# From chi^2 to Bayesian model comparison : the example of Levy-based fits to e+e- correlations

CITATION: De Kock, M. B., Eggers, H. C. & Csorgo, T. 2012. From chi^2 to Bayesian model comparison : the example of Levy-based fits to e+e- correlations. In The Seventh Workshop on Particle Correlations and Femtoscopy, September 20th to 24th, 2011 The University of Tokyo, Japan.

The original publication is available at https://pos.sissa.it/154

Conference Paper

The usual χ2 method of fit quality assessment is a special case of the more general method of Bayesian model comparison which involves integrals of the likelihood and prior over all possible values of all parameters. We introduce new parametrisations based on systematic expansions around the stretched exponential or Fourier-transformed Lévy source distribution, and utilise the increased discriminating power of the Bayesian approach to evaluate the relative probability of these models to be true representations of a recently measured Bose-Einstein correlation data in e +e− annihilations at LEP.