Scientists managed to observe one of the rarest physics events ever while hunting for dark matter. Researchers with the XENON Collaboration were busy hunting for signs of one of the universe’s biggest mysteries when they observed the radioactive decay of a substance known as xenon-124, an event that has eluded scientists for decades.
Scientists just witnessed a rare physics event
Xenon is a colorless and odorless noble gas that is found in tiny amounts throughout our atmosphere. Despite the little we know about it; scientists have never managed to observe the radioactive decay of an isotope within the element. At least until now. They published their findings on the rare physics event in the journal Nature.
The finding is especially important because scientists previously believed this isotope was completely stable. With this new observation, we know that it does indeed have a half-life. The event occurs when two protons within a nucleus simultaneously convert into neutrons by absorbing two electrons from one of the atomic shells. This causes the emission of two electron neutrinos.
When that happens, the rare physics event they just observed occurs and a predictable cascade of X-rays and Auger electrons shoots out after.
How long is xenon-124’s half-life?
But what exactly does this rare physics event tell us? Well, for starters, it proves that xenon-124 is not completely stable. It does decay. We also were able to estimate the half-life of xenon-124. Based on the data the scientists observed, they believe the timescale measures in at around 18 sextillion years.
That’s roughly 1 trillion times the age of our universe, the team of researchers says. Additionally, it’s the slowest process that we have ever measured directly. The rare physics event was observed during a test attempting to observe dark matter, which makes up 85 percent of the mass in the universe.
The researchers were hunting for dark matter using the XENON1T experiment. The experiment basically relies on the scientists exposing their detector to a massive amount of xenon atoms, roughly 3.2 tons of liquid xenon. It’s this massive exposure that allowed them to detect the rare event itself.
Unfortunately, while we have learned more about xenon-124, we haven’t actually managed to observe dark matter just yet. Scientists have discovered some possible candidates for dark matter, though. For now, we’ll need to wait on the scientists to kick up more experiments with the XENONnT detector.