Brian Cox: What really goes on at the Large Hadron Collider

Large Hadron Collider powers up to unravel mysteries of nature


On Monday, the CERN Control Center turned on the LHC beams to begin the next two-year run of the particle collider. CERN directors decided to extend the run through the end of 2012, instead of shutting down in 2011 for repairs as previously planned, and spirits are running high among scientists working in the field of new physics.

Researchers from across the world engineer detectors and seek to solve the mysteries of matter in an international collaboration that reaches from Chicago to Mumbai.


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Higgs signal sinks from view


The Higgs boson, the most sought-after particle in all of physics, is proving tougher to find than physicists had hoped.

Last month, a flurry of 'excess events' hinted that the Higgs could be popping up inside the Large Hadron Collider (LHC), the world's most powerful particle accelerator located at CERN, Europe's high-energy physics lab near Geneva, Switzerland. But new data presented today at the Lepton Photon conference in Mumbai, India, show the signal fading. It means that "this excess is probably just a statistical fluctuation", says Adam Falkowski, a theorist at the University of Paris-South in Orsay, France.

"There's still certainly plenty of room for a Higgs to be hiding in there," says Hawkings [Richard Hawkings, deputy physics coordinator at ATLAS]. Many physicists believe that the Higgs, if it exists, is likely to be at the lower mass end of the energy spectrum, perhaps between about 120 and 140 GeV. Those lower energy ranges will require more data to find a signal. It may be possible to rule out the Higgs in these regions by the end of the year, but confirmation of a discovery, which requires more data, will probably have to wait until the end of 2012.


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'Observation' of God particle expected at CERN tomorrow - scientists


Scientists with close contacts inside CERN predicted this weekend that sighting of the first strong signs of a particle vital to support Einstein’s ideas of the universe will be reported on Tuesday by the CERN.

They warned that there would be no announcement of a full scientific discovery - but even confirmation that something like the long-sought Higgs boson had been spotted would be a major advance. The particle is believed to have given shape to the universe after the Big Bang 13.7 billion years ago.

Professor John Ellis, a former head of theoretical physics at CERN, told the BBC that he expects to see the first glimpse of the God particle this week.

He said: There seem to be some hints emerging there… and that's what we're going to learn on Tuesday. The veracity of the results has been ensured by two separate teams, each comprising of hundreds of researchers, searching using different experiments.


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Long-Sought 'God Particle' Cornered, Scientists Say


Physicists are closer than ever to hunting down the elusive Higgs boson particle, the missing piece of the governing theory of the universe's tiniest building blocks.

Scientists at the world's largest particle accelerator, the Large Hadron Collider at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, announced today (Dec. 13) that they'd narrowed down the list of possible hiding spots for the Higgs, (also called the God particle) and even see some indications that they're hot on its trail.

I think we are getting very close, said Vivek Sharma, a physicist at the University of California, San Diego, and the leader of the Higgs search at LHC's CMS experiment. We may be getting the first tantalizing hints, but it's a whiff, it's a smell, it's not quite the whole thing.

Today's announcement was highly anticipated by both the physics community and the public, with speculation running rampant in the days leading up to it that the elusive particle may have finally been found. Though the news is not the final answer some were hoping for, the progress is a significant, exciting step, physicists say. [Top 5 Implications of Finding the Higgs Boson]


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Making Sense of CERN’s Higgs Circus


At the low end of the energy spectrum, at around 120 GeV (a region of energy that attracted less attention because it had been well within the reach of Fermilab’s now-defunct Tevatron accelerator) there was a slight bump in the data, barely breaching the two-sigma (two standard deviations) bounds–which is something that happens by chance alone about once in twenty times (two-sigma bounds go with 95% probability, hence a one-in-twenty event is allowable as a fluke in the data). But since the summer, data has doubled: twice as many collision events had been recorded as had been by the time the Mumbai conference had taken place. And, lo and behold: the bump still remained!

This gave the CERN physicists the idea that perhaps that original bump was not a one-in-twenty fluke that happens by chance after all, but perhaps something far more significant. Two additional factors came into play as well: the new anomaly in the data at roughly 120 GeV was found by both competing groups at CERN: the CMS detector, and the ATLAS detector; and–equally important–when the range of energy is pre-specified, the statistical significance of the finding suddenly jumps from two-sigma to three-and-a-half-sigma!

This means that if you pre-specify that the Higgs must be light (in the low end of the energy spectrum, as, in fact, the Standard Model indicates), the chance that the data bump is a fluke quickly goes down to 1 in 5,000, and the probability that the Higgs boson actually exists jumps from a little over 95% to more than 99.98%–an excellent probability. By convention, however, physicists demand a five-sigma level of proof for all particle discoveries, which means a probability of 99.99997%. Such strict standards of proof would require a lot more data. So, at present, we have only hints of a Higgs and we are still waiting for the final, five-sigma word on the Higgs’ existence.


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Professor Ed Copeland shows us inside the CMS Experiment at the Large Hadron Collider - will it find the elusive Higgs Boson? We'll be uploading another film from the sister experiment ATLAS very soon!

Scientists raise energy level at LHC


Researchers at the European Organization for Nuclear Research, or CERN, say the $10 billion Large Hadron Collider in a 27-kilometer (17-mile) tunnel under the Swiss-French border at Geneva has begun operating at 8 trillion electron volts, greater than any previous physics accelerator.

Steve Myers, a director of accelerators and technology at CERN, said in a statement that two proton beams were brought into collision at a new world record energy level Thursday.

He says it marks a new round of data collection through the remainder of the year, and increased discovery potential.


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This Just In: Brainless Boson Outwits Scientists


To date, however, the Higgs boson remains as elusive as ever. Moreover, I feel compelled to ask: What will the media say if the summer passes and the Higgs boson still refuses to reveal itself? And then the winter, followed by another year of near misses? Will its discovery still be "excruciatingly" close? Or will a science journalist simply whip out his thesaurus to find a more compelling adverb? "Extra super double plus agonizingly excruciatingly" comes to mind.

Here's an idea the science media seem to neglect altogether: the failure to find the Higgs boson may indicate a serious flaw in our formulation of the Standard Model. The issue has never been that the Higgs boson must exist, but that it must exist if the Standard Model is at all true. The Standard Model, in turn, is true only if Big Bang Cosmology is real. This leaves the scientist with only two options: find that damn Higgs boson, or reformulate the Standard Model by finding other options than the Big Bang, maybe even toss it out altogether.

To insist that the former option, for the sake of the latter, must be realized puts the particle physicist in an unfortunate position -- rather like a child trying to pound a piece of jigsaw puzzle into place when it may fit elsewhere.

The lesson: For all our confidence in science, we have to remember first and foremost that science is a human endeavor. All human beings, without exception, are flawed; therefore, any human endeavor will be flawed as well.

And maybe that's why we can't find the Higgs boson.


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How the Discovery of the Higgs Boson Could Break Physics


If gossip on various physics blogs pans out, the biggest moment for physics in nearly two decades is just days away. The possible announcement on July 4 of the long-sought Higgs boson would put the last critical piece of the Standard Model of Physics in place, a crowning achievement built on a half-century of work by thousands of scientists. A moment worthy of fireworks.

The tricky part is that the LHC, in addition to searching for the Higgs, has also been looking for these heavy supersymmetric superpartners. But thus far, nothing is showing up. Furthermore, all indications are that scientists will find that the Higgs weighs 125 gigaelectronvolts (GeV) – or about 125 times more than a proton – which means that it sits exactly where the Standard Model expected it to be.

Great news for the troublesome Standard Model, not so much for its savior, supersymmetry.

Supersymmetry was first proposed in the 1960s and developed seriously during the heyday of particle physics in the 1970s and ‘80s. Back then, large particle accelerators were smashing subatomic particles together and discovering a slew of new bits and pieces, including quarks and the W and Z bosons. Supersymmetry was put forth as an extension of the Standard Model, but the predicted particles were out of reach for atom smashers of that era.

Before the LHC was up and running in 2010, many physicists were hopeful that it would uncover some evidence for supersymmetry. Despite a few promising results, experimental confirmation of the idea keeps failing to show up.

This has a few in the community beginning to seriously doubt their darling supersymmetry will ever be a viable theory.

It’s a beautiful theory, and I would love it if it were true, said particle physicist Tommaso Dorigo, who works on one of the LHC’s two main experiments. But there is not any compelling evidence.


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The Higgs Boson: Particle of the Year

Forget Person of the Year -- the discovery this summer by the Large Hadron Collider of the Higgs Boson particle was one of science's greatest achievements

2012 Breakthrough of the Year: The Higgs Boson

Exotic particles made headlines again and again in 2012, making it no surprise that the breakthrough of the year is a big physics finding: confirmation of the existence of the Higgs Boson. Hypothesized more than 40 years ago, the elusive particle completes the standard model of physics, and is arguably the key to the explanation of how other fundamental particles obtain mass. In this video, Science News Writer Adrian Cho talks about this momentous finding and what physicists will do next.