The Optical Potential on the Lattice
  The extraction of hadron-hadron scattering parameters from lattice data by using the L\"uscher approach becomes increasingly complicated in the presence of inelastic channels. We propose a method for the direct extraction of the complex hadron-hadron optical potential on the lattice, which does not require the use of the multi-channel L\"uscher formalism. Moreover, this method is applicable without modifications if some inelastic channels contain three or more particles. 
Dimitri Agadjanov, Michael Doring, Maxim Mai, Ulf-G. Mei{\ss}ner,   Akaki Rusetsky
hep-lat hep-ph