Speaker
Description
An analysis of about 211 million $B^{0}$-$\bar{B}^{0}$ pairs produced in $e^+e^-$ collisions at the $\Upsilon(4S)$ resonance and recorded by the $BABAR$ experiment is used to search for the decay $B^{0}\to\psi_{D}\Lambda$, which produces 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 $\Lambda$ baryon decaying into a proton and a charged pion is present in the signal $B$-meson side. The missing mass of signal $B_{sig}$ is considered as the mass of the dark particle $\psi_{D}$.The signal events of the decay $B^{0}\to\psi_{D}\Lambda$ are selected on the missing mass distribution in the range of 0.5 to 4.2 GeV/c$^2$ for 197 different $\psi_{D}$ mass hypotheses, and stringent upper limits on the decay branching fraction are derived.
| In-person participation | No |
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