Difference between revisions of "Experimental Sensitivity to Solenoidal Field"
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= Figure-of-Merit = | = Figure-of-Merit = | ||
| − | We construct a Figure-of-Merit (FOM) based on the [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1471 calculated electromagnetic background rates] in the detector and [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid= | + | We construct a Figure-of-Merit (FOM) based on the [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1471 calculated electromagnetic background rates] in the detector and the [http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1469 resolution for reconstructing omega mesons]. The validity for this FOM is based on the following argument: |
| + | * Statistical sensitivity ~ signal/sqrt(background) | ||
| + | * signal ~ time x luminosity | ||
| + | * background ~ time x luminosity x width of signal peak | ||
| + | |||
| + | In addition, we assume that the luminosity is limited by the rates in the detectors which is dominated by electromagnetic background. Therefore | ||
| + | * luminosity ~ <math>1/R_{EM}</math>, where <math>R_{EM}</math> is the rate in one of the inner detectors, either the start counter or the FDC. (We use the start counter rate) | ||
| + | |||
| + | Therefore, | ||
| + | * Sensitivity ~ time x luminosity / sqrt (time x luminosity x width) ~ sqrt (time x luminosity / width) ~ sqrt (time / (<math> R_{EM}</math> x width) | ||
| + | * For constant sensitivity the time ~ <math> R_{EM} </math> x width = 1/FOM. | ||
Revision as of 17:44, 27 April 2010
References
- GlueX-doc-1471 Electromagnetic Background Rate Studies (for different solenoid magnet fields and FDC hole sizes)
- GlueX-doc-1425 Magnetic Field Studies Status
- GlueX-doc-1469 Studies of particle reconstruction for $\omega$ and X(2000) events
Figure-of-Merit
We construct a Figure-of-Merit (FOM) based on the calculated electromagnetic background rates in the detector and the resolution for reconstructing omega mesons. The validity for this FOM is based on the following argument:
- Statistical sensitivity ~ signal/sqrt(background)
- signal ~ time x luminosity
- background ~ time x luminosity x width of signal peak
In addition, we assume that the luminosity is limited by the rates in the detectors which is dominated by electromagnetic background. Therefore
- luminosity ~
, where 
is the rate in one of the inner detectors, either the start counter or the FDC. (We use the start counter rate)
Therefore,
- Sensitivity ~ time x luminosity / sqrt (time x luminosity x width) ~ sqrt (time x luminosity / width) ~ sqrt (time / ( x width)
- For constant sensitivity the time ~ x width = 1/FOM.
