Project

General

Profile

Kaon LT Meetings » mtg_22sep08.txt

Garth Huber, 09/08/2022 05:55 PM

 
1
                Sept 8/22 PionLT/KaonLT Analysis Meeting Notes
2
                ----------------------------------------------
3
                           (Notes by GH and SJDK)
4

    
5
Please remember to post your slides at:
6
https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings
7

    
8
Present:
9
Regina - Stephen Kay, Garth Huber, Vijay Kumar, Muhammad Junaid,
10
   Alicia Postuma, Jacob Murphy, Ali Usman, Love Preet
11
CUA - Richard Trotta, Tanja Horn
12
Ohio - Jacob Murphy
13
CSULA - Konrad Aniol
14

    
15
Richard Updates
16
---------------
17
- Lumi 10.6GeV Analysis
18
   - PID cuts updated
19
   - Scaler, Without, and with tracking cuts
20
   - Statistical uncertainties now too (but not yet including statistical from
21
     efficiencies)
22
   - Normalized yield results vs. Current for HMS-Carbon
23
      - Blue: total LT, red: CPULT
24
      - Scaler vs Event (no tracking) vs Event (tracking)
25
      - Large discrepancy between the two, with the CPULT results being MUCH
26
        better
27
   - SHMS-Carbon analysis shows "reverse boiling" of 14% @ 70uA
28
      - SHMS sees a trend even with poor TLT runs removed
29
   - Some Lumi runs are not great
30
      - <90 seconds of "good" beam on time after current cuts
31
      - Bi-modal distribution of current within some runs
32
      - GH note afterward: Yes, the 10.6GeV beam current was extremely
33
        unstable.  The 8,6GeV lumi scans should be much better!
34
   - some CPULT as low as 75%, possible due to excessive EDTM rates for some
35
     low current settings.  EDTM should have smaller effect in high current
36
     runs, where PS is set high
37
      - Jacob asks about CPULT eqn used.  Does it include Carlos' Poisson
38
        correction discussed in his thesis?
39
      - It sounds like the answer is No, but Richard should double-check
40
   - See large inverse boiling trend with scalers in some scans which goes away
41
     in untracked and tracked analysis
42
      - Bad scaler yields correspond with CPULT drops
43
      - This is *very* worrisome, as the scaler analysis should be insensitive
44
        to deadtime effects.  *Definitely* needs more investigation!
45

    
46
- Next up:
47
   - Offsets
48
   - Lumi analysis, cut iterations
49
   - HeeP/Lumi uncertainties
50
   - Bill's code
51
   - HeeP Singels efficiencies issues
52
   - Calorimeter Calibrations
53
   - HGC efficiency calculation
54

    
55
- Vijay: TLT vs CPULT, which should be used?
56
   - Dave G recommended CPULT previously
57
      - Generally fairly consistent between the two
58
   - Garth: EDTM system between KaonLT/PionLT, major difference between the two
59
     experiments.  This will be one of the causes of larger systematic error in
60
     KaonLT compared to PionLT
61
      - EDTM system updates were only ready for 2021 run, low Q2 PionLT (summer
62
        2019) still had the old verion?
63
      - As a result, the uncertainty in TLT might be too big to use in some
64
        parts of KaonLT, and we would have to use CPULT with a correction to
65
        account for Electronic DT
66

    
67
- FADC reference timing and CoinTime changes were done during the early parts
68
  of KaonLT, as deficiencies in the SHMS+HMS commissioning setup were identified
69
   - CoinTIme change was after the 10.6 GeV, but before the 3.9 GeV and 4.8 GeV
70
      - CT changes
71
      - Leading edge vs falling edge
72
      - Inverted signal
73
      - DaveG indicates (afterward) that this was error introduced summer 2018,
74
        were ALL reference time signals were inverted.  The main effect of this
75
        was crappy CoinTime resolution, as its more sensitive to jitter in
76
        signal timing
77
   - Hodoscope timing changes
78
      - Mark changed how the different hodoscope planes define the FADC reference time 
79
         - intial timing had each plane with a different time, with S1X last,
80
           leading to multiple peaks
81
         - later, after more understanding, the timing was changed so that most
82
           events are in a single peak
83
	 - DaveG thinks this occurred before J/Psi run in early 2019
84
      - All S1X were were synchronized by Simona at some point, to reduce
85
        timing jitter between different paddles
86
	 - this allowed the S1X, S1Y timing windows to be narrowed, which then
87
           helped reduce Electronic DeadTime (significant impact in some cases)
88
         - DaveG thinks this was done in summer 2018, before KaonLT
89
   - Someone should identify exactly when these confiugration changes occured
90
      - Ali will check, it would be helpful for Vijay to assist, since neither
91
        were present at the beginning of KaonLT data taking
92
      - Stephen skimmed the logbooks, some potential entries to look at (to begin with)
93
         - https://logbooks.jlab.org/entry/3629548
94
         - https://logbooks.jlab.org/entry/3630734
95
         - https://logbooks.jlab.org/entry/3630346
96
         - https://logbooks.jlab.org/entry/3614446
97
         - https://logbooks.jlab.org/entry/3614481
98
         - https://logbooks.jlab.org/entry/3626160
99
         - https://logbooks.jlab.org/entry/3626194
100
   - Could add issues to wiki once found?
101
      - There are status pages for KaonLT, Summer 2019 PionLT
102
      - Add information to this
103

    
104
Ali Updates
105
-----------
106
- High Q2 HeePCoin analysis
107
   - Ali/Richard looking at 6.2/8.2/10.6 GeV HeePCoin settings
108
   - Summarizes the Emiss/Pmiss distribution issues discussed last week
109
   - Debug Test #5
110
      - Stephen redid tests 1-4, discovered that files in high Q2 comparison
111
        test were different, confirmed that the problem is in hcana, not python
112
	script analysis
113
      - problem was a wrong gbeam.param file, which was for polarized 3He
114
        target data taking, where there is a large solenoidal field at the target
115
      - now have much narrower EM/PM peaks, which will allow the offsets to
116
        finally be determined from these data
117
   - Need consistent set of offsets
118
      - Momentum offset changes if the magnets saturate
119
      - Magnet settings for each beam energy
120
         - 10p6: p_h = -6.590, p_p = +4.484
121
         - 8p2: p_h = -4.672, p_p = +4.371
122
         - 6p2: p_h = -3.571, p_p = +3.486
123
         - 4p9: p_h = -3.124, p_p = +2.583
124
         - 3p8: p_h = -2.026, p_p = +2.583
125

    
126
- What is the correct gbeam.param file?
127
   - issue is that there are multiple versions of some variables in Vijay's
128
     version of the 2018 file
129
      - need to confirm that used file for KaonLT is correct
130
   - Dave G seemed to imply (offline) that this is the one should use:
131
      - https://github.com/JeffersonLab/hallc_replay_lt/blob/LTSep_Analysis_2022/PARAM/GEN/KaonLT_PARAM/gbeam_fall18.param
132
      - Implied we should use a different file altogether for Summer2019
133
      - possibly we need to generate a new one for PionLT 2021-22, from harp scan data
134

    
135
   - Emiss vs delta(HMS,SHMS) plots have a tilt (8.2 GeV setting)
136
      - Happened for all settings except 10.6 GeV
137
      - Should also add plot of HMS vs SHMS delta   
138
   - Tanja mentions we saw the effect of raster offset causing a MM vs delta
139
     correlation in Fpi2
140
      - error in raster correction causes an offset in vertical angle at target
141
      - strong correlation of angle vs momentum in Heep-Coin makes the effect
142
        visible in Heep MM vs delta
143
      - the error would be present also in the pi/K data, but the effect would
144
        be mostly in worse MM reconstruction resolution, not seen as a clear
145
       correlation, as this would be disguised by the 3-body (rather than
146
       2-body) kinematics
147
 
148
- How do we apply correct raster offsets?
149
   - In gbeam.param, beam on target positions are commented out?
150
   - Do these actually adjust anything? Should we set them to our nominal values?
151
   - Check and follow up with Dave G
152

    
153
- Efficiencies file
154
   - Run by run efficiency, propagated error should be statistical
155
     uncertainties that are added in quadrature to statistical uncertainty of data
156

    
157
Vijay Updates
158
- Working on Lumi studies, no updates
159

    
160
Junaid/Nathan Updates
161
- No updates, comprehensive preparation
162

    
163
Jacob Updates
164
- No big updates
165
- Lumi scripts + calibrations
166

    
167
Stephen
168
- Some discussion on topics to be discussed in October Hall C Analysis Meeting
169
   - meeting is planned to be ~2 hours long
170
   - 6 to 8 talks in total (GH thinks this might be too many)
171
   - Richard Lumi scan and Livetimes
172
   - Jacob EDTM and Prescale studies
173
   - Ali/Vijay gbeam.param
174

    
175
Next Meeting:
176
- Wed Sept 21 at 06:00 Pacific/07:00 SK/09:00 Eastern
(80-80/562)