Data Products and Processing Tutorial
Revision as of 15:44, 13 June 2019 by Brownd (talk | contribs) (→Glossary of Principle Reconstruction Modules)
Tutorial Session Goal
This tutorial will explore the data products used in Mu2e and the modules and algorithms which create them. It is part of the June 2019 Computing and Software tutorial
Session Prerequisites and Advance Preparation
This tutorial assumes knowledge of art and the Mu2e detector. You will need to understand basic principles of how modules and event processing function in art. You will need to understand C++ data structures and fundamental types. You should have completed the following tutorials:
- Mu2e detector overview
- Mu2e_Offline_Tutorial
- Running_Art_Tutorial
Session Introduction
The information content of Mu2e is stored in the form of art data products. There are several levels of information:
- Monte Carlo generator information
- Geant4 information
- Digitized detector data, or digis (Offline format)
- Reconstructed data
We will explore a few of these, and the algorithms which create them.
Exercises
General
- Search for content (data products) in RecoDataProducts, MCDataProducts, etc
- Search for algorithms (modules) that (say) build tracks, find clusters, identify background ,...
- examine classes_def.html
Monte Carlo Generators
- Mu2e generators and GenParticle class
Geant4 and Detector Simulation
- The G4 Mu2e Detector description text files
- Examine the SimParticle and StepPointMC classes
- Virtual detectors
Digitized signals
- Digi specification
The term 'digi' refers to the digitized detector data stored during Mu2e operations by the Data Acquisition (DAQ) system.
- Download and open doc doc 4914
- Digitization simulation (tracker, CRV, ...)
Reconstruction
- Track reconstruction algorithms and data products
- Hit Reconstruction
- Time Clusters
- Helices
- Kalman Fit
- Calorimeter reconstruction algorithms and data products
- CRV reconstruction algorithms and data products
Reference Materials
Glossary of Data Products
| class | description | contents |
|---|---|---|
| StrawDigi | Offline format of a single Tracker hit | TDC and TOT from both straw ends, ADC waveform |
| ComboHit | Calibrated Tracker hit, or an aggregate of several hits | position in space, time, and time differences |
| TimeCluster | Collection of ComboHits nearby in time and (roughly) space | average time and error |
| HelixSeed | Helix interpretation of a subset of hits in a TimeCluster | Helix parameters, t0, ComboHits with position along the helix |
| KalRep | Full Kalman filter fit result: not persistable | Complete set of weight and parameter matrices and vectors used in the fit |
| KalSeed | Compact summary of the Kalman filter fit result | Sampled fit segments, associated straw hits and straws |
| KalSegment | KalSeed component: local fit result | Fit parameters and covariance at a particular point |
| TrkStrawHitSeed | KalSeed component: straw hit as used in fit | hit position, residual, time, drift radius, errors, ... |
| TrkStraw | KalSeed component: straw intersected by the fit | strawID, DOCA to wire, radiation length, energy loss, ... |
| CaloCluster | Cluster of calorimeter crystal energy deposits | Total energy, center of gravity (COG), energy moments |
| CrvCoincidenceCluster | Cluster of adjacent CRV reco pulses | position, PE count, start and end times |
Glossary of Principle Reconstruction Modules
| module | category | description |
|---|---|---|
| StrawDigisFromStepPointMCs | Simulation | Converts G4 straw energy deposits into StrawDigs |
| StrawHitReco | Reconstruction | Converts StrawDigs into single-straw ComboHits |
| CombineStrawHits | Reconstruction | Combines adjacent ComboHits in a panel into aggregate ComboHits |
| FlagBkgHits | Reconstruction | Identify (flag) panel ComboHits likely produced by low-energy Compton or delta-ray electrons |
| TimeClusterFinder | Reconstruction | Group time-adjacent panel ComboHits (and calorimeter cluster if available) into a cluster |
| RobustHelixFinder | Reconstruction | Fit a cluster of panel ComboHits to a simple helix using space-point positions |
| CalTimePeakFinder | Reconstruction | Group panel ComboHits near a calorimeter cluster in time into a cluster |
| CalHelixFinder | Reconstruction | Fit the calorimeter cluster position, target position and panel ComboHits to a simple helix |
| KalSeedFit | Reconstruction | Fit single-straw transverse wire positions to a helix, using a simple helix as starting point |
| KalFinalFit | Reconstruction | Kalman filter fit of single-straw drift ellipses, constrained with calorimeter cluster time (if present) |