F. Strocchi

Locality, charges and quark confinement

Abstract General features of the Yang-Mills color theory suggested by Fritzsch, Gell-Mann and Leutwyler are discussed. It is shown that as a consequence of locality every observable is a color singlet and that the failure of the cluster property and consequently a q- q potential not decreasing at infinity are possible, consistently with locality, just because of the non abelian gauge character. A generalized cluster property is proved for Yang-Mills local field theories.

U (3) × U (3) breaking and 2 γ - decays of pseudoscalar mesons

Abstract The physical consequences of a U (3) × U (3) breaking term ϵ δ in the Hamiltonian H = H 0 + ϵ δ + ϵ i u i are investigated. Mass formulae are obtained and the η − η ′ mixing is shown to be governed by this term. The 2γ-decays of pseudo-scalar mesons are computed by using the above Hamiltonian. A significant test is the prediction of a very small rate E(1422) → 2 γ .

SU(2) chiral breaking and η → 3Π decay

Abstract A model independent calculation of the η → 3 Π decay rate is performed in the framework of SU(2) chiral breaking ( ϵ 3 u 3 ). The problem of accounting for the experimental value is resolved with a value of ϵ 3 in agreement with the baryon and meson e.m. mass differences.