Event Processing
Applications
summary
Gabriele Cosmo (CERN)
Co-convener: Avi Yagil (FNAL)
Chairs: Witold Pokorski, Alberto Ribon, Liz Sexton-Kennedy
Pedro Arce, John Apostolakis, Chris Jones
Event Processing Applications summaryComputing in High Energy Physics 2006 – Mumbai (India)
Outline


Contributions
Application Areas
• Simulation



In the experiments
Simulation tools
Simulation validation
• Frameworks & data models
• Reconstruction


Tracking algorithms
Alignment
• Visualization, commissioning

Impressions …
17 February 2006
Event Processing Applications summary
2
Contributions
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40 parallel talks
• Not all talks treated here …
• All slides are available on the web

25 posters
• Not treated in this talk
17 February 2006
Event Processing Applications summary
3
Presentations
4
Simulation

Geant4 simulation
• In production: CMS, ATLAS, LHCb
• ILC, BESIII, CBM
• Heavy ion therapy

Fluka
• The future main simulation engine in ALICE
(Geant4 as alternative)
• Source code available on request as of last July
2005 release

Need for fast-simulations
• CMS, ATLAS
17 February 2006
Event Processing Applications summary
5
#3 – A.Rimoldi, The ATLAS Detector Simulation – an LHC challenge
17 February 2006
Event Processing Applications summary
6
CMS simulation




Switched from GEANT3 to GEANT4
simulation end 2003
So far the CMS OSCAR simulation
package delivered ~100 M physics
events for CMS 2004 Data Challenge
and on-going Physics TDR studies
OSCAR being adiabatically replaced
by a new suite (SimG4), based on the
new Event Data Model Software
Framework
CPU: SimG4  1.5 x SimG3
 with lower production cuts!

Memory: ~110 MB/evt for pp in
SimG4
 vs. ~100 MB in SimG3

Robustness: from ~1/104 crashes in
pp events in DC04 to < 1/106
crashes in latest productions
#243 – D.Elvira, M.Stavrianakou, CMS Detector and Physics Simulation
7
ALICE
simulation


FLUKA VMC
implementation completed
Testing well advanced
• TGeo/FLUKA validation
completed
• Good agreement with G3
and Testbeam


FLUKA VMC will be used in
the next ALICE Physics
data challenge
Plan to use Geant4 as
alternative simulation
engine
#387 – A.Morsch, FLUKA and the
Virtual Monte Carlo
8
Simulation tools
#371 – J.Apostolakis, Geant4 in production: status and developments
2006 Recent developments
10
Event Processing
Applications
summary
#25717–February
G.Cosmo,
& upgrades
to the
Geant4 geometry modeler
Fluka
17 February 2006
11
Processing Applications summary
#420 – L.S.Pinsky, Update on theEvent
status
of the FLUKA Monte Carlo Transport code
Parameterised Simulation
17 February 2006
Event Processing Applications summary
#253 – J.Weng, GFLASH – parameterised
electromagnetic shower in CMS
12
CEDAR



CEDAR is primarily
a generator tuning
system, combining
JetWeb and
HepData
Aim is that any
expt MC
configuration
should be “CEDARblessed” to be
considered
trustworthy
Modular design
and many spin CEDAR also hopes to encourage code
offs
reuse and uptake of common interfaces
in HEP software
17 February 2006
Event Processing Applications summary
13
#253 – A.Buckley, HepData & JetWeb: HEP Data Archiving and Model Validation
Simulation validation
Simulation validation on the GRID
On candidate release 8.0 of Geant4
17 February 2006
Event Processing Applications summary
#300 – A.Ribon, Geant4 Acceptance
Suite for Key Observables
15
#308 – M.G.Pia, Simulation for LHC radiation background:
17 February 2006
Event Processing Applications summary
optimisation of monitoring and experimental
validation
16
Frameworks & data models
CMS Framework & data model


Ideas from Babar, CDF, CLEO, D0, and the
previous CMS system
Five types of dynamically loadable processing
components
•
•
•
•
Source (provides the Event to be processed)
Output Module (stores the data from the Event)
Producer (creates new data to be placed in the Event)
Filter (decides if processing should continue for an
Event)
• Analyzer (studies properties of the Event)


Components only communicate via the Event
Components are configured at the start of a job
17 February 2006
Event Processing Applications summary
#242 – C.Jones, The new CMS Event
Data Model and Framework
18
ATLAS Event
Data Model



17 February 2006
Event Processing Applications summary
Issues with
schema evolution
Solved adopting
an ‘Event
Management
Board’ and new
tools for
detecting schema
changes
Attempting ‘dual’
EDM design
19
#76 – E.Moyse, The ATLAS Event Data Model
ALICE Framework

Relatively small number of lines of code
•

Adopting strict code conventions
•



Pure CVS
Prototyping event processing with PROOF
Data challenge: last exercise before data
taking
•
•

No STL, templates or exceptions
Support for many compilers/platforms
No software management tool
•

Fully based on ROOT, including most of their
needed tools and specific software choices
Test of the system with simulation
Up to 3600 jobs running in parallel
Issues:
•
•
Difficulty in Planning in a widely distributed
community; difficulty in setting milestones
Communication seen as a real problem in spite of
frequent meetings
February 2006
Event Processing Applications summary
#39117
– F.Carminati,
The ALICE Offline
Framework
20
ILC framework

Requirements
• Easy to install, use, modify
and extend
• Must be modular and written
in C++
• Based on the international
ILC data format LCIO

MARLIN application
framework
• Set of classes providing the
core functionality
• Based on the concept of
processor
• A ‘processor task can be as
simple as creating one
histogram or complex as
track finding and fitting in
the central tracker
• AIDA interfaces for histo:
AIDAJNI/JAIDA, RAIDA (Root
based), …
17 February 2006
Event Processing Applications summary
#422 – F.Gaede, A modular Reconstruction Software Framework for the ILC
21
Reconstruction
RecPack


C++ reconstruction toolkit
Provides the common tools
of any reconstruction
program
•

avoids reinventing the wheel !!!
Modular structure allowing
for extensions in any
direction
• Can plug-in Geant4 for the
simulation step


Setup independent
Being successfully used by
several HEP experiments
17 February 2006
Processing Applications summary
#1 – A.Cervera
Villanueva, RecPack,Event
a general
reconstruction toolkit
23
CMS
Reconstruction

The code must be able to run
in three different scenarios:
1. Bare root: open the POOL
catalog, and inspect the Data
Objects (thus their centrality)
2. CMSSW-Lite: load a small
number of libraries, don’t
allow access to any
calibration, mag field map
etc
3. Full-CMSSW: full access to
calibrations and full
availability of libraries.

Old software (ORCA)
•
•
•
Used for the Physics TDR Vol
I, just published
Used by the vast majority of
users
Full functionality with the
new software before Summer
February 2006
Event Processing Applications summary
#27017
– T.Boccali,
CMS Reconstruction
Software
24
FatRas fast track
simulation



Fast track simulation for the
ATLAS Inner Detector
Spin-off of the new extrapolation
package (simulation using the
new reconstruction geometry)
Enhanced by the modularity of
the new ATLAS offline track
reconstruction, completely written
and embedded in the EDM

Usage in validation of track
finding and track/vertex fitting

Powerful tool for fast checks /
strategy finding
February 2006
Applications summary
#96 –17A.Salzburger,
The new ATLASEvent
FastProcessing
Track Simulation
engine
25
ALICE reconstruction
algorithms

Fast Hough-Transform TPC Tracking:
•
•
•
•

Very good efficiency (stable up to
dN/dy~8000)
Pt resolution worsens linearly with Pt
~5s comp. time for central PbPb event
with dN/dy~4000
~8 Mbytes/s processing rate (compressed
data)
~0.15 s/ADC count (hit)
FPGA implementation is under
development - would allow to diminish
the computing time to hundreds of
milliseconds
ITS Tracking:
•
•
•
Hough Transform tracks are efficiently
propagated to ITS
Fast and efficient ITS cluster finder,
vertex and tracking
Track parameters resolution is greatly
improved (excellent impact parameter
resolution)
February 2006
Event Processing Applications summary
#38517
– M.Ivanov,
Track reconstruction
algorithms for the ALICE High-Level Trigger
26
ATLAS track
reconstruction


A new framework
flexible and easy to
maintain
Novel tracking
technique in the MDT
• Multilayer Hough
Transform

Good performance
(and making use of
abstract interfaces)
17 February 2006
Event Processing Applications summary
#385 – D.Primor, Track reconstruction with the ATLAS detector
27
TPC distortions
corrections at STAR


Developed a technique
to determine and
apply TPC distortion
corrections on an
event-by-event basis
No obvious luminosity
limitations
17 February 2006
Event Processing Applications summary
#155 – G.Van Buren, Adaptive on-the-fly calibration of TPC distorsions
28
Tracking in High Density
Environment in ALICE

TRD detector is also very useful
for reconstruction
• was originally developed for
electron identification

Local Reconstruction
• Excellent space resolution for high
momentum track (small incident
angle)  significant improvement
in the momentum resolution
• Works in high density environment

The most significant improvement
is due to the correct error
parameterization
17 February 2006
Local Reconstruction
Event Processing Applications summary
#394 – M.Ivanov, Track reconstruction in high density environment
29
Event Selection with
Gene Expression Programming

New Evolutionary computation method
 Gene Expression Programming

Applied to Event Selection
Allows for

fast identification of powerful cuts

signal/background separation of 9295% accuracy for samples with S/N =
0.25, 1, 5

potential of discovering new
correlations between variables

large number of selection functions
does not improve the classification
accuracy


Still in the R&D phase
needs software development ->
underway
17 February 2006
Event Processing Applications summary
#135 – L.Teodorescu, HEP Event Selection with Gene Expression Programming
30
Alignment
Track based
alignment in CMS

HIP (Hits & Impact Points)
iterative method
• To be used for CMS pixel
alignment
• Basic idea: reconstruct
tracks normally, then
align individual detectors
or composite structures
• Modules or alignment
parameters can be free or
fixed
• Rigid support structures
can be aligned as well as
individual sensors
• Easily parallelizable
method
17 February 2006
Event Processing Applications summary
#356 – T.Lampen, Track based alignment of composite detector structures
Variable ATLAS
detector descriptions




Basic idea: have possibility of
building various ATLAS geometry
layouts with every single version
of ATLAS software
ATLAS geometry versioning
system is based on Hierarchical
Versioning of detector description
primary numbers stored in the
ATLAS Geometry Database
In order to switch between
different geometry layouts it is
enough to change a single
parameter: ATLAS top level
geometry tag
ATLAS geometry tags can be
passed across job boundaries
•
•
Using persistent TagInfo objects
Subsequent jobs can pick up
correct geometry configuration
from the input file bypassing
manual configuration through job
options
#67 – V.Tsulaia, Software Solutions for a
17 February 2006
Event Processing Applications summary
Variable ATLAS Detector Description
33
Silicon Tracker alignment
in ATLAS



Issue: Monitor the motion of ~ 6k Si modules using
tracks
Alignment software using global fit method
implemented
•
•
with global 2
Reasonable timing ~ 5ms/track
•
•
Extension to full geometry under study
More constraints to be considered, e.g. survey:
First tests showed it is quantitatively possible to align
a system with O(1000) DoF

•



To extend: more statistics and iterations to recover large
misalignments
Coming months: align many Silicon modules to high
precision - big impact on physics performance
Alternative alignment methods developed in ATLAS
•
Measurement error
Planned: study of constraints from resonances (Z or J/)
These are mainly iterative methods. No big system to
solve but iterations required even for small misalignments
New method under development (with Kalman filter)
Adding mult. scatt
17 February 2006
Event Processing Applications summary
34
#84 – A.Hicheur, Global fit method for the alignment of the Silicon Tracker in ATLAS Athena
COCOA



COCOA is a general purpose alignment
software developed as a Software
Engineering project
• User describes optical system in
ASCII files
• COCOA reconstructs the unknown
parameters and propagate the errors
COCOA stressed by years of use in CMS
Full CMS Link alignment system
(2865 parameters)
•
•

25 minutes in Athlon 1.3 GHz
Memory: 590 Mb (long double matrices)
Time and memory scales as (#param)2 !
•
•
Next challenge is to simulate full CMS (40k
params)
Methods under study
#321 – P.Arce, COCOA: General purpose software for simulation and
17 February 2006
Event Processing Applications summary
reconstruction of optical alignment systems
LHCb Alignment Framework

Misalignments are applied through detector
structure
•
•

Added runtime misalignments to detector
components
•

to allow both automatic runtime updating and propagation of changes, plus
versioning and time dependence of alignment parameters
The functionality was tested within the LHCb reconstruction chain
•

extending the LHCb detector description framework
Misalignments are tied in to the Conditions Database framework
•

“Interesting” detector elements have access to
misalignment matrix
Misalignment represents change from nominal alignment
in the reference frame of the detector element i.e.
relative to its parent detector element
LHCb subdetectors are using it to investigate detector alignment procedures and
strategies, systematic effects, etc.
The extension is a non-intrusive enhancement
•
respects the design principles of the LHCb detector description suite
#356 – J.Palacios, The LHCb Alignment framework
Access to Non-Event
Data for CMS

CMS has a unified data model for
all non-Event data
• Based on an ‘Interval of Validity’
accessed through an EventSetup
• Physicists have one set of rules to learn so as to access all such data

Design uses type-safe data access
• ‘on demand’ data retrieval or computation
• automatic consistency between related ‘Intervals of Validity’
• C++ object lifetime management

Client code does not need to be recompiled or relinked when
configuration changes
• Implemented using dynamically loadable components

Based on experience from CLEO
• expect the system to provide for all of CMS’s future needs
#241 – C.Jones, Access to Non-Event Data for CMS
Visualization
Commissioning
ATLAS Online
Histogram Presenter






OHP is an interactive
application developed to
present histograms produced
by ATLAS Online Monitoring
System
Is fully configurable (different
views of the produced
histograms, drawing options)
Can communicate with the
histogram producers sending
commands
Optimizes network traffic
Manages reference histograms
OHP will be used in the ATLAS
commissioning starting from
March 2006
#24 – A.Dotti, OHP: An Online Histogram
17 February 2006
Event Processing Applications summary
Presenter for the ATLAS experiment
39
Atlantis






Atlantis event display is a
stand-alone Java application
Uses variety of 2D projections,
multiple views (windows) on
canvas
A part of the ATLAS SW,
depends only on Java
Uses simplified detector
geometry (not a detector
display)
JiveXML (written in C++)
interfaces ATLAS SW
framework Athena (its event
store) and Atlantis
Access to the event data from
Atlantis
• using the event files produced
by JiveXML (offline)
• reading the event data over
network from JiveXML server
(online)
17 February 2006
Event Processing Applications summary
40
#33 – Z.Maxa, Event visualization for the ATLAS experiment – the technologies involved
CMS Cosmic
Challenge

The MTCC is a fundamental
milestone for the new CMS
software
• Global Data Acquisition with
(almost) all sub-detectors
• Data quality monitoring,
event selection and
streaming based on local
reconstruction
• Non-Event Data DB
infrastructure
• Offline global reconstruction
using alignment data

17 February 2006
CMS is on schedule to
achieve these goals
Event Processing Applications summary
41
#312 – G.Bruno, Software for the CMS Cosmic Challenge
CMS Data Quality
Monitoring




DQM for CMS Tracker is
very challenging due its
size and complexity
Tracker DQM software
exists with basic
functionality of the
producer and consumer
A simple and very useful
tracker specific visualization
tool, TrackerMap exists
along with a couple of
generic graphical user
interfaces
Important milestones in
2006:
• Cosmic Challenge (CMS
slice test with Cosmics)
17 February 2006
Event Processing Applications summary
#283 – S.Dutta, Data Quality Monitoring for the CMS Silicon Tracker
Few considerations …

Modular software and abstract interfaces
• Experiments frameworks (CMS, ILC, …)
• Reconstruction software

Collaborative software
• Share data and validation results


Usage of the GRID for simulation validation and
regression testing
Focusing on Alignment
• Track-based, optical
• Software is adapting, also simulation

Looks never too late for big revolutions or major
re-designs
• Power of Object-Oriented ? …
17 February 2006
Event Processing Applications summary
43
THANKS !
17 February 2006
Event Processing Applications summary
44