Very interesting. How much data (kCoulombs) are in the analaysis?
Richard
On Thu, 8 Apr 2004, vitaliy ziskin wrote:
> Here is the plot that I should have included in my talk at the analysis
> meeting. I was playing with extracting neutron asymmetry by simply
> selecting a quisi-elastic kinamatics, determined by purely electron side
> and selecting neutron in a final state (trig 2). This of course is very
> coarse since there is no information about neutron momentum.
> Effectively I select all quesi-elastic neutrons regardless to the final
> state kinematics. The effect of that is "washing" out the asymmetry
> since it is in fact a function of a final state kinematics. However, as
> it turned out there is some asymmetry that remained. I did the same to
> the blastmc predictions for GeN=Galster (gray filled area) and GeN=0.0
> (red filled area) in order to be compare apples to apples. Blastmc
> asymmetry was then multiplied by extracted beam-target asymmetry from
> proton channel (dil. ~ 0.5 on both side), which still needs to be studied.
>
> Few comments:
> 1) The quesi-elastic peak is clearly visisble for low Q^2 (Q^2 < 0.35
> GeV/c^2) . It is broadened by motion of neutrons and resolution.
> 2) Looking at the raw data Mike and I clearly saw contamination from
> neutral gammas. It is unclear as to what extent these gammas contribute
> to a quasi-elastic peak.
> 3) Background has not been accounted for here. This is something that I
> need to do next.
> 4) Left and right asymmetries are same as in proton plots.
> 5) Only left asymmetry is sensative to GeN. Right asymmetry is mostly
> due to kinamtic factors.
> 6) Longer blastmc is needed to reduce gray/red areas
>
> Cheer, Vitaliy
>
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