Quantum fluctuations in science, space and society, from quarks to Hubble and Mars. Served up by Alan Boyle, NBC News Digital science editor. E-mail Alan, or connect via Facebook, Twitter or Google+.
Columbia mathematician Peter Woit reports rumblings to the effect that evidence of the elusive Higgs boson has been detected at the Large Hadron Collider around the energy level of 125 billion electron volts. Similar rumblings are popping up on viXra.org and elsewhere. "This looks to be still not a conclusive Higgs signal, but the closest thing yet," Woit writes. All eyes ... at least all eyes that have been focused on the Higgs quest .. are turning to a public seminar scheduled at CERN on Dec. 13. For more about the significance of the Higgs boson, check out this week's interview with Oxford physicist Frank Close, author of "The Infinity Puzzle."
Lead-ion collisions recorded by the Large Hadron Collider's ALICE detector during this month's run show up in green on this graphic. Oxford physicist Frank Close says the LHC could solve cosmic puzzles.
Close traces the decades-long effort to find the deep connections between the fundamental forces of nature and resolve the "infinity puzzle" — that is, the fact that the mathematics of quantum theory came up with nonsensical numbers. That puzzle was eventually solved, as Close describes in the book, but an even bigger puzzle remains: Why is the cosmos built the way it is?
Some clues could emerge from Europe's Large Hadron Collider, where physicists are looking for a mysterious particle known as the Higgs boson. Close delves into the strange role that the Higgs plays in contemporary physics, but he emphasizes that his latest book is about much more than the science.
"'The Infinity Puzzle' is not just another story about the physics of the LHC," he told me this week. "It's focusing on the people. Science is a pure ideal, but the scientists who do it are people. And we all have the same desires and pressures. ... There are heroes and villains in science, as there are everywhere."
Close's tale illustrates that the course of true science doesn't always run smooth. It may well turn out that the long-sought Higgs boson is a will-o'-the-wisp, and physicists will have to go back to square one. But even that won't render "The Infinity Puzzle" out of date.
"If the Higgs boson turns out not to exist, and we have to completely rewrite everything, this book will show how we got to this conundrum," Close said. "And if it does exist, hopefully it will explain why it was so important."
The book is particularly timely, considering that this year's Nobel Prize ceremonies are due to take place in Stockholm and Oslo next week. During a wide-ranging interview, Close discussed his book as well as the people and the puzzles that inspired it. Here's an edited version of the Q&A:
Cosmic Log: Could you explain what the "infinity puzzle" is?
Frank Close: The Large Hadron Collider at CERN is the biggest experiment that particle physics has ever set out to do. It's trying to find the answer to why there is structure in the universe. The buzzword you hear is the Higgs boson, and the question is, who is Higgs, what's the boson, what's it all about?
Well, what it's all about is what "The Infinity Puzzle" is trying to answer. In telling the story, the book focuses on the people who brought us to this remarkable point in history. And in particular it focuses on a group of scientists who discovered two separate things, half a century ago. First, how to unite the electromagnetic force, the force that holds you and me together and makes magnets work, with the weak force of radioactivity, which plays a very important part in how the sun burns. This is called the electroweak theory today.
The other part of the story is how to make a theory, which works beautifully if there is no mass in anything at all, work in a world where particles have mass. That has become known as the Higgs mechanism, and the consummate object we're looking for is the Higgs boson. The questions surrounding whether these things are named correctly, whether the people who won Nobel Prizes in the past were the right people, and whether there are going to be controversies over Nobel Prizes in the future for all of these things — those are the themes of the book. It's about the politics of science, the way that people are driven to want to get the big prizes. Scientists suffer the same emotions that everybody else does.
Q: You touch on many of those personalities — some who received Nobels, and some who didn't but deserved to. Do those personalities actually shape the science? Are there things in the universe that we see in a particular way just because a scientist first described it in that way?
A: It's a very interesting question about the role of personality in being able to tease out the secrets of nature. There are some people who are strong mathematical calculators but don't necessarily have great vision. There are other people who have got great vision, but aren't particularly strong calculators. It's when these two types get together that rapid progress is often made.
Frank Close, author of "The Infinity Puzzle," talks about the story of the men whose breakthroughs led to the Large Hadron Collider.
Ultimately, there's a truth out there, and we're trying to find what it is. It's different for artists. If you're a Beethoven, if you're proposing some symphony and you don't publish it, the chance that somebody else will create the very same symphony someday ... well, that just doesn't happen. But in the case of science, nature has already constructed the symphony, and we're trying to find what it is.
The challenge is, suppose that you have uncovered a bit of the symphony, but you're not sure whether you want to go public with it, so you don't publish it. Then, a short time later, somebody else does publish it, a bit braver than you, and you realize that you were right all along. You've lost the credit. There's a certain point where you have to be brave enough to jump off the diving board and take the plunge, to mix in another metaphor. There are many examples of people who didn't take that last step, for one reason or another. You know the names of the winners, but you don't know the ones who didn't quite make it.
Q: When it comes to the Higgs boson, the question has arisen as to whether it actually exists. One of my colleagues has joked that if it's found, that's worth a Nobel. And if it's ruled out, that's worth a Nobel as well. Is that the way it works?
A: The idea that has led to the Higgs boson is a piece of beautiful mathematics. Whether nature actually does it is a question that only experiments can answer. Although the theorists are the ones that get all the press ... the Einsteins and the other names that trip off the tongue ... it's ultimately the experiments that decide. That's where we are at the moment.
The idea that there should be a Higgs boson, or something else that masquerades as that particle, has been around for a long time. It's only now that are finally able to do the experiments that will tell us one way or the other if that is the case. And if it is the case, we might find out exactly how nature plays this particular trick. When Peter Higgs and a group of other people first put the idea forward, they were trying to solve a particular conundrum, and they came up with the simplest way of doing it — that is, that there was a single particle known as the Higgs boson. That was 50 years ago. Since then, people have refined those original ideas, based on the discoveries we have made.
Basic Books
Oxford physicist Frank Close's book traces the decades-long quest to solve one of the biggest puzzles of quantum physics.
There are several possible ideas as to how nature might actually do this conjuring trick. It might be there's a whole family of particles called Higgsinos and other weird names. It might not be a simple particle. It might be a compound — just as an atom has a nucleus that's made of protons and neutrons, which are made of smaller things called quarks, there might be new sorts of particles waiting to be found, called techniquarks, which collectively act as if they were a single boson.
It might be those, it might be something else. We simply don't know. And that's the exciting thing. Nature knows the answer at the moment, and we're trying to find out at last what it is.
Q: Is the Higgs boson the only door to new physics, or are there other routes to going beyond the Standard Model of physics?
A: We certainly know that the Standard Model cannot be the final answer. It describes everything that we currently have explored, but there are many things we have to put in by hand. The mass of the electron is put in by hand. Why it is what it is, we don't know. But if it were different, we wouldn't be having this conversation. You start by putting in all these measured numbers, and then we can describe a vast amount of stuff. But there must be some richer theory out there that will show why the Standard Model is as it is.
An analogy is Newton's laws of mechanics, which worked perfectly for hundreds of years. They were later incorporated inside Einstein's theory of relativity, which is a much richer, more powerful theory that includes Newton in it. We suspect there is a "theory of everything" out there which will contain the Standard Model. We are hoping we'll get close to the nature of that theory at the Large Hadron Collider. The LHC is exploring regions of nature we've never been able to explore before. We've seen them from afar — it's a bit like knowing there's somebody around the corner but you haven't seen them yet.
We are entering new territory. We're creating in the laboratory the conditions that the universe experienced about a trillionth of a second after the big bang. There are observations that have taken us to a billionth of a second after the big bang, so we've been pretty near. You might think, "Oh, why would we want to get nearer?" It's because the stuff that you and I are made of was created in that cauldron of the big bang's aftermath, and there are puzzles yet to be solved.
For example, why is anything left today? Antimatter is real, and matter and antimatter annihilate when they meet. So why didn't the newborn universe annihilate itself after the big bang. There must be something that tipped the balance. What that is, we don't know for sure, but some hints are beginning to emerge from the Large Hadron Collider.
The real thing is, we're exploring a new continent, and the LHC will show us what is there. That will then answer many of these questions —and if I knew the answers now, I'd be riding off to Stockholm.
Q: You mentioned the fact that some of the values in the Standard Model have to be put in by hand, and that scientists are trying to find out if there's a deeper theory that explains why those values are as they are. Some physicists have said that it might just be a lucky break that we have those values, and that our universe might be merely one of the "bubbles" sitting on the wider landscape of the multiverse. Do you subscribe to that landscape view of the multiverse?
A: Well, of course, the simple answer is, I don't know. And to be honest, nobody knows. I feel sometimes it's a bit of a cop-out. The universe I find myself in is difficult enough to describe. The idea that it is one of a huge number of universes ... that might indeed be true, but if we cannot experimentally answer whether it is true or not, I'm not sure whether the question is actually scientific. It's interesting philosophically. It's possible that someday we might be able to come up with an experiment that can answer whether there are other universes, but then you get into interesting tautological questions. The "universe" is presumably everything we can be aware of. If there are other universes that we cannot be aware of, then they're beyond the capability of science to investigate. But if they are investigatable through science, they are in a sense part of our universe.
The real question is this: Are the masses of electrons and other fundamental particles essential numbers in their own right, or are they no more fundamental than the radii of the planets around the sun? We don't know yet. I can't imagine anything that the Large Hadron Collider will discover that will give us a clear insight as to why particles have the masses that they do. But if we discover the Higgs boson, or whatever it is, we may well find out where mass comes from. And there may be some interesting quirk that comes out of that discovery that will give us a clue as to why the masses are as they are. The excitement of science is that until you've done it, you don't know.
Q: It seems to me that you were on a BBC program some years ago that touched on this whole discussion over whether a particle collider could destroy the world.
A: Yes, and the world hasn't ended yet.
Q: Some people would say the controversy was actually good for physics because it was a "teachable moment" that got people interested in physics. How do you see it?
A: Well, to be fair, it was a controversy that no scientist really subscribed to. It was something that somebody dreamt up, and it created an interesting sensation. But it does give the opportunity to explain what the Large Hadron Collider is and is not. The idea that we are doing things in the Large Hadron Collider that have never been done before is not the case. It's the first time that we have been able to do them. But the universe at large has collided particles together at energies far in excess of anything we do at the LHC or will ever be able to do. Cosmic rays in outer space are subatomic particles whipped into violent motion by magnetic fields in the cosmos — and they hit the upper atmosphere at energies far in excess of anything at the LHC.
Nature has done the experiments before, and we're still here. It's just the first time that we have been doing them under controlled conditions to tease things out. There are more things in life to worry about than that.
The detectors of the OPERA experiment to measure neutrinos rise from the floor of the Italian National Institute of Nuclear Physics INFN's Gran Sasso Laboratory. Two human figures on the left and right edges of the picture provide a sense of scale.
By Alan Boyle, Science Editor, NBC News
Researchers say new tests have confirmed earlier indications that neutrinos can travel faster than light, but not everyone is convinced.
The claim runs so counter to a century's worth of physics that most observers won't be content until the findings from the OPERA experiment are repeated under a variety of conditions, by different teams of researchers. If the results hold up, that would require a reinterpretation of Albert Einstein's special theory of relativity, which effectively sets the velocity of light in a vacuum as a cosmic speed limit.
"A measurement so delicate and carrying a profound implication [for] physics requires an extraordinary level of scrutiny," Fernando Ferroni, president of the Italian Institute for Nuclear Physics, or INFN, said in a news release. "The experiment OPERA, thanks to a specially adapted CERN beam, has made an important test of consistency of its result. The positive outcome of the test makes us more confident in the result, although the final word can only be said by analogous measurements performed elsewhere in the world."
"OPERA" is a tortured acronym that stands for "Oscillation Project with Emulsion-tRacking Apparatus." The team's researchers shoot beams of neutrinos from the CERN particle-physics center on the French-Swiss border to INFN's Gran Sasso Laboratory, more than 450 miles (730 kilometers) away. The travel time for each pulse of neutrinos is measured to an accuracy of billionths of a second. In the faster-than-light experiment, the researchers reported that the neutrinos arrived 60 nanoseconds earlier than a light beam would have.
The revised experiment sent out 3-nanosecond-long bursts of neutrinos, spaced by as much as 524 nanoseconds, INFN said. "This permits to make a more accurate measure of their velocity, at the price of a much lower beam intensity; only 20 clean events have been collected by OPERA in this phase. Additional events could be eventually collected in the next year run," the institute said.
The Associated Press reports on the faster-than-light neutrino research.
Jacques Martino, director of France's National Institute of Nuclear and Particle Physics at CNRS, was quoted as saying that the search for potential experimental errors "is not over."
"There are more checks of systematics currently under discussion," he said. "One of them could be a synchronization of the time reference at CERN and Gran Sasso independently from GPS, using possibly a fiber [cable]."
Some physicists criticized the initial experiment because they thought it did not fully account for the relativistic effects of the Global Positioning System, which was used to track the elapsed time as well as the distance traveled between CERN and Gran Sasso.
INFN said the updated results have been submitted for review and publication in the Journal of High Energy Physics. But ScienceInsider's Edwin Cartlidge reported that about 15 of the experiment's nearly 200 collaborators have declined to lend their names to the journal submission, on the grounds that further confirmation is required.
An unnamed source on the OPERA team told ScienceInsider that the controversy over the faster-than-light findings was exhausting. "Everyone should be convinced that the result is real, and they are not," the source was quoted as saying.
Other researchers, including physicists with the MINOS experiment at Fermilab, are working up independent analyses of neutrino runs to assess the OPERA team's findings. The initial outside assessments are expected to become available within six months or so, but end-to-end replications of the experiment could take significantly longer.
Update for 2 p.m. ET Nov. 18: In response to some of the comments below, I've changed the headline on this item, which originally read "Faster-than-light neutrinos confirmed." I realize the new headline still implies that superluminal neutrinos actually exist even though the evidence for that is in dispute, but I hope you'll understand that this is shorthand for "New experiment continues to support hypothesis about faster-than-light neutrino travel."
Commentators have been surprisingly fast to point to faster-than-light neutrinos as evidence that scientists could be wrong about lots of things, including the causes of climate change. But the most likely scenario is that special relativity — a theory that contends nothing can be accelerated beyond the speed of light in a vacuum — will turn out to be right. Or at least relatively right.
Two weeks after the neutrino experiments first came to light, the prevailing view among physicists is that the observations will somehow be shown to be wrong. The time measurements had to be made to an accuracy of billionths of a second. Synchronizing the time signatures over a distance of more than 450 miles of neutrino flight, from the CERN particle-physics center on the French-Swiss border to Italy's Gran Sasso National Laboratory, is extremely challenging.
Nature News cites one paper questioning whether the clock synchronizations accounted for the varying gravitational force as the neutrinos sped through the planet. General relativity's gravitational time-dilation effect might have reduced the precision of the measurements, Imperial College London's Carlo Contaldi suggested. This wouldn't be the first time that special relativity and general relativity got tangled up with each other: The satellite-based GPS navigation system has to account not only for special relativity (which would make the satellite's clocks look as if they're moving slower from the perspective of earthly clocks) but also for general relativity (which would make them seem to move faster).
Other researchers have wondered whether fluctuations in the composition of the neutrino beam are just making it seem as if some of the particles are flying faster than light, when the effect is actually being caused by those unaccounted-for fluctuations. Nobel laureate Sheldon Glashow and a colleague at Boston University, Andrew Cohen, take another tack: They say the OPERA neutrino beam doesn't bear the energy signature that it should have if the particles were exceeding the speed of light.
The leaders of the OPERA collaboration, the team that made the neutrino observations, say they've accounted for the factors that have come to light so far, including the clock-synchronization issue. But Physics World reports that up to half of the collaboration's members think it's premature to submit their findings to a scientific journal for formal publication. (So far, the results have been posted only to the ArXiv.org preprint server.)
While the OPERA physicists continue to double-check and debate their results, researchers from the U.S.-based MINOS collaboration are gearing up to do an independent neutrino-timing check. Re-analyzing the existing MINOS data is expected to take up to six months, and if new experiments are required, that could take more than a year. In the meantime, physicists will continue trying to poke holes in the OPERA observations.
Neutrinos on the air During this week's "Virtually Speaking Science" chat, Caltech theoretical physicist Sean M. Carroll told me that OPERA's results are "almost certainly not true."
"Even the people who did the experiment will tell you that the chances are very, very small that it's right," Carroll said. "They just want people to understand that it's on the table, it's possible. They don't know what's wrong with their experiment. They would like someone else to check it, to duplicate it, to see what might be wrong."
If the observations turn out to be right, the implications would be "incredibly groundbreaking and earth-shattering," he said. But they wouldn't be beyond the power of theorists to explain, even within the framework of relativity.
"This is what we do," Carroll said. "We come up with new theories that fit crazy, unexpected pieces of data like this."
The OPERA experiment has already given rise to scores of papers on the ArXiv server, many aimed at explaining why the results aren't as crazy as they look. If the results hold up, theorists would have to adapt Albert Einstein's special relativity theory to accommodate faster-than-light observations. But Carroll says they wouldn't start from square one.
"We can say with confidence that there is some sense in which Einstein was right. He might not be the final word, but he wasn't absolutely wrong," he said. "Einstein's theories are not wrong, they've been tested right and left, and there's something right about them. They might need to be improved, they might need to be added to. ... But we're not throwing everything out and starting from scratch."
"I wrote a speed-of-light joke ... but a neutrino beat me to it."
Carroll says that faster-than-light neutrinos would not necessarily disrupt causality and the arrow of time, and he explains why in a posting to his blog titled "Can Neutrinos Kill Their Own Grandfathers?"
"It could be true, but it doesn't have to be true. ... Theorists would have a lot of fun figuring out how the world actually works in that case," he said.
For an hourlong discussion of faster-than-light research as well as other weird frontiers of physics, including the Nobel-winning studies of our accelerating universe, listen to the full "Virtually Speaking Science" podcasts, either online or as an MP3 download. If you're a resident of the Second Life virtual world, you'll also enjoy Saturday's talk on dark energy, presented at 10 a.m. PT / SLT by the Meta Institute for Computational Astrophysics.
The climate connection Particle physics and climate science rarely mix, but they did get mixed up this week in an opinion piece written for The Wall Street Journal by Robert Bryce, a senior fellow at the Manhattan Institute. The essay listed "five obvious truths about the climate-change issue," including this one as No. 5:
"The science is not settled, not by a long shot. Last month, scientists at CERN, the prestigious high-energy physics lab in Switzerland, reported that neutrinos might — repeat, might — travel faster than the speed of light. If serious scientists can question Einstein's theory of relativity, then there must be room for debate about the workings and complexities of the Earth's atmosphere."
That argument earned almost instant derision from the science-minded Twitterverse, spawning #WSJscience as a new hashtag. The idea that one weird experimental claim proves that other, completely unrelated scientific claims are shaky came off as laughable. The classic construction for #WSJscience tweets goes like this: "If serious scientists can question relativity, there must be room to debate [whether Earth goes around sun]." (Hat tip to @cqchoi)
Rather than engaging in an extended rant myself, let me just link to a few of the rants elsewhere on the Web, plus a few totally serious articles about the frontiers of physics.
Msnbc's Thomas Roberts talks with astronomer Derrick Pitts about the Higgs boson.
By Alan Boyle, Science Editor, NBC News
The latest results from Europe's Large Hadron Collider have raised hopes among particle physicists that the elusive Higgs boson — also known as the "God Particle" — may be coming to light at last.
Sure, we've heard that before: Rumors about a possible detection at Fermilab's Tevatron, a particle collider near Chicago, have been circulating since last year, and just in the past few months there's been a rise and fall in expectations that the Higgs would turn up in the Tevatron's data.
Now the potential signature of the Higgs boson has turned up in an avalanche of data from both of the Higgs-hunting detectors at the Large Hadron Collider. The signature is not yet clear enough to constitute a discovery, but it suggests that the $10 billion particle collider, arguably the biggest and costliest science experiment on Earth, just might be on the right track.
"We cannot say anything today, but clearly it's intriguing," Fabiola Gianotti, spokeswoman for the science team behind the LHC's ATLAS detector, told The Guardian. Similarly intriguing results were reported by the team for the other detector, the Compact Muon Solenoid or CMS.
The two sets of findings were reported independently on Friday at the Europhysics Conference on High-Energy Physics in Grenoble, France, one of the world's biggest particle-physics forums. The ATLAS and CMS teams have been sorting through billions upon billions of data points from proton collisions at the LHC, looking for the statistical signs that suggest Higgs bosons are being shaken free for tiny fractions of a second.
The newly reported analyses suggest that the type of Higgs boson predicted by Standard Model of particle physics could be turning up around the mass-energy level of 140 billion electron volts, or 140 GeV. That's about the same level reported by one of the Tevatron's research teams.
When it comes to statistical significance, the results are not yet solid enough to constitute a confirmed discovery. But the fact that multiple detectors at two colliders are coming up with similar "bumps" in their data is nevertheless generating excitement.
"No reputable scientist is going to tell you anything more than 'this is very, very interesting and we'll keep an eye on it.' But it is indeed very, very interesting," Fermilab's Donald Lincoln, a member of the CMS collaboration at the LHC as well as the Tevatron's DZero collaboration, told me in an email.
Some are not yet convinced. The University of Padua's Tommaso Dorigo, who is part of the CMS team as well as the Tevatron's CDF team, said he doesn't see "anything compelling" in regards to the Higgs' potential detection. Rather, he sees the results as more significant for identifying energy levels where the Standard Model Higgs almost certainly won't be found. But everyone who's in the know pretty much agrees that it won't be long before physicists can say definitively whether the kind of Higgs particle they've been looking for does or does not exist.
"While I'd hate to predict an exact date, it's pretty clear from the performance seen thus and the expected near future that the Higgs will be found or ruled out on a time scale of months or perhaps a year," said Lincoln, author of the book "The Quantum Frontier."
What's so big about the Higgs? Detecting the Higgs boson would be a big deal: It's the main reason why the Large Hadron Collider was built in the first place.
The LHC circulates protons around a 17-mile-round (27-kilometer-round) underground tunnel on the French-Swiss border to nearly the speed of light, and smashes them together within the giant ATLAS and LHC detectors as well as other special-purpose detectors distributed around the collider ring.
The more exotic products of those collisions almost instantly decay into more common subatomic particles, but by analyzing the distributions, directions and velocities of those particles, physicists can theoretically untangle big mysteries ranging from the origins of the universe to the nature of dark matter and the potential existence of extra dimensions in the cosmos.
The Higgs boson, and its associated field, is one of those big mysteries. Back in the 1960s, British physicist Peter Higgs and others proposed the boson's existence as the answer to a theoretical question about the nature of particle mass.
It's long been known that some particles (such as the quarks and leptons that make up matter) have mass, while others (such as the photon) are massless. But there was no solid explanation for the difference.
Higgs and his colleagues suggested that a type of field — analogous to a magnetic field — affected different particles in different ways, imparting mass to some particles but not to others.
In particle physics, fields are associated with force-carrying particles, which are put in a category of particles known as bosons. The particle associated with the Higgs field came to be known as the Higgs boson. Nobel-winning physicist Leon Lederman nicknamed it the "God Particle" because it played a central but subtle role in our conception of the cosmos. (Higgs and many other physicists hate the nickname.)
Fermilab scientist Don Lincoln describes the nature of the Higgs boson.
If the Higgs boson is found, and if it behaves in a manner consistent with the Standard Model, that would serve as an exciting validation of our current view of the structure of the cosmos. If the Higgs isn't found, or if it behaves in a non-standard way, that could be even more exciting. Physicists would have to go back to the drawing board and modify their explanation for the workings of the universe.
It's hard to predict how going back to the drawing board might affect the scientific world, or our everyday lives ... but the last time this sort of thing happened was a little more than a century ago, when quantum mechanics and relativity had to be invented to explain phenomena that just seemed weird to 19th-century physicists. These scientific paradigm shifts opened the way to innovations ranging from atom bombs and nuclear power to microwave ovens and lasers. So who knows where post-Standard Model physics might lead?
The details of discovery Here's one more important thing to keep in mind: Discovering the Higgs won't be like discovering a new continent. Lots of numbers have to be crunched, and lots of statistics have to be analyzed to tease out the evidence for a previously undetected particle.
"It's much more like walking toward people in the fog, and waiting for the moment when you recognize the person you're looking for," Lincoln told me. The process that's playing out right now is probably the way discoveries work in 21st-century physics: First there are hints that something interesting might be going on, then more data are deciphered to confirm a discovery, and then physicists finally figure out how that knowledge can be put to use.
With that in mind, here's how Lincoln explains the slight "bump" seen in the newly reported data from the Compact Muon Solenoid:
M. Krammer et al. / CMS / CERN
This chart shows how data from the Large Hadron Collider's Compact Muon Solenoid may suggest the existence (or non-existence) of the Higgs boson at particular mass-energy levels (on the horizontal axis, in terms of giga electron volts, or GeV).
"Take a look at the image above. There are a couple of important things. First, there's a horizontal red line. This is the Standard Model. If the black or blue line goes below the red line, the Standard Model version of the Higgs boson is ruled out for that mass. So, except for some wiggles, the Standard Model Higgs is ruled out from about 150 billion electron volts, or 150 GeV, to 460 or so.
"The thing that is getting people a little excited is the second feature. The dashed black line is how well we expect to do if the Standard Model is right, but the Higgs boson doesn't exist. When the blue and black lines start to drift away from the dashed black line, it means that we expect we can rule out more than we did. For instance, in this case, we expected to be able to rule out from about 125 GeV and up. But since the blue and black lines don't dip below the red lines until 145 or 150 or so, this could mean that we have more events than physicists would expect to see from the Standard Model without the Higgs. So that could mean there are some Higgs events floating around. The difference is biggest around 145 GeV or so.
"Now we get a reality check. The green and yellow bands indicate our uncertainty in our expectations. So we see that the black and blue lines are at the edge of our uncertainty. Further, even in the region we are excluding (near 160 GeV), there is an excess (observed above expectation).
"This means (to me at least, and at this point it's all a matter of judgment) that it could be that the discrepancy reflects an imperfect understanding of the detector and algorithms.
"Still, all of the experiments sees an excess at some level, suggesting that either our theory has been implemented incorrectly or maybe something is going on. No reputable scientist is going to tell you anything more than 'this is very, very interesting and we'll keep an eye on it.' But it is indeed very, very, interesting.
"At the Lepton/Photon conference to be held in a month in Mumbai, the ATLAS and CMS experiments will hopefully combine their results, effectively doubling the amount of beam being used."
Now that you've gotten the hang of reading the data, here's the corresponding chart from the ATLAS detector.
The bracketed areas indicate mass-energy regions where the Standard Model Higgs has been excluded: 155 to 190 GeV and 295 to 450 GeV.
If you look ever so closely at the chart, you'll notice a slight elevation of the black line above the yellow zone of uncertainty at about 140 GeV, the same area where the CMS team detected the potential signature of a Standard Model Higgs boson:
K. Cranmer / NYU / ATLAS / CERN
This plot shows readings from the ATLAS detector that hint at mass-energy levels where the Standard Model Higgs boson might (and cannot) be found. The brackets indicate exclusion zones from roughly 155 to 190 GeV and from 295 to 450 GeV.
The bottom line? Something interesting may be going on in the world of physics, although there's still a chance that results or theories are being misinterpreted. Within the next year or so, we should know whether we're in the midst of a cosmic discovery. Stay tuned ...
Update for 6:05 p.m. ET July 25: The director general of the organization that hosts the LHC — known as the European Organization for Nuclear Research or CERN — says he expects the question of the Higgs boson's existence to be solved by the end of 2012. "I would say we can settle the question, the Shakespearean question — 'to be or not to be' — end of next year," Director General Rolf Heuer told reporters at the Grenoble conference.
Correction for 11:10 a.m. ET July 26: I've corrected the name of the ATLAS collaboration's spokeswoman, which I scrambled up as I was writing this item. Mi dispiace!
Technicians check the photomultiplier tubes that ring an underground cylindrical stainless steel tank known as the Super-Kamiokande detector. The detector is on watch for faint glimmers of radiation from exotic particles zipping through the earth.
By Alan Boyle, Science Editor, NBC News
Can one particle explain both dark matter and the mysterious origins of matter and antimatter? Some physicists think so. They're calling the as-yet-only-theoretical object the "X particle."
Physicists from Canada's TRIUMF particle-physics facility, the University of British Columbia and Brookhaven National Laboratory laid out their ideas on the X particle in a paper published last month by Physical Review Letters -- and since then, the ideas have been picked up by PhysicsWorld magazine as well as Discovery News. (You can read a full draft of the paper on the arxiv.org website.)
The concept addresses two of the deep mysteries in modern physics:
Dark matter: Observations of distant galaxies and galaxy clusters suggest that the matter we can see accounts for about a fifth of their gravitational mass. The other four-fifths is thought to exist in the form of exotic matter than can be detected only by its gravitational effect. So what is that stuff?
Matter vs. antimatter: Theory dictates that equal amounts of matter and antimatter must have existed at the beginning of the universe -- and yet, we see lots of matter and virtually no antimatter in the universe today. What happened to the antimatter, and why did matter win out?
The physicists suggest that X particles and anti-X particles -- each with about 1,000 times as much mass as a proton -- existed in the early universe. Such particles would show a "yin-yang" pattern of decay. Theoretically, the X particles would decay into detectable neutrons, or a pair of hidden particles called Y and Φ (the Greek letter phi). The anti-X particles would decay into antineutrons, or pairs of anti-Y and anti-Φ particles. But the X's would be more likely to decay into neutrons, while the anti-X's would be more likely to produce hidden anti-Y's and anti-Φ's.
"When almost all particles with an available antiparticle annihilated one another in the early universe, these discrepancies left a chunk of visible matter and a heavier chunk of dark antimatter to form the cosmos," PhysicsWorld's Kate McAlpine wrote.
The researchers suggest that the existence of the anti-Y and anti-Φ particles could be confirmed by their interactions with protons. Such interactions "could be on the boundary of detectability" at facilities such as the Super-Kamiokande underground particle detector in Japan, said UBC's Kris Sigurdson.
This is by no means the only hypothesis that's been offered to explain the nature of dark matter and the roots of the matter-antimatter balance. One of the main experiments at Europe's Large Hadron Collider, LHCb, is designed to study the decay of B-mesons and anti-B-mesons to see if additional data can help unravel the antimatter mystery. The LHC may also identify exotic particles (neutralinos, maybe?) that account for the dark matter.
I asked SLAC particle physicist Helen Quinn, co-author of the book "The Mystery of the Missing Antimatter," to take a quick look at the X particle concept. "It's very speculative," she told me, "and this is one of the things that particle physicists do all the time."
For now, the X factor is merely one of several hypotheses that might or might not explain one or both of the great mysteries. The truth is out there, and one day physicists will figure out which hypothesis serves as the best explanation for dark matter and/or antimatter. In the meantime, Quinn told me, "there's an awful lot of space out there in which to build models."
"Time will tell," she said.
That's a saying that could be applied to lots of the things that come up in physics -- or life in general.
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from:Not Even Wrong
