The July 4, 2012 the researchers in the Large Hadron Collider announced that they had found the last piece of a puzzle that had been incomplete for 48 years.
The Large Hadron Collider is the machine larger and more complex that has never been built; the piece he found is a particle of the subatomic world, and it is one of the elemental blocks that make up everything we know.
That piece is Higgs boson, and the verification of its existence is one of the greatest achievements of modern physics.
With the discovery of the Higgs boson, the Standard Modelwhich describes the set of elementary particles that make up everything we know, and the forces that interact with each other to make them work like pieces of Lego that are assembled.
The feat of the Large Hadron Collider was the culmination of an adventure that began in 1964, when the British physicist Peter Higgs published a theory that predicted that the boson must exist.
According to Higgs himself, that was “the only good idea” he had in his life, and at first he believed that his theory was nothing more than useless calculations.
What actually happened, however, is that the particle that you theorized and that the collider later found to exist, revolutionized the understanding of our universe.
That one good idea earned the Higgs the Nobel Prize in Physics in 2013, and paradoxically, ruined his lifeas he himself tells it.
In 2022 the tenth anniversary that the Large Hadron Collider detected the Higgs boson.
At BBC Mundo we talked with two specialists regarding how this tiny particle celebrates a decade helping us answer two big questions of humanity: Where do we come from and what are we made of?
The Standard Model
For a long time it was thought that atoms were the particles most elementary what everything is made of.
Then we learned that those atoms are actually made of even smaller particles: atoms. protons and neutrons that make up the nucleus of the atom, and the electrons that orbit that nucleus.
But today, we know that even those protons and neutrons can be broken down into particles. even smaller.
In total, 17 fundamental particles have been detected, which, when interacting with each other due to the influence of forces, make up the entire universe that we know.
That set of 17 particles and forces is known as the Standard Model.
These particles are divided into two large families: fermions and bosons.
The Fermions: which are the bricks from which the entire universe is made. They are like Lego pieces that, depending on how they are combined, form different atoms. There are 12 fermions, divided into six quarks and six leptons. In other words: all the matter we know is made up of combinations of quarks and leptons. Or more generally: everything we see is made of fermions.
The bosons: they are the particles that carry the forces that make the fermions interact. In total there are five types of bosons, each of them carrying one of the three fundamental forces that make matter interact:
1. The gluon that carries the strong force that holds quarks together;
2 and 3. The W boson and the Z boson, which carry the weak force, which causes the nucleus of an atom to disintegrate and form another atom;
4. Photons, which carry the electromagnetic force.
There is also a fourth force, perhaps the most famous of all: the gravity.
It just so happens that gravity at the subatomic level is so weak that its influence can be largely ignored, so it’s not part of the Standard Model.
In this way we have almost complete the standard model: the family of fermions interacts with the family of bosons to form the universe.
What is the Higgs boson?
We have already seen 12 fermions and 4 bosons, that is, 16 of the 17 pieces of the Standard Model.
We are only missing the piece that completes the model: the Higgs boson.
The Higgs boson is needed to answer a key question: particles like quarks and leptons have mass with which to form matter. But where do those particles get their mass?
The answer is the so-called Higgs field, an invisible environment that permeates the entire universe and impregnates the particles that navigate in it with mass.
In that Higgs field are the Higgs bosons, which are the ones that smear the particles that make up matter with mass.
“The discovery of the Higgs boson showed us that there is a strange thing in which we are all immersed, and that is known as the Higgs field,” Frank Close, Emeritus Professor of Theoretical Physics at the University of Oxford, tells BBC Mundo. .
“Just as fish need to be immersed in water, we need the Higgs field,” says Close, author of the book “Elusive: How Peter Higgs Solved the Mystery of Mass” (in its literal translation into Spanish).
In 1964 Peter Higgs was one of the first to theorize the existence of that field and the first to predict that there must be a particle associated with that field.
But it was only in 2012, thanks to the Large Hadron Collider, that it was possible to observe that this particle, which we now know as the Higgs boson, actually exists beyond theory.
Why was this finding so important?
For Saúl Noé Ramos Sánchez, a researcher at the Institute of Physics of the National Autonomous University of Mexico, there are three major milestones that marked the discovery of the Higgs boson and that marked our understanding of the universe.
1. It gave us a complete knowledge of the elementary particles that make us up
“All the particles that make up our atoms have finally been understood, including their relationships with other particles,” Ramos Sánchez tells BBC Mundo.
2. A particle was found unlike all the others
The Higgs boson does not look like electrons, nor does it look like protons, and it is responsible for certain interactions that lead to knowledge of the mass of these particles.
That is, the Higgs boson is the key piece that tells us why the other particles are the way they are.
3. The most precise theory that exists was achieved
Ramos Sánchez maintains that the Standard Model “is the most exact theory that humanity has”.
It is the most precisely known theory.
Close has a similar opinion: “with a few small exceptions, it explains everything we see very well,” says the professor.
The future
Experts agree that following that historic July 4, 2012, there has been another great discovery related to particle physics.
Some recent experiments at the Large Hadron Collider and at Fermilab, another particle accelerator in the United States, have hinted at what might be a new particle or force hitherto unknown.
If that is so, it might raise questions regarding the Standard Model.
However, the results of these experiments are not conclusive.
“After the discovery of the Higgs boson, the Standard Model is more solid than anything else,” says Ramos Sánchez.
But it is also true that there are several questions that the Standard Model fails to answer.
For example, it does not explain what dark matter is, a mysterious component that 27% of the universe is made of.
Nor does it explain why there is more matter than antimatter in the universe, or why the expansion of the cosmos is accelerating.
And another big gap: it fails to include the force of gravity.
Regarding several of these enigmas, several theories have been elaborated, but Neither offers a convincing answer.
But that doesn’t mean the Standard Model is wrong, experts say.
“I wish I was in crisis!” says Close.
“If it were in crisis, that would give us clues that we have to build a great theory that explains what all this is,” adds the professor.
“The ‘problem’ with the Standard Model is that It works very well”.
“We know that it is not the definitive theory, but it is a Complete description of everything to which we have access up to now”.
math trick
According to Close, who for years interviewed him to write his biography, Higgs maintains that the boson “It’s the only good idea he’s ever had.”
In fact, at first, Higgs thought his discovery was something “completely useless”according to Close.
“He thought he had pulled off a simple mathematical trick with which he might theoretically give photons mass. And besides, Higgs was not particularly prolific.
In his entire career he wrote only 12 studies, of those 12, only three, which were related to the Higgs boson, had any relevance, the others were irrelevantaccording to Close.
“And following that he didn’t continue working on it either, He did practically nothing else in that regard.says the professor, it was other people who took his ideas and continued to build knowledge on them and stimulated all the enthusiasm that led to the construction of the Large Hadron Collider.
“Higgs changed the idea of how the universe worksand it’s the only thing he ever did in his life,” says Close.
“So it may have been true that the Higgs boson was the only good idea, but I wonder how many really good ideas any of us have?”
beyond the paper
In 1964 Higgs was not the only one working on the idea of the existence of what we now know as the Higgs field.
Simultaneously, other scientists presented studies that pointed in this direction.
Higgs, however, was the only one to realize that his mathematical idea was true, that is, that it really is. present in nature and it wasn’t just a trick to solve theoretical problems.
“His mathematical trick assumes that there is something strange, which is what we call the Higgs field,” says Close.
“So if that field is real, we should be able to detectand the way to detect it should be what we now call the Higgs boson.”
“Higgs was the only person who noticed that, so the boson was properly baptized in his name.”
“He ruined my life”
After the Large Hadron Collider confirmed the existence of the Higgs boson in 2012, it was almost obvious to the scientific community that the Physics Nobel in 2013 it would be for Higgs.
Higgs himself knew he was the favourite, so on October 8, 2013, when the big announcement was due to be made, his decision was… to vanish.
He left his house, took a bus to a nearby town and took refuge in a bar to enjoy a beer.
In one of his interviews, Close asked Higgs what had been the impact having won the Nobel.
The answer unsettled Close.
“It ruined my life”Higgs told him.
“My existence relatively peaceful it’s over, I don’t enjoy this type of publicity, my style is to work in isolation and occasionally have a brilliant idea”, continued the physicist.
That way of being explains why he fled the day of the Nobel announcement.
According to Close, however, going into hiding had the opposite effect which Higgs expected.
“What is more attractive for a journalist?” Close asks. “A man who wins the Nobel and is there ready for you to interview him, or someone who wins the Nobel and fades away?”.
In 2022 Peter Higgs is 93 years old and living in retirement in Edinburgh, Scotland.
He doesn’t use the internet, only the phone, and he lives in a building without an elevator where he has to go down 84 steps to reach the street.
For Close, all of this shows elusive which is Peter Higgs, as elusive as the famous boson that spent years hiding and by letting itself be seen changed our perception of the universe forever.