h1. 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

h2. 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