[Sane-analysis] SANE Analysis Meeting June 8, 2011

[O. A. Rondon]

Hi,

I have calculated the statistics weighted mean Q^2 for the 3 GeV^2 Q^2
band using James' tables of asymmetries.
http://www.jlab.org/~jmaxwell/asym/a1a2/w_bins_asym_table.txt
http://www.jlab.org/~jmaxwell/asym/a1a2/x_bins_asym_table.txt

I calculated it from the mean E' and mean theta for the bins, using the
appropriate beam energy, and from the mean x and mean W (mean =
statistics weighted kinematics).
http://www.jlab.org/~rondon/sane/analysis/asym/Q2/q2-W_x.pdf

The posted plots show that the mean Q^2 is not as constant as we may
like it to be, specially for computing moments. The problem may be with
the way the mean kinematics are being calculated now, or we may need to
modify the binning or the way the kinematic cuts are applied, so the
mean Q^2 is more constant.

The divergence at mid-x between the two forms of computing Q^2 may
be pointing to the former. The latter may involve adjusting the low E' >
1.3 GeV cut somewhat, to accept or reject more or fewer low Q^2 events,
depending on theta, and to perhaps restrict the minimum theta for some
bins, so more events with higher Q^2 are included.

If the calculation of the means is right, I encourage the analysis group
to think of clever ways of flattening the Q^2 distributions. A start
would be to make 2D plots of Q^2 vs W and x of the events that are now
in each band, and of the correlated E' and theta, etc.

Cheers,

Oscar