Hadron Collider Update

CERN Discovers A New Particle, Likely The Higgs Boson
July 4, 2012
by Eyder Peralta - NPR

The Large Hadron Collider.

Two teams of scientists using the Large Hadron Collider at the European Organization for Nuclear Research, or CERN, announced in Geneva this morning that they have detected a new subatomic particle that bears the hallmarks of the elusive and highly sought after Higgs boson. In layman's terms, the Higgs is referred to as the "God Particle" because the field it produces gives atoms their mass. Were it not for the Higgs, the world we know would be completely different — there would be no chemistry, no architecture, no us. It would be a massless mess of aimless particles running around at light speed.

In a press release, ATLAS experiment spokesperson Fabiola Gianotti said the preliminary results were attained with a "5-sigma signal," which is significant because it sits right at the threshold for what scientists consider a true discovery.

British physicist Peter Higgs, right, arrives for the opening of a seminar to deliver the latest update in the 50-year bid to explain a riddle of fundamental matter in the search for a particle called the Higgs boson.

"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 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."

An undated handout graphic distributed on July 4, 2012 by the European Organization for Nuclear Research (CERN) in Geneva shows a representation of traces of traces of a proton-proton collision measured in the Compact Muon Solenoid (CMS) experience in the search for the Higgs boson.

To make the observations, scientists at the LHC sent particles crashing at tremendous speeds to try to create Higgs. Then, because the particle only exists for a billionth of a billionth of a billionth of a second, scientists looked for its signature decay. The scientists said they had detected what are likely Higgs trails — a bump in their data — with a great degree of certainty.

The announcement is one of the biggest scientific breakthroughs in decades and could put the finishing touches on Standard Model particle physics.

"It's hard not to get excited by these results," CERN Research Director Sergio Bertolucci said in a statement. "We stated last year that in 2012 we would either find a new Higgs-like particle or exclude the existence of the Standard Model Higgs. With all the necessary caution, it looks to me that we are at a branching point: the observation of this new particle indicates the path for the future towards a more detailed understanding of what we're seeing in the data."

Because it's complicated material, we turned to Adam Frank, an astrophysicist and a blogger for NPR's 13.7. We asked a him a few questions about why this matters. Here's part of our conversation:

Q: I've heard many metaphors for what this Higgs boson is. A basic explanation is that it's the thing that gives subatomic particles their mass. The best metaphor I've heard is from Fermilab's Don Lincoln, who says the energy field made by the Higgs is like water. Depending on your mass you'll move through the water with ease — like a barracuda — or slowly, like a big, fat man. How would you explain the Higgs to a friend at a bar?

A: In a bar, I'd probably use one of those analogies. The real important thing for me is that fundamental particles are as far as we can tell zero-dimensional particles. They have no radius. You can't think of fundamental particles as being glass marbles. They literally have no extension in space. They can never bump into anything else.

It's all about interactions. It's about them exchanging other particles as forces. With a particle like the electron — what gives the electron mass is really inertia, that's the property that we associate with massive particles. Mass and inertia go together.

So since an electron or a quark has no extension in space, you sort of wonder where did the mass go? Well it's not that the mass resides with the electron or the proton. It's that the mass comes from its interaction with other things. And in this case, it's the Higgs field that gives this point particle — the electron — the appearance of inertia. That is what allows it to act like it's resisting changes in its motion.

Whereas you have other particles like the photon which has no mass, and because of that it can go at the speed of light, whereas a massive particle will never be able to go at light speed.

Q: So, if the Higgs didn't exist, what would the world look like?

A: It would all be photons. Everything would be moving at the speed of light, right. Which means at light speed, you wouldn't be able to have the kinds of structures we see today. You'd never get atoms and chemistry and rocks. So it's really important. The property of mass is really important for getting clumpy structures, essentially, like us.

Q: The particle has been described as the missing piece of the Standard Model. Is that a fair characterization?

A: Yeah, pretty much. So the Standard Model is this beautiful edifice of modern particle physics that's really 40 years old. The pieces were really in place 40 years ago and people have just been going around and discovering them.

The theory — the Standard Model predicted all these different pieces 40 years ago — and the quarks were part of it, the different flavors of neutrinos, some have been discovered and essentially the top quark was the last big thing that needed to be discovered and that was discovered in the mid-90s. And the Higgs boson, which was predicted not just by Peter Higgs but six different physicists at the same time, is the last piece of the Standard Model that needs to be discovered, that needs to be shown to be true.

One of the interesting things about this is that for particle physicists, they're in a bit of a conundrum, where they've been working on the Standard Model for all these years. And the Higgs particle is an enormous achievement, but it's also for them a little bit boring because they've been expecting this for 40 years and they keep looking for ways to go beyond the Standard Model.

Q: Another thing I find interesting, though, is that despite this announcement, scientists have never actually seen the Higgs, right?

A: You're never going to get the Higgs to appear in laboratory and float. It's very short-lived. What happens in particle physics is that particles decay into other particles, just like with radioactivity. The Higgs does that but in a very, very, very short time scale — so short that you're never going to be able to see the Higgs directly, you're going to see what it turns into.

And there are a lot of different ways it can turn into other things. There are a lot of different channels. What we're looking for is different possible channels. And that's how they're going to tell if it's a Standard Model Higgs. It'll have a certain kind of decay pathways.

Q: Fermilab, the American organization with much smaller version of the LHC, made a similar announcement on Monday, saying they had identified those decay pathways, except they said they had fallen short of a 3-sigma standard, which determines strong evidence. Can you tells us what that means?

A: A definitive discovery is a 5-sigma result. What do we mean by these sigmas? Really it's all about how sure are we that what you're seeing is not noise, is not just a statistical anomaly.

The higher your sigma, the more statistically you're certain what you're seeing is not just something crazy that's happening in the background.

With the Tevatron, which was Fermilab's particle accelerator, in many ways, scientists hoped they would be able to see evidence of the Higgs. With these particle accelerators, you want to have enough particle collisions that you have lots of statistics and the problem with Tevatron is that even though it ran for a long time, it wasn't powerful enough to create lots and lots of collisions so that they could very quickly see if they were getting a high enough sigma result. Unfortunately the government said, OK we're done with the Tevatron.

But they did have 10 years worth of data to play with, so they did this very deep, very powerful statistical analysis and they found — and they of course announced in on Monday to take a little bit of the thunder from the LHC — this signature of the Higgs.

Q: What's next for physics? What's the next frontier?

A: Astronomy. [Laughs] If they discover the Higgs, there's going to be lots of interesting things to do with trying to make lots of them and probe their properties. They're going to learn a lot from that.

And they're still going to hope they're going to find things that break the Standard Model — new physics they often call it. They're going to find something in the LHC that really looks very different than the Standard Model.

If they can't get beyond the Standard Model that will be a problem for them. If everything they find is in line with the Standard Model, it'll feel like a dead end. If nothing they see goes beyond the Standard Model, they're going to say, "Well nature isn't showing us where do we go from here, so where do we go from here?"

Q: Let's back up a bit. You have a vested interest in saying astronomy. But what do you mean by that?

A: Doing physics in this way — of smashing things together with ever larger machines — we are clearly sort of reaching a limit of how big these machines can get, or what people are willing to fund, let me put it that way.

So in order to go to even higher levels of energy, you know colliding things at an even higher level of energy, you have to rely on nature. You have to look to astrophysical conditions. You have to look at the beginning of the universe and the big bang or the environments around black holes to find enviornments where interactions between particles are so violent that you are getting insights to regimes beyond the Standard Model.

A lot of high energy physicists are looking to astronomy and astrophysics as being their next particle accelerator, you know nature's particle accelerator.

PHOTOS

http://www.npr.org/blogs/thetwo-way/2012/07/04/156221787/cern-says-its-detected-a-new-particle-likely-the-higgs-boson

Eureka!

They say it's gonna change our world, but I am not educated enough to know how or how much.

I'm convinced. I think they found it. Unfortunately, simply finding it doesn't gain us that much information because it just confirms a theory which has been around for 4 decades.

They will need to get a lot more detailed information on the particle in order to fine tune the formula to [hopefully] reveal something really significant that they don't already know (and I'm not sure what that might be).

It's a breakthrough finding, and I applaud them for it. But I feel unsatisfied because in and of itself, it doesn't really tell us much more than we already surmised.

Now the real work begins.

Now the real waiting begins.

New Subatomic Particle May Be Physics' Missing Link
by Richard Harris -NPR All Things Considered
July 4, 2012

Scientists have discovered a new subatomic particle with profound implications for understanding our universe. On Wednesday, they announced they've found a particle believed to be the long-awaited Higgs boson. Nicknamed the "God particle," it represents the final piece in a theory that explains the basic nature of our universe.

Fabiola Gianotti of the ATLAS group (left) and Joe Incandela of the Compact Muon Spectrometer team announced their findings during a presentation Wednesday in Switzerland.

Nothing has been easy in the search for the Higgs particle. It takes a huge amount of energy to create one, something on the scale of the energies that existed in the early moments of the Big Bang. Recreating that level of energy requires smashing particles together in the world's most powerful accelerators. Scientists knew that even if they created a Higgs boson, it would break apart immediately. The only way to identify it would be to sift through that subatomic debris, looking for signs of the decaying Higgs.

But experiments over the past year at CERN's particle accelerator in Switzerland, the Large Hadron Collider, seem to have surmounted all those hurdles. Early Wednesday, Joe Incandela, spokesperson for CERN's Compact Muon Spectrometer (CMS) team stood before a packed auditorium in Switzerland to report the big news — in a way that only geeky physicists could really appreciate.

"In the region of 125 GEV, they combine and give us a combined significance of 5 standard deviations," he said, proving that even momentous discoveries sound dry if you get down far enough into the weeds.

Fabiola Gianotti spoke on behalf of a second huge collaborative experiment, the ATLAS group, which also reported results. The audience didn't even wait for her to speak after she flashed a slide showing that team's statistics.

"I'm not done yet," she told the group. "There's more to come, be patient!"

It's a key to the structure of the universe.

- Joe Incandela, CERN

Through nearly two hours of technical details, the crowd of scientists got what it had come for. In the end, Rolf Heuer, director of the CERN particle accelerator, finally put it in plain language.

"As a layman, I would now say, 'I think we have it,' " he announced. But in almost the same breath, Heuer put his scientist hat back on and started shading his language: "We have observed a new particle consistent with a Higgs boson."

The scientists weren't ready to come right out and say this is the Higgs boson. It's a new particle, to be sure, and one that at first glance looks like the Higgs boson. But is this actually the Higgs boson everyone was expecting or something a bit different?

"That remains open," Heuer said.

He said it could take three or four more years to run the experiments necessary to figure out exactly what they've found. But Higgs or no, the discovery of a new particle is a major deal.

British physicist Peter Higgs (right), who proposed the Higgs boson in the 1960s, speaks with Belgium physicist Francois Englert at Wednesday's event.

"This boson is a very profound thing that we found," said Incandela of the CMS team, putting it in layman's terms after his formal presentation. "This is not like other ordinary particles. We're reaching into the fabric of the universe at a level we've never done before. It's a key to the structure of the universe."

If it is indeed the Higgs boson, the discovery would provide evidence that there's a field — the Higgs field — that permeates our universe and interacts with particles to create mass. It explains why the atoms that make us who we are actually have substance.

"It's a rather profound thing," Incandela said. "That we can maybe answer the question someday: Where does our substance come from — where does mass come from?"

Those deep ideas will be teased out in experiments to be run in the years to come. But Wednesday was a celebration for the entire field of physics. Even Peter Higgs, who proposed the Higgs particle back in the 1960s, was on hand.

"Congratulations to everybody involved in this tremendous achievement," he said. "For me, it's really an incredible thing that it's happened in my lifetime."

Higgs will now wait, along with everyone else, to see whether this new particle really is the one that bears his name.

PHOTOS

http://www.npr.org/2012/07/04/156248281/new-subatomic-particle-may-be-physics-missing-link

Jul. 05, 2012
Higgs boson discovery opens new doors, physics professor says
Tony Adame | McClatchy Newspapers

WICHITA, Kan. -- ]

In the pursuit of seemingly infinite questions, there can only be more understanding.

That was the prevailing sentiment of physicist Nickolas Solomey on Wednesday after the European Center for Nuclear Research - better known as CERN - announced the likely discovery of the Higgs boson, a particle that scientists at the Geneva, Switzerland-based research facility believe could unlock some of the answers to our universe's origin.

The Higgs, which until now had been purely theoretical, is regarded as key to understanding why matter has mass, which combines with gravity to give all objects weight. The particle's existence is considered fundamental to the creation of the universe.

"One question is that now that we know there is this all-permeating Higgs field ... where did it come from?" asked Solomey, the director of physics at Wichita State University since 2007. "How does it act? Maybe once we know that we can start to use it."

Solomey has several close ties to the half-century-long saga that ended Wednesday and began with a theory from Scottish scientist Peter Higgs and others in 1964 that such a particle existed.

The Higgs boson's commonly used nickname in popular culture - the "God particle" - was coined by Solomey's close friend Leon Lederman, in the title of Lederman's popular book on particle physics, "The God Particle: If the Universe Is the Answer, What Is the Question?"

The nickname is cringe-inducing for most scientists because it indicates the particle's discovery might tell us the genesis of creation. Solomey chuckled at its reference on Wednesday. Lederman recruited Solomey away from the University of Chicago to come work at the Illinois Institute of Technology in 1999.

"Leon just needed a catchy title for his book," Solomey said. "I know he regrets it. We've known each other for a long time."

Solomey, a Pittsburgh native, worked at CERN from 1985 to 1992 under Noble Prize winner Georges Charpak and earned his Ph.D. in particle physics from the University of Geneva in 1992.

While at CERN, Charpak and Solomey worked to create high-density states of matters - states that would have been found at the beginning of the "Big Bang" - the cosmological event that explains the early development of the universe.

"We did heavy ion collision," Solomey said. "Trying to create an environment too hot for protons and neutrons. The key to any misconception of our work is that we were creating conditions that were at the beginning of the Big Bang. What we did was so controlled and in such a small space ... you can't release more energy than you put in.

"And we were not generating huge amounts of energy."

The discovery of the Higgs boson at CERN does raise the question: If scientists are creating a particle that professes to be the place where all mass comes from, how can they contain its growth? Does the Higgs boson present any danger to the planet?

"There's no danger because it takes a certain amount of energy to make it and you can't get any more out of it than you put in," Solomey said. "The (particle accelerator) is producing a certain amount of power and it's not like it's uncontrolled or there are an infinite number of (particles).

"It is producing elementary particles, not anywhere near to producing a dangerous amount."

Solomey also stressed that the discovery of the Higgs boson could take a long time to fully understand, comparing it to the discovery of the electron by J.J. Thomson in 1897.

"Imagine that after Thomson discovered the electron, that it took a good 50 to 100 years to learn how to use it, how to manipulate it," Solomey said. "It showed us how to make televisions, how to make transistor radios, how to make medical imaging ... how to sterilize our foods.

"The discovery of the Higgs boson could lead to very new things ... imagine anything that has mass and how it couples to different masses. We could apply these things to new, wonderful technologies. To do things when it's critical to our basic science, our basic survival, always leads to an advance in applications."