LAT Newsletter contributions from Beam Test Team
Issue 4 - submitted 31 may
Luca Latronico
May 31 2007
The Calibration Unit worldwide tour was successfully concluded in the beginning of April, when the module was sent to SLAC and handed off to ISOC-SO that will turn it into a test bed to for studying flight hardware response to flight software.
This was the last step of a successfull series of CU operations carried on by the beam test team since its first integration just about one year ago .
We are happy to deliver such a valuable instrument to the ISOC, and completion of data analysis is now our only target.
On this ground, three main activites were pursued during the last month:
- re-evaluation of data-MC discrepancies after the last data reprocess and updates to the simulation
- completion of the standalone single-tower simulation and comparison with our standard Gleam MC
- systematic exploration of available hadronic physics lists
The most recent changes to our simulation/reconstruction package (BTRelease) include the adjacent crystal cross-talk correction for the calorimeter energy measurement, two alternative Tracker digitization algorithms with description of charge sharing and large signal cross-talks, and a correct use of the tracker calibration database.
These last improvements did not significantly change the data/MC discrepancy in the CAL and in the number of tracker hits, but provide an accurate description of the measured ToT distribution.
The standalone Geant4 simulation was completed with a realistic tracker tray honeycomb description, as opposed to a density-averaged homogeneuous material. No effect was observed in the total number of hits and in the EM shower development, which is also very similar to the one produced by Gleam. Our conclusions are that Gleam and a standalone Geant4 simulation generate similar EM shower profiles, and a more realistic tray description does not solve the CAL or TKR discrepancy.
haronic physics: more thourugh study. suggested hadronic physics list now Bertini up tp 10GeV,l QGSP above 20GeV.
Issue 3 - submitted 30 april
Luca Latronico, Philippe Bruel
April 30 2007
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