New evidence suggests the Standard Model is Incomplete.

by James Neil 18/04/2021

Last month scientists announced that the longstanding theory that governs the world of particle physics appears to be incomplete.

The standard Model | image coutesy of CERN

The standard model is a sort of periodic table of subatomic particles. It allows us to determine what particles might exist and the rules that govern their interactions and is fundamental to our understanding of the subatomic world. The model, amongst other things, suggests that there are two types of Subatomic particles, Quarks, and leptons. Quarks act as the building blocks of subatomic particles. One example is the proton which is formed from two up Quarks and one down Quark (Quarks tend to have strange names). Leptons are particles like electrons and are much larger than quarks with larger electrical charges. The standard model also tells us how these particles might interact for example decay in which a particle transforms into another often releasing energy as a result.

Scientists at one of CERNS detectors, LHCb, have been investigating a flavour of Quark known as a Beauty Quark and its decay. According to the standard model, a beauty quark can decay into either an electron, which is a small, charged particle we see in atoms or into a Muon which is a much heavier particle. This decay should occur with an equal probability of the Quark forming into an electron or muon.

What was found after eight years of study was that the Beauty Quark tended to decay into an electron. Whilst this seemingly intriguing quirk of the Beauty Quark seems inconsequential, it has much wider implication in the world of particle Physics. It suggests that the standard model which has been used for the past 50 years of Particle physics research is incomplete.

So far scientists suggest that this discovery may mean the existence of a formally unknown particle known as the 'Leptoquark', however, this theory won't be able to be confirmed by CERN scientists until at 2022 as the detector is scheduled for maintenance and improvement for the rest of the year.