hello, John and fellow BLASTers:
here are my most recent d(e,e'p)n results:
1) deep_vector_asymmetry_vs_Q2_point_fits.ps
suspected errors in our mc have caused us not to entirely believe
vector polarizations gotten from fits to the mc. as such, we are
currently taking the vector polarization gotten from a fit of the
beam-vector asymmetry to the pure theory curves (i.e. no acceptance
taken into account) as our current "best" polarization value. the
data in this plot are subjected to a missing mass cut as well as a
thetaCMS cut (which is equivalent to a QE cut) and then fitted to
Arenhovel's QE deuterium analysis as well as Hoelher's hydrogen
analysis (since, QE d(e,e'p) with a spectator neutron essentially
reduces to elastic p(e,e'p)). both fits in both sectors agree very
nicely. the agreed upon dilution (i.e. h * Pz) is around 0.52 +-
0.02. assuming ahelicity value of 0.626 +- 0.016, this gives a
vector polarization since the June shutdown of about (83 +- 3)%.
2) deep_vector_asymmetry_vs_pm.ps
that being said, the mc is still basically correct. as such, here is
a plot of the beam-vector asymmetry versus missing momentum (i.e. the
unmeasured neutron's momentum) along with the mc's beam-vector
asymmetry assuming the derived dilution. the fit is, overall, pretty
good. some discrepancies exist at high pM and one point in the left
sector at pM = 0.175. but overall, the rise at pM = 0.3GeV is clearly
visible as well as the nearly flat region at low pM.
3) deep_tensor_asymmetry_vs_thetacms.ps and
deep_tensor_asymmetry_vs_phicms.ps
now, switch to the tensor asymmetry. admittedly, i haven't been
spending as much time on this asymmetry as i have on the beam-vector
ones. however, the plots still aren't too bad. zilu's thesis
includes plots of this asymmetry vs. thetacms and phicms. thus, i do,
too. the mc plots here have assumed a tensor polarization of 59%, as
gotten from Chi. the thetacms plots clearly have the same form as the
mc ones; however, they seem to be systematically shifted a little
above the mc ones in the perpendicular region and shifted a little
below in the parallel one. i do not know why. possibly a mc error???
the phi plots do a little better job at replicating the mc asymmetry.
in particular, note the replication of the oscillatory nature of the
perpendicular-region phi asymmetry.
4) missing_mass.ps
i sent this one out already. i just think it's a pretty plot. note
that both peaks are at mM = 0.940 or so, right as they should be. all
of my asymmetry plots included a cut on this peak.
5) missing_momentum.ps, missing_momentum_zoomed_in.ps, and
missing_momentum_vs_empty_target.ps
i also already sent out the first two of these plots. they are pretty
self-explanatory. the plots have all been normalized per Coulomb.
the third plot puts the full target and empty target plots together.
anyway, send me any comments or questions.
aaron
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