Back in June of 2020, a large group of physicists had reported flashes of light that match with those expected from a type of dark matter called dark bosons. Now, one of two other teams conducting research into dark matter claims to have also found hints consistent with the elusive particle.
The dark-matter boson – predicted to interact weakly with ordinary matter – has long been hailed as one of the main candidates for explaining astrophysical observations without directly contradicting the results of previous experiments.
It’s been theorised that dark bosons would be “virtually” exchanged between an atom’s electrons and neutrons, thereby inducing tiny forces in their midst, and changing the atom’s transition frequencies.
Both teams engaged in the search for dark-matter bosons conducted a series of identical experiments designed to measure the so-called isotopic shift, or the minute differences between the atomic spectra exhibited by isotopes of the same element.
The first team, led by Vladan Vuletić of the Massachusetts Institute of Technology (MIT) measured the shift between five isotopes of the chemical element ytterbium, while the second team, led by Michael Drewsen of Aarhus University, Denmark, measured the shift between five calcium isotopes.
In line with predictions of the standard model, Drewsen’s team found the isotope shifts to line up on a King-plot – a common method for representing the phenomenon – just as expected. In contrast, however, the Vuletić team reported a deviation from linearity with a statistical significance of 3 sigma.
According to the researchers themselves, their findings are, in fact, consistent with a leading correction to the standard model. And yet, if further studies back them up, this could be a sign of the existence of dark bosons.