Interesting results from CERN's LHC

[Viking]

http://www.nature.com/news/2011/220911/full/news.2011.554.html

Published online 22 September 2011 | Nature | doi:10.1038/news.2011.554

News
Particles break light-speed limit

Neutrino results challenge cornerstone of modern physics.

Geoff Brumfiel

An Italian experiment has unveiled evidence that fundamental particles known as neutrinos can travel faster than light. Other researchers are cautious about the result, but if it stands further scrutiny, the finding would overturn the most fundamental rule of modern physics — that nothing travels faster than 299,792,458 metres per second.

The experiment is called OPERA (Oscillation Project with Emulsion-tRacking Apparatus), and lies 1,400 metres underground in the Gran Sasso National Laboratory in Italy. It is designed to study a beam of neutrinos coming from CERN, Europe's premier high-energy physics laboratory located 730 kilometres away near Geneva, Switzerland. Neutrinos are fundamental particles that are electrically neutral, rarely interact with other matter, and have a vanishingly small mass. But they are all around us — the Sun produces so many neutrinos as a by-product of nuclear reactions that many billions pass through your eye every second.

The 1,800-tonne OPERA detector is a complex array of electronics and photographic emulsion plates, but the new result is simple — the neutrinos are arriving 60 nanoseconds faster than the speed of light allows. "We are shocked," says Antonio Ereditato, a physicist at the University of Bern in Switzerland and OPERA's spokesman.
Breaking the law

The idea that nothing can travel faster than light in a vacuum is the cornerstone of Albert Einstein's special theory of relativity, which itself forms the foundation of modern physics. If neutrinos are travelling faster than light speed, then one of the most fundamental assumptions of science — that the rules of physics are the same for all observers — would be invalidated. "If it's true, then it's truly extraordinary," says John Ellis, a theoretical physicist at CERN.

Ereditato says that he is confident enough in the new result to make it public. The researchers claim to have measured the 730-kilometre trip between CERN and its detector to within 20 centimetres. They can measure the time of the trip to within 10 nanoseconds, and they have seen the effect in more than 16,000 events measured over the past two years. Given all this, they believe the result has a significance of six-sigma — the physicists' way of saying it is certainly correct. The group will present their results tomorrow at CERN, and a preprint of their results will be posted on the physics website ArXiv.org.

At least one other experiment has seen a similar effect before, albeit with a much lower confidence level. In 2007, the Main Injector Neutrino Oscillation Search (MINOS) experiment in Minnesota saw neutrinos from the particle-physics facility Fermilab in Illinois arriving slightly ahead of schedule. At the time, the MINOS team downplayed the result, in part because there was too much uncertainty in the detector's exact position to be sure of its significance, says Jenny Thomas, a spokeswoman for the experiment. Thomas says that MINOS was already planning more accurate follow-up experiments before the latest OPERA result. "I'm hoping that we could get that going and make a measurement in a year or two," she says.
Reasonable doubt

If MINOS were to confirm OPERA's find, the consequences would be enormous. "If you give up the speed of light, then the construction of special relativity falls down," says Antonino Zichichi, a theoretical physicist and emeritus professor at the University of Bologna, Italy. Zichichi speculates that the 'superluminal' neutrinos detected by OPERA could be slipping through extra dimensions in space, as predicted by theories such as string theory.

Ellis, however, remains sceptical. Many experiments have looked for particles travelling faster than light speed in the past and have come up empty-handed, he says. Most troubling for OPERA is a separate analysis of a pulse of neutrinos from a nearby supernova known as 1987a. If the speeds seen by OPERA were achievable by all neutrinos, then the pulse from the supernova would have shown up years earlier than the exploding star's flash of light; instead, they arrived within hours of each other. "It's difficult to reconcile with what OPERA is seeing," Ellis says.

Ereditato says that he welcomes scepticism from outsiders, but adds that the researchers have been unable to find any other explanation for their remarkable result. "Whenever you are in these conditions, then you have to go to the community," he says.

[Neil]

Prepare for an onslaught of crazy Christians attacking science based on the changing data, especially as it applies to c and radiometric dating.

[Ideologue]

I wonder what the LHC uses to detect neutrinos.

This thing.

Super-K looks a lot cooler and sciency.

[Neil]

That's a lot smaller than the older detectors.  This is a fine future we live in.

[Ideologue]

Well, it's built to detect particle collision-resultant neutrinos from Cern.  I don't think it can reliably detect, say, solar or cosmic ray neutrinos (maybe it can, I'm not sure).  Ice Cube, by contrast, is huge, at least in the sense that it utilizes a very large volume of preexisting transparent ice.  Still pretty cool, yeah.

All I'm saying is that if I were going to set a movie or a comic book in a neutrino detector, I'd film at or draw the Mt. Kamioka facility.



That's cinematic right there.  As opposed to the stockroom in a grocery store look of OPERA.

[Warspite]

The bartender says, 'I'm sorry, we don't serve neutrinos in here'. A neutrino walks into a bar.

[crazy canuck]

The bartender says, 'I'm sorry, we don't serve neutrinos in here'. A neutrino walks into a bar.

[Martinus]

The bartender says, 'I'm sorry, we don't serve neutrinos in here'. A neutrino walks into a bar.

[Razgovory]

More on the story.

Test confirms particles appear to travel faster than the speed of light

(CNN) – Travel faster than the speed of light? Really?

Back in September, scientists found that tiny particles called neutrinos appeared to do just that, defying Einstein's special theory of relativity.

It could be a fluke, but now the same experiment has replicated the result. It's not hard proof yet, though; other groups still need to confirm these findings.

Physicists with the OPERA (Oscillation Project with Emulsion-tRacking Apparatus) experiment said in September that neutrinos sent about 454 miles (730 kilometers) from CERN in Switzerland arrived at Italy's Gran Sasso National Laboratory a fraction of a second sooner than they should have according to Einstein's theory.

Other scientists were skeptical, raising questions about possible flaws in the study.

So OPERA scientists rechecked parts of the experiment to take into account suggestions from their critics. They announced Friday that the new test confirms the initial findings.

"This result confirms that neutrinos arrived at Gran Sasso lab 62.1 nanoseconds in advance with respect to the time computed assuming the speed of light in vacuum," according to Lucia Votano, director of INFN-Gran Sasso Laboratory.

The OPERA team's initial result was based on observing more than 15,000 bunches of neutrinos, or electrically neutral subatomic particles. But the scientists did not track any one specific neutrino. Instead, the neutrinos were produced in long pulses that lasted about 10 millionths of a second.

"Although this sounds short, it is hundreds of times longer than the 60 nanoseconds early arrival time of the neutrinos at the Gran Sasso in Italy," said Andy Cohen, a professor of physics at Boston University, who is not involved in OPERA.

This means that when a neutrino arrived at Gran Sasso there was no way to know exactly when it was produced during the pulse, preventing an accurate measurement of its speed.

The new study used shorter pulses making it easier to know more precisely when an individual neutrino was generated.

"They did this for only 20 neutrinos," Cohen said, "but since the speed of each one is known, this leads to a very precise result, confirming that the neutrinos appear to be arriving 60 nanoseconds earlier than expected."

But don't throw your physics book just yet. Cohen said there are other potential issues with the experiment that haven't been addressed yet. "While this result is a very significant improvement over the previous measurement, many of the concerns that have been raised about possible sources of uncertainty remain.

"We should probably remain skeptical until we have confirmation from other experiments," he said.

Votana agrees and said the OPERA measurement needs to be confirmed by independent scientists. Even if the results are confirmed, we won't toss out all of Einstein's theory. A broader theory would be generated that would include Einstein's theory, Votana said.

Scientists at Fermilab in Illinois and in Japan are expected to try to replicate the findings.

"If the neutrinos are truly traveling faster than light this would require profound changes in the way we understand space and time," Cohen said

[Siege]

I want to learn how to bend reality.

[Darth Wagtaros]

I want to learn how to bend reality.

Easy enough. Just remember: there is no spoon.

[Siege]

I want to learn how to bend reality.

Easy enough. Just remember: there is no spoon.

Drunk boy: Do not try and drink the beer. That's impossible. Instead... only try to realize the truth.
Neo: What truth?
Drunk boy: There is no beer in the bottle.
Neo: There is no beer in the bottle?
Drunk boy: Then you'll see, that it is not the beer what you drink, it is only yourself.

[Drakken]

The bartender says, 'I'm sorry, we don't serve neutrinos in here'. A neutrino walks into a bar.

A neutrino enters a bar and asks how much they charge for a drink there. The bartender's answer, "For you, my friend, no charge".