Project

General

Profile

Kaon LT Meetings » mtg_23oct03.txt

Garth Huber, 10/03/2023 07:22 PM

 
1
                 Octt 3/23 PionLT/KaonLT Analysis Meeting Notes
2
                 ----------------------------------------------
3
                            (Notes by GH, AH & RT)
4

    
5
                     Today: KaonLT will be discussed first
6

    
7
Please remember to post your slides at:
8
https://redmine.jlab.org/projects/kltexp/wiki/Kaon_LT_Meetings
9

    
10
Present
11
-------
12
Regina - Alicia Postuma, Muhammad Junaid, Nacer Hamdi, Nathan Heinrich,
13
   Vijay Kumar, Garth Huber
14
CUA - Richard Trotta
15
FIU - Pete Markowitz
16

    
17
Richard
18
-------
19
Q2=2.1 R=Data/SIMC plots vs phi for t-bins at low, high epsilon
20
- Sync the range of angles between SIMC [0, 2Pi] and hcana [-Pi, Pi]
21
  - added pi to hcana phi
22
- high ratios at phi=240,280 deg consistently for all 3 t-bins, SIMC events go
23
  to zero for these bins
24
  - unweighted distributions show events in these bins, so it is presumably a
25
    weighting issue
26
  - sigTT is calculated way too large for some bins as well
27

    
28
- using starting parameters from LD+ Fpi-2 analysis
29
  - no changes to t-average calculation yet
30
  - m_pi pole factor not yet modified for m_K
31
  - no (Q2,W) scaling appiled yet to leading parameters
32
    - this may solve the issue, the important thing is to estimate a set of
33
      initial starting parameters that behave reasonably, Richard will need to
34
      do a by-hand calculation to find them
35

    
36
Some high epsilon data have two slightly different TH_shms, e.g. some right
37
setting data were taken initially and came back to take more statistics later,
38
the TH_shms differ slightly between the two sets
39
- Garth: for the experimental data, need to select the right angle for each run
40
  number in standard.kinematics
41
  - for SIMC, if the difference is small (typically 0.005deg), run SIMC using
42
    the mean angle of the data (weighted by the accumulated beam charge)
43

    
44
Still running Heep for offset check
45
- getting ifarm replay errors: SLURM FAIL
46
- Nathan also has ifarm issues since Friday
47
- will follow up with IT tomorrow
48

    
49

    
50
Vijay
51
-----
52
Sent Heep plots for new offsets to GH yesterday
53
- looking at comparison of tar and spectrometer variables between data and SIMC
54
  after reconstruction script
55

    
56
Lumi studies will start son
57
- low current BCM calibs are very important to the low Q2 data!
58

    
59
Nathan
60
------
61
Hodscope calibration ongoing (V_prop 2021 data)
62
- met w/Junaid to explain the calibration process
63
- batch errors lead to slowing calibration jobs
64

    
65
Junaid
66
------
67
Helping Nathan with Hosdoscope calibration (V_prop 2022 data)
68
- was using Stephen's old scripts, now switched to new scripts
69
- one of the points of NH and MJ work is that we don't know how many different
70
  sets of V_prop will be needed, so need to calibrate a selection of all data
71
  to study parameter stability
72
  - V_prop is a whole matrix, so many more parameters than time offsets
73
- using interactive so far for script testing, so not yet delayed by ifarm
74
  issues
75

    
76
Alicia
77
------
78
HGC vs. Aerogel Cherenkov NPE (10.6 GeV data)
79
- Noticed negative NPE in the HGC! 
80
  - 2D plot of HGC vs Aero
81
    - events w/ HGC npe<0 but Aero having 5-20 npe
82
  - needs some investigation of the HGC calibration for these runs
83

    
84
- Vijay quickly confirms that HGC calibrations for 10.6 GeV data were done for
85
  runs 4875-5325
86
  - first step is for Alicia to confirm that she is using the correct
87
    calibration files
88

    
89
Nacer
90
-----
91
- going through event selection & variables for low Q2 KaonLT data
92

    
93
---------------------------------------------------------------------
94
Post-Meeting on CoinTime leakage in 10.6GeV KaonLT data
95
- Dave, Richard, Alicia, Junaid, Nacer, Vijay, GH
96

    
97
Alicia shows plot of CT (range -30,30+log z) vs MM (pi+n PID)
98
- mmpi_10p6.pdf
99
- see a band with good pi+ MM over a wide range of CT
100
- the behavior is atypical, but could be due to poor CT timing resolution
101
  during 10.6GeV run, which was fortunately fixed before rest of KaonLT run
102
- Nacer confirmed at Regina group meeting that this behavior is absent in 3.8
103
  GeV data, no CT band at pi+n mass
104

    
105
- Dave: Why is the band not through whole region?
106
   - Should be at other MM peaks (ie K+lambda)
107
   - Is it just because pi+n is so large, and harder to see in lambda?
108
     - this is most likely the case, Alicia changes some cuts to select
109
       pi+Delta region and the problem seems to be there too, although more
110
       washed out in MM
111

    
112
- Dave: can have singles within cointime window and steal the good time
113
  (making it show up at bad time) although the tracking algorithm still picks
114
  up the correct MM
115
  - In general, this should have a very small probability, unless timing
116
    window cuts are wide open
117
    - need to treat CoinTime like any other detector and place time windows on
118
      both legs into CoinTime module
119

    
120
Richard confirms that Timing windows for KaonLT hallc_replay are set:
121
github.com/JeffersonLab/hallc_replay_lt/blob/LTSep_Analysis_2022/PARAM/
122
  TRIG/KaonLT/PARAM/tcoin.param
123
- *Alicia* will double check that this is set the same way in hallc_helicity
124
  analysis
125

    
126
*Richard* needs to add CT vs MM for lambda analysis (log scale CT, no CT cuts)
127
to confirm whether he sees the same behavior
128
- we have to deal with the issue either way, but how we approach it would be
129
  different, whether or not he sees it
130

    
131
Dave: Maybe non-Gaussian behavior caused by the reversed signal to CoinTime
132
module causes it to broaden in the CT spectrum so we're seeing long
133
non-Gaussian tails
134
- Dave suggests: Check Heep 10p6, since no randoms shouldn't be seen for clean
135
  elastics.  This would allow us to estimate the size of non-Gaussian tails
136

    
137
This suggests two possible ways to correct for the issue:
138
- Dave's way: use Heep CoinTime distribution to estimate size of Non-Gaussian
139
  CT tails
140
- Garth's way: subtract "far randoms" from "close randoms" in physics data to
141
  get size of Non-Gaussian tails
142
- best to check both methods.  If consistent within errors, then can apply
143
  easier-to-determine Heep correction to 10.6GeV KaonLT physics data
144

    
145
Richard finds a Heep-COIN 10p6 replay that we can look at
146
- CT looks very asymmetric even here, non-Gaussian tails -25 -> -5 and +5 ->
147
  +20 ns (plot posted on RedMine)
148
  - heep_coin_time_10p6.pdf
149
  - Cuts applied:
150
    tv__tree->Draw("CTime_epCoinTime_ROC1","abs(CTime_epCoinTime_ROC1)<50 &&
151
    abs(hsdelta)<8 && H_cer_npeSum>2 && ssdelta>-10 && ssdelta<20 &&
152
    P_aero_npeSum<2","", 86385, 0);
153

    
154
Dave: Beta cut may be hiding the issue, a comparison may be useful
155
- Plot of P_gtr_beta vs CoinTime for Heep-COIN replay
156
  - ctime_vs_beta.pdf
157
- beta has a bifurcation that occurs outside usual cut abs(beta)<0.3
158
  - Richard and Stephen saw this effect with beta much earlier, but didn't
159
    investigate further
160
- Alicia coinfirms that 10.6GeV physics data have the same issue
161
  - cointime_beta_10p6.pdf
162
  - *Alicia* will explore CT vs beta to see if cutting it makes much difference
163
  - seems likely that we should remove beta cut as it complicates the
164
    correction for non-Gaussian tails, particularly since beta provides limited
165
    PID information at high momentum
166

    
167
  - Alicia and Richard will ask Stephen about this, but this CT asymmetric
168
    peak generally might be a good thing to bring up for the next Quarterly
169
    Analysis meeting
170

    
171
Homework:
172
- Alicia: confirm that tcoin.param cuts are applied correctly
173
- Alicia: explore CT vs beta to see if cutting it makes much difference
174

    
175
- Richard: confirm that get same behavior of CT vs MM (although Heep-Coin seems
176
  already to show this)
177
- Richard: compute Non-Gaussian correction both ways, and we will have to
178
  decide which method is more reliable to apply to data
179

    
180
GH checks logbook, and thinks the CT timing error was fixed by Brad on
181
2018-Nov-15
182
- https://logbooks.jlab.org/entry/3626796
183
- https://logbooks.jlab.org/entry/3626194
184
- This is during the SIDIS-CSV run between the 10.6 and 3.8 GeV KaonLT data
185
  taking
186

    
187

    
188
Next Meeting
189
------------
190
- Tues Oct 10 @ 15:00 Eastern/13:00 Regina/12:00 Pacific
191
- PionLT will go first
192

    
193
Join Zoom Meeting
194
https://uregina-ca.zoom.us/j/94470211297?pwd=djBROEdWUENLUTF3ZFN1c0kvS0VIQT09
195

    
196
Meeting ID: 944 7021 1297
197
Passcode: 320362
(299-299/513)