Sun Sheds Light on Puzzling Matter-Antimatter Asymmetry Mystery

There's a puzzling strong asymmetry between matter and antimatter that scientists have found difficult to explain. Now, the sun may shed some light on the matter. Researchers have discovered antimatter in solar flares via microwave and magnetic-field data, which could allow them to better understand the asymmetry.

Antiparticles can be created and then detected with costly and complex particle-accelerator experiments. Yet otherwise, these antiparticles are very difficult to study. The fact that they could be naturally located in the midst of solar flares, though, could allow researchers to better understand antimatter and use the sun as a laboratory.

In this particular study, researchers reported the first remote detection of relativistic antiparticles, known as positrons, produced in nuclear interactions of accelerated ions in solar flares. The fact that these particles are created in solar flares is not a surprise. However, the fact that they were actually detected is a huge leap forward for future studies.

Detecting these particles wasn't easy. Electrons and their antiparticles, positrons, have the same physical behavior except that electrons have a negative charge while positrons have a positive one. This charge difference causes positrons to emit the opposite sense of circularly polarized radio emissions, which is what the researchers used to distinguish them. This method required knowledge of the magnetic field direction in the solar flare, which the researchers collected from NASA's Solar and Heliospheric Observatory. In the end, they found that the radio emission from the flare was polarized in the normal sense at the lower frequency where the effect of positrons is expected to be small, but reversed to the opposite sense at the same location, although at the higher frequency where positrons can dominate.

So what kind of implications do these findings have? Researchers could gain valuable knowledge through remote detection of relativistic antiparticles at the sun and, potentially, other astrophysical objects by means of radio-telescope observations. The ability to detect these antiparticles in an astrophysical source promises to enhance scientists' understanding of the basic structure of matter and high-energy processes, such as solar flares.