2017-12-06-emittance » History » Revision 2

Revision 1 (Rogers, Chris, 06 December 2017 16:49) → Revision 2/3 (Rogers, Chris, 06 December 2017 16:50)

h1. 2017-12-06-emittance 

 Emittance paper 

 * Ken Long 
 * Chris Hunt 
 * Victoria Blackmore 
 * Chris Rogers 

 We started working our way through the emittance paper 
 * KL noted that it's time to standardise the cuts 
 * CR noted need to remove "0" space points line from the TOF "number of space points per trigger" plot (*Action VB*) (Action VB) 
 * CR noted the tracker butterfly as a possible aperture cut (*Action VB*) (Action VB) 

 * Discussed handling of low pt tracks in TKU recon 
 * CH described the track fit algorithm using TOF01 as a seed and he has a preliminary code; CR notes that this comes before global recon; so diffuser cannot be managed well; CR notes that multiple/deficient space points are not well-handled; this is all okay as it is consistent with VB cuts. Agreed that CH will pass preliminary reconstructed datasets to VB for analysis (*Action CH*) (Action CH) prior to code release in mid-December 

 * Discussed handling of field/momentum scale 
 ** KL: the hall probe calibration was done very carefully; so we believe the field measurement; the position has greater uncertainty; will be addressed during decommissioning phase 
 ** Plan to scale the tracker field to the hall probes and redo the reconstruction; assume that this is sufficient (*Action CH/DR*) (Action CH/DR) 

 * Discussed handling of tracker chi2 
 ** CR: check the straight tracks MC vs data; that validates the scattering model and hardware construction (Action CH) 
 ** Doesn't validate the field model or the energy loss 
 ** Then we move on to the helix; this is indicative of the field and energy loss 
 ** CH notes that he does see a difference between different energy loss models 
 ** Investigate different tracker alignments and field models 
 ** Note we still have to check the dead channel map is properly simulated 

 * Discussed discrepancy between MC momentum and tracker momentum 
 ** VB: Reweight based on momentum measured in TOF using Rayner (*Action VB*) (Action VB) 

 Note that still need quantitative estimate of the uncertainty involved in the reconstruction (*Action VB*) (Action VB) 

 Reminder for referee's meeting on Monday 16th January