Speaker
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 $B \rightarrow \psi_D \ \cal B$, 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 430 fb$^{−1}$ collected at the $\Upsilon(4S)$ resonance by the BABAR detector at the PEP-II collider.
