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correction in emc bump splitting [message #7669] Tue, 13 January 2009 04:10 Go to next message
Dima Melnychuk is currently offline  Dima Melnychuk
Messages: 213
Registered: April 2004
Location: National Centre for Nucle...
first-grade participant
From: 94.254.162*
Hi all,

I have corrected the small bug in emc code which affected bump splitting and particularly calculation of the bump position. (rev.4314)

The energy of the bumps was calculated properly but to suppress merged pi0, we need not only energies of the bumps but also opening angle of pi0. And the bug in the calculation of bump position resulted in wrong opening angle and as a result in low efficiency of the merged pi0 suppression.

The pictures below gives some demonstration of the bump splitting for 200 event, 5 GeV pi0 generated in [30;60] degree theta range.

The following picture presents the MC Truth energy of gamma's from pi0 decay and reconstructed energy of EmcClusters.

index.php?t=getfile&id=4903&private=0

The same for EmcBumps
index.php?t=getfile&id=4904&private=0

i.e. the energy distribution is reproduced.

The opening angle of pi0 for MC Truth and EmcClusters
index.php?t=getfile&id=4905&private=0

And reconstructed opening angle for EmcBumps
index.php?t=getfile&id=4906&private=0


And finally pi0 invariant mass for EmcClusters
index.php?t=getfile&id=4907&private=0
and EmcBumps
index.php?t=getfile&id=4908&private=0
i.e. without bump splitting only 10 % of pi0 are reconstructed.

All the pictures are plotted with bump_analysis.C macro.

Best regards,
Dima
Re: correction in emc bump splitting [message #7671 is a reply to message #7669] Tue, 13 January 2009 15:54 Go to previous messageGo to next message
Bertram Kopf is currently offline  Bertram Kopf
Messages: 110
Registered: March 2006
continuous participant
From: *ep1.ruhr-uni-bochum.de
Hi Dima,

great! So my question to you and especially to Irina: Is it now possible to obtain reasonable results for the gamma gamma studies which should go to the Physics Book?

Best regards,
Bertram.
Re: correction in emc bump splitting [message #7674 is a reply to message #7671] Tue, 13 January 2009 23:16 Go to previous messageGo to next message
Johan Messchendorp is currently offline  Johan Messchendorp
Messages: 693
Registered: April 2007
Location: University of Groningen
first-grade participant

From: *xs4all.nl
Dear all,

I am re-running the analysis part of the simulations for the gamma gamma studies at the KVI.... with the latest revision. This should not take too long, since I am only re-running a part of the simulation.

Johan.
Re: correction in emc bump splitting [message #7847 is a reply to message #7674] Fri, 06 February 2009 12:58 Go to previous messageGo to next message
Irina Brodski is currently offline  Irina Brodski
Messages: 8
Registered: October 2008
occasional visitor
From: *physik.uni-giessen.de
Dear all,

this correction improved the bump splitting for pi0-events, but i still have a problem with gamma gamma events and there is still a factor of 2-5 for the background above 3 GeV to suppress.
Here a little macro to explain.


Please please run it with:
root -l "Fehlersuche.C(\"gammagamma.root\",7.5298 )"
root -l "Fehlersuche.C(\"pi0pi0.root\",7.5298 )"

Many single gamma-clusters in the shashlyk are split in two.
Maybe someone can help me?
Thank you,
Irina
Re: correction in emc bump splitting [message #7848 is a reply to message #7847] Fri, 06 February 2009 13:46 Go to previous messageGo to next message
Dima Melnychuk is currently offline  Dima Melnychuk
Messages: 213
Registered: April 2004
Location: National Centre for Nucle...
first-grade participant
From: *fuw.edu.pl
Hi Irina,

Small correction to your post. From the data file gammagamma.root it looks like that some single gamma clusters are split into 2 bumps not in shashlyk but in forward endcap (slightly above 2 meters in Z direction) and there is no single event with clusters in shashlyk.

And it looks like that problem is related with what Bertram posted http://forum.gsi.de/index.php?t=rview&goto=7833#msg_7833

I tried to solve it but still without success.

Dima
Re: correction in emc bump splitting [message #7850 is a reply to message #7848] Fri, 06 February 2009 15:05 Go to previous messageGo to next message
Bertram Kopf is currently offline  Bertram Kopf
Messages: 110
Registered: March 2006
continuous participant
From: *ep1.ruhr-uni-bochum.de
Hi Irina and Dima,
just one additional remark:

Dima Melnychuk wrote on Fri, 06 February 2009 13:46

Hi Small correction to your post. From the data file gammagamma.root it looks like that some single gamma clusters are split into 2 bumps not in shashlyk but in forward endcap (slightly above 2 meters in Z direction) and there is no single event with clusters in shashlyk.

And it looks like that problem is related with what Bertram posted http://forum.gsi.de/index.php?t=rview&goto=7833#msg_7833



Due to the fact that only events with |cos(Theta*)|<0.6 are considered, the shashlyk detector doesn't contribute at all. The reconstructed gamma hists either the barrel calorimeter or the forward endcap. The backward endcap is also important in order to see low energetic gammas originated from the pi0 background.

Best regards,
Bertram.
Re: correction in emc bump splitting [message #7879 is a reply to message #7850] Fri, 13 February 2009 22:33 Go to previous messageGo to next message
Irina Brodski is currently offline  Irina Brodski
Messages: 8
Registered: October 2008
occasional visitor
From: *dip0.t-ipconnect.de
Yes, Bertram is right. I mean the detektor part on a position of >200. This should be the endcup
Re: correction in emc bump splitting [message #7929 is a reply to message #7669] Thu, 19 February 2009 21:48 Go to previous message
Johan Messchendorp is currently offline  Johan Messchendorp
Messages: 693
Registered: April 2007
Location: University of Groningen
first-grade participant

From: *xs4all.nl
Hi,

I started a new series of simulations with the older forward endcap design, as we discussed this afternoon. The jobs are in the queue. For Irina, the results will appear at kvip81 (once the jobs start running, though) at the location:

/daq/panda/simgg_feb09/....

Kind wishes,

Johan.


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