Long-range near-side correlation in e+e- Collisions at 183-209 GeV with ALEPH Archived Data

The first measurement of two-particle angular correlations for charged particles produced in e+e- annihilation up to sqrt{s} = 209 GeV with LEP-II data is presented. Hadronic e+e- data, archived at center-of-mass energies ranging from 183 to 209 GeV, were collected using the ALEPH detector at LEP. The angular correlation functions have been measured across a wide range of pseudorapidities and the full azimuth in bins of charged particle multiplicity. This is the first such measurement using LEP-II data.

Results for e+e- data at high energies, which allows for higher event multiplicities than LEP-I at Z pole energy and has multiplicities reach beyond 50, are presented for the first time. A long-range near-side excess in the correlation function has been identified in the analysis when calculating

particle kinematic variables with respect to the thrust axis. Moreover, the two-particle correlation functions were decomposed using a Fourier series, and the resulting Fourier coefficients v_n were compared with event generator outputs. In events with high multiplicity featuring more than 50 particles, the extracted v_2 magnitude from the data are compared to those from the Monte Carlo reference.