Radiative quark and lepton masses through soft supersymmetry breaking

Radiative origin of all quark and lepton masses through dark matter with flavor symmetry

The fundamental issue of the origin of mass for all quarks and leptons (including Majorana neutrinos) is linked to dark matter, odd under an exactly conserved Z2 symmetry which may or may not be derivable from an U(1)D gauge symmetry. The observable sector interacts with a proposed dark sector which consists of heavy neutral singlet Dirac fermions and suitably chosen new scalars. Flavor symmetry is implemented in a renormalizable context with just the one Higgs doublet (ϕ(+), ϕ(0)) of the standard model in such a way that all observed fermions obtain their masses radiatively through dark matter.

Higgs-mediated B0 --> &mgr;(+)&mgr;(-) in minimal supersymmetry

We demonstrate a new source for flavor-changing neutral currents within the minimal supersymmetric standard model. At moderate to large tanbeta, it is no longer possible to diagonalize the masses of the quarks in the same basis as their Yukawa couplings. This generates flavor-violating couplings of the form &bmacr;(R)d(L)straight phi and &bmacr;(R)s(L)straight phi where straight phi is any of the three neutral, physical Higgs bosons. These new couplings lead to rare processes in the B system such as B0-->&mgr;(+)&mgr;(-) and B0-&Bmacr;(0) mixing. We show that the latter are anomalously suppressed, while the former is in the experimentally interesting range, with an observable signal possible at Run II of the Tevatron if m(A) less, similar400-700 GeV.