Semileptonic decays of charmed and beauty baryons with sterile neutrinos in the final state

Abstract

We obtain tree-level estimates of various differential branching ratios of heavy baryon decays with massive sterile neutrinos ${\nu }_x$ in the final state. Heavy sterile neutrinos can be searched for in heavy baryon decays with missing mass as a signature as well as in fixed target experiments, where heavy baryon decays contribute to sterile neutrino production, with sterile neutrino decays as a signature. Generally, charmed baryons are found to be less promising than charmed mesons, in contrast to b-hadrons. In the latter case, branching ratios of beauty mesons and baryons into sterile neutrinos are of the same order. As a consequence, at high energies beauty baryons give contribution to sterile neutrino production comparable to the contribution of beauty mesons (up to about 15%). Experimental limits on active-to-sterile mixing are quite strong for neutrinos lighter than D-meson but for heavier neutrinos they are weaker. As an example, for neutrino masses in the range 2 GeV $\lesssim m_{{\nu }_x}\lesssim 2.5$ GeV, current data imply that the bounds on ${\Lambda }_b$-hyperon branching ratios into sterile neutrinos are $\mathrm{Br}({\Lambda }_b\to {\Lambda }_c+e^{-}+{\nu }_x)\lesssim 1.3\cdot 10^{-5}-1.7\cdot 10^{-6}$ and $\mathrm{Br}({\Lambda }_b\to {\Lambda }_c+{\mu }^{-}+{\nu }_x)\lesssim 3.9\cdot 10^{-7}-1.4\cdot 10^{-7}$.

9 pages, 4 figures

References in corpus (2)

• How to find neutral leptons of the nuMSM?
• Heavy Flavour Hadro-Production from Fixed-Target to Collider Energies