[Olympus] Talk on Monday

[Norair Akopov]

  Dear Michael,

I added the polar angles correlation cut and produced new plots, which are 
located again on:

http://www.desy.de/~akopov/Olympus_Monday_Meeting

you can compare the old plots with the momentum resolution at different 
\theta_e angular bins: electron(positron)_resol.pdf done W/O applied 
polar angles correlation cut with the new plots: 
electron(positron)_resol_new.pdf where this cut is applied. 
On the lower right panel (\theta_e&\theta_pr double plot) you can see that 
this wide background area seen on old plots is now almost removed.
The meaning of applied cut should be clear from the plots: 
electron(positron)_theta_q2.pdf,
where the comparison of \theta_e and \theta_pr distribution as well 
the Q2 dsitributions are plotted with and W/O this additional cut applied.
At any place I'm writing e.g  \theta_pr=f(E_0,\theta_e^{WC}) I mean that 
f() is just expression based on elastic kinematics conditions.

You can see that background clearly seen for angular distributions (at 
high angles for lepton and at low angles for proton) W/O 
this cut applied is essentially suppressed after the cut was applied.

Then I estimated the rate of expected selected (close to elastic) events 
sample with all cuts described in my talk W/O polar angle correlatrion cut 
and with. This is effi.pdf file, where you can see, that unfortunately 
with this additional cut the expected staistics at high 
\theta_e angles, where we should reach the smallnest values of \epsilon 
is essentially decreased..

I'm now thinking on another form to introduce the polar angles correlation 
cut to select the data. It seems the used ratio of 
sin(\theta_pr^{WC})/sin(\theta_pr=f((E_0,\theta_e^{WC}) to be close to 
unity within 3 \sigma is too strong.

Best regards,

Norik