A ‘New Physics’? Scientists May Have Glimpsed a World Beyond the Standard Model


Physicists are using the LHC to probe for elementary particles that may exist beyond the Standard Model. By doing so, they may discover (and may have already discovered) a “new physics” that has a real chance to resolve some of the greatest mysteries in science.
MESON, FERMIONS, LEPTONS, AND BOSONS

The Standard Model, which emerged in the 1970s, is a theoretical foundation that explains the world and matter at the very smallest levels of reality: elementary particles so minute they boggle the imagination and defy easy understanding.  It has been a pretty successful description so far, but like most old foundations, it’s beginning to show signs of cracks and disrepair.

Of course, it’s not so much that the standard model is wrong; rather, there may be a deeper kind of physics, a dark sector that we haven’t been able to reach yet.

In other words, there are hints of something greater and even more fundamental shining through those cracks like glinting rays of sunshine.  And a team of physicists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN), working with the LHC particle accelerator at CERN, think they may be on the track of what that “something” is.

Briefly, the Standard Model divides matter and the forces of the universe into several categories of elementary particles.  Pay attention now, reader, because this will go quickly.  Bosons transmit force; photons (light) emerge from electromagnetic activity; eight species of gluon are involved in the strong nuclear force (holding atoms together); and the W+, W- and Z0 bosons oversee the weak nuclear force (responsible for radioactive decay).  Matter comprises fermions, which are formed by quarks and leptons; there are six species of quarks, and six of leptons (which include electrons and neutrinos), together with 12 antiparticles for each.  The Higgs boson provides mass for all, save the gluons and photons.

Got that?  Good.

But here’s the problem—the Standard Model, in common with other theories explaining the universe (such as Quantum Mechanics and General Relativity), is not quite as comprehensive as we’d like it to be.  It fails to explain some of the most interesting and pressing questions confronting physics.

For instance, it doesn’t account for the division of fermions into different families, or why matter achieved the upper hand over antimatter in the early universe.  And if dark matter is indeed an actual form of “matter,” it is not explained by our current understanding of elementary particles.  Perhaps most importantly, gravity (that most mysterious and fundamental of forces) is utterly unaccounted for by the Standard Model.

Highly complicated, graphical analysis of the decay of a "beauty" meson into a kaon and two muons. Credit: CERN
Highly complicated, graphical analysis of the decay of a “beauty” meson into a kaon and two muons. 
THE BEAUTY MESON

The Large Hadron Collider has turned its considerable particle-smashing heft to the task of seeking out new elementary particles beyond the Standard Model; but it’s possible they exist just outside the energy limit of the LHC.  If this is the case, then the only way to discover their presence will be to discern their “shadow,” as it were—the influence they exert upon other particles at lower energies.

And one way this might work is if they cause “mesons”—unstable, short-lived combinations of a quark and antiquark—to decay in unusual and unexpected ways.

This is what the team believes it may have found. A few years back, the LHCb experiment, which probes the mysteries of matter and antimatter, detected anomalous readings in the decay of a B meson or “beauty” meson—a meson consisting of a light quark and a heavy beauty antiquark.  It was necessary to rig up a more accurate method of determining the parameters by which the beauty quark decayed in order to test its deviation from the Standard Model; the Polish team devised a means to determine the parameters independently.

According to Dr. Marcin Chrzaszcz of IFJ PAN, one of the authors of the new research, “[m]y approach can be likened to determining the year when a family portrait was taken. Rather than looking at the whole picture, it is better to analyze each person individually and from that perspective try to work out the year the portrait was taken.”

By more accurately determining the degree of deviation from the Standard Model, scientists will be able to ascertain whether the anomaly really represents the influence of unknown elementary particles beyond the Model, or whether it is merely some hitherto undiscovered property which the Model does account for.

For now, physicists hypothesize that there is something called a “Z-prime” (Z’) boson, which mediates the decay of B mesons.  The LHC is gearing up now for new, higher-energy collisions. Perhaps, at last, they’ll discover the new particles, and the new physics, they’ve been searching for.

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Breakthrough ‘Madala Boson’ Could Unlock the Mysteries of Dark Matter


The Higgs’ boson helped us understand known matter, but scientists at the High Energy Physics Group (HEP) of the University of the Witwatersrand in Johannesburg believe they have the necessary data to discover a new boson, called the Madala boson. Its discovery may help us explore more about what dark matter is and how it interacts with the universe.

DISCOVERING THE MADALA BOSON

Discovery of the Higgs boson in 2012 at the European Organization for Nuclear Research (CERN) has contributed heaps to our understanding of modern physics. But the Higgs boson only explains mass that we can see, touch and smell. Known matter only makes up 4% of the Universe’s mass and energy. Scientists predict the discovery of a new boson which interacts with dark matter, which makes up 27% of our universe.

Using the same data that led to Higgs’ discovery, the bright minds at the High Energy Physics Group (HEP) of the University of the Witwatersrand in Johannesburg have come up with the Madala hypothesis, which they believe will help them discover the new Madala boson.

The Madala boson team isn’t lacking in scientific minds, as they have around 35 students and researchers to brainstorm and help understand data from the experiments. They also have the support from Wits University, such as theorists Prof. Alan Cornell and Dr. Mukesh Kumar and Prof. Elias Sideras-Haddad’s assistance in detector instrumentation.

Image credit: Taylor L; McCauley T/CERN
Image credit: Taylor L; McCauley T/CERN

DARK MATTER MATTERS

Man’s understanding of physics keeps on evolving. Professor Bruce Mellado, team leader of the HEP group at Wits says we are now at a point similar to when Einstein formulated relativity and to when quantum mechanics came to light. We found classic physics lacking as it failed to make sense of plenty of phenomena. When the Higgs’ boson was discovered, the Standard Model of Physics was completed, but we have still only scratched the surface. Modern physics still can’t explain other phenomena including dark matter.

The discovery of the new Madala boson puts man in a good position to learn more about our universe. Perhaps there are even more particles to be discovered aside from this new boson. The future of modern physics has never been brighter.

The Search for New Physics at CERN



Anomalous collision events observed in Run 2 of CERN’s Large Hadron Collider in 2015 may point to new physics beyond the Standard Model. Image courtesy of CERN.

 

In February, I spent a few days at CERN, the European Organization for Nuclear Research. I spoke with physicists who devote themselves to understanding the stuff the universe is made of. These were the people who collaborated with thousands of other physicists to find the Higgs boson. Now they are looking for physics that lies beyond theStandard Model—the theory of nature that has dominated the field for more than forty years.

Some of our conversations focused on a puzzling anomaly that was announced at CERN in December 2015. The physicists I spoke with were calm, perplexed, and excited. Calm, because they thought the anomaly might well disappear as evidence accumulates over the coming months. Perplexed, because they did not know what to make of what they had observed. Excited, because they hoped they would find something new and strange that would upset their understanding of nature.

It was depressing to come back to the current political season, with its breathtaking blend of authoritarian bluster, racist garbage, and sheer bullshit. True, politics is not particle physics. Physicists do not declare a discovery until they think the chance of a mistake isless than one in three million. In politics, we do not have that luxury: we need to act. Still, we have a lot to learn from the fallibilist humility that defines fundamental physics: you make your ideas clear, acknowledge your ignorance, and hope for a surprising refutation of settled expectations.

With this piece, Matt Buckley, a theoretical physicist and professor at Rutgers University, begins a series of eight articles that will lead us into these waters. The series starts from the anomaly announced in December and will end with another announcement from CERN in summer 2016, which will tell us whether the anomaly is nature’s signal or just statistical noise. Buckley will lay the foundations for understanding the current calm and perplexed excitement. He will give us a feel for the physics and a sense of how physicists think and work. Politics may not be particle physics, but we have much to learn from this remarkable practice of submitting our beliefs to the discipline of evidence and argument. Physicists will ask questions; nature will talk back; and we will get to watch it unfold in real time.

— Joshua Cohen, co-editor


 

December 15, 2015, was a very big day at CERN. Certainly it was the biggest since July 4, 2012, when scientists announced that they had found the Higgs boson. This discovery—like the recent discovery of gravitational waves from the merger of black holes more than a billion years ago—was one of the most important scientific events of the last forty years. Named for Peter Higgs, the Scottish physicist who predicted it in 1964, the particle was the final missing piece in the Standard Model, physicists’ fundamental theory of visible matter. Though physicists at CERN were pretty confident that they would find the Higgs, actually finding it was a remarkable achievement: a stunning feat of science, engineering, and human collaboration. The particle was produced by colliding protons at enormous energies in CERN’s Large Hadron Collider (LHC). (Protons are one type of hadron, a special type of subatomic particle.) After it was produced, the Higgs was identified by two big detectors,ATLAS (A Toroidal Large Hadron Collider Apparatus) and CMS (Compact Muon Solenoid).

Following the Higgs announcement, CERN was shut down for upgrades for more than two years. It was fired up again in early 2015, and on December 15, ATLAS and CMS announcedthe initial findings from this new run. The results were the first taste of the physics of energy scales vastly higher than anything we have ever seen—nearly twice as high as the energies that yielded the Higgs. Buried deep in the talks in December, among the outcomes of many other results from ATLAS and CMS, were a couple of innocuous slides with a few tentative suggestions of something we call “new physics.” Nothing solid, nothing that could rise to level of discovery, but their mere existence had sparked rumors for weeks before the official announcements.

These hints were enough to set wheels in motion. Immediately after the December presentation, all around the world, a thousand physicists ran out of their offices to find someone to start arguing with about the results. Within a day, the first papers hit the arXiv, a public repository of physics and mathematics research, where papers can be posted for comment before peer review. By the end of the month at least 150 papers had appeared. The questions on everyone’s mind then are still on everyone’s mind now. What did the results mean? Are we seeing experimental error? Or random noise, like a blast of static on the radio? Or was this the first sign of physics beyond the Standard Model?

The Standard Model has been the consensus theory in physics for roughly forty years. It tells us that the visible world is made of a small set of fundamental particles, and it tells us how those particles work and interact. If the hints in the CMS and ATLAS data are vindicated—and that’s a big “if”—then particle physics would enter a new era. Our fundamental theory of the natural world would need to change, and no one knows quite how. This chance, however slight, has driven the extraordinary response among physicists to the announcement of the ATLAS and CMS results. Everyone wants to be part of what would be the biggest news in our field—perhaps the biggest scientific news—in nearly a half century.

So what is this Standard Model? What exactly are these experiments? And what did they see that got so many physicists so worked up?

I will explore these questions in a series of articles. CERN scientists will clarify the findings over the next several months and announce new results this summer. As the research proceeds, I will set the stage for the announcement. The idea is to provide you with a basic understanding of the results when they come in—and a sense of why we are all so excited.

• • •

The puzzling new data were gathered at the LHC, a twenty-seven kilometer ring more than a hundred meters underground that curves from CERN headquarters in Geneva, Switzerland, and into France before completing its circuit. When the LHC is in full swing, two beams of protons speed around the ring at 99.9999991 percent of the speed of light. They are kept on their curved path by titanic magnetic fields generated by nearly 10,000 superconducting magnets.

The two beams circulate in opposite directions, just over seven inches apart. But at four points along their underground course, the beams are bent just a bit more and made to cross. The protons come in bunches, roughly 100 billion in each bunch. When the beams cross, which happens 40 million times every second, virtually all of the protons miss their counterparts on the opposite beam and continue back onto the ring to complete another circuit in 0.0009 seconds. But a precious few—maybe fifteen or twenty pairs—collide.

Was this the first sign of physics beyond the Standard Model?

If two cars collide head-on, their kinetic energy—their energy of motion—has to go somewhere: to sound waves, to compression of structures in the frame, to propelling pieces of the cars long distances at high speeds. The same is true for the LHC’s protons, except, proportionally, they carry vastly more energy than cars on a highway. In the LHC’s first run (2010–2012), each proton carried enough kinetic energy to make—in principle—over 4000 new protons. (Remember Einstein’s famous equation E = mc2, which means that energy and mass are interconvertible, and that the speed of light squared is the rate of conversion.) In the LHC’s second run in 2015, this value had been increased; each proton carried more than 6500 times the energy needed to make a single proton. (In the units used by particle physicists, a proton “weighs” a bit less than a gigaelectronvolt, abbreviated GeV. The LHC beams now consist of protons with 6500 GeV of energy.) This extra burst of energy, made possible by even stronger superconducting magnets, is what makes this new run of the LHC so exciting.

To understand what happens when protons collide, bear in mind that even though protons are really small, they are not elementary particles—the most fundamental particles in nature. Rather, protons are made of a roiling ocean of particles called quarks and their antimatter counterparts called antiquarks (always with three more quarks than antiquarks), held together by still more particles called gluons. Often a collision of protons just results in a rearrangement of those constituents: the huge kinetic energy is redirected to throw quarks, antiquarks, and gluons off in random directions, much like pieces of a car flying off in a head-on wreck or the insides of a watch when it is smashed against a wall.

Sometimes, however, the kinetic energy from the collisions is channeled into the production of completely new particles. These new particles aren’t constituents of protons, but they can be summoned into existence—for a very, very short time—by the colossal amount of energy available when protons collide. In a later article, I’ll explain in more detail about how to picture this process of producing fast-fading particles. For now, just know that this is why we built the LHC: to give us a chance to see what new stuff comes out when you focus enough energy into a tiny region.

• • •

One thing that can (and did) come out of these collisions is the Higgs boson. Officially, the LHC’s principal aim was to produce and detect the Higgs. Its discovery significantly advanced our understanding of the Standard Model.

Yet although the Standard Model is the most precise and accurate theory ever devised in science, from nearly the moment of its discovery it was known to be incomplete: a hitherto unseen particle with very unique properties had to exist. Otherwise the whole theory of visible matter falls apart. Searching for the Higgs was made harder by the fact that the Standard Model does not predict its mass, so we did not know exactly where to look. Since the 1970s we’ve been searching, in one way or another, for the Higgs: experiments such as the Large Electron Positron collider (at CERN) and the Tevatron (at Fermilab, thirty miles west of Chicago) did not find it. (It turns out that they lacked the ability to pump enough energy into the collisions to create the Higgs in large numbers, though we had no way of knowing that at the time.) The Superconducting Supercollider, planned to be constructed in Texas, would have reached energies vastly greater than the LHC in the late 1990s. But in 1993, after half the ring was built and much political conflict, the project was cancelled. The LHC was the machine that was going to find the Higgs: there were “no-lose” theorems to prove that it could be done, and find it the LHC did.

Of course, throwing two protons together at vast energies is only half the battle. It isn’t enough to create the Higgs; you also have to detect it, which is hard because the particle lasts only for 0.0000000000000000000001 seconds before decaying into other particles. The only way to find it is indirect: by detecting the less massive particles that it decays into. To do this, at each point where the proton beams cross, massive detectors were constructed. ATLAS and CMS are two of them; think of them as very big and very complicated cameras. (ATLAS is 45 meters long, 25 meters in diameter, weighs 7000 tons, and has 10 million components.) These two detectors have very different designs and are run by separate teams of physicists, some 3000 for CMS and 5000 for ATLAS. This redundancy serves as a quality control check: each experiment gathers its own data, analyzes it independently, and each team has a burning desire to beat their counterparts to the punch.

ATLAS and CMS are designed to detect and measure the properties of as many different particles coming out of a proton-proton collision as possible, and to decide whether the collision meets some minimal, if vague, standard of “likely to contain interesting physics.” Most collisions do not pass that test, but for the few that do, the detector relays the information to the outside world, where it is saved for later analysis.

This whole effort is a massive engineering and physics challenge: particles do not come with handy ID cards telling you what they are and where they’re going. Instead, the ATLAS and CMS experiments must track how energy appears to be deposited in various materials that make up their detectors (starting with lots of silicon pixels close to the collision point), and then carefully unravel this pattern to determine what particles went where. The combination of the LHC and its four experiments (ATLAS, CMS, and two more specialized detectors, ALICE and LHCb) are among the most complicated artifacts ever constructed by humanity, and it is all custom-made, designed and constructed by thousands of physicists in labs around the world.

Once the information about what happened in a collision—the “event,” as it is called—has been safely stored “on tape” (a terminological throwback to the days when data-storage was on magnetic tape, rather than solid-state hard drives), the analysis can begin. Though the Higgs boson was the principal reason for the LHC’s construction, it was never the only target. The Standard Model is known to have problems that cry out for solutions. For various reasons, which I will explore in later articles, we suspect that some of these will be solved by physics that becomes manifest at energies not too far above the mass of the Higgs boson itself. There is no no-lose theorem here, however, and the possibilities for what could be lurking at high energies are not quite endless, but certainly immense.

Thus, the experimental physicists working on ATLAS and CMS look for as many things as they can think of. Part of the job of a theoretical physicist is to think up more things to look for, all for the sake of figuring out what the world is ultimately made of and how those ultimate constituents work. One great fear is that there is something new at the LHC and we’re just not clever enough to figure out where to look for it. The other great fear is that there is nothing new to be found. All we can do is cast as wide a net as we can, and be diligent.

• • •

The method of looking for new physics that sparked all the rumors prior to December 15 were the “diphoton” searches done separately by ATLAS and CMS experimentalists. These are very simple searches, as far as these things go. They require none of the baroque tricks that theorists like myself had spent many years developing (though of course they still require the dedicated work of many trained scientists to complete).

Every event at the LHC contains photons (particles of light), thousands of them in fact, with about the energy of the photons coming from an X-ray machine. The experimentalists were interested not in those everyday photons but the ones that contain tens or hundreds of billions times more energy. And not just any photons: pairs of photons (diphotons) that show up at the same time in a layer of the detector that is very good at photon detection. The hope was that these diphotons would be the signal of something new. But, as with many types of particles at the LHC, pairs of extremely energetic photons can be made in lots of different ways, including interactions from the physics of the Standard Model as well as interactions that could arise from a new particle. So seeing a bunch of diphoton events isn’t necessarily interesting; the experimentalists needed some way to distinguish diphotons that might have come from new physics and those that originated in well-understood physics. In particular, they needed a way to pick out pairs of photons that come from some new particle that was produced in a collision of LHC protons and then promptly fell apart (“decayed”), emitting two particles of light.

One fear is that there’s something new to be discovered and we’re just not clever enough to find it.

To do this, they relied on a useful property of particles—useful, but a little complicated. One of the things that defines a particle is its mass, and one of the properties of mass is that no matter how you are moving relative to a particle, or how the particle is moving relative to you, you will always measure the mass to be the same value. (In other words, mass is what physicists call a “relativistic invariant.”) A proton always has a mass equivalent to a bit less than 1 GeV in energy, for example. A massless photon is always seen as having zero mass.

Suppose now that you create a new particle in a collision between protons, and suppose that the new particle decays eventually into two photons. Those two photons inherit some information about their parent. While an individual photon is massless, you can take two photons and combine their energy and momentum to construct something called the “invariant mass” of the pair. This invariant mass, denoted mγγ (pronounced “m-gamma-gamma”), is the same as the mass of the parent particle. So if you can make many such new particles and capture the light from their decay in the detector, you will see many pairs of photons, all with the same invariant mass. For example, if you make some Higgs particles, and they decay eventually into photon pairs, the invariant mass of all the pairs will be the same as the mass of the Higgs.

For pairs of photons that are just produced from some random smashing of a proton against another proton, this quantity, the invariant mass of the two photons, will not always be exactly the same, as the photons can be produced in all sorts of ways, not just from the decay of a single type of particle with a unique mass. In general, in such collisions mγγ will be smoothly distributed, roughly tracking how much energy went in to making the pair of photons; the bigger the invariant mass of the photon pair, the less often we will see it.

So when you create a new particle (say, a Higgs) that sometimes decays to create diphoton events, you will see an elevated number of those events, all with the same invariant mass. If you plot the number of events with a given invariant mass, this results in a “bump,” which will stick out like a sore thumb over the “background” of diphotons created in other ways. For this reason, such searches at the LHC are called “bump-hunts.”

Here is an example. The Higgs is one particle that can decay into a pair of photons; one of the ways that the Higgs was discovered was through exactly this sort of bump-hunt. The Higgs has a mass equivalent to 125 GeV of energy. (Particle physicists use the same unit for mass and energy, again because of E = mc2.) So, when ATLAS and CMS collected events, they started to see an excess of diphoton events around an mγγ of 125 GeV. Of course, they didn’t know ahead of time that the Higgs mass was 125 GeV: they learned it only by seeing this bump and working their way back from there.

You can see the progression of the Higgs search in a handy gif the ATLAS experiment created afterwards. In the animation, the number of diphoton events collected is increasing as time goes by. The horizontal axis is the invariant mass mγγ of the diphotons measured by ATLAS, and the vertical axis is the number of events with diphotons that have a particular invariant mass.

Animation showing ATLAS evidence for the Higgs boson during Run 1 of the LHC. Image courtesy of ATLAS/CERN.

In this animation, there is a nice smoothly falling “background” of diphoton events. These are coming from well-known Standard Model processes. Then, at an invariant mass of 125 GeV, you start seeing a visible excess creep out over the background, once enough data has been collected. That’s the Higgs, as it was discovered at ATLAS: it was created in collisions of protons and then decayed into a pair of photons, which remembered enough of their parent to show up on this plot as a bump at a particular invariant mass.

• • •

As the Higgs discovery demonstrates, diphotons can be used to discover new physics. But it isn’t the only way to do so, of course. There are literally hundreds of possible ways to look for something new at the LHC. But diphotons are a “clean” way to look: the particles in the collision are relatively straightforward for the experimentalists to see in their detectors (they show up as pairs in what is called the “electromagnetic calorimeter”). They are also relatively straightforward to analyze; the invariant mass gives a simple way to see new physics jump out at you from the data. All this sort of search needs, then, is a new particle that can decay into a pair of photons.

This finally brings us back to the results of the ATLAS and CMS searches announced on December 15. Here is the ATLAS data:

Diphoton ATLAS data from Run 2 of the LHC. Image courtesy of ATLAS/CERN.

And here is the CMS data:

Diphoton CMS data from Run 2 of the LHC. Image courtesy of CMS/CERN.

These plots, like the Higgs plots above, show the number of events with diphotons that have a particular invariant mass. The difference is that these new plots come from the second run of the LHC, which collides protons at higher energies. That means the experimentalists can hope to make more massive new particles and can look at higher invariant masses of diphoton pairs than they could before.

There are a bunch of things going on with these plots, so let me draw your eye to particular features. First, in both cases, the experimentalists have drawn a background line (red for ATLAS, blue for CMS). This is their best estimate for the number of events that they should see at a given invariant mass, according to the Standard Model. Notice that the actual number of events at any given invariant mass doesn’t always match the prediction. Such departures are especially pronounced at the far right side of the plots, where the invariant mass is largest. Here, the number of predicted diphoton pairs is very small, less than one per range of invariant mass. Since you can’t actually see a fraction of an event—it either happened or it didn’t—the predicted and observed numbers of events are expected to deviate, and the way experimentalists compare what they expected to see and what they actually saw takes these small number of events into account.

Away from the right-side tail, however, the background prediction and actual number of events are in pretty good agreement, though they are not exactly the same. That’s as it should be. A background estimate is exactly that: an estimate. If you flip a coin a hundred times, you expect it to come up heads about fifty times. But you’re not going to be very surprised if, after a hundred flips, you have sixty heads. That’s not quite the expectation, but some percentage of the time you’re going to get fluctuations away from that value. As long as those fluctuations aren’t too far away from your expectation, you’re not too bothered. Of course, if you flip a coin a hundred times and see ninety-four heads, you might start to suspect that your coin isn’t a fair coin. Critically, though, you couldn’t say for certain that the coin is biased, no matter how frequently and extremely it departs from the average value you expect. All you can say for sure is that it’s extremely unlikely that the coin is fair (and you could put a specific number on how unlikely it is).

The background lines in the CERN plots are like the expectation of seeing fifty heads in a hundred flips of a coin. Deviations around that expected value are consistent with the Standard Model, as long as those deviations are small compared to the number of diphotons collected. But if you see a large fluctuation away from that expectation, you have some reason to believe that there’s something else going on (new physics, or a biased coin in the analogy). I’m simplifying a little, of course, since the background expectation for ATLAS and CMS have to be determined using the data itself. This is unlike the fair coin example, where the background expectation is something you can figure out ahead of time.

As you read the ATLAS plot from left to right (increasing invariant mass along the horizontal axis), you see the actual number of events detected (the black crosses). They more or less track the background expectation, though there are some small deviations both up and down. But then, at an invariant mass of 750 GeV, there is a rather large bump: there are about twenty photons around this invariant mass. Now twenty is not a lot in absolute terms, but the Standard Model tells us that the number should be closer to eight. So we have a huge upward fluctuation from the background. That can happen simply due to random chance, just as it can happen that you can flip a fair coin a hundred times and get seventy-five heads. But if that happened with a coin, you would start looking at it pretty closely, wondering if something was going on.

We can put a number on how unlikely it is. Remember that the Higgs was found through a diphoton bump. How likely was it that the bump was due to chance? Not very likely: 1 in 3,488,560.

Similar calculations show that the ATLAS bump at 750 GeV could occur by chance only once in 6285 tries. That sounds pretty convincing. But recall that we had no special reason for looking at 750 GeV. We would have been equally happy with a big fluctuation at any invariant mass: 740, 730, 720, and so on. In effect, we “tried” many times to see a fluctuation, and we have to take that promiscuity into account. This is called the “look-elsewhere” effect.

Think of the look-elsewhere effect using the following analogy. You have a 1 in 365.25 chance of sharing the same birthday as any random individual. Imagine that you meet exactly one person, and you ask what their birthday is, and it is the same as yours! You’d be right to be very surprised. However, imagine that you run into a hundred people, and you ask all of them what their birthday is. Suddenly, the chance that someone shares a birthday with you is about 25 percent. You’ve looked in a lot of places, and so getting one result that’s somewhat rare becomes a lot more likely. Seek and ye shall find—or have a pretty good chance of finding, anyway.

Applying this “look-elsewhere” reasoning to the ATLAS search drops the odds of the bump being the result of random fluctuation from 1 in 6285 to around 1 in 44. That’s really not very low: in physics such numbers are routinely filed under “maybe interesting, but wait and see.” ATLAS does hundreds of searches, so about 1 in 22 will have a fluctuation of that order of magnitude in their results. We’re used to that.

But now look at the CMS plot. Instead of scanning your eye from left to right along increasing invariant mass, jump straight to 750 GeV. ATLAS already told you to look there, after all. And what’s that? At 750 GeV in the CMS data, you find a few more events than there “should” be, according to the Standard Model. Maybe ten events, while you were expecting four.

By itself, this result should happen due to random chance about 1 in 214 tries. If CMS were the only experiment to report such results, you’d have to apply the look-elsewhere effect again, and the significance of this result would drop precipitously. But ATLAS already told us this particular region was interesting; we no longer need to look elsewhere. And since the CMS and ATLAS experiments are completely separate from one another, we’ve basically tried twice to test the physics at this particular invariant mass, and in both cases we’ve come up with something that is really unlikely.

That is what makes this result so interesting: seeing something unusual not once, but twice, in results from groups that have different experiments, different ways of collecting data, and different ways of analyzing their data, and that don’t share their results with each other ahead of time. To some degree, one experiment provides an independent validation of the other.

But even this convergence of independent evidence is not definitive. This kind of coincidence has happened before even though the results turned out to be insignificant upon closer inspection. Two experiments can see unusual results in the same spot, and then, when more data comes in, everything can revert back to the expectation. After all, the LHC experiments look for new physics in a lot of places, so unlikely things can happen. Therefore, the safest bet, based on past experience, is that these results will also disappear once we get more data from another LHC run. Perhaps we just stopped the LHC collisions at a time when both experiments had a few more diphotons than normal. Physicists who say this have an annoying track record of being correct.

The flip side is that this particular result—as far as I can tell—is the most surprising result to come out of the LHC other than the discovery of the Higgs itself. In short, the CMS and ATLAS results combined are the mostly unlikely things to have been seen if the Standard Model is the only physics around, other than the one time we discovered a new particle.

That’s enough to get a lot of people sitting up and paying very close attention.

• • •

If the CMS and ATLAS hints pan out, we’ll have discovered something completely and utterly new. That hasn’t happened in a very long time in collider physics.

In fact, we can go even further. Based on this first round of data—and you have to keep in mind that the results are very preliminary—we can say that if these diphoton bumps are real, they are the sign not only of new physics, but of new physics of a kind we were absolutely not expecting. We know they would point beyond the Standard Model, but we do not know the direction they would point us in.

If the elegant idea can’t explain the data, so much for the elegant idea.

In the years leading up to the construction of the LHC and then the discovery of the Higgs, theoretical physicists had plenty of time to think about what should be lurking above the energies we had tested with other colliders. There were, of course, many ideas. But several gained popular currency thanks to the “elegant” ways they solved the problems we were wrestling with. (Mathematicians and physicists speak often of searching for “elegant” theories. The mathematician G.H. Hardy went so far as to say “there is no permanent place in the world for ugly mathematics.”) These theories tend to predict lots of different particles, with many different signals that would appear at the LHC, given the energies that are now being attained. Simple versions of these theoretical ideas have become benchmarks against which we test the ability of the LHC to find new physics. Interestingly, even though these benchmark theories were chosen specifically because they could result in so many interesting signatures at the LHC, they do not predict the signal we’re seeing in the ATLAS and CMS diphotons. The excess at 750 GeV is a little too weird to be explainable by these elegant ideas we’ve spend several decades honing.

That is why it is such tremendous fun to try to explain these new results. Without new physics, we theorists had to rely on aesthetic criteria—a certain degree of elegance, an economy of design—to guide our intuition about the “right” idea to pursue. But the universe never promised us a rose garden. If the elegant idea can’t explain the data, so much for theoretical aesthetics. The demand for beauty goes out the window in the face of experimental hints, and you’re free to consider ideas that are ugly but get the job done (though everyone will have their own personal measure of what counts as too ugly to consider pursuing). So there’s a flurry of activity, and optimistically, someone will stumble on the right idea, which might turn out of have aesthetic appeal all of its own.

In the end, we can only say one thing for sure: we need more data.

From a personal perspective, it is incredibly frustrating not to know what to make of these new results. The time physicists spend working on this is time we are not working on other ideas, ideas that we can be sure will continue to be important even after the LHC turns back on in a few months. To spend your time pondering something which could be flat out untrue is scary from a career perspective and dispiriting from the perspective of wanting to know how the universe works. To be not just wrong (which is part of the job), but irrelevantly wrong, wrong in a way that teaches you nothing? That’s not what any of us want.

On the other hand, this work is deeply exciting. It is what science is all about—at least the part of science that most scientists dream of (the remaining bits being some mixture of hard work, coffee, grant writing, more coffee, conferences, and gently banging your head against a wall).

For someone like me, in my mid-thirties in particle physics, this is brand new: we’ve never had a truly unbelievable surprise. It was great to find the Higgs boson, but it fit perfectly into the received theories, ideas that I studied in graduate school. We don’t know whether this diphoton excess is the first step into the undiscovered country beyond the Standard Model. But ATLAS and CMS are breaking new ground, reaching energies that have never before been probed by humanity.

In this series, I will try to guide you through this exciting work. By the time I get to the end, I hope to be able to tell you what is going on with those photons we saw at the LHC. The safe bet is that I will have to report that this result, like many others, is not interesting. But maybe not. I don’t know, and neither do you; that’s the beauty of it.

CERN scientists ‘break the speed of light’


Scientists said on Thursday they recorded particles travelling faster than light – a finding that could overturn one of Einstein’s fundamental laws of the universe.

 Antonio Ereditato, spokesman for the international group of researchers, said that measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done.

“We have high confidence in our results. We have checked and rechecked for anything that could have distorted our measurements but we found nothing,” he said. “We now want colleagues to check them independently.”

If confirmed, the discovery would undermine Albert Einstein’s 1905 theory of special relativity, which says that the speed of light is a “cosmic constant” and that nothing in the universe can travel faster.

That assertion, which has withstood over a century of testing, is one of the key elements of the so-called Standard Model of physics, which attempts to describe the way the universe and everything in it works.

The totally unexpected finding emerged from research by a physicists working on an experiment dubbed OPERA run jointly by the CERN particle research centre near Geneva and the Gran Sasso Laboratory in central Italy.

A total of 15,000 beams of neutrinos – tiny particles that pervade the cosmos – were fired over a period of three years from CERN towards Gran Sasso 730 (500 miles) km away, where they were picked up by giant detectors.

Light would have covered the distance in around 2.4 thousandths of a second, but the neutrinos took 60 nanoseconds – or 60 billionths of a second – less than light beams would have taken.

“It is a tiny difference,” said Ereditato, who also works at Berne University in Switzerland, “but conceptually it is incredibly important. The finding is so startling that, for the moment, everybody should be very prudent.”

Ereditato declined to speculate on what it might mean if other physicists, who will be officially informed of the discovery at a meeting in CERN on Friday, found that OPERA’s measurements were correct.

“I just don’t want to think of the implications,” he said. “We are scientists and work with what we know.”

Much science-fiction literature is based on the idea that, if the light-speed barrier can be overcome, time travel might theoretically become possible.

The existence of the neutrino, an elementary sub-atomic particle with a tiny amount of mass created in radioactive decay or in nuclear reactions such as those in the Sun, was first confirmed in 1934, but it still mystifies researchers.

It can pass through most matter undetected, even over long distances, and without being affected. Millions pass through the human body every day, scientists say.

To reach Gran Sasso, the neutrinos pushed out from a special installation at CERN – also home to the Large Hadron Collider probing the origins of the universe – have to pass through water, air and rock.

The underground Italian laboratory, some 120 km (75 miles) to the south of Rome, is the largest of its type in the world for particle physics and cosmic research.

Around 750 scientists from 22 different countries work there, attracted by the possibility of staging experiments in its three massive halls, protected from cosmic rays by some 1,400 metres (4,200 feet) of rock overhead.

Large Hadron Collider Created A Portal To Another Dimension?


As U.I.P stated recently, the bizarre UFO sighting in the sky above the Netherlands, looks VERY much like a Portal than anything else! Could it be that the Large Hadron Collider (LHC) has opened up a Portal in the sky to Another Dimension?

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Could it be that this image of a most bizarre looking object snapped up high above the Netherlands, could be the first ever picture of a portal to another dimension? Possibly opened up by the guys based in CERN

The Gentleman who caught this incredible sighting was Dutch snapper Harry Perton, who was photographing stormy evening skies at the tome over Groningen in his homeland, when all of a sudden there was a HUGE flash as he fired the shutter! Some people believe that this very well could be a wormhole to another Dimension.

Harry Perton's astonishing original picture

Harry Perton’s astonishing original picture

I am sure that a lot of you reading this will already know this, but Wormholes are a VERY mysterious scientific theory that there are openings in space-time to another part of the universe or even another dimension. It is very important to remember when discussing Portals/wormholes, that they are actually very real and even our silent friends in NASA not so long confirmed their existence

At the time he took the picture, Mr Perton actually did not realise anything out of the ordinary had just happened, and instead believing it must have been a flash of lightening instead. Little did he know that he may of taken one of the most important photos of all time…

It was only until a short while later after taking the photographs , when he reviewed the shots at home, he could actually see the strange semi-translucent object shaped like an upside down jellyfish or toadstool…..or Portal!

NASA's image or what a Portal could look like.

NASA’s image or what a Portal could look like.

The REAL thing!?

The REAL thing!?

You can clearly see that most of the object is a turquoise like colour, while there is a sunlight-esque jet or beam of light at the base…..Or an entrance to a portal to another Dimension!?

Not surprisingly, after this incredible photo was posted online, it led to a complete frenzy of speculation, which included whether it could be proof of wormholes, Project Blue Beam, alien visitations or even some kind of a religious warning to the people of this world. But the most popular theory was ‘could this be a portal to another Dimension?’

Has a new door for mankind been opened

Has a new door for mankind been opened

One commentator said about this whole strange event the:

“That’s a portal, it allows a craft to travel from one end of the universe to the other in a matter of secontnds. Someone made a mistake when entering our system and basically got caught. What you’re seeing is a craft entering not leaving.”

Many others immediately speculated that this could be the result of the Large Hadron Collider LHC being turned back on at twice its original power AND what with the confirmation off the guys at CERN that they are starting to look for other Universes/Dimensions!

Somebody else immediately posted: “It’s a wormhole.”

As we all know, the LHC is a massive atom smashing machine which scientists are now using to unlock secrets of the universe, which also includes whether parallel universes exist.

Many critics around the world now fear that CERN is tampering way too much with the laws of physics as they have already admitted that it could create a man made ‘mini’ black hole or even a wormhole – a mysterious theoretical portal through space-time to another part of the universe or even to another dimension….It really is like something from your wildest dreams and imagination as a child isn’t it!

Mr Perton officially responded to the amount of interest his image had gained around the world and said:

“I was taking photos and suddenly something flashed.

“I decided it must have been a strike of lightning ­ but back at home I saw something strange in one of the photos that I took ­what looked like a UFO.”

Quite a few other people online posted and decided that this could be a fighter jet sonic boom, or even a sign of the Second coming…or a sign of the End of days being not too far away! (well we did hear the sounds of the Trumpets in the sky across the world not so long ago).

One person in Malta has actually claimed that a whole football team saw it, and then adding:”We where playing a football game in Malta and all the 16 players saw it on 26th Tuesday around 8.05pm.”

Another claimed to have seen the same thing six years ago in Wales. Whilst others pointed out the Norway Spiral could be a similar oddity in the sky!?

However the bulk of people posting about this offered a more mundane explanation that it was an example of lens flare as the camera was being pointed towards the sun….but it doesn’t appear to be a particularly sunny day and I am no camera expert but surely you need a sun to cause ‘Lens flare’ The next thing we know it will start being called ‘The Netherlands Swamp gas’

However even though Mr Perton is getting an awful lot of attention for his photo, he still remains very sceptical, believing it is more likely a meteorological light trick.  But how can you explain the unexplainable!?

aaaa


U.I.P SUMMARY

As mentioned above us guys at U.I.P did suggest recently that this object in the sky was not a UFO but in fact had the look or a portal, and now many others are saying the exact same thing too!

You can clearly see that this object is definitely NOT a helicopter as some people have suggested and it is also most definitely not a camera lens flare which has also been mentioned…the fact the you would need the sun to be out to create a lens flare is quite an important fact too in this whole story.

We can obviously at this moment in time a 100% confirm what this is, but lets be honest with ourselves people, the Aliens have to come through somewhere and it has already been admitted by NASA that portals DO in fact exist….which quite possibly makes this photo one of the most famous captures to this date!

Could CERN of opened up a portal to another Dimension….quite possibly considering THIS is what they have confirmed that they are trying to do in their next phase of their project! But surely the risks are unknown of doing such a thing? Yep, and guess what the Scientists clearly have NO backup plan about what to do when they do open up the doors to another Dimension/Universe!?

We will keep you updated on this gripping and intriguing story….It is like the kind of thing we would once of only ever seen in the movies!

U.I.P

Other Dimensions About To Be Discovered?

Other Dimensions About To Be Discovered?

CERN has detected extremely rare particle decay for the first time .


These are the kinds of discoveries the Large Hadron Collider was built for.

 

Researchers working at CERN in Switzerland have detected a never-before-seen subatomic process that was “harder to find than the famous Higgs particle”, and it could make or break our understanding of the Universe.

By combining the results of two separate experiments at the Large Hadron Collider (LHC), the researchers were able to detect the extremely rare decay of a particle called the strange B (Bs) meson into two muons, something that the Standard Model of particle physics predicts will only occur about four times out of a billion – which is pretty much what the experiments found.

“It’s amazing that this theoretical prediction is so accurate and even more amazing that we can actually observe it at all,” one of the team, Sheldon Stone from Syracuse University in the US, said in a press release. “This is a great triumph for the LHC and both experiments.”

The findings, which have been published in Nature,came from the analysis of 2011 and 2012 data collected by the collider’s Compact Muon Solenoid (CMS) and Large Hadron Collider beauty (LHCb) experiments. Both of these study the properties of particles in order to poke holes in the Standard Model – the set of equations that we rely on to explain the behaviour and interactions of the particles in the Universe.

Although the Standard Model has dominated particle physics since the ’70s, it still doesn’t explain gravity, dark matter, or the behaviours of particles at the very beginning of the Universe, so scientists are always trying to find ways to test the limits of these equations and expand upon them.

To do this, they watch the decay of subatomic particles and compare the results with predictions from the Standard Model – any deviation could be evidence of new physics at play, such as new particles or forces that could help us understand some of the outstanding mysteries of the Universe. But so far, the predictions of the Standard Model have held up, with the discovery of the Higgs Boson being the most famous demonstration of this.

“Many theories that propose to extend the Standard Model also predict an increase in this Bs decay rate,” said Joel Butler Joel Butler, a physicist from the US’s Fermilab, who was involved in the CMS experiment. “This new result allows us to discount or severely limit the parameters of most of these theories. Any viable theory must predict a change small enough to be accommodated by the remaining uncertainty.”

However, while the Bs meson result “mostly matches” the Standard Model prediction, it deviated just enough to suggest that there may be something interesting going on that could be amplified by more data.

“It’s not way off the Standard Model prediction, but it’s low enough to keep us questioning,” said Butler. “We’ve been taking more data this spring and hope to eventually nail down the value. When we have two to four times more data from the next run of the LHC, things will start to get really interesting.”

Even more interesting is the fact that the researchers also detected evidence of the decay of another, even rarer type of B meson, known as the non-strange B meson, into two muons – something that’s predicted to occur only once out of every 10 billion decays. Again, the initial data mostly matches the predictions of the Standard Model, but with a lower confidence level.

The B mesons are fascinating to scientists because they could help explain why matter exists in the Universe at all. In theory, the Big Bang should have resulted in equal amounts of antimatter and matter, which should have annihilated each other on contact.

“Bs mesons oscillate between their matter and their antimatter counterparts, a process first discovered at Fermilab in 2006,” said Stone. “Studying the properties of B mesons will help us understand the imbalance of matter and antimatter in the Universe.”

With the LHC finally switching back on earlier this year, we’re excited to see what happens next.

Cern mulls huge physics machine.


The possibility of building an underground “atom-smasher” four times the size of the Large Hadron Collider is to be explored by experts.

The decision follows a high level meeting of scientists this week in Geneva, near the European particle physics centre, Cern.

LHC

The proposal is for a 100-km tunnel which would encircle the Swiss city.

It would reach to the Alps in the east, the Jura mountains in the west and even go under Lake Geneva.

Maps showing the proposed route reveal that it dwarfs the existing LHC, which is itself a world record beater as a science facility.

Dr Rolf Heuer, director general of Cern, who opened the meeting, argues it is already time to start thinking about what will follow the LHC, even though that machine has only been running a few years.

“We have very long lead times,” he explained, “because our projects are ambitious, and they need a lot of research and development.

“Take as an example the LHC. It is just three years into full swing, but the real discussions on the LHC started in 1983; the first meeting on the physics in 1984. And the first data were taken in 2009. So we need a long lead time. And that’s why we start now to kick off this project.”

The 100km Cern tunnel is just one of several proposals to be considered following the “kick-off” meeting being held this week. Japan and China are also interested in hosting giant international colliders, though the European advocates argue Cern’s established infrastructure would deliver substantial savings, and greater certainty over its success.

As well as the size and location of the collider, the particles to be smashed in it are also hotly debated.

New approaches

Some experts favour colliding protons, as is done in the LHC: Far higher energies can be reached using these, meaning researchers can explore higher extremes of conditions, more closely mimicking the Big Bang.

Paul Collier, head of beams at Cern, says the size of the Geneva basin is fortuitously right for such a machine. The aim is to reach energies about eight times higher than the 27-km-long LHC, at which point cornering round the bends of the tunnel becomes much harder for the speeding protons.

The larger radius and gentler curvature of the 100km tunnel, which just fits between the troublesome limestone either side of the basin, helps somewhat; and steering magnets, under development at Cern now, with twice the power of the LHC’s would do the rest.

Other experts, however, prefer using electrons, as were fired through the LHC’s predecessor, the LEP (the Large Electron Positron collider). These can be steered more easily, and give a far cleaner physics signal, meaning the complexities of interpretation that dog the LHC experiments can be avoided.

As to the value of building any experiment to succeed the LHC, Dr Heuer dismisses any suggestion that the discovery of the Higgs boson marks an end point to particle physics.

“By no means. We’ve only just begun,” he said.

“It took nearly 50 years to complete the so-called Standard Model, which just describes barely 5% of the Universe – the visible Universe. Fifty years for 5%! We still need to explore 95%, and this is what I would call the dark Universe.

“We very much hope that with the LHC running at higher energy next year, we might get the first glimpse of what dark matter is, for example. And building on that I would assume that we then can build a physics case for a future circular collider.”

Open questions

For Guido Tonelli, spokesperson for the CMS detector at Cern, when the Higgs discovery was underway, the essence of a physics case already existed.

“In my view – this is different from other scientists – I consider it important to start digging the new collider now, independent of what might be found at the LHC in the next few years,” he explained.

“If nothing appears in the next phase of the LHC, we have to move to higher energies, because there we might find solutions to the big questions that are still open.

“If we do find something, we know that at the LHC, we might be able to see the ‘tail of the dinosaur’, and we would need a machine with much higher energy to see the ‘entire animal’. So I accept we don’t yet know the details of the next accelerator; but the need for one is clear now.”

Rolf Heuer, only half jokingly, suggests the 100km proposal is modest by comparison with the Gothard Base rail tunnel (to run through the Swiss Alps) which is currently nearing completion and has three tunnels each measuring 57km long.

Cern civil engineer John Osborne, agrees the tunnelling shouldn’t be complex – using tunnel-boring machines as was done with the Channel Tunnel, the full length could be excavated in five or six years, he estimates. Though he concedes it would produce a lot of material that would have to disposed of.

“For the LHC tunnel, which was 27 km, we dug up about 1.5 million cubic metres of rock. And for that we managed to find local quarries that we could fill with all the excavated material.

“But for this tunnel, for which we don’t know all the dimensions, it would be substantially more – maybe 10 million cubic metres? So we do need to think about the environmental impact, and what we can do with this rock.”

Money, money, money

As to the price, no-one was prepared to venture a number. Perhaps because Rolf Heuer sternly advised the 350 participants not to.

“Any number you mention will be wrong,” he explained, “and worse it will be remembered forever.” And give the proponents a lot of trouble, he implied.

But he hopes to make the proposal affordable, by making a partnership across the world.

To that end, the next phase of the pilot study will be governed by a handful of leading experts from every region, to identify the feasibility of each proposal, identify the technology gaps, and the physics requirements. By the time it reports back, in about 5 years, the next set of results from the LHC should help settle on a conceptual design for a machine that might be built anywhere.

From there another five years to complete a detailed design, choose a site, and secure international approval and financing. And with 10 years to build and install the equipment, it might just be feasible to have a new machine ready when the LHC retires in 2035. Though the mood at the meeting was that is an optimistic timeline.

Paul Collier, head of beams at Cern, concedes the proposal might seem headstrong, but argues it is the rational route ahead for particle physics.

“There’s no point in doing small leaps when you invest in such a facility. If you take little steps, you will not get the value for money,” he said.

Another participant, approaching retirement himself, pointed out that the tunnel that now houses the LHC, and previously housed LEP was first discussed 40 years ago, and will still be in use in 20.

Likewise, the future collider will probably go through many incarnations, and still be running in 60 years.

He recalled a proverb he had to translate from Latin as a schoolchild: “He plants the seeds of trees he’ll never see bearing fruit.”

The Particle at the End of the Universe.


The difficulty of trying to explain the hunt for the Higgs boson shows that nature will not be so easily defined.
The Large Hadron Collider at Cern probably has another 20 years of use and further glories can be anticipated.

In the early 80s, the US decided to build a massive particle accelerator which was called – with typical American excess – the Superconducting Super Collider. During its early planning stages, the great machine was enthusiastically supported by the vast majority of US congressmen who each hoped the $4.4bn project would be based in his or her state, bringing jobs and prestige.

The Particle at the End of the Universe, by Sean Carroll The Particle at the End of the Universe: The Hunt for the Higgs and the Discovery of a New World, by Sean Carroll

Texas was eventually selected to be the SCC’s home – at Waxahachie, near Dallas. Forty-nine out of the 50 state delegations in Congress promptly dropped their interest in the SSC, leaving it fighting for its life. The Nobel laureate (and SCC defender) Steven Weinberg subsequently appeared on radio with a congressman who wanted to stop the project. “I explained that the collider was going to help us learn the laws of nature and asked if that didn’t deserve a high priority,” Weinberg recalls. “I remember every word of his answer. It was ‘No’.”

A few months later the SSC was cancelled and so Europe took over responsibility for the next-generation collider that physicists said they needed. The Large Hadron Collider – built at the laboratories of Cern, near Geneva – eventually began operations in 2009 when scientists started smashing beams of protons into each other to seek new sub-atomic entities in the debris. Three years later, they found the Higgs boson, the fabled particle responsible for giving mass to objects. Peter Higgs, a Brit, and the Belgian François Englert, who first proposed the particle’s existence, subsequently shared the 2013 Nobel prize for physics.

Crucially, the LHC probably has another 20 years of use and further glories can be anticipated – though Sean Carroll makes it clear that these are unlikely to bring wealth or vast industrial returns. We construct machines such as the LHC, and try to uncover the building blocks of the cosmos, primarily as cultural exercises, he argues in The Particle at the End of the Universe. “Basic science might not lead to immediate improvements in national defence or a cure for cancer but it enriches our lives by teaching us something about the universe of which were are a part,” he tells us. “That should be a very high priority indeed.”

It is a fair point though it begs the simple question: just what have we learned from the billions of euros we have invested in particle physics? What cultural benefits have they brought? A great deal, says Carroll. We now know that sub-atomic particles come in two varieties: fermions that make up matter, and bosons that carry forces. The latter include gluons, photons, gravitons (which carry gravity) and of course the Higgs. The former, the fermions, include leptons such as the electron and quarks of which there are six types: up, down, charm, strange, top and bottom. On top of that we have issues of symmetry, force fields and wave functions.

And that, I am afraid to say, is just the start, for as Carroll makes abundantly and wearisomely clear, these particles, forces and processes combine in highly complex, intricate ways, often inducing numbing incomprehension in the process. “Whenever we have symmetry that allows us to do independent transformations at different points (a gauge symmetry), it automatically comes with a connection field that lets us compare what is going on at those locations,” we are told at one point. I confess the sentence makes no sense to me despite several readings. Nor is it the only chunk of Carroll prose that left me reeling in bafflement.

To be fair to the author, he is dealing with a subject of mind-spinning complexity. Things get messy, he admits. “It’s not supposed to be simple; we’re talking about a series of discoveries that resulted in multiple Nobel prizes,” he states.

It is a good point and Carroll does try to pace his book carefully – at least during the opening sections. New concepts are introduced with restraint and, by adopting a light, slightly gossipy style, he occasionally lightens the reader’s load. On the work of the experimentalists at Cern who strive day and night to drive their machines to the limits, he tells us that “occasionally they are allowed to visit their families, or see the sun, though such frivolities are kept to a minimum”. That perfectly captures the intense, massive collaboration – involving thousands of scientists – that was required to build and run the Large Hadron Collider.

Unfortunately, such levity makes only rare appearances in a book that is sadly disfigured by the over-weaning ambition, of an otherwise talented author, to write the definitive account of the laws of nature for the layman. The resulting confusion suggests such an account is simply not feasible. Nature will not be so easily defined, it seems.

Physicists Now Want a Very Large Hadron Collider.


The proposed project’s accelerator ring would be 100 kilometers around and run at seven times the energy of the LHC

When Europe’s Large Hadron Collider(LHC) started up in 2008, particle physicists would not have dreamt of asking for something bigger until they got their US$5-billion machine to work. But with the 2012 discovery of the Higgs boson, the LHC has fulfilled its original promise — and physicists are beginning to get excited about designing a machine that might one day succeed it: the Very Large Hadron Collider (VLHC).

“It’s only prudent to try to sketch a vision decades into the future,” says Michael Peskin, a theoretical physicist at SLAC National Accelerator Laboratory in Menlo Park, California, who presented the VLHC concept to a US government advisory panel on 2 November.

The giant machine would dwarf all of its predecessors (see ‘Lord of the rings’). It would collide protons at energies around 100 teraelectronvolts (TeV), compared with the planned 14 TeV of the LHC at CERN, Europe’s particle-physics lab near Geneva in Switzerland. And it would require a tunnel 80–100 kilometers around, compared with the LHC’s 27-km circumference. For the past decade or so, there has been little research money available worldwide to develop the concept. But this summer, at the Snowmass meeting in Minneapolis, Minnesota — where hundreds of particle physicists assembled to dream up machines for their field’s long-term future — the VLHC concept stood out as a favorite.

Some physicists caution that the VLHC would be only a small part of the global particle-physics agenda. Other priorities include: upgrading the LHC, which shut down in February for two years to boost its energies from 7 TeV to 14 TeV; plans to build an International Linear Collider in Japan, to collide beams of electrons and positrons as a complement to the LHC’s proton findings; and a major US project to exploit high-intensity neutrino beams generated at the Fermi National Accelerator Laboratory in Batavia, Illinois. Jonathan Rosner, a particle physicist at the University of Chicago, Illinois, who convened Snowmass, says that these forthcoming projects should be the focus. “It’s premature to highlight the VLHC,” he says.

In some ways, the interest in the VLHC is a sign that particle physicists are returning to their roots, pushing to ever higher energies to find the fundamental building blocks of nature.

They will have to justify it, however. The discovery of the Higgs particle lends support to the idea that some particles have mass because they interact with a pervasive, treacle-like Higgs field. Yet many aspects of the discovery are still not understood, including why the mass of the Higgs particle is so large. One way of explaining its heaviness is through supersymmetry theory, in which known particles are coupled with heavier ones that might be observed in bigger particle colliders. Although the LHC has not detected any signs of supersymmetry, Peskin hopes that a hint may come before the end of the decade, which would help to inform the design of a larger machine.

One advocate of a bigger machine is Nima Arkani-Hamed, a theoretical physicist at the Institute for Advanced Study in Princeton, New Jersey. In December, he will help to launch an institute in Beijing called the Center for Future High Energy Physics. Part of its explicit mission, he says, is to explore the physics that a future proton collider might investigate. William Barletta, an accelerator physicist at the Massachusetts Institute of Technology in Cambridge, says that this work is crucial to identify a machine size that will maximize the science per dollar. “We won’t just give hand-waving arguments,” he says.

To build a 100-TeV machine, Barletta adds, physicists will need to develop superconducting magnets that can operate at higher fields than the current generation, perhaps 20 tesla instead of 14 tesla. One leading candidate material for such magnets is niobium tin, which can withstand higher fields but is expensive and must be cooled below 18 kelvin.

CERN is developing its own plans for a collider that is similar to the VLHC. CERN accelerator physicist Michael Benedikt is leading a study of a ‘very high energy large hadron collider’ that would pass under Lake Geneva. It would have the same key parameters as the suggested VLHC: a circumference of 80–100 km and a collision energy of 100 TeV. Benedikt suggests that construction might begin in the 2020s so that the machine could be completed soon after the LHC shuts down for good around 2035. “One would not want to end up with a huge gap for high-energy physics,” he says. He adds that it is too early to offer a price tag. But other physicists speculate that a next-generation collider would have to cost less than $10 billion for the project to be politically plausible.

NOBEL PRIZE IN PHYSICS 2013.


The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2013 to

François Englert 
Université Libre de Bruxelles, Brussels, Belgium

and

Peter W. Higgs
University of Edinburgh, UK

“for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider

Here, at last!

François Englert and Peter W. Higgs are jointly awarded the Nobel Prize in Physics 2013 for the theory of how particles acquire mass. In 1964, they proposed the theory independently of each other (Englert together with his now deceased colleague Robert Brout). In 2012, their ideas were confirmed by the discovery of a so called Higgs particle at the CERN laboratory outside Geneva in Switzerland..

The awarded theory is a central part of the Standard Model of particle physics that describes how the world is constructed. According to the Standard Model, everything, from flowers and people to stars and planets, consists of just a few building blocks: matter particles. These particles are governed by forces mediated by force particles that make sure everything works as it should.

The entire Standard Model also rests on the existence of a special kind of particle: the Higgs particle. This particle originates from an invisible field that fills up all space. Even when the universe seems empty this field is there. Without it, we would not exist, because it is from contact with the field that particles acquire mass. The theory proposed by Englert and Higgs describes this process.

On 4 July 2012, at the CERN laboratory for particle physics, the theory was confirmed by the discovery of a Higgs particle. CERN’s particle collider, LHC (Large Hadron Collider), is probably the largest and the most complex machine ever constructed by humans. Two research groups of some 3,000 scientists each, ATLAS and CMS, managed to extract the Higgs particle from billions of particle collisions in the LHC.

Even though it is a great achievement to have found the Higgs particle — the missing piece in the Standard Model puzzle — the Standard Model is not the final piece in the cosmic puzzle. One of the reasons for this is that the Standard Model treats certain particles, neutrinos, as being virtually massless, whereas recent studies show that they actually do have mass. Another reason is that the model only describes visible matter, which only accounts for one fifth of all matter in the cosmos. To find the mysterious dark matter is one of the objectives as scientists continue the chase of unknown particles at CERN.