Project

General

Profile

Kaon LT Meetings » mtg_24apr25.txt

Garth Huber, 04/25/2024 06:50 PM

 
1
                Apr 25/24 PionLT/KaonLT Analysis Meeting Notes
2
                ----------------------------------------------
3
                                (Notes by GH)
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 - Garth Huber, Nacer Hamdi, Ali Usman, Alicia Postuma, Muhammad Junaid,
13
   Nathan Heinrich, Vijay Kumar
14
York - Stephen Kay
15
JLab - Dave Gaskell
16
CSULA - Konrad Aniol
17
CUA - Tanja Horn
18

    
19
Vijay Kumar
20
-----------
21
Initial results of Low Q2 PionLT L/T-separations
22
- changed formula for sigT to a+b*(-t) type form for now
23
- fits now converge, was able to do several iterations
24

    
25
- comparisons between Data and MC distributions look reasonably good
26
  - should change lower MM cut to ~0.91, or remove entirely, to avoid
27
    correction for events lost due to the cut
28

    
29
- Exp/MC ratios are approximately 1, but with some phi-dependence for some
30
  t-bins
31
  - GH and Vijay will need to look more closely at these, with the aim of
32
    making the ratios more flat vs phi
33
    - likely will have to modify the sigT equation to get a better fit, need a
34
      close look to see what to do
35
    - possibly the LT, TT equations will also need modification
36

    
37
- sig_UNS phi distributions looking better than before, the phi distribution is
38
  getting more consistent between low, mid, high-epsilon
39
  - these will hopefully improve further once the ratios are more flat vs phi
40

    
41
- initial L/T/LT/TT cross sections
42
  - sigLT has a trend to values closer to zero as -t decreases, but the
43
    smallest -t bin does not have the smallest magnitude, this will need
44
    investigating
45
  - the t-dependence of sigL also will need confirmation, likely it will change
46
    as the iterations continue
47

    
48
- showing results at weekly meetings  in order to gain feedback is important,
49
  we are willing to have Vijay go first for the next few meetings, if this is
50
  helpful to him
51

    
52
Ali
53
---
54
- recon_hcana was using wrong mass, gave weird phi-distributions
55
  - this has now been fixed
56
  - unfortunately, all SIMC needed to be re-run, as old files were deleted
57

    
58
Alicia
59
------
60
BSA systematic uncertainties
61
- A=full fit, A'=simple fit, typically A<A'
62
- quoting A as final value, with syst_fit=|A-A'|
63
- showing this as a +/-systematic over-estimates the uncertainty, as the real
64
  value presumably is between A and A'
65
- agreed that we will show syst_fit as an asymmetric error
66

    
67
- will not be present next week due to other obligation, hoping to give an
68
  update on the BSA paper in 2 weeks
69

    
70
Nacer
71
-----
72
KaonLT Low Q2 PID efficiency systematics checks
73
- recap of Ali's 2023 slides where HMS_cal and HMS_cer efficiencies were found
74
  using Heep runs
75
  - runs 6600, 6603 were from this data set
76
  - used only 2-4 GeV/c runs to avoid pi- Cherenkov radiation
77
  - for CAL_eff, placed tigher cuts on CER, and vice versa
78
  - small rate dep was seen in CER_eff, Ali took the average, and found a
79
    systematic from the RMS deviation
80

    
81
Nathan
82
------
83
PionLT BCM calib
84
- met w/Dave Mack this morning to discuss Nathan's initial results
85
  - DM thinks a combined fit using runs w/same config can eventually be used
86
  - suggested that Nathan look at BCM1,2 and throw away runs>50uA due to
87
    small non-linearity
88
  - will check how stable the parames are before doing a combined fit
89
- DaveM's main concern from Nathan's Lumi work so far is that the found 170nA
90
  offset is too large, was expecting an offset closer to 70nA based on prior
91
  experience
92
  - will recheck the offset after calibs complete
93
- Nathan will write a README on the changes to the calib code after complete
94

    
95
Junaid
96
------
97
- finding his experience @ JLab to be very valuable
98

    
99
Next Meeting
100
------------
101
- Thur May 2 @ 15:00 Eastern/13:00 Regina
102
  - PionLT will go first
103

    
104

    
105

    
106

    
(417-417/513)