Bose-Einstein study of position-momentum correlations of charged pions in hadronic Z0 decays

TL;DR

This study investigates Bose-Einstein correlations of charged pions in Z0 decays, revealing position-momentum correlations and source dynamics using high-statistics LEP data and advanced parameterizations.

Contribution

It is the first to analyze Bose-Einstein correlations assuming a non-static source in Z0 decays, providing insights into source geometry and velocity correlations.

Findings

Source dimensions decrease with higher pair transverse momentum

Source rapidity scales with pair rapidity

Longitudinal and transverse source sizes vary with momentum

Abstract

A study of Bose-Einstein correlations in pairs of identically charged pions produced in e+e- annihilations at the Z0 peak has been performed for the first time assuming a non-static emitting source. The results are based on the high statistics data obtained with the OPAL detector at LEP. The correlation functions have been analyzed in intervals of the average pair transverse momentum and of the pair rapidity, in order to study possible correlations between the pion production points and their momenta (position-momentum correlations). The Yano-Koonin and the Bertsch-Pratt parameterizations have been fitted to the measured correlation functions to estimate the geometrical parameters of the source as well as the velocity of the source elements with respect to the overall centre-of-mass frame. The source rapidity is found to scale approximately with the pair rapidity, and both the longitudinal and transverse source dimensions are found to decrease for increasing average pair transverse momenta.