Bose-Einstein correlations in one and two dimensions in deep inelastic scattering

Bose-Einstein correlations in one and two dimensions have been studied in deep inelastic ep scattering events measured with the ZEUS detector at HERA using an integrated luminosity of 121 pb − 1 . The correlations are independent of the virtuality of the exchanged photon, Q 2 , in the range 0 . 1 < Q 2 < 8000 GeV 2 . There is no significant difference between the correlations in the current and target regions of the Breit frame for Q 2 > 100 GeV 2 . The two-dimensional shape of the particle-production source was investigated, and a significant difference between the transverse and the longitudinal dimensions of the source is observed. This difference also shows no Q 2 dependence. The results demonstrate that Bose-Einstein interference, and hence the size of the particle-production source, is insensitive to the hard subprocess.