Speaker
Description
Isospin breaking, arising from electromagnetic interactions and the difference between the up- and down-quark masses, leads to small but phenomenologically important mass differences between hadrons. As lattice QCD calculations reach percent-level precision, these effects need to be included systematically.
In this work, we study isospin-breaking mass splittings within spin-1/2 and spin-3/2 baryon flavor-SU(2) multiplets using lattice QCD. Electromagnetic and strong-isospin-breaking corrections are incorporated perturbatively around an isospin-symmetric lattice QCD calculation, using twisted-mass gauge ensembles tuned close to the physical isospin-symmetric point. Results at several lattice spacings allow us to investigate discretization effects and enable a controlled approach to the continuum limit. The use of several ensembles further allows us to investigate systematic uncertainties and compare our results with experimentally observed mass splittings.