$\eta$ and ${\eta }^{\prime }$ decays into lepton pairs

Abstract

In this work, we calculate the branching ratios for the $\eta ({\eta }^{\prime })\to \bar{\ell }\ell$ decays, where $\ell =e,\mu$. These processes have tiny rates in the standard model due to spin flip, loop, and electromagnetic suppression, for what they could be sensitive to New Physics effects. In order to provide a reliable input for the Standard Model, we exploit the general analytical properties of the amplitude. For that purpose, we invoke the machinery of Canterbury approximants, which provides a systematic description of the underlying hadronic physics in a data-driven fashion. Given the current experimental discrepancies, we discuss in detail the role of the resonant region and comment on the reliability of $\chi$PT calculations. Finally, we discuss the kind of new physics which we think would be relevant to account for them.

35 pages, 18 figures. V2 matches the published version

References in corpus (14)

• Measurement of the rare decay pi0 -> e+ e-
• A Rational Approach to Resonance Saturation in large-Nc QCD
• The two-photon exchange contribution to muonic hydrogen from chiral perturbation theory
• Chiral dynamics predictions for eta' -> eta pi pi
• Rare decay ${\pi }^0\to e^{+}{e}^{-}$: on corrections beyond the leading order
• A rational approximation to <VV-AA> and its O(p^6) low-energy constant
• Large-Nc QCD and Pade Approximant Theory
• Pion transition form factor and distribution amplitudes in large-Nc Regge models
• Complete structure dependent analysis of the decay $P\to l^{+}{l}^{-}$
• Some Remarks on the Pade Unitarization of Low-Energy Amplitudes
• Search for the process $e^{+}{e}^{-}\to {\eta }^{\prime }(958)$ with the CMD-3 detector
• On mass corrections to the decays P \to l^+l^-
• On the two-photon contributions to $e^{+}{e}^{-}\to \eta \gamma$ and $e^{+}{e}^{-}\to {\eta }^{\prime }\gamma$
• Overview of the hadronic light-by-light contribution to the muon (g-2)

Cited by in corpus (23)

• Pseudoscalar-pole contribution to the $(g_{\mu }-2)$: a rational approach
• Precision tests of fundamental physics with $\eta$ and ${\eta }^{\prime }$ mesons
• Light Weakly Coupled Axial Forces: Models, Constraints, and Projections
• The ${\eta }^{\prime }$ transition form factor from space- and time-like experimental data
• Light Axial Vectors, Nuclear Transitions, and the ${}^8$Be Anomaly
• Measurement of the omega -> pi^0 e^+e^- and eta -> e^+e^-g Dalitz decays with the A2 setup at MAMI
• The interplay of transverse degrees of freedom and axial-vector mesons with short-distance constraints in g-2
• Signals of the QCD axion with mass of 17 MeV/c^2: nuclear transitions and light meson decays
• Probing lepton flavour (universality) violation at NA62 and future kaon experiments
• Measurement of the pi^0 -> e^+e^-gamma Dalitz decay at the Mainz Microtron
• Improved ${\pi }^0,\eta ,{\eta }^{\prime }$ transition form factors in resonance chiral theory and their $a_{\mu }^{\mathrm{HLbL}}$ contribution
• Improved Standard-Model prediction for ${\pi }^0\to e^{+}{e}^{-}$
• Dispersion relation for hadronic light-by-light scattering: $\eta$ and ${\eta }^{\prime }$ poles
• The contribution of pseudoscalar mesons to hyperfine structure of muonic hydrogen
• The radiative corrections to double-Dalitz decays revisited
• Radiative corrections to the ${\eta }^{(\prime )}$ Dalitz decays
• The semileptonic decays ${\eta }^{(\prime )}\to {\pi }^0{\ell }^{+}{\ell }^{-}$ and ${\eta }^{\prime }\to \eta {\ell }^{+}{\ell }^{-}$ in the standard model
• Probing the singularities of the Landau-gauge gluon and ghost propagators with rational approximants
• $CP$ violation in $\eta$ muonic decays
• Improved Standard-Model prediction for $K_L\to {\ell }^{+}{\ell }^{-}$
• Axial-vector exchange contribution to the Hyperfine Splitting
• Updated pseudoscalar contributions to the hadronic light-by-light of the muon (g-2)
• Neutral-pion decay into an electron-positron pair: A review and update