Experimental Tests of QCD Symmetries with Pions

by Prof. Bernstein Aron (MIT)

Monday 22 Jun 2015, 14:15 → 15:45 Europe/Berlin

3344 (TUM - Physics Department - Garching)

From Yukawa’s conjecture to the present, the pion has played a central role in hadronic physics. In QCD, as the lightest Nambu-Goldstone Boson it is closely associated with spontaneous chiral symmetry breaking. with many properties reflecting this. As the lightest hadron the neutral pion can primarily decay into two photons, enabling an experimental test of the lifetime that is dominated by the QCD chiral anomaly. A review of the present status of the theory and the experiments will be presented. The remainder of the talk will focus on the electromagnetic production of pions from nucleons. We have made a great deal of experimental progress in the past few years, and have confronted the theoretical calculations based on chiral symmetry breaking.