ECAL perfomance: lessons learned and future plans

1. ECAL perfomance:lessons learned and future plans P. Meridiani & C. Seez Physics Days 17/01/2007 Paolo Meridiani - INFN Roma1

2. Lessons/achievements of PTDR [1] • Test beam 2004 results show that ECAL “intrinsic performance” is as expected Paolo Meridiani - INFN Roma1

3. Lessons/achievements of PTDR [2] • Important lesson from 2004 TB: • Amplitude reconstruction from digitized time samples • Only a single set of weights required for all channels • Only asynchronous (test beam) running requires finely tuned weights • Event by event pedestal subtraction, using “presamples” is important and useful • Using more than one weight on the signal gives only very small (5%) reduction of energy equivalent noise Paolo Meridiani - INFN Roma1

4. Lessons/achievements of PTDR [3] • Performance in CMS dominated by: • Tracker material • Calibration issues • The big issue for ECAL is calibration • 27/52 pages in ECAL chapter were on this topic • Understanding of the tracker material effects is one the biggest challenge for the in-situ calibration • Includes also the correction for radiation induced transparency changes using the laser system Paolo Meridiani - INFN Roma1

5. Since PTDR • 2006: “integration” of the various components which will be used for the final CMS setup • DAQ • Offline software • DQM • Many objectives have been achieved: • Transition to CMSSW of the ECAL Local Reconstruction code & simulation • CMSSW DQM version • Cosmic intercalibration campagn • Test Beam campaign • Ecal test beam in H4 • ECAL + HCAL test beam in H2 • MTCC Paolo Meridiani - INFN Roma1

6. Local Reconstruction code • Simplification of the data tiers profiting from the EVD restructuring • Implementation used methods demonstrated in the 2004 test beam • Local reconstruction integrated with the condition DB • Whole procedure (reconstruction code + condition evaluations) fully validated using the test beam data • At the moment the code is rather stable and no big changes are foreseen for the future Paolo Meridiani - INFN Roma1

7. Simulation • Hits • No big development w.r.t. to OSCAR. Mostly a porting of the existing code • Major ECAL development was the support of the test beam setups, previously not included in OSCAR. More work is needed to include also the beam line components • Current work mostly concentrated in the comparisons between Geant 4.8/4.7 versions together with comparison with the test beam data • Digitization • Completely rewritten w.r.t. to ORCA • Moved to MGPA electronics • Simplified the code in many areas to make it more mantainable • Work is still needed in the trigger primitives emulation • EE electronics mapping is still lacking. Some action is needed here Paolo Meridiani - INFN Roma1

8. DQM [1] • In the 2006 the ECAL DQM moved from the standalone version used in the cosmic setup to the CMSSW DQM architecture • It has been used in all the 2006 tests (H4,H2, cosmic, MTCC, DAQ integration center) • Proved to be in good shape for detector specific monitoring, under real-life stress-test conditions • Heavily used for debugging purposes in the test beams • Simple access to all high-level products used in analysis, thanks to the re-use of standard CMS framework/code • Costantly under development and continuous update/ upgrade/ improvements • Ready to be moved to the final CMS setup version Paolo Meridiani - INFN Roma1

9. DQM [2] ECAL DQM - web static pages Paolo Meridiani - INFN Roma1

10. Cosmic Intercalibration • Every integrated SM is/will be tested for around one week using a specific cosmic setup • 10° inclined SM • APD HV raised to have gain 200 • About 5 million triggers are collected for each SM • So far 22 SMs have exposed to cosmic rays • Useful for two main reasons • Initial commissioning of the integrated SM • Preliminary intercalibration coefficient can be computed at a precision of around 2% for all channels • Systematics w.r.t to beam intercalibration are under detail study Paolo Meridiani - INFN Roma1

11. TB06 campaign [1] • Two setups, both have been a great success • H4 • ECAL only, 10 SMs have been tested. 1 SM has been tested twice • H2 • ECAL + HCAL, lots of data with different beams (e, p+ ,p- on target) and E (1300GeV) • First real integration tests DAQ + DQM + Offline CMSSW software • H2 ECAL + HCAL DAQ have worked together Paolo Meridiani - INFN Roma1

12. TB06 campaign [2] • Analysis is still going on for both TB data • Different intercalibration techniques have been tested on the real data both in H4 & H2 • Reproducibility below 0.3% • The 10 beam intercalibrated SMs will play an important role at the beginning of the LHC operations in order to understand calibration systematics of the in-situ method • Full validation/tuning of the simulation is going on. This will be the starting point for the CMS simulation • H2 is fundamental to make the ECAL+HCAL system to be used as a single combined calorimeter Paolo Meridiani - INFN Roma1

13. Clustering workshop (November 2006) • Excellent performance and extensive understanding of details of cluster and supercluster reconstruction in PTDR • Time now for simplification, unification, systematization of knowledge/algorithms/code • This stage was begun in “Clustering Workshop” in October 2006 • Need for agreed definition of Calibrated RecHits • And Monte Carlo data should correspond to ‘calibrated real data’ if the definition differs • Clear and clean separation of “Calibration” and “Corrections” • Appropriate clustering for all energies • Follows natural and logical progression: • Obtain best performance using any means to hand • Building up understanding of the details and issues • Go back and simplify, consolidate, unify, without sacrificing the performance Paolo Meridiani - INFN Roma1

14. PiZero Calibration • Important progress on π0 intercalibration • Work done with OSCAR/ORCA system: approval will be sought for AN soon • Internal notes from Rome, CalTech, UCSD and Minnesota are being amalgamated • Demonstration of the ability to select pi zero events online and create a special stream for calibration is still lacking First resonance seen in CMS :-D H2 Data Paolo Meridiani - INFN Roma1

15. Ecal Geometry • Old xml “hardcoded” Ecal Geometry needs to be changed • Not updated for non-crystal support, cooling, readout • Not mantainable • Not usable for alignment purposes • Primary d.o.f. is the supermodule alignment • First implementation is delivered for the barrel (B. Heltsey) • Also effort on endcap and preshower is towards completion Paolo Meridiani - INFN Roma1

16. What should be done this year • We have a solid base to start from but refinement/completion work is needed in many areas • Primary goal: deliver a full coherent picture for calibration/corrections • Integration/use of the different calibration methods • Integration with the laser monitoring • Estimation of corrections using the data • Make it robust against real data problems (dead-channels...) • Detailed definition of the workflow from raw data to calibrations propagated to the condition DB • Other important tasks • Procedure to measure the tracker material budget. Whose job? Does it need a joint task force ECAL + Tracker? Paolo Meridiani - INFN Roma1

17. Immediate Tasks • Deliver a complete task list and identify where there is lack of manpower • Complete the parameterized geometry • Put in the EE electronics mapping • Define/choose a selective readout algorithm for low luminosities • Speed optimized Raw to Digi unpacking • and Digi to Raw code • Implement a standard dead channel ‘energy estimate’ for RecHits • Complete the development of the infrastructure needed for the laser corrections • MC truth tools Paolo Meridiani - INFN Roma1