Event recorded with the CMS detector in 2012 at a proton-proton centre-of-mass energy of 8 TeV. The event shows characteristics expected from the decay of the SM Higgs boson to a pair of photons (dashed yellow lines and green towers). The event could also be due to known standard model background processes.
The long awaited results of the ATLAS and CMS experiments were announced today at CERN, The European Organization for Nuclear Research, revealing that a new particle in the mass region of 125-126 GeV has been found. The elementary particle, the Higgs boson, gives all particles their masses through what is called Higgs mechanism.
“We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.”
This publication of the analyses shown today is expected around the end of July. But the results, labelled ‘preliminary’, are based on data collected in 2011 and 2012, with the 2012 data still under analysis.
"The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle. We know it must be a boson and it’s the heaviest boson ever found,” said CMS experiment spokesperson Joe Incandela.
The 5 sigma significance of the result represents the highest confident level, and means it's very unlikely this result is a mistake.
Nobel Laureate Carlo Rubbia, who won the Physics Nobel in 1984 for contributions which led to the discovery of the field particles W and Z, communicators of weak interaction, stressed this, stating; “I would like to underline this is a preliminary measurement, it’s a sign of success and result, but I mean, making the LHC is not a scoop, it’s a 20 year program” he said.
Though among the other Nobel Laureate’s attending this year’s Lindau Nobel Laureate Meetings, Rubbia was excited by the discovery, stating it was an “experimental result of a fantastic nature, it doesn’t happen every day,” he said. “It is normal when you build a machine of this magnitude that you get some surprises,” stated Rubbia.
According to Rubbia, work for this $10 billion Large Hadron Collider particle accelerator, 100 meters underground near Geneva, isn’t over yet. With the discovery comes a greater opportunity for further research, with the current goal now to determine the precise nature of the particle and its significance for our understanding of the universe.
“We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”
The big question now is: are the properties, as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. However, a more exotic version of the Higgs particle could very well be a bridge to clearing the shroud of mystery that surrounds the universe and solving the 96% of the universe that remains obscure.
Australian Nobel Prize winner, Brian Schmidt, was also excited by the announcement, “The model by which we understand the quantum world has been verified with a confidence, 99.9999% confidence” stated Schmidt, who although excited about the discovery, lost a bet. “I bet against the Higgs with my former office mate, Sean Carroll, I should have never bet against it…now I have to fly him and his wife, business class to Australia” he stated.
Though not all the Laureate’s reaction has been positive, Nobel Laureate Martinus Veltman, who won the Nobel Prize in 1999 for elucidating the quantum structure of electroweak interaction sin physics, admitted that the discovery was a bit of an anti-climax. “We will not make any other projects until we find something else…finding a standard model with close the door,” said Veltman.
However Nobel Laureate David Gross, who won the physics Nobel in 2004 for the discovery of asymptotic freedom in the theory of strong interaction, was more optimistic, stating “Every bit of information that becomes more verified gives us information, that’s what physics lives on, so we have today a little more information than we had yesterday."
The physicist was also excited for the 36th International Conference on High Energy Physics to be held in Melbourne this month; “After next week in Melbourne we’ll have even more [information] and believe me, theorist and experimentalist will be looking at that information for clues about what observations to do, what anomaly to concentrate on, what theories to throw out and what models to continue developing,” said Gross.
Having a definitive mass for the particle marks the end of a chapter and the entering a new one in particle physics, according to Gross. “This is the end, in the sense that we have been expecting a discovery of this nature for 30 years, nature was slightly unkind and postponed it.”
Though according to Rubbia, nature has a will of its own. “We are on the verge of turning a page, I will not know myself what that page will be, and I would prefer to let nature decide” he stated.
The Nobel Laureates will be engaged in discussions with over 590 young researchers from around the globe this afternoon to deliberate the matter at the Lindau Nobel Laureate Meetings.
Editor's Note: Katrina Beavan is attending the Nobel Laureate Meetings in Lindau for ScienceAlert and will be keeping us up to date with all the latest news from the conference. Katrina is an avid travel blogger and politics enthusiast with a passion for languages, travel and science. In her last year of a Journalism and arts degree, she works as a freelance journalist and has written travel stories, reviews and more for various online sites. Reporting for ABC radio during the Australian floods was a highlight in her career.