Bose-Einstein Correlations in ep Collisions at HERA using the H1 Detector

Abstract

The two-particle correlation function is measured for neutral current DIS events with 5< Q2 < 100 GeV2 with data taken by the H1 detector at HERA with -vFs = 300 GeV during the 1994 run period corresponding to an integrated luminosity of 1.3 pb-1. The diffractive and non-diffractive selections of the data are analysed separately, and both exhibit an enhanced correlation for small 4-momentum difference for like-sign pairs as expected from Bose-Einstein interference in the production amplitudes for identical boson pairs. Fits using a Gaussian parametrisation of the enhancement yield no statistically significant difference between the diffractive and non-diffractive samples. The non-diffractive data sample is further separately analysed in three bins of each of the kinematic variables x, Q2, and W as well as mean particle density, (dn/dry*), in the hadronic centre of mass frame. Of these a strong evolution of the Gaussian fit parameters is observed with increasing particle density only. The non-diffractive data are also compared to three fit parameterisations: Gaussian, exponential, and power-law. The most favourable X2 is obtained for the exponential fit, though the power-law attains a similarly successful description of the data in the region of low 4-momentum difference