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, ${\tilde{\chi }}_1^0$. 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 $B_s\to \varphi \gamma$. Direct search is similar to usual $\tilde{b}\to b{\tilde{\chi }}_1^0$, but existing bounds are weakened by ${\widetilde{sb}}_1\to s{\tilde{\chi }}_1^0$ possibility. All these effects could be studied soon at the Tevatron.

Comments: 4 pages, 3 eps figures, version to appear in PRD