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arXiv · 2411.06737

Isospin-breaking contribution to the model-independent axion-photon-photon coupling in $U(3)$ chiral theory

Rui Gao·Jin Hao·Chun-Gui Duan·Zhi-Hui Guo·J. A. Oller·Hai-Qing Zhou
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Abstract

We pursue the calculation of the model-independent component of the axion-photon-photon coupling in the $U(3)$ chiral perturbation theory up to next-to-leading order, with the emphasis on the isospin breaking effect. The mixing of the $\pi^0$-$\eta$-$\eta'$-axion system is revised as well by working out the complete linear isospin-breaking terms. Our calculation shows that the isospin-breaking correction to the axion-photon-photon coupling amounts to more than 15%, comparing with the result in the isospin limit.

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Rui Gao, Jin Hao, Chun-Gui Duan, Zhi-Hui Guo, J. A. Oller, Hai-Qing Zhou. 2024-11-11. Isospin-breaking contribution to the model-independent axion-photon-photon coupling in $U(3)$ chiral theory. https://arxiv.org/abs/2411.06737

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