Two-particle angular correlations in e + e − collisions to hadronic final states in two reference coordinates at Belle

We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis. We propose the latter as a good representation for the correlation structure interpretation in the e + e − collision system. The e + e − collisions to hadronic final states at center-of-mass energies of √(s) = 10 . 52 GeV and 10.58 GeV are recorded by the Belle detector at KEKB. In this paper, results on the first dataset are supplementary to the previous Belle publication [ 1 ]. At the same time, the latter is the first two-particle correlation measurement at collision energy on the Υ (4 S ) resonance and is sensitive to its decay products. Measurements are reported as a function of the charged-particle multiplicity. Finally, a qualitative understanding of the correlation structure is discussed using a combination of Monte Carlo simulations and experimental data.