Scientists announced ten years ago Discovery of the Higgs boson, which helps explain why elementary particles (the smallest building blocks in nature) have mass. For particle physicists, this is the end of a long and very difficult journey of decades – and arguably the most important result in the history of the field. But the end also marked the start of a new era of experimental physics.
In the last decade, measurements of the properties of the Higgs boson have confirmed the predictions of Standard Model of Particle Physics (Our best particle theory). But it also raises questions about the limitations of this model, such as whether there is a more fundamental theory of nature.
physique Peter Higgs The Higgs boson was predicted in a series of papers between 1964 and 1966, as an inevitable consequence of the mechanism responsible for giving the particle its ground mass. This theory states that the mass of a particle is the result of the interaction of elementary particles with a field called the Higgs field.
According to the same model, this field must also give rise to the Higgs particle – meaning that if the Higgs boson did not exist, it would eventually falsify the whole theory.
But it soon became clear that detecting these particles would be difficult. When three theoretical physicists calculate the properties of the Higgs boson, End with an apology: “We apologize to experimental experts for not knowing about the mass of the Higgs boson… and for being unsure about its incorporation with other particles… for this reason, we don’t want to encourage a massive experimental search for the Higgs boss.”
Finding the Higgs boson
The first experiment took the great opportunity to find the Higgs boson until 1989 to start research. The idea is to destroy the particles with such high energy that Higgs particles can be created in a 27 km long tunnel at CERN in Geneva, Switzerland – the largest electron-positron (positron is almost identical to the electron but has the opposite charge) collision ever made. It lasted 11 years, but it turned out that the maximum energy was only 5% lower to produce the Higgs boson.
Meanwhile, the most ambitious American fist in history, and Tevatron, retrieved data at Fermilab, near Chicago. The tevatron collides with protons (which make up the nucleus of an atom along with neutrons) and antiprotons (nearly identical to protons but with the opposite charge) at energies five times higher than those achieved at Geneva—enough, of course, to make the Higgs. But proton and antiproton collisions produce a lot of debris, which makes extracting signals from the data more difficult. In 2011, Tevatron operations stopped – the Higgs boson had escaped detection again.
In 2010, Large Hadron Collider It began to collide with protons with seven times the energy of the Tevatron. Finally, on July 4, 2012, two independent experiments at CERN gathered enough data to announce the discovery of the Higgs boson. The following year, Higgs and his collaborator François Englert won the Nobel Prize “For theoretical discoveries of mechanisms that contribute to our understanding of the origin of the mass of subatomic particles.”
It’s almost selling it short. Without the Higgs boson, the entire theoretical framework that explains particle physics at its smallest scale would be destroyed. The elementary particles would have no mass, and there would be no atoms, no humans, no solar system, no structure in the universe.
Trouble on the horizon
However, this discovery has raised new fundamental questions. Experiments continue at CERN investigating the Higgs boson. Its properties determine not only the mass of elementary particles, but also their stability. As it stands, the results show that our universe is out of reach Really stable condition.
Or, similar to ice at its melting point, the universe could suddenly undergo rapid “phase transitions.” But instead of going from solid to liquid, like ice to water, this would involve an important change in mass — and the laws of nature in the universe.
The fact that the universe remains visibly stable suggests that something might be missing in the calculations – something we haven’t discovered yet.
After three years of maintenance and upgrade breaks, collisions at the Large Hadron Collider will continue with unprecedented energy, nearly double the energy used to find the Higgs boson. This could help find the missing particles that move our universe away from the knife edge between stability and velocity transitions.
Experience can help answer other questions as well. Could it be that the unique properties of the Higgs boson made it a gateway to discovering dark matter, the invisible matter that makes up most of the matter in the universe? Dark matter is not charged. And the Higgs boson He has a unique way of interacting With uncharged materials.
The same unique properties make physicists wonder if the Higgs boson might not be a fundamental particle. Could there be a new, unknown force that surpasses the other forces of nature – gravity, electromagnetism, the weak and strong nuclear forces? Could it be the force that binds hitherto unknown particles to the compound body we call the Higgs boson?
Such a theory can help resolve disputes Latest measurement results Which indicates that some particles do not behave as the Standard Model suggests. So studying the Higgs boson is essential to see if there is any physics to be found outside of the Standard Model.
determinant
Ultimately, the Large Hadron Collider will have the same problem as the Tevatron. The proton collisions are chaotic and the energy of the collisions will only go so far. While we have a full arsenal of modern particle physics – including state-of-the-art detectors, advanced detection methods, and machine learning – at our disposal, there are limits to what the Large Hadron Collider can achieve.
Future high-energy collisions, specifically designed to produce the Higgs boson, will allow us to accurately measure its most important properties, including how the Higgs boson interacts with other Higgs bosons. This, in turn, will determine how the Higgs boson interacts with its own field. So studying these interactions can help us investigate the fundamental processes that give particles mass. Any disagreements between theoretical predictions and future measurements This will be a very clear sign We need to discover a completely new physics.
These measurements will have a profound impact far beyond Collider physics, directing or limiting our understanding of the origin of dark matter, the birth of our universe — and perhaps its eventual fate.
Martin Power Professor of Physics at Durham University. Stephen Jones Assistant Professor of Physics at Durham University.
This article first appeared on Conversation.
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