Ten years after the discovery of the Higgs boson, the Large Hadron Collider is on the verge of smashing together protons at unprecedented energy levels to reveal more mysteries about how the universe works.
The world’s largest and most powerful particle accelerator restarted in April after a three-year hiatus for upgrades in preparation for its third run.
From Tuesday, it will run around the clock for almost four years with a record energy of 13.6 trillion electron volts, the European Organization for Nuclear Research (CERN) announced at a press conference last week.
It will send two beams of protons – particles in the nucleus of an atom – in opposite directions at nearly the speed of light around a 27-kilometer ring buried 100 meters below the Swiss-French border.
The resulting collisions will be recorded and analyzed by thousands of scientists as part of a series of experiments including ATLAS, CMS, ALICE and LHCb, which will use the improved performance to study dark matter, dark energy and other fundamental mysteries.
– 1.6 billion collisions per second –
“We aim to deliver 1.6 billion proton-proton collisions per second for the ATLAS and CMS experiments,” said CERN’s director of accelerators and technology, Mike Lamont.
This time, the proton beams will be narrowed to less than 10 microns – a human hair is about 70 microns thick – to increase the collision rate, he added.
The new energy rate will allow them to further study the Higgs boson, which the Large Hadron Collider first observed on July 4, 2012.
The discovery revolutionized physics in part because the boson fit into the Standard Model — the mainstream theory of all the fundamental particles that make up matter and the forces that control them.
However, some recent findings have raised questions about the Standard Model, and the newly upgraded collider will take a closer look at the Higgs boson.
“The Higgs boson is connected to some of the most profound unanswered questions in fundamental physics today,” said CERN Director General Fabiola Gianotti, who first announced the boson’s discovery a decade ago.
Compared to the first run of the collider, where the boson was detected, this time there will be 20 times more collisions.
“This is a significant increase that paves the way for new discoveries,” said Lamont.
Joachim Mnich, head of CERN’s research and computing department, said there was much more to learn about the boson.
“Is the Higgs boson really an elementary particle or a composite?” he asked.
“Is it the only existing Higgs-like particle – or are there others?”
– ‘New Physics Season’ –
Previous experiments have determined the mass of the Higgs boson, as well as more than 60 compound particles predicted by the Standard Model, such as the tetraquark.
But Gian Giudice, head of CERN’s theoretical physics department, said observing particles is only part of the job.
“Particle physics doesn’t just want to understand the how – our goal is to understand the why,” he said.
The Large Hadron Collider’s nine experiments include ALICE, which studies matter that existed in the first 10 microseconds after the Big Bang, and LHCf, which uses the collisions to simulate cosmic rays.
After this run, the Collider will return in 2029 as the High-Luminosity LHC, increasing the number of detectable events by a factor of 10.
In addition, the scientists are planning a Future Circular Collider – a 100-kilometer-long ring that should reach energies of a whopping 100 trillion electron volts.
But now physicists are eagerly awaiting the results of the third run of the Large Hadron Collider.
“A new physics season begins,” said CERN.
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