Two-particle angular correlations in $e^{+}{e}^{-}$ collisions to hadronic final states in two reference coordinates at Belle

Abstract

We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis, and propose the latter to be a useful 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 $\sqrt{s}=10.52$ 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 arXiv:2201.01694 while the latter one is the first two-particle correlation measurement at a collision energy on the $\hat{I}\yen (4S)$ resonance and 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.

Submitted to JHEP. 32 pages, 14 figures