# Difference: SeparationpowerExampleplot (1 vs. 2)

Revision 2
19 Jul 2006 - Main.KlausFoehl
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 META TOPICPARENT name="PidtagMeeting02"

## Example Plot for Separation Power

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-- KlausFoehl - 26 Jun 2006
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## From Sigma to Efficiencies

• curves: The separation of two distributions does not yet specify the acceptance and rejection efficiencies. The graph (horizontal axis background particle 0, vertical axis particle 1) above shows probability lines for hypothesis (particle identified as) 0 and 1 (0.3 i.e. 70% 0 and 30% 1) for Gaussian distributions separated by 0,1,2,3,4 sigma (black lines). For non-gaussian behaviour see coloured lines examples.

• 2gauss with red line: It is only the next step that the choice of a separation criterion (red line) determines the efficiencies.
• curves with red dot: This corresponds to selecting a point (red blob, happens to be on the 2sigma line) in parameter space. Here only 60% of particles 1 are correctly identified, as only 4% of particles 0 are false positives.

-- KlausFoehl - 19 Junl 2006

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