£720m Large Hadron Collider upgrade ‘could shake up particle physics’ | Large Hadron Collider

A massive project to supercharge the world’s largest particle collider was launched on Friday in hopes the boosted machine will reveal new information about the nature of the universe.

The 950m Swiss franc (£720m) mission will see the installation, construction and excavation of heavy equipment, new buildings, access shafts and service tunnels at the Large Hadron Collider (LHC) of Cern, the particle physics laboratory on the outskirts of Geneva.

The vast machine, which occupies a 27 km circular tunnel under the Franco-Swiss border, chases away signs of new physics by smacking subatomic particles at near-light speed. Conforms to Einstein’s law E=mc2part of the impact energy is converted into new material.

The upgrade will make the collider far more susceptible to subtle quirks in the laws of physics, and physicists hope these anomalies will open the door to entirely new theories of the universe.

In 2012, LHC physicists announced the discovery of the Higgs boson, which had leapt into fleeting existence inside the machine’s detectors when bunches of hydrogen nuclei, or protons, crashed into each other. billions of times. This discovery won a Nobel Prize for Peter Higgs and Belgian physicist François Englert for their theoretical work on the particle in the 1960s.

If the upgrade goes as planned, the proton beams in the bloated accelerator, known as the High-Luminosity LHC, or HL-LHC, will be so intense that the number of collisions in the machine will be five to ten. times greater than today.

“The High-Luminosity LHC is where we will collect most of our data, and in that sense it is the phase of our exploration that allows us to know the most about the universe,” Tara said. Shears, professor of physics at the University of Liverpool. working on the collider’s LHCb detector. “If until now the LHC has given us a candle to illuminate what was previously invisible, the High-Luminosity LHC will allow us to light a spotlight.

Physicists are already exploring some strange signals at the LHC that could be the first clues that the so-called Standard Model of particle physics is on the verge of collapse. The Standard Model is a series of equations that describe how particles such as electrons and quarks found inside atoms interact with each other. The theory works wonders, but physicists know it’s incomplete: it says nothing about gravity, or the dark matter that clings to galaxies, or the dark energy that causes space to expand. universe, or why the world around us is made of matter. instead of antimatter.

The curious signals seen at the LHC in recent months are too faint to convince most physicists that they are real, but if they grow stronger over time, as happened with the Higgs boson, they could reveal the existence of completely unexpected new particles, called leptoquarks or Z primes.

To increase the number of collisions at the LHC, engineers will install powerful magnets to compress protons into thinner, denser beams. Next, they plan to install devices called crab cavities that use an electromagnetic pulse to kick proton bunches sideways as they enter the LHC detectors. This spins the protons a bit before they hit protons coming the other way, increasing the number of collisions. They are called crab cavities because they cause the proton bunches to move laterally, even if the rotation is very small.

“It’s a very exciting time,” said Rob Appleby, a particle physicist at the University of Manchester and UK spokesperson for the HL-LHC. “It opens the door to the most precise and sensitive era of fundamental physics we have ever seen.”

The upgrade is expected to take eight years. While new magnets and beam instruments will be installed when the LHC is shut down for two years in 2019, most of the required equipment will be installed during a longer shutdown from 2024 to 2026, when the revamped machine is restarted.

“If the anomalies we are seeing in the LHC now show up in the next couple of years, which they might well do, what we will be looking at with the High-Luminosity LHC is the physics underlying these findings” , said Val Gibson. , professor of physics at Cambridge University who also works on the collider’s LHCb detector. “It would overturn the standard model. It would be totally revolutionary.

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