Probes of the Dark Sector at Flavor Facilities

Before we turn to non-B physics probes, we detour from our main theme of \(b\rightarrow s\) loop probes of New Physics, and give some account of a special arena for probing the Dark Sector, starting with the decays of bottomonium, namely \(\varUpsilon (nS)\), \(n =1-3\). As we have mentioned in Sect. 5.3, the CDMS/DAMA type of approaches to Dark Matter (DM) search are not sensitive to light DM. The bottomonium system offers to (partially) cover such a window. At the same time, the related exotic Higgs sector can also be probed. These suggestions have led the Belle and BaBar experiments to make dedicated data runs on \(\varUpsilon (nS)\) resonances below the \(\varUpsilon (4S)\).