1. 19 July 2005Fabrizio Cei1 Status and Perspectives of MEG software Fabrizio Cei INFN & University of Pisa On behalf of the MC/Offline group MEG Review Meeting PSI, 19 July 2005

2. 19 July 2005Fabrizio Cei2 Outline  MC status and perspectives  Offline status, perspectives and milestones and milestones  Rough Estimates of CPU/data storage needs storage needs Contributions: Tokyo, Pisa, Lecce, PSI, Roma and Pavia groups. Tokyo, Pisa, Lecce, PSI, Roma and Pavia groups.

3. 19 July 2005Fabrizio Cei3 MC status & perspectives MEGEVE - Event Generator MEGEVE - Event Generator GEM – The detector simulator GEM – The detector simulator – Liquid Xenon Calorimeter – Drift Chamber – Timing Counter – Magnet and Target ZEBRA Output and Analysis Tools ZEBRA Output and Analysis Tools LP/Beam Test fully simulated (not discussed) LP/Beam Test fully simulated (not discussed) Contributors : S. Yamada, P. Cattaneo, F. Cei, W. Ootani, H. Nishiguchi et al. S. Yamada, P. Cattaneo, F. Cei, W. Ootani, H. Nishiguchi et al.

4. 19 July 2005Fabrizio Cei4 Energy release in LXe Positron track Hits on TC

5. 19 July 2005Fabrizio Cei5 MEGEVE: the event generator StatusStatus –Signal events –Michel positrons –Radiative decay Exact formulae for unpolarized muonExact formulae for unpolarized muon Approximation for polarized muon (back-to-back, P e  P   52.8 MeV)Approximation for polarized muon (back-to-back, P e  P   52.8 MeV) –AIF Preliminary AIF within targetPreliminary AIF within target Started study for realistic AIF: magnet, DCH, TC and TargetStarted study for realistic AIF: magnet, DCH, TC and Target –Scheme to generate pile-up events (Michel + RD, Michel + AIF, AIF + RD, RD + RD) + additional(Michel + RD, Michel + AIF, AIF + RD, RD + RD) + additional Michel decays; more than two events can be overlaid Michel decays; more than two events can be overlaid time difference distribution inserted: flat with user-defined rangetime difference distribution inserted: flat with user-defined range NextNext –Exact formulae for polarized muon’s radiative decay –Realistic AIF and background studies (under way) –Estimate disk space requirements for MC –Study of online (or semi-online ?) pre-selection and calibrations –...

6. 19 July 2005Fabrizio Cei6 Background studies under way 1) Accidental background from superimposition of a Michel positron and a  from radiative decay. Simulation of trigger conditions quoted in the Proposal – Photon energy cut E  > 45 MeV – Time window e + -  △ T = 10 ns – e + -  direction matching Preliminary Work E (MeV) (Y. Hisamatsu et al.)

7. 19 July 2005Fabrizio Cei7 Background studies under way 2) Realistic studies of Michel positron annihilation in flight. Almost complete detector simulation (not the target only) Main contributions from target and drift chambers. Annihilation  energy spectrum in LXe Preliminary Work (H. Nishiguchi)

8. 19 July 2005Fabrizio Cei8 Detector simulation 1) LXe StatusStatus –Geometry revised shape for vacuum vessel, PMT holders and honeycombrevised shape for vacuum vessel, PMT holders and honeycomb –Implemented decay curve of Liquid Xenon Scintillation –GEANT based ray tracking Reflection on PMT quartz window and PMT holdersReflection on PMT quartz window and PMT holders PMT quartz window transmittancePMT quartz window transmittance Absorption and scattering in Liquid XenonAbsorption and scattering in Liquid Xenon –Outputs Energy deposit, position and timing in Liquid XenonEnergy deposit, position and timing in Liquid Xenon Preliminary waveform output: hit timing of scintillation photonsPreliminary waveform output: hit timing of scintillation photons for each PMT ( ～ 3 x 10 4 photoelectrons) for each PMT ( ～ 3 x 10 4 photoelectrons) NextNext –Update geometry to match the final design –Implement support structure –“Fast” scintillation photon tracking; multiple options ? (GNEXT/hand made)

9. 19 July 2005Fabrizio Cei9 Detector simulation 2) DCH StatusStatus –Geometry Helium bag turned off by defaultHelium bag turned off by default Implementation of the Vernier padImplementation of the Vernier pad –Isochrones tables for various B-field –Outputs Entrance/Exit position from cellsEntrance/Exit position from cells Energy, timing and direction for each hitEnergy, timing and direction for each hit Digitized hit timing, charge on wireDigitized hit timing, charge on wire Drift time in cellsDrift time in cells NextNext - Update geometry for latest DCH support and peripherals - Update geometry for latest DCH support and peripherals - Implement charge simulation on both ends & Vernier pads - Implement charge simulation on both ends & Vernier pads effects on output signals effects on output signals - Implement pulse simulation on wires and pads - Implement pulse simulation on wires and pads

10. 19 July 2005Fabrizio Cei10 Detector simulation 3) TC StatusStatus –Geometry scintillation bars/fibers, PMTs, APDs and light guidesscintillation bars/fibers, PMTs, APDs and light guides –Outputs Hit position, timing and energyHit position, timing and energy Energy release and step length for each GEANT hitEnergy release and step length for each GEANT hit Preliminary waveform outputs for scintillation barsPreliminary waveform outputs for scintillation bars –Photon propagation inside the  -bars recently implemented NextNext –Implement support structure –Waveform for scintillation fibers - A standalone MC for comparison with scintillation bar beam test

11. 19 July 2005Fabrizio Cei11 Detector simulation 4) Target and Magnet StatusStatus - Preliminary approach outside GEM - Preliminary approach outside GEM - Realistic treatment of target geometry included in GEM - Realistic treatment of target geometry included in GEM NextNext –Implement target support –Beam transport within the detector

12. 19 July 2005Fabrizio Cei12 ZEBRA Output & Analysis Tools HitsHits –Energy deposit, position and timing for LXe/DCH/TC –Scintillation photon hits for LXe PMT Preliminary waveform outputPreliminary waveform output - Brute force approach: record all hit timing for each PMT (LXe) - Brute force approach: record all hit timing for each PMT (LXe) 3 x 10 4 photons @ 500 PMTs/828 PMTs for 52.8 MeV gamma 3 x 10 4 photons @ 500 PMTs/828 PMTs for 52.8 MeV gamma ⇒ 120 kB/event (w/ zero suppression); few kB/event from TC; ⇒ 120 kB/event (w/ zero suppression); few kB/event from TC; - Need binned waveforms to save disk space - Need binned waveforms to save disk space Event cocktail (MC & Data)Event cocktail (MC & Data) - Prototype for “Bartender” based on ROME in progress - Prototype for “Bartender” based on ROME in progress Analysis toolsAnalysis tools - ZEBRA2NTUPLE - ZEBRA2NTUPLE - ZEBRA2ROOT – based on ROME; temporary software waiting for MegRoot - ZEBRA2ROOT – based on ROME; temporary software waiting for MegRoot

13. 19 July 2005Fabrizio Cei13 The MEG “Bartender” 1) Read experimental and simulation data. Read experimental and simulation data. Make mixture of several MC sub events. Make mixture of several MC sub events. Simulation of pulse shape of MC data. Simulation of pulse shape of MC data. Rearrange channels of experimental data to make them as MC. Rearrange channels of experimental data to make them as MC. Simple calibration could be done. Simple calibration could be done. Trigger simulation could be done. Trigger simulation could be done. (R. Sawada)

14. 19 July 2005Fabrizio Cei14 The MEG “Bartender” 2) += Nphe = 620 Nphe = 123 Nphe = 743 Example: waveform pile-up  three possible models of single waveform;  gaussian, sinusoidal or constant noise can be added;  event rate can be specified;  relative timing is extracted randomly.

15. 19 July 2005Fabrizio Cei15 Offline status  MegRoot - First version recently released - Backbone is from AliRoot - Copyrights issues solved with F. Carminati - Included algorithms: Alice, GEM or proprietary - 4 Modules, 344 Classes, > 4000 Methods  Other topics - Promising pattern recognition and tracking - Promising pattern recognition and tracking algorithms under development (not discussed) algorithms under development (not discussed)

16. 19 July 2005Fabrizio Cei16 Contributors Main Architecture: Alice collaboration, V. Di BenedettoMain Architecture: Alice collaboration, V. Di Benedetto Magnet: E. Cavallo, W. OotaniMagnet: E. Cavallo, W. Ootani DCH: C. Chiri, F. Ignatov, M. Schneebeli, S. Spagnolo,DCH: C. Chiri, F. Ignatov, M. Schneebeli, S. Spagnolo, G. Tassielli, H. Nishiguchi G. Tassielli, H. Nishiguchi LXe: V. Di Benedetto, S. Mihara, R. Pazzi, R. Sawada,LXe: V. Di Benedetto, S. Mihara, R. Pazzi, R. Sawada, G. Signorelli, G. Terracciano G. Signorelli, G. Terracciano TC: G. SiragusaTC: G. Siragusa Event Generator for VMC: F. Cei, A. MazzacaneEvent Generator for VMC: F. Cei, A. Mazzacane Database: D. Barbareschi, R. SawadaDatabase: D. Barbareschi, R. Sawada Blue: young people who recently joined the collaboration

17. 19 July 2005Fabrizio Cei17 MegRoot Architecture MegRoot FrameworkMegRoot Framework –Based on ROOT –User code in C++ –Usage of FORTRAN libraries Geant3, event generators, “microcernlib”Geant3, event generators, “microcernlib” Integrates reconstruction and analysis softwareIntegrates reconstruction and analysis software Each detector subsystem has one single packageEach detector subsystem has one single package (one directory, one library) (one directory, one library) Calibration constants read via MySQL interfaceCalibration constants read via MySQL interface

18. 19 July 2005Fabrizio Cei18 MegRoot status The structure of all Classes is complete up to the Digitization stepThe structure of all Classes is complete up to the Digitization step (main purpose is to test the Reconstruction Modules) (main purpose is to test the Reconstruction Modules) All Methods have been designed and most algorithms haveAll Methods have been designed and most algorithms have been implemented been implemented The Reconstruction Class is currently being designedThe Reconstruction Class is currently being designed Reconstruction Class will read out ROOT ObjectsReconstruction Class will read out ROOT Objects (MC Digits) or streamer objects (raw data) (MC Digits) or streamer objects (raw data) Intense collaboration between Detector Experts andIntense collaboration between Detector Experts and Core Offline Group under way Core Offline Group under way Sofware Workshop in Lecce (21 - 22 June) very successfulSofware Workshop in Lecce (21 - 22 June) very successful (several proposals and new ideas) (several proposals and new ideas) Lecce people are joining the effort to bring the LP code withinLecce people are joining the effort to bring the LP code within MegRoot and analyze the data with the rest of the collaboration MegRoot and analyze the data with the rest of the collaboration

19. 19 July 2005Fabrizio Cei19 What’s missing in MegRoot Waveform decodingWaveform decoding Detailed structure of the Reconstruction classDetailed structure of the Reconstruction class MySQL interface needs to be extended to the final Detector (presently it only works for LP)MySQL interface needs to be extended to the final Detector (presently it only works for LP) Calibration ModuleCalibration Module Farm Manager Code (Global/Local)Farm Manager Code (Global/Local) Not final geometry (to be borrowed from GEM)Not final geometry (to be borrowed from GEM) It could be one of the most CPU consuming processes

20. 19 July 2005Fabrizio Cei20 Offline Milestones LP in MegRoot: ongoing, analysis within OctoberLP in MegRoot: ongoing, analysis within October CVS: September 2005CVS: September 2005 Reconstruction Class: October 2005Reconstruction Class: October 2005 Estimate LXe shower analysis CPU load: October 2005Estimate LXe shower analysis CPU load: October 2005 Estimate WF feature extraction CPU load: December 2005Estimate WF feature extraction CPU load: December 2005 Calibration Module: it will start in November 2005 (after completion of Reconstruction Class)Calibration Module: it will start in November 2005 (after completion of Reconstruction Class)

21. 19 July 2005Fabrizio Cei21 Rough estimates of CPU/data storage needs “0 th order” approximation“0 th order” approximation - MC production GEANT3 simulation GEANT3 simulation Hit production & digitizationHit production & digitization - Data/MC reconstruction (partial) Computations based on Pentium III, 1.4 GHzComputations based on Pentium III, 1.4 GHz (faster computers available) (faster computers available) Data reconstructionData reconstruction – LXe: LP beam test data; QSUM, Linear Fit and MINUIT fit – DCH: Kalman Filter to 5 simulated charged tracks & Track extrapolation to TC (1.2 x storage and 1.5 x CPU) Track extrapolation to TC (1.2 x storage and 1.5 x CPU) - TC: Not implemented - TC: Not implemented Waveform decoding not implementedWaveform decoding not implemented

22. 19 July 2005Fabrizio Cei22 CPU estimates (msec/evt) 1) Hits + Digits productionReconstruction Montecarlo events generation 2000 – 6000 DCH reconstruction 200 (MC) LXe reconstruction 40 – 80 (LP data) TC reconstruction not included not included Total 2000 – 6000 250 – 300

23. 19 July 2005Fabrizio Cei23 CPU estimates 2) Assumptions:Assumptions: –Trigger rate: 20 Hz (physical events) - MC: - 10 12 accidental events obtained by “Event Cocktail” (10 6 Michel positrons & 10 6 AIF/RD photons)/year; (10 6 Michel positrons & 10 6 AIF/RD photons)/year; Reconstruct ~ 10 8 events & use others for occupancy checks; Reconstruct ~ 10 8 events & use others for occupancy checks; - 2 x 10 7 correlated events in the signal region/year. Results:Results: - Montecarlo production & event cocktail: 10  30 CPU - Montecarlo production & event cocktail: 10  30 CPU - MC/Raw data Reconstruction : > 20 CPU/proc. - MC/Raw data Reconstruction : > 20 CPU/proc. - WF decoding not implemented; - WF decoding not implemented; - Calibrations to be estimated; - Calibrations to be estimated; - No pre-filtering (it could reduce CPU time). - No pre-filtering (it could reduce CPU time).

24. 19 July 2005Fabrizio Cei24 Data Storage Estimate 1) REAL DATA  Assume 0.5 x 10 7 sec/year & an overall trigger rate of 100 Hz, 20 Hz of physical data and 80 Hz of calibrations ; 100 Hz, 20 Hz of physical data and 80 Hz of calibrations ;  Waveform data (channel occupancy assumed: 50 % for Lxe, 10 % for DCH & TC): 1.2 Mb/event  120 Mb/sec; Lxe, 10 % for DCH & TC): 1.2 Mb/event  120 Mb/sec;  Compression factors: 10 for true events (obtained in PIBETA); 10 for true events (obtained in PIBETA); 100 for calibrations  0.12 Mb/event for physical 100 for calibrations  0.12 Mb/event for physical events, 0.012 Mb/event for calibrations events, 0.012 Mb/event for calibrations  Data storage: (20 x 0.12 + 80 x 0.012) Mb/sec = 3.4 Mb/sec  3.4 Mb/sec x 0.5 x 10 7 sec/year = 17 Tbyte/year

25. 19 July 2005Fabrizio Cei25 Data Storage Estimate 2) MONTE CARLO  Assume a total production of 10 12 accidental events (dominant background in the signal window) and 2 x 10 7 correlated background in the signal window) and 2 x 10 7 correlated events/year; first sample obtained by merging two 10 6 events/year; first sample obtained by merging two 10 6 independent samples of positrons & photons; to reduce problems independent samples of positrons & photons; to reduce problems of multiple disk accesses, MC events must be duplicated of multiple disk accesses, MC events must be duplicated (x 2 correlated, x 20 accidental). (x 2 correlated, x 20 accidental).  Event size based on storing photon arrival times on LXe: 200 kb/event; waveforms not simulated and noise not included. 200 kb/event; waveforms not simulated and noise not included.  Data storage: - (200 kb/event x 2 x 10 7 x 2) = 8 Tb/year (correlated events); - (200 kb/event x 2 x 10 7 x 2) = 8 Tb/year (correlated events); - (200 kb/event x 2 x 10 6 x 20) = 8 Tb/year (uncorrelated - (200 kb/event x 2 x 10 6 x 20) = 8 Tb/year (uncorrelated events); + factor 2 overhead for storing information of events); + factor 2 overhead for storing information of most significant events: TOTAL ~ 30 Tb/year most significant events: TOTAL ~ 30 Tb/year

26. 19 July 2005Fabrizio Cei26 Data Storage Estimate 3) Summary Real data: 17 Tbytes/year Monte Carlo: 30 Tbytes/year Overhead (DSTs, reconstructed info …) ~ 15 Tbytes/year __________________________________________ Total ~ 60 Tbytes/year

27. 19 July 2005Fabrizio Cei27 Conclusions  Relevant progresses were obtained in MC and offline framework;  About 10 young people joined the collaboration in the offline core group; the MC group is also in expansion; offline core group; the MC group is also in expansion;  A first version of Offline framework was released; important milestones were defined for the Offline group; important milestones were defined for the Offline group;  Other software jobs are under way: tracking and pattern recognition algorithms, studies of possible calibration procedures … recognition algorithms, studies of possible calibration procedures …  Thanks to the experience gained in the beam test and to the good level of sophistication reached by the MC code we are good level of sophistication reached by the MC code we are in a position to perform a first (“0 th order”) estimate of in a position to perform a first (“0 th order”) estimate of CPU power and disk storage needs of our experiment. CPU power and disk storage needs of our experiment.  We are starting to think at physics analysis (likelihood, blind …)

28. 19 July 2005Fabrizio Cei28 Backup slides

29. 19 July 2005Fabrizio Cei29 MegRoot structure MegRoot run management interface classes detector base classes data structure base classes Detectors DCHLXE FMDTC STEER PYTHIA6 Geant3 MICROCERN Geant4 ROOT HIJING…EVGEN Geant3 VMC Geant4 VMC External packages VMC

30. 19 July 2005Fabrizio Cei30 Remarks One big contribution missing: WF feature extractionOne big contribution missing: WF feature extraction Montecarlo has space for improvementMontecarlo has space for improvement Offline needs to implement more realistic algorithms for LXe reconstructionOffline needs to implement more realistic algorithms for LXe reconstruction Fast data transmission protocol needed because many nodes will access few disks.Fast data transmission protocol needed because many nodes will access few disks.

31. 19 July 2005Fabrizio Cei31 Dataflow Online Disk Server 3.4 MB/sec Offline Disk Server 0.35 MB/sec DAQ Hits-Digits producion 3.75 MB/sec 0.35 MB/sec Reconstruction Farm Reconstruction Farm MC Data