Summary

• CLs is an approximately frequentist construction with useful properties for hypothesis testing in searches for new physics

  • Allows robust optimization
  • Behaves ~intuitively (~P(theory|data)) with addition of new, weak channel, increased background, increased uncertainties
  • Although it is ~P(data|theory) it behaves more like P(theory|data) than FC
  • Does not produce confidence intervals in the signal parameters.
  • Has ~correct false exclusion rate in region of full sensitivity and gives no exclusion below sensitivity bound.

• The same rich framework provides information relevant to the subjective decision to claim a discovery including a test of goodness-of-fit.