Posts Tagged ‘CERN’

God Particle Found?

July 2, 2012
Large Hadron Collider quadrupole magnets for d...

Large Hadron Collider quadrupole magnets for directing proton beams to interact. These superconducting quadrupole electromagnetas were made in Fermilab. (Photo credit: Wikipedia)

Well, maybe. According to the AP, physicists working at the Large Hadron Collider are expected to announce that they have found convincing evidence for the existence of the Higgs Boson, or the “God Particle”. If their observations are confirmed, than this could be the biggest discovery in physics in decades. Here is part of the story.

Scientists believe the “God particle” that might explain the underpinnings of the universe is real, and they are about to present their evidence to the world.

Physicists at the world’s biggest atom smasher plan to announce Wednesday that they have nearly confirmed the primary plank of a theory that could shape the scientific understanding of all matter.

The idea is much like gravity and Isaac Newton’s discovery: It was there all the time before Newton explained it. But now scientists know what it is and can put that knowledge to further use.

The focus of the excitement is the Higgs boson, a subatomic particle that, if confirmed, could help explain why matter has mass, which combines with gravity to give an object weight.

Researchers at the European Organization for Nuclear Research, or CERN, say that they have compiled vast amounts of data that show the footprint and shadow of the particle – all but proving it exists, even though it has never actually been glimpsed.

But two independent teams of physicists are cautious after decades of work and billions of dollars spent. They don’t plan to use the word “discovery.” They say they will come as close as possible to a “eureka” announcement without uttering a pronouncement as if from the scientific mountaintop.

“I agree that any reasonable outside observer would say, `It looks like a discovery,’” said British theoretical physicist John Ellis, a professor at King’s College London who has worked at CERN since the 1970s. “We’ve discovered something which is consistent with being a Higgs.”

CERN’s atom smasher, the $10 billion Large Hadron Collider on the Swiss-French border, has been creating high-energy collisions of protons to investigate dark matter, antimatter and the creation of the universe, which many theorize occurred in a massive explosion known as the Big Bang.

The phrase “God particle,” coined by Nobel Prize-winning physicist Leon Lederman, is used by laymen, not physicists, more as an explanation for how the subatomic universe works than how it all started.

I really wish that they wouldn’t refer to the Higgs Boson as the God particle. Unless someone is planning to start a new religion that worships sub-atomic particles, it is neither an accurate nor appropriate term. Also, the writers of this article really should know better than to refer to the Large Hadron Collider as an “atom smasher”. The LHC is a particle accelerator. Writing atom smasher sounds as if they don’t know much about the subject they are writing about.

One possible way the Higgs boson might be prod...

One possible way the Higgs boson might be produced at the Large Hadron Collider. Similar images at: http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/Conferences/2003/aspen-03_dam.ppt (Photo credit: Wikipedia)

You can find up to date and accurate information from  physicist Matt Strassler at Of Particular Significance.

Shape Shifting Neutrinos

June 11, 2012

I’ll follow that last post with some real science. Last year ,the whole scientific community was excited over the possibility that neutrinos could possibly travel faster than light. Unfortunately, that doesn’t seem to be the case. This was finally confirmed by studies by the OPERA team at CERN, as I read in this article in New Scientist.

The faster-than-light neutrino saga is officially over. Today, at the Neutrino 2012 conference in Kyoto, Japan, the OPERA collaboration announced that according to their latest measurements, neutrinos travel at almost exactly the speed of light.

“Although this result isn’t as exciting as some would have liked, it is what we all expected deep down,” said CERN research director Sergio Bertolucci in a statement.

Even though they do not travel faster than light, neutrinos are still interesting little particles. There are three different types, each associated with a lepton particle; electron neutrinos, muon neutrinos, and tau neutrinos. But the odd thing is that a neutrino can actually change its type or oscillates between the three types. Confirming this oscillation, is in fact, the real job of the OPERA team.

With the dust settling, OPERA is getting back to its real job: finding tau neutrinos. This week the team also announced that they have found the second-ever instance of a muon neutrino morphing into a tau neutrino, strengthening the case that neutrinos have mass.

But all of that was a sidebar to the experiment’s real goal: catching shape-shifting neutrinos in the act. Neutrinos come in three flavours: electron, muon and tau. Several experiments had seen evidence for neutrinos spontaneously switching, or oscillating, from one type to another. Those oscillations proved, to many physicists’ surprise, that the supposed massless particles must have some infinitesimal mass, and offered a route to explaining why there is more matter than anti-matter in the universe.

Before OPERA, all the evidence for neutrino oscillations came from disappearances: detectors would end up with less of a certain type of neutrino than they started with, suggesting some had morphed into other flavours. Then in 2010, OPERA found the first tau neutrino in a beam of billions of muon neutrinos streaming to the Gran Sasso detectors from CERN. The discovery was a big deal at the time, but the team said they needed more tau neutrinos to make it statistically significant.

Now, a second tau neutrino has shown up in the detectors, they report.

“This result shows that the collaboration is definitely and effectively back to its original goal of discovering neutrino oscillations in appearance mode,” De Lellis says.

OPERA will need at least six tau neutrinos to definitively claim they’re seeing the oscillation effect, so they’re not there yet. And when they do, they may find they’ve been scooped: in another experiment, the team behind the T2K detector in Japan announced this week that they have seen 10 muon neutrinos shifting into electron neutrinos.

The idea of neutrino oscillation is not a new one. Scientists first suspected this might be the case when only about one third the expected number of electron neutrinos were detected from the sun. It seemed as though something was badly wrong about our understanding of solar physics. But, if neutrinos have mass, they were believe to be massless at the time, and they could oscillate between the three types, than we would only detect about one third of the expected number from the sun. Detecting the oscillation would also confirm that neutrinos have mass and would be an important step in confirming the standard model of particle physics.

Scientists on Track of the Elusive God Particle

December 17, 2011

Here is some exciting news from the world of particle physics. I wrote about this once before and it seems that they have made some progress.

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.”

Is it just me, or does the beginning of the article sound like they are on the trail of some obscure species of squirrel? Kind of like a hunting magazine?

Tally-ho!! We've got that higgs boson cornered!!!

Or maybe like something from Croc Hunter.

“Crikey!! Today mate, we are on the trail of the elusive higgs boson! It’s hard to find because nobody knows exactly what its mass is!?

Large Hadron Collider Physicist tackles Higgs boson

I really miss that show. Okay, I’m being silly. Here is a bit more from that article.

The Higgs boson is thought to be tied to a field (the Higgs field) that is responsible for giving all other particles their mass. Ironically, physicists don’t have a specific prediction for the mass of the Higgs boson itself, so they must search a wide range of possible masses for signs of the particle.

Based on data collected at LHC’s CMS and ATLAS experiments, researchers said they are now able to narrow down the Higgs’ mass to a small range, and exclude a wide swath of possibilities.

“With the data from this year we’ve ruled out a lot of masses, and now we’re just left with this tiny window, in this region that is probably the most interesting,” said Jonas Strandberg, a researcher at CERN working on the ATLAS experiment.

The researchers have now cornered the Higgs mass in the range between 114.4 and 131 gigaelectronvolts (GeV).For comparison, a proton weighs 1 GeV. Outside that range, the scientists are more than 95 percent confident that the Higgs cannot exist.

Within that range, the ATLAS findings show some indications of a possible signal from the Higgs boson at 126 GeV, though the data are not strong enough for scientists to claim a finding with the level of confidence they require for a true discovery.

“Based on the predicted size of the signal, the experiments may have their first glimpse of a positive signal,” University of Chicago physicist Jim Pilcher wrote in an email to LiveScience. “It is especially important to compare the results of two independent experiments to help reduce statistical fluctuations and experimental biases.”

But it shouldn’t be much longer before scientists can be sure if the Higgs exists, and if so, how much mass it has.

“We know we must be getting close,” Strandberg told LiveScience. “All we need is a little bit more data. I think the data we take in 2012 should be able to really give a definitive answer if the Higgs boson exists.”

I hope they will have a definite answer soon and they win the Nobel Prize.

For more information, here is a blog by a real scientist. I believe that he has just attended a conference where they discussed their latest results.

 

Scientists Try to Explain the Fast-than-light Nutrinos

October 18, 2011

Since the apparent discovery of neutrinos that are moving at superluminal speeds, scientists have been trying to come up with explanations for these findings. The most obvious and likely explanation is measurement error.

Among the most recent ideas is a paper invoking Einstein’s supposedly challenged theory of relativity. The OPERA team used GPS satellites to accurately measure the 730-km distance between their detector and the CERN beam where the neutrinos were produced. Yet, according to special relativity, calculations will be slightly different when two observers are moving relative to one another.

Since the satellites were zipping around the Earth, the positions of the neutrino source and the detector changed. According to the paper, the movement would account for a 64 nanoseconds discrepancy, nearly exactly what the OPERA team observes.

A less likely explanation is that Einstein’s Theory of Relativity is wrong. In fact, both the theories of Special and General Relativity have been amply proved by experiments and observations. There is at least one good reason to suspect that neutrinos do not regularly travel faster than light.

One of the earliest objections to the faster-than-light interpretation came from an astrophysical observation. In 1987, a powerful supernova showered Earth with light and neutrinos. While neutrino detectors observed neutrinos arriving about three hours before the light, this was due to the lightweight particles getting a head start. Neutrinos, which hardly interact with matter, escaped the exploding stellar core with relative ease while photons, absorbed and re-emitted by the various elements, took longer to flee. If the effect from OPERA were as large as observed, scientists have calculated that the neutrinos should have arrived more than four years in advance of the light.

And we know that electrons do not travel faster than light.

Theoretical physicist Matt Strassler also noted on his blog that the Standard Model’s properties suggest that making neutrinos go faster than light requires electrons to do the same. But if electron neutrinos moved at the speed suggested by the OPERA experiment, then electrons should also travel faster than the speed of light by at least one part in 1,000,000,000, or one billionth. Experiments have established theoretical limits that electrons remain subluminal at a precision down to more than 5 part in a thousand trillion, effectively ruling this scenario out.

So, what is going on? We don’t know, yet. My opinion, which really isn’t worth much, is that if the observations are verified, than superluminal travel will be due to some unique property of the nutrinos, which are odd little particles anyway.

I suppose the consensus is measurement error. Too bad. No warp drive yet.

Faster Than Light 2

September 26, 2011
Cropped image from a larger one of Michio Kaku...

Michio Kaku

In an article in the Wall Street Journal, physicist Michio Kaku has something interesting to say about the recent experiments at CERN in which neutrinos seemed to have traveled faster than light.

The CERN announcement was electrifying. Some physicists burst out with glee, because it meant that the door was opening to new physics (and more Nobel Prizes). New, daring theories would need to be proposed to explain this result. Others broke out in a cold sweat, realizing that the entire foundation of modern physics might have to be revised. Every textbook would have to be rewritten, every experiment recalibrated.

Cosmology, the very way we think of space, would be forever altered. The distance to the stars and galaxies and the age of the universe (13.7 billion years) would be thrown in doubt. Even the expanding universe theory, the Big Bang theory, and black holes would have to be re-examined.

Moreover, everything we think we understand about nuclear physics would need to be reassessed. Every school kid knows Einstein’s famous equation E=MC2, where a small amount of mass M can create a vast amount of energy E, because the speed of light C squared is such a huge number. But if C is off, it means that all nuclear physics has to be recalibrated. Nuclear weapons, nuclear medicine and radioactive dating would be affected because all nuclear reactions are based on Einstein’s relation between matter and energy.

If all this wasn’t bad enough, it would also mean that the fundamental principles of physics are incorrect. Modern physics is based on two theories, relativity and the quantum theory, so half of modern physics would have to be replaced by a new theory. My own field, string theory, is no exception. Personally, I would have to revise all my theories because relativity is built into string theory from the very beginning.

In other words, much of what we think we know about the universe is about as accurate as views of the people back in the middle ages who believed that the Earth was the center of the universe and everything was made up of the four elements; earth, fire, air and water. Of course, the most likely outcome is that the findings at CERN are erroneous. Kaku ends his piece by declaring this to be a victory for science however it turns out.

Reputations may rise and fall. But in the end, this is a victory for science. No theory is carved in stone. Science is merciless when it comes to testing all theories over and over, at any time, in any place. Unlike religion or politics, science is ultimately decided by experiments, done repeatedly in every form. There are no sacred cows. In science, 100 authorities count for nothing. Experiment counts for everything.

So, if a theory as well established as Einstein’s Theories of Relativity can be cast into doubt, what does this say about hypotheses regarding global warming, which are based on very incomplete understandings of the Earth’s atmosphere?

I want everyone out there who believes that global warming/climate change/ climate catastrophe is settled science to repeat after me one hundred times. The science is never settled.

You can find Michio Kaku’s books here.

Faster Than Light

September 23, 2011
Tachyon visualization. Since that object moves...

Image via Wikipedia

It would seem that the physicists at CERN have detected subatomic particles moving faster than  the speed of light. This is impossible, according to Einstein’s theory of relativity. So, either we’re about to see a revolution in the way we see the universe or there is a mistake.

A meeting at Cern, the world’s largest physics lab, has addressed results that suggest subatomic particles have gone faster than the speed of light.

The team presented its work so other scientists can determine if the approach contains any mistakes.

If it does not, one of the pillars of modern science will come tumbling down.

Antonio Ereditato added “words of caution” to his Cern presentation because of the “potentially great impact on physics” of the result.

The speed of light is widely held to be the Universe’s ultimate speed limit, and much of modern physics – as laid out in part by Albert Einstein in his theory of special relativity – depends on the idea that nothing can exceed it.

Neutrinos come in a number of types, and have recently been seen to switch spontaneously from one type to another.

The Cern team prepares a beam of just one type, muon neutrinos, and sends them through the Earth to an underground laboratory at Gran Sasso in Italy to see how many show up as a different type, tau neutrinos.

In the course of doing the experiments, the researchers noticed that the particles showed up 60 billionths of a second earlier than they would have done if they had travelled at the speed of light.

This is a tiny fractional change – just 20 parts in a million – but one that occurs consistently.

The team measured the travel times of neutrino bunches some 16,000 times, and have reached a level of statistical significance that in scientific circles would count as a formal discovery.

There is good reason to believe that the speed of light is the ultimate speed limit. As any object moves faster, it gains mass. We don’t notice this because, at the speeds we move the gain is too small to be detected. As you approach the speed of light, the gain in mass is larger and larger. In order to achieve light speed the mass would increase to infinite. This is obviously impossible. This gain in mass has been detected in subatomic particles that have been accelerated to 99.99999% of the speed of light.

Scientists have speculated on particles that move faster than light called tachyons. These particles would be unable to slow down to the speed of light. Tachyons have never been detected (how would you?) and there is no good reason to suppose they exist.

But, here’s something I saw in the wikipedia article on tachyons that seems to have some relevance to this story.

In 1985 it was proposed by Chodos et al. that neutrinos can have a tachyonic nature.[7][8] Today, the possibility of having standard particles moving at superluminal speeds is a natural consequence of unconventional dispersion relations that appear in the Standard-Model Extension,[9][10][11] a realistic description of the possible violation of Lorentz invariance in field theory. In this framework, neutrinos experience Lorentz-violating oscillations and can travel faster than light at high energies.

I am going to have to work on translating that to English. Maybe this article will help.

Most likely this will turn out to be an error in measurement and I have to commend the scientists for their caution. If this turns out to be valid than maybe something like warp drive is not too far away.

Maybe not

Anti-matter

June 7, 2011

Anti-matter is sort of the opposite of regular matter we see  and interact with, except that the particles that make it up are opposite in charge. An anti-electron or positron is positive instead of negative and an anti-proton is negative instead of positive. Neutral particles such as a neutron also have an anti-particle with opposite properties such as baryon number. It i possible to combine anti-protons and anti-neutrons to form the nuclei of anti-atoms and even to get positrons to orbit around these nuclei, forming anti-atoms. Physicists have managed to create anti-hydrogen, but no anti-matter can exist for very long since it is destroyed on contact with matter.

At CERN in Geneva, scientists have managed to capture anti-hydrogen anti-atoms for an incredible 16 minutes. This may not seem very long, but on the scale of atoms and particles, this is an eternity.

“We’ve trapped antihydrogen atoms for as long as 1,000 seconds, which is forever” in the world of high-energy particle physics, said Joel Fajans, a University of California, Berkeley professor of physics who is a faculty scientist at California’s Lawrence Berkeley National Laboratory and a member of the ALPHA (Antihydrogen Laser Physics Apparatus) experiment at CERN.

Trapping antimatter is difficult, because when it comes into contact with matter, the two annihilate each other. So a container for antimatter can’t be made of regular matter, but is usually formed with magnetic fields.

In the ALPHA project, the researchers captured antihydrogen by mixing antiprotons with positrons — antielectrons — in a vacuum chamber, where they combine into antihydrogen atoms.

The whole process occurred within a magnetic “bottle” that takes advantage of the magnetic properties of the antiatoms to keep them contained. An actual bottle, made of ordinary matter, would not be able to hold antimatter because when the two types of matter meet they annihilate.

After the researchers had trapped antimatter in the magnetic bottle, they could then detect the trapped antiatoms by turning off the magnetic field and allowing the particles to annihiliate with normal matter, which creates a flash of light.

The team has now managed to capture 112 antiatoms in this new trap for times ranging from one-fifth of a second to 1,000 seconds, or 16 minutes and 40 seconds. (To date, since the beginning of the project, Fajans and his colleagues have trapped 309 antihydrogen atoms in various traps.)

And the researchers plan to improve on that, with the “hope that by 2012 we will have a new trap with laser access to allow spectroscopic experiments on the antiatoms,” Fajans said in a statement. Those experiments would give researchers more information on the antimatter’s properties.

In that way, it could help to answer a question that has long plagued physicists: Why is there only ordinary matter in our universe? Scientists think antimatter and matter should have been produced in equal amounts during the Big Bang that created the universe 13.6 billion years ago.

Maybe an anti-matter drive, like in Star Trek is just around the corner.

Oh, and see here for the coolest little particles in nature.


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