Physicists at the Lawrence Berkeley National Laboratory in the United States have found that the mysterious high-energy radiation emitted from the vicinity of a group of neutron stars may indicate the existence of axions – not yet discovered particles within the framework of New Physics, which have been searched for since 1977. It is assumed that special types of axions form dark matter. This is reported in an article published in the journal Physical Review Letters. The research is summarized in a press release on Phys.org.
It is believed that axions can form in the core of neutron stars and transform into photons in the presence of a powerful magnetic field. To detect the electromagnetic radiation associated with axions, it is necessary to find stars that do not emit radiation at different wavelengths that can mask the desired signal. Such objects include neutron stars belonging to the Magnificent Seven group and emitting only X-ray and ultraviolet radiation. They are located at a distance of 200-500 parsecs from the Earth.
Researchers ruled out a scenario according to which the excess X-rays produced by the Magnificent Seven are actually emitted by other, more distant objects. These sources would be found in datasets from the XMM-Newton and Chandra X-ray space telescopes.
According to the findings of the scientists, the additional X-rays probably originate from axions hitting an extremely strong electromagnetic field, which is billions of times stronger than the magnetic fields that can be created on Earth. The axions themselves resemble neutrinos in their properties, since both have insignificant masses and rarely and weakly interact with matter.
Axion is currently viewed as the most promising candidate for dark matter particles, as another hypothetical candidate, the massive WIMP particle ((WIMP)), has gone unnoticed in experiments aimed at detecting it. In addition, there may be a whole family of axion-like particles that form dark matter, as suggested by string theory. If axions are found, it will prove that there is a whole new area of physics outside the Standard Model describing the properties of all known particles.