Speaker
Description
To achieve the high precision required for theoretical inputs into quantities such as muon g-2 and CKM matrix elements, lattice QCD calculations require a precise determination of the lattice scale. This requires a quantity that is measured experimentally to very high precision and match a lattice calculation onto the experimental value. One of the best choices of this quantity is the Omega baryon. To achieve the precision, systematic uncertainties, such as excited state contaminations to the ground state Omega mass, must be controlled.
In lattice calculations, the mass of the Omega baryon can be extracted using 2-point correlators. However, there are two issues: at large times, there is noise that grows exponentially; and at short times, there are higher energy states present. Using chiral perturbation theory methods with a heavy baryon Lagrangian, the excited state contamination of the Omega baryon can be quantified to understand the multiparticle state contributions on the ground state Omega mass. I will present a comparison on how well HBChPT relates to lattice QCD determination of the Omega mass from the Budapest–Marseille–Wuppertal collaboration using GEVP methods.