Scientists near the city of Chicago in the United States suggest they may be on the brink of discovering a new force of nature. If confirmed, this would constitute the fifth fundamental force that determines how all objects and particles in the universe interact with each other.
Researchers have obtained new evidence indicating that subatomic particles called muons do not behave as predicted by the current theory of subatomic physics.
Scientists believe that an unknown force could be at play on muons.
Further data is needed to confirm these findings, but if verified, it could mark the beginning of a revolution in physics.
In our everyday lives, all the forces we constantly experience can currently be reduced to four categories: gravity, electromagnetism, strong nuclear force, and weak nuclear force. These four fundamental forces determine how all objects and particles in the universe interact with each other.
The new findings were obtained at a U.S. particle accelerator facility called Fermilab, building upon results that the Fermilab team first proposed the possibility of a fifth fundamental force back in 2021.
Dr. Brendan Casey, a senior scientist at Fermilab, states that the research team has since collected more data and significantly reduced the uncertainty in their measurements.
Casey says, “We’re really exploring a new region. [Measurements are] being done with a precision that’s never been done before.”
In the experiment, known by a memorable name like ‘g minus 2 (g-2)’, researchers accelerate subatomic particles called muons around a 15-meter diameter ring at nearly the speed of light, circling the ring approximately a thousand times.
Researchers have obtained data suggesting that muons may be behaving in a manner that cannot be explained by the current theory known as the Standard Model, possibly due to the influence of a new force of nature.
Although the data is compelling, the Fermilab team does not yet possess conclusive evidence.
While they had hoped to achieve this by now, uncertainties in the Standard Model about how much wobbling should occur in muons have increased due to developments in theoretical physics.
This has shifted the target criteria for experimental physicists.
The researchers believe they will have the necessary data and that the theoretical uncertainties will decrease enough within the next two years for them to reach their goals.
A competing team at the Large Hadron Collider (LHC) in Europe hopes to achieve this milestone earlier.
Dr. Mitesh Patel from Imperial College London, one of thousands of physicists striving to uncover flaws in the Standard Model at the LHC, states in an interview with BBC News that those who discover experimental results conflicting with the Standard Model’s predictions will make one of the greatest discoveries in the history of physics.
“Measuring behaviors that deviate from the predictions of the Standard Model is the expected goal of particle physics. As the Model has stood the test of all experimental tests for over 50 years, it will act as the spark for a revolution in our understanding.”
Fermilab asserts that their next results will consist of “ultimate data” that could reveal new particles or forces between theory and experiment.
The Standard Model
The Standard Model is a theoretical framework in particle physics that describes the fundamental particles and their interactions, serving as one of the cornerstones for understanding and explaining the smallest building blocks of the universe. Here are the key features of the Standard Model:
- Fundamental Particles: The Standard Model defines the basic constituents of all matter and energy in the universe. These fundamental particles fall into two categories: fermions (leptons and quarks) and bosons.
- Fermions: Leptons (such as electrons and neutrinos) and quarks (building blocks of particles like protons and neutrons) are called fermions. These particles make up matter, with quarks in particular combining under the influence of the strong nuclear force to form nuclear particles.
- Bosons: Bosons are carrier particles for forces. Photons transmit the electromagnetic force, W and Z bosons carry the weak nuclear force, and gluons mediate the strong nuclear force. The Higgs boson explains a mechanism for particles acquiring mass.
- Unification of Forces: The Standard Model describes the fundamental forces as the electromagnetic force, the weak nuclear force, and the strong nuclear force. It unifies the electromagnetic and weak nuclear forces into the electroweak theory but does not include the gravitational force.
- Quantum Field Theory: The Standard Model is built on the foundation of quantum field theory, explaining how particles and forces interact based on quantum mechanical principles.
- Discoveries and Confirmations: The Standard Model has been confirmed through numerous experiments and observations. Experiments conducted at high-energy particle accelerators like the Large Hadron Collider (LHC) have supported its predictions, including the discovery of the Higgs boson.
However, the Standard Model does not fully explain certain phenomena observed in the universe, particularly issues like dark matter and dark energy. As a result, scientists continue their efforts to extend the Standard Model or develop new theories to account for these gaps.