Research in theoretical particle physics. Final report, May 1, 1983-May 31, 1985

A chiral non-linear Lagrangian containing non linearly transforming scalar mesons was constructed. The naturally induced SU(3)-breaking allowed a satisfactory discussion of pseudoscalar radiative decays, as well as scalar particle decays. A study was made of the consistency between the Schwinger-Dyson equation for the quark propagator and the Bethe-Salpeter equation for q anti q states. This led to the PCAC condition, as well as to good results for the ground state q anti q spectrum. The path integral derivation of the chiral anomalies with V, A, S, and P couplings was analyzed, and the removal of spurious Ward identities was achieved by appropriate choices of fermion basis. A study was made of the effects of the presence of an ultra-heavy new quark generation. This led to bounds on their couplings and to upper mass limits. Their influence on the D0-anti D0 mass difference and on CP-violation was also discussed. A derivation of the Wess-Zumino five-pseudoscalar action based on the quark loop expansion was presented. The same technique was used for the derivation of terms containing spin-one fields. Fields transforming either linearly or non-linearly were considered, and the experimental consequences were discussed