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arXiv · 2110.11533

State mixing and masses of the $\pi^0$, $\eta$ and $\eta^\prime$ mesons from $n_f=1+1+1$ lattice QCD+QED

Z. R. Kordov·R. Horsley·W. Kamleh·Z. Koumi·Y. Nakamura·H. Perlt·P. E. L. Rakow·G. Schierholz·H. Stüben·R. D. Young·J. M. Zanotti
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Abstract

We present a lattice analysis of the light pseudoscalar mesons with consideration for the mixing between the flavour-neutral states $\pi^0$, $\eta$ and $\eta^\prime$. We extract the masses and flavour compositions of the pseudoscalar meson nonet in $n_f=1+1+1$ lattice QCD+QED around an SU(3)-flavour symmetric point, and observe flavour-symmetry features of the extracted data, along with preliminary extrapolation results for the flavour compositions at the physical point. A key result of this work is the observed mass splitting between the $\pi^0$ and $\eta$ on our ensembles, which is found to exhibit behaviour that is simply related to the corresponding flavour compositions.

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Z. R. Kordov, R. Horsley, W. Kamleh, Z. Koumi, Y. Nakamura, H. Perlt, P. E. L. Rakow, G. Schierholz, H. Stüben, R. D. Young, J. M. Zanotti. 2021-10-22. State mixing and masses of the $\pi^0$, $\eta$ and $\eta^\prime$ mesons from $n_f=1+1+1$ lattice QCD+QED. https://doi.org/10.1103/physrevd.104.114514

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