Understanding and refining the gyromagnetic factor, or “g factor,” is more than a theoretical pursuit—it directly impacts how we improve real-world tools like MRI machines, atomic clocks, and quantum sensors. These technologies depend on precisely measuring how tiny particles interact with magnetic fields, and even slight improvements in that understanding can lead to sharper images, more accurate timekeeping, and better sensors.
The g factor is a number that helps describe how particles like electrons respond to magnetic fields. It tells us how the electron’s own magnetic strength relates to the way it spins. In earlier work from nearly a century ago, physicist Paul Dirac predicted that this value would be exactly two. But later discoveries in modern physics showed that the number is slightly more than two. This small difference, known as the “anomalous magnetic moment,” which means a slight but important shift in the expected magnetic behavior, has become a useful clue for testing our current theories about how the universe works.
Professor Jing-Ling Chen, Xing-Yan Fan, and Xiang-Ru Xie from Nankai University have introduced a bold new idea that could change the way scientists think about this g factor. Their research, published in the scientific journal Results in Physics, offers a new explanation for why the g factor might change. The concept, which they call “electron-braidon mixing,” shows that even without using advanced quantum field theories—which describe how particles interact at the smallest scales—the g factor of an electron could still be altered in noticeable ways.
At the center of this idea is something called a “braidon,” a made-up concept based on braiding patterns—similar to how threads are woven together. These patterns, known as braid relations, are used in some areas of physics to explain how particles might behave in special ways, especially in systems where their arrangement matters. Professor Chen’s team found that the main equation used to describe an electron’s energy, called the Dirac Hamiltonian, could be treated as just one part of a larger system. In this bigger picture, two more versions of this equation naturally appear, each offering a slightly different view of the same electron. By combining the regular electron with these alternative forms, they created a mixed version of the electron that behaves differently in a magnetic field.
This combination depends on a couple of adjustable settings, referred to as mixing angles. These are values that determine how much of each version of the electron is present in the mix, like blending colors in different proportions. The scientists showed that by changing these angles, the g factor could also change. In one example they examined, the g factor shifts based on a simple mathematical link between these angles and how fast the electron is moving compared to its mass. “Our results shed new light on the problem of the anomalous magnetic moments of leptons,” Professor Chen noted. Leptons are a family of particles that includes electrons, muons, and tau particles.
Importantly, this process of mixing doesn’t create any new particles. It simply changes the way the existing electron is described using mathematical tools. “Dirac’s braidon is not a new particle. Namely, Dirac’s braidon is still an electron, but a unitary-transformed ‘electron,’” Professor Chen explained. A unitary transformation is a mathematical method that changes how something is represented without changing its core physical properties. In other words, the braidon is just another way to represent the same electron, not a different type of matter.
This method could also be applied to other heavier particles that are similar to electrons, such as muons and tau particles. These particles are more affected by changes in the g factor because of their greater weight. By using the same equations, scientists could figure out what kind of mixing might explain the differences seen in experiments. This gives physicists a new tool to understand strange results.
Even though this idea is still theoretical—meaning it has not yet been confirmed by experiments—it offers an exciting possibility for real-world testing. Scientists could look for signs that the g factor changes in new ways, not because of outside forces or new particles, but because of how the electron is mixed with its alternative versions. If this proves true, it could help clarify the results of past experiments and offer better guidance for future ones. Professor Chen suggest more work is needed to understand the deeper symmetry rules—basic patterns that help explain physical laws—behind this mixing. For now, Professor Chen believes this idea “paves an enticing way for physicists to find ‘new physics,'” even using well-established ideas.
Journal Reference
Chen J.-L., Fan X.-Y., Xie X.-R. “A possible mechanism to alter gyromagnetic factor.” Results in Physics, 2025; 69: 108125. DOI: https://doi.org/10.1016/j.rinp.2025.108125
About the Author
Jing-Ling Chen is a professor of physics at Nankai University. He got his bachelor’s degree (1994), master’s degree (1997) and doctor’s degree (2000) in Nankai University, P. R. China. He has been a post-doc at Beijing institute of apply physics (2000-2002) and a research fellow at National University of Singapore (2002-2005), respectively. His research interest is quantum physics and quantum information, especially in quantum fundamental problems, such as EPR paradox, quantum entanglement, EPR steering, Bell’s nonlocality and quantum contextuality. Due to his contribution in quantum foundations, he has won the Paul Ehrenfest Best Paper Award for Quantum Foundations (2021). Recently, he has made some original explorations on spin, such as proposing the spin vector potential, presenting the spin-type Aharonov-Bohm effect, and predicting the spin angular-momentum wave.
