Impact of a Light Strange-Beauty Squark on B_s Mixing and Direct Search

Abstract

If one has Abelian flavor symmetry, $s_R$-$b_R$ mixing could be near maximal. This can drive a "strange-beauty" squark ($\widetilde{sb}_{1}$) to be rather light, but still evade the $b\to s\gamma$ constraint. Low energy constraints imply that all other superpartners are at TeV scale, except for a possibly light neutralino, $\widetilde \chi_1^0$. Whether light or heavy, the $\widetilde{sb}_{1}$ can impact on the $B_s$ system: $\Delta m_{B_s}$ and indirect CP phase, even for $B_s \to \phi\gamma$. Direct search is similar to usual $\tilde b \to b\widetilde \chi_1^0$, but existing bounds are weakened by $\widetilde{sb}_{1} \to s\widetilde \chi_1^0$ possibility. All these effects could be studied soon at the Tevatron.