Deep inside a neutron star, matter is squeezed so tightly that familiar protons and neutrons give way to new players. Hyperons are born there — particles that harbor a strange quark. The question of how much energy it takes to push such a hyperon out of the nuclear medium is far from idle: the answer determines whether the star holds up or collapses into a black hole.

You don't have to look to space to find the answer: you can do it right here on Earth. When a neutrino (that nearly undetectable particle) slams into an atomic nucleus, it sometimes spawns a hyperon right in the thick of the protons and neutrons. From there, it's like a billiard ball sent through a crowd: how quickly the ball emerges, gets stuck, or decays tells you about the jostling forces. In the SBND experiment and the future DUNE, scientists plan to catch such events and measure how strongly the nuclear medium attracts or repels two types of hyperons — lambda and sigma.

Calculations show that the potential for the lambda hyperon can be measured to an uncertainty of about 6 MeV. That's roughly one-hundredth of the energy of a dental X-ray. What's more, the systematic errors here are quite different from those in hypernucleus experiments, so the two methods can cross-check each other. With the sigma hyperon, things get trickier: uncertainties in scattering cross-sections muddy the signal, but the very possibility is already making detector plans worth revisiting.