Kaon interference in the hadronic decays of the Z⁰

Abstract

The first measurement of like-sign charged kaon correlations in hadronic decays of the Z⁰ is presented, based on data collected by the DELPHI detector. The charged kaons are identified by means of ring imaging Cherenkov detectors. A significant enhancement at small values of the four-momentum difference is observed in the ratio of like-sign to unlike-sign KK pairs and in the ratio of like-sign pairs to a simulated reference sample. An update of the measurement of K_s⁰K_s⁰ interference is also presented. An enhancement is found in the production of pairs of K_s⁰ of similar momenta, as compared with a simulated reference sample. The measured Bose-Einstein correlation parameters λ and r are similar for charged and neutral kaon pairs. The value of the Bose-Einstein correlation strength λ is consistent with unity.