Side view of the Large Hadron Collider CMS detector. Photo: CERN
- On July 4, 2012, physicists working with the Large Hadron Collider experiment in Europe announced that they had found the Higgs boson, 48 years after it was predicted.
- The Higgs boson is an excitation in the Higgs field, an energy field that permeates the universe and gives its mass to subatomic elementary particles.
- His discovery was a great success, but there are still many things we do not know about the Higgs boson, including an important mystery related to its own mass.
- Physicists around the world are also considering whether they need a larger particle collider to unravel this and other mysteries, in which the Higgs boson may also have a hand.
Ten years ago on this day, scientists in the world’s largest physics experiment announced that they had discovered the Higgs boson. The discovery of this subatomic particle validated the idea that the Higgs field, an energy field that permeates the universe and gives its mass to subatomic particles, is real.
Proving that the Higgs boson exists is also proof that the Higgs mechanism exists, first predicted in the 1960s. Thus, the discovery of the particle closed an important avenue of physical research after many decades of celebration and fanfare.
However, he added new questions to the pile of unsolved mysteries.
From what questions they would like to have answered and how, today’s physicists have to make crucial decisions about what their next experiments will do and at what price. The colossal device that helped physicists find the Higgs boson was the Large Hadron Collider (LHC), a 27 km long tube in which protons accelerate with the help of very powerful magnets at almost the speed of light, and has broken frontally. Collider detectors, including two called ATLAS and CMS, study the detritus of these collisions to detect signs of the Higgs boson.
The Higgs field gives mass to subatomic particles using the Higgs mechanism. The existence of the mechanism was predicted by three independent groups in 1964. One of these groups was only Peter Higgs, a British theoretical physicist. The other groups were 1) Robert Brout and François Englert and 2) Gerald Guralnik, CR Hagen and Tom Kibble.
Most people refer to the mechanism as the Higgs mechanism, but Peter Higgs has said he calls it the “Anderson-Brout-Englert-Guralnik-Hagen-Higgs-Kibble-‘t Hooft mechanism.” ‘Anderson’ means Philip Warren Anderson and ‘t Hooft’ for Gerardus’ t Hooft.
Following the discovery of the particle, Peter Higgs and François Englert received the Nobel Prize in Physics in 2013.
ATLAS Collaboration Spokeswoman Fabiola Gianotti presents evidence of the discovery of the Higgs boson at CERN, July 4, 2012. Photo: CERN
A photon is a particle that physicists understand to be an excitation of the electromagnetic energy field. Similarly, the Higgs boson is an excitation in the Higgs field. The force with which the Higgs boson interacts with a particle is proportional to the mass of the particle. Thus, for example, the upper quark is the heaviest elementary particle known to interact more strongly with the Higgs boson. The less strong the interaction with the Higgs boson, the lighter a particle will be.
(Note that only elementary particles obtain their mass through the Higgs mechanism. Compound particles, such as protons and neutrons, can obtain their mass from many sources, only one of which is that of their constituent particles.)
That said, based on 10-year data from the LHC, physicists have so far studied the interactions of the Higgs boson with heavier particles rather than lighter ones, such as electrons and positrons. Physicists also need to study more how the Higgs boson attaches to itself, to explain how the particle gets its own mass.
The Higgs boson is often called the “particle of God,” but the particle has no theological connotations, unlike several pseudoscientific articles that have appeared in the popular press since its discovery. This name is a modification of “damn particle”, which is what physicist Leon Lederman called the Higgs boson in 1993 because it was very difficult to find.
In fact, the LHC is a proportionately impressive machine: the largest scientific experiment still today, 12 years after it began operating. But finding the Higgs boson has been the latest of the LHC’s sensational discoveries. To be fair, the LHC has supported numerous incremental findings and helped improve the accuracy of some findings and invalidate or modify others. The machine has also given negative results that have restricted several theoretical predictions.
For example, we do not know what dark matter is. Some theories predict dark matter particles with some properties. LHC physicists then look for evidence of these particles in their detectors, at different energies. (The energy at which a particle is located is important because it is related to the mass of the particle and indicates to which other particles it can disintegrate.)
So far, the LHC has found no evidence of these particles. This has meant not that dark matter particles do not exist, but that these particles, if they exist, do not exist in the energies and other conditions in which the LHC sought them.
Another equally important problem is the mass of the Higgs boson: it is much heavier than Higgs et al. predicted it would be. Because? There is another related issue. The existing framework of rules that physicists use to understand the properties of subatomic particles is called the standard model. And he predicts that the mass of the Higgs boson is unstable and could change drastically someday, with catastrophic consequences for the universe (and a mystery also related to the mass of an unusual particle called the upper quark). Could it really be?
These two questions have important implications for our understanding of the universe, and it also means that the standard model could be wrong or incomplete in some way. But we don’t know how.
Read also: We discovered the Top Quark 25 years ago. Its mass is still fascinating. (2020)
A popular solution to these problems is called supersymmetry. It is a theory that predicts that each particle of matter has a particle of complementary force, and vice versa. These complementary particles are called supersymmetric partners. If we found them, the mathematics of the existing particle rules would change in a way that could explain why the mass of the Higgs boson is what it is.
Many physicists expected the LHC to find supersymmetric partners, but so far the data has been left blank. One such negative result prompted a UK spokesman for one of the collaborations at the LHC to tell the BBC in 2012: “Supersymmetry may not have died, but these latest results have certainly taken to hospital. “
This was not a positive result, but that doesn’t mean it wasn’t informative.
The LHC and its detectors receive periodic updates that improve their sensitivity, resolution, timing, collision output, and more. After the last round of updates, starting in December 2018, the LHC reopened on April 22nd. The next round of updates will take place in 2026..
The period during which the LHC collects data between updates is called “execution.” Each run produces a large amount of data that physicists (using computers) cannot finish processing in that run. Many of them are still examining the data produced in previous executions, looking for interesting results.
View of the LHC operations center, May 21, 2021, when the machine reached a proton collision energy of 13 TeV for the first time. Photo: CERN
As for the Higgs boson itself, there are many unanswered questions. They can be divided into three types, significant summer:
* What we already know but we need to know better – For example, we have only studied the interactions of the Higgs boson with particles called leptons and quarks with an accuracy of up to 5%. This is not good enough: we need the data to be much more accurate because there is a possibility that with higher accuracy, the observed numbers will deviate from what was predicted by the theory. This in turn could mean, according to one hypothesis, for example, that the Higgs boson is not a fundamental particle but is made up of smaller particles.
* What we don’t know yet but hope to know – Is there only one “type” of Higgs boson? How do two Higgs bosons interact with each other? How does the Higgs boson interact with lighter particles? Does the disintegration of a Higgs boson follow or violate existing laws of physics? Are there ways of decay that we have not yet found? Why is the mass of the Higgs boson much lower than what physicists’ calculations say it should be?
* What can the Higgs boson tell us about other mysteries – Why does our universe have more matter than antimatter? What is dark matter? Why did cosmic inflation happen?
Finding the answers to any of these questions in themselves does not mean that they enjoy immunity to doubt. The new information we discover could raise old questions in a new light and, as with the discovery of the Higgs boson, generate more, and probably more important, questions.
The next logical step in this direction is to improve the LHC – which is already planned – and, later, find ways to study the interactions of the Higgs boson with particles that cannot occur in sufficient quantities in collisions. the LHC.
That is why, although both the LHC and the LHC data will exist for at least two more decades, producing a wealth of data that will help physicists improve existing measurements, physicists, and others, have also begun to think what kind of machine. They should then build a machine that can elucidate the Higgs boson dance with the other particles. Start thinking now why plan and build …