Paolo Meridiani - INFN Roma1 1

ECAL perfomance:lessons learned and future

plans

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]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]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]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 PTDRSince 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 codeLocal 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

SimulationSimulation

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]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]DQM [2]

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Paolo Meridiani - INFN Roma1 10

Cosmic IntercalibrationCosmic 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]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, on target) and E (1300GeV)

First real integration tests DAQ + DQM + Offline CMSSW software

• H2 ECAL + HCAL DAQ have worked together

Paolo Meridiani - INFN Roma1 12

TB06 campaign [2]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)

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 CalibrationPiZero 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 GeometryEcal 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

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 TasksImmediate 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