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Higgs boson


Prof. Peter Higgs has revealed he did not know he had won the Nobel Prize until a woman congratulated him in the street.

Prof. Peter Higgs, 84, who does not own a mobile phone, said a former neighbor had pulled up in her car as he was returning from lunch in Edinburgh.

He added: “She congratulated me on the news and I said <<oh, what news?>>”

The woman had been alerted by her daughter in London that Prof. Peter Higgs had won the award, he revealed.

He added: “I heard more about it obviously when I got home and started reading the messages.”

The emeritus professor at the University of Edinburgh was recognized by the Royal Swedish Academy of Sciences for his work on the theory of the particle which shares his name, the Higgs boson.

Prof. Peter Higgs shares this year’s physics prize with Francois Englert of Belgium, and joins the ranks of past Nobel winners including Marie Curie and Albert Einstein.

Prof. Peter Higgs has revealed he did not know he had won the Nobel Prize until a woman congratulated him in the street

Prof. Peter Higgs has revealed he did not know he had won the Nobel Prize until a woman congratulated him in the street

The existence of the so-called “God particle”, said to give matter its substance, or mass, was proved almost 50 years later by a team from the European nuclear research facility (CERN) and its Large Hadron Collider (LHC) in Geneva, Switzerland.

Speaking for the first time about the award at a media conference at the University of Edinburgh, he said: “How do I feel? Well, obviously I’m delighted and rather relieved in a sense that it’s all over. It has been a long time coming.”

An old friend told him he had been nominated as far back as 1980, he said.

Prof. Peter Higgs added: “In terms of later events, it seemed to me for many years that the experimental verification might not come in my lifetime.

“But since the start up of the LHC it has been pretty clear that they would get there, and despite some mishaps they did get there.”

Stressing the involvement of other theorists and CERN, he added: “I think clearly they should, but it is going to be even more difficult for the Nobel Committee to allocate the credit when it comes to an organization like CERN.

“I should remind you that although only two of us have shared this prize, Francois Englert of Brussels and myself, that the work in 1964 involved three groups of people, (including) two in Brussels.

“Unfortunately Robert Brout died a few years ago so is no longer able to be awarded the prize, but he would certainly have been one of the winners if he had still been alive.

“But there were three others who also contributed and it is already difficult to allocate the credit amongst the theorists.

“Although a lot of people seem to think I did all this single-handed, it was actually part of a theoretical programme which had been started in 1960.”

Prof. Peter Higgs was born in Newcastle, but developed his theory while working at the University of Edinburgh.

The landmark research that defined what was to become known as the Higgs boson was published in 1964.

Discovering the particle became one of the most sought-after goals in science, and the team of scientists behind the $10 billion LHC at CERN made proving its existence a key priority.

In July of last year, physicists at CERN confirmed the discovery of a particle consistent with the Higgs boson.

Prof. Peter Higgs, who had often been uncomfortable with the attention his theory brought, was in Geneva to hear the news, and wiped a tear from his eye as the announcement was made.

Reacting to the discovery at the time, Prof. Peter Higgs told reporters: “It’s very nice to be right sometimes.”

The Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs for their work on the theory of the Higgs boson.

Peter Higgs, from the UK, and François Englert from Belgium, shared the prize “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”.

In the 1960s they were among several physicists who proposed a mechanism to explain why the most basic building blocks of the Universe have mass.

The mechanism predicts a particle – the Higgs boson – which was finally discovered in 2012 at the Large Hadron Collider at CERN, in Switzerland.

The Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs for their work on the theory of the Higgs boson

The Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs for their work on the theory of the Higgs boson

“This year’s prize is about something small that makes all the difference,” said Staffan Normark, permanent secretary of the Royal Swedish Academy of Sciences.

FrançoisEnglert said he was “very happy” to win the award.

“At first I thought I didn’t have it [the prize] because I didn’t see the announcement,” he told the Nobel committee, after their news conference was delayed by more than an hour.

Prof. Peter Higgs, of the University of Edinburgh, said: “I am overwhelmed to receive this award and thank the Royal Swedish Academy.

“I would also like to congratulate all those who have contributed to the discovery of this new particle and to thank my family, friends and colleagues for their support.

“I hope this recognition of fundamental science will help raise awareness of the value of blue-sky research.”

CERN director general Rolf Heuer said he was “thrilled” that this year’s prize had gone to particle physics.

“The discovery of the Higgs boson at CERN last year, which validates the Brout-Englert-Higgs mechanism, marks the culmination of decades of intellectual effort by many people around the world,” he said.

Large Hadron Collider (LHC) scientists have announced that the particle outlined in July 2012 looks increasingly to be a Higgs boson.

Higgs boson, long theorized as the means by which particles get their mass, had been the subject of a decades-long hunt at the world’s particle accelerators.

Yet there is still some uncertainty as to whether the particle is indeed a Higgs boson, and if so, what type it is.

Results at the Moriond meeting in Italy suggest strongly that the particle’s “spin” is consistent with a Higgs.

Teams from the two Higgs-hunting experiments, Atlas and CMS, analyzed two-and-a-half times more data than were available in July in an effort to pin down not only the particle’s existence, but also something about its character.

All that is conclusively established is that the particle is in the family of bosons, but researchers had been careful since July to describe it as “Higgs-like”.

The zoo of subatomic particles are characterized by properties including their “spin” and “parity” – and the precise establishment of these properties for the new particle will determine if it is beyond doubt the long-sought Higgs.

What is more, theories predict that a number of different types of Higgs may exist.

The simplest form – that which fits neatly into the existing Standard Model of particle physics – would surely shore up the theory, but the possible existence of more “exotic” versions of the particle would open exciting new vistas in science.

LHC scientists have announced that the particle outlined in July 2012 looks increasingly to be a Higgs boson

LHC scientists have announced that the particle outlined in July 2012 looks increasingly to be a Higgs boson

“This is the start of a new story of physics,” said Tony Weidberg, Oxford University physicist and a collaborator on the Atlas experiment.

“Physics has changed since July the 4th – the vague question we had before was to see if there was anything there,” he said.

“Now we’ve got more precise questions: is this particle a Higgs boson, and if so, is it one compatible with the Standard Model?”

The results reported at the conference – based on the entire data sets from 2011 and 2012 – much more strongly suggest that the new particle’s “spin” is zero – consistent with any of the theoretical varieties of Higgs boson.

“The preliminary results with the full 2012 data set are magnificent and to me it is clear that we are dealing with a Higgs boson, though we still have a long way to go to know what kind of Higgs boson it is,” said CMS spokesperson Joe Incandela.

As is often the case in particle physics, a fuller analysis of data will be required to establish beyond doubt that the particle is a Higgs of any kind.

However, Dr. Tony Weidberg said that even these early hints were compelling.

“This is very exciting because if the spin-zero determination is confirmed, it would be the first elementary particle to have zero spin,” he said.

“So this is really different to anything we have seen before.”

Even more data will be required to explore the question of more “exotic” Higgs particles.

A popular but as-yet unsubstantiated theory called supersymmetry suggests there should be as many as five Higgs particles – a notion that will have to remain speculative at least until new data are acquired after the LHC’s two-year shutdown for refurbishment.

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Scientists say they may be able to determine the eventual fate of the cosmos as they probe the properties of the Higgs boson.

A concept known as vacuum instability could result, billions of years from now, in a new universe opening up in the present one and replacing it.

It all depends on some precise numbers related to the Higgs that researchers are currently trying to pin down.

A “Higgs-like” particle was first seen at the Large Hadron Collider (LHC) last year.

Associated with an energy field that pervades all space, the boson helps explain the existence of mass in the cosmos. In other words, it underpins the workings of all the matter we see around us.

Since detecting the particle in their accelerator experiments, researchers at the Geneva lab and at related institutions around the world have begun to theorize on the Higgs’ implications for physics.

One idea that it throws up is the possibility of a cyclical universe, in which every so often all of space is renewed.

“It turns out there’s a calculation you can do in our Standard Model of particle physics, once you know the mass of the Higgs boson,” explained Dr. Joseph Lykken.

“If you use all the physics we know now, and you do this straightforward calculation – it’s bad news.

“What happens is you get just a quantum fluctuation that makes a tiny bubble of the vacuum the Universe really wants to be in. And because it’s a lower-energy state, this bubble will then expand, basically at the speed of light, and sweep everything before it,” said the Fermi National Accelerator Laboratory theoretician.

It was not something we need worry about, he said. The Sun and the Earth will be long gone by this time.

Scientists say they may be able to determine the eventual fate of the cosmos as they probe the properties of the Higgs boson

Scientists say they may be able to determine the eventual fate of the cosmos as they probe the properties of the Higgs boson

Dr. Joseph Lykken was speaking here in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS).

He was participating in a session that had been organized to provide an update on the Higgs investigation.

The boson was spotted in the wreckage resulting from proton particle collisions in the LHC’s giant accelerator ring.

Data gathered by two independent detectors observing this subatomic debris determined the mass of the Higgs to be about 126 gigaelectronvolts (GeV).

That was fascinating, said Prof. Chris Hill of Ohio State University, because the number was right in the region where the instability problem became relevant.

“Before we knew, the Higgs could have been any mass over a very wide range. And what’s amazing to me is that out of all those possible masses from 114 to several hundred GeV, it’s landed at 126-ish where it’s right on the critical line, and now we have to measure it more precisely to find the fate of the Universe,” he said.

Prof. Chris Hill himself is part of the CMS (Compact Muon Solenoid) Collaboration at the LHC. This is one of the Higgs-hunting detectors, the other being Atlas.

Scientists have still to review about a third of the collision data in their possession. But they will likely need much more information to close the uncertainties that remain in the measurement of the Higgs’ mass and its other properties.

Indeed, until they do so, they are reluctant to definitively crown the boson, preferring often to say just that they have found a “Higgs-like” particle.

Frustratingly, the LHC has now been shut down to allow for a major programme of repairs and upgrades.

“To be absolutely definitive, I think it’s going to take a few years after the LHC starts running again, which is in 2015,” conceded Dr. Howard Gordon, from the Brookhaven National Laboratory and an Atlas Collaboration member.

“The LHC will be down for two years to do certain repairs, fix the splices between the magnets, and to do maintenance and stuff. So, when we start running in 2015, we will be at a higher energy, which will mean we’ll get more data on the Higgs and other particles to open up a larger window of opportunity for discovery. But to dot all the I’s and cross all the T’s, it will take a few more years.”

If the calculation on vacuum instability stands up, it will revive an old idea that the Big Bang Universe we observe today is just the latest version in a permanent cycle of events.

“I think that idea is getting more and more traction,” said Dr. Joseph Lykken.

“It’s much easier to explain a lot of things if what we see is a cycle. If I were to bet my own money on it, I’d bet the cyclic idea is right,” he said.

Particle accelerator Large Hadron Collider (LHC) has turned off its particle beams ahead of a shut-down period that will last two years.

The LHC is best known for its role in spotting the Higgs boson in late 2012.

But following technical faults shortly after it first switched on, the machine has never been run at the full energies for which it was designed.

A programme of repairs and upgrades should allow that in late 2014.

The LHC’s beams were “dumped” early on Thursday morning, but it will take until Saturday morning for the machine’s 1,734 magnets to warm up to room temperature.

Then an unprecedented period of upgrade and repair – dubbed “Long Shutdown 1” – will begin.

The machine ran at particle energies of 8 trillion electron-volts (TeV) in 2012, up from the prior high point of 7TeV in 2011. But when the shutdown concludes, slated for the end of November 2014, it should be set to run at 13TeV – far and away the highest-energy collisions ever attempted by scientists.

The LHC is best known for its role in spotting the Higgs boson in late 2012

The LHC is best known for its role in spotting the Higgs boson in late 2012

The major work required is to upgrade the connections between the magnets, such that they can handle the enormous electrical currents that may pass through them at higher particle energies and in the event of faults such as the one in 2008.

But the shutdown maintenance schedule also includes upgrades to all four of the LHC’s detectors, the shielding of electronics – even the ventilation system of the 27 km-long tunnel that houses the main accelerator ring.

The shutdown is due to conclude in late November 2014, after which the system will be put through its paces and experiments are expected to resume in February or March 2015.

CERN scientists reporting at conferences in the UK and Geneva, Switzerland, claim the discovery of a new particle consistent with the Higgs boson.

The particle has been the subject of a 45-year hunt to explain how matter attains its mass.

Both of the two Higgs-hunting experiments at the Large Hadron Collider have reached a level of certainty worthy of a “discovery”.

More work will be needed to be certain that what they see is a Higgs, however.

Both teams claimed they had seen a “bump” in their data corresponding to a particle weighing in at about 125-126 gigaelectronvolts (GeV) – about 130 times heavier than the proton at the heart of every atom.

The results announced at CERN, home of the LHC in Geneva, were each met with thunderous applause.

CERN scientists reporting at conferences in the UK and Geneva claim the discovery of a new particle consistent with the Higgs boson

CERN scientists reporting at conferences in the UK and Geneva claim the discovery of a new particle consistent with the Higgs boson

Prof. Peter Higgs, the former University of Edinburgh theoretician who with five others predicted the Higgs particle’s existence in 1964, praised the LHC teams, calling the results “a testament to the expertise of the researchers”.

“I never expected this to happen in my lifetime and shall be asking my family to put some champagne in the fridge,” he said.

The CMS team claimed that by combining two of its data sets, they had attained a confidence level just at the “five-sigma” point – about a one-in-3.5 million chance that the signal they see would appear if there were no Higgs particle.

However, a full combination of the CMS data brings that number just back to 4.9 sigma – a one-in-2 million chance.

Joe Incandela, spokesman for CMS, was unequivocal.

“The results are preliminary but the five-sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle,” he told the Geneva meeting.

Fabiola Gianotti, spokeswoman for the ATLAS experiment, announced even more irrefutable results.

“We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV,” she said.

Anticipation had been high and rumors were rife before the announcement.

Indications are strong, but it remains to be seen whether the particle the team reports is in fact the Higgs – those answers will certainly not come on Wednesday.

A confirmation would be one of the biggest scientific discoveries of the century; the hunt for the Higgs has been compared by some physicists to the Apollo programme that reached the Moon in the 1960s.

Two different experiment teams at the LHC observe a signal in the same part of the “search region” for the Higgs – at a rough mass of 125 GeV.

Hints of the particle, revealed to the world by teams at the LHC in December 2011, have since strengthened markedly.

The $10 billion LHC is the most powerful particle accelerator ever built: it smashes two beams of protons together at close to the speed of light with the aim of revealing new phenomena in the wreckage of the collisions.

The ATLAS and CMS experiments, which were designed to hunt for the Higgs at the LHC, each detect a signal with a statistical certainty of more than 4.5 sigma.

Five sigma is the generally accepted benchmark for claiming the discovery of a new particle. It equates to a one in 3.5 million chance that there is no Higgs and the “bump” in the data is down to some statistical fluctuation.

Prof. Stefan Soldner-Rembold, from the University of Manchester, said earlier this week: “The evidence is piling up… everything points in the direction that the Higgs is there.”

The Higgs is the cornerstone of the Standard Model – the most successful theory to explain the workings of the Universe.

But most researchers now regard the Standard Model as a stepping stone to some other, more complete theory, which can explain phenomena such as dark matter and dark energy.

Once the new particle is confirmed, scientists will have to figure out whether the particle they see is the version of the Higgs predicted by the Standard Model or something more exotic.

Scientists will look at how the Higgs decays or – transforms – into other, more stable particles after being produced in collisions at the LHC.

The Standard Model is the simplest set of ingredients – elementary particles – needed to make up the world we see in the heavens and in the laboratory

Quarks combine together to make, for example, the proton and neutron – which make up the nuclei of atoms today – though more exotic combinations were around in the Universe’s early days

Leptons come in charged and uncharged versions; electrons – the most familiar charged lepton – together with quarks make up all the matter we can see; the uncharged leptons are neutrinos, which rarely interact with matter

The “force carriers” are particles whose movements are observed as familiar forces such as those behind electricity and light (electromagnetism) and radioactive decay (the weak nuclear force)

The Higgs boson came about because although the Standard Model holds together neatly, nothing requires the particles to have mass; for a fuller theory, the Higgs – or something else – must fill in that gap

 

Scientists at the Large Hadron Collider (LHC) are expected to reveal the strongest evidence yet for the Higgs particle in Geneva, Switzerland, shortly.

Anticipation is high and rumors have been rife about the announcement.

The Higgs boson would help explain why particles have mass, and fills a glaring hole in the current best theory to describe how the Universe works.

The strength of the LHC’s signal is understood to be just short of the benchmark for claiming a “discovery”.

But it will show that researchers are now tantalisingly close to confirming the Higgs’ existence and bringing to an end the decades-long quest for the most coveted prize in physics.

The $10 billion LHC is the most powerful particle accelerator ever built: it smashes two beams of protons together at close to the speed of light with the aim of revealing new phenomena in the wreckage of the collisions.

But why has so much time and effort been invested in detecting the boson?

Mass is a measure of how much stuff an object – such as a particle or molecule – contains. If it were not for mass, all of the fundamental particles that make up atoms would whiz around at light-speed and the Universe as we know it would never have clumped into matter.

The Higgs boson would help explain why particles have mass, and fills a glaring hole in the current best theory to describe how the Universe works

The Higgs boson would help explain why particles have mass, and fills a glaring hole in the current best theory to describe how the Universe works

According to the theory, all of space is filled by a field – known as the Higgs field, which is mediated by particles known as Higgs bosons.

Other particles gain mass when they interact with the field, much as a person feels resistance from the water – drag – as they wade through a swimming pool.

The boson is the last missing particle in the Standard Model, the most widely accepted theory of how the cosmos works. But the Higgs remains a theoretical construct that has never been observed in a particle accelerator.

Four of the six theoretical physicists credited with coming up with the Higgs mechanism in the 1960s – including Prof Peter Higgs, after whom it is named – have been invited to CERN in Geneva for the presentations, fuelling anticipation of a major announcement.

Unconfirmed reports suggest that the signal detected at a mass of 125 gigaelectronvolts (GeV), which was announced in December, has since strengthened.

“We now have more than double the data we had last year,” said CERN’s director for research and computing, Sergio Bertolucci.

“That should be enough to see whether the trends we were seeing in the 2011 data are still there, or whether they’ve gone away. It’s a very exciting time.”

Discovering particles is a numbers game, and scientists analyze many events that could be representative of a Higgs boson being produced in the LHC.

The hints of the Higgs revealed in 2011 had a statistical certainty of just two sigma.

Three sigma represents about one in 700 likelihood that a “bump” in the data is down to some statistical fluctuation, in the absence of a Higgs. But the benchmark for a discovery is five sigma, denoting a one-in-3.5 million likelihood that a result is down to such a fluctuation.

Rumors suggest the certainty level has now crept beyond four sigma. This might not be enough to announce that scientists have found the elusive particle. But it would suggest the LHC’s scientists are within touching distance, and several physicists privately say that such a signal is now unlikely to go away.

Also, the idea that some systemic error could affect all the experiments that see hints of the Higgs – including those at the LHC and the US Tevatron machine (which search for the particle in different ways) – seems just as improbable.

But if and when a new particle is discovered, it will not be clear straight away that it is the Higgs. Physicists will need to characterize its properties in order to confirm whether it is the version of the Higgs predicted by the Standard Model, a “non-conformist” Higgs that hints at new laws of physics, or something else entirely.

This will involve years of detailed and difficult work, said Dr. Tony Weidberg, a University of Oxford physicist and member of one of the LHC’s experimental teams, Atlas.

He said that even at a certainty level of five sigma, “you’re very far from proving it’s a Higgs particle at all, let alone a Standard Model Higgs”.

 

Scientists at CERN in Switzerland will announce that the elusive Higgs boson “God Particle” has been found at a press conference next week, according to new reports.

Five leading theoretical physicists have been invited to the event on Wednesday – sparking speculation that the particle has been discovered.

Scientists at the Large Hadron Collider are expected to say they are 99.99% certain it has been found – which is known as “four sigma” level.

Physicists first predicted that the Higgs Boson subatomic particle exists 48 years ago.

Peter Higgs, the Edinburgh University emeritus professor of physics that the particle is named after, is among those who have been called to the press conference in Switzerland.

Scientists at CERN in Switzerland will announce that the elusive Higgs boson “God Particle” has been found at a press conference next week

Scientists at CERN in Switzerland will announce that the elusive Higgs boson “God Particle” has been found at a press conference next week

The management at CERN wants the two teams of scientists to reach the “five sigma” level of certainty with their results – so they are 99.99995% sure – such is the significance of the results.

The Higgs boson is regarded as the key to understanding the universe. Physicists say its job is to give the particles that make up atoms their mass.

Without this mass, these particles would zip though the cosmos at the speed of light, unable to bind together to form the atoms that make up everything in the universe, from planets to people.

The collider, housed in an 18-mile tunnel buried deep underground near the French-Swiss border, smashes beams of protons – sub-atomic particles – together at close to the speed of light, recreating the conditions that existed a fraction of a second after the Big Bang.

If the physicists’ theory is correct, a few Higgs bosons should be created in every trillion collisions, before rapidly decaying.

This decay would leave behind a “footprint” that would show up as a bump in their graphs.

However, despite 1,600 trillion collisions being created in the tunnel – there have been fewer than 300 potential Higgs particles.

Now it is thought that two separate teams of scientists, who run independent experiments in secret from each other, have both uncovered evidence of the particle.

However, the two groups, CMS and ATLAS, are expected to stop short of confirming its existence.

 

Large Hadron Collider’s detector Atlas captured a particle that physicists had suspected to exist for years, but had never seen “in the wild”.

The Chi b (3P) particle was detected among data from the trillions of collisions at the LHC.

The CERN discovery was hailed as testimony to how effectively physicists were now scanning the collision data – and essential background to the LHC’s ongoing quest for the Higgs, a theoretical particle which is thought to “explain” why the universe has mass.

Physicists scan the data from the LHC’s detectors for “unusual” signals from the debris of high-energy collisions. This new particle is an important milestone for the collider – and a crucial step in its mission to fill in the gaps in our understanding of physics.

Professor Stefan Soldner-Rembold, a particle physicist at the University of Manchester said the Higgs “will always be the Nobel Prize”, but that this discovery is still very exciting.

What’s been discovered, Prof. Stefan Soldner-Rembold explained, is a particle comprised of a bottom quark and a bottom anti-quark – an entirely new kid on the sub-atomic block that until now was merely a theory.

He said: “It’s exciting confirmation of the theory of strong interactions that keeps these particles together, the same theory that describes how a nucleus sticks together.

“What they’ve found is a b-quark and an anti b-quark.

“Quarks cannot be seen by themselves, they’re contained in a particle and held together with the strong force. If you understand how the force works, you can predict which particles should exist.

“With all these different quarks you can play Lego and put them together in different ways and form new particles, similar to protons, that can be combined to form elements.”

Large Hadron Collider’s detector Atlas captured a particle that physicists had suspected to exist for years, but had never seen “in the wild”

Large Hadron Collider’s detector Atlas captured a particle that physicists had suspected to exist for years, but had never seen “in the wild”

The results were put online on the scientific publication site ArXiv.

The find is an important step for the LHC – which is more than a machine built solely to hunt for the Higgs boson.

Finding particles such as Chi b (3P) is crucial to filling in the gaps in the Standard Model – the way we understand physics.

The LHC was designed to fill in these gaps – and help physicists “move on” to the Higgs and “new physics”.

A senior CERN physicist from Switzerland has announced this afternoon firm evidence for the existence of the elusive Higgs Boson, or God particle.

Although the signal doesn’t meet strict scientific standards for a “full scientific discovery”, it’s still enough for researchers at CERN’S Large Hadron Collider (LHC) to predict a discovery next year.

Two separate teams of scientists have been running independent experiments in secret from each other in order to improve the veracity of the results with the team leader of one, Fabiola Gianotti, proclaiming that they believe they’ve found signs of the Higgs boson in the past year.

“We have built a solid foundation for the months ahead,” Fabiola Gianotti said.

However, CERN was cautious: “The main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass constrained to the range 116-130 GeV [a unit of energy equal to billion electron volts] by the ATLAS experiment, and 115-127 GeV by CMS.

“Tantalizing hints have been seen by both experiments in this mass region, but these are not yet strong enough to claim a discovery.

“Higgs bosons, if they exist, are very short lived and can decay in many different ways. Discovery relies on observing the particles they decay into rather than the Higgs itself. Both ATLAS and CMS have analyzed several decay channels, and the experiments see small excesses in the low mass region that has not yet been excluded.”

The upshot of the experiments, therefore, is that researchers believe the Higgs is fairly lightweight, which could lead to more exciting discoveries, according to New Scientist’s Lisa Grossman.

Lisa Grossman wrote: “A Higgs of this mass, about 125 gigaelectronvolts, would blast a path to uncharted terrain. Such a lightweight would need at least one new type of particle to stabilize it.”

A senior CERN physicist from Switzerland has announced this afternoon firm evidence for the existence of the elusive Higgs Boson, or God particle

A senior CERN physicist from Switzerland has announced this afternoon firm evidence for the existence of the elusive Higgs Boson, or God particle

When looking at results, the scale of certainty used by researchers is the sigma, something peculiar to particle physics.

Researchers need a five-sigma level of certainty to make a bona-fide formal discovery, which means there’s only a one in a million chance that the result is a statistical error.

Scientists only formally acknowledge an experiment’s results if they hit a three sigma level, which means there’s only a 1 in 370 chance of them being a fluke.

The sigma probabilities announced today for the Higgs hunt have not been combined, but the overall ATLAS result was 2.3.

Before the press conference began, CERN described the room as “full to the rafters. People would hang from the lamps if the security guards would let them”.

The Higgs boson is regarded – by those who know about such things – as the key to understanding the universe. Its job is, apparently, to give the particles that make up atoms their mass.

Without this mass, these particles would zip though the cosmos at the speed of light, unable to bind together to form the atoms that make up everything in the universe, from planets to people.

The Higgs boson’s existence was predicted in 1964 by Edinburgh University physicist Peter Higgs. But it has eluded previous searchers – so much so that not all scientists believe in its existence.

The hunt for the Higgs boson was one of the LHC’s major tasks.

The collider, housed in an 18-mile tunnel buried deep underground near the French-Swiss border, smashes beams of protons – sub-atomic particles – together at close to the speed of light, recreating the conditions that existed a fraction of a second after the Big Bang.

If the physicists’ theory is correct, a few Higgs bosons should be created in every trillion collisions, before rapidly decaying.

This decay would leave behind a “footprint” that would show up as a bump in their graphs.

The CMS – or Compact Muon Solenoid – is a 13,000-ton machine that sits 330 feet underground, while the ATLAS, at 148 feet long and 82 feet high, is the biggest detector ever constructed.

From the Big Bang to the 1960s

The existence of the Higgs boson was put forward in the 1960s to explain why the tiny particles that make up atoms have mass.

Theory has it that as the universe cooled after the Big Bang, an invisible force known as the Higgs field formed.

This field permeates the cosmos and is made up of countless numbers of tiny particles – or Higgs bosons.

As other particles pass through it, they pick up mass.

Any benefits in the wider world from the discovery of the Higgs boson will be long term, but they could be felt in fields as diverse as medicine, computing and manufacturing.

Experts compare the search for the Higgs boson to the discovery of the electron.

The idea of the electron – a subatomic particle – was first floated in 1838, but its presence was not confirmed for another 60 years.

A century on, the electron’s existence underpins modern science. Our understanding of it is critical to the development of technology from television and CDs to radiotherapy for cancer patients