Diagnostics¶

There will be an analysis/diagnostics meeting Thursday 26th November, 14:00.

We will be in one of the usual meeting rooms in the Atlas building, using phone:

http://mice.iit.edu/phonebridge.html

• Optics review
• Tracker resolution and efficiency - Tracker Group
• Tracker-to-tracker alignment - Melissa/Chris Hunt/John Nugent
  • Tracker Survey
• Tracker alignment to field - Chris Rogers/Sophie
• Cut-based beam selection vs 2015/01 data - Tanaz/Scott Wilbur
• Ckov momentum scan - Ao, Durga
• Full PID vs 2015/01 data - Celeste
• PID detector alignment - Francois
• Detector Efficiencies - Jan/Francois
• Paper: High precision measurement of emittance - Chris Hunt/Victoria
• Date of next meeting
  • 10th December
  • 17th December - if we have data in the meantime

Notes¶

Durga Rajaram
Chris Rogers
Francois Drielsma
Adam Dobbs
Scott Wilbur
Chris Hunt
Tanaz Mohayai
John Nyugent
Ed Overton

Tracker resolution and efficiency (Chris Hunt)

• Took a step back from the alignment stuff following CM due to tracker geometry issues
• Fixing data structure, analysis scripts
• Main issue is pz resolution and systematic mismeasurement
  • Bug that has been floating around for quite a while
  • On the order of 1-2 MeV/c in MC
  • Looks like energy loss calculations were incorrect for some reason
  • Gradient of energy loss was different in MC and MC recon
  • But the error is more significant in data
• Likely causes
  • Field non-uniformity
    • Field drop-off is around the TRP
    • Rogers notes there is also a 1-2 mrad misalignment
    • Rogers notes there is a miscalculation in MAUS due to the iron
  • Subtle issues with Kalman algorithm
    • Kalman is inherently linear
    • Helix is inherently non-linear
    • Helix is correct to first order
    • SciFi is made of fibres
    • Energy loss in Kalman is done "outside" the algorithm and hacked into Kalman;
    • energy loss is not tied into the smoothing step due to the funny way the propagator is done
    • Paul Soler notes parameterising energy loss as a polynomial fit worked okay, paper written and published
• Durga asks what is the effect in < 4 T data
• Chris Hunt notes that he can do the work but could be helped by spreading round some of his other responsibilities

Tracker-to-tracker alignment

• Tracker alignment meeting; update on how things are going
• Some useful suggestions

PID plots (Scott)

• See slides
• Note that there is additionally a transverse (momentum dependent) distribution; try taking a fiducial cut on e.g. the central bar

PID plots (Tanaz)

• Working on modifying existing code for cut-based analysis
• Produce an output for the PID based on different detectors
• Note TOF is not trivial