Everything changes, and nothing stays the same.
Even in physics.
Earlier this year, the Large Hadron Collider (LHC) released new and exciting evidence that hinted at a new force in physics. Now, after months of deliberation, CERN’s colossal particle collider has taken one step closer to confirming this world-historical finding, according to a recent study shared on a preprint server.
While the new results of the recent study still need to complete the process of peer review, we could be nearing the end of the Standard Model as we know it. So say your goodbyes.
The incompleteness of the Standard Model
The Standard Model is undeniably the most successful scientific theory ever created, but it’s also incomplete. It describes three of the four fundamental forces in the natural universe: the strong and weak forces, and the electromagnetic force. Gravity is beyond the bounds of the Standard Model, the latter of which also offers no explanation for dark matter that we know overwhelmingly dominates the cosmos. The Standard Model also has nothing to say about the Big Bang, the unimaginably violent explosion of everything from an infinitely dense point that gave birth to the universe.
The majority of physicists are fairly certain that more cosmic forces await our discovery, and the ongoing investigation of fundamental particles called quarks has become an especially appealing means of uncovering new clues about what lies beyond the Standard Model. Beauty quarks, which are at times called bottom quarks, are fundamental particles that also comprise larger ones. Quarks come in six types, called up, down, charm, strange, beauty/bottom, and truth/top. The first two (up and down) quarks compose neutrons and protons that in turn serve as building blocks to the atomic nucleus. On the other hand, beauty quarks are unstable, and live for an average of roughly 1.5 trillionths of a second before subsequently decaying into different particles.
Decay into muons is slightly less frequent than decay into electrons
And the way these beauty quarks decay can be strongly affected by the potential existence of other forces, or particles, that await our discovery. When beauty quarks decay, they change into a pair of lighter particles like electrons, via the weak force. And one way a new force of nature could reveal itself to us is via a subtle change in the frequency at which beauty quarks decay into varying kinds of particles. The earlier, March paper on the same phenomenon looked at data from an LHCb experiment (the “b” is for “beauty”), which is one of four colossal particle detectors that record the results of the extremely high-energy collisions generated by the LHC.
The March paper found that beauty quarks were decaying into electrons, in addition to their heavier cousins, called muons, at different rates. This was unexpected since, according to the classic Standard Model, the muon is nearly identical to the electron, except for being roughly 200 times heavier. This means that, when a beauty quark decays into lower-energy particles, it should do so into electrons or muons at similar frequencies. But the results showed that decay into a muon occurred roughly 85% as frequently as decay into electrons. This latest study brings us one step closer to uncovering a new force of nature, but until the chance of error for this phenomenon moves from a one in 1,000 chance (“three sigma”) to a “five sigma” probability of statistical wobble, these findings will remain a very promising possibility.