Speaker: Daniel Robaina (TU Darmstadt) Title: Total Decay and transition rates from Lattice QCD Abstract: I will present a new technique for extracting total decay rates and transition rates into final states with any number of hadrons from Lattice QCD. The method involves the calculation of a finite volume Euclidean four-point function whose corresponding spectral function in the infinite-volume limit gives access to the observables of interest. The spectral function is estimated by solving an inverse problem. We advocate to use the Backus-Gilbert method to accomplish this. I will discuss in some detail its advantages and disadvantages and will explain how this method might work in practice by means of a simple toy model. Finally I will review some example applications for our method.