Project

General

Profile

Kaon LT Meetings » mtg_24apr04.txt

Garth Huber, 04/04/2024 04:56 PM

 
1
                 Apr 4/24 PionLT/KaonLT Analysis Meeting Notes
2
                 ---------------------------------------------
3
                                (Notes by GH)
4

    
5
                     Today: PionLT 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 - Garth Huber, Nathan Heinrich, Nacer Hamdi, Ali Usman, Alicia Postuma,
13
   Muhammad Junaid, Vijay Kumar
14
FIU - Pete Markowitz
15

    
16
Nathan
17
------
18
PionLT Lumi update
19
- still waiting on Dave Mack re BCM calib, will prompt him tomorrow
20
- have calibs that are valid for 2 lumi scans @ 9.2 GeV, show first results
21

    
22
9.2 GeV Carbon Scan #1
23
- sees a small trend in HMS TrkEff over 0-15 kHz range, 99.8-99.75%
24
- SHMS TrkEff shows similar trend, but up to 200 kHz
25
- sees a 5% drop in RelYield at low beam current, corresponding to a 5%
26
  over-estimate of beam current at 3uA, a 0.15uA offset
27
9.2 GeV Scan #2
28
- similar trends seen
29

    
30
Some questions about corrections to the beam current in the scripts
31
- first there is an unusual logarithmic correction to the beam current
32
  attributed to Peter Bosted
33
- after this, a second correction is applied
34
- both are applied to the values used in Nathan's analysis
35
- more investigation is needed to understand these
36
- would like to discuss them with Richard
37
- it would be helpful also if Vijay could check what's in his code
38

    
39
Junaid
40
------
41
PionLT Heep Coin settings
42
- list of cuts shown for both data and SIMC
43
- data are normalized for Q and TrkEff
44
  - DetEff and EDTM are not yet applied
45
  - BCM calibs not yet correct
46

    
47
- Data MC comparos shown for a variety of variables for all 9 Heep settings
48
  - overall the shapes agree nicely
49
  - rebinned plots for Heep offsets
50
  - PMY will be used to determine OOP offsets
51

    
52
  - Ali: notices that PMZ, EM resolution is much worse than predicted by SIMC
53
    - could be due to a BPM calib error
54
    - will discuss this further with Junaid
55

    
56
Ali
57
---
58
piDelta BSA study
59
- results shown for Q2=3.0, W=3.14 high statistics setting
60
  - 2 t-bins, 8 phi-bins
61
  - bins with very low statistics or Delta fit fails are excluded
62

    
63
- Procedure used for MM fit:
64
  1) fit pi+n MC by matching integrals over 0.92-0.96
65
  - MC is narrower than data, so matching integrals results in the peak being
66
    too high, which is offset by being below data in the width
67
  2) fit SIDIS MC in region with minimal Delta contrib, 1.4-1.5
68
  - for bins where the data don't extend all the way to 1.5, the fit region is
69
    slid slightly lower, keeping the fit region width the same
70
  3) then fit piDelta MC to Bkd subtracted data
71
  4) sum of MC is formed after all fitting
72

    
73
- Result of fit shown for low -t, all phi bins, L,C,R SHMS
74
  - this is first time fits are shown with longer SIMC data runs
75
  - resulting MC distributions are smoother, resulting in better fit overall
76
  - MC consistently under-predicts 1.0-1.06 MM region
77
    - possibly the SHMS collimator scattering that GH is implementing will help
78
      fill in this region
79
  - there is a slight over-prediction of data around 1.1 in -90 to -45 phi bin,
80
    can be included in systematic
81
  - Right SHMS: 4 phi bins
82
    Left SHMS: only 2 phi bins, 2 bins removed due to failed fits, will show GH
83
    later
84
  - BSA shown vs phi, weighted average of L,R,C
85
    - BSA calculated by integrating Delta MM from 1.12-1.4 GeV
86
      - will do a MM cut dependence study later
87
    - resulting asymmetry is very nicely sinusoidal
88

    
89
Vijay
90
-----
91
Low Q2 pi+ LTsep iterations
92
- getting some weird results fitting interference terms
93
  - new params from fitting process not behaving as expected
94
  - going through code again to see if there is a bug
95
  - if checks don't find anything, will try setting LT,TT to zero and try
96
    improving from there
97

    
98
Alicia
99
------
100
pi+n BSA error analysis Part 2
101
- first show of Q2=3, W=2.32 results
102
  - BSA are similar to before delta-correction
103
  - t=0.25-0.30 still has a wonky phi distribution
104

    
105
- Q2=2.1, W=2.95
106
  - first bin (-t=0.01-0.04) full fit is over-fitting, but still gives results
107
    consistent with other bins
108

    
109
- Some small changes to Systematics Calc from Tuesday's discussion
110
  - will not include (A-A') simple vs full fit comparison in RMS of
111
    cut-dependence study
112
  - (A-A') is much larger than the others, so lumping it into RMS calculation
113
    would result in under-estimate of uncertainties
114
  - delta(CUTS)=RMS[ (A-CN), (A-CW), (A-MN), (A-MW) ]
115
  - shows table of errors for each point at one Q2, STAT, CUTS, BPOL, FIT
116
  - then takes SYST as sum of CUTS, BPOL, FIT in quadrature
117
  - shows LT' results vs -t for each setting, with double error bars
118

    
119
  - we should be able to finalize the selection of CLAS data to compare to ours
120
    for Q2-scan at fixed X_B soon
121

    
122
Nacer
123
-----
124
Low Q2 KaonLT RFtime correction
125
- plot of P.gtr.th vs RFtime shows correlation, data is for 4-5 runs
126
- fits a straight line: 0.64-3.05*xptar
127
- applies this as an adhoc correction, RFcorrected
128

    
129
- plot of MM vs RFcorrected shows even better separation between K+L, K+S and
130
  piDelta than before
131
  - width of piDelta band is narrower than before
132
  - will redo cut study using RFcorrected
133

    
134
  - can clearly see some K+L events wrapped around the bottom of plot
135
    - could not see these before due to wider pion background
136
    - will need to place a lower limit on pion cut at ~0.1 to keep them
137
    - alternately, can adjust RF offset by ~0.5ns to better center the K+L
138
      events in the RF window
139

    
140
Next Meeting
141
------------
142
- Thur April 11 @ 15:00 Eastern/13:00 Regina
143
  - KaonLT will go first
(407-407/470)