EMCAL Offline Software

1
EMCAL Offline Software

• J.L. Klay
• Lawrence Livermore National Lab

2
Current Status
Most of the infrastructure is complete and
preliminary algorithms for the reconstruction are
in place. Particle identification software and
the calibration procedures/database interface
code need more manpower. The offline software
is being developed by a small team that is
currently co-managed by Gustavo Conesa Balbastre
at Frascati and Jennifer Klay at LLNL, with Bill
Mayes of University of Houston serving as
Calibrations Coordinator. We have a dedicated
discussion list (alice-emcal-offline_at_cern.ch) and
(semi-)monthly teleconferences. More dedicated
manpower is needed now to move the effort forward
at a pace that will allow the fast turnaround
from first data to first physics.
Some of the current players Alberto Pulvirenti,
Guenole Bourdaud, Cynthia Hadjidakis, Gustavo
Conesa, Jenn Klay, Joern Putschke, Magali
Estienne, Alexei Pavlinov, Marco van Leeuween,
others
3
Geometry

• A mostly final geometry has been implemented,
  subject to minor modifications as the new
  prototype is developed.
• Geometry software is complete and workable for
  now.
• 102x0.5 Supermodule EMCal is included in the
  PDC06 simulations (Trd1)

Documentation of EMCal setup and some accessor
methods still to be completed
4
Data Structures

• EMCal data structures for raw, reconstructed and
  event summary data (ESD) have been defined and
  are in use within the PDC06.
• ESD has reconstructed clusters and
  Pseudoclusters, which are structures that hold
  all tower ADC info for EMCal -- re-calibration,
  jet energy backgrounds, etc.
• ALICE would like us to utilize root-ized data
  structures for future testbeam and cosmic
  calibrations
• Final raw data structures must be defined and
  the mapping of raw data stream to offline
  structures (electronics channel number to ALICE
  offline numbering) has not yet been implemented.
• Data I/O adheres to ALICE standards.

5
Simulation

• Simple creation of detector digits from
  simulated hits is implemented. (Hits2Digits,
  Hits2SDigits)
• Once the electronics are finalized, the APD and
  FEE response parameters must be applied to
  correctly transform simulated hits to detector
  digits.
• Algorithm to convert simulated digits to raw
  data format for full reconstruction has been
  implemented. (Digits2Raw)
• How do we want to incorporate embedded simulated
  signals with raw data? (Raw2SDigits)

6
Alignment

• Alignment data for the supermodule locations has
  been implemented with placeholders to be replaced
  by survey data after installation.
• Code for testing reconstruction from misaligned
  supermodules in simulations is implemented.
• Updates to utilize global alignment algorithms
  (AliAlignObj, etc.) to be checked in soon (JLK).

7
Calibrations

• EMCal calibration data requirements and
  parameter sources defined and submitted to the
  ALICE Offline Board.
• Pedestals
• Energy scale from physics (MIP, electron pi0)
• Relative tower gain from LED
• Environmental variables (APD voltage,
  Temperature, etc.)
• Calibration data structures for pedestal/energy
  calibration have been defined with placeholder
  values.
• Connection with the ALICE online and database
  framework (SHUTTLE) have not yet been initiated,
  but volunteer (Gustavo) will start work on it
  soon.
• No calibration strategies nor procedures to
  derive real constants from data have yet been
  defined or implemented.

8
Trigger

• Code to generate EMCal trigger signals
  (following PHOS) from data has been implemented.
• Trigger performance should be studied with data
  from PDC06 and additional simulations of PbPb
  collisions to optimize EMCal trigger definitions.

Many synergies with PHOS have made EMCal software
easier -- adapted code
9
Reconstruction

• A first iteration EMCal clusterizer using
  nearest neighbor clustering has been implemented.
  
• Reconstructed clusters are stored in the AliESD
  structure for analysis.
• Pseudoclusters and Clusterv1 available in ESD
• Preliminary cluster/track matching is almost
  complete. Code will be checked in soon (days) --
  electron id/cluster matching studies should
  begin.
• After testbeam studies of the final EMCAL design
  are complete, reconstruction of simulated data
  should be matched to testbeam results.

10
Particle Identification

• Preliminary ?/hadron discrimination algorithm
  based on cluster size exists.
• Cluster shape fitting for particle
  identification needs to be implemented and
  optimized.
• Electron identification requires track matching,
  which is now nearly ready, volunteers?
• Preliminary invariant mass algorithm for ?0
  identification is implemented, but cut
  optimization for different ?0 opening
  angles/transverse momentum regions is still under
  study.

Lots of PDC06 data to be evaluated
11
Analysis

• No simple analysis algorithms, e.g. such as for
  extracting particle spectra for RAA studies, have
  yet been attempted.
• Cone jetfinder algorithm with background
  subtraction methods for heavy ion collisions has
  been written and detailed studies of the EMCal
  fast ALICE tracking have been performed, more
  studies under way
• Jet-splitting corrections for the cone jetfinder
  are done, further evaluation needed.
• Evaluation of the performance of FastJet, a kT
  jetfinder based on geometric nearest neighbor
  clustering for large multiplicity environments,
  using the EMCAL clusters and ALICE tracking in
  the works, needs more people

12
Whats needed now (FY07)?

• Reconstruction
• Work on track matching, PID electrons, ?/h
  discrimination, ?0 finding with PDC06 data
• Analysis
• Get jetfinder ready for charged only analysis
  to be used with next years pp data (use PDC06
  data now)
• Work on electron analysis with ALICE tracking
  and TRD, study track-matching to EMCal clusters
  and electron tagging within jets with PDC06 data
• Calibrations
• Prepare for/analyze new testbeam data (also
  within AliRoot framework)
• Prepare for cosmic calibrations data in ALICE
  format and develop cosmic calibration software
  within AliRoot (avoid duplicated effort)
• Implement MIP calib placeholder
  tables/constants in DB using cosmic calibrations
• Implement tables/constants for dead areas, hot
  towers, etc. in DB with procedures/code for how
  to fill/use them
• Simulations
• EMCal embedding procedure within existing
  AliRoot framework
• Trigger
• Study trigger with PDC06 pp data using
  existing software, revise as needed

13
User environment
On pdsf, multiple software versions available to
users
/common/alice/AliRoot old --gt v4-04-11
pro --gt v4-04-Release (PDC06) new --gt
v4-04-Rev-08 (PDC06 with updates/bug fixes)
HEAD (updated nightly) /common/alice/geant3
v1-5 v1-6 /common/alice/fluka
v2005-6 /common/alice/root v5-11-02
v5-11-06 v5-13-02
Picks the pro version by default
To get ALICE environment source
/common/alice/alisetup.csh source
/common/alice/alisetup.csh ltversiongt source
/common/alice/alisetup.csh ltversiongt ltwrkdirgt
Useful if you have your own development directory
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What youll see
pc2602 57 source /common/alice/alisetup.csh
----
--------gtWelcome to ALICElt------------- Currently
available software versions are
new--gtv4-04-Rev-08 (Updated PDC06 release)
pro--gtv4-04-Release (PDC06 release)
old--gtv4-04-11 (Older stable release)
HEAD (nightly rebuilt version) Please make sure
your environment is set for gtScientific
Linux (sl302)lt
Setting up default ALICE
environment ltIgt------------Info-----------------ltI
gt Setting up the following environments ROOT
/common/alice/root/v5-11-06 ALICE
/common/alice/AliRoot/pro ALIEN
/common/alice/alien FLUKA /common/alice/fluka/v2
005-6 GEANT3 /common/alice/geant3/v1-5/root_v5-1
1-06 CVSROOT pservercvs_at_alisoft.cern.ch/soft/
cvsroot ltIgt------------Info-----------------ltIgt pc
2602 58
15
Development option
If you are going to write software for the EMCal,
youll want to set up your own development area,
but you dont want to check out/compile all of
AliRoot We have a development script that will
help you set up a working area
source /common/alice/setupEMCALDev.csh ltversiongt
ltwrkdirgt
You only need to do this once, then whenever you
log in, just set up the environment to point to
your working area
source /common/alice/alisetup.csh ltversiongt
ltwrkdirgt
16
setupEMCALDev.csh
pc2602 51 cd work/test2/ pc2602 52 source
/common/alice/setupEMCALDev.csh new . ltIgt Saving
old LD_LIBRARY_PATH and PATH settings ltIgt Setting
up base AliRoot version
------------gtWelcome to
ALICElt------------- Currently available software
versions are new--gtv4-04-Rev-08
(Updated PDC06 release)
pro--gtv4-04-Release (PDC06 release)
old--gtv4-04-11 (Older stable release)
HEAD (nightly rebuilt version) Please make sure
your environment is set for gtScientific
Linux (sl302)lt
ltIgt------------Info---------------
--ltIgt Setting up the following environments
ROOT /common/alice/root/v5-13-02 ALICE
/common/alice/AliRoot/new ALIEN
/common/alice/alien FLUKA /common/alice/fluka/v2
005-6 GEANT3 /common/alice/geant3/v1-6/root_v5-1
3-02 CVSROOT pservercvs_at_alisoft.cern.ch/soft/
cvsroot ltIgt------------Info-----------------ltIgt
17
setupEMCALDev.csh (contd.)
ltIgt Creating the working directory ltIgt Linking
all common AliRoot files here ltIgt Removing link
for library (we need a local file here to contain
the new EMCAL library) ltIgt Removing link for
include (we need a local one here for clean
compiling) ltIgt Removing link for bin, (we need a
local copy of the aliroot executable) ltIgt Making
a local bin directory ltIgt Removing the link to
the CVS directory (we need a local one to
check-out files) ltIgt Removing link to ALIROOT
subdirectory (maybe this is not really necessary,
but we do it just to be on the safe side) ltIgt
Copying ALIROOT files from the local ALICE_ROOT
(or get from the cvs server afterward, of you
prefer) chmod failed to get attributes of new'
Too many levels of symbolic links ltIgt Removing
link for EMCAL subdirectory (we need to put the
real files here) ltIgt Copying EMCAL files from the
local ALICE_ROOT (or get from the cvs server
afterward, if you prefer) ltIgt Creating library
directory ltIgt Linking all common libraries
here ltIgt Removing link to EMCAL library, we will
compile our own ltIgt Fixing ALICE Environment
variables
------------gtWelcome to ALICElt-------------
Currently available software versions are

18
setupEMCALDev.csh (contd.)
new--gtv4-04-Rev-08 (Updated PDC06
release) pro--gtv4-04-Release (PDC06
release) old--gtv4-04-11 (Older stable
release) HEAD (nightly rebuilt
version) Please make sure your environment is
set for gtScientific Linux (sl302)lt
ltIgt------
------Info-----------------ltIgt Setting up the
following environments ROOT
/common/alice/root/v5-13-02 ALICE
/eliza5/alice/jklay/work/test2/new ALIEN
/common/alice/alien FLUKA /common/alice/fluka/v2
005-6 GEANT3 /common/alice/geant3/v1-6/root_v5-1
3-02 CVSROOT pservercvs_at_alisoft.cern.ch/soft/
cvsroot ltIgt------------Info-----------------ltIgt

Just cd to ALICE_ROOT,
compile with gmake, and type rehash. You should
be all set.
pc2602
53
19
AliRoot Resources

• Peter Hristov (and others) have put together a
  document that can help you get started
• http//aliceinfo.cern.ch/Offline/AliRoot/primer.ht
  ml
• How to set up the detector configuration/Monte
  Carlo generator
• How to run a simulation
• How to do reconstruction
• How to perform an analysis on the ESD (Event
  Summary Data)
• The Offline webpages have also improved quite a
  bit and provide lots of details
• http//aliceinfo.cern.ch/Offline/
• And of course, there are the mailing lists
  alice-emcal-offline_at_cern.ch, alice-off_at_cern.ch