Fermi-Dirac Correlations in Z^{0} \to ppX at LEP
  The DELPHI and ALEPH experiments have released new results of the Fermi-Dirac correlations for pp (\bar{p} \bar{p}) and Bose-Einstein correlations for K^0_s K^0_s. Both experiments measure very small source radius for protons R \sim 0.1 fm. The source dimension for K^0_s K^0_s is in agreement with the previous measurements for K^+ K^-, K^0_s K^0_s. These results, together with earlier LEP measurements, establish the dependence of the correlation radius on the hadron mass. This paper discusses some of the attempts to describe this phenomenon. 
M. Kucharczyk