Integrated Tracker Task Force Review


This document is meant to help the Integrated Tracker Task Force (ITTF) review committee in their task.



Introduction/History


As the STAR experiment evolved, its detector system was upgraded with several new sub-systems to enhance tracking precision and/or to enhance our ability to search for secondary particles. It soon became clear that a new tracking approach was required in order to fully take advantage of the information provided by all sub-systems. In fact, while the current approach of tracking in the TPC-only was found to be adequate at the previous review (June 2000), and indeed, has proven to be tremendously successful in the processing and analysis of the past year's data, the same review commitee recommended the formation of an R&D group to start work on an integrated tracking scheme. A call for investigating new algorithms for road-finding and track extrapolation (as the two main example topics) was made and the Integrated-Tracking Task Force (ITTF) was formed to achieve this goal. The initial tasks for the group were to produce a tracker for STAR that


  1. provides highly efficient and minimum-contamination information on particles emitted into the STAR acceptance.

  2. incorporates all tracking detectors taking into account their detailed geometry, calibration, material location and thickness, as well as magnetic field effects.

  3. provide also tools which allow to extrapolate from one position on the track to any other position along the flight path of the particle with high accuracy (track extrapolation).



The effort is lead by Claude Pruneau from Wayne State University. Since several experiments have worked on this subject in the recent past and solutions have been developed and implemented by ALICE, Atlas and BaBar (to name but a few), it was pointed out that the group may consider the re-use of such existing code or algorithms were applicable and justified. However, freedom in the choice of approach was given and the ITTF members only had to follow some basic guidelines such as




Requirements for the STAR Integrated Tracker (STI)


The ITTF members were give a set of guidelines as well as requirements on several front. They will be described in this section.


Functional Requirements


  1. Track finder/reconstruction

  1. Track Fitting

  1. Geometry

  1. Data Store


Performance Requirements




Code and Language Requirements




Committee Charges



At the end of the set of presentations by the ITTF members and STI testers, the review committee should be informed on and be able to comment on the following items :


  1. The general code design. In particular, but not limited to,

  1. The state of the geometry implementation and treatments of energy loss and multiple scattering.

  2. The STI tracker’s efficiencies and the global tracking performance (as per the original Performance Requirements specified above)

  1. Integration plans and global tracking feasibility for final implementation

  1. The STI readiness and suitability to replace the current STAR tracker.



In addition from reporting on the above issues, the review committee is invited to address the following items as needed:


  1. Any unforeseen tracking issues inherent to the new approach and make recommendations for possible improvements and accounting of items not addressed in the review presentations.

  2. Identify any tracking issues not addressed in either the current or the STI tracker but which need to be taken into account in future upgrades and developments.

  3. Comment and suggest improvements or other tracking methods/models.



The review committee is asked to return their written report within two weeks following the review to the STAR Software and Computing leader.




The review committee


The review committee will be composed of the following members :


Rene Bellwied

WSU

Chair

Alexandre A. P. Suaide

WSU


Bernd Surrow

BNL


Helen Caines

Yale


Iwona Sakrejda

LBL


Jan Balewski

Indiana


Mike Lisa

OSU


Thomas Ullrich

BNL


Yuri Fysiak

BNL





Alan Poppleton

CERN / Altas


Karel Safarik

CERN / Alice





David Hardtke

LBL

ex-officio

Jamie Dunlop

Yale

ex-officio

Jerome Lauret

BNL

ex-officio

Jim Thomas

LBL

ex-officio

Morton Kaplan

CMU

ex-officio

Tonko A. Ljubcic

BNL

ex-officio





Developers and Testers


The ITTF was composed of



Testers who have made this effort possible are




This document is available at

http://www.star.bnl.gov/STAR/comp/meet/ITTFReviewSept2002/ITTF-review-charges.html

http://www.star.bnl.gov/STAR/comp/meet/ITTFReviewSept2002/ITTF-review-charges.ps