Orateur
Description
We present the most recent BABAR searches for reactions that could simultaneously explain the presence of dark matter and the matter-antimatter asymmetry in the Universe. This scenario predicts exotic $B$-meson decays of the kind $B\to\psi_{D} {\cal B}$, where $\cal{B}$ is an ordinary matter baryon (proton, $\Lambda$, or $\Lambda_c$) and $\psi_D$ is a dark-sector anti-baryon, with branching fractions accessible at the $B$ factories. 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 for $\psi_D$ masses between 0.5 and 4.3 GeV/c$^2$. The results are based on the full data set of about 470 million $B-\overline B$ pairs collected at the $\Upsilon(4S)$ resonance by the BABAR detector at the PEP-II collider.
