Estimating the parameters of Bose–Einstein correlations from the two-particle correlation function in multihadronic final states

To estimate the strength of the Bose–Einstein correlations and the radius of the hadronization region in multiparticle production, the two-particle correlation functions R for identical pairs is adjusted to a parametric function describing the enhancement at small momentum differences. This is usually done by means of a binned uncorrelated least-squares fit. This article demonstrates that this procedure underestimates the statistical errors. A recipe is given to construct from the data the covariance matrix between the bins of the histogram of the two-particle correlation function.