Progress report on Calorimeter design comparison simulations

1. Progress report onCalorimeter design comparison simulations MICE detector phone conference 2006-01-27 Rikard Sandström

2. Before I begin: Scraping in trackers • At 6 pi mm, partial scraping in trackers. • Particles still make it through the experiment. • Manually filtering events with more than 7 MeV energy loss in a tracker. • Done by using MC truth values. • Tracker people will have to deal with this.

3. Outline • The alternative detector geometry • Techniques and methods used • PID simulations in 14 steps • Present status • Results so far

4. The alternative calorimeter • The alternative calorimeter consists of one KLOE light layer in front, then ten plastic layers. • Used to call this smörgås, sandwich has two KLOE layers. The latter is no good idea, so sandwich now means the variant with only one KL layer. • Plastic layers contain 9 cells each, at increasing thickness. (1 cm to 12 cm). • Increasing thickness gives best range(p) resolution for money. • Total number of channels is constant between designs. • KL: 4x30x2 = 240 channels. • SW: (30+10x9)x2 = 240 channels. • Abbreviations: • KL = KLOE Light (4 KLOE Light layers) • SW = Sandwich (1 KLOE Light layer, then plastic)

5. Reminder of run plan • Stage 1 • Pi & Mu • 100<pz<300 MeV/c • Stage 6 • Mu & mu-decay • 140 MeV/c • 170 MeV/c • 200 MeV/c • 240 MeV/c • Tilley’s TURTLE beam, with diffuser

6. Method #1 (examples follows) • Write a document explaining what to do and why • Not in the document = not on the table. • Simulate beams of 10k events, wide distributions. • Use those to find useful variables for PID. • Find combinations of detectors, such that given A, expect B. • Make fits for all expected values, and create “discrepancy variables” 1-expected/measured. • Zero means very muon like. • Run 120k events of muons per experimental scenario. • ~ 2Gb of data per file • For every such scenario, also run 120k muons with 40 ns lifetime to generate background. • Muons not decayed at TOF2 are filtered out of analysis.

7. Method #2 (examples follows) • Digitize every simulated beam. • Convert to ROOT trees, and tag good/bad event. • For every scenario, merge the muon sample with the background sample. • Filter out events while trying to not lose any muons. • Train a Neural Net on the half of the merged & filtered sample (training sample). • Using the weights acquired by Neural Net, assign a weight all other events (the test sample). • Evaluate the PID capabilities by looking at weights for the test sample.

8. 100<pz<300 MeV/c

9. Sandwich 100<pz<300 MeV/c

10. Example of a fit

11. Example of “discrepancy variable” used for Neural Net Discrepancy = 1-expected/measured

12. Discrepancy = 1-expected/measured

13. Stage 1, 100<pz<300 MeV/c

14. Stage 6, 140±14 MeV/c

15. Stage 6, 170±17 MeV/c

16. Stage 6, 200±20 MeV/c

17. Stage 6, 240±24 MeV/c

18. Stage 6, Tilley’s TURTLE beam • A problem with the diffuser does not allow it to be placed. • Without a diffuser, too low emittance. • If I have time I will try to solve the problem before Japan.

19. Bug 107 • A vector in EmCalHit holding pointers to EmCalDigits seems to be corrupt. • Very rare makes it hard to debug. • Why rare? • Since the RootEvent converter uses the same class both Digitization and RootEvent suffers. • Could be compiler/machine specific problem. • Then move all files to another computer, but we are talking of ~ 50 Gb of data.

20. Results - Stage 1 KLOE Light • Neural Net • For training, used only muons which stayed muons until downstream TOF or beyond. • Same for pions. • For testing, pions decaying to muons between TOFs where • treated as background. • omitted from analysis. • KLOE Light: • Strongest variables are based on: • tof, barycenter, and fraction of energy in first layer. • Sandwich: • Strongest variables are based on: • tof, barycenter, and total energy in calorimeter Sandwich

21. Results - Stage 6 • Only 140 MeV/c, KLOE Light is finished. • Results are very promising, but I wait with presenting them until I can compare the different detectors.

22. Comments • All momentum and tof measurements are MC truth. • Still waiting for tracker reconstruction to come back online. • For tof, might simply add a Gaussian.

23. Summary • Stage 1 is finished • Only a matter of how to present it. • Most of stage 6 is simulated, but only partly digitized. • A bug most be fixed to continue. • The first stage 6 beam that could be analyzed looks promising.