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TCut cut = "TMath::Abs((acos(Tkr1ZDir)*(180./3.14159))-180.) < 5 && CalEnergyRaw>10";
Philippe also shown very broad distributions of CalTransRms in past VRVS beam test meeting (2006/08/01). Yet the origin of this broad distributions seems NOT to be related to the effect which is described above. I do NOT see this effect in the events from run 700000811. Details of this analysis can be found inQuickLookToEventsFromRun700000811.
The images ElectronWithCU_1 and ElectronWithCU_2 show the distribution of energy deposited in the calorimeter when a electron goes through it. This is a NOT a typical image in run 811. Typically this run shows many events with more than one charge particle in the Calibration Unit. Therefore, these images with only one clean track have been carefully selected. The goal here is not to show a typical image, but to check whether the effect described previously occurred in run 811; and for that one needs events with only 1 electron traversing the calorimeter.
Note that the track of the electron in the calorimeter does not have the "holes" showed for the muon events from runs 460 and 322. Images ElectronWithCU_2_ZX ElectronWithCU_2_ZY show the second electron event from the ZX and ZY perspective. The track is well defined in both planes.
The distributions of the variables Trk1ZDir and CalZDir are shown in Electron811Reconstruction.gif, Electron811Reconstruction.ps and Electron811Reconstruction.root (gif, ps and root files). And the distribution of the variable CalTransRms is shown in Electron811CalTransRms.gif, Electron811CalTransRms.ps and ElectronCalTransRms.root. Note that the reconstruction fo these variables is not as "incorrect" as in the case muons events from runs 460.
Therefore, it seems that run 811 is NOT suffering from the calibration problem described before.
The differences in CalZDir and, specially CalTransRms observed in run 811 seem to have their origin in the presence of other charge particles (in addition to the 5 GeV electron) in the Calibration Unit. Scanning events from this run with FRED, one finds many events with more than 1 clear charge particle entering in the tracker of the Calibration Unit.
Typical images from run 700000811 with more than one incoming charge particle can be found HERE.