== Q&A from Preblessing Talk at Exotics Meeting on 04/16/09 ==

s10 - Q:How can you be sure that trigger efficiency is 100%?  
A: It isn't exactly for just the diphoton trigger, as seen on slide 65.  
However, we are taking the .OR. of four triggers as described in Section 2 of the note 
and the Ht cut pushes the average photon ET up
on the plateau where it is well within 1%, much smaller than the acceptance or
luminosity systematic. The photon ET distribution after all kinematic cuts is shown 
in the Appendix C of the note. Also see cdfnote 9533 on diphoton trigger
efficiency.

s11 - Q:How much does the acceptance depend on the luminosity profile?
A: Our analysis isn't affected by the instantaneou luminosity. See Appendix C
of the note.

s14 - Q:It seems odd that the background doubled even though you dropped
the data without the EM timing cleanup.  
A: The QCD background fluctuated a little, and the EWK had a bug where part of the sample was not
used in the previous round which now fixed. Also we had not included
the Z->nunu background. See Appendix B of the note for a full description of
the changes.

s14 - Q:The overall acceptance is 7.8%, but almost all of the points on
slide 64 are above that value.  
A: The plot doesn't reflect luminosity weighting of the run periods.  
Later periods have many more events in them.

s14 - Q:Why doesn't more luminosity result in a better expected limit?
A: The acceptance went down because it inadvertantly was overestimated since
it didn't include the vertex swapping cut, that has been fixed in new result.  
Also, backgrounds are slightly higher as noted above. See Appendix B of the
note for a full description of the changes.

s22 - Q:What are the low metsig events that are not modeled by MetModel? 
A: They was a mistake, fixed for the blessing. See figure 5 of the note.

s35 - Q:Is the optimization done one variable at a time holding the
other two fixed, or by scanning all three simultaneously?  
A: All three simultaneously, as described in section 6 of the cdf note.

s35 - Q:How much would the expected limit change if you still included
P0 data?  
A: It didn't contribute very much, analysis is simpler to
perform and explain without it. Ballpark 1/sqrt[lumi], adding 400/pb.

s38 - Q:There appear to be two "islands" of signal, around 4 and 12?
Are these events with particular kinematic configurations?  
A: We changed the metsig plot to have overflow bins at metsig=10.
As described in Section 4 in the note there are subset of events with low
metsig (<7) due to the fact that while the non-interacting particles are
highly energetic, they might not have small eta, or there are two (or more)
that point in opposite directions and cancel each other out, giving small Met.
The second region about 7, including the overflow fins at metsig=10, is due to
event with large Met. Any detail above 7 is significantly affected by the
estimation techniques in the Met Model and should not be taken to seriously.
This is why we make the overflow at 10.
See entry 04/29/09 at http://hepr8.physics.tamu.edu/elee/ggMet.html for the
study in more details. 

s38 - Q:Are you sure there are enough statistics in your background
samples to be able to find the right optimal cut?  
A: We use what we
have, effect will be reflected in the limits since MC statistics are
included. Smooth distributions in limit expectations and large errors cover
and QCD isn't dominant background.