SUSY Flavor Problem Research Articles

A natural framework for bi-large neutrino mixing

In this Letter we present a “natural” framework for obtaining bi-large neutrino mixing incorporating the Frampton–Glashow–Yanagida neutrino mass matrix ansatz. We show that an SU(2)×U(1) family symmetry can provide the desired FGY neutrino mass ansatz in a minimal supersymmetric standard model. We also show how to obtain an approximate FGY ansatz in an SO(10) SUSY GUT. In this context, the same SU(2)×U(1) family symmetry also generates the hierarchy of fermion masses as well as ameliorating SUSY flavor problems.

Supersymmetry breaking and the SUSY flavour problem

Nonuniversality in the soft breaking terms is a generic feature in softly broken Supersymmetry. In particular, we show here that trilinear couplings are always nonuniversal in a theory that explains the Yukawa hierarchy in the frame of a spontaneously broken flavour symmetry. We analyse the constraints from low energy experiments and we find that large SUSY contributions are expected in the μ → eγ transition in the near future with SUSY masses around the TeV scale.

SUSY breaking in warped geometry, superconformal dynamics and SUSY flavor problem

SUSY breaking in warped geometry, superconformal dynamics and SUSY flavor problem

A Solution to SUSY Flavor Problem based on Supersymmetric Gauge Dynamics

A Solution to SUSY Flavor Problem based on Supersymmetric Gauge Dynamics

DECOUPLING SOLUTION TO SUSY FLAVOR PROBLEM VIA EXTRA DIMENSIONS

We discuss the decoupling solution to SUSY flavor problem in the fat brane scenario. We present a simple model to yield the decoupling sfermion spectrum in a five-dimensional theory. Sfermion masses are generated by the overlap between the wave functions of the matter fields and the chiral superfields on the SUSY breaking brane. Two explicit examples of the spectrum are given.

Nonuniversal soft parameters in the brane world and the flavor problem in supergravity

We consider gravity mediated supersymmetry (SUSY) breaking in 5D spacetime with two 4D branes B1 and B2 separated in the extra dimension. Using an off-shell 5D supergravity (SUGRA) formalism, we argue that the SUSY breaking scales could be nonuniversal even at the fundamental scale in a brane world setting, since SUSY breaking effects could be effectively localized. As an application, we suggest a model in which the two light chiral minimal supersymmetric standard model generations reside on B1, while the third generation is located on B2, and the Higgs multiplets as well as gravity and gauge multiplets reside in the bulk. For SUSY breaking of the order of 10--20 TeV caused by a hidden sector localized at B1, the scalars belonging to the first two generations can become sufficiently heavy to overcome the SUSY flavor problem. SUSY breaking on B2 from a different localized hidden sector gives rise to the third generation soft scalar masses of the order of 1 TeV. Gaugino masses are also of the order of 1 TeV if the size of the extra dimension is $\ensuremath{\sim}{10}^{\ensuremath{-}16}{\mathrm{GeV}}^{\ensuremath{-}1}.$ As in 4D effective supersymmetric theory, an adjustment of TeV scale parameters is needed to realize the 100 GeV electroweak symmetry breaking scale.

Aspects of supersymmetric models with a radiatively driven inverted mass hierarchy

A promising way to reconcile naturalness with a decoupling solution to the SUSY flavor and CP problems is suggested by models with a radiatively driven inverted mass hierarchy (RIMH). The RIMH models arise naturally within the context of SUSY SO(10) grand unified theories. In their original form, RIMH models suffer from two problems: 1.) obtaining the radiative breakdown of electroweak symmetry, and 2.) generating the correct masses for third generation fermions. The first problem can be solved by the introduction of SO(10) D-term contributions to scalar masses. We show that correct fermion masses can indeed be obtained, but at the cost of limiting the magnitude of the hierarchy that can be generated. We go on to compute predictions for the neutralino relic density as well as for the rate for the decay $b\to s\gamma$, and show that these yield significant constraints on model parameter space. We show that only a tiny corner of model parameter space is accessible to Fermilab Tevatron searches, assuming an integrated luminosity of 25~$fb^{-1}$. We also quantify the reach of the CERN LHC collider for this class of models, and find values of $m_{\tg}\sim 1600$ GeV to be accessible assuming just 10 fb$^{-1}$ of integrated luminosity. In an Appendix, we list the two loop renormalization group equations for the MSSM plus right handed neutrino model that we have used in our analysis.