A search for baryogenesis and dark matter in $B^{+}\to {\Lambda }_c^{+}+\mathrm{invisible}$ decays

Abstract

A mechanism of baryogenesis and dark matter production via $B$-meson oscillations and decays has recently been proposed to explain the observed dark matter abundance and matter-antimatter asymmetry in the universe. This mechanism introduces a light dark sector particle (${\psi }_D$) with a non-zero baryonic charge. We present a search for this new state in $B^{+}\to {\Lambda }_c^{+}{\psi }_D$ decays using data collected at the ${\rm Y}(4S)$ resonance by the BABAR detector at SLAC, corresponding to an integrated luminosity of $431.0{\mathrm{fb}}^{-1}$. The search leverages the full reconstruction of the $B^{-}$ meson in ${\rm Y}(4S)\to B^{+}{B}^{-}$ decays, accompanied by the reconstruction of a ${\Lambda }_c^{+}$, to infer the presence of ${\psi }_D$. No significant signal is observed, and limits on the $B^{+}\to {\Lambda }_c^{+}{\psi }_D$ branching fraction are set at the level of $1.6\times 10^{-4}$ at 90% confidence level for $0.94<m_{{\psi }_D}<2.99$ GeV. These results set strong constraints on the parameter space allowed by $B$-meson baryogenesis.

7 pages, 5 figures, published version

Cited by in corpus (1)

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