According to the Big Bang Theory, the Universe at one time existed only as energy during that explosion, and only after the Universe cooled did particles start to form. Based on our current understanding of particle physics though, such cooling should have resulted in equal parts matter and antimatter, but this is clearly not what happened. In an effort to understand why we exist, researchers at Harvard University have made the most precise measurement of the magnetism of the antiproton.
When taught about antimatter, most people are told that it is identical to normal matter, but with opposite charges, so an antiproton has a negative charge and positrons are positive. Particle physicists are not certain about this though, and any difference between a particle and its antiparticles, such as the magnitude of their charges, would be very impactful on the science. For example, it could suggest that antimatter more readily decays into other fundamental particles than normal matter, hence explaining why more normal matter exists.
To make their measurements, the researchers had to capture a proton and antiproton, and then measure their oscillations to determine the strength of their magnetism. The results were 1000 times more accurate than the previous best for protons, and 680 times more accurate for antiprotons, and both results fit current theory. Perhaps in the future, after the researchers have improved their accuracy by another factor of 1000 or more, the results will start to deviate from theory.
Source: Harvard University