[Hps-analysis] [EXTERNAL] SVT Hit time studies

[Nelson, Timothy Knight]

Hi All,

As Omar has pointed out, we need to make sure we are comparing apples-to-apples in considering hit time resolutions for different run periods.  It may be useful to consider the definitions that Matt Solt put in place, which I believe are represented in these studies.

https://urldefense.proofpoint.com/v2/url?u=https-3A__confluence.slac.stanford.edu_display_hpsg_Cluster-2BAmplitude&d=DwIFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=JaSEOiNc_6InrJmbYDvKU2tZqhhONpIkbyl_AUnkDSY&m=4nIUlP3_P6nj90_O1Wp2XV8zplHm8MIVNo3GH1uROif1I31_tX0YbA-FZhkm2GtH&s=tn7Sjp_PhFJ6e3oCA-fZBbtnMe9QhGWrnRVhGa7MMKQ&e= 

resulting in the plots here:

https://urldefense.proofpoint.com/v2/url?u=https-3A__confluence.slac.stanford.edu_download_attachments_232086427_fullFixedHitTime6.30-5Fhittime.pdf-3Fversion-3D1-26modificationDate-3D1530393740000-26api-3Dv2&d=DwIFAg&c=CJqEzB1piLOyyvZjb8YUQw&r=JaSEOiNc_6InrJmbYDvKU2tZqhhONpIkbyl_AUnkDSY&m=4nIUlP3_P6nj90_O1Wp2XV8zplHm8MIVNo3GH1uROif1I31_tX0YbA-FZhkm2GtH&s=E1kTLswRCam_XDTeJkotAYF65qE0CLy9NUJlOPAdfuc&e= 

In any case, we definitely should not have a delta_track_time cut for track finding that is wider than our delta_hit_time cut for clustering, which has been the case in the past.  Maybe the reasoning was to more effectively split clusters that are close in time?  I suppose one can assess S/B of a cut here by comparing the flat piece under the delta_time peak, where there is clearly some cost to admitting background.

Best,
Tim