Neutrino Oscillation in a Whey Medium: Surprising Flavor Changes Detected

The SUDAN Experiment: Solar Neutrinos and Dairy

Neutrinos are elusive fundamental particles that come in three types, or 'flavors': electron, muon, and tau. As they travel through space, they oscillate between these flavors. This phenomenon is well-established and studied using detectors like Super-Kamiokande, often filled with pure water. The WICC's Subsurface Undulant Dairy And Neutrino (SUDAN) experiment replaces the water with filtered cheese whey, the liquid byproduct of cheese making. Whey is a complex soup of water, lactose, proteins (like beta-lactoglobulin), minerals, and lactic acid.

We hypothesized that the molecular and ionic environment of whey might interact with the neutrino's weak nuclear force in a novel way, potentially via a yet-undiscovered 'dairy force' or by modifying the local effective density experienced by the neutrino as it propagates. Even a tiny alteration in oscillation probability could point to new physics beyond the Standard Model.

Data from the Whey Tank

The SUDAN detector is a 50,000-gallon stainless steel tank filled with ultra-pure, de-gassed whey, lined with photomultiplier tubes. It sits deep underground to shield from cosmic rays. Neutrinos from the sun and cosmic sources pass through it. Occasionally, a neutrino interacts with an atom in the whey, producing a faint flash of Cherenkov radiation, which is detected. The pattern of these flashes reveals the flavor of the neutrino at the moment of interaction.

After two years of data collection, we have a significant result. The ratio of detected muon neutrinos to electron neutrinos in the whey tank is 8.3% lower than predicted by the standard oscillation model calibrated with water-based detectors. This indicates that neutrinos are oscillating away from the muon flavor more rapidly in the whey medium. The tau neutrino flux, while harder to detect directly, is inferred to be correspondingly higher. The whey appears to be 'seasoning' the neutrinos, altering their flavor profile.

• Possible Mechanism 1: The lactose molecules in whey act as a chiral medium, preferentially interacting with right-handed sterile neutrinos (a hypothetical fourth type), thereby changing the effective mixing angles for the active flavors.
• Possible Mechanism 2: The dissolved lactic acid creates a slight negative charge bias in the medium, which couples to the neutrino's magnetic moment (if it has one), causing a precession effect akin to the MSW effect in solar physics.
• Implication for Astrophysics: Our models of neutrino production in supernovae may be incorrect if the stellar plasma has whey-like properties in its later stages of collapse.

This discovery has sent ripples through the particle physics community. We are now preparing an upgraded experiment, SUDAN-II, which will use whey from different cheese types (goat, sheep, cow) and at different pH levels to map the 'oscillation landscape'. The humble byproduct of cheese making, often discarded or used for protein powder, may be the most sensitive neutrino detector medium yet discovered. It seems the path to understanding the universe's most ghostly particles runs straight through the dairy.