DZero Monte Carlo

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DZero Monte Carlo

• Status, Performance,
• and Future Plans

Greg Graham U. Maryland - Dzero 10/16/2000
ACAT 2000
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DZero Monte Carlo Components

• GEANT-3 based hits simulation (D0gstar)
• Separate executable for digitization and pileup
  (D0Sim)
• Parameterized Monte Carlo Simulation (PMCS)
• Infrastructure for MC generation (MCC)
• Trigger Simulator/Emulator (Trigsim)
• D0 Reconstruction Program (D0Reco)
• Wont talk about here ...

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Aside on DZero Code

• Dzero executables consist of packages running in
  a framework
• Packages inherit hook methods
• Framework calls hook methods of packages in well
  defined order
• Dynamic Requirements Based
• Static User defined order given at runtime
• Runtime parameters handled by RCP database system
  (M. Paterno)
• RCP script files tied to code releases in CVS
• Events are tagged with RCP IDs

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Aside on DZero Object Model (D0OM)

• Persistency mechanism D0OM
• loosely based on ODMG standards
• Supports CERN DSPACK as well as EVPACK I/O
  packages
• EVPACK can attain factor of 2 compression over
  DSPACK

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Generators

• Pythia v6.129
• Upgrade soon to at least 6.134
• Isajet v7.44
• Herwig v6.1
• Special Purpose
• Single Particle
• Cosmic Ray
• etc.

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GEANT-3 Based Monte Carlo (D0gstar)

• GEANT 3.21
• C wrappers around Fortran code
• Almost complete model of the DZero detector
• FPD to be included when double precision GEANT-3
  is integrated
• Small detectors (i.e.- luminosity monitor) to be
  included soon

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Digitization Program (D0Sim)

• Includes packages to digitize hits in all
  detector systems in D0Gstar
• pileup package
• Simulates pileup in all detector systems
• Poisson or Constant sampling of Min Bias events
• Simulates effects of noise in calorimeter and the
  baseline subtracting electronics

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Performance D0gstar/D0Sim

• Event Size (Pythia ttbar events)
• D0gstar 0.9 MB/ev
• D0Sim 1.0 MB/ev
• Event Time (200 MHz - Origin 2000)
• D0gstar 110 sec/evt (pmc03.00.01)
• D0Sim 80 sec/evt (psim01.01.00)
• These are still rough numbers while the issues of
  optimization and output are being resolved.

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Parameterized Monte Carlo (PMCS)

• Packages divided into three categories
• FAST Track High level physics objects
• Charged Particles, EM particles, Jets, Muons,
  Tau, Vertices
• Medium Track Quick simulation of some detectors
• Calorimeter, silicon
• Slow Track Detailed simulation of some
  detectors
• Calorimeter, silicon in more detail showers

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Parameterized Monte Carlo (PMCS)

• The fast track has the highest priority.
• Chunk output makes PMCS compatible with other D0
  tools
• Visualization, Analyze on Fast Track objects
• Some D0Reco packages with Medium, Slow
• Small packages facilitate the contribution of
  many towards PMCS
• Maryland, Rochester, IN2P3 Lyon, TIFR

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Parameterized Monte Carlo (PMCS)

• Package based
• flexible output choices
• D0 Chunks
• Ntuples HBOOK or ROOT
• ROOT Tree

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Parameterized Monte Carlo (PMCS)

• Performance (Pythia ttbar events, 200 MHz Origin
  2000 machine)
• 22 events/sec
• Can do simple things well for now but need muon
  package and vertices

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Dzero Monte Carlo Challenge

• Phase II
• Ended April 2000
• Generated over 1 million events
• Worldwide Effort
• Phase III
• In progress
• Over 600K events so far processed by D0GSTAR

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Running Dzero Offline Executables

• Help for managing the MCC ...
• mc_runjob A package written in Python
• Runs most D0 Offline Executables
• All of them in principle
• Chains executables together
• Handles naming of input and output files
• Handles seed generation, run numbers, etc.
• Macro Script driven gt Regular way to specify
  processing steps !

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• Mc_runjob
• Configurators
• Run and configure each D0 Offline executable
• The Linker
• Links Configurators
• Collects shell scripts that actually do the work
• Macro scripts
• The Linker and Configurators obey a regular set
  of macro commands in macro scripts

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• Inheritance Hierarchy
• Inheritance is used to incorporate D0 specific
  configuration (ie - RCP, runtime environment,
  naming, SAM metadata)
• Other special purpose configurators can handle
  the batch system, manage a list of files, etc.

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Graphical Support

• While primarily a macro script driven tool, the
  mc_runjob inheritance hierarchy also provides
  core tools with GUI methods that build a GUI
  from information contained in the configurators
  themselves.

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Automatic Processing Request Handling System

• In MCC-II Much of the work of generating events
  and keeping track was done by hand.
• In MCC-III it still is, however
• Automatic processing tools are nearing completion
• Tracking in Oracle DB
• Tools to generate events, specify processing
• Tools to store/transport output

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• Automatic Request Processing System

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Physics Process Specification

• Schema part of SAM system

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Automatic Request Processing Schema

• Schema part of SAM system

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Remote Processing Centers

• Monte Carlo simulation, digitization, and
  eventually some MC reconstruction will be handled
  offsite.
• Currently operating RPCs
• UT Arlington IN2P3, Lyon NIKHEF, Amsterdam
  Prague
• Future planned RPCs
• Lancaster Rio de Janeiro TIFR
• Generated events will be stored with SAM
• We expect better than 100K events/day

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Trigsim

• A trigger emulator/simulator
• Code run in trigsim will be the same code that
  runs in the actual trigger processors where
  applicable including the L1 firmware
• Many packages
• 1 package for each L1/L2 trigger subsystem
• Dynamic framework
• The processing order depends upon the input
  requirements of each package - the framework
  sorts it out

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Trigsim Status

• Production release Deadline Nov 1, 2000
• Currently in development releases
• L1/L2 cal, L1/L2 Muon, L1 FT, L2 STT
• Framework for running tsim

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Future Plans

• Complete all functionality of D0gstar, D0Sim
• Of course, this never really ends
• Optimize speed and size of output
• Complete functionality of PMCS
• No production release planned yet
• Make the trigsim production release deadline
• Test the automatic processing system on the D0
  Farm system and put into production
• Will happen this week (I hope)