SEMINAR    Wednesday March 28th, 2007 - h. 14:30 Auletta A-1 J. HOSEK (Nuclear Physics Institute, ASCR) Dynamical Breakdown of Abelian Gauge Chiral Symmetry by Strong Yukawa Couplings Abstract In an Abelian chirally and gauge-invariant anomaly-free model we demonstrate that strong Yukawa couplings between massless fermion fields and a massive scalar carrying the axial charge generate dynamically vastly different fermion masses and the gauge boson mass.