Transverse-longitudinal HBT correlations in p over(p, ̄) collisions at sqrt(s) = 630 GeV
Correlations of like-sign pion pairs emerging from proton-antiproton collisions are analysed in the two-dimensional ( qL, qT ) decomposition of the three-momentum difference q. While the data cannot be adequately represented by Gaussian, exponential, power-law or Edgeworth parametrisations, more elaborate ones such as Lévy and an exponential with a cross term do better. A two-scale model using a hard cut to separate small and large scales may indicate a core that is more prolate than the halo. Consideration not only of the interference peak at small ( qL, qT ), but also of the shape of the correlation distribution at intermediate momentum differences is crucial to understanding the data. © 2006 Elsevier B.V. All rights reserved.