814 Bayesian Analysis of Hadronic Lattice Correlation Functions

The axial vector coupling gA is the strength of the coupling to the weak axial current of the Standard Model. It occurs in several phenomena, for example in neutron or pion decays or in the Goldberger-Treiman relation [1], which provides a connection between weak and strong interaction quantities. Since gA appears so frequently, it has become a benchmark quantity for checking results from Lattice Quantum Chromodynamics. The aim of this project is to obtain an estimate for the axial coupling constant gA by de- termining the parameters of the models for the spectral representations of the two- and three-point functions presented in the next section. The parameter values are obtained by numerical fitting in a Bayesian framework. The procedure is based on a current preprint, which is, unless otherwise stated, the main source of information for this re- port. The fitting method is based on constrained curve fitting.