A number of physicists have suggested that dark matter is made from Majorana particles, but Scherrer and Ho have performed detailed calculations that demonstrate that these particles are uniquely suited to possess a rare, donut-shaped type of electromagnetic field called an anapole. This field gives them properties that differ from those of particles that possess the more common fields possessing two poles (north and south, positive and negative) and explains why they are so difficult to detect.
"Most models for dark matter assume that it interacts through exotic forces that we do not encounter in everyday life. Anapole dark matter makes use of ordinary electromagnetism that you learned about in school – the same force that makes magnets stick to your refrigerator or makes a balloon rubbed on your hair stick to the ceiling," said Scherrer. "Further, the model makes very specific predictions about the rate at which it should show up in the vast dark matter detectors that are buried underground all over the world. These predictions show that soon the existence of anapole dark matter should either be discovered or ruled out by these experiments."
This is a comparison of an anapole field (on top) with common electric (in the middle) and magnetic dipoles (beneath). The anapole field is generated by a toroidal electrical current. As a result, the field is confined within the torus, instead of spreading out like the fields generated by conventional electric and magnetic dipoles.
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Ho and Scherrer: Anapole dark matter
Veranderd door confusie, 16 juni 2013 - 11:35