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Article
Report number	arXiv:2404.15937 ; KCL-PH-TH/2024-18 ; CERN-TH-2024-046
Title	Probing Neutral Triple Gauge Couplings via $\boldsymbol{Z\gamma\,(\ell^+\ell^-\gamma)}$ Production at $\boldsymbol{e^+e^-}$ Colliders
Author(s)	Liu, Danning (Shanghai Jiao Tong U.) ; Xiao, Rui-Qing (Shanghai Jiao Tong U. ; King's Coll. London) ; Li, Shu (Shanghai Jiao Tong U. ; Peking U., CHEP) ; Ellis, John (Shanghai Jiao Tong U. ; King's Coll. London ; CERN) ; He, Hong-Jian (Shanghai Jiao Tong U. ; Peking U., CHEP) ; Yuan, Rui (Shanghai Jiao Tong U.)
Publication	2025
Imprint	2024-04-24
Number of pages	14
Note	Frontiers of Physics (in Press), 22 pages, 10 Figs and 10 Tables
In:	Front. Phys. (Beijing) 20 (2025) 15201
DOI	10.15302/frontphys.2025.015201 (publication)
Subject category	hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology
Abstract	Neutral triple gauge couplings (nTGCs) are absent in the Standard Model (SM) and at the dimension-6 level in the Standard Model Effective Field Theory (SMEFT), arising first from dimension-8 operators. As such, they provide a unique window for probing new physics beyond the SM. These dimension-8 operators can be mapped to nTGC form factors whose structure is consistent with the spontaneously-broken electroweak gauge symmetry of the SM. In this work, we study the probes of nTGCs in the reaction $e^+e^-\to Z\gamma$ with $Z\to\ell^+\ell^-\,(\ell =e,\mu)$ at an $e^+e^-$ collider. We perform a detector-level simulation and analysis of this reaction at the Circular Electron Positron Collider (CEPC) with collision energy $\sqrt{s} = 240$ GeV and an integrated luminosity of 20 ab$^{-1}$. We present the sensitivity limits on probing the new physics scales of dimension-8 nTGC operators via measurements of the corresponding nTGC form factors.
Copyright/License	publication: © 2024 Higher Education Press preprint: (License: CC BY 4.0)

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