Myon G-2: Precise measurements fuel hope for new physics!

Myon G-2: Precise measurements fuel hope for new physics!

The Myon G-2 collaboration announced its third and last publication on the measurement of the anomal magnetic moment of the Myon on June 3, 2025. The results show a remarkable improvement in accuracy to 127 parts in one billion (ppb) and confirm the results of the previous measurements from 2021 and 2023. This research team, to which the only German group under the direction of Prof. Dr. Martin Fertl from the Johannes Gutenberg University Mainz has heard a year of intensive work in the Fermi National Accelerator Laboratory (Fermilab) on the Myon Campus.

With a specific value for the anomal magnetic moment of Aµ = (G-2)/2 = 0.001 165 920 705 ± 0,000 000 148, the collaboration presents the most precise result that was ever achieved on this topic. The measurement is based on data from over 72% of the a total of 308 billion myons analyzed during a six -year experiment that started in 2018 and ended on July 9, 2023.

A next step in particle physics

The anomal magnetic moment of the myon is more than just a theoretical number. Through these measurements, physicists hope for new insights into the dark matter of the universe. Dyscalated matter makes a larger part of the universe than ordinary matter, but its composition remains largely unknown. The myon, with a mass of 200 times that of the electron, has an anomal magnetic moment that has deviations from the theoretical value-a deviation caused by vacuum fluctuations. These fluctuations could not only influence the behavior of myons, but also indicate unknown particles that may be hidden in dark matter.

The way to these results was not without challenges. During the experiment on the fermilab, distortions were excluded by careful time measurements. In order to ensure the neutrality of the scientists, the timepiece of the experiment was postponed by a random number, which later led to falcons of data that could only be corrected after the analysis was completed. Jessica Esquivel, a member of the Muon-G-2 team, noted that the publication of the results triggered mixed feelings of ecstasy and pessimism.

Future view and theoretical developments

The Myon G-2 collaboration comprised almost 180 scientists from 37 institutions in seven countries. Scholarships for students and the collaboration of physicists from different fields underline the international dimension and the interdisciplinary character of this project. These efforts result in new theoretical predictions for the anomal magnetic moment based on grid QCD invoices and bring the values ​​into harmony with current experiments.

For the future, further experiments are being planned. A new experiment in Japan should provide additional data in the early 2030s, although a lower precision is expected. These projects could raise light on fundamental questions of physics and initiate new theories, especially with regard to the standard model of particle physics and the search for dark matter.

Overall, the Myon G-2 study is a significant progress. It not only underpins established physical principles, but could also open the entry into new areas of research. The results were submitted for the publication in the journal Physical Review Letters and set a new standard for future measurements in particle physics.