ChPT loops for the lattice: pion mass and decay constant, HVP at finite volume and nn?-oscillations

摘要

I present higher loop order results for several calculations in Chiral perturbation Theory. 1) Two-loop results at finite volume for hadronic vacuum polarization. 2) A three-loop calculation of the pion mass and decay constant in two-flavour ChPT. For the pion mass all needed auxiliary parameters can be determined from lattice calculations of ππ -scattering. 3) Chiral corrections to neutron-anti-neutron oscillations.