Bose-Einstein Correlations in W+ W– events at LEP2

Abstract

Abstract.

Bose-Einstein correlations (BEC) between final state particles in the reaction \(\rm e^ + e^- \to W^ + W^- \to q_1\overline{q_2}q_3\overline{q_4}\) have been studied. Data corresponding to a total integrated luminosity of 550 pb^-1, recorded by the DELPHI detector at centre-of-mass energies ranging from 189 to 209 GeV, were analysed. An indication for inter-W BEC between like-sign particles has been found at the level of 2.4 standard deviations of the combined statistical and systematic uncertainties.