HEP In the literature: open

Do GeV-scale heavy neutral leptons realize low-scale leptogenesis?

In plain words

In one scenario, heavy partners of neutrinos with masses near a few proton masses created the asymmetry. Such particles could be made at accelerators and seen decaying.

Precise statement

Determine whether heavy neutral leptons N with $M_N \sim 0.1\ \text{to}\ 100\ \mathrm{GeV}$ and active-sterile mixing $U^2$ in the range where resonant or oscillation-based (ARS) leptogenesis gives $\eta_B \sim 6e-10$ exist. An answer is a discovery with measured $M_N$, $U_e^2$, $U_{\mu}^2$, $U_{\tau}^2$ consistent with that region, or its exclusion.

What would settle it

Beam-dump and collider searches (SHiP, displaced-vertex searches at LHC, FCC-ee at the Z pole) covering the leptogenesis region.

Status in the literature

Unverified note

SHiP was approved at CERN in 2024 for operation in the 2030s.