Flavor violation and $\tan \beta$ in gauge mediated models with messenger-matter mixing

Abstract

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, wide range of $\tan \beta$ is allowed. It is shown that existing experimental limits on processes with lepton flavor violation, and on $K^0-{\bar{K}}^0$, $D^0-{\bar{D}}^0$ and $B^0-{\bar{B}}^0$ - 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 $\tau \to e\gamma$, $\tau \to \mu \gamma$ and $b\to s\gamma$ may be well below the present experimental limits depending on the value of $\tan \beta$. We also point out the possibility of sizeable slepton oscillations in this model.

Comments: 25 pages, 3 figures; the cases of high and low $\tan \beta$ are considered separately, the limits are stronger for high $\tan \beta$