[Frost] meeting

[Brian Vernarsky]

In the meeting this morning I showed several plots of the components
of momentum (px, py and pz) in butanol vs CH2, and it was pointed out
that they did not make sense as they could not add to the total
momentum.  I promised to check it out.  I am not sure where the values
I got last time came from, but they make much more sense now, so
please see the attached pdfs to see the differences.  Now the two
targets have approximately the same width and shapes for all
components, there is just a subtle shift visible in the transverse and
z components of momentum.  BTW I included a fourth column to show the
transverse momentum, so now the columns are px, py, sqrt(px*px +
py*py), pz, the rows are proton, pip and pim, and black is butanol and
blue is ch2, as before.  This is good, at least now we know it is just
a subtle shift in both the transverse and longitudinal directions
which can hopefully be fixed by addressing the holding magnet.

I have also inplemented the change in Eloss Michael and I discussed
fixing the carbon and ch2 corrections for events that have very low z
momentum.  This does completely get rid of the dip that was seen near
pi/2 in the lab angle phi plots, which are included here.  Glad to see
we could fix something!

I will update the presentation I showed this morning with the new
plots and it will be available in about 20 minutes at:

http://www.andrew.cmu.edu/user/bvernars/FROST_update_2010-10-22.pdf

Let me know if there are any questions.

Brian
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