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 low-mass dark sector particle (ψD) with a nonzero baryonic charge. We present a search for this new state in B+→Λc+ψD decays using data collected at the ϒ(4S) resonance by the BABAR detector at SLAC, corresponding to an integrated luminosity of 431.0 fb-1. The search leverages the full reconstruction of the B- meson in ϒ(4S)→B+B- decays, accompanied by the reconstruction of a Λc+, to infer the presence of ψD. No significant signal is observed, and limits on the B+→Λc+ψD branching fraction are set at the level of 1.6×10-4 at 90% confidence level for 0.94<2.99 GeV. These results set strong constraints on the parameter space allowed by B-meson baryogenesis.
Search for baryogenesis and dark matter in B+ → Λc+ +invisible decays
Gaz A.;Margoni M.;Simi G.;Simonetto F.;Stroili R.;Zani L.;
2025
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 low-mass dark sector particle (ψD) with a nonzero baryonic charge. We present a search for this new state in B+→Λc+ψD decays using data collected at the ϒ(4S) resonance by the BABAR detector at SLAC, corresponding to an integrated luminosity of 431.0 fb-1. The search leverages the full reconstruction of the B- meson in ϒ(4S)→B+B- decays, accompanied by the reconstruction of a Λc+, to infer the presence of ψD. No significant signal is observed, and limits on the B+→Λc+ψD branching fraction are set at the level of 1.6×10-4 at 90% confidence level for 0.94<2.99 GeV. These results set strong constraints on the parameter space allowed by B-meson baryogenesis.Pubblicazioni consigliate
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