Speaker
Description
We present the most recent $BABAR$ searches for Dark-matter states with masses below the electroweak scale.The results are based on the full data set of about 470 $\text{fb}^{-1}$ collected at the $\Upsilon(4S)$ resonance by the $BABAR$ detector at the PEP-II collider.
They include, in particular, a search for decays like $B^{0}\to\psi_{D} {\cal B}$ where $\cal{B}$ is a baryon (proton, $\Lambda$, or $\Lambda_c$ ), which produce the dark matter particle ($\psi_{D}$) and baryogenesis simultaneously. The hadronic recoil method has been applied with one of the $B$ mesons from $\Upsilon(4S)$ decay fully reconstructed, while only one baryon is present in the signal $B$-meson side. The missing mass of signal $B$ meson is considered as the mass of the dark particle $\psi_{D}$. Stringent upper limits on the decay branching fraction are derived in the energy region between 0.5 and 4.2 GeV/c$^2$.
