Dmitri Diakonov, Jefferson Lab and NORDITA, Copenhagen 
Pentaquarks: a new kind of elementary particles?


For forty years, studies of elementary particles have indicated that all baryons (protons, neutrons...) can be made only of three quarks. However our analysis of the dynamics of the spontaneous chiral symmetry breaking in strong interactions has lead to a prediction of new nearly stable baryons made of five quarks. Several experiments prompted by our prediction support the existence of this new kind of elementary particles. In the talk both the underlying theory and experiments will be discussed as well as the implications for a better understanding of the subatomic world.