Updated SM predictions yield Br(η→e⁺e⁻)=5.37(4)(2)[4]×10⁻⁹, Br(η→μ⁺μ⁻)=4.54(4)(2)[4]×10⁻⁶, Br(η'→e⁺e⁻)=1.80(2)(3)[3]×10⁻¹⁰, and Br(η'→μ⁺μ⁻)=1.22(2)(2)[3]×10⁻⁷, with a mild 1.6σ tension in the η→μ⁺μ⁻ channel.
Measurements of the Meson-Photon Transition Form Factors of Light Pseudoscalar Mesons at Large Momentum Transfer
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
Using the CLEO~II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons $\pi^0$, $\eta$, and $\eta^{\prime}$. From our measurements we have obtained the form factors associated with the electromagnetic transitions $\gamma^*\gamma$ $\to$ meson. We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and 30 GeV$^2$ for $\pi^0$, $\eta$, and $\eta^{\prime}$, respectively, and have made comparisons to various theoretical predictions.
citation-role summary
citation-polarity summary
roles
dataset 1polarities
use dataset 1representative citing papers
Calculates off-shell pion electromagnetic form factors in Bethe-Salpeter formalism with separable kernel, verifies Ward-Takahashi identity, and compares cross section to data.
The Standard Model value for the muon anomalous magnetic moment is 116591810(43)×10^{-11}, 3.7σ below the Brookhaven experimental measurement.
citing papers explorer
-
Improved Standard-Model predictions for $\eta^{(\prime)}\to \ell^+ \ell^-$
Updated SM predictions yield Br(η→e⁺e⁻)=5.37(4)(2)[4]×10⁻⁹, Br(η→μ⁺μ⁻)=4.54(4)(2)[4]×10⁻⁶, Br(η'→e⁺e⁻)=1.80(2)(3)[3]×10⁻¹⁰, and Br(η'→μ⁺μ⁻)=1.22(2)(2)[3]×10⁻⁷, with a mild 1.6σ tension in the η→μ⁺μ⁻ channel.
-
Pion off-shell form factors
Calculates off-shell pion electromagnetic form factors in Bethe-Salpeter formalism with separable kernel, verifies Ward-Takahashi identity, and compares cross section to data.
-
The anomalous magnetic moment of the muon in the Standard Model
The Standard Model value for the muon anomalous magnetic moment is 116591810(43)×10^{-11}, 3.7σ below the Brookhaven experimental measurement.