Search for new physics effects in $ν\barνγ$ production at a Tera-Z factory

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Denizli, H., Senol, A., Köksal, M.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910074630307840
author Denizli, H.
Senol, A.
Köksal, M.
author_facet Denizli, H.
Senol, A.
Köksal, M.
contents Rare decays of the Z boson provide a sensitive probe for physics beyond the Standard Model (SM). This study investigates the $e^{+}e^{-} \to Z \to ν\barνγ$ process within the context of the Tera-Z programmes at future colliders such as the FCC-ee and CEPC. The SM predicts a one-loop branching ratio of $7.16 \times 10^{-10}$ for $Z \to ν\barνγ$, a value four times smaller than the current experimental limit from the LEP. To explore this window for new physics, we parameterize anomalous $Zν\barνγ$ interactions using an Effective Field Theory framework, considering both dimension-6 and dimension-8 operators. A detailed simulation is performed by generating signal and background events with MadGraph, modeling particle showers with Pythia, and simulating detector effects with Delphes. The analysis employs key kinematic variables-including the photon energy ($E_γ$), missing transverse energy ($\not{E}_T$), and the missing transverse energy significance ($S_{\not{E}_T}$) to isolate the signal. The results yield upper limits on the anomalous couplings, from which we infer branching ratios for $Z \to ν\barνγ$ on the order of $10^{-9}$. This represents a significant improvement of several orders of magnitude over the LEP sensitivity. Consequently, this study demonstrates the unique potential of the Tera-Z runs not only to test the SM loop-level predictions with unprecedented precision but also to tightly constrain or reveal new anomalous interactions.
format Preprint
id arxiv_https___arxiv_org_abs_2510_23065
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Search for new physics effects in $ν\barνγ$ production at a Tera-Z factory
Denizli, H.
Senol, A.
Köksal, M.
High Energy Physics - Phenomenology
High Energy Physics - Experiment
Rare decays of the Z boson provide a sensitive probe for physics beyond the Standard Model (SM). This study investigates the $e^{+}e^{-} \to Z \to ν\barνγ$ process within the context of the Tera-Z programmes at future colliders such as the FCC-ee and CEPC. The SM predicts a one-loop branching ratio of $7.16 \times 10^{-10}$ for $Z \to ν\barνγ$, a value four times smaller than the current experimental limit from the LEP. To explore this window for new physics, we parameterize anomalous $Zν\barνγ$ interactions using an Effective Field Theory framework, considering both dimension-6 and dimension-8 operators. A detailed simulation is performed by generating signal and background events with MadGraph, modeling particle showers with Pythia, and simulating detector effects with Delphes. The analysis employs key kinematic variables-including the photon energy ($E_γ$), missing transverse energy ($\not{E}_T$), and the missing transverse energy significance ($S_{\not{E}_T}$) to isolate the signal. The results yield upper limits on the anomalous couplings, from which we infer branching ratios for $Z \to ν\barνγ$ on the order of $10^{-9}$. This represents a significant improvement of several orders of magnitude over the LEP sensitivity. Consequently, this study demonstrates the unique potential of the Tera-Z runs not only to test the SM loop-level predictions with unprecedented precision but also to tightly constrain or reveal new anomalous interactions.
title Search for new physics effects in $ν\barνγ$ production at a Tera-Z factory
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
url https://arxiv.org/abs/2510.23065