CMSSW Tutorial A. Nikitenko IntroductionIntroduction Example of reconstruction: “how to”Example of reconstruction: “how to” Running CMSSW with ASAPRunning CMSSW with ASAP Home work useful for tau id groupHome work useful for tau id group

Introduction

Event processing: “physics” view Event generation (in MC world)Event generation (in MC world) DigitizationDigitization Local reconstructionLocal reconstruction High level object reconstructionHigh level object reconstruction Event selectionEvent selection Event analysisEvent analysis

Event processing: CMSSW view Event processing is a sequence of modulesEvent processing is a sequence of modules Type of CMSSW modules:Type of CMSSW modules: –Source Event generator: PYTHIA, HERWIG, …Event generator: PYTHIA, HERWIG, … File containing some data for further processingFile containing some data for further processing –MC info –Digi –….. –EDProducer –EDFilter –OutputModule –EDAnalyzer

Event processing: CMSSW view Important to know one of the CMSSW rules: object produced in one module can not be updated/modified in other module

How to run it CommandCommand cmsRun –p name.cfg cmsRun –p name.cfg run event processing run event processing User fileUser file name.cfg name.cfg define modules that user want to run and sequence of running (path) define modules that user want to run and sequence of running (path).cfg file is configuration file which uses CMS program configuration language.cfg file is configuration file which uses CMS program configuration language

Example: gen + sim-digi-reco in one step + analysis Full example can be found onFull example can be found on I will show you now only few elementsI will show you now only few elements –Jet reconstruction –Analysis (access to information) with “Framework analyser”. Code fragments shown on the next slides are taken from allReco.cfg

Source module (or POOL Source) I have generated already some events (di-taus, back-to-back) and store them into mcpool.root file. This file is “source module” for further event processingI have generated already some events (di-taus, back-to-back) and store them into mcpool.root file. This file is “source module” for further event processing Standard name

Module creating “raw” Calo Towers Module name; user defines it. Name of c++ class in CMSSW who produces Calo towers Code above could be put into.cfi file and this file can be included in.cfg as:

module caloTowers = CaloTowerCandidateCreator { string src = towerMaker” double minimumEt = 0.5 double minimumE = 0.8 } Module creating Calo Towers used for jet finder Module name; user defines it. Name of c++ class in CMSSW who produces Calo Towers used by jet finder Name of the module who produced “raw” Calo Towers; see previous slide

Module creating jets Module name; user defines it. Name of c++ class in CMSSW who produces Calo Towers used by jet finder Name of the module who produced Calo Towers to be used by jet finder; see previous slide

Output Module Standard name User name to be used later User name of output filenames of modules produced objects user does not want to be stored into output file

Event processing steps: path Few modules can be combined as sequenceFew modules can be combined as sequence Modules and sequences define path: sequence of processing stepsModules and sequences define path: sequence of processing steps output module name

Analysis of output root file bare root - no CMSSW libs neededbare root - no CMSSW libs needed FWlite mode - few CMSSW libs neededFWlite mode - few CMSSW libs needed Analysis in a Framework analyzerAnalysis in a Framework analyzer –cmsRun –p name.cfg name.cfg is user configuration file to run analysisname.cfg is user configuration file to run analysis analysis uses full CMSSW frameworkanalysis uses full CMSSW framework See on the next slides example of full Framework analysis

analysis.cfg user name Name of c++ class performing analysis’ user access info and fill/store histos there modules which produced objects in previous step to be analyzed now Output file from previous step

Access event data in Analyzer (Analyzer.cc)

Running CMSSW with GRID/ASAP Instructions can be found onInstructions can be found on Many thanks to ASAP teamMany thanks to ASAP team –Julia Andreeva –Olga Kodolova –Craig Munro –Juha Herrala

Homework useful for tau id group Compare two ways to suppress electron contamination to tau-jet :Compare two ways to suppress electron contamination to tau-jet : –cut on hottest HCAL tower E T in jet –cut on E T jet (hadr)/p T ltr Using instructionsUsing instructions (see page 7) (see page 7) analyze single e analyze single e and tau-jet of and tau-jet of p T = GeV, p T = GeV,  < 2.2  < 2.2.