Feb 20/25 PionLT/KaonLT Analysis Meeting Notes
                 ----------------------------------------------
                                (Notes by GH)

                     Today: PionLT will be discussed first

Present
-------
Regina - Garth Huber, Alicia Postuma, Muhammad Junaid, Nathan Heinrich,
   Vijay Kumar
CUA - Tanja Horn
JLab - Dave Gaskell
Virginia - Richard Trotta
FIU - Pete Markowitz
Ohio - Julie Roche

Junaid
------
Implications of updated HMS optics matrix elements
- reply received from Mark re. optics offsets
  - for P<5.5 GeV/c, use phi_offset=0 for HMS, phi_offset=-8.6E-10 for SHMS
    - Dave: the SHMS offset is so small that you can simply use zero for it

- GH reran the global Heep in-plane offset analysis for 9 settings
  - beam energy offsets are a bit smaller than before (with old ME), momentum
    and angle offsets are similar
  - comparo Data to SIMC Heep distributions:
    - W distributions look good
    - various discrepancies between EM and PM components
    - highest beam energy (10.55 GeV) is worse than the others
  - we also note that the beam energy offset at 10.55 GeV has a strange value
    compared to the others, the other 8 are all negative >-0.4, while the
    highest energy setting is positive +0.4 (the max value allowed by the arc
    energy measurement uncertainty)
  - this setting has P_HMS=5.878 GeV/c
  - Dave: the optics angle offsets for this momentum have been fit, but not yet
    delta, there might be a residual saturation effect causing the different
    behavior compared to the others
    - suggests that GH try fitting offsets where the angle offsets are the same
      as the other 8, but P_HMS offset is allowed to vary separately by a
      larger amount
    - Tanja and Julie confirm that the delta offsets are in progress, hopefully
      will be done "soon"

Next steps:
- Heep Data/MC yield ratios

Nathan
------
Gave some feedback following his talk at WNPPC
- people were intrigued by the Proton Spin Crisis, but were not familiar with
  it
  - this was mentioned as part of the motivation for GPDs and studying the
    applicability of hard-soft factorization
- we need to be more proactive in motivating our work to a broad audience

Richard
-------
Continued work on KaonLT L/T-separation
- changed Wfac to 1/(W^2-M^2)**(polynomial) where W_cent is used instead of W
  varying for every bin
  - this made things easier, particularly the W distributions (not shown)

- initial results shown for Q2=4.4, 5.5 with this parameterization
  - Q2=4.4, ratios now show a t-dependence
  - Q2=5.5, only t-bins, statistics are poor
  - sig_L,T,LT,TT trends vs -t are similar for both settings
    - results are very preliminary, magnitudes of cross sections don't make too
      much sense yet, negative sigT in some places
    - encouraged that same polynomial form can be used for both settings
  - Garth: in particular for Q2=5.5, where data are sparse, suggests to fix the
    non-dominant terms in the parameterization during iterations and only
    letting the most important terms float

Next steps:
- will try to have sig_L,T,LT,TT results for Q2=3.0, 4.4, 5.5 using same
  parameterization by next week

Vijay
-----
Q2=0.425 PionLT analysis
- shows diamond cut, looks good

- tried applying Q2=0.375 model in SIMC to Q2=0.425
  - getting negative weights, diagnosing problem
  - a bit of a surprise, since the kinematics of the two settings are so
    similar
  - Garth: maybe you have hard-coded some W_cent or Q2_cent in the code that
    needs to be updated for the new setting?

Next steps:
- after SIMC, will look at t-binning
  - as was mentioned last week, will try 7 bins instead of 8

Alicia
------
BSA paper modifications
- implemented changes per referee comments
- new title:
  Probing Hard-Soft Factorization via BSA in exclusive pi+ electroproduction
  from the proton
- revisions reviewed by GH, who suggested rearrangement of material in intro
  - the rearrangement is intended to more closely focus the intro to the new
    title

- proposed deadlines:
  - circulate draft by EoB Feb 21
  - comments due back no later than Mar 3
  - Tanja suggests to circulate not only to this group, but to all co-authors,
    since most comments will come from this group anyways
    - also suggests to include Alicia's document on the referee comments at the
      same time
    - 2 emails to go out:
      - all co-authors: PDF of paper and referee comments
      - this group: OverLeaf link
  - intending to submit to PLB by mid-March

Next Meeting
-------------
- Thur Feb 27 @ 15:30 Eastern/14:30 Regina
  - KaonLT will go first