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Reconstruction and Analysis Tools for LC physics. Tony Johnson SLAC Victoria Linear Collider Workshop July 2004. Contents. Existing Code Review capabilities of existing hep.lcd package LCIO Overview and Status LCIO Reconstruction Output LCIO Analysis package for Java/JAS3
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Reconstruction and Analysis Tools for LC physics Tony Johnson SLAC Victoria Linear Collider Workshop July 2004
Contents • Existing Code • Review capabilities of existing hep.lcd package • LCIO Overview and Status • LCIO Reconstruction Output • LCIO Analysis package for Java/JAS3 • WIRED Event Display • Recent developments (work-in-progress) • Port of entire reconstruction/analysis framework to LCIO/Java 1.4(5)/JAS3 • Issues • Timescale • Future Plans • International Reconstruction/Analysis Framework
hep.lcd Overview • Java based analysis reconstruction and analysis package • Runs standalone or inside JAS • Full Reconstruction (tracking+calorimetry) • Analysis Tools (including WIRED event display) • Fast MC • Smeared tracks and calorimetry clusters • Physics Tools (Vertex Finding, Jet Finding) • Beam Background Overlays • Contributed Area • Analysis Utilities and sample analyses provided by users
hep.lcd Physics Utilities • Physics Utilities • 4-vector, 3-vector classes • Event shape/Thrust finder • Jet Finders • Many kT algorithms implemented (e.g. Jade and Durham ) • Extensible to allow implementation of other algorithms • Event Display • Topological Vertexing • Implementation of SLD’s ZVTOP • Event Generators • Can be run directly in FastMC • Can be run standalone, e.g. for writing stdhep files • Diagnostic Generator • User-defined particle mix, momenta and vertices. • Generator framework extensible for other generators • PYTHIA, HERWIG, ISAJET, …
Full Reconstruction • Reconstruction of fully simulated MC data. • Designed to allow easy implementation of different algorithms. • Reconstructs “low-level” objects: tracks and calorimeter clusters. • Further reconstruction (jets, flavor-tagging,…) deferred to analysis stage.
Full Reconstruction • Tracking • Hit Smearing/Efficiency (detector simulation puts out “perfect” hits) • Random Background overlay • Track Finding: • Full pattern recognition in the Central Barrel region • Tuned for Large and Silicon Detectors • Track Fitters: • SLD Weight Matrix Fitter • Can do Single Detector or Combined fit (e.g. VTX+TPC) • Calorimetry • Cluster Finding • Several Clustering Algorithms Currently Implemented • Cluster QA package developed • Cluster Refinements • Combine HAD + EM clusters • Endcap + Barrel overlap region • Identify cluster as originating from charged/neutral hadron, EM
Beam Background Overlays • Take output from full beam simulation (from IR/backgrounds group) • Feed into full detector simulation • Build library of simulated background bunches • Overlay backgrounds on signal events at start of reconstruction • Adjust timing of hits (for TPC e.g.) • Add energy in calorimeter cells • Allows to change #bunches/train, bunch timing
Recent improvements to hep.lcd • Ported to work with JAS3 • Old packages running in JAS3/AIDA framework • No major changes to reconstruction framework • New digitization routines being added (N.Sinev) • Cluster identification code (G. Bower) • Cluster diagnostic package (R. Cassell) • Improved Stepper (C. Milstene) • Forward Tracking (N. Graf) • Flavour Tagging (D. Jackson) • Particle ID (B. Wilson, S. Rolnick) • Support for Non-Projective geometries (G. Lima)
hep.lcd analysis tools • Tutorial: http://jas.freehep.org/jas3/Tutorial/index.html
hep.lcd package pros-and-cons • Features: • Can run standalone or inside JAS • Runs on almost any platform • No dependencies on pre-installed software or network connections. Can install and run in <15 minutes from Snowmass 2001 CD • Problems: • Few changes/improvements since Snowmass 2001 • IO based on old LCD SIO format • No way to write output from reconstruction
Introduction to LCIO International Standard for linear collider data storage
LCIO Persistency Framework Generator Analysis Recon- struction Simulation Motivation for LCIO Java, C++, Fortran Java, C++, Fortran Geant3, Geant4 Java, C++, Fortran geometry
LCIO Status • LCIO 1.0 release (simulation/rawdata) stable since November 2003 • LCIO 1.1 (“beta” reconstruction) may 2004 • LCIO 1.2 (stable reconstruction) august 2004 • “micro” workshop at SLAC mid-august to finalize design
LCIO plugin for JAS3 • Works with any LCIO file • Diagnostic tools allow to step through and view events
Wizard will create outline of analysis, and can include sample analysis code. Main routine allows running outside of JAS LCIO plugin for JAS3 • Event Analysis
Using WIRED with LCIOPlugin • LCIO files do contain positions of all hits, but no detector geometry info except “detector name” • LCIOPlugin+WIRED can view hits for any file, but these are hard to visualize without detector • LCIOPlugin can read external HepRep2 file describing detector geometry • Location currently needs to be specified by hand • HepRep file (xml) can be generated: • by hand (quite easy for simple geometry) • by Geant4 using HepRep2 writer (perhaps with some filtering to remove excess details) • By program using Java or C++ HepRep API • Easy to add analysis specific code to create visualizations for special items (jets, vertices etc.)
Tree controls visibility. (HepRep2 support in WIRED3 is preliminary) Picking supports viewing physics attributes WIRED3 with LCIO Plugin
LCIO Plugins pros-and-cons • Features: • Not dependent on any detector specific assumptions • Simple environment for debugging problems with LCIO and writing simple analysis routines • Detector independent event display • Problems: • No connection to hep.lcd reconstruction or analysis tools • Detector geometry must be specified by hand • Existing LCIO API does not emphasize user-friendliness • Detector geometry must be specified by hand
org.lcsim Goals • Retain core functionality from hep.lcd package • Full suite of reconstruction and analysis tools available to all LCIO users • Update to use LCIO for IO and as basis for simulation, raw data and reconstruction event formats. • Update/simplify framework using experience from hep.lcd • Internationalization • Try to make package independent of detector, geometry assumptions so can work with any detector • Read properties of detectors at runtime • Update to Java 1.4 (or 1.5) • Many improvements since hep.lcd framework was created. • Ability to run standalone or in JAS3 • Revitalize work on reconstruction algorithms
org.lcsim Status • Physics Utilities - done • stdhep reader • 3, 4-vector utilities • diagnostic generator • Jet finder, event shape utilities • Org.lcsim package – Phase I • Conditions framework – done • Ability to read detector constants from “zip” file • To define new detector just create new zip file and place on web • File is read and cached locally • Driver framework – done • Fast MC – done • IO Framework – working, needs final LCIO 1.2 • Event Display interface – in progress
org.lcsim Status • org.lcsim – Phase 2 - Reconstruction • Help needed! • Geometry - J. McCormick, W. Langeveld • Tracking – M. Ronan, E. von Toerne (et al) • Calorimetry – R. Cassell, … • Particle ID – B. Wilson, S. Rolnick • Digitization – N. Sinev, … • Vertex Finding - ?
Future • Distributed catalog for finding LCIO files • Work towards International Reconstruction-Analysis Framework • Taking best features of existing tools • Support for mixed-language (Java, C++, Fortran) modules • Perhaps Java “backplane” driving modules in any language, using LCIO as transient event store, and with common geometry/constants access??
Conclusions • hep.lcd package is old but still works and is being used for current analysis • LCIO 1.2 format very nearly complete • New org.lcsim package in development • Base package will be released soon after LCIO 1.2 • Then need to start work on porting/developing reconstruction code • More volunteers needed • Goal: Generate sample of fully simulated+reconstructed events for SiD, Large detectors by end of 2004
Links • LCIO: http://lcio.desy.de • hep.lcd: http://www-sldnt.slac.stanford.edu/jas/Documentation/lcd/ • Tutorials: • http://jas.freehep.org/jas3/Tutorial/index.html • http://www-sldnt.slac.stanford.edu/snowmass/Welcome.html • JAS3: http://jas.freehep.org/jas3 • WIRED: http://wired.freehep.org/ • HepRep: http://heprep.freehep.org/ • Discussion Forums: • http://forum.linearcollider.org