 Charged Hits in Neutral List [message #17139] |
Fri, 08 August 2014 13:54  |
Lu Cao
Messages: 77
Registered: February 2013
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continuous participant |
From: *ikp.kfa-juelich.de
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Dear PID experts,
I simulated 10 charged kaon in box generator with the momentum (1,4) GeV/c and checked the photon multiplicity in this K+ box like this:
---event loop---
theAnalysis->FillList(neu,"Neutral");
hgeve->Fill(neu.GetLength());
As shown in the attached .png, in the 10 evt K+, we got avg. 5.7 neutrals and 2 of those events got surprising 16 neutrals.
To understand this in a deeper level, Tobias helped to check the EMC cluster in MCTrack:
fMCMatch->CreateArtificialStage("MCTrack");
Int_t nCluster = fClusterArray->GetEntriesFast();
Int_t nTracks = fMCTrackArray->GetEntriesFast();
//loop to test Cluster
for (Int_t iCluster=0; iCluster<nCluster; iCluster++)
{
PndEmcCluster* theCluster = (PndEmcCluster*) fClusterArray->At(iCluster);
std::vector<Int_t> mcIndexes = theCluster->GetMcList();
for (Int_t iMcIndex = 0; iMcIndex < mcIndexes.size(); iMcIndex++){
std::cout << "Tracks in Cluster " << iCluster << " TrackId: " << mcIndexes.at(iMcIndex); // << std::endl;
PndMCTrack* myTrack = (PndMCTrack*)fMCTrackArray->At(mcIndexes.at(iMcIndex));
std::cout << " PdgCode: " << myTrack->GetPdgCode() << std::endl;
}
}
Then, we got this info:
Tracks in Cluster 1 TrackId: 0 PdgCode: 321
Tracks in Cluster 2 TrackId: 0 PdgCode: 321
Tracks in Cluster 3 TrackId: 0 PdgCode: 321
Tracks in Cluster 4 TrackId: 0 PdgCode: 321
Tracks in Cluster 5 TrackId: 0 PdgCode: 321
...
It looks some charged particles fired the EMC crystals but they are treated as "neutral candidates".
With best regards,
Lu
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Attachment: Canvas_1.png
(Size: 18.24KB, Downloaded 862 times)
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| Re: Charged Hits in Neutral List [message #17276 is a reply to message #17232] |
Wed, 10 September 2014 17:58  |
Shyam Kumar
Messages: 78
Registered: September 2012
Location: Mumbai, Maharashtra India
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continuous participant |
From: 103.21.126*
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Hi Lu,
I am also doing the same thing for the cut parameter optimization for Ftof, It will be useful in every case whichever algorithm I use. I have read in detail about it. I can give some idea what i understand stefano can tell whether it is correct.
Actually when a charged particle passes through medium and detector it deviates its actual trajectory (multiple scattering) so only from the actual hit it is very difficult to get the actual path. so kalman filter is used for this. It has three steps extrapolation, filtering, and smoothing. In the extrapolation we predict the theortical value and one is the measured hit on detector then in filtering we do the weighted mean of this to get kalman fitted value and then smoothing is used to get the true point.
So In my case Tof quality (as TofCut in all.par file) is the distance square of the measured position (actual hit) and extrapolated position(theortical predicted value) if it will be small then we will get the better result.
The all parameter is in all.par file https://subversion.gsi.de/trac/fairroot/browser/pandaroot/release/dec13/ macro/params/all.par (412-428). EmC quality should be Emc12Cut in all.par in line 418.
Thank you
Shyam
[Updated on: Wed, 10 September 2014 18:05] Report message to a moderator |
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| Re: Charged Hits in Neutral List [message #17277 is a reply to message #17276] |
Thu, 11 September 2014 09:23 |
Lu Cao
Messages: 77
Registered: February 2013
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continuous participant |
From: *lnf.infn.it
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Hi Shyam,
good to know the correlator with tof, but the situation is quite different with the case of emc. For a more detailed info on the emc issue, you can have a look at my slides which has been presented in the collaboration meeting: https://indico.gsi.de/conferenceDisplay.py?confId=2943
The problem we have now is not only parameter optimization, but deeper in the level of algorithm itself.
With best regards,
Lu
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