by Ten years after the Higgs boson was discovered, the Large Hadron Collider is about to start smashing protons to unprecedented energy levels in its quest to reveal more secrets about how the universe works.
The world’s largest and most powerful particle collider was back online in April after a three-year hiatus for upgrades in preparation for its third run.
Starting Tuesday, it will run 24 hours a day for nearly four years with a record power of 13.6 trillion electron volts, the European Organization for Nuclear Research (CERN) announced at a news 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-kilometre (17-mile) ring buried 100 meters below the Franco-Swiss border.
Thousands of scientists will record and analyze the resulting collisions as part of a series of experiments, including ATLAS, CMS, ALICE and LHCb, that will use the enhanced power to investigate dark matter, dark energy and other fundamental mysteries.
– 1.6 billion collisions per second –
“Our goal is to deliver 1.6 billion proton-proton collisions per second” for the ATLAS and CMS experiments, said Mike Lamont, CERN’s chief technology officer and accelerators.
This time, the proton beams will be reduced to less than 10 microns (a human hair is about 70 microns thick) to increase the collision rate, he added.
The new rate of energy will allow them to further investigate the Higgs boson, which the Large Hadron Collider first observed on July 4, 2012.
The discovery revolutionized physics in part because the boson fit within the Standard Model, the leading theory of all the fundamental particles that make up matter and the forces that govern them.
However, several recent findings have raised questions about the Standard Model, and the recently updated collider will look at the Higgs boson in more depth.
“The Higgs boson is related to some of the deepest open 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 that discovered the boson, this time there will be 20 times more collisions.
“This is a significant increase, paving the way for new discoveries,” Lamont said.
Joachim Mnich, director of research and computation at CERN, said there was still much to learn about the boson.
“Is the Higgs boson really a fundamental particle or is it a compound?” she asked.
“Is it the only Higgs-like particle in existence, or are there others?”
– ‘New season of physics’ –
Previous experiments have determined the mass of the Higgs boson, as well as more than 60 composite 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 how, our goal is to understand why,” he said.
Among the nine Large Hadron Collider experiments are ALICE, which investigates matter that existed in the first 10 microseconds after the Big Bang, and LHCf, which uses 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.
Beyond that, scientists are planning a Circular Collider of the Future, a 100-kilometer ring that aims to reach energies of a whopping 100 trillion electron volts.
But for now, physicists are eagerly awaiting the results of the Large Hadron Collider’s third run.
“A new season of physics begins,” CERN said.
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