# PC-2016-04-15-emittance¶

Folks,

Can we have a get together on Friday to run through status of the

emittance paper since the collaboration meeting? I propose Friday at 14:00 BST, usual phone bridge

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

This would replace the regular diagnostics session on Thursday (no point in doing it twice). I think the questions we should target are:

**ROOT file of run 7469 (and MC) including the Rayner TOF momentum reconstruction:** http://micewww.pp.rl.ac.uk/issues/1833

- The low-level track reconstruction (everything up to pattern

recognition) should be written up ASAP. I think it is at a reasonable point?

- What dos the p-value distribution look like? Are the p-values not uniform if not, why not?
- What is the error on tracker recon introduced by the field non-uniformity?
- What is the error on tracker recon introduced by the disagreement between model and field maps cf: slide 3 of

https://indico.cern.ch/event/485764/contribution/2005672/attachments/1249829/1842249/fieldmapping.pdf

- Quantitative demonstration that EMR and TKU are consistent
- What is the source of the shoulder (low momentum particles under the muon TOF peak)? Is it partial scraping? Can we differentiate between bad track reconstruction for high amplitude particles (e.g. p-value) and "partial scraping"?

- Any results for likelihood-based PID?

- Track matching status?
- Jan: http://micewww.pp.rl.ac.uk/attachments/6079/7469-TMResiduals.png
- Rogers: http://micewww.pp.rl.ac.uk/attachments/6078/tku-tof-extrapolation-residuals_v2.tar.gz
- attachment:normalised_residuals_-_tof0_t.png
- attachment:normalised_residuals_-_tof1_x.png
- attachment:normalised_residuals_-_tof1_y.png

- Are the OPERA model and Hall probes consistent? How big are the

inconsistencies? - Continue trying to untangle the field mapping data for SSU

- data vs MC distributions - do we now have a reasonably correct description of the beam? Comparaison plots
- what are the residuals?

- Emittance calculation etc - any updates?

## Notes¶

Francois

Rogers

Durga

Scott

Jan

Joe Langlands

Tanaz

Chris H

Victoria

Chris R

### Scott¶

Muon shoulder:

TOF0 position vs TOF0 position shoulder particles- Note that the TOF0 position is double-peaked

- Discussion about tracker fiducial cut; fiducial cut is on the maximum radius of the track Chris Hunt thinks
- Scott noticed a bug with plot on slide 5
- Consider adding a plot showing particle radius at each of the principle physical volumes esp diffuser

- Francois points out that muons will look like pions in the EMR due to KL
- Note that "momentum difference" plot momentum difference is correlated with tracker momentum so comparison is not fair
- Consider abandoning EMR vs Tracker comparison and driving the MC to assess the PID quality instead
- MC can give efficiency; need to untangle this to generate a "prior" distribution

### Tanaz¶

- Looking at improving Ckov analysis to do PID, following discussion with Ckov experts - more next week

### Chris Hunt¶

- Recalculation of some matrices may not be done quite right
- Momentum reconstruction is now 0.5 MeV/c resolution
- P-value plots are heavily skewed in one direction; MCS is overestimated in tracker recon
- Restructuring measurement system to give it different measurement classes
- Rogers suggests MCS and dEdx routines should be checked in tracker paper

### Jan¶

- TOF0 time - note 30 to 50 mm; 0.1 ns offset in the mean
- Considering pz as conserved between TOF1 and TOF0
- Consider path length difference; may be source of the offset?

- Use Rayner analysis momenta; they are in VB's ROOT files
- Assumes muon hypothesis
- JG and VB to discuss

- Note that downstream tracker is not functioning in 7469
- TKD should not be used in 7469

### Victoria Blackmore¶

- Hall probes; not inconsistent, but need to understand the precise position of the hall probes wrt solenoid
- 4.05 3.8 4.08 4.05; sigma 34-36 muT; constant during the run
- Rogers notes script to extract field map from MAUS: bin/examples/get_field_map.py

### Francois¶

- ckovb pe looks inconsistent between MC and recon
- Why is the muon shoulder not in MC?
- tracker pz plot

### Blackmore - emittance¶

- Emittance matrix subtraction calculation - should be done

### Yingpeng¶

- Yingpeng is just starting to study beam ellipse matching

### Note status¶

- List of low level plots would be useful
- Tracker; everything up to PR is done
- PID and track matching from Melissa
- TOF efficiencies
- Emittance calculation
- IPAC 28th April
- ICHEP 31st May - paper deadline