# Presentation: 224426

## ITTF StatusSTAR Analysis Meeting Dec 5, 04

- Claude Pruneau
- Wayne State University

## Last 12+ months:New Reconstruction Chain

- Goals:
- Integrate the new (ITTF) tracker in the STAR reconstruction chain.
- Eliminate obsolete/legacy code; e.g. tables .
- Use StEvent as object model both for processing and persistency.
- Integration/Development Team
- J. Balewski, **M. Calderon**, L. Didenko, **Y. Fisyak**, **B. ****Hippolyte**, **J. Lauret**, M. Oldenburg, C. Pruneau, **A. Rose. **
- Duration: ~ 7 months.

## BFC Changes and Improvements...

- ITTF Track Reconstruction (ITTF Team)
- Generic Vertex Maker (L. Barnby, J. Balewski, T. Ulrich)
- Façade/Interface deployed to enable multiple vertex finding algorithms.
- New Maker based on Minuit
- TPC cluster finder (DAQ Team: J. Landgraf, T. Ljubicic )
- Fast finder, re-written from scratch in C++.
- Kink finder (C. Mironov, S. Margetis)
- K reconstruction
- C++ re-write of FORTRAN code.
- TPC Hit Calibrations (J. Lauret)
- Coordinate transformation, calibration adjustment)
- Formerly entangled with old tracker TPT, now a new module “StTpcHitMover” .
- Addition of chain options for increased flexibility (J. Lauret, Y. Fisyak, M. Calderon)
- Module ordering no longer static, but predicated on components included in the Chain.

## Changes and Improvements...

- SVT Code
- Modified to use StEvent (the persistent data model) or tables.
- FTPC Code
- Modified to use StEvent.
- Trigger data detectors
- Formerly in StEventMaker, now part of a compendium maker
- Performance Evaluation Codes (J. Lauret, Y. Fisyak, M. Calderon)
- Included propagation Geant particle ID in hit/track reconstruction to dominant contributor evaluation (key to dominant, number of hits, avg quality).
- Generic track-track comparison maker was developed.
- Integration of SSD.
- R&D for a new pixel detector

## Performance Verification

- Goals
- Verify code integrity - produce sensible numbers
- Verify physics performance
- Tester team
*Representatives from each STAR Physics working group*
- Event structure - Aya Ishihara
- Spin - Jan Balewski
- HBT - _Zbigniew Chajecki_
- Heavy Flavor - Alex Suaide
- EbyE - Paul Sorensen
- Spectra - Johan E. Gonzalez, Alexander Wetzler
- High-pT - Marco van Leeuwen
- Strangeness - Sevil Salur. Camelia Mironov, Ying Guo
- Duration: June 16, 04 to September 22, 04.
- Hard work!
- Data samples reproduced 14 times.
- Multiple (minor) bug fixes.

## Performance Verification

- N

- Balewski

- d + Au @ 200 GeV.

- NFitPoint15, DCA ≤ 3 cm, |≤1.00, pt  0.40 GeV/c, FitPtefrac  0.55, Zvert ≤ 100.

- pt (GeV/c)

- Yield

- Yield

- pt (GeV/c)

- Mass (GeV/c2)

- A Wetzler

- Previous - Black

**New - RED**

- S. Salur

- J. E. Gonzalez

## Performance Review - HBT Analysis - Track Merging/Splitting

- d +Au data

- Previous

- New

- Zbigniew Chajecki

- Merging?

- Splitting?

- Zbigniew Chajecki

## Previous

- New

**BETTER!!!**

- Zbigniew Chajecki

## Status Statement- End of August

| ITTF Tracker | Completed! |
| --- | --- |
| Integration in Reconstruction Chain | Completed!  |
| Performance Comparison/Validation | Completed!  |

- Ready?

## Maybe not...

- Message from Marco van Leeuwen - Sept 24.
- “When looking at the express-stream production, I saw that there are still some primary tracks with helix origin at 'weird' values (r > 10m).”
- Another Message from Marco beginning of October.
- “Correlation global vs primary tracks is anomalous”

- TPT

- ITTF

## Reconstruction Bias & Resolution

- Primary +
**ITTF RED**
- TPT BLUE

**Reconstruction Bias & Resolution**

- Review - Aug 03.

## Reconstruction Bias & Resolution

- pt/pt>

- pt/pt)

- p(GeV/c)

- Primary +
**ITTF RED**
- TPT BLUE

- pt/pt)

- p(GeV/c)

**Occupancy**** **
**RED - Low**
**BLUE - High**

## Efficiencies vs pt

**Efficiencies vs p****t**

- Cuts :** N MC Hit > 10;  -1<********<1; DCA<3 cm**

- pt (GeV/c)

**ITTF **
**TPT**

**Low ****Multiplicity**

**High Multiplicity**

- 

- 

- pt (GeV/c)

## Closer Look at Code+Output

- Found many problems/bugs.
- Some primary tracks not going through beam pipe.
- Some tracks with negative chi2, others with negative track lengths, still others with points outside the fiducial volume of the detector.
- Apparent mis-alignment of the SVT.
- ...

## Status as of Dec 4, 04

- Special thanks to:
- Victor, Yuri, Jerome, Marco, Manuel, Duncan, Helen, Marcelo, ...
- Many bug fixes...
- Code review

## Some “good” news!

- Event-by-event track by track TPT vs Sti Comparative Analysis - Manuel

- Sti Fit Points

- Tpc Fit Points

## Momentum Resolution

- ptpt - pittf (GeV/c)

- Fit Points    Mean    RMS
-      15-25        0.004      0.05
-      25-35       -0.0007    0.04
-      35-45       -0.001      0.03

##  Relative Tracking Efficiency

- By doing  a comparison track-by-track, one can measure the relative efficiency of each tracker.
-  In the absence of ghost tracks, to first order the track populations seen by each tracker are
-  obtained from the same (unknown) track population

## Slide 19

## Slide 20

## From Marco’s Web Page - Addition Dec 3.

- With SVT

- Without SVT

## Vertex Position in the transverse plane

- Without SVT

##          “y” Residuals (pad row direction)

-          “y” Residuals (pad row direction)

- TPC 1                                                                           45

## SVT “y” (drift direction) Residuals

- y (cm)

- Inner Most Layer

- All tracks

- All tracks with 2 SVT hits

## 2nd SVT Layer

## TPC Only

- TPC+SVT

- From Duncan

- Primaries |eta|<1

## From Marco

## What’s next

- Code review + some further bug fixes in progress (Victor+Yuri)
- Completed soon.
- Further performance checks (Marco, Helen, Duncan)
- Is the SVT geometry OK, or Sti problem only?
- Some tuning - insure tracking parameters are optimal
- Large scale test and review (again?)