Accounting for isospin-breaking corrections is critical for achieving subpercent precision in lattice computations of hadronic observables. A way to include QED and strong-isospin-breaking corrections in lattice QCD calculations is to impose C⋆ boundary conditions in space. Here, we demonstrate the computation of a selection of meson and baryon masses on two QCD and five QCD+QED gauge ensembles in this setup, which preserves locality, gauge and translational invariance all through the calculation. The generation of the gauge ensembles is performed for two volumes, and three different values of the renormalized fine-structure constant at the U-symmetric point, corresponding to the SU(3)-symmetric QCD in the two ensembles where the electromagnetic coupling is turned off. We also present our tuning strategy and, to the extent possible, a cost analysis of the simulations with C⋆ boundary conditions.

RC C R * collaborationWe present two novelties in our analysis of fully dynamical QCD+QED ensembles with C ★ boundary conditions. The first one is the explicit computation of the sign of the Pfaffian. We present an algorithm that provides a significant speedup compared to traditional methods. The second one is a reweighting of the mass in the context of the RHMC. We have tested the techniques on both pure QCD and QCD+QED ensembles with pions at ± ≈ 400 MeV, a lattice spacing of ≈ 0.05 fm, a fine-structure constant of R = 0 and 0.04.

RC C R * collaborationWe present preliminary results for the determination of the leading strange and charm quarkconnected contributions to the hadronic vacuum polarization contribution to the muon's 𝑔 − 2. Measurements are performed on the RC ★ collaboration's QCD ensembles, with 3 + 1 flavors of 𝑂 (𝑎) improved Wilson fermions and C ★ boundary conditions. The HVP is computed on a single value of the lattice spacing and two lattice volumes at unphysical pion mass. In addition, we compare the signal-to-noise ratio for different lattice discretizations of the vector current.

RC C R * collaborationWe give an update on the ongoing effort of the RC ★ collaboration to generate fully dynamical QCD+QED configurations with C ★ boundary conditions using the openQ ★ D code. The simulations are tuned to the U-symmetric point (𝑚 𝑑 = 𝑚 𝑠 ) with pions at 𝑚 𝜋 ± ≈ 400 MeV. The splitting of the light mesons is used as one of three tuning observables and fixed to 𝑚 𝐾 0 − 𝑚 𝐾 ± ≈ 5 MeV and 𝑚 𝐾 0 − 𝑚 𝐾 ± ≈ 25 MeV on ensembles with renormalized electromagnetic coupling 𝛼 R ≈ 𝛼 phys. and 𝛼 R ≈ 5.5𝛼 phys. respectively. We will discuss some details concerning our tuning strategy and present the calculation of the meson and baryon masses. Finally, we will also present a cost analysis for our simulations. More technical details on finite-volume effects and the tuning can be found in A. Cotellucci's proceedings [1].

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