Accelerator neutrinos as a probe of in-medium hyperon potentials

Charged-current (anti)neutrino interactions create $\mathrm{\Lambda }$ and $\mathrm{\Sigma }$ hyperons \emph{inside} the nucleus, making hyperon final-state interactions a terrestrial probe of the in-medium potentials that govern hyperon onset in neutron stars. In the StrangeMC simulation the trapped-$\mathrm{\Lambda }$ fraction, escaping hyperon momenta, and a kaon-vetoed ${\mathrm{\Sigma }}^{+}$ tag respond monotonically to $U_{\mathrm{\Lambda }}$ and $U_{\mathrm{\Sigma }}$ at SBND and DUNE. Marginalised over the low-density slope, a forecast gives $\delta U_{\mathrm{\Lambda }}\approx 6\text{MeV}$ with systematics distinct from hypernuclear data; $U_{\mathrm{\Sigma }}$ is limited by hyperon–nucleon cross sections.