Speaker
David Albandea
(Helmholtz-Institut Mainz, GSI)
Description
The inclusion of isospin-breaking contributions is mandatory for achieving sub-percent precision in determinations of the hadronic vacuum polarization (HVP) and demands efficient computational strategies. In this talk, I compare two approaches: explicit $N_f = 1+1+1$ simulations with non-degenerate up and down quark masses, and the RM123 perturbative expansion in the quark mass splitting $\Delta m$ applied to a $N_f = 2+1$ ensemble. Using two CLS ensembles at the same lattice spacing, I compute several observables sensitive to strong isospin breaking, including the isovector-isoscalar HVP contribution $a_\mu^{\mathrm{HVP},38}$, and compare the statistical efficiency of both approaches.
Author
David Albandea
(Helmholtz-Institut Mainz, GSI)