Dark matter is calculated to be about five times more common than ordinary matter — however, it has not been detected directly,media reported. Many different types of experiments are trying to find it, and now CERN is joining the search, testing whether the famous Higgs boson can decay into dark matter.
The Large Hadron Collider (LHC) has discovered the mysteries of the universe by crashing particles together at an alarming rate. In doing so, new, exotic particles are often created, giving scientists a brief opportunity to study things that are almost impossible to encounter naturally.
One of the LHC’s most ground-breaking discoveries was the Higgs boson discovered in 2012. This long-assumed particle is the last piece of the puzzle in the standard model of particle physics, and it is thought to have created other methods for the mass of elementary particles.
Since the discovery of the Higgs boson, scientists have used it to explore the physics mysteries of other particles. The Higgs boson quickly decays into other particles, and some of them may not be detected directly by the device.
In this case, however, non-testing is more exciting than detection. Because certain types of particles do not interact well with ordinary matter, if the Higgs boson produces such particles, they will drift away and ignore the presence of the collider wall. The scientists will then notice the lack of energy in the wreckage and be able to infer something about the “invisible” particles.
Only invisible decay products conform to the standard model — if the Higgs boson decays into four neutrinos — but this is highly unlikely, with a probability of only 0.1%.
One of the invisible particles may be dark matter. It is said that this strange material penetrates into the universe and effectively brings it together, yet it is still very elusive. Its gravitational influence is obvious, but it does not seem to reflect or emit any kind of light.
Given the role of the Higgs boson in “giving” the particle mass and the fact that dark matter can only be detected by its mass, the two particles should interact. So in the new study, scientists working with CERN’s ATLAS began to examine whether the Higgs boson was decaying into dark matter.
The team examined the entire data set for the LHC’s second run, which took place between 2015 and 2018. There have been about 100 trillion collisions in those three years. In all of these data, the researchers found that invisible particle events did not exceed the background value during the known process of the standard model. In response, the team was able to reduce the upper limit of the frequency at which the Higgs boson decayed into invisible particles — no more than 13 percent. This sounds a lot more likely, but this is based on previous models, which suggested that this could happen as much as 30% more frequently.
The researchers say that although they have found no signs of dark matter this time, the work could help limit its properties. Between this experiment and many others trying to find it, dark matter may have no hiding place. Or humans are just getting closer to realizing that it doesn’t exist, and the models now used need to be adjusted. In any case, the search for it continues.