Volume 390 - 40th International Conference on High Energy physics (ICHEP2020) - Parallel: Heavy Ions
Search for long range flow-like correlation in hadronic $e^{+}e^{-}$ collisions with Belle
Y.C. Chen,* C.W. Lin, Y.J. Lee, P. Chang
*corresponding author
Full text: Not available
Abstract
The enhancement of charged-particle pairs with large pseudorapidity difference and small azimuthal angle difference, often referred to as the "ridge signal", is a phenomenon widely observed in high multiplicity proton-proton, proton-ion and deutron-ion collisions, which is not yet fully understood. In heavy-ion collisions, the hydrodynamic expansion of the Quark-Gluon Plasma is the most popular explanation of the ridge signal. Measurements in the $e^+e^-$ collision system, without the complexities introduced by hadron structure in the initial state, can be a new opportunity to examine the formation of a ridge signal. The first measurement of two-particle angular correlation functions in high multiplicity $e^+e^-$ collisions at $\sqrt{s}=10.52$ GeV is reported. $31.5~{\rm fb}^{-1}$ hadronic $e^+e^-$ annihilation data collected by the Belle detector at KEKB are used in this study. Two-particle angular correlation functions are measured over the full azimuth and large pseudorapidity intervals which are defined by either the electron beam axis or the event thrust as a function of charged particle multiplicity. The measurement in the event thrust analysis, with mostly quark and anti-quark pairs determining the reference axis, is sensitive to soft gluon emissions associated with the outgoing (anti-)quarks. No significant ridge signal is observed with analyses performed in either coordinate system. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various $e^+e^-$ event generators and expected to provide new constraints to the phenomenological models in the low collision energy regime.
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access