Inter-W Bose-Einstein Correlations ... or Not?

TL;DR

This paper critically reviews the current evidence for Bose-Einstein correlations between pions from different W bosons at LEP II, discussing implications for W mass measurements and pion interferometry.

Contribution

It provides a comprehensive summary of the experimental status and theoretical implications of inter-W Bose-Einstein correlations in high energy physics.

Findings

Evidence for inter-W Bose-Einstein correlations remains inconclusive.

Presence of correlations could bias W mass measurements.

Absence would challenge conventional pion interferometry models.

Abstract

A critical summary is given of the present status of the study of Bose-Einstein Correlations in W-pair production at LEP II. In particular, the evidence is reviewed for or against the existence of Bose-Einstein correlations between pions originating both from a different of the two W's. If present, such an inter-W interference would not only form a potential bias in the determination of the W mass, but also would provide a laboratory to measure the space-time development of the overlap. If absent, this would drastically change the conventional (Hanbury Brown and Twiss) picture of pion interferometry in high energy physics.