Speaker
Description
Many hadronic observables are nowadays computed in lattice QCD with a sub-percent precision which requires the inclusion of isospin-breaking and electromagnetic effects. Most of the methods that implement the photon propagator in finite-volume lead to power-law suppressed finite size effects. These are due to the long-range nature of electromagnetism and make reliable predictions computationally demanding. This issue can be avoided by working with a regulated photon propagator (introducing a Pauli-Villars mass $\Lambda$) directly in continuum and infinite volume. This feature can be profitably exploited to improve the determination of leading-order electromagnetic corrections to several observables such as the HVP or nucleon masses. In this work we test this strategy for the charged/neutral pion mass difference $M_{\pi^+}-M_{\pi^0}$ using CLS $n_f=2+1$ ensembles. We show preliminary results addressing both the dependence on the regulator $\Lambda$ and the chiral-continuum extrapolation with pion masses between 160 and 280 MeV and lattice spacing in the range $[0.049,0.085]$ fm.
| Parallel Session (for talks only) | Quark and lepton flavor physics |
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