For the first time, the researchers cooled antimatter to near absolute zero by trapping it in a magnetic trap and exploding it with concentrated laser light.
This method allowed Canadian scientists working in the CERN Anti-Hydrogen Laser Physics Apparatus (ALPHA) experiment to cool antimatter to temperatures as low as one-twentieth of a degree above absolute zero, making it more than 3,000 times colder than the lowest recorded temperature. in Antarctica.
In theory, this supercooled antimatter could help uncover some of the universe’s greatest secrets, such as how antimatter is affected. gravity and whether some of the fundamental theoretical symmetries proposed by physics are real.
Antimatter ethereal opposite of the usual matter… The theory of antimatter was first put forward by Paul Dirac in 1928 and was discovered just four years later. Antimatter particles are identical to their matter counterparts, except for their specular physical properties: an electron has a negative charge, and its antimatter counterpart, a positron, has a positive charge. The reason we don’t encounter antimatter as often as we do with ordinary matter is because the two annihilate each other on contact, making it extremely difficult to store and study antimatter in the material world.
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However, thanks to a number of ingenious technical advances, the researchers were able to do this. After accelerating ordinary particles of matter to near light speed and then colliding, the team was able to create antiparticles. The team then controlled and slowed down the moving antiparticles using extremely strong magnetic and electric fields. Finally, the team held clouds of positrons and antiprotons within a magnetic field until they combined to form antihydrogen. At this stage, the researchers cooled the antihydrogen cloud by detonating it with a laser.
But how do you cool something with a laser? Particle movement creates heat. So, the trick is that the photons (light particles) in the laser beam move in the opposite direction to the moving antimatter particles. Since photons have their own momentum, their absorption by antihydrogen when traveling in the opposite direction can actually slow down the antihydrogen. But light can only interact with antimatter if it is tuned to very specific wavelengths at which light can be absorbed by an antiatom.
“Think of antihydrogen as a curling stone and photons as small hockey pucks,” said Makoto Fujiwara, spokesman for the Canadian ALPHA team. “We tried to slow down the curling by shooting pucks at him only when he was moving towards us. It’s really tricky on an atomic scale, so we’re using the Doppler effect to tune the washers so that they can only interact with the rock when it’s moving towards us, not away from us and sitting at rest. “
The Doppler effect – when the observed wavelength of light shrinks or lengthens as the light source moves towards or away from the observer – allowed scientists to very finely tune the wavelength of photons so that they are absorbed by antihydrogen particles only if they approached them, slowing down movement of antihydrogen particles.
Cooled antimatter will help researchers make much more accurate measurements, opening up a series of experiments to explore some of the deepest mysteries of physics. For example, by dropping a cloud of antimatter a certain distance, they can test if it reacts to gravity in the same way as ordinary matter. Or, by shining a light on this cloud, they can compare the energy levels of antihydrogen to the energy levels of ordinary matter with unprecedented precision.
Fujiwara is particularly happy to use his cooled antimatter in an interferometer experiment.
“We want to get one antiatom in a vacuum and split it into a quantum superposition so that it creates an interference pattern with itself,” Fujiwara told Live Science. Quantum superposition allows very small particles, such as antihydrogen, to appear in multiple locations at the same time. Because quantum particles behave like a particle and a wave, they can interfere with themselves, creating a pattern of peaks and troughs, much like waves from the sea travel through breakers.
“So we can really study exactly how it interacts with other forces and what its general properties are.”
The team also proposed sending antiatoms into free space, as well as combining them to produce the world’s first antimatter molecules.
The researchers’ findings are published on March 31 in the journal. Nature…
Originally published on Live Science