Messenger-matter Mixing Research Articles

Higgs boson of mass 125 GeV in gauge mediated supersymmetry breaking models with matter-messenger mixing

We investigate the effects of messenger-matter mixing on the lightest CP-even Higgs boson mass m_h in gauge-mediated supersymmetry breaking models. It is shown that with such mixings m_h can be raised to about 125 GeV, even when the superparticles have sub-TeV masses, and when the gravitino has a cosmologically preferred sub-keV mass. In minimal gauge mediation without messenger-matter mixing, realizing m_h = 125 GeV would require multi-TeV SUSY spectrum. The increase in $m_h$ due to messenger-matter mixing is maximal in the case of messengers belonging to 10+\bar{10} of SU(5) unification, while it is still significant when they belong to $5+\bar{5}$ of SU(5). Our results are compatible with gauge coupling unification, perturbativity, and the unification of messenger Yukawa couplings. We embed these models into a grand unification framework with a U(1) flavor symmetry that addresses the fermion mass hierarchy and generates naturally large neutrino mixing angles. While SUSY mediated flavor changing processes are sufficiently suppressed in such an embedding, small new contributions to K^0-\bar{K^0} mixing can resolve the apparent discrepancy in the CP asymmetry parameters \sin2\beta and \epsilon_K.

ON ELECTROWEAK BARYOGENESIS IN GAUGE MEDIATED MODELS WITH MESSENGER–MATTER MIXING

We consider feasibility of electroweak baryogenesis in gauge mediated supersymmetry breaking models with messenger–matter mixing. We present a class of models where electroweak baryogenesis produces sufficient amount of baryon asymmetry. The main features of these models are (i) large mixing between messengers and right stop and (ii) fairly narrow region of viable tan β.

On Electroweak Baryogenesis in Gauge Mediated Models with Messenger-Matter Mixing

We consider feasibility of electroweak baryogenesis in gauge mediated supersymmetry breaking models with messenger-matter mixing. We present a class of models where electroweak baryogenesis produces sufficient amount of baryon asymmetry. The main features of these models are ({\it i}) large mixing between messengers and right stop and ({\it ii}) fairly narrow region of viable $\tan\beta$.

Flavor violation and tan β in gauge mediated models with messenger-matter mixing

We consider the Minimal Gauge Mediated Model (MGMM) with either fundamental or antisymmetric messenger multiplets and study consequences of messenger-matter mixing. We find that in these models, unlike MGMM without mixing, a wide range of tan β is allowed. It is shown that existing experimental limits on processes with lepton flavor violation, and on K 0- K 0 , D 0- D 0 and B 0- B 0 mixing place significant constraints on relevant coupling constants and mixing parameters. On the other hand, the contributions of the messenger-matter mixing to the rates of τ → eγ, τ → μγ and b → sy may be well below the present experimental limits depending on the value of tan β. We also point out the possibility of sizeable slepton oscillations in this model.

Messenger-matter mixing and lepton flavor violation

We consider the Minimal Gauge Mediated Model (MGMM) with messenger-matter mixing and find that existing experimental limits on μ → eγ decay and μ – e -conversion place significant constraints on relevant coupling constants. On the other hand, the rates of τ → eγ and τ → μγ in MGMM are well below the existing limits. We also point out the possibility of sizeable slepton oscillations in this model.