Difference between revisions of "JLab discusion on tracking priorities, March 5, 2009"
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+ | == Discussion == | ||
General comment: We have three tracking efforts. How can we leverage the | General comment: We have three tracking efforts. How can we leverage the | ||
work to date? How do we move forward effectively? | work to date? How do we move forward effectively? | ||
Line 7: | Line 8: | ||
#* [[Media:fitter_summary.pdf|Mark]] | #* [[Media:fitter_summary.pdf|Mark]] | ||
#Issues impacting design/construction | #Issues impacting design/construction | ||
+ | #* Charge division in CDC | ||
+ | #** What does it buy us in pattern recognition or resolving L/R ambiguities? | ||
+ | #** How do connected wires add to ghost tracks? | ||
+ | #** Where and how many measurements are they needed? | ||
+ | #** On what time scale is this decision required (Jan 2010)? | ||
#* sensitivity to B-field | #* sensitivity to B-field | ||
− | #* wire configuration for FDCs | + | #** Timeline - summer 2009 |
− | #* assignment | + | #** Generate new fields given "reasonable" variations in (coil positions, magnetic properties of iron, fringe fields downstream and iron cladding) |
+ | #** key discriminators: momentum resolution, extrapolation to tof | ||
+ | #* staggering wire configuration for FDCs | ||
+ | #** Timeline - summer 2009 | ||
+ | #** help left-right assignment?(use fit to wire positions to see which configuration finds more L/R configurations) | ||
+ | #** note: impact is that the number of types of electronic boards doubles (x, x' are different) | ||
#* Effective size of forward hole (nominally 1 deg) | #* Effective size of forward hole (nominally 1 deg) | ||
− | #* | + | #** What is the effective angle in the current design at 1 GeV? |
− | #* | + | #** efficiency around hole in prototype |
+ | #** impact: artwork on cathode boards | ||
+ | #** positions of packages impacts effective angle | ||
+ | #** timeline - December 2009 | ||
#*...we need to complete this list | #*...we need to complete this list | ||
# Achieving a robust tracking program for single tracks (multiple scattering, energy loss and position resolution only) | # Achieving a robust tracking program for single tracks (multiple scattering, energy loss and position resolution only) | ||
Line 27: | Line 41: | ||
#* reference trajectory methods | #* reference trajectory methods | ||
#*... work on these to the extent that they impact studies 1-3. | #*... work on these to the extent that they impact studies 1-3. | ||
+ | |||
+ | == Proposal (Eugene) == | ||
+ | # Finalizing existing methods | ||
+ | #* Get ideal hit assignment | ||
+ | #*# determine resolutions, including sensitivity to B-field | ||
+ | #*# understand irregularities in efficiency and resolution | ||
+ | #*# demonstrate resolutions with Kalman filter are better under ideal circumstances than brute force fitters | ||
+ | # Ambiguity cleaning (determining correct L/R assignment) | ||
+ | #* procedure for reassigning L/R hits | ||
+ | #Reconsider best strategy for Hall D tracking | ||
+ | #* Review procedures from other experiments and mathematically "rigorous" tracking methods | ||
+ | |||
+ | Assignments: | ||
+ | # David: With correct L/R assignments compute resolutions (then study effect of B-field uncertainties) | ||
+ | # Mark: Investigate irregularities in current resolution and efficiency plots | ||
+ | # Simon: Demonstrate that Kalman filter improves resolution (in p and/or angles) in ideal cases. |
Latest revision as of 08:27, 16 March 2009
Discussion
General comment: We have three tracking efforts. How can we leverage the work to date? How do we move forward effectively?
- Short summary of current effort (~5 slides each)
- Issues impacting design/construction
- Charge division in CDC
- What does it buy us in pattern recognition or resolving L/R ambiguities?
- How do connected wires add to ghost tracks?
- Where and how many measurements are they needed?
- On what time scale is this decision required (Jan 2010)?
- sensitivity to B-field
- Timeline - summer 2009
- Generate new fields given "reasonable" variations in (coil positions, magnetic properties of iron, fringe fields downstream and iron cladding)
- key discriminators: momentum resolution, extrapolation to tof
- staggering wire configuration for FDCs
- Timeline - summer 2009
- help left-right assignment?(use fit to wire positions to see which configuration finds more L/R configurations)
- note: impact is that the number of types of electronic boards doubles (x, x' are different)
- Effective size of forward hole (nominally 1 deg)
- What is the effective angle in the current design at 1 GeV?
- efficiency around hole in prototype
- impact: artwork on cathode boards
- positions of packages impacts effective angle
- timeline - December 2009
- ...we need to complete this list
- Charge division in CDC
- Achieving a robust tracking program for single tracks (multiple scattering, energy loss and position resolution only)
- Not necessarily the "final" or best resolution
- High efficiency over all angles (~1-140, define definite boundaries in angle and momentum)
- Efficiency defined based on a reasonable cut on tracking Chi2.
- Studies must include transition between CDC and FDC.
- Goal: create efficiency and momentum resolution plots on log scales (p vs theta) for pions and protons.
- Studies of multi-track events
- Are there any developments here beyond improvements/refinement of 2.? as a function of events with multiple tracks?
- constraining the vertex?
- Refinements/optimizations of the tracking code
- Kalman filters
- reference trajectory methods
- ... work on these to the extent that they impact studies 1-3.
Proposal (Eugene)
- Finalizing existing methods
- Get ideal hit assignment
- determine resolutions, including sensitivity to B-field
- understand irregularities in efficiency and resolution
- demonstrate resolutions with Kalman filter are better under ideal circumstances than brute force fitters
- Get ideal hit assignment
- Ambiguity cleaning (determining correct L/R assignment)
- procedure for reassigning L/R hits
- Reconsider best strategy for Hall D tracking
- Review procedures from other experiments and mathematically "rigorous" tracking methods
Assignments:
- David: With correct L/R assignments compute resolutions (then study effect of B-field uncertainties)
- Mark: Investigate irregularities in current resolution and efficiency plots
- Simon: Demonstrate that Kalman filter improves resolution (in p and/or angles) in ideal cases.