We can use ordinary sugar in the search for dark matter

Researchers have devised a novel approach to hunt for dark matter by utilizing large crystals of sucrose, or table sugar—though their findings so far have only yielded disappointing results.

Evidence for the existence of dark matter is inferred from its peculiar gravitational influence on galaxies. Unfortunately, after years of research into potential dark matter particles, scientists have yet to detect any. Many investigations focused on weakly interacting massive particles (WIMPs), which were initially deemed promising candidates for dark matter. Nonetheless, even the most advanced detectors have failed to provide any evidence.

Most detectors designed for WIMPs search for flashes of light generated when a dark matter particle collides with ordinary matter. They hypothesize that these particles are considerably massive, approximately 2 to 10,000 times the mass of a proton. This would ideally align with dark matter’s gravitational effects; however, the possibility exists that WIMPs might be much lighter, a notion that complicates the theory.

Recently, Federica Petricca and her research team from the Max Planck Institute for Physics in Munich, Germany, have explored the search for lighter WIMPs using sugar crystals as an experimental detector under extreme cooling conditions.

Lighter WIMPs should interact more readily with light atoms like hydrogen. However, since pure hydrogen is sparse, it proves to be an ineffective detector. In contrast, sucrose contains 22 hydrogen atoms per molecule, offering a much denser medium for detecting potential interactions.

Petricca and her colleagues meticulously crystallized sucrose from a concentrated syrup over a week, subsequently cooling the material to merely seven thousandths of a degree above absolute zero. Their investigation involved monitoring for dark matter interactions by detecting subtle increases in temperature with an ultra-sensitive thermometer and flashes of light with a photon sensor.

Over the course of 19 hours, while the sugar crystals lit up at levels indicative of larger particles, no weaker signals suggestive of a WIMP interaction were recorded.

According to Carlos Blanco from Pennsylvania State University, the sugar crystals were engineered with exceptional precision to identify subtle interactions from light WIMPs. However, the ability of the experiment to conclusively discount other potential sources of light, such as the common radioactive carbon-14 found in many types of sugar, remains uncertain.