Extra files/plots for the meeting this afternoon:
- data_test_tku_A_B.pdf -- plots that show what particles pass/fail which cuts for data.
- recon_test_tku_A_B.pdf -- as above, but for reconstructed MC
- 7469_emittance_meeting__04May17.pdf -- slides to discuss
Victoria Blackmore - VB
Ken Long - KL
Chris Rogers - CTR
Scott Berg - SB
Paul Kyberd - PK
Victoria presented slides 7469_emittance_meeting__04May17.pdf; we went through them one-by-one. I noted down questions on each slide.
Query about what cut 4 means - VB: clarified that cut 4 means Pattern Recognition returns 5 space points
SB: Is there a low pt cut to deal with inefficiency? VB: I have not considered it; PK: Tracker group is working to improve efficiency at low pt; VB: Could look at p-values of low amplitude tracks; KL: the tracker will not reconstruct low pt cuts at all, so p-values will not be considered
KL: where does the diffuser material start? VB: it is not surveyed in; but the radius is 100 mm, extending by about 50 mm in radial direction; can is outside the diffuser material; tracker fibres are outside the can; it is roughly 80 mm long; magnetic field on the diffuser aperture is at about 3 T.
Slide 4 "Diffuser Cut" showing TOF t vs tracker p¶
SB: Note that the TOF vs tracker banana may be wider in MC recon than MC truth; PK: would require further investigation to demonstrate it.
Slide 5 "Diffuser cut" showing different regions¶
SB: Note that you can look at MC truth for e.g. PID VB: yes this is on the next slide.
Slide 6 "Diffuser cut" showing radius vs number of events in Lower Junk¶
KL: note the width of the rising edge on the radius cut; SB: potentially explained by arbitrary nature of the lower junk zone cut - the "lower junk zone" may not exactly correspond to the events that strike the diffuser.
Slide 7 "Diffuser cut" showing radius vs number of events in Upper Junk¶
SB: ACTION: Tag the actual muons that went through the diffuser in MC; plot the position of pions on the banana plot
KL: Why do the number of particles in the "Lower" Junk Zone not add up to 4398? VB: not all events are listed in all columns
Slide 9 "Diffuser cut" showing extrapolation residual¶
KL: note bias in mean position residual (and the fact that it gets "better" by diffuser st 1); CTR: need to look at the momentum residual as well due to focussing
Slide 13 "Diffuser cut" showing outcome of different diffuser cuts¶
KL: Where are electrons? VB: < 27 ns for electron primaries KL: decay electrons could be anywhere VB: 4 out of 4000 in MC
KL: MC sample is relatively small ACTION get a bigger MC sample
Slide 15 "Data with selection"¶
KL: Note that there is some noise in data that is not so pronounced in MC
CTR: Note that magnet misalignment is in the data but not in MC
KL: Note that there are a significant population of good muons that are excluded by the cut; VB: the diffuser is not uniform; muons can traverse the diffuser without hitting material
SB: ACTION: Consider doing an amplitude cut? May remove some bias compared to a radius cut
Slide 17 "Phase space distribution x vs y"¶
SB: ACTION: worth slicing the phase space plots in momentum
Slide 21 "Emittance MC vs data"¶
PK: ACTION: make the vertical scale the same (or put both emittance diagrams on the same plot)
CTR: ACTION: try using Paolo's dipole fields for BL simulation
Slide 23 "7469 vs 8590" showing TOF01¶
SB: ACTION: Check mean calculation; judging by eye, it is not consistent
SB: Can we do combined fit using TOF and tracker amplitude; VB: note Mark Rayner analysis; SB: could be useful for low amplitude tracks; PK: 0 canonical angular momentum tracks are not rejected in current track fit routines
SB: It's a good analysis, but still have a lot of work to do
KL: Offered to help VB with some drafting
Summary of Actions¶
- ACTION: slice the phase space plots in momentum
- ACTION: get a bigger MC sample
- ACTION: Consider doing an amplitude cut rather than a radius cut?
- ACTION: Tag the actual muons that went through the diffuser in MC and show it in other plots;
- ACTION: plot the position of non-muons on the banana plot
- ACTION: on emittance - MC vs data - make the vertical scale the same (or put both emittance diagrams on the same plot)
- ACTION: try using Paolo's dipole fields for BL simulation
Date of Next Meeting¶
- Tuesday June 13th