Scientists tested an electron’s response to a magnetic field with extreme accuracy. Why?

Source: The post is based on the article “Scientists tested an electron’s response to a magnetic field with extreme accuracy. Why?” published in The Hindu on 17th February 2023

What is the News?

Physicists have recently made the most precise test yet of the Standard Model of Particles by measuring the magnetic moment of an electron with 0.13 parts per trillion accuracies.

The measurement is 2.2 times more accurate than the previous best, recorded 14 years ago.

What is the Standard Model(SM)?

The Standard Model (SM) is the theory that describes the properties of all subatomic particles, classifies them into different groups and determines how they are affected by three of the four fundamental forces of nature: the strong nuclear force, the weak nuclear force and electromagnetic force (cannot explain gravity).

In the 1960s, physicists used SM to predict the existence of a particle called the Higgs boson; it was finally discovered in 2012. 

Similarly, SM has enabled physicists to successfully predict the existence and properties of dozens of particles and is considered one of the most successful theories in the history of physics.

However, it still fails to explain why the universe has more matter than antimatter, what is dark matter, or what is dark energy. 

Will humans ever find evidence of beyond-Standard Model(SM) forces?

That’s a billion-dollar question. Physicists will test as many of the SM’s predictions as possible to look for a crack in its facade. They already have some clues: SM says neutrinos should be massless, but they’re not.

Physicists have also built detectors to look for different types of hypothetical dark matter particles, sifting through astronomical data to make sense of dark energy, and looking into each other’s calculations. 

Collectively, the community hopes that at least one of these efforts, guided by the principles they discover in their theoretical studies, will reveal a glimpse of a world beyond the Standard Model.