https://doi.org/10.1140/epjc/s10052-021-09777-3
Regular Article - Theoretical Physics
Z lepton flavour violation as a probe for new physics at future 
colliders
1
School of Physics, Nankai University, 300071, Tianjin, China
2
Physik-Department, Technische Universität München, James-Franck-Straße, 85748, Garching, Germany
3
Center for High Energy Physics, Indian Institute of Science, 560012, Bangalore, India
Received:
29
July
2021
Accepted:
27
October
2021
Published online:
1
December
2021
In this work we assess the potential of discovering new physics by searching for lepton-flavour-violating (LFV) decays of the Z boson, 
, at the proposed circular colliders CEPC and FCC-ee. Both projects plan to run at the Z-pole as a “Tera Z factory”, i.e., collecting 
Z decays. In order to discuss the discovery potential in a model-independent way, we revisit the LFV Z decays in the context of the Standard Model effective field theory and study the indirect constraints from LFV 
and 
decays on the operators that can induce . We find that, while the 
rates are beyond the expected sensitivities, a Tera Z factory is promising for 
decays, probing New Physics at the same level of future low-energy LFV observables.
© The Author(s) 2021
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Funded by SCOAP3
