Posts tagged LHC
Posts tagged LHC
Published 10:23am Wednesday, February 20, 2013
The European Organization for Nuclear Research (often abbreviated as CERN) and its Large Hadron Collider are a colossal use of finances, time and other resources simply to sharpen the pencil that we humans already own and use.
CERN is valid as a directionless hobby and pastime, one that leisurely whiles away the now pointless, make-busy hours of thousands of scientists, physicists and other geeks worldwide and allows numerous egos to wax wearisomely. CERN perpetuates individual and collective freedom of choice and unbridled co-creations, albeit erroneously in the presumptions underlying the current approach of inquiry because such presumptions fail to factor in God the creator who is the underlying unseen process of divine love and life.
No matter how finely one hones down their pencil, it’s still a pencil. You won’t find what is eternal and limitless in any temporal object, not even in super-fleeting, ultra tiny, super accelerated subatomic particles created through the expenditure of massive amounts of money and electrical energy.
Building bigger toys in the physical world shall always result in a pallid and unsuccessful attempt to find unseen divine principles. Divine love transformed into physical manifestations in this particular physical plane of existence can never be captured or discovered by mere mechanical contraptions nor by their size or might. It’s that simple.
The scientists at CERN are having fun. That’s good, but they will ultimately accomplish no meaningful or useful purpose.
This is a joke, right?
Particle physics explores the structure of matter by studying the behaviour of its most fundamental constituents. Despite the remarkable success of our theories, there remains much that is fundamental but unexplained. One of our most pressing questions concerns the origin of mass. Our favoured theoretical explanation for the existence of mass also predicts the existence of a particle that has never been seen—the Higgs boson. In this review, we survey our knowledge of the Higgs boson and explain why, if the theory is correct, we should expect to make our first observation of the elusive Higgs in the next few years, when a major new particle physics facility starts operating. This will be the most powerful particle accelerator in the world. Although searching for the Higgs boson will be challenging in this environment, we hope that our experimental results will allow us to finally understand the origin of mass and extend our knowledge of the Universe yet further.
20:47 17 December 2010 by Kate McAlpine
The Large Hadron Collider has not yet seen any of the microscopic black holes that inspired numerous scare stories in recent years.
Many theorists actually hope the collider, based near Geneva, Switzerland, will create short-lived, miniature black holes. These would not pose a threat to Earth, but they would provide evidence for hypothetical extra dimensions that might lie beyond the 3D world we normally experience.
If these dimensions exist, gravitons, the particles thought to transmit the force of gravity, could leak into them, providing a much-needed explanation for why gravity is much weaker than the other forces.
At the high energies created inside the LHC, though, colliding protons could be affected even by gravitons in the extra dimensions, making gravity strong enough to create fleeting black holes. So far, however, they have not emerged.
Inside the LHC, black holes would produce an excess of high-energy particles at right angles to the proton beam. Yet researchers working on the Compact Muon Solenoid (CMS) detector at the LHC report that they have not seen this signal so far. This rules out the emergence of miniature black holes at energies between 3.5 and 4.5 trillion electron volts or TeV (arxiv.org/abs/1012.3375).
Extra dimensions may yet exist as miniature black holes could still be produced at higher energies, says CMS spokesperson Guido Tonelli. “The search will continue as usual.” But the new result does rule out some variations on the extra dimensions hypothesis. And it means extra dimensions, if they do exist, are harder to detect than some hoped.
“It puts an important constraint that theorists will have to abide by,” says Dmitri Kharzeev of Brookhaven National Laboratory in New York.
12 May 2011 by David Shiga
NEW particles that mimic the long-sought Higgs boson may bamboozle physicists, who could spend years trying to confirm or rule out the possibility of an impostor, a new study warns.
The standard model of particle physics predicts that a particle called the Higgs boson endows many other particles with mass. The Large Hadron Collider (LHC) at CERN near Geneva, Switzerland, was built in part to detect and study it for the first time.
Higgs bosons should be produced in the wreckage of collisions between pairs of protons smashed together at the LHC. While the Higgs will not be detected directly, it should quickly decay into more familiar particles, such as pairs of photons or heavy Z bosons, carriers of the weak nuclear force. The standard model of particle physics predicts what fraction of the occasions the Higgs should decay into each type of particle, so if decay products are seen in those ratios, we might assume we have finally found the Higgs.
But some other undiscovered particle could decay in the same pattern, say Patrick Fox of Fermilab in Batavia, Illinois, and colleagues, in a paper posted online (arxiv.org/abs/1104.5450). “This was a surprisingly easy thing to arrange,” says team member Neal Weiner of New York University, as such mimicry could occur as a result of a quantum phenomenon called mixing. Mixing allows particles to exist as a blend of two different types, and is known to occur between types of quark and between types of neutrino. If there is a new particle that mixes with the Higgs boson, it will pick up some characteristics of the Higgs.
What would make the disguise almost perfect is if the new particle does not feel the forces of the standard model. Then it would have no intrinsic tendency to decay into standard-model particles. Then even a slight Higgs admixture would make the new particle decay in exactly the same ways as the Higgs, with exactly the same decay products. Ian Low of Argonne National Laboratory in DuPage County, Illinois, who was not a member of the team, agrees that mixing could lead to convincing impostors. “Nature might surprise us,” he says.
While such an impostor would at least imply that the Higgs does exist - a triumph in itself - it would not tell physicists about the long-sought particle’s detailed properties. In particular, the mass of the counterfeit could be very different from that of the genuine article.
It could be an exciting discovery in other ways, because not just any new particle could mimic the Higgs. To do so, it would need to have zero spin, like the Higgs boson itself but unlike any other standard-model particle. Such spin-zero particles arise in theories that include new forces beyond those in the standard model. Some physicists think a new force could explain a variety of anomalies seen recently at the Tevatron particle collider at Fermilab.
If a particle with Higgs-like decays is found at the LHC, it could take years to rule out the possibility that it is an impostor. The best prospect to weed it out would come after an LHC upgrade planned for 2014, when higher-energy collisions should reveal whether the new particle interacts with carriers of the weak force - a property expected for the Higgs boson but not for impostors.
First approved event display images from CMS for 7 TeV collisions (Image: CERN)
Update: Successful collision of two 3.5 teraelectronvolt beams was achieved at 11.06 GMT. The CMS experiment has published pictures of the collisions. “It’s a great day to be a particle physicist,” said CERN director general Rolf Heuer. “A lot of people have waited a long time for this moment.”
Richard Fisher, deputy news editor
Imagine firing needles across the Atlantic and getting them to collide halfway. That’s the technical challenge facing engineers at the Large Hadron Collider today as they prepare to smash together proton beams at the highest-ever recorded energies.
The first attempt to achieve collisions at 7 teraelectronvolts - 3.5 TeV in each beam - began this morning. If successful, the machine will have broken its own world record for collision energy, which was set at 2.36 TeV last December.
Achieving collisions at 7 TeV is a milestone, and marks the official start of the LHC physics programme. Experiments around the machine will probe tens of trillions of high-energy collisions over the next 18 to 24 months.
CERN is broadcasting a live webcast of the event, and will be reporting from the various experiments throughout the day, alongside its Twitter updates.
Some of the experiments, such as Atlas and CMS, are also featuring their own live commentary and blogging.
Finally, the more technically minded can also track the status of the LHC in graphical form.
Putting your hand in the Large Hadron Collider
What would happen if I put my hand into the Large Hadron Collider?
17:31 04 May 2011 by David Shiga
Now you see it, now you don’t. Rather like a conjurer’s white rabbit, the elusive Higgs boson may have slipped from sight again.
A recent report hinted at a glimpse of the long-sought particle at a major detector at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland. But a second detector has now checked its own data and found no corroborating sign of the particle.
The Higgs boson is thought to endow other particles with mass, but has yet to be observed. Four physicists associated with the LHC’s ATLAS detector claimed to have found an anomalous “bump” in its data, possibly due to Higgs particles decaying into pairs of photons. An abstract of their study was leaked online in April.
Now physicists working on the LHC’s other main detector, CMS, have come up empty in an initial search for a similar bump in their data, according to a document shown to New Scientist. So ATLAS’s bump may not be due to Higgs particles, after all, but instead down to something mundane, such as an error in the analysis.
The internal CMS document has not been released to the public, so the result is still preliminary, as was the news of the original ATLAS bump, for that matter, which was leaked before it was reviewed or endorsed by the ATLAS collaboration.
Both leaks are a testament to the excitement surrounding the Higgs. With a result this hot on the horizon, expect more fits and starts in the months to come.
11:50 30 April 2009 by Amanda Gefter
At the moment physicists are having enough difficulty just taming antihydrogen, the simplest possible anti-atom. Can we ever expect them to make antihelium, and then organic antimolecules made from anticarbon and a whole anti-periodic table, too?
The problem here is that every anti-atom has to be built one subatomic antiparticle at a time. For example, if you want to make antideuterium - like antihydrogen, but with an added antineutron - you first have to make the antineutron. Antineutrons are neutral, making them impossible to steer in the conventional way with electromagnetic fields, so you just have to make great numbers of them and hope that for every million or so antineutrons you make, one ends up in the right place to make an antideuterium atom. “And for every further antineutron or antiproton you add, you lose another factor of a million,” says Michael Doser, spokesman for CERN’s AEGIS experiment studying the properties of antimatter.
While no one’s cracked that problem yet, one experiment at CERN is making use of a neat short cut to at least make something other than antihydrogen. ASACUSA has created atoms of “antiprotonic helium”, in which one of the electrons orbiting a helium nucleus is replaced by an antiproton. By studying the light spectra emitted by this composite matter-antimatter atom, the electrical and magnetic properties of the antiproton can be measured with great precision - and compared with those of a regular proton.
As for our chances of making anything more complex, Frank Close, a particle physicist at the University of Oxford, is pessimistic, saying it will take a billion years, give or take. “It depends on how long the human race lasts,” he says. It seems that our best bet for spying more exotic elements of the anti-periodic table is to look up at the sky - and hope that somewhere antistars are busy churning them out for us.
Even if physicists could make enough antimatter to build a viable bomb, the cost would be astronomical compared to existing weapons, like this “Daisy Cutter” bomb (Image: US Air Force)
Antimatter was a lethal weapon. Potent, and unstoppable. Once removed from its recharging platform at CERN… A blinding light. The roar of thunder. Spontaneous incineration.
The idea that humanity might one day harness the annihilative power of antimatter for destructive purposes has a ghastly fascination - and it’s a central part of the Angels and Demons plot, in which a bomb containing just a quarter of a gram of antimatter threatens to obliterate the Vatican.
Relax, says Rolf Landua, a physicist at CERN. There’s a very good reason why nothing like that is going to happen any time soon. “If you add up all the antimatter we have made in more than 30 years of antimatter physics here at CERN, and if you were very generous, you might get 10 billionths of a gram,” he says. “Even if that exploded on your fingertip it would be no more dangerous than lighting a match.” Patients undergoing PET scans have natural radioactive atoms in their bloodstreams emitting tens of millions, if not more, positrons to no ill effect.
Even if physicists could make enough antimatter to build a viable bomb, the cost would be astronomical. “A gram might cost a million billion dollars,” says Landua. “That’s probably more than Barack Obama wants to invest right now.” Frank Close, a particle physicist at the University of Oxford, points out the time problem, too. “It would take us 10 billion years to assemble enough anti-stuff to make the bomb Dan Brown talks about,” he says.
If that seems reassuring, unfortunately the same kind of reasoning does for antimatter as a clean, green energy source. “Maybe it would work if there were lumps of antimatter that nature had spent 15 billion years making for us,” says Close. As it is, we would have to make them one anti-atom at a time, which costs far more energy to make it than we would get out of it - about a billion times more, says Landua.
That’s not to say we can’t harness antimatter in new ways. In 2007, physicists David Cassidy and Allen Mills of the University of California, Riverside, made the first molecules comprised of more than one positronium atom. Positronium atoms quickly annihilate into high-energy gamma rays, so pack lots of them together, and it should be possibly to get them annihilating and emitting light in synchrony - creating an enormously high-powered “gamma-ray annihilation laser” that could be used to image objects as small as atomic nuclei, or to set off nuclear fusion in reactors.