Experimental Sensitivity to Solenoidal Field

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Revision as of 17:57, 27 April 2010 by Elton (Talk | contribs) (Figure-of-Merit)

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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 ~ 1/R_{{EM}}, where R_{{EM}} 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 / (R_{{EM}} x width)
  • For constant sensitivity, the experimental run time ~ R_{{EM}} x width = 1/FOM.
FOM ~ 1/(R_EM x omega width)