U_A(1) Anomaly in Hot and Dense QCD and the Critical Surface
U_A(1) Breaking Effects on the Light Scalar Meson Spectrum
U_A(1) Problems and Gluon Topology - Anomalous Symmetry in QCD
U_A(1) Symmetry Breaking and eta, eta prime mesons in the Bethe-Salpeter Approach
U_A(1) symmetry breaking, scalar mesons and the nucleon spin problem in an effective chiral field theory
U_{PMNS} = U_ell^dagger U_nu