U (1)A symmetry in two-doublet models, U bosons or light scalars, and ψ and Γ decays

psi and Gamma decays may be used to search for light neutral spin-1 or spin-0 bosons associated with a broken extra-U(1) symmetry, local or global, acting axially on quarks and leptons, as may be present in supersymmetric theories with a lambda H1H2S superpotential. Recent data on Gamma -> gamma + invisible neutral constrain an axial, pseudoscalar or scalar coupling to b to f(bA) < 4 x 10(-7)m(U) (MeV)/root B-inv, f(bp) < 4 x 10(-3)/root B-inv or f(bs) < 6 x 10(-3)/root B-inv, respectively. This also constrains, from universality properties, couplings to electrons to f(eA) < 4 x 10(-7)m(U) (MeV)/root B-inv, f(eP) < 4 x 10(-7)/root B-inv, or f(eS) < 6 x 10(-7)/root B-inv. The pseudoscalar a (possibly traded for a light gauge boson, or scalar particle) should then be, for invisible decays of the new boson, for > 96% singlet and < 4% doublet, for tan beta > 1. Or, more generally, < 4%/(tan(2) beta B-inv) doublet, which implies a very small rate for the corresponding psi decay. B(psi -> gamma neutral) B-inv less than or similar to 10(-6)/tan(4)beta. Similar results are obtained for new spin-1 or spin-0 neutral bosons decaying into mu(+)mu(-). (C) 2009 Elsevier B.V. All rights reserved.