The Large Hadron Collider was reignited today (July 5) and is expected to smash particles together at energy levels never seen before.
The Large Hadron Collider (LHC) is the largest and most powerful particle accelerator in the world. Located at CERN near Geneva, Switzerland, the nearly 17-mile (27 kilometer) loop was launched today after spending four years offline for upgrades. Once these fixes are complete, scientists want to use the gigantic accelerator to smash protons to record energies of up to 13.6 trillion electron-volts (TeV) – an energy level that should increase the chances that the the accelerator produces particles not yet observed by science.
Improvements to the accelerator’s particle beams have done more than boost their energy range; an increased level of compactness, making the beams more particle dense, will increase the probability of a collision so much that the accelerator should capture more particle interactions in its third run than it did in its previous two combined. During the two previous periods, from 2009 to 2013 and from 2015 to 2018, the atom smasher has enhanced physicists’ understanding of how the basic building blocks of matter interact – called the standard model — and led to the discovery of the long prediction the Higgs bosonthe elusive particle that gives all matter its mass.
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But, despite the accelerator experiments, which have produced 3,000 scientific papers on many minor discoveries and tantalizing hints of deeper physics, scientists have yet to find conclusive evidence of new particles or a whole new physics. After this update, they hope that will change.
“We will measure the forces of the Higgs boson’s interactions with matter and force particles with unprecedented precision, and we will continue our research into Higgs boson decays to black matter particles as well as the search for additional Higgs bosons”, Andreas Hoecker, LHC Spokesperson ATLAS collaborationan international project that includes physicists, engineers, technicians, students and support staff, said in a statement (opens in a new tab).
Inside the LHC’s 27 km long underground ring, protons travel at close to the speed of light before colliding. The result? New and sometimes exotic particles are formed. The faster these protons go, the more energy they have. And the more energy they have, the more massive the particles they can produce when they collide. Atom breakers like the LHC detect possible new particles by looking for telltale decay products, since heavier particles usually have a short lifespan and immediately decay into lighter particles.
One of the goals of the LHC is to further develop the Standard Model, the mathematical framework used by physicists to describe all known fundamental particles in the universe and the forces by which they interact. Although the model has been around in its final form since the mid-1970s, physicists are far from satisfied with it and are constantly looking for new ways to test it and, if they are lucky, discover new physics that will cause it to fail.
Indeed, the model, despite being the most comprehensive and accurate to date, has huge shortcomings, rendering it completely unable to explain where the strength of gravity where dark matter comes from, or why there is so much more matter than antimatter In the universe.
While physicists want to use the upgraded accelerator to probe the rules of the Standard Model and learn more about the Higgs boson, upgrades to the LHC’s four main detectors also put it in a good position to search for physics beyond. of what is already known. The main LHC detectors – ATLAS and CMS – have been upgraded to collect more than double the data they previously collected in their new task of searching for particles that can persist through two collisions; and the LHCb detector, which now collects 10 times more data than before, will seek breaks in the fundamental symmetries of the universe and explanations why the cosmos contains more matter than antimatter.
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During this time, the ALICE detector will be put to work studying high-energy ion collisions, the recorded number of which will increase by 50 times compared to previous runs. Crashing together, ions – atomic nuclei electrically charged by the removal of electrons from their orbital shells – produce a primordial subatomic soup called quark-gluon plasma, a state of matter that only existed for the first microsecond after the Big Bang.
In addition to these research efforts, many small groups will probe the roots of other mysteries in physics with experiments that investigate the interior of protons; probe the behavior of cosmic rays; and look for the long-theorized magnetic monopole, a hypothetical particle that is an isolated magnet with only one magnetic pole. In addition, there are two new experiments, called FASER (Forward Search Experiment) and SND (Scattering and Neutrino Detector), made possible by the installation of two new detectors during the recent shutdown of the accelerator. FASER will look for extremely light, weakly interacting particles, such as neutrinos and dark matter, and SND will look exclusively for neutrinos, ghostly particles that can pass through most matter without interacting with it.
Particle physicists are particularly excited to search for the axion, a bizarre hypothetical particle that neither emits, absorbs, or reflects light, and is a key suspect for the composition of dark matter.
This third run of the LHC should last four years. After this time, collisions will again be stopped for further upgrades that will push the LHC to even higher power levels. When upgraded and returned to service in 2029, the High-Luminosity LHC is expected to capture 10 times the data from the previous three cycles combined.
Originally posted on Live Science.