Phenomenology of flavor-mediated supersymmetry breaking - art. no. 075011

The phenomenology of a new economical supersymmetric model that utilizes dy namical supersymmetry breaking and gauge mediation for the generation of th e sparticle spectrum and the hierarchy of fermion masses is discussed. Simi larities between the communication of supersymmetry breaking through a mess enger sector and the generation of flavor using the Froggatt-Nielsen (FN) m echanism are exploited, leading to the identification of vector-like messen ger fields with FN fields and the messenger U(1) as a flavor symmetry. An i mmediate consequence is that the first and second generation scalars acquir e flavor-dependent masses, but do not violate flavor changing neutral curre nt bounds since their mass scale, consistent with ''effective supersymmetry ," is of order 10 TeV. We define and advocate a ''minimal flavor-mediated m odel" (MFMM), recently introduced in the literature, which successfully acc ommodates the small flavor-breaking parameters of the standard model using order 1 couplings and ratios of flavon field VEVs. The mediation of supersy mmetry breaking occurs via two-loop logarithm-enhanced gauge-mediated contr ibutions, as well as several one-loop and two-loop Yukawa-mediated contribu tions for which we provide analytical expressions. The MFMM is parametrized by a small set of masses and couplings, with values restricted by several model constraints and experimental data. Full two-loop renormalization grou p evolution is performed, correctly taking into account the negative two-lo op gauge contributions from heavy first and second generations. Electroweak symmetry is radiatively broken with the value of mu determined by matching to the Z mass. The weak scale spectrum is generally rather heavy, except f or the lightest Higgs boson, the lightest stau, the lightest chargino, the lightest two neutralinos, and of course a very light gravitino. The next-to -lightest sparticle always has a decay length that is larger than the scale of a detector, and is either the lightest stau or the lightest neutralino. Similar to ordinary gauge-mediated models, the best collider search strate gies are, respectively, inclusive production of at least one highly ionizin g track or events with many taus plus missing energy. In addition, D-0 <->D -0 mixing is also a generic low energy signal. Finally, the dynamical gener ation of the neutrino masses is briefly discussed.