From chi-squared to Bayesian model comparison and Levy expansions of Bose-Einstein correlations in e+e- reactions

TL;DR

This paper advances the analysis of Bose-Einstein correlations in e+e- reactions by integrating Bayesian model comparison with new Levy-based parametrisations, enhancing model discrimination over traditional chi-squared methods.

Contribution

It introduces Levy expansion parametrisations and applies Bayesian model comparison to better evaluate Bose-Einstein correlation models in e+e- data.

Findings

Bayesian approach provides increased discriminating power.

Levy-based parametrisations improve model fit evaluation.

Bayesian model comparison favors certain models over others.

Abstract

The usual chi-squared 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 L\'evy 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.