Difference between revisions of "Observables"
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[[Image:1.png|180px]] | [[Image:1.png|180px]] | ||
| − | A<sub>xx</sub> is an asymmetry so take advantage of numerator denominator systematics cancellation: | + | A<sub>xx</sub> is an asymmetry so take advantage of numerator denominator systematics cancellation:<br> |
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1.) Measure N<sub>p</sub> and N<sub>u</sub> with same cup same exact material <br> | 1.) Measure N<sub>p</sub> and N<sub>u</sub> with same cup same exact material <br> | ||
2.) Use same B-field <br> | 2.) Use same B-field <br> | ||
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6.) Switch from pol to unpol frequently <br> | 6.) Switch from pol to unpol frequently <br> | ||
| − | For unpolarized electron beam: | + | For unpolarized electron beam the helicity dependent cross sections are: <br> |
[[Image:2.png|180px]] | [[Image:2.png|180px]] | ||
| + | [[Image:3.png|150px]]<br> | ||
| + | Where in the deuteron rest frame the spin is quantized in the direction of the virtual photon<br> | ||
| − | + | This means there is a direct relationship to first component analyzing power<br> | |
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| − | [[Image: | + | [[Image:0.png|230px]] |
| − | which is very much accessible with e+D->e+N+X <br> | + | which is very much accessible with e+D->e+N+X and e+D->e+X (be weary of background) <br> |
| + | Modern (2006) Thesis [http://blast.lns.mit.edu/PUBLIC_RESULTS/THESES/Zhang_thesis.pdf] <br> | ||
| − | In addition we have a direct relationship to b1 for low x | + | In addition we have a direct relationship to b1 for low x (be weary uncertainties) <br> |
[[Image:5.png|200px]] | [[Image:5.png|200px]] | ||
Latest revision as of 14:15, 25 April 2013
A couple of words about Axx and how to measure it:
Axx is an asymmetry so take advantage of numerator denominator systematics cancellation:
1.) Measure Np and Nu with same cup same exact material
2.) Use same B-field
3.) Use NMR on both to measure polarization and un-polarization
4.) Let beam heating an off larmor microwave control un-polarization
5.) Keep both cold (~1K)
6.) Switch from pol to unpol frequently
For unpolarized electron beam the helicity dependent cross sections are:
Where in the deuteron rest frame the spin is quantized in the direction of the virtual photon
This means there is a direct relationship to first component analyzing power
which is very much accessible with e+D->e+N+X and e+D->e+X (be weary of background)
Modern (2006) Thesis [1]
In addition we have a direct relationship to b1 for low x (be weary uncertainties)
