First measurement of the one-point charge correlator in e+e- collisions at √s = 91.2 GeV with DELPHI Open Data
Abstract
The chiral structure of the Z couplings imprints a parity-odd flow of electric charge on hadronic Z decays. The related forward-backward asymmetries, a key set of observables in the electroweak precision program, were measured at LEP and SLC using the jet charge. The one-point charge correlator offers a complementary route, measuring the hadronic charge flow directly as a function of polar angle relative to the incoming electron-beam axis, without reference to jets or a reconstructed quark direction, following the formalism developed in a companion paper. We report its first measurement, using 61 pb−1 of archival DELPHI Open Data recorded at √s = 91.2~GeV in 1994 and 1995. Detector effects are corrected in two stages. The first is derived from fully simulated samples, and the second bounds the residual charge-misreconstruction difference between data and simulation using a measurement in e+e-→τ+τ- events. The measured charge correlator exhibits the characteristic parity-odd sin(2θ) modulation and agrees with the \textsc{PYTHIA}~8.3 prediction. The measurement demonstrates that the parity-odd charge flow of hadronic Z decays is directly accessible in data, differentially in polar angle, and the paper discusses strategies for controlling the associated detector effects, paving the way for a new program of charge-flux measurements, both in archival e+e- data and at future colliders.
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BibTeX
@misc{zhang2026first,
title = {{First measurement of the one-point charge correlator in $e^+e^-$ collisions at $\sqrts = 91.2$ GeV with DELPHI Open Data}},
author = {Jingyu Zhang and Yi Chen and Kyle Lee and Ian Moult and Cristian Baldenegro and Hannah Bossi and Yen-Jie Lee},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.15357},
eprint = {2608.15357},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.15357},
}
RIS
TY - UNPB
TI - First measurement of the one-point charge correlator in e^+e^- collisions at √s = 91.2 GeV with DELPHI Open Data
AU - Jingyu Zhang
AU - Yi Chen
AU - Kyle Lee
AU - Ian Moult
AU - Cristian Baldenegro
AU - Hannah Bossi
AU - Yen-Jie Lee
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2608.15357
UR - https://arxiv.org/abs/2608.15357
AB - The chiral structure of the Z couplings imprints a parity-odd flow of electric charge on hadronic Z decays. The related forward-backward asymmetries, a key set of observables in the electroweak precision program, were measured at LEP and SLC using the jet charge. The one-point charge correlator offers a complementary route, measuring the hadronic charge flow directly as a function of polar angle relative to the incoming electron-beam axis, without reference to jets or a reconstructed quark direction, following the formalism developed in a companion paper. We report its first measurement, using 61 pb^−1 of archival DELPHI Open Data recorded at √s = 91.2~GeV in 1994 and 1995. Detector effects are corrected in two stages. The first is derived from fully simulated samples, and the second bounds the residual charge-misreconstruction difference between data and simulation using a measurement in e^+e^-→τ^+τ^- events. The measured charge correlator exhibits the characteristic parity-odd sin(2θ) modulation and agrees with the \textsc{PYTHIA}~8.3 prediction. The measurement demonstrates that the parity-odd charge flow of hadronic Z decays is directly accessible in data, differentially in polar angle, and the paper discusses strategies for controlling the associated detector effects, paving the way for a new program of charge-flux measurements, both in archival e^+e^- data and at future colliders.
ER -