Page History

LAT Newsletter contributions from Beam Test Team

Joint report with C&A on the C&A-SciOps workshop

Simulation highlights

BT simulations were successfully ported to the Pipeline II environment by Johan; this ensures a consistent platform with other LAT simulations for data generation, archival and storage, which will allow efficient use of the BT data well after launch. A number of test simulations are now available from the data catalog, and any new simulation will be generated using Pipeline II.
the H4 line simulation was double-checked and updated by Francesco as to extend the simulation up to the last bending magnet in the line. No significant difference was found in the energy distribution
a comprehensive comparison with EGS5 from David showed very good agreement with Geant4
scaling variables: we started looking into ways for scaling the MC data to match our data; Johan explored the consequences of changing CAL calibration constants, Luca scaled the ntuple variables and started looking at consequences of the scaling in the event classification, Carmelo showed the consequences of changing the incoming beam energy by the measured discrepancy. We will have further discussions on this topic in the CA-SO workshop in Bari, and plan to agree on a way to implement this

Analysis highlights

bad position measurements in the CAL were studied by Philippe and Sasha; a possible explanation for these could be event pile-up, but it requires some more analysis to be confirmed
TKR cuts are being revised in the light of the new variables introduced for the neutral energy events
LAC thresholds behave in a different way in data and simulation : potentially due to pedestal drift, issue is under investigation

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pass5 variables from the current event classification analysis are added to the Merit Tuple and replace old pass4 variables; this allow a subsystem specific data-MC comparison for the relevant variables for background rejection
vertex variables in the tuples are modified to describe also neutral energy events; this requires a thorough check of the usual TKR cuts that were used so far in the TKR analysis, and in particular Tkr1 variables should replace Vtx variables for analysis of all charged tracks
list of golden runs : we are adding some new reference runs after we discovered that many of the runs we used are showing a weird structure in the TkrYdir_vs_TkrY correlation plot as a consequence of a large dead area in plane 35 of Tower 2 that the beam crossed and noisy strips around that area
a pressure scan in the cerenkov detectors along the SPS H4 line was performed as a quick way to simulate effects of different material along the line
the high energy SPS runs (E>5GeV) were re-simulated with the correct pressure (0.1bar) and gas (He) in the cerenkov detectors along the H4 line
along with moving to v71215p0, synchronized with GR v12r15, Beamtest MC software is going to be updated to run on the pipeline II, in particular to use the new standard ways to store data on xroots and access them via the data catalog.

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