Editor TLN
Ten years ago, physicists captured the attention of the entire world in a way that has not been repeated since. On July 4, 2012, a gigantic team made up of 5,000 researchers from the world’s largest particle accelerator, the Large Hadron Collider (LHC) of the European laboratory CERN, announced the discovery of Higgs’ Boson. This particle is considered responsible for giving mass to all the others and without it the universe would not exist as we know it.
The finding completed the standard model, the great theory that for decades has served to describe reality and the laws that govern it, and confirmed a prediction made 45 years earlier by the British physicist peter higgs and the Belgians François Englert Y Robert Brout. The first could not help crying with emotion when he saw his calculations come true. A year later he won the Physics Nobel with his colleague Englert. A round win.
Higgs’ Boson
What was to come seemed even more exciting. After the Higgs, a door to an unknown world was expected to open. It was possible that other new particles could collide in the 27-kilometre ring-shaped LHC that could shed light on the mysteries of the cosmos. Among them, the dark matter, invisible even to our most advanced instruments but believed to be five times more abundant than the ordinary one, the one we do see; the dark energy, even more mysterious and responsible for the accelerated expansion of the universe; or the quantum nature of gravity.
But in this decade the search has not been fruitful and the journey in the desert is too long. The expected ones have not been located supersymmetric particlesone of the possible explanations for dark matter, neither mini black holes nor much less a good clue to unify the forces of nature.
Today, July 5, and after three years of hiatus due to updating and maintenance work, and the delay due to the pandemic, the gigantic machine located under the Franco-Swiss border will begin its third round of activity (Run 3) without leaving of its entrails no wonder apart from the Higgs. For some physicists, the results are clearly disappointing. And the pressure increases.
The Higgs was shot
«The Higgs was achieved by shot after preliminary experiments at CERN and Fermilab (high energy laboratory in the USA). The English expression for this kind of feat is ‘hunting ducks in a barrel’. This is not to be detracted from, but it is clear that the enormous funding for the construction of the LHC —required about 5,000 million euros— would never have been obtained for this unique result»explains Juan Collar, a physics professor at the University of Chicago who works on detecting dark matter in smaller experiments. “The great promise was supersymmetry. It has not appeared and it is understandable to feel disappointed »Add.
According to this proposal, each of the known particles must have an associated ‘superparticle’, very similar but with subtly different characteristics, among them a much greater mass. It could contain the keys for the unification of the two forces of nature that still resist us, the strong nuclear force and gravity. And even provide a candidate particle to be the smallest unit of dark matter.
credibility in question
Barry Barish, 2017 Nobel Prize in Physics for observation of gravitational waves, also shown “upset” due to the lack of confirmation of this “attractive idea”but believes it more likely that different phenomena will appear that, with luck, open the way to «a new physics, which we know must be there, beyond the standard model».
But that could take a long time and end the patience of the scientific community, which does not consider the funding justified and is betting on less grandiose alternatives to the LHC. Very critical and open “pessimistic”Collar believes that finding new particles might require energies and fluxes unattainable by any known accelerator technology.
“It’s like when they give you a lottery tenth share… probabilities exist, but I don’t think anyone is holding their breath”, ironically In his opinion, if nothing else is found in this field in the coming years “The credibility of accelerator physicists will take a huge hit. I would be very surprised if this financing could be obtained again, from any government»he points out.
LHC
And it is that maintaining the LHC is not exactly cheap. Its budget this year was 1,200 million euros, of which Spain contributes 86 million. Celso Martínez, from the Physics Institute of Cantabria (IFCA, joint University of Cantabria-CSIC center) and representative in Spain of the CMS, one of the LHC detectors that found the Higgs, assumes that it is a very high amount and that many people can question, but believes it is justified.
“We work with public money and we are aware that it is difficult to convince everyone why these expenses are necessary. -recognize-. But this is basic research. What we are doing is like Christopher Columbus advancing through the ocean: to see what we find, without knowing where or when we are going to arrive».
With the same firmness, he defends the work being done at the accelerator by Carlos Lacasta, an IFIC researcher and representative of the ATLAS experiment. He remembers the days of finding a Higgs compatible particle as “exciting” and the “culmination of many years of work”. In his opinion, having ‘hunted’ the boson and having the instrument with which to accurately measure its properties “meets all expectations”. Also, “There is still a lot of analysis work to be done with the data that has been taken so far and no surprises can be ruled out”.
energy record
The new particles, if they exist, have a new opportunity to show their faces in Run 3. The LHC will gradually increase the energy of the collisions, until reaching the maximum power at the end of July: a record of 13.6 billion electron volts (13.6 TeV) —the energy at which the Higgs appeared was 7.8 TeV— and will double the number of collisions per second —some 120 particles will collide with each other—, which will increase the number of data collected over the next three years.
And if it goes on without a ‘eureka’, “It is also a discovery in itself. It tells us that nature has not chosen the path we thought was the right one.”Lacasta says. Would it spell the end of particle physics? “Absolutely not!”says Barish. “The progress of physics can sometimes be spectacular and other times more gradual. I think we’re likely to see the latter.”he reflects.
For Lacasta, «The study of the properties of the Higgs will take time and it could happen that it is not exactly as predicted». He predicts that nature will return “to put us in our place by teaching us that he has his own designs”. Let’s not forget «that at the end of the 19th century it was believed that physics had already explained all the phenomena». Isaac Newton couldn’t even imagine the quantum world, so who knows what’s to come.
Font: Judith de Jorge / ABC
Reference article: https://www.abc.es/ciencia/abci-temor-no-encontrar-nada-mas-diez-anos-sobre-higgs-202207030133_noticia.html
