Transverse-longitudinal HBT correlations in proton-antiproton collisions at root(s) = 630 GeV

TL;DR

This study analyzes pion pair correlations in proton-antiproton collisions at 630 GeV, revealing complex structures that challenge simple models and suggesting a prolate core-halo geometry.

Contribution

It introduces a detailed two-dimensional correlation analysis and explores advanced parametrizations, highlighting the importance of multi-scale modeling in understanding particle emission sources.

Findings

Gaussian and simple models are inadequate for data

Levy and exponential with cross term models perform better

Evidence suggests a prolate core-halo structure

Abstract

Correlations of like-sign pion pairs emerging from proton-antiproton collisions are analysed in the two-dimensional (q_L,q_T) 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 Levy 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 (q_L,q_T), but also of the shape of the correlation distribution at intermediate momentum differences is crucial to understanding the data.