------------------------------------------------------------------------
WARNING: --------------------------------------------------------------------------------
WARNING: Msg | Unknown particle by Delphes in the final state
WARNING: Details | particle with PDGID=-6000012
WARNING: Where | Function = TranslateMA5toDELPHES ; File=delphes/DetectorDelphes.cpp ; Line=295
WARNING: --------------------------------------------------------------------------------

The warning message still remains after I made the following modifications.

1) I defined invisible = invisible +6000012 -6000012

2) I added the following line both int the hcal and ecal:

   add EnergyFraction {6000012} {0.0 0.0}

3) I added the following lines under Neutrino Filter.

 add PdgCode {6000012}
 add PdgCode {-6000012}

4) I added the following lines in particle.tbl file under madanalysis5/tools/SampleAnalyzer.

     6000012 scotino_1 0 500.00000 1.00000 0.00000E+00
    -6000012 scotino_1~ 0 500.00000 1.00000 0.00000E+00

Is there anything else that I should modify ? Why do I have to choose the PDG id = 18 to get rid of that warning ?

Thanks in advance,
Ozer

Question information

Language:
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Status:
Answered
For:
MadAnalysis 5 Edit question
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Last query:
2019-08-08
Last reply:
2019-08-20
Özer Özdal (oozdal) said : #1

Hi,

[Update] If PID is not included in the ROOT’s PDG table, then the particle is rejected. Thus, I change the line 291 of DetectorDelphes.cpp under tools/SampleAnalyzer/Interfaces/delphes as in the following in order to avoid the particle being rejected by MadAnalysis.

    if (pdgParticle==0 and pdgCode!=6000012) // Unknown particle?
(Here 6000012 is the pid of the new stable particle I am using.)

It solved my problem but is it safe enough to do this ? Would it be better if I made the similar modification in the line 418 of DelphesHepMCReader.cc file under tools/delphes/classes instead of changing DetectorDelphes.cpp ?

https://cp3.irmp.ucl.ac.be/projects/delphes/browser/git/classes/DelphesHepMCReader.cc#L388

Cheers,

Özer

Benjamin Fuks (fuks) said : #2

Hi Ozer,

It is very dangerous to modify the files and I don't recommend it. In this case, the warning is appropriate: there is a new (generator-level) particle that is unknown to delphes. Nothinfg less, nothing more. As the delphes card has been correctly modified, there is nothing to worry about it.

Cheers,

Benjamin

> On 8 Aug 2019, at 20:08 , Özer Özdal <email address hidden> wrote:
>
> Question #682689 on MadAnalysis 5 changed:
> https://answers.launchpad.net/madanalysis5/+question/682689
>
> Özer Özdal gave more information on the question:
> Hi,
>
> [Update] If PID is not included in the ROOT’s PDG table, then the
> particle is rejected. Thus, I change the line 291 of DetectorDelphes.cpp
> under tools/SampleAnalyzer/Interfaces/delphes as in the following in
> order to avoid the particle being rejected by MadAnalysis.
>
> if (pdgParticle==0 and pdgCode!=6000012) // Unknown particle?
> (Here 6000012 is the pid of the new stable particle I am using.)
>
> It solved my problem but is it safe enough to do this ? Would it be
> better if I made the similar modification in the line 418 of
> DelphesHepMCReader.cc file under tools/delphes/classes instead of
> changing DetectorDelphes.cpp ?
>
> https://cp3.irmp.ucl.ac.be/projects/delphes/browser/git/classes/DelphesHepMCReader.cc#L388
>
> Cheers,
>
> Özer
>
> --
> You received this question notification because you are an answer
> contact for MadAnalysis 5.

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