Prospects for a flavour violating $$Z^\prime $$ explanation of $$\Delta a_{\mu ,e}$$

Autor: J. Kriewald, J. Orloff, E. Pinsard, A. M. Teixeira
Přispěvatelé: Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)
Rok vydání: 2022
Předmět:
Zdroj: Eur.Phys.J.C
Eur.Phys.J.C, 2022, 82 (9), pp.844. ⟨10.1140/epjc/s10052-022-10776-1⟩
ISSN: 1434-6052
DOI: 10.1140/epjc/s10052-022-10776-1
Popis: The apparent tensions emerging from the comparison of experimental data of the anomalous magnetic moments of the muon and electron to the Standard Model predictions ($\Delta a_{\mu,e}$) could be interpreted as a potential signal of New Physics. Models encompassing a light vector boson have been known to offer a satisfactory explanation to $\Delta a_{\mu}$, albeit subject to stringent experimental constraints. Here we explore a minimal extension of the Standard Model via a leptophilic vector boson $Z^\prime$, under the hypothesis of strictly flavour-violating couplings of the latter to leptons. The most constraining observables to this ad-hoc construction emerge from lepton flavour universality violation (in $Z$ and $\tau$ decays) and from rare charged lepton flavour violating transitions. Once these are accommodated, one can saturate the tensions in $\Delta a_{\mu}$, but $\Delta a_{e}$ is predicted to be Standard Model-like. We infer prospects for several observables, including leptonic $Z$ decays and several charged lepton flavour violating processes. We also discuss potential signatures of the considered $Z^\prime$ at a future muon collider, emphasising the role of the $\mu^+\mu^- \to\tau^+\tau^- $ forward-backward asymmetry as a key probe of the model.
Comment: 36 pages, 15 figures, v3: minor changes, few clarifications added, results and conclusions unchanged, matches version published in EPJC
Databáze: OpenAIRE
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