The world’s most powerful particle collider, the Large Hadron Collider (LHC), will start smashing protons against each other at unprecedented energy levels from July 5.
Scientists will record and analyze the data, which should provide evidence for “new physics” – or physics beyond the Standard Model of particle physics, which explains how the basic building blocks of matter interact, govern by four fundamental forces.
The Large Hadron Collider is a giant, complex machine designed to study particles which are the smallest known building blocks of all things.
Structurally, it is a 27 km long loop of track buried 100 meters underground at the Franco-Swiss border. In its operational state, it shoots two beams of protons near the speed of light in opposite directions inside a ring of superconducting electromagnets.
The magnetic field created by the superconducting electromagnets keeps the protons in a narrow beam and guides them as they travel through the beam tubes and eventually collide.
“Just before the collision, another type of magnet is used to ‘squeeze’ the particles together to increase the risk of collision. The particles are so tiny that the task of colliding them is like throwing two needles 10 km apart with such precision that they meet halfway,” according to the European Organization for Nuclear Research (at originally Conseil Européen pour la Recherche Nucléaire, or CERN, in French), which manages the particle accelerator complex that houses the LHC.
Since the LHC’s powerful electromagnets carry almost as much current as lightning, they must be kept cold. The LHC uses a liquid helium delivery system to keep its critical components ultracold at minus 271.3 degrees Celsius, which is colder than interstellar space. Given these requirements, it is not easy to heat or cool the gigantic machine.
Three years after it was shut down for maintenance and upgrades, the collider was reignited in April. This is the LHC’s third run and, from Tuesday, it will run around the clock for four years at unprecedented energy levels of 13 teraelectronvolts. (A TeV is 100 billion, or 10 to the power of 12 electron volts. An electron volt is the energy given to an electron by accelerating it through 1 volt of electrical potential difference.)
“We are aiming to produce 1.6 billion proton-proton collisions per second” for the ATLAS and CMS experiments, CERN’s Head of Accelerators and Technology Mike Lamont said, according to an AFP report. This time, the proton beams will be shrunk to less than 10 microns – a human hair is about 70 microns thick – to increase the collision rate, he said.
(ATLAS is the largest general-purpose particle detection experiment at the LHC; the Compact Muon Solenoid (CMS) experiment is one of the largest international scientific collaborations in history, with the same goals as ATLAS, but which uses a different magnet system design. )
Previous races and discovery of “God Particle”
Ten years ago, on July 4, 2012, scientists at CERN announced to the world the discovery of the Higgs boson or “god particle” during the first run of the LHC. The discovery concluded the decades-long search for the ‘force-carrying’ subatomic particle and proved the existence of the Higgs mechanism, a theory put forward in the mid-sixties.
This led to Peter Higgs and his collaborator François Englert being awarded the Nobel Prize in Physics in 2013. The Higgs boson and its associated energy field are said to have played a vital role in the creation of the universe.
The second LHC run (Run 2) started in 2015 and lasted until 2018. The second season of data collection produced five times more data than Run 1.
The third run will see 20 times more collisions than run 1.
After the discovery of the Higgs boson, scientists began to use the collected data as a tool to look beyond the Standard Model, which is currently the best theory of the most basic building blocks of the universe and their interactions. .
CERN scientists say they don’t know what run 3 will reveal; the hope is to use the collisions to further the understanding of so-called ‘dark matter’.
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This hard-to-detect and hoped-for particle is thought to make up most of the universe, but it is completely invisible because it does not absorb, reflect or emit light.
Luca Malgeri, a CERN scientist, told Reuters: “CERN scientists hope it can be spotted, even fleetingly, in the debris of billions of collisions, just as the Higgs boson has been.”