Today at CERN, the Large Hadron Collider collaborations ATLAS and CMS jointly announced the discovery of the Higgs boson transforming into bottom quarks as it decays. This is predicted to be the most common way for Higgs bosons to decay, yet was a difficult signal to isolate because background processes closely mimic the subtle signal. This new discovery is a big step forward in the quest to understand how the Higgs enables fundamental particles to acquire mass.

After several years of refining their techniques and gradually incorporating more data, both experiments finally saw evidence of the Higgs decaying to bottom quarks that exceeds the 5-sigma threshold of statistical significance typically required to claim a discovery. Both teams found their results were consistent with predictions based on the Standard Model.

“The Higgs boson is an integral component of our universe and theorized to give all fundamental particles their mass,” says Patty McBride, distinguished scientist at the US Department of Energy’s Fermi National Accelerator Laboratory and recently elected a deputy spokesperson of the CMS experiment. “But we haven’t yet confirmed exactly how this field interacts—or even if it interacts—with all the particles we know about, or if it interacts with dark matter particles, which remain to be detected.”

Higgs bosons are produced in only roughly one out of a billion LHC collisions and live only a tiny fraction of a second before their energy is converted into a cascade of other particles. Because it’s impossible to see Higgs bosons directly, scientists use these secondary particle decay products to study the Higgs’ properties. Since its discovery in 2012, scientists have been able to identify only about 30 percent of all the predicted Higgs boson decays. According to Viviana Cavaliere, a physicist at Brookhaven National Laboratory who works on the ATLAS experiment, finding the Higgs boson decaying into bottom quarks has been priority no. 1 for the last several years because of its large decay rate.

“Theory predicts that 60 percent of Higgs bosons decay into bottom quarks,” says Cavaliere, who is also using this process to search for new physics. “Finding and understanding this channel is critical because it opens up the possibility for us to examine the behavior of the Higgs, such as whether it could interact with new, undiscovered particles.”

The Higgs field is theorized to interact with all massive particles in the Standard Model, the best theory scientists have to explain the behavior of subatomic particles. But many scientists suspect that the Higgs could also interact with massive particles outside the Standard Model, such as dark matter. By finding and mapping the Higgs bosons’ interactions with known particles, scientists can simultaneously probe for new phenomena.

“A fraction of Higgs bosons could be producing dark matter particles as part of their decay,” says Giacinto Piacquadio, a physicist at Stony Brook University who co-led the Higgs-to-bottom-quarks analysis group. “Because the decay of the Higgs boson to bottom quarks is so common, we can use it to put constraints on potentially invisible decays as well as use it to probe for new physics directly.”