150,000 cloud virtual machines will help solve mysteries of the Universe

CERN data center equipment in Geneva.

CERN

When you're running the world's largest particle accelerator, smashing particles at nearly the speed of light to understand the Universe at its most basic levels, you'd better have a great IT strategy.

That's why CERN, the European Organization for Nuclear Research, opened a new data center and is building a cloud network for scientists conducting experiments using data from the Large Hadron Collider at the Franco-Swiss border.

CERN's pre-existing data center in Geneva, Switzerland, is limited to about 3.5 megawatts of power. "We can't get any more electricity onto the site because the CERN accelerator itself needs about 120 megawatts," Tim Bell, CERN's infrastructure manager, told Ars.

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Does antimatter fall up? Experiment could provide the answer

A portion of the ALPHA experiment, designed to create and trap antihydrogen atoms.

CERN/ALPHA collaboration

How deep does the asymmetry between matter and antimatter go? Each type of particle (electrons, protons, etc.) have antimatter partners: positrons, antiprotons, and so forth. These antiparticles have an opposite electric charge (unless they're neutral), but otherwise behave much like their matter counterparts. But one interesting question remains unanswered: does antimatter possess antigravity, experiencing a repulsive force when matter experiences attraction? And, even if antimatter experiences plain old gravity, does it behave in exactly the same way as matter does?

Researchers from the ALPHA experiment at CERN realized their antihydrogen trap could help answer that question. By releasing antihydrogen atoms—consisting of an antiproton and a positron—they could measure whether the atoms fell up or down. Using data they had already obtained, the ALPHA team determined they didn't yet have enough data to rule out antigravity or strange behavior in antimatter.

That may sound like a weak result, but the experiment was not originally designed to perform this test. The implication is that ALPHA could be deliberately used to answer this question in the future, with mindful experiments designed to test the gravity of antimatter.

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LHC’s new particle looking ever more Higgs-like

Interactions with the Higgs field provide everything but photons and gluons with mass.

Fermi Lab

The teams behind the two general-purpose detectors of the Large Hadron Collider, ATLAS and CMS, tend to go through their results when facing a deadline, usually provided by one of the large physics conferences. Last week, the Moriond conference took place in Italy and, as expected, there were a number of updates on the Higgs based on the full data collected over the past year. So far, Peter Higgs and the others that first added the Higgs mechanism to physics' Standard Model are looking pretty good.

When the LHC teams announced that they'd found a new particle this summer, they were very careful to note a caveat. While it showed up at an energy where you might expect to see a Higgs (125GeV or so), they weren't certain it was a Higgs. With the additional data, the uncertainty is beginning to fall by the wayside. As a variety of releases (here's a couple of examples) this week have indicated, the Higgs particle was predicted to have a spin of 0 and be even parity. Further studies of the 125GeV particle produced in the LHC have indicated that it has both of these.

Meanwhile, the numbers of Higgs like particles detected by different decay pathways (two photons, four leptons, etc.) are all within the range of predictions. The ATLAS detector has posted a number of animations that show how the signal at 125GeV appeared in various decay channels as the data piled up, rising above the background of other Standard Model events. This one, which shows the Higgs-ZZ decay pathway, is especially clear. There were also some hints that the Higgs was decaying into two photons more often than expected, but physicist Matt Strassler notes the additional data has pretty much eliminated that prospect.

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Finding the Higgs? Good news. Finding its mass? Not so good.

A collision in the LHC's CMS detector.

Research.gov

Ohio State's Christopher Hill joked he was showing scenes of an impending i-Product launch, and it was easy to believe him: young people were setting up mats in a hallway, ready to spend the night to secure a space in line for the big reveal. Except the date was July 3 and the location was CERN—where the discovery of the Higgs boson would be announced the next day.

It's clear the LHC worked as intended and has definitively identified a Higgs-like particle. Hill put the chance of the ATLAS detector having registered a statistical fluke at less than 10^-11, and he noted that wasn't even considering the data generated by its partner, the CMS detector. But is it really the one-and-only Higgs and, if so, what does that mean? Hill was part of a panel that discussed those questions at the meeting of the American Association for the Advancement of Science.

As theorist Joe Lykken of Fermilab pointed out, the answers matter. If current results hold up, they indicate the Universe is currently inhabiting what's called a false quantum vacuum. If it were ever to reach the real one, its existing structures (including us), would go away in what Lykken called "fireballs of doom."

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Large Hadron Collider shuts down for two years of upgrades

No, finding the Higgs boson doesn't mean the end of physics. But as of today, no atoms will be smashed at the LHC (the Large Hadron Collider at CERN) for approximately two years. During that time, every piece of hardware around the accelerator's full circumference will get some attention, as will the detectors that track collisions.

The LHC was designed to collide protons with a total energy of 14TeV (Tera-electron Volts), but a catastrophic failure early in its history revealed some of the superconducting connectors within the hardware wasn't up to the task. As a result, the LHC hasn't run collisions at energies above 8TeV. Each of these connectors, which link segments of the pipe that the beam travels within, will be replaced over the next two years. While the machine is shut down, the detectors used to track particles will receive maintenance and upgrades.

We're at the annual meeting of the American Association for the Advancement of Science this week, and there will be updates on the properties of the Higgs, as well as the search for dark matter particles. Hopefully we'll hear more about the work that went on during the physics runs of the past several years.

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New Large Hadron Collider data may thin out theories in particle physics

Photograph by Fermilab

Although the Large Hadron Collider is often viewed as a Higgs discovery machine—a task for which it turned out to be admirably suited—the collider isn't a one-trick pony. Its general purpose detectors, ATLAS and CMS, should be able to spot any other unusual particles out there, while the ALICE detector is specialized for heavy ion collisions. But this week, attention fell on LHCb, the Large Hadron Collider beauty experiment.

Beauty is the alternate name for the bottom quark, which was discovered back in the 1980s and is the second heaviest of the quarks. Bottom quarks are often found in particles, called B mesons, in which they're paired with another quark (or an antimatter equivalent). LHCb is designed specifically to track how these B mesons decay, since their pattern of decays provides a sensitive test of the Standard Model of particle physics. Now, the LHCb team has announced they've spotted a number of rare decays—not one-in-a-billion, but close—and they've found that the rate at which decays occur agrees remarkably well with that predicted by the Standard Model. This in turn puts some limits on alternative theories.

With bottom quarks being 30 years old, you might think there would be little left to learn from them. But the fact is that they were heavy enough that they weren't produced in vast numbers by earlier particle colliders. That means that very rare events involving a bottom quark either weren't detected at all or were detected in such small numbers that it was impossible to say anything about these events with any statistical certainty.

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How student coders helped CERN build iPhone app, speed up simulations

Google Summer of Code participant Eamon Ford built an iPhone app for CERN.

Eamon Ford

Google Summer of Code is one of the best deals out there both for students looking to hone their coding skills and for organizations that need cheap, talented labor. A student who completes an open source coding project gets a cool $5,000, and the projects are important enough that even CERN, the European nuclear research organization that runs the Large Hadron Collider, has participated the last two years. The organization had seven students on board this past summer.

We talked to two of them, one who wrote an iPhone app for CERN while home from school, and another who spent the summer at the nuclear research facility while improving code used to simulate the passage of particles through matter.

Laying the foundation

Eamon Ford, a junior at the University of Chicago, estimates he spent 630 hours working nearly every day over the summer on an iPhone and iPad app that gathers news articles, photos, videos, and other media from CERN and then makes them accessible to the public in an easily navigable user interface. Ford wrote in Objective-C in the Apple's Xcode integrated development environment, and said most of what he did was user interface work, modeled after newsreaders such as the Google Currents app.

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CERN celebrates as Higgs signal reaches significance

A four-lepton decay, a possible sign of the Higgs, seen by the ATLAS detector.

CERN

Today, in two seminars held at CERN, the European center for physics, announced evidence that the elusive Higgs particle has finally been discovered.

Physics' Standard Model describes the fundamental particles that make up all matter, like quarks and electrons, as well as the particles that mediate their interactions through forces like electromagnetism and the weak force. Back in the 1960s, theorists extended the model to incorporate what has become known as the Higgs mechanism, which provides many of the particles with mass. One consequence of the Standard Model's version of the Higgs is that there should be a force-carrying particle, called a boson, associated with the Higgs field.

For decades, physicists have been sifting through the output of colliders like the Tevatron and LEP, looking for an indication that the Higgs was present in the spray of exotic particles they detected. The closest they got was a hint of a signal that didn't rise far enough above the background. Now, in less than two years of operation, the Large Hadron Collider's detectors have found clear evidence of a particle that looks a lot like the Higgs.

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Fast neutrinos, C-P violations, and the shrinking space for the Higgs

It has been a busy week in the world of particle physics, with attention focused on the home of the LHC: CERN. This year, the LHC generated five inverse femtobarns worth of data—nearly half the amount generated during the entire lifetime of the Tevatron—before shutting down the proton program a few weeks ago. From now until its scheduled winter shutdown, the LHC will be doing lead ion collisions to examine the quark-gluon interactions that dominated the Universe immediately after the Big Bang.

In the mean time, analysis of the data has continued, and some significant news has come out this week. A further dissection of last year's data has placed tighter limits on where the Higgs boson, which provides mass to other particles, might be hiding (assuming it exists). Meanwhile, the LHCb detector, which studies particles that contain heavy quarks, has found an anomalous behavior that might hint at physics beyond the Standard Model. And the LHC accelerator chain has sent some more neutrinos to detectors at Italy's Gran Sasso, which has helped them eliminate some potential sources of error in their faster-than-light findings. We'll take a look at each of these in turn.