One of the central puzzles of particle physics is to figure out which particles (or particles!) Are dark matter – the form of matter that accounts for 85 percent of the mass in the known universe.
Some physicists believe that finding a hypothetical particle known as "axion" could lead to a better understanding of dark matter and then hunt for it. An American physics team has recently designed a donut-shaped basketball and tested apparatus that can look for it.
It has been thought that axions are detectable by an unusual type of neutron star known as "magnetar". These small, outbursting stars create some of the strongest magnetic fields in the universe. Due to their huge magnetic force, axions would be converted into radio waves in the presence of the magnetar ̵
This strange cosmic phenomenon inspired theoretical physicists to create the impressively named ABRACADABRA experiment (The full name is "A broadband / resonant approach to cosmic axis detection" with a B-field amplifying ring apparatus) Theoreticians deserve a round of applause for this backcronym, which consists of a donut (or "toroid") shaped device dangling in a freezer just above absolute zero and set to create its own magnetic field.
Axion ions are present, the magnetic field in the center of the donut could reveal them.
"That was the elegant thing about this experiment," said Lindley Winslow, chief investigator of the project, in a press release. "Technically, if you've seen this magnetic field it could just be the axion because of the particular geometry they were thinking of. "
The first The ABRACADABRA run took place in July and August 2018, looking for evidence that axions interacted with the device.
However, the team did not detect any signs of the "ghostly" particle. While this seems to be bad news for Axion enthusiasts, the experiment does not end there. The magnetic field – the energy – that Axion generates is likely to be so small that it could not detect this run as it only looked like a very narrow, narrow area. As with finding a lost remote control in the house, researchers have just looked under the couch – they can still look under the pillows, in the bedroom and behind the TV.
"This is the first time anyone has considered this Axion directly," says Winslow. "We are pleased that we can now say:" We have a way here, and we know how to do it better!
The study was published on March 28 in the journal Physical Review Letters.