Valentina Verduci
Speaker affiliation: 
University of Graz
Friday, December 13, 2013 - 16:15
Building 44 (Shackleton) Lect. Theatre B
Resonances and scattering states in lattice QCD: the pion-nucleon system

Most of the hadrons that constitute the QCD spectrum are unstable under strong interactions. Lattice QCD calculations have been historically treating these state as stable states, without taking into account their resonant nature and their coupled decay channels. In the last years new techniques have been developed and the study of two particle systems in lattice QCD has become an accessible challenge. I will present some results relative to the pion-nucleon coupled system in S-wave, which appears to be crucial for a better understanding of the negative parity nucleon spectrum. I will explain which are the main obstacles encountered in this type of calculation and why the distillation method and the phase shift analysis turn out to be essential tools in this approach.