PARIS: The Large Hadron Collider restarted on Friday after a three-year hiatus for upgrades that will allow it to bind protons together at even higher speeds, in the hope of making groundbreaking new discoveries.
It will further study the Higgs boson, shown to exist in 2012, and put the standard model of particle physics to the test after recent anomalies spawned theories about a mysterious fifth force in nature.
“Two beams of protons circled in opposite directions around the 27-kilometre ring of the Large Hadron Collider” shortly after noon on Friday, the European physics laboratory CERN said in a statement.
Buried more than 100 meters (330 feet) below the border of Switzerland and France, the collider has been closed since December 2018 for maintenance and upgrades, the second-longest closure in its 14-year history.
For starters, the collider is taking it easy. A “relatively small number of protons” circulated at an energy of 450 billion electron volts, CERN said.
“High-intensity, high-energy collisions are a couple of months away,” said CERN beam department head Rhodri Jones.
CERN said its experts will “work day and night” to prepare the collider to set a new record of 13.6 trillion electron volts.
The unprecedented number of upcoming collisions will also serve as the kick-off for four years of massive data collection and analysis by CERN’s four huge particle detectors.
‘An exciting few years’
The Large Hadron Collider’s observation of the Higgs boson was seen as further verification of the Standard Model, which is the best theory scientists have for the most basic building blocks of the universe and what forces govern them.
But the new phase of collider exploration comes at an interesting time, with the Standard Model under pressure for a series of measurements that don’t seem to fit within its framework.
Earlier this month, more than 400 scientists said that after a decade of measurements they had found that the W boson has a significantly higher mass than the standard model allowed.
Harry Cliff, a particle physicist at the University of Cambridge, said the collider upgrade means “it’s going to be an exciting few years”.
Cliff studies particles called beauty quarks in the beauty of the Large Hadron Collider (LHCb) and said they “are not behaving as we expected” under the Standard Model. “All of these anomalies could be explained by a single new force,” Cliff said. AFP.
There are currently four known fundamental forces of nature: gravity, electromagnetism, and the strong and weak nuclear forces, and a fifth would be “a really big deal,” he said.
Another explanation could be that we know less than we thought.
It could be that “we’re actually looking at one corner of the picture, and there’s a much larger picture where the standard model makes a lot of sense,” Cliff said. Either way, it would be “a step on the way to a more unified understanding of the basic ingredients of the universe,” he said.
One of the biggest holes in the standard model is that it doesn’t account for dark matter, which is thought to make up a significant part of the universe.
So far, the Large Hadron Collider has found no signs of dark matter.
“By its nature, it’s hard to detect,” Cliff said. But he added that “it would be a breakthrough if we could find a dark matter particle.”
Posted in Alba, April 23, 2022