Rare decay π^0 \to e^+e^- as a Test of Standard Model

Abstract

Experimental and theoretical progress concerning the rare decay π^0 \to e^+e^- is briefly reviewed. It includes the latest data from KTeV and a new model independent estimate of the decay branching which show the deviation between experiment and theory at the level of $3.3\sigma$. The predictions for ηand η' decays into lepton pair are presented. We also comment on the impact on the pion rare decay estimate of the BABAR collaboration on the pion transition form factor at large momentum transfer.

11 pages, 2 figures, extended version of the talk given at "New Physics and Quantum Chromodynamics at External Conditions" conference, May 3-6, 2009, Dnipropetrovsk, Ukraine

References in corpus (8)

• U-boson production in e+e- annihilations, psi and Upsilon decays, and Light Dark Matter
• Measurement of the gamma gamma* --> pi0 transition form factor
• The sky distribution of positronium annihilation continuum emission measured with SPI/INTEGRAL
• Measurement of the rare decay pi0 -> e+ e-
• Rare decay pi0 -> e+e-: theory confronts KTeV data
• Complete structure dependent analysis of the decay $P\to l^{+}{l}^{-}$
• QED radiative corrections to the decay pi^0 to e^+e^-
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Cited by in corpus (33)

• Measurement of the gamma gamma* --> eta and gamma gamma* --> eta' transition form factors
• Evolved QCD predictions for the meson-photon transition form factors
• γ*γ\rightarrow π^0 transition form factor at low-energies from a model-independent approach
• Comparing antithetic trends of data for the pion-photon transition form factor
• The VV'P form factors in resonance chiral theory and the pi-eta-eta' light-by-light contribution to the muon g-2
• Pion-photon transition---the new QCD frontier
• The pseudoscalar hadronic channel contribution of the light-by-light process to the muon (g-2) within the nonlocal chiral quark model
• Can we understand an auxetic pion-photon transition form factor within QCD? BaBar faces Belle
• Axial anomaly as a collective effect of meson spectrum
• Systematic estimation of theoretical uncertainties in the calculation of the pion-photon transition form factor using light-cone sum rules
• Transition Form Factors and Mixing of Pseudoscalar Mesons from Anomaly Sum Rule
• Pion transition form factor at the two-loop level vis-à-vis experimental data
• Di-electron spectrum at mid-rapidity in $p+p$ collisions at $\sqrt{s}=200$ GeV
• Spacelike and timelike form factors for the $({\pi }^0,\eta ,{\eta }^{\prime })\to {\gamma }^{\ast }\gamma$ transitions in the light-front quark model
• Chiral Anomaly Effects and the BaBar Measurements of the $\gamma {\gamma }^{\ast }\to {\pi }^0$ Transition Form Factor
• How the recent BABAR data for P to γγ* affect the Standard Model predictions for the rare decays P to l+l-
• Pion to photon transition form factors with basis light-front quantization
• Search for the ${\eta }^{\prime }\to e^{+}{e}^{-}$ decay with the SND detector
• Pion transition form factor in the constituent quark model
• Model analysis of the world data on the pion transition form factor
• Influence of confining gluon configurations on the $P\to {\gamma }^{\ast }\gamma$ transition form factors
• Gluonic components of the pion and the transition form factor ${\gamma }^{\ast }{\gamma }^{\ast }\to {\pi }^0$
• Photon-to-pion transition form factor and pion distribution amplitude from holographic QCD
• Pseudoscalar meson form factors and decays
• Search for the process ${\mathbf{e}}^{+}{\mathbf{e}}^{-}\to \eta$
• Muon g-2, rare decays P \to l^+l^- and transition form factors P \to γγ^*
• Chiral anomaly and the pion properties in the light-front quark model
• A model of a transition neutral pion formfactor measured in annihilation and scattering channels
• Pion-photon transition form factor using light-cone sum rules: theoretical results, expectations, and a global-data fit
• Two-loop contribution to the pion transition form factor vs. experimental data
• On a search for the $\eta \to e^{+}{e}^{-}$ decay at the VEPP-2000 $e^{+}{e}^{-}$ collider
• Novel insights into the $\gamma {\gamma }^{\ast }\to {\pi }^0$ transition form factor
• Limit on the pion distribution amplitude