Extracting the chiral anomaly from
arXiv:2504.13827 · doi:10.1007/JHEP07(2025)095
Abstract
The strength of the interaction of three pions and a photon, is predicted by the axial anomaly in terms of the pion decay constant, a relation that is frequently used to constrain low-energy radiative processes involving pions, but only tested experimentally at the level. Here, we present a new avenue to test this prediction, via a fit of a dispersive description of the amplitude to data for . From the global fit to SND, CMD-2, and BaBar data we obtain , in agreement with the chiral prediction at the level of . We also consider dispersive fits to the recent data by Belle II, in which case we observe tensions with the dispersive constraints, the width parameters of and , and the chiral anomaly.
arXiv comment17 pages, 1 figure; journal version
References in corpus (69)
- The anomalous magnetic moment of the muon in the Standard Model
- The QCD axion, precisely
- The muon and : a new data-based analysis
- Refinements in electroweak contributions to the muon anomalous magnetic moment
- Reevaluation of the hadronic vacuum polarisation contributions to the Standard Model predictions of the muon g-2 and alpha(mZ) using newest hadronic cross-section data
- Hadronic light-by-light scattering contribution to the muon anomalous magnetic moment revisited
- The of charged leptons, and the hyperfine splitting of muonium
- Hadronic contribution to the muon anomalous magnetic moment to next-to-next-to-leading order
- Two-pion contribution to hadronic vacuum polarization
- The electroweak contributions to (g-2)_μ after the Higgs boson mass measurement
- Remarks on higher-order hadronic corrections to the muon g-2
- Dispersion relation for hadronic light-by-light scattering: two-pion contributions
- The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment from lattice QCD
- Three-pion contribution to hadronic vacuum polarization
- Dispersion relation for hadronic light-by-light scattering: pion pole
- Pseudoscalar-pole contribution to the : a rational approach
- Short-distance constraints for the HLbL contribution to the muon anomalous magnetic moment
- Longitudinal short-distance constraints for the hadronic light-by-light contribution to with large- Regge models
- Dispersion relation for hadronic light-by-light scattering: theoretical foundations
- Towards a data-driven analysis of hadronic light-by-light scattering
- Dispersive approach to hadronic light-by-light scattering
- Pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon
- Dispersive analysis of omega --> 3pi and phi --> 3pi decays
- Dispersive analysis of the pion transition form factor
- The anomalous chiral Lagrangian of order
- omega --> pi0 gamma* and phi --> pi0 gamma* Transition form factors in dispersion theory
- Fitting Parton Distribution Data with Multiplicative Normalization Uncertainties
- A new Parameterization for the Pion Vector Form Factor
- Dispersive analysis for
- Extracting the chiral anomaly from gamma pi --> pi pi
- Unified dispersive approach to real and virtual photon-photon scattering at low energy
- The decay pi0 to gamma gamma to next to leading order in Chiral Perturbation Theory
- Short-distance constraints on hadronic light-by-light scattering in the anomalous magnetic moment of the muon
- Chiral expansions of the pi0 lifetime
- Electromagnetic corrections in the anomaly sector
- Anomalous decay and scattering processes of the eta meson
- Model-independent approach to eta -> pi+ pi- gamma and eta' -> pi+ pi- gamma
- Kaon electromagnetic form factors in dispersion theory
- On the transition form factors of the axial-vector resonance and its decay into
- The resonant amplitude from Quantum Chromodynamics
- A new parametrization for the scalar pion form factors
- Hadronic vacuum polarization and vector-meson resonance parameters from
- Isospin-breaking effects in the two-pion contribution to hadronic vacuum polarization
- Radiative resonance couplings in
- Time-like and space-like electromagnetic form factors of nucleons, a unified description
- Calculation of the anomalous form factor
- A phenomenological estimate of isospin breaking in hadronic vacuum polarization
- Towards an improved understanding of
- Isospin-breaking effects in the three-pion contribution to hadronic vacuum polarization
- Electromagnetic corrections to gamma pi(+) -> pi(0) pi(+)
- Dispersion relation for hadronic light-by-light scattering: subleading contributions
- The anomalous process gamma pi -> pi pi to two loops
- Leading logarithms in the anomalous sector of two-flavour QCD
- The anomaly from lattice QCD and dispersion relations
- Chiral Anomaly and
- Dispersion relation for hadronic light-by-light scattering: and poles
- A dispersive analysis of and
- Dispersion relations for the hadronic VVA correlator
- On the scalar form factor beyond the elastic region
- A new determination of the anomalous amplitude via data
- Study of below 1 GeV using Integral Equation Approach
- Precision evaluation of the - and -pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muon
- Dispersive analysis of the Primakoff reaction
- From pole parameters to line shapes and branching ratios
- Axion-meson mixing in light of recent lattice - simulations and their two-photon couplings within chiral theory
- Hadronic light-by-light scattering in the anomalous magnetic moments of electron and
- Timelike form factor for the anomalous process
- Polarizabilities from kaon Compton scattering
- Axial anomaly and the interplay of quark loops with pseudoscalar and vector mesons in the gamma* --> pi+ pi0 pi- process