Numerical Computation of p-values with myFitter

Understand

Likelihood ratio tests are a widely used method in global analyses in particle physics.

• The computation of the statistical significance (p-value) of these tests is usually done with a simple formula that relies on Wilks' theorem.
• There are, however, many realistic situations where Wilks' theorem does not apply.
• In particular, no simple formula exists for the comparison of models that are not nested, in the sense that one model can be obtained from the other by fixing some of its parameters.