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EMC deposit energy for electron
https://forum.gsi.de/index.phpindex.php?t=rview&goto=24125&th=6765#msg_24125
attached is the deposit energy of the electron in the EMC as a function of the polar angle in the lab frame (from the simulation of ppbar->e+e- at p=3.3 GeV/c using the pandaroot "dev").
There is a problem of the deposit energy in the region between 18 and 22 degree (also present in dec18 versions). By removing the following cut in pid/PidCorr/PndPidEmcInfo.cxx:
[if ((emcModule == 3) && (helix->GetZ() < 165.)) continue; // consider tracks only from last gem plane for FWD]
The problem is partially solved in the region between 20 and 22 degree.
This drop of deposit energy decreases the efficiency of our signal from the EMC pid cuts.
Does anyone know how to solve this problem which was not present in old PANDA versions?
Thank you in advance and best regards,
Alaa]]>dbeyssi@ipno.in2p3.fr2019-06-23T17:16:06-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=23059&th=6343#msg_23059
If I consider those cases in which the particle of interest was reconstructed but at least one photon did pair production as background, I lose a huge fraction of my signal.
If I consider those cases as signal, I certainly have a systematic error I have to correct for (maybe some sort of energy-correction based on the multiplicity in an event?)
Thanks for your help!
Christian]]>Christian Will2018-10-10T08:45:47-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=23010&th=6343#msg_23010
your EMC clusters have FairLinks pointing to the MC track they were created from. If more than one particle contributed to your cluster you will have a list of FairLinks pointing to all initial particles which deposited energy in the cluster.
You would iterate through all your clusters and check the MC-Id if it matches with your primary photons. If they match you are done. If they do not match you have to take the MC track belonging to the MC Id and ask for its mother Id. You check if the mother is your photon, if not you continue until you either have a matching photon or not.
Cheers,
Tobias]]>Tobias Stockmanns2018-10-02T12:21:32-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=23007&th=6343#msg_23007
If the MC-match of my particle of interest is not correct, I iterate through all 7 gammas and check if they are actually a e+ or e- according to MC. If yes, I walk the decay tree up starting from this particle and check if at some point a mother particle is a gamma of my original decay tree.
Also, a follow-up question which came to my mind: which MC-id does a candidate receive that is reconstructed as one particle but actually consists of two particles which cannot be resolved?
E.g. a gamma as reconstructed particle in the EMC which was actually a high-momentum e+e- pair (without tracks).
Thanks so far,
Christian]]>Christian Will2018-10-02T12:05:42-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22997&th=6343#msg_22997
Only case 1 needs the iteration backward to the original mother particle.
Cheers,
Tobias]]>Tobias Stockmanns2018-10-02T11:22:12-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22990&th=6343#msg_22990
But how can I distinguish between the two cases
1) a photon did pair production before hitting the EMC (no tracks of e+e-)
2) a photon did pair production as the first interaction when showering in the EMC ?
]]>Christian Will2018-10-02T11:11:20-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22982&th=6343#msg_22982
I support the statement of Ralf. The MC information in the EMC points to the particle which first entered the crystal but you have a lot of material in front of the EMC with a high probability that the photons make pair production.
Cheers,
Tobias]]>Tobias Stockmanns2018-10-01T09:12:39-00:00Re: MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22980&th=6343#msg_22980
I suggest you do the MC matching not only with the directly derived MC particle, but iterate through the mother/daughter relations until you find the proper match or a proper mismatch.
Cheers!
Ralf]]>Ralf Kliemt2018-10-01T09:06:38-00:00MC-truth match in a 7-photon final state
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22975&th=6343#msg_22975
I am doing simulations of a decay tree including a hybrid candidate which has 7 photons (and an e+e- pair) as final state. As you may know, in the current PandaRoot implementation there is quite a high probability that a photon interacts (compton-scattering, pair-production, ...) before it creates an electromagnetic shower in the EMC. As a result, in my channel only in a tiny fraction of events none of the seven photons have interacted before showering. This is problematic for me because when I check my reconstructed hybrid candidate for Monte-Carlo truth matches, the number of MC-matches is very low. I currently assume(!) that the low number of MC-matches is caused by the fact that when one of the photons interacts before showering, the reconstructed decay tree does not match the decay tree for my hybrid candidate and the MC-match returns "false". This leads to the problem that I can't optimize my parameters because I can't determine what is signal and what is background properly.
Has anyone experienced similar issues and found a workaround or can at least confirm my assumption about the MC-matching?
Cheers,
Christian
(Giessen University, Germany)]]>Christian Will2018-09-28T11:22:13-00:00Re: Geant Information
https://forum.gsi.de/index.phpindex.php?t=rview&goto=22209&th=5994#msg_22209
The thing is, that I can not reconstruct kaons with a momentum below 200 MeV, so I wanted to take a look a the stop vertices of the generated monte carlo truth track, to see where my kaons go. I found start vertices in the MCTrack objects but unfortunately no stop vertices. What do you mean by "often"? Are there any requirements for the creation of such a "Point"? And can I get information about what is happening in the beam pipe, because these "Points" are just created by detectors.
Thank your for your help.
Iman]]>Iman Keshk2018-02-15T08:37:16-00:00