Interconnection phenomena in W pair production at DELPHI

Interactions between the products of the hadronic decays of different Ws in WW pair events can occur at several stages: from the colour rearrangement between the quarks coming from the primary branching, to the gluon exchange during the parton cascade, to the mixing of identical pions due to Bose-Einstein correlations. Besides the intrinsic interest of their study related to the understanding of the multiparticle production mechanisms, these phenomena can affect the ultimate accuracy in the W mass measurement by LEP 2. The status of the DELPHI experimental analysis on interconnection effects between W pairs hadronically decaying is reviewed in this paper. (3 refs).