Errors in the recent dark-matter search experiment may open up new avenues for particle physics, but it is entirely possible that these are just the anomalies seen in these ultra-precise experiments.
An underground Xenon tank in Italy could have just discovered a new kind of particle, born in the center of the Sun. If this had really happened, it could upset the laws of physics that have existed for more than 50 years.
The researchers created an underground container to study dark matter, which is difficult to grasp but according to modern astronomy theories, it accounts for 85% of the universe.
Scientists know dark matter exists because it is possible to measure the gravity of its impact on distant galaxies, but they have never been able to directly detect it before. So far, the most feasible predictions of dark matter suggest that it includes clouds of subatomic particles left over from the Big Bang and are collectively known as WIMP particles .
Experiment Xenon1T: On the left is a container with a poster showing what is inside, on the right is a 3-story high-rise building of the researchers.
That's why the Xenon1T experiment is being conducted by an international team of scientists at the Gran Sasso National Laboratory in Italy. They want to find direct evidence to prove the existence of this fundamental type of matter in the universe.
This experiment involved the use of a cylindrical container filled with 3.2 tons of liquid Xenon, cooled to -95 ° C (minus 95 degrees Celsius). This container is placed deep underground to ensure the radiation waves interfere with this experiment. According to Dr. Elena Aprile of Columbia University, who led the experiment, Xenon is by far the most sensitive substance to detect and identify dark matter.
Xenon container before being installed.
The container is also connected to optical actuators and many other sensors to detect the rare interactions between subatomic particles of dark matter and Xenon atoms. Theoretically, these interactions will produce small light rays with electrons.
In the latest experiment of this experiment, the researchers initially expected the machine to detect about 232 interactions, based on known particles. But instead, they discovered 285 interactions - 53 more than expected.
Furthermore, the energy emitted from these unintended interactions corresponds to the predicted energy levels of a previously unseen range of particles, called solar axions . The particle has been theoretically predicted by its physicists but has never been found.
" The theoretical particle that seems to fit this Xenon1T data seems too heavy for dark matter, but could be produced by the Sun. " Sean Caroll, a physicist at the California Institute of Technology told Business Insider. " If this is true, it will be of tremendous importance - this could be a discovery that will lead to the Nobel Prize ."
Photomultiplier tubes are used to detect light rays from the Xenon1T experiment.
But these unexpected interactions can also be just anomalies, which are common in high-sensitivity physics experiments like Xenon1T.
The latest discovery of elementary particles has been around since the 1970s. That was when the Standard Model was established - a set of known rules for particle physics, to describe all the elementary particles discovered by scientists and how they interacted. interact with other particles.
That's why the newly discovered particle of the Xenon1T experiment is so important. If the experiment results are correct, it will prove the existence of a new particle, outside the Standard Model, which has existed for nearly half a century.
" That would be the first solid finding of something outside the Standard Model ." Aaron Manalaysay, a dark-matter physicist at Lawrence Berkeley National Laboratory, said. " This is like a holy grail for particle physics ."
The refrigeration unit is suspended from a support cylinder in the tank of the Xenon1T experiment.
Another possible explanation for the unintended interactions of the experiment is that neutrinos - a non-charged subatomic particle - can also cause these interactions.
This can also redefine known physical laws, as this means that neutrino particles also have a larger magnetic field than the Standard Model predicts. "This may indicate new physical rules outside the Standard Model," said physicist Manalaysay .
It is also possible that the findings in the Xenon1T experiment did not occur - although this was unlikely. The researchers calculated that only 2 of the approximately 10,000 events detected were due to random fluctuations.
Gran Sasso Laboratory is the largest underground laboratory in the world, when it is located at a depth of 1.3km of the ground.
However, these signals may come from other ordinary particles - an unattractive explanation for possibilities such as axions or neutrinos. Unexpected events may come from collisions with small amounts of tridium, a radioactive isotope of hydrogen, which decays right inside the container. According to Manalaysay, the Argon isotopes also produce the same effect.
" It's not too much. Only about a few atoms, " he said. Some atoms may be too much for a super precision science such as particle physics.
Therefore, a new version of the Xenon experiment is being implemented in the US and Europe, to help researchers explore these unpredictable events and determine which particles cause collisions. this. That is why new experiments will be conducted on a larger scale and are significantly more sensitive than previous experiments.
While the Xenon1T experiment only discovered 53 inexplicable interactions, according to Manalaysay, its successor, the LUX-ZEPLIN experiment can detect up to 800 interactions. The current outbreak of corona virus is disrupting the preparation of this experiment, but new experiments are likely to work and produce "next year" results.