Extracting the chiral anomaly from e + e − → 3π
Abstract The strength of the interaction of three pions and a photon, F 3π 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 10% level. Here, we...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2025-07-01
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| Series: | Journal of High Energy Physics |
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| Online Access: | https://doi.org/10.1007/JHEP07(2025)095 |
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| author | Martin Hoferichter Bai-Long Hoid Bastian Kubis |
| author_facet | Martin Hoferichter Bai-Long Hoid Bastian Kubis |
| author_sort | Martin Hoferichter |
| collection | DOAJ |
| description | Abstract The strength of the interaction of three pions and a photon, F 3π 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 10% level. Here, we present a new avenue to test this prediction, via a fit of a dispersive description of the γ ∗ → 3π amplitude to data for e + e − → 3π. From the global fit to SND, CMD-2, and BaBar data we obtain F 3π = 33.1(1.7) GeV−3, in agreement with the chiral prediction at the level of 5%. 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 ω and ϕ, and the chiral anomaly. |
| format | Article |
| id | doaj-art-7284cc31f0d145368df06b3a9dfadbe6 |
| institution | Kabale University |
| issn | 1029-8479 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj-art-7284cc31f0d145368df06b3a9dfadbe62025-08-20T03:45:44ZengSpringerOpenJournal of High Energy Physics1029-84792025-07-012025711810.1007/JHEP07(2025)095Extracting the chiral anomaly from e + e − → 3πMartin Hoferichter0Bai-Long Hoid1Bastian Kubis2Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of BernInstitut für Kernphysik and PRISMA+ Cluster of Excellence, Johannes Gutenberg UniversitätHelmholtz-Institut für Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universität BonnAbstract The strength of the interaction of three pions and a photon, F 3π 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 10% level. Here, we present a new avenue to test this prediction, via a fit of a dispersive description of the γ ∗ → 3π amplitude to data for e + e − → 3π. From the global fit to SND, CMD-2, and BaBar data we obtain F 3π = 33.1(1.7) GeV−3, in agreement with the chiral prediction at the level of 5%. 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 ω and ϕ, and the chiral anomaly.https://doi.org/10.1007/JHEP07(2025)095Chiral LagrangianPrecision QED |
| spellingShingle | Martin Hoferichter Bai-Long Hoid Bastian Kubis Extracting the chiral anomaly from e + e − → 3π Journal of High Energy Physics Chiral Lagrangian Precision QED |
| title | Extracting the chiral anomaly from e + e − → 3π |
| title_full | Extracting the chiral anomaly from e + e − → 3π |
| title_fullStr | Extracting the chiral anomaly from e + e − → 3π |
| title_full_unstemmed | Extracting the chiral anomaly from e + e − → 3π |
| title_short | Extracting the chiral anomaly from e + e − → 3π |
| title_sort | extracting the chiral anomaly from e e 3π |
| topic | Chiral Lagrangian Precision QED |
| url | https://doi.org/10.1007/JHEP07(2025)095 |
| work_keys_str_mv | AT martinhoferichter extractingthechiralanomalyfromee3p AT bailonghoid extractingthechiralanomalyfromee3p AT bastiankubis extractingthechiralanomalyfromee3p |