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arXiv · 2108.05311

Lattice QCD Calculation of the Pion Mass Splitting

Xu Feng·Luchang Jin·Michael Joseph Riberdy
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Abstract

We use the infinite volume reconstruction method to calculate the charged/neutral pion mass difference. The hadronic tensor is calculated on lattice QCD and then combined with an analytic photon propagator, and the mass splitting is calculated with exponentially-suppressed finite volume errors. The calculation is performed using six gauge ensembles generated with $2+1$-flavor domain wall fermions, and five ensembles are at the physical pion mass. Both Feynman and Coulomb gauge are adopted in the calculation and result in a good agreement when the lattice spacing approaches zero. After performing the continuum extrapolation and examining the residual finite-volume effects, we obtain the pion mass splitting $\Delta m_\pi = 4.534(42)(43)~\mathrm{MeV}$, which agrees well with experimental measurements.

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Xu Feng, Luchang Jin, Michael Joseph Riberdy. 2021-08-11. Lattice QCD Calculation of the Pion Mass Splitting. https://doi.org/10.1103/physrevlett.128.052003

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