CALICE Software Review: Introduction

1
CALICE Software Review Introduction

• Paul Dauncey

2
Some background to the review

• CALICE has made, or is planning, several physics
  prototype calorimeters
• Silicon-tungsten (Si-W) electromagnetic
  calorimeter (ECAL)
• Scintillator-tungsten (Sc-W) ECAL
• Scintillating tile analogue hadron calorimeter
  (AHCAL)
• RPC digital hadron calorimeters (DHCAL)
• Scintillating strip tail catcher and muon tagger
  (TCMT)
• These have been tested in beams over the last two
  years
• The first run was at DESY in spring 2006 with
  just the Si-W ECAL
• The AHCAL and TCMT were added in summer 2006 for
  the CERN runs
• These systems were extended to be more complete
  for the 2007 CERN runs
• The Sc-W ECAL ran at DESY early in 2007
• It is assumed that we will run in FNAL in 2008/9,
  comparing the ECALs, and the AHCAL and DHCAL, all
  run with the TCMT
• In the second half of 2009, there are likely to
  be further beam tests involving ILC-like
  technical prototype calorimeters
• The analysis of all these data is likely to go on
  beyond the end of the decade

3
The need for an analysis model

• Initially, when only ECAL data were available,
  the central software was mainly written by a
  small group (essentially Roman and Götz Gacken)
  working closely together
• This allowed an informal model to be created
  through discussion between them
• There was no particular need to document it
• Since the AHCAL and TCMT became involved and the
  analyses of the data became much more
  sophisticated, then the number of people involved
  has increased significantly, by at least an order
  of magnitude
• This led to an increasing proportion of Romans
  effort being taken handling individual requests
  for information, checking code submissions,
  processing data runs, etc, effectively saturating
  his time.

4
Some definitions

• Central ILC code LCIO, LCCD, Marlin,
  Mokka/GEANT4, etc, code written outside of the
  collaboration
• Not specific to CALICE requires requests to
  other developers for changes
• Can lead to significant time from identification
  of need to implementation
• Reconstruction process of producing the reco
  files from the raw data files
• In bulk, usually done centrally by expert(s)?
• Experts or semi-experts contribute code
• Some user studies are done on raw data (e.g.
  calibrations) those are also considered to be
  reconstruction for this review as the results are
  used for reconstruction
• Digitisation conversion of SimXxxHits in
  Mokka files to something which can be used by
  reconstruction
• Usage and comments as for reconstruction
• Usually run as part of reconstruction jobs for MC
  events
• Analysis studies done on reco files
• Usually done by semi- or non-experts

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How we hoped to improve the structure

• Make the reconstruction much more idiot-proof
• So idiots like me can run it without messing
  up...
• This should allow reprocessings to be handled by
  other people
• Centralise the MC production, digitisation and
  reconstruction
• Remove (most of) the need for user MC
  generation/reconstruction
• Release standardised files for direct comparison
  with data
• Make access to (particularly conditions) data
  more streamlined
• Different developers have implemented different
  solutions
• Try to standardise so users only have to learn
  one access route
• Make the connection with the ILC detector studies
  more transparent
• Use what we learn from the data, both within ILD
  and SiD
• An analysis questionnaire was circulated to
  collaboration over the summer
• To find out what is difficult, what works well,
  what is needed for the future, etc, so we could
  hope to improve these things
• I hope we will have some discussion of the
  findings later

6
The Charge to the Review Committee

• The CALICE collaboration is studying calorimetry
  for ILC detectors. The collaboration has acquired
  a large dataset from calorimeter beam tests in
  2006 and 2007 and expects to approximately double
  this during 2008. The total dataset so far is
  around 300M events, occupying 25TBytes. The
  dataset has significant complexity, being taken
  at different locations with differing beam
  conditions, energies and detectors.
• The ILC detectors have been charged with
  producing Letters Of Intent by Oct 2008 and
  initial Engineering Design Reports are expected
  by 2010. Hence, it is imperative that the
  collaboration extracts results from these data
  and publishes them in a timely manner. However,
  it is also expected that the final analyses of
  all the data will not be complete until three or
  four years from now.
• The main aim of the data analysis is fourfold.
  Firstly, it is to measure the performance of the
  prototype calorimeters used in the beam tests.
  Secondly, it is to compare Monte Carlo models
  with data so as to measure the degree of accuracy
  of the models. Thirdly, it is to apply the
  knowledge gained so as to optimise the ILC
  detector calorimeters with a verified, realistic
  and trustworthy simulation. Fourthly, it is to
  develop calorimeter jet reconstruction algorithms
  and test them on real data as well as simulation.

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The Charge (Cont)

• A significant offline software structure has
  already been put together to accomplish these
  aims, built on a previously determined conceptual
  model. The purpose of the review is to examine
  the implementation of this structure and comment
  on whether it does (or can in future) meet the
  aims of the collaboration. Some important points
  are
• If missing or ineffective areas can be
  identified, the review should suggest possible
  solutions or alternatives.
• Recommendations to streamline the reconstruction,
  simulation or analysis of the data, to save
  effort or time, should be made.
• The review should examine how well suited is the
  structure for the connection to the longer term
  detector studies and the development of jet
  reconstruction algorithms.
• Comments on whether the organisational structure
  is appropriate would be useful.
• There are limited numbers of people involved in
  the collaboration and so any recommendations from
  the review need to made with this in mind. In
  particular, some aspects of the software
  structure, such as the use of general ILC
  software, are probably too widely used to be
  realistically changed at this point. However, as
  a major user of the central ILC software, our
  experience should be useful to help improve it.
  If the review identifies constraints or
  bottlenecks arising from the use of this central
  software, comments on these would very welcome.

8
The Review Committee

• The members of the Review Committee today are
• David Bailey (Manchester)
• Günter Eckerlin (DESY)
• Steve Magill (ANL)
• George Mavromanolakis (Cambridge/FNAL)
• Vishnu Zutshi (NIU)
• I will act as organiser, provocateur and review
  secretary
• The process will be
• Go through the various aspects of the analysis
  model
• Meet to discuss the views and recommendations of
  the committee
• Present some preliminary feedback at the end of
  the afternoon
• Draft a written report over the next few weeks
• Present this to the Technical Board in early 2008