In this page you can find FRED images of events from run 700000811 in which there are more than 1 clear incoming charge particle.
The events were filtered before running FRED by the following cut:
char* cuts = "TMath::Abs((acos(Tkr1ZDir)*(180./3.14159))-180.) < 5 && CalEnergyRaw > 10";
FRED images are linked below:
Evt3, Evt5, Evt6, Evt7, Evt9, Evt10, Evt11, Evt12, Evt13
The events are "selected" to have more than one clear incoming particle, yet it is important to note that these are not rare events.
They occur very often in that run; out of the first 13 events, 9 events have more than 1 clear incoming charge particle.
These events deteriorate the reconstruction of the incoming direction in the calorimeter (CalZDir) and broaden the distribution of CalTransRms, as shown by Philippe in the VRVS meeting from August 1st.
It is perhaps interesting to discuss 2 of the previous images.
In Evt9, one can notice that the hits distribution in the tracker is consistent with 3 charge particles; yet only 2 tracks are recongnized. It is worth noticing that the energy deposition in the calorimeter is about 3 cm off the two selected tracks. Therefore, it is probable that the incoming electron is the track which is NOT recognized by the reconstruction program, and the two tracks which are recognized and marked in the tracker are pions or muons; which produce very little signal in the calorimeter.
In Evt12 one can note that the incoming direction reconstructed in the calorimeter is screwed by energy depositions which are away from the main shower.
I also happen to meet an interesting event which i could not understand so far; that is Evt18.
In this event there are 3 (!!!!) recognized tracks (with reconstructed energy 4.8, 2.5 and 1.5 GeV). The hit distribution in the tracker might suggest the presence of more than 3 charge particles.
I linked 3 2-views FRED images of this event. In each of the 3 images i selected one of the 3 recognized tracks, so that one can see the corresponding track in each other view:
I still do not understand why the main track (the one with 4.8 GeV) is not aligned (Tracker-Calorimeter)
in the YZ view. Any idea ?