New Physics Complications Lend Support to Multiverse Hypothesis

Decades of confounding experiments have physicists considering a startling possibility: The universe might not make sense

Natalie Wolchover and Simons Science News, 06/01/13

From Simons Science News (find original story here)

On an overcast afternoon in late April, physics professors and students crowded into a wood-paneled lecture hall at Columbia University for a talk by Nima Arkani-Hamed, a high-profile theorist visiting from the Institute for Advanced Study in nearby Princeton, N.J. With his dark, shoulder-length hair shoved behind his ears, Arkani-Hamed laid out the dual, seemingly contradictory implications of recent experimental results at the Large Hadron Collider in Europe.

“The universe is inevitable,” he declared. “The universe is impossible.”

The spectacular discovery of the Higgs boson in July 2012 confirmed a nearly 50-year-old theory of how elementary particles acquire mass, which enables them to form big structures such as galaxies and humans. “The fact that it was seen more or less where we expected to find it is a triumph for experiment, it’s a triumph for theory, and it’s an indication that physics works,” Arkani-Hamed told the crowd.

However, in order for the Higgs boson to make sense with the mass (or equivalent energy) it was determined to have, the LHC needed to find a swarm of other particles, too. None turned up.

With the discovery of only one particle, the LHC experiments deepened a profound problem in physics that had been brewing for decades. Modern equations seem to capture reality with breathtaking accuracy, correctly predicting the values of many constants of nature and the existence of particles like the Higgs. Yet a few constants — including the mass of the Higgs boson — are exponentially different from what these trusted laws indicate they should be, in ways that would rule out any chance of life, unless the universe is shaped by inexplicable fine-tunings and cancellations.

In peril is the notion of “naturalness,” Albert Einstein’s dream that the laws of nature are sublimely beautiful, inevitable and self-contained. Without it, physicists face the harsh prospect that those laws are just an arbitrary, messy outcome of random fluctuations in the fabric of space and time.

The LHC will resume smashing protons in 2015 in a last-ditch search for answers. But in papers, talks and interviews, Arkani-Hamed and many other top physicists are already confronting the possibility that the universe might be unnatural. (There is wide disagreement, however, about what it would take to prove it.)

“Ten or 20 years ago, I was a firm believer in naturalness,” said Nathan Seiberg, a theoretical physicist at the Institute, where Einstein taught from 1933 until his death in 1955. “Now I’m not so sure. My hope is there’s still something we haven’t thought about, some other mechanism that would explain all these things. But I don’t see what it could be.”

Physicists reason that if the universe is unnatural, with extremely unlikely fundamental constants that make life possible, then an enormous number of universes must exist for our improbable case to have been realized. Otherwise, why should we be so lucky? Unnaturalness would give a huge lift to the multiverse hypothesis, which holds that our universe is one bubble in an infinite and inaccessible foam. According to a popular but polarizing framework called string theory, the number of possible types of universes that can bubble up in a multiverse is around 10^500. In a few of them, chance cancellations would produce the strange constants we observe.

In such a picture, not everything about this universe is inevitable, rendering it unpredictable. Edward Witten, a string theorist at the Institute, said by email, “I would be happy personally if the multiverse interpretation is not correct, in part because it potentially limits our ability to understand the laws of physics. But none of us were consulted when the universe was created.”

“Some people hate it,” said Raphael Bousso, a physicist at the University of California at Berkeley who helped develop the multiverse scenario. “But I just don’t think we can analyze it on an emotional basis. It’s a logical possibility that is increasingly favored in the absence of naturalness at the LHC.”

What the LHC does or doesn’t discover in its next run is likely to lend support to one of two possibilities: Either we live in an overcomplicated but stand-alone universe, or we inhabit an atypical bubble in a multiverse. “We will be a lot smarter five or 10 years from today because of the LHC,” Seiberg said. “So that’s exciting. This is within reach.”

Cosmic Coincidence

Einstein once wrote that for a scientist, “religious feeling takes the form of a rapturous amazement at the harmony of natural law” and that “this feeling is the guiding principle of his life and work.” Indeed, throughout the 20th century, the deep-seated belief that the laws of nature are harmonious — a belief in “naturalness” — has proven a reliable guide for discovering truth.

“Naturalness has a track record,” Arkani-Hamed said in an interview. In practice, it is the requirement that the physical constants (particle masses and other fixed properties of the universe) emerge directly from the laws of physics, rather than resulting from improbable cancellations. Time and again, whenever a constant appeared fine-tuned, as if its initial value had been magically dialed to offset other effects, physicists suspected they were missing something. They would seek and inevitably find some particle or feature that materially dialed the constant, obviating a fine-tuned cancellation.

This time, the self-healing powers of the universe seem to be failing. The Higgs boson has a mass of 126 giga-electron-volts, but interactions with the other known particles should add about 10,000,000,000,000,000,000 giga-electron-volts to its mass. This implies that the Higgs’ “bare mass,” or starting value before other particles affect it, just so happens to be the negative of that astronomical number, resulting in a near-perfect cancellation that leaves just a hint of Higgs behind: 126 giga-electron-volts.

Physicists have gone through three generations of particle accelerators searching for new particles, posited by a theory called supersymmetry, that would drive the Higgs mass down exactly as much as the known particles drive it up. But so far they’ve come up empty-handed.

The upgraded LHC will explore ever-higher energy scales in its next run, but even if new particles are found, they will almost definitely be too heavy to influence the Higgs mass in quite the right way. The Higgs will still seem at least 10 or 100 times too light. Physicists disagree about whether this is acceptable in a natural, stand-alone universe. “Fine-tuned a little — maybe it just happens,” said Lisa Randall, a professor at Harvard University. But in Arkani-Hamed’s opinion, being “a little bit tuned is like being a little bit pregnant. It just doesn’t exist.”

If no new particles appear and the Higgs remains astronomically fine-tuned, then the multiverse hypothesis will stride into the limelight. “It doesn’t mean it’s right,” said Bousso, a longtime supporter of the multiverse picture, “but it does mean it’s the only game in town.”

A few physicists — notably Joe Lykken of Fermi National Accelerator Laboratory in Batavia, Ill., and Alessandro Strumia of the University of Pisa in Italy — see a third option. They say that physicists might be misgauging the effects of other particles on the Higgs mass and that when calculated differently, its mass appears natural. This “modified naturalness” falters when additional particles, such as the unknown constituents of dark matter, are included in calculations — but the same unorthodox path could yield other ideas. “I don’t want to advocate, but just to discuss the consequences,” Strumia said during a talk earlier this month at Brookhaven National Laboratory.

However, modified naturalness cannot fix an even bigger naturalness problem that exists in physics: The fact that the cosmos wasn’t instantly annihilated by its own energy the moment after the Big Bang.

Dark Dilemma

The energy built into the vacuum of space (known as vacuum energy, dark energy or the cosmological constant) is a baffling trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion times smaller than what is calculated to be its natural, albeit self-destructive, value. No theory exists about what could naturally fix this gargantuan disparity. But it’s clear that the cosmological constant has to be enormously fine-tuned to prevent the universe from rapidly exploding or collapsing to a point. It has to be fine-tuned in order for life to have a chance.

To explain this absurd bit of luck, the multiverse idea has been growing mainstream in cosmology circles over the past few decades. It got a credibility boost in 1987 when the Nobel Prize-winning physicist Steven Weinberg, now a professor at the University of Texas at Austin, calculated that the cosmological constant of our universe is expected in the multiverse scenario. Of the possible universes capable of supporting life — the only ones that can be observed and contemplated in the first place — ours is among the least fine-tuned. “If the cosmological constant were much larger than the observed value, say by a factor of 10, then we would have no galaxies,” explained Alexander Vilenkin, a cosmologist and multiverse theorist at Tufts University. “It’s hard to imagine how life might exist in such a universe.”

Most particle physicists hoped that a more testable explanation for the cosmological constant problem would be found. None has. Now, physicists say, the unnaturalness of the Higgs makes the unnaturalness of the cosmological constant more significant. Arkani-Hamed thinks the issues may even be related. “We don’t have an understanding of a basic extraordinary fact about our universe,” he said. “It is big and has big things in it.”

The multiverse turned into slightly more than just a hand-waving argument in 2000, when Bousso and Joe Polchinski, a professor of theoretical physics at the University of California at Santa Barbara, found a mechanism that could give rise to a panorama of parallel universes. String theory, a hypothetical “theory of everything” that regards particles as invisibly small vibrating lines, posits that space-time is 10-dimensional. At the human scale, we experience just three dimensions of space and one of time, but string theorists argue that six extra dimensions are tightly knotted at every point in the fabric of our 4-D reality. Bousso and Polchinski calculated that there are around 10,500 different ways for those six dimensions to be knotted (all tying up varying amounts of energy), making an inconceivably vast and diverse array of universes possible. In other words, naturalness is not required. There isn’t a single, inevitable, perfect universe.

“It was definitely an aha-moment for me,” Bousso said. But the paper sparked outrage.

“Particle physicists, especially string theorists, had this dream of predicting uniquely all the constants of nature,” Bousso explained. “Everything would just come out of math and pi and twos. And we came in and said, ‘Look, it’s not going to happen, and there’s a reason it’s not going to happen. We’re thinking about this in totally the wrong way.’ ”

Life in a Multiverse

The Big Bang, in the Bousso-Polchinski multiverse scenario, is a fluctuation. A compact, six-dimensional knot that makes up one stitch in the fabric of reality suddenly shape-shifts, releasing energy that forms a bubble of space and time. The properties of this new universe are determined by chance: the amount of energy unleashed during the fluctuation. The vast majority of universes that burst into being in this way are thick with vacuum energy; they either expand or collapse so quickly that life cannot arise in them. But some atypical universes, in which an improbable cancellation yields a tiny value for the cosmological constant, are much like ours.

In a paper posted last month to the physics preprint website arXiv.org, Bousso and a Berkeley colleague, Lawrence Hall, argue that the Higgs mass makes sense in the multiverse scenario, too. They found that bubble universes that contain enough visible matter (compared to dark matter) to support life most often have supersymmetric particles beyond the energy range of the LHC, and a fine-tuned Higgs boson. Similarly, other physicists showed in 1997 that if the Higgs boson were five times heavier than it is, this would suppress the formation of atoms other than hydrogen, resulting, by yet another means, in a lifeless universe.

Despite these seemingly successful explanations, many physicists worry that there is little to be gained by adopting the multiverse worldview. Parallel universes cannot be tested for; worse, an unnatural universe resists understanding. “Without naturalness, we will lose the motivation to look for new physics,” said Kfir Blum, a physicist at the Institute for Advanced Study. “We know it’s there, but there is no robust argument for why we should find it.” That sentiment is echoed again and again: “I would prefer the universe to be natural,” Randall said.

But theories can grow on physicists. After spending more than a decade acclimating himself to the multiverse, Arkani-Hamed now finds it plausible — and a viable route to understanding the ways of our world. “The wonderful point, as far as I’m concerned, is basically any result at the LHC will steer us with different degrees of force down one of these divergent paths,” he said. “This kind of choice is a very, very big deal.”

Naturalness could pull through. Or it could be a false hope in a strange but comfortable pocket of the multiverse.

As Arkani-Hamed told the audience at Columbia, “stay tuned.”

Reprinted with permission from Simons Science News, an editorially-independent division of SimonsFoundation.org whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the computational, physical and life sciences.

http://www.scientificamerican.com/article.cfm?id=new-physics-complications-lend-support-to-multiverse-hypothesis

Spin Zone: Physicists Get 1st Look at Strange Quantum Magnetism

Jesse Emspak, LiveScience Contributor, 05/26/13

Using super-chilled atoms, physicists have for the first time observed a weird phenomenon called quantum magnetism, which describes the behavior of single atoms as they act like tiny bar magnets.

Quantum magnetism is a bit different from classical magnetism, the kind you see when you stick a magnet to a fridge, because individual atoms have a quality called spin, which is quantized, or in discrete states (usually called up or down). Seeing the behavior of individual atoms has been hard to do, though, because it required cooling atoms to extremely cold temperatures and finding a way to "trap" them.

The new finding, detailed in the May 24 issue of the journal Science, also opens the door to better understanding physical phenomena, such as superconductivity, which seems to be connected to the collective quantum properties of some materials.

[Twisted Physics: 7 Mind-Blowing Findings]

Spin science

The research team at the Swiss Federal Institute of Technology (ETH) in Zurich focused on atoms' spin, because that's what makes magnets magnetic — all the spins of the atoms in a bar magnet are pointed the same way.

To get a clear view of atoms' spin behaviors, the researchers had to cool potassium atoms to near absolute zero. That way, the random thermal "noise" — basically background radiation and heat — didn't spoil the view by jostling the potassium atoms around.

The scientists then created an "optical lattice" — a crisscrossing set of laser beams. The beams interfere with each other and create regions of high and low potential energy. Neutral atoms with no charge will tend to sit in the lattice's "wells," which are regions of low energy.

Once the lattice is built, the atoms will sometimes randomly "tunnel" through the sides of the wells, because the quantum nature of particles allows them to be in multiple places at the same time, or to have varying amounts of energy.

[Quantum Physics: The Coolest Little Particles in Nature]

Another factor that determines where the atoms lie in the optical lattice is their up or down spin. Two atoms can't be in the same well if their spins are the same. That means atoms will have a tendency to tunnel into wells with others that have opposite spins. After a while, a line of atoms should spontaneously organize itself, with the spins in a non-random pattern. This kind of behavior is different from materials in the macroscopic world, whose orientations can have a wide range of in-between values; this behavior is also why most things aren't magnets — the spins of the electrons in the atoms are oriented randomly and cancel each other out.

And that's exactly what the researchers found. The spins of atoms do organize, at least on the scale the experiment examined.

"The question is, what are the magnetic properties of these one-dimensional chains?" said Tilman Esslinger, a professor of physics at ETH whose lab did the experiments. "Do I have materials with these properties? How can these properties be useful?"

Quantum magnetism

This experiment opens up possibilities for increasing the number of atoms in a lattice, and even creating two-dimensional, gridlike arrangements of atoms, and possibly triangular lattices as well.

One debate among experts is whether at larger scales the spontaneous ordering of atoms would happen in the same way. A random pattern would mean that in a block of iron atoms, for instance, one is just as likely to see a spin up or down atom in any direction. The spin states are in what is called a "spin liquid" — a mishmash of states. But it could be that atoms spontaneously arrange themselves at larger scales.

"They've put the foundation on various theoretical matters," said Jong Han, a professor of condensed matter physics theory at the State University of New York at Buffalo, who was not involved in the research. "They don't really establish the long-range order, rather they wanted to establish that they have observed a local magnetic order."

Whether the order the scientists found extends to larger scales is an important question, because magnetism itself arises from the spins of atoms when they all line up. Usually those spins are randomly aligned. But at very low temperatures and small scales, that changes, and such quantum magnets behave differently.

Han noted that such lattices, especially configurations where the potential wells connect to three others, rather than two or four, would be especially interesting. Esslinger's lab showed that atoms tend to jump to potential wells where the spins are opposite; but if the wells are arranged so that the atom can jump to two other atoms, it can't "choose" which well to go to because one of the two atoms will always be in the same spin state.

Esslinger said his lab wants to try building two-dimensional lattices and explore that very question. "What happens to magnetism if I change the geometry? It's no longer clear if spins should be up or down."

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http://news.yahoo.com/spin-zone-physicists-1st-look-strange-quantum-magnetism-131203960.html

Higgs hunters look beyond the Standard Model

Jon Cartwright, 05/06/13

After discovering the Higgs boson last year, researchers at the Large Hadron Collider are now trawling through the data as the collider undergoes an 18-month shutdown for repairs and upgrades. The goal is to discover hints of physics beyond the Standard Model of particle physics – but tantalizing glimpses of new physics have been harder to spot than many physicists had expected.

Three years, eight-quadrillion particle collisions and the discovery of the most infamous particle of them all: the Higgs boson. With such achievements under their belt, you might think that physicists working on the Large Hadron Collider (LHC) at CERN, near Geneva, would be taking a well-earned break. But the current shutdown – a two-year period of repairs and upgrades that began in February – is affording them no holiday. "This is actually the most intense period we've ever had," says Joseph Incandela, spokesperson for the LHC's CMS experiment. "The schedule is so tight there's almost no contingency to prepare for the next run. It's a bit insane."

Since starting up in October 2008 – and following a major malfunction a few weeks afterwards that took a year to fix – the LHC has rarely been out of the headlines. The focus of news has been on the search for the Higgs boson, the last piece in the Standard Model puzzle of elementary particles and forces. Strong hints of the Higgs's existence came last July, when CERN announced the discovery of a new particle, the mass and production rate of which appeared close to Higgs parameters in Standard Model predictions. By March this year, other measured properties, such as zero spin and positive parity, had led the laboratory to claim that the new particle was a Higgs almost without any doubt.

Triumph and disappointment

But while the public has largely taken the discovery of the Higgs boson as mission accomplished for the €3.8bn collider, many particle physicists have been shaking their heads in disappointment. Since it started collecting data, the LHC has exposed few – if any – traces of physics beyond the Standard Model, a framework that is now some 40 years old. There has been no solid evidence for dark matter, supersymmetry, miniature black holes, extra dimensions or any of the other exotic phenomena that theorists excitedly talked about prior to the machine's switch-on. If there is new physics still waiting to be found, the question is: where? And will it turn up in the current shutdown period from an analysis of existing data or in the next, higher energy run?

Those waiting for new physics can take comfort in the fact that the LHC has achieved far more than the discovery of the Higgs over its three-year operation. A year before the Higgs's detection, for instance, the ATLAS experiment found another new boson: the so-called Chi-b(3P) quark-antiquark pair. That was followed by the discovery last year of a new excited Xi(b) baryon by CMS. Although not elementary particles like the Higgs is thought to be, Chi-b(3P) and Xi(b) have helped tie up some of the Standard Model's loose ends by confirming the nature of the strong force, which binds quarks together.

Precision particle physics

Perhaps more important than these particle discoveries, however, have been the LHC's precise measurements of existing Standard Model phenomena. Some of these are quantities that cannot be accurately predicted, such as the high-energy structure of the photon that is being studied by the ALICE experiment. But other measurements can put the latest theories to the test. These include the energy distribution of particle jets (which are produced when quarks collide), and the production rate of pairs of heavyweight elementary particles such as W and Z bosons (which carry the weak force, responsible for radioactive decay) and top quarks. "Those calculations have been taken now to a higher degree of precision," says Incandela. "We have a very good match between our data and our simulations, which tells you that our calculations are very good."

Will the next big news at CERN be about supersymmetry?

Testing the Standard Model in this way is not merely an excuse for self-congratulation; it allows theorists to figure out which of their more speculative hypotheses are worth pursuing. In 2008, for instance, the CDF and D0 experiments at the Tevatron collider at Fermilab in the US accumulated evidence for an unexpected asymmetry in the production of top- and antitop-quark pairs, such that more of the top quarks seemed to fly in the direction of the collider's proton beam than ought to, given Standard Model predictions. Theorists rushed to explain the effect, invoking extra dimensions, supersymmetry and other new physics.

The problem was that the top quark was so heavy – more than 180 times as massive as the proton – that the Tevatron could not generate it in sufficient quantities to give reliable statistics. Conversely, the LHC, which collides protons at record-breaking energies of 7 TeV, has been able to generate millions of top-quark pairs. Although CERN's collider has not been able to shed light directly on the Tevatron's measured asymmetry, it has managed to show, via measurements of a related top-quark asymmetry at ATLAS, that most of those theories proposed to explain it must be wrong (arXiv:1203.4211).

Where are the sparticles?

Besides the discovery of the Higgs, then, one of the main achievements of the LHC to date has been in ruling out new-physics theories, or at least restricting the elbow room, or "parameter space", in which they can operate. Top among all of these theories was always supersymmetry, the idea that every known elementary particle has one or more heavier partners, known as sparticles. Supersymmetry potentially offers a solution to the "hierarchy problem" – why the weak force is 10³² times stronger than gravity – and presents candidates for dark matter, the mysterious substance thought to make up 26.8% of the universe's total mass–energy content. According to particle theorist Ben Allanach at the University of Cambridge in the UK, data taken at the LHC have excluded roughly half of supersymmetry's parameter space.

Much of the data from the LHC's first run has not yet been analysed – the CMS collaboration, for instance, still has to comb through 40% of the 4.7 billion events it recorded last year. Allanach thinks there is a chance that hints of new physics, such as supersymmetry, will crop up in the data analysed during the shutdown period, but he thinks that any big discoveries will have to wait until 2015 when the accelerator restarts at the higher collision energy of 13 TeV. "My hopes are pinned on the next run," he says. "The energy jump now is going to make the big difference. And if supersymmetry is the correct theory of nature, I would be expecting to see a big signal within the first month. If it doesn't crop up, I'll then be getting pretty depressed."

Blind scanning

Others are not so optimistic. Last year, the Latvian theoretical physicist Mikhail Shifman posted an essay on the arXiv preprint server claiming that supersymmetry had failed its basic experimental tests, and that theorists should "stop blindly scanning the parameter space and start thinking and developing new ideas" (arXiv:1211.0004v1). But despite growing pessimism, there may already be signs of supersymmetry in current data. It may even arise out of the recently discovered Higgs boson. Its 125 GeV/c2 mass, combined with its production and decay rate, might fit well with Standard Model predictions, but it might also point to the lightest of several Higgs particles predicted to exist in the simplest versions of supersymmetry.

Bill Murray, deputy physics co-ordinator of the ATLAS collaboration – which, together with CMS, made the Higgs discovery – says that a supersymmetric Higgs would require a supersymmetric partner for the top quark, the "stop", to be found at masses below 1000 GeV/c². "That is a region we're testing enthusiastically," he says. But he stresses that he is open to the possibility of finding no evidence for supersymmetry. "Proving [supersymmetry] wrong would be as important as proving it right," he says. "Null results are hard to sell to newspapers, but they are really important to scientific progress."

A composite Higgs?

Many physicists have latched onto the Higgs discovery, hoping to find out whether it really does fit Standard Model predictions or whether, over the next few years, they will find hints of a more exotic nature. Even if the Higgs is not supersymmetric, there is the possibility that it is not elementary but a composite of smaller particles, or that its existence stretches over higher dimensions.

Theorist John Ellis of King's College London is doubtful whether these more exotic possibilities will be correct, given, he says, that the Higgs's properties are already known to agree with Standard Model predictions to within some 10% on average. But he thinks the next two years of shutdown could offer news on supersymmetry, as the rest of the first run's data is analysed. "Experiments have looked under the most obvious lampposts for supersymmetric signatures," he says. "Now, they've got two years during which all the graduate students can fan out and look under the many other possible lampposts. If we're lucky, something might be lurking underneath one."

About the author

Jon Cartwright is a freelance journalist based in Bristol, UK

http://physicsworld.com/cws/article/news/2013/may/06/higgs-hunters-look-beyond-the-standard-model

Hunting for 'Sparticles': Atom Smasher to Run Through 2012

LiveScience Staff

The world's most powerful atom smasher will continue to run through the end of 2012, with a brief stop for technical reasons at the end of January 2011, officials announced today (Jan. 31).

Meanwhile, scientists smashing protons together at nearly the speed of light announced they are getting closer to narrowing the search for dark matter, that invisible stuff that can be detected only by its tug on normal matter.

The Large Hadron Collider (LHC) is a 17-mile-long (27 kilometer) underground ring run by the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. There, scientists are crashing matter's building blocks together in the hopes of revealing even smaller building blocks - undiscovered particles that make up our universe, including the theoretical "God particle," which is thought to give other particles mass.

And then there's dark matter. The energy released in proton-proton collisions in the LHC manifests itself as particles that fly away in all directions. While most collisions produce known particles, on rare occasions new, exotic ones may be produced, including those known as supersymmetric particles, or "sparticles." The lightest sparticle is a natural candidate for dark matter, researchers say.

To search for these sparticles, an LHC detector looks for collisions that produce two or more high-energy jets, or bunches of particles traveling in approximately the same direction, and significant missing energy.

"We examined some 3 trillion proton-proton collisions and found 13 'SUSY-like' ones, around the number that we expected," said Oliver Buchmueller, of the Imperial College London, but who is based at CERN. "Although no evidence for sparticles was found, this measurement narrows down the area for the search for dark matter significantly."

Buchmueller and colleagues look forward to the 2011 run at LHC, which is expected to bring in data that could confirm supersymmetry as an explanation for dark matter.

"If LHC continues to improve in 2011 as it did in 2010, we've got a very exciting year ahead of us," said Steve Myers, CERN's director for accelerators and technology. "The signs are that we should be able to increase the data collection rate by at least a factor of three over the course of this year."

For instance, in November 2010 scientists began crashing heavy lead ions together in the LHC, dubbing such crashes "little Big Bangs," as they are likely to create conditions closer to the beginning of the universe than ever before (but, of course, on a smaller scale). And later in the month, such super-energetic collisions did create a primordial state of matter akin to what existed at the dawn of the universe.

And, in fact, scientists think 2011 may be the year they find the Higgs boson, or God particle.

The LHC was scheduled to run to the end 2011 before a long break to prepare it for running at its full-design energy of 7 teraelectron volts (TeV). Currently, it's running at half that power - 3.5 TeV.

That's because the cables connecting the superconducting magnets that propel the particles around the LHC ring were built with a flaw that was revealed shortly after the machine was first turned on. In order to ramp up the power, LHC workers will have to shut down the accelerator and make significant repairs to the magnet connectors.

Once that's done, and LHC is running at peak design parameters, particles will be colliding at a mind-blowing 600 million events per second. For comparison, about 6 million particles currently collide per second.

The schedule announced today foresees beams back in the LHC next month and running through to mid-December, then a short technical stop over the year before resuming in early 2012.

You can follow LiveScience Managing Editor Jeanna Bryner on Twitter @jeannabryner.

http://news.yahoo.com/s/livescience/20110201/sc_livescience/huntingforsparticlesatomsmashertorunthrough2012

Scientists collide lead ions in Big Bang machine

Frank Jordans, Associated Press

GENEVA – Scientists at the world's largest atom smasher said Monday they have succeeded in recreating conditions shortly after the Big Bang by switching the particles they use for collisions from protons to much heavier lead ions.

The Large Hadron Collider recorded its first lead ion collisions on Sunday and has since stabilized the twin beams sufficiently to start running physics experiments, said a spokeswoman for the European Organization for Nuclear Research, or CERN.

The collisions produce an effect that is as close as researchers have ever come to observing the state of matter moments after the formation of the universe, which is believed to have begun with a colossal explosion known as the Big Bang.

The event inside the collider "is a very, very, very small bang," CERN spokeswoman Barbara Warmbein told The Associated Press.

Still, researchers are hoping the collisions will be powerful enough to produce a thick soup of matter called "quark-gluon plasma" that will help them gain a deeper insight into how the universe began.

The $10-billion Large Hadron Collider was fired up in September 2008 and, despite some technical setbacks, has been hailed by scientists as a key tool for understanding or reshaping our knowledge about the universe.

Most of the time it will be used to smash together protons in the hope that one of the four giant detectors - situated around the collider's 17-mile (27-kilometer) tunnel under the Swiss-French border - will find evidence of dark matter, antimatter and maybe even hidden dimensions of space and time.

But for one month each year, before shutting down for winter maintenance in December, the Large Hadron Collider will smash together lead ions, said Warmbein.

Lead ions - which are lead atoms with the electrons removed - are much heavier than protons, meaning the energy used to circulate them is far higher.

"They are more likely to create the state of matter that ALICE is looking for," said Warmbein, referring to the detector that will be used to search for the plasma.

The resulting quark-gluon plasma, which is initially many times hotter than the sun, quickly cools, causing subatomic particles to stick together and form protons and neutrons. Scientists believe that by studying this process they will better understand how matter came into being.

Warmbein said that it will likely be months, if not years, before scientists make significant new discoveries.

http://news.yahoo.com/s/ap/20101109/ap_on_sc/eu_switzerland_big_bang_machine

CERN scientists eye parallel universe breakthrough

Robert Evans

GENEVA (Reuters) – Physicists probing the origins of the cosmos hope that next year they will turn up the first proofs of the existence of concepts long dear to science-fiction writers such as hidden worlds and extra dimensions.

And as their Large Hadron Collider (LHC) at CERN near Geneva moves into high gear, they are talking increasingly of the "New Physics" on the horizon that could totally change current views of the universe and how it works.

"Parallel universes, unknown forms of matter, extra dimensions... These are not the stuff of cheap science fiction but very concrete physics theories that scientists are trying to confirm with the LHC and other experiments."

This was how the "ideas" men and women in the international research center's Theory Group, which mulls over what could be out there beyond the reach of any telescope, put it in CERN's staff-targeted Bulletin this month.

As particles are collided in the vast underground LHC complex at increasingly high energies, what the Bulletin article referred to informally as the "universe's extra bits" -- if they do exist as predicted -- should be brought into computerized, if ephemeral, view, the theorists say.

Optimism among the hundreds of scientists working at CERN -- in the foothills of the Jura mountains along the border of France and Switzerland -- has grown as the initially troubled $10 billion experiment hit its targets this year.

PROTON COLLISIONS

By mid-October, Director-General Rolf Heuer told staff last weekend, protons were being collided along the 27-km (16.8 mile) subterranean ring at the rate of 5 million a second -- two weeks earlier than the target date for that total.

By next year, collisions will be occurring -- if all continues to go well -- at a rate producing what physicists call one "inverse femtobarn," best described as a colossal amount, of information for analysts to ponder.

The head-on collisions, at all but the speed of light, recreate what happened a tiny fraction of a second after the primeval "Big Bang" 13.7 billion years ago which brought the known universe and everything in it into being.

Despite centuries of increasingly sophisticated observation from planet Earth, only 4 per cent of that universe is known -- because the rest is made up of what have been called, because they are invisible, dark matter and dark energy.

Billions of particles flying off from each LHC collision are tracked at four CERN detectors -- and then in collaborating laboratories around the globe -- to establish when and how they come together and what shapes they take.

The CERN theoreticians say this could give clear signs of dimensions beyond length, breadth, depth and time because at such high energy particles could be tracked disappearing -- presumably into them -- and then back into the classical four.

Parallel universes could also be hidden within these dimensions, the thinking goes, but only in a so-called gravitational variety in which light cannot be propagated -- a fact which would make it nearly impossible to explore them.

(Editing by Jonathan Lynn)

http://news.yahoo.com/s/nm/20101020/sc_nm/us_science_cern