The announcement by the Fermi National Accelerator Lab outside Chicago came two days before physicists at CERN, the European particle accelerator near Geneva, are set to unveil their own findings in the Higgs hunt. CERN houses the world's most powerful particle accelerator, the Large Hadron Collider (LHC).
The Fermilab scientists found hints of the Higgs in the debris from trillions of collisions between beams of protons and anti-protons over 10 years at the lab's now-shuttered Tevatron accelerator.
But the evidence still fell short of the scientific threshold for proof of the discovery of the particle, they said, in that the same collision debris hinting at the existence of the Higgs could also come from other subatomic particles.
"This is the best answer that is out there at the moment," said physicist Rob Roser of Fermilab, which is run by the US Department of Energy. "The Tevatron data strongly point toward the existence of the Higgs boson, but it will take results from the experiments at the Large Hadron Collider in Europe to establish a firm discovery."
Scientists have worked long and hard to prove the existence of the Higgs boson, the final piece of a model proposed four decades ago laying out the basic building blocks of matter in the universe.
The Higgs particle's presumed power to confer mass seems to endow it with the power of creation itself, which helped lead to its "God particle" nickname. Many physicists loathe the term, fretting that it makes their discipline seem self-aggrandizing.
Physicists not connected to Fermilab expressed cautious optimism that the long-sought particle had finally been found.
"These intriguing hints from the Tevatron appear to support the results from the LHC shown at CERN in December," said Dan Tovey, professor of particle physics at the University of Sheffield in Britain.
"The results are particularly important because they use a completely different and complementary way of searching for the Higgs boson. This gives us more confidence that what we are seeing is really evidence of new physics rather than just a statistical fluke," Tovey added.
Tovey said scientists will have to wait until Wednesday for the latest results from the European scientists before "getting the full picture" concerning the Higgs boson.
'A nice result'
CERN spokesman James Gillies called Fermilab's findings "a nice result," but added that "it will be interesting to see how it lines up with CERN's results on Wednesday. Nature is the final arbiter so we'll have to be a little more patient before we know for sure whether we've found the Higgs."
Tom LeCompte, a scientist at the Department of Energy's Argonne National Laboratory in Illinois who works at CERN and knows the results, said he was confident the Higgs would be shown to exist, or not exist, this year. But he would not say if the findings to be unveiled Wednesday would be definitive.
"I know 2012 is the year. I can't tell you July is the month," LeCompte said.
Others were less cautious. "This is the most week in physics history," said theoretical physicist Joe Lykken of Fermilab.
The Higgs particle is the final quarry in a hunt that began some 40 years ago, when physicists assembled what is now known as the Standard Model. The model is considered the culmination of a quest for the fundamental constituents of matter and the forces that determine how they interact, a search that began some 2,400 years ago with Greek philosopher Democritus' hypothesis that everything is composed of indivisible atoms.
According to the Standard Model, matter is composed of various combinations of six leptons, including the well-known electron and the ghostly neutrino, and six quarks, to which physicists have given whimsical names such as "charm," "bottom," and "strange." The protons at the core of atoms, for instance, are composed of two "up" quarks and one "down" quark.
The Standard Model also includes particles dubbed bosons, which carry nature's four basic forces.
The best-known boson is the particle of light, the photon. It carries the electromagnetic force, which is responsible for such everyday phenomena as the scent of a rose and the pull of a magnet.
Another boson is called the gluon. It binds together the quarks that constitute protons. Without gluons, quarks would stick together no better than an undercooked souffle, atoms would not exist, and neither would stars, planets or life.
Particle accelerators such as those at CERN and Fermilab methodically discovered all the particles predicted by the Standard Model except one.
Square one
The hold-out is the Higgs boson, and its refusal to show itself has long frustrated physicists. The Higgs particle is needed to complete and validate the Standard Model, since if it turns out not to exist scientists would have to figure out the constituents and mechanics of the universe from square one.
Just as importantly, the existence of Higgs was postulated in 1964 to serve a crucial function: conferring mass on some particles that would otherwise have none. Technically, the Higgs particle itself does not provide mass; the particle is, instead, a little knot of matter squeezed out of a force field like a curd forming in soured milk.
The force field is called - of course - the Higgs field. The Higgs field gives mass to some particles but leaves others alone, in a process one might compare to making cotton candy. As the wand is passed through the gossamer cloud of spun sugar, it holds onto more and more of the pink strands.
In much the same way, particles passing through the Higgs field picked up more and more mass, until they became the quarks and leptons and bosons that constitute the stuff of today's cosmos. In this analogy, some wands are oiled, preventing sugar from sticking; these particles remain without mass. Other wands are super-sticky, picking up more than their fair share of mass.
The particle is named after Peter Higgs, now 83, of the University of Edinburgh in Britain, but five other physicists came up with the same idea almost simultaneously.
"The God Particle" was the title of a 1993 book by Leon Lederman, a Nobel-winning physicist and former head of Fermilab, and science writer Dick Teresi. The publisher vetoed titles with "Higgs" or anything else too esoteric. Lederman later said he wanted to call the book "The Goddamned Particle" because the Higgs was so elusive.
Fermilab began its Higgs quest 10 years ago, using its four-mile (6.4 km) circumference Tevatron to smash together protons and their anti-matter twins, anti-protons. When matter meets anti-matter, the two annihilate, leaving behind pure energy.
Out of that energy crystallize new particles. It was in this debris that the Tevatron scientists sought evidence of the Higgs boson.
Because the Higgs is hypothesized to exist for a mere fraction of a second before decaying into other particles, the strategy was to look for these "daughter" particles.
CERN's 16.7-mile circumference LHC, which smashes protons against protons at nearly the speed of light, looks for two high-energy photons. The Tevatron looked for two bottom quarks. Before budget cuts forced it to shut down last September after trillions of proton-anti-proton collisions, it found as many as 1,000 pairs that could have come from Higgs particles.
"It is a real cliffhanger," said physicist Gregorio Bernardi of the Nuclear Physics Laboratory of High Energies in Paris and leader of one of the Tevatron experiments. "We know exactly what signal we are looking for in our data, and we see some evidence for the production and decay of Higgs bosons in a crucial decay mode with a pair of bottom quarks. So we are very excited."
The Tevatron results indicate that the Higgs particle has a mass between 118 and 132 giga-electron volts (the unit of mass-energy used in physics in which 1 GeV is about the mass of the proton). Last year, the LHC pegged the mass at between 115 and 127 GeV.
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New particle found, consistent with Higgs boson: CERN
Agencies
Geneva, July 04, 2012
Geneva, July 04, 2012
First Published: 13:07 IST(4/7/2012)
Last Updated: 16:46 IST(4/7/2012)
Last Updated: 16:46 IST(4/7/2012)
A document provided on December 13, 2011 by the European Organisation for Nuclear Research (CERN) in Geneva shows a graphic presenting traces of proton-proton collision measured in the Compact Muon Solenoid (CMS) experience. AFP/Cern
Rousing cheers and a standing ovation broke out at the European Organisation for Nuclear Research (CERN) after scientists presented data in their long search for the mysterious particle. The new find is "consistent with (the) long-sought Higgs boson," CERN declared in a statement.
It added further data was needed to identify the find.
"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."
Peter Higgs, a shy, soft-spoken British physicist who published the conceptual groundwork for the particle, back in 1964, expressed joy.
British physicist Peter Higgs at CERN seminar in Geneva. (AFP)
Finding the Higgs would validate the Standard Model, a theory which identifies the building blocks for matter and the particles that convey fundamental forces.
It is a hugely successful theory but has several gaps, the biggest of which is why some particles have mass but others do not.
Mooted by Higgs and several others, the boson is believed to exist in a treacly, invisible, ubiquitous field created by the Big Bang some 13.7 billion years ago.
When some particles encounter the Higgs, they slow down and acquire mass, according to the theory. Others, such as particles of light, encounter no obstacle.
CERN uses a giant underground laboratory where protons are smashed together at nearly the speed of light, yielding sub-atomic debris that is then scrutinised for signs of the fleeting Higgs.
The task is arduous because there are trillions of signals, occurring among particles at different ranges of mass.
Over the years, tens of thousands of physicists and billions of dollars have been thrown into the search for the Higgs, gradually narrowing down the mass range where it might exist.
Two CERN laboratories, working independently of each other to avoid bias, found the new particle in the mass region of around 125-126 Gigaelectronvolts (GeV), according to data they presented on Wednesday.
Both said that the results were "five sigma," meaning there was just a 0.00006 percent chance that what the two laboratories found is a mathematical quirk.
"The results are preliminary but the five sigma signal at around 125 GeV we're seeing is dramatic," said Joe Incandela, spokesman for one of the two experiments.
"This is indeed a new particle. We know it must be a boson and it's the heaviest boson ever found. The implications are very significant and it is precisely for this reason that we must be extremely diligent in all of our studies and cross-checks."
Scientists began to pore over what the historic find could mean.
"(The Higgs) has been anticipated for more than four decades and were it not there theorists all over the world would have been back to their drawing boards in desperation," said Anthony Thomas at the University of Adelaide in Australia.
CERN physicist Yves Sirois agreed.
"This could the Higgs boson that has been found, which may shed light on how matter came into being at the very start of the Universe, a thousandth of a billionth of a second after the Big Bang," he told AFP.
"It may be the Higgs boson, but it may also be something far bigger, which opens the door towards a new theory that goes beyond the Standard Model."
What Is The Higgs Boson? The Higgs is the last missing piece of the Standard Model, the theory that describes the basic building blocks of the universe. The other 11 particles predicted by the model have been found and finding the Higgs would validate the model. Ruling it out or finding something more exotic would force a rethink on how the universe is put together.
Scientists believe that in the first billionth of a second after the Big Bang, the universe was a gigantic soup of particles racing around at the speed of light without any mass to speak of. It was through their interaction with the Higgs field that they gained mass and eventually formed the universe.
The Higgs field is a theoretical and invisible energy field that pervades the whole cosmos. Some particles, like the photons that make up light, are not affected by it and therefore have no mass. Others are not so lucky and find it drags on them as porridge drags on a spoon.
Picture George Clooney (the particle) walking down a street with a gaggle of photographers (the Higgs field) clustered around him. An average guy on the same street (a photon) gets no attention from the paparazzi and gets on with his day. The Higgs particle is the signature of the field - an eyelash of one of the photographers.
The particle is theoretical, first posited in 1964 by six physicists, including Briton Peter Higgs.
The search for it only began in earnest in the 1980s, first in Fermilab's now mothballed Tevatron particle collider near Chicago and later in a similar machine at CERN, but most intensively since 2010 with the start-up of the European centre's Large Hadron Collider.
Former CERN director general Christopher Llewelyn-Smith waves after the presentation of results during a scientific seminar to deliver the latest update in the search for the Higgs boson at the European Organization for Nuclear Research (CERN) in Meyrin near Geneva. (AP Photo)
What Is The Standard Model?
The Standard Model is to physics what the theory of evolution is to biology. It is the best explanation physicists have of how the building blocks of the universe are put together. It describes 12 fundamental particles, governed by four basic forces. But the universe is a big place and the Standard Model only explains a small part of it. Scientists have spotted a gap between what we can see and what must be out there. That gap must be filled by something we don't fully understand, which they have dubbed 'dark matter'. Galaxies are also hurtling away from each other faster than the forces we know about suggest they should. This gap is filled by 'dark energy'. This poorly understood pair are believed to make up a whopping 96% of the mass and energy of the cosmos.
Confirming the Standard Model, or perhaps modifying it, would be a step towards the holy grail of physics - a 'theory of everything' that encompasses dark matter, dark energy and the force of gravity, which the Standard Model also does not explain. It could also shed light on even more esoteric ideas, such as the possibility of parallel universes.
CERN spokesman James Gillies has said that just as Albert Einstein's theories enveloped and built on the work of Isaac Newton, the work being done by the thousands of physicists at CERN has the potential to do the same to Einstein's work.
In this file picture, the magnet core of the world's largest superconducting solenoid magnet (CMS, Compact Muon Solenoid), one of the experiments preparing to take data at CERN's Large Hadron Collider (LHC) particle accelerator is seen, near Genva, Switzerland.(AP Photo)
Two beams of protons are fired in opposite directions around it before smashing into each other to create many millions of particle collisions every second in a recreation of the conditions a fraction of a second after the Big Bang, when the Higgs field is believed to have 'switched on'.
The vast amount of data produced is examined by banks of computers. Of all the trillions of collisions, very few are just right for revealing the Higgs particle. That makes the hunt for the Higgs slow, and progress incremental.
What Is The Threshold For Proof?
To claim a discovery, scientists have set themselves a target for certainty that they call "5 sigma". This means that there is a probability of less than one in a million that their conclusions from the data harvested from the particle accelerator are the result of a statistical fluke.
The two teams hunting for the Higgs at CERN, called Atlas and CMS, now have twice the amount of data that allowed them to claim 'tantalising glimpses' of the Higgs at the end of last year and this could push their results beyond that threshold.
Why Is It Important?
The origin of mass -- meaning the resistance of an object to being moved -- has been fiercely debated for decades.
Finding the Higgs boson would vindicate the so-called Standard Model of physics, a theory that developed in the early 1970s, which says the Universe is made from 12 particles which provide the building blocks for all matter.
These fundamental particles are divided into a bestiary comprising six leptons and six quarks, which have exotic names such as "strange," "up", "tau" and "charm."
Why Is It Called The Higgs Boson?
The name comes from a British physicist, Peter Higgs, today aged 83, who conceived of a field of mass-conferring particles in 1964 and became the first to publish his idea.
Important theoretical work was also done separately by Belgian physicists Robert Brout, who died in 2011, and Francois Englert, 79.
Bosons are non-matter particles which are force carriers, or messengers that act between matter particles.
The interaction gives rise to three fundamental forces -- the strong force, the weak force and the electromagnatic force. There is a fourth force, gravity, which is suspected to be caused by a still-to-be found boson named the graviton.
In this file photo, a view of the LHC (large hadron collider) in its tunnel at CERN (European particle physics laboratory) is photographed, near Geneva, Switzerland. (AP Photo)
How Has The Higgs Been Hunted?
The quest for the Higgs has been carried out at colliders: giant machines that smash particles together and sift through the sub-atomic debris that tumbles out. The big daddy of these is the Large Hadron Collider (LHC), operated by the European Organisation for Nuclear Research (CERN) in a ring-shaped tunnel deep underground near Geneva.
Smashups generated at the LHC briefly generate temperatures 100,000 times hotter than the Sun, replicating the conditions that occurred just after the Universe's creation in the "Big Bang" nearly 14 billion years ago.
But these concentrations of energy, while violent, occur only at a tiny scale.
On Wednesday, CERN scientists said they had found a new particle that was "consistent" with the Higgs, but further work was needed to determine what it was.
Why "The God Particle"?
The Higgs has become known as the "God particle," the quip being that, like God, it is extremely powerful, exists everywhere but is hard to find.
In fact, the origin of the name is rather less poetic.
It comes from the title of a book by Nobel physicist Leon Lederman whose draft title was "The Goddamn Particle," to describe the frustrations of trying to nail the Higgs.
The title was cut back to "The God Particle" by his publisher, apparently fearful that "Goddamn" could be offensive.
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