b→stransitions: A new frontier for indirect supersymmetry searches

The present unitarity triangle fit, whose essential input is represented by the $\overrightarrow{s}d$ and $\overrightarrow{b}d$ transition processes, fully agrees with the SM. However, most of the phenomena involving $\overrightarrow{b}s$ transitions are still largely unexplored and hence $\overrightarrow{b}s$ phenomenology still constitutes a place for new physics manifestations, in spite of the tremendous experimental and theoretical progress on $\overrightarrow{B}{X}_s\gamma .$ We perform a systematic study of the $\mathrm{CP}$ conserving and violating supersymmetry (SUSY) contributions to $\overrightarrow{b}s$ processes in a generic minimal supersymmetric standard model (MSSM). We consider gluino exchange contributions including next-to-leading order QCD corrections and lattice hadronic matrix elements for $\Delta B=2\mathrm{}$ and $\Delta B=1\mathrm{}$ processes. We take into account all available experimental information on processes involving $\overrightarrow{b}s$ transitions $(\overrightarrow{B}{X}_s\gamma ,\overrightarrow{B}{X}_s{\mathcal{l}}^{+}{\mathcal{l}}^{-}$ and the lower bound on the $B_s-B_s$ mass difference $\Delta M_s).\mathrm{}$ We study the correlations among the relevant observables under scrutiny at present or in a not too far future: $\Delta M_s$ and the amount of $\mathrm{CP}$ violation in $\overrightarrow{B}\phi K_s,B_s\to J/\psi \phi ,\overrightarrow{B}{X}_s\gamma .$ In particular we discuss the recent data by BaBar and BELLE on the time-dependent $\mathrm{CP}$ asymmetry in the decay $\overrightarrow{B}\phi K_S$ which suggest a deviation from the SM expectation. Our results show that the processes involving $\overrightarrow{b}s$ transitions represent a splendid opportunity to constrain different MSSM realizations, and, even more important, that they offer concrete prospects to exhibit SUSY signals at B factories and hadron colliders in spite of all the past frustration in flavor changing neutral current searches of new physics hints.