# Presentation: 380709

## Software and Performances

- H.Ma, G.Unal
- LAr week
- 27/09/2007

## Releases

- Release 12:
- Used for CSC simulation and now for CSC physics analysis. Closed
- Note: Event duplication issue in CSC productions
- 12.0.95 for Geant 4.8.2 CTB simulation.
- Release 13:
- 13.0.25/13.0.26 for M4 week
- 13.0.30 done this week. No further 13.0.X planned (except problem). Bug fixing in 13.0.30.X production cache.
- Aims:
- Reconstruction of release 12 simulations
- Priority on material for Atlas detector paper
- Validation of Geant 4.8.3 simulation
- Difference physics list QGSP_EMV, QGSP_BERT
- Frozen showers
- Note that rel 13 has a lot of edm changes/improvements compared to 12

## Release 14:
Aimed for end 2007/beginning 2008
Increased robustness and consolidation

- Aimed for end 2007/beginning 2008
- Increased robustness and consolidation

## Software validation

- Suite of tests (ATN,RTT) running calorimeter simulation,digitization,reconstruction on various samples every day on different release branches
- To catch
- Compilation errors
- Crashes
- Memory leaks
- Error messages
- Incorrect results through histogram comparison for some tests
*Karim & Helenka are LAr contacts in Atlas “technical” validation run by M.Gallas*

- Karim

## Software documentation

- Review in July
- Work on edm and main algorithms documentation before the review
- Action item list from the review:
-  _[https:](https://twiki.cern.ch/twiki/bin/view/Atlas/DocManRev07Calo)__[//twiki](https://twiki.cern.ch/twiki/bin/view/Atlas/DocManRev07Calo)__[.](https://twiki.cern.ch/twiki/bin/view/Atlas/DocManRev07Calo)__[cern](https://twiki.cern.ch/twiki/bin/view/Atlas/DocManRev07Calo)__[.ch/twiki/bin/view/Atlas/DocManRev07Calo](https://twiki.cern.ch/twiki/bin/view/Atlas/DocManRev07Calo)_

## Simulation G4 hadronic physics 

- Presentations by Tancredi and Andrei yesterday
- Recent changes / improvements in hadronic physics
- Still trying to have a coherent picture of the “best” way to simulate all Atlas calorimeters (EM, HEC, Fcal, Tile)
- Maybe more CPU intensive
- Simulations with different physics list in release 13 should also give us a feeling on the sensitivity of jet calibration, missing Et, etc..

## Hadronic Physics in G4

- Physics List: mix of models configurable for particle and energy:

**QGSP: **theory driven model for E>20 GeV:
-              Quark Gluon String Pre-compound
**LHEP:**    parameterisation of data (~old Geisha)
**QGSP_BERT: ** QGSP + Bertini cascade (nucleon-nucleon scattering)
**QGSP_BIC: **     QGSP + Binary cascade

- usable in G49

*Tancredi*

## Pion Longitudinal Shower in TileCalComparison G47 vs G483 

- Pion Longitudinal Shower in TileCalComparison G47 vs G483

- New Geant4 version has longer showers due to quasi-elastic scattering
- Good agreement with data for pions

- G47

- G483

- -3-5%

- ~25%

*Tancredi*

## Combined Barrel Test-Beam – Topo Cluster Moments

- E=180 GeV

- Energy density of highest topo cluster

- 2nd moment of radial shower of highest topo cluster

- QGSP

- QGSP_BERT

- QGSP_BERT

- QGSP

- Moments used in cluster classification of local hadron calibrations
- Moments describe shower topology  Important for particle ID

- G47

*Tancredi*

## Pion Resolution TileCal

- G47

- G483

- QGSP gives better resolution in G483 than in G47
- Resolution better described with Bertini in G47, G483, G49

*Tancredi*

## Andrei

*Andrei*

## So far so good for QGSP_BERT, But...

*Andrei*

## Andrei

*Andrei*

## Things to explore

- Timing structure of hadronic shower
- Effect shown to be small for EM (~1%)
- Large effect in Tile (~10%) correctly taken into account in CTB simulation
- Effect in HEC test-beam simulation ?
- Energy deposit by low energy neutrons
- Not all energy is converted to ionization
- Effect negligible for EM, but maybe not for hadronic calorimeters (?)
- Or it is really something in the G4 physics related to different materials (Iron vs Copper)

## Tancredi’s Conclusion

- On long term we have to move to QGSP with cascade model
-     (Bertini or BiC or combination) and we should use G49
-      +) better radial shower description (TileCal, CTB)
-      +) better longitudinal shower description (TileCal, HEC)
-      +) better resolution in TileCal
-      +) better linearity in TileCal
-      -)  problems in response and resolution in HEC
-  *(and also in E(Lar middle) in CTB)*
- Should test the various
-      new physics list available in G49 (e.g. Fritjof, Bertini tuning)
-  Need to discuss with G4 people why G483 bit different than G49
- Need to investigate apparent discrepancy between Lar (Barrel/HEC?) and Tile ?
- “I am quite confident that we are on a good way to have a much better MC
- than we had for a long time. There is real progress and I consider
- the remaining problems as details !”

## Simulation: frozen showers

- Joe

## Various iterations to optimize frozen showers:

-  One example: Choice of eta binning of EMEC

## (few variables like phi modulation are probably difficult to reproduce)

- (Calo is ~50% of total CPU time after frozen showers)

## Performance section of ADP

- Presentations this week at the e/gamma meeting and at the calo perf meeting
- E/gamma outline:
- Energy and position resolutions from calorimeter
- based on release 12 calibration work
- Electron and Photon identification
- Basics performances (eff vs Rejection)
- Tools for in-situ studies
- Mostly indicate statistical power to various tools like Z intercalibration

## Jet outline:
Jet algorithms
Kt,cone,..
Input to jets
Cells, Clusters, impact of noise
Jet calibration
Cell weighting method
Jet signal characteristics
Single pion response
Jet response (resolution, linearity, uniformity)
In-situ calibration
Jet reconstruction performances (eff, purity)
Etmiss outline:
Fake Etmiss Reconstruction and calibration of Etmiss 
Noise effect, calibration, muon contribution, cryostat contribution
Evaluation of Etmiss performances
Etmiss direction
Etmiss in mass reconstruction

- Jet algorithms
- Kt,cone,..
- Input to jets
- Cells, Clusters, impact of noise
- Jet calibration
- Cell weighting method
- Jet signal characteristics
- Single pion response
- Jet response (resolution, linearity, uniformity)
- In-situ calibration
- Jet reconstruction performances (eff, purity)
- Etmiss outline:
- Fake Etmiss Reconstruction and calibration of Etmiss
- Noise effect, calibration, muon contribution, cryostat contribution
- Evaluation of Etmiss performances
- Etmiss direction
- Etmiss in mass reconstruction

## Calo CSC notes

- Csc-1: Clustering algorithms *(**S.Laplace)*
- Partially written, performance part to complete, aim to progress for october software week
- Csc-2: hadronic calibration *(P.Schacht)*
- Lot of recent work on this topic, but take some time to write
- Csc-3: Misalignment *(R.Zitoun)*
- First study done by R.Zitoun with first draft, to be updated
- Csc-4: Simulation *(J.Boudreau)*
- ~100 pages draft circulated among experts, need to add something on charge collection in EMEC +  revisit Fcal section
- Csc-5: Digitization *(G.Unal)*
- Noise and Pile up simulation in release 12. Submitted