[Sane-analysis] Reminder of Sane Meeting at 3:30pmToday Wed Oct 8th in f226

[O. A. Rondon]

Hi,

Here are the items we discussed at the meeting that I said I would look up:

- question of trend of d2 with E' or x.

I see a similar trend as Whit but for the SLAC data vs lower x limit
in the d2 integral, not for SANE. See plots on page 5 here (plots on P.
4 are the same, except they have a typo (fixed for those on p. 5,
changes things a bit)
https://userweb.jlab.org/~rondon/analysis/asym/world/A180_Aperp-q2-x_d2-xmin.pdf

The low x and min E' limits are related, but not identical.

For SANE d2 vs min E', I see the same trend we saw at the meeting, shown
above on p. 7, and with different g1 inputs on the top plot of page 5 (or 4)

- question of CLAS e+/e- fit

This is discussed in great detail in my wiki page
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Scaling_fits_to_Hall_C_positron_data

Summaries of e+/e- models that I've looked into (saves actually reading
the wiki page ;-) ), including the direct fits to Hall C pairs data for
5.9 GeV (top left), Hovhannes Wiser pi0 simulation (top right), and CLAS
(Vipuli) fit (bottom left), are here
https://userweb.jlab.org/~rondon/analysis/asym/pairs_models.pdf

The plain CLAS fit is the blue curve (pairs for just CLAS target). The
red curve is my expectation of what BigCal would see (includes tracker).

The Hall C fits for 4.7 GeV data are here
https://userweb.jlab.org/~rondon/analysis/asym/pairs_models_5_9-4_7.pdf

Finally, the fit by Vipuli in all detail is here
("Report on pair Background")
https://userweb.jlab.org/~rondon/sane/mtg7/index.html

and the code I used to get the SANE e+/- background from the CLAS fit (a
nontrivial job) is in this spreadsheet
https://userweb.jlab.org/~rondon/sane/analysis/pairs/pair_run_plan_short.ods

with this code I get f(E'=900 MeV)= 0.25 for CLAS only, and  f=0.62 for
SANE, without the tracker, 0.71 with the tracker.  I estimated the
tracker X0 using 9 mm of plastic.

Cheers,

Oscar