After identifying the Higgs boson, scientists at the Large Hadron Collider have targeted an elusive target.
Around us are dark matter and dark energy ̵
The dark world makes more than 95 percent of the universe scientists only know that it exists of their effects – as a poltergeist can only be seen if he pushes something off the shelf. For example, we know that dark matter exists because gravity can affect it – it helps keep our galaxies from flying apart.
Theorists believe that there is a certain type of dark particle that only occasionally interacts with normal matter. It would be heavier and longer than other known particles with a lifetime of up to a tenth of a second. Several times in a decade, the researchers believe, this particle can become entangled in the collisions of protons that the LHC constantly generates and measures.
"One particularly interesting possibility is that these long-lived dark particles are coupled to the LHC Higgs boson in some ways – that the Higgs is actually a portal to the dark world," Wang said, referring to the last particle that The physicists found in the last year on the LHC theory of the functioning of the universe. "That's possible." The Higgs could actually fall into these long-lived particles.
The only problem is sorting these events off the rest: the 27-kilometer-long LHC has more than a billion collisions per second, and each of them emits subatomic chaff in all directions.
Wang, UChicago Postdoctoral colleague Jia Liu and Fermilab scientist Zhen Liu (now at the University of California, Maryland) suggested a new kind of search by exploiting a certain aspect of such a dark particle. "If it's that hard, it costs Producing energy, therefore, the momentum would not be great – it would move slower than the speed of light, "said Liu, the first author of the study.
That time delay would set in. Apart from the rest of the normal particles, scientists would just have to adjust the system to look for particles that are produced and then decay slightly more slowly than anything else.
The difference is on the order of e in nanosecond – a billionth of a second or less. However, the LHC already has detectors that can tell the difference. a recent study that gathered data from the last run and concluded that the method should work, and the detectors will become even more sensitive in the current update.
"We assume that this method lived our sensitivity to dark particles by more than an order of magnitude – while we already used skills at the LHC," Liu said.
Experimenters are already working on setting up the trap: When the LHC powers up again in 2021 after increasing its luminosity In ten ways, all three major detectors will implement the new system, the scientists said. "We believe there is great potential for discovery," Liu said.
"When the particle is there, all we have to do is find a way to find out," Wang said. "Usually the key is to find the question."
CERN laboratory on the hunt for dark matter
Jia Liu et al. Improving the Search for Long-lived Particles in the LHC with Accurate Timing Information, Physical Review Letters (2019). DOI: 10.1103 / PhysRevLett.122.131801
Scientists invent a way to capture mysterious particles from the "dark world" at the Large Hadron Collider (2019, April 18)
retrieved on April 18, 2019
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