QCD tests from pion reactions on few-nucleon systems

Abstract

We show on two examples, namely a calculation for charge symmetry breaking in pn->d pi^0 that allows one to extract the quark mass difference induced part of the proton--neutron mass difference and a high precision calculation for pion--deuteron scattering and its implications for the value of the charged pion--nucleon coupling constant, how QCD tests can be performed from low energy hadronic observables.

Comments: 9 pages; Invited talk at workshop CHIRAL'10, Valencia (Spain), June 21-24, 2010