A study of K0SK0S Bose-Einstein correlations in hadronic Z0 decays

Abstract Bose-Einstein correlationsin K 0 S K 0 S pairs have been studied for the first time in e + e − annihilations. These correlations were measured through the quantity Q , the four momentumdifference of the pair. Out of about half a million Z 0 hadronic decay events a total of about 6000 events with two or more identified K 0 S mesons were used for the analysis We observe a threshold enhancement in K 0 S K 0 S pairs originating from a mixed sample of K 0 K 0 and K 0 K 0 ( K 0 K 0 ) pairs. Although we can not presently exclude that a part of this effect is due to scalar mesondecays, our analysis attributes the enhancement to Bose-Einstein correlations. We find the values for the strength of the effect and the radius of the K 0 S emitting source to be λ = 1.12 ± 0.33 ± 0.29 and R 0 = (0.72 ± 0.17 ± 0.19) fm, respectively, where the first error is statistical and the second systematic.