Tag Archives: Large Hadron Collider

CERN scientists claim discovery of new particles


Science is awesome! Where would we be without it? TGO

Refer to story below. Source: Associated Press

BERLIN (AP) — A new kind of subatomic particle called the pentaquark has been detected for the first time, the European Organization for Nuclear Research said Tuesday.

The lab, known by its French acronym CERN, said the findings were made by a team of scientists working on the LHCb experiment, one of the four at its Large Hadron Collider.

The existence of pentaquarks was first proposed in the 1960s by American physicists Murray Gell-Mann and Georg Zweig. Gell-Mann, who received the Nobel Prize in 1969, coined the term “quark” to describe the building blocks that make up hadrons — subatomic particles such as the proton and the neutron.

Until recently, only hadrons with two or three quarks had been found. In recent years, physicists have seen evidence of hadrons made up of four quarks, called tetraquarks.

Previous claims to the detection of pentaquarks, containing four quarks and an anti-quark, have been refuted. But experts said the new results from CERN, which have been submitted to the journal Physical Review Letters, appear credible.

“It is indeed compelling, in part because of the clarity of their experimental data, but also because I can’t find a viable alternative explanation,” said Eric Swanson, a theoretical physicist at the University of Pittsburgh.

Swanson, who wasn’t involved with the LHCb experiment, said proof of the existence of pentaquarks would be a major boost for physics.

“Every particle we’re aware of, except for a few oddballs, is made up of quark and anti-quark, or three quarks. That’s what builds up the mass of the universe, what makes you and me and the Earth and the sun,” he said. “This, if verified, should be the beginning of a whole new form of matter.”

Guy Wilkinson, a spokesman for the LHCb experiment team, said studying pentaquarks may help scientists to better understand “how ordinary matter, the protons and neutrons from which we’re all made, is constituted.”

The discovery would be the second major find at the Large Hadron Collider, which is used by physicists from around the world. The collider was instrumental in the discovery of the Higgs boson, a subatomic particle that had long been theorized but never confirmed until 2013.

The collider is housed in a 27-kilometer (16.8-mile) tunnel beneath the Swiss-French border near Geneva. It was recently given a $150 million upgrade that allows atoms to be smashed together with even greater force, allowing it to recreate conditions similar to those during the earliest moments of the universe.

CERN likened previous attempts to prove the existence of pentaquarks to looking for silhouettes in the dark, “whereas LHCb conducted the search with the lights on, and from all angles.”

Three-decade quest backs physics’ ‘Standard Model’


Meanwhile, religious lunatics, Muslims of course, are beheading people because they belong to the wrong brand of Islam, as well as westerners for being infidels…

The two extremes of mankind’s intellect at work; on the one hand you have science (civilized and rational) and on the other you have religion (barbaric and irrational). Any guess as to which one will be the downfall of man? The answer is clear, and has been for the last 5000 years. TGO

Refer to story below. Source: Associated Press

AFP
A scientist looks at a section of the European Organisation for Nuclear Research (CERN) Large Hadron Collider (LHC) in Meyrin, near Geneva, during maintenance works on July 19, 2013

Paris (AFP) – Scientists on Wednesday said that after a nearly three-decade bid they had detected a telltale change in a sub-atomic particle, further backing a key theory about the Universe.

Researchers at the world’s biggest particle collider said they had observed an extremely rare event — the decay of the neutral B meson into a pair of muons, the heavy cousins of electrons.

The results provide further support for the so-called Standard Model, the conceptual framework for the particles and forces that constitute the cosmos, they said in the journal Nature.

Neutral B mesons are unstable composites of two kinds of particles called quarks, bound by the “strong” force.

Their decay into muons is predicted under the Standard Model. But getting evidence to confirm the prediction has been a puzzler since the mid-1980s.

For one thing, neutral B mesons themselves are produced in extreme conditions — in particle colliders or in cosmic-ray interactions, for instance — which makes them hard or very costly to study.

And the transition into muons only occurs about four times in every billion “decays.”

Rival teams at CERN’s Large Hadron Collider (LHC) — the massive underground lab near Geneva that straddles the Franco-Swiss border — worked separately on detecting the elusive event.

They released individual results in July 2013, but, separately, the data batches fell just short of the demanding threshold of accuracy for claiming a discovery.

Their combined analysis, now published in the benchmark peer-reviewed science journal, “easily exceeds this requirement,” the European Organisation for Nuclear Research (CERN) said in a statement.

The paper said the experiments showed that Standard Model, which dates to the 1970s, had cleared another hurdle but others lay ahead.

“In the course of the past few decades, the Standard Model has passed critical tests derived from experiment, but it does not address some profound questions about the nature of the Universe,” the authors said.

The framework does not, for instance, explain dark matter, the stuff that composes nearly 85 percent of the mass in the cosmos and is currently only detectable through its gravitational effect on visible matter.

The quest to understand dark matter is one of the priorities of the current work programme at the LHC, which began last month after a two-year upgrade.

The collider comprises a ring-shaped tunnel where proton beams are whizzed around in opposite directions at speeds approaching that of light.

At four locations in the tunnel, powerful magnets bend the beams, bringing them together so that some of the protons smash together — a brief, intense collision.

The sub-atomic rubble that results is then analysed to look for novel particles or clues about known ones.

In 2012, the LHC confirmed the Higgs Boson, the long-sought Standard Model particle that confers mass.

It earned the 2013 Nobel physics prize for two of the scientists who back in 1964 had theorised the boson’s existence.

CERN’s revamped particle smasher ready to push physics into unknown


Where would we be as a species if it wasn’t for science? We would still be living in caves and hunting for food with primitive tools, much as our ancestors did tens of thousands of years ago. Yet here we are, trying to unlock the mysteries of the universe. TGO

Refer to story below. Source: Associated Press

AFP

The Globe of Science and Innovation at the European Organisation for Nuclear Research (CERN) in Meyrin, near Geneva, Switzerland, on February 10, 2015
 

Geneva (AFP) – Europe’s physics lab CERN said Thursday it had begun tests in preparation for rebooting the world’s biggest particle collider and trying to uncover new particles that could alter our understanding of the Universe.

“We are really excited, because we are entering a new phase,” CERN director general Rolf Heuer told reporters in Geneva.

CERN’s Large Hadron Collider (LHC) went offline in February 2013 for a massive overhaul after identifying what is believed to be the Higgs boson, the long-sought maker of mass theorised in the 1960s.

The giant lab, housed in a 27-kilometre (17-mile) tunnel straddling the French-Swiss border, flushed out the so-called “God particle” by crashing proton beams at velocities near the speed of light.

Now, after nearly doubling energy levels possible in the collider, CERN scientists have their sights set on finding exotic new particles in a previously-inaccessible realm.

Frederick Bordry, CERN director for accelerators and technology, said that proton beams were injected into the LHC over the weekend, especially to test transfer lines.

“It was a good test,” he said.

CERN now plans to begin rebooting the machine within the next two week, allowing beams containing billions of protons travelling at 99.9 percent the speed of light to shoot through the massive ring-shaped collider.

LHC

By the end of May, the mighty machine should be calibrated to reach energy levels allowing the long-awaited proton collisions — brief but super-intense smashups recorded in four labs dotted around the ring — to begin.

The collider’s previous highest power was 8 TeV reached in 2012, but after the upgrade, it will first reach 13 TeV and can potentially be cranked up to a maximum 14 TeV.

– Cracks in Standard Model? –

Firing up the LHC is not like throwing a light switch, Heuer said, stressing the delicacy of the process and pointing out that the two beams that will be shooting around the loop together will have the power to melt a tonne of copper.

“We don’t want to do that. So we are better off increasing the intensity and the power of the beams step by step,” he said.

Experiments at the collider have been seeking to unlock clues as to how the Universe came into existence by studying fundamental particles, the building blocks of all matter, and the forces that control them.

During its next run, researchers will look for evidence of “new physics”. They will probe ‘supersymmetry’ — a theoretical concept informally dubbed Susy — seek explanations for enigmatic dark matter, and look for signs of extra dimensions.

Ordinary, visible matter comprises only about four percent of the known Universe.

“There is an enormous amount of speculation out there that we could go beyond the standard model,” said Tiziano Camporesi, head of the LHC’s Compact Muon Solenoid (CMS) experiment, referring to the mainstream theory of how our visible Universe is constructed.

“We have to prepare our detectors in order to be ready to also look for the unexpected, so we can see whatever may exceed the standard model as we know it,” he said, insisting that the LHC was “at the frontier of what can be done in our field.”

He acknowledged that it was difficult to say when the unexpected might appear.

“If nature is kind with us, it could be quick, and if less kind, it could take some time,” Camporesi said.

While the timeline remains unclear, Heuer meanwhile said he was sure the LHC had new discoveries in store.

“It is high time to find a crack in the standard model,” he said, pointing out that “there is 95 percent of the universe that is still unknown to us.”

Particle physics: Experiments give shape to Higgs


Interesting stuff… TGO

Refer to story below. Source: Associated Press

AFP

Physicists

Paris (AFP) – Physicists on Sunday said they had learned more about the identity of the Higgs Boson, the elusive particle whose ground-breaking discovery was announced nearly two years ago.

Work at the Large Hadron Collider (LHC) — the particle smasher on the French-Swiss border where the breakthrough was made — has answered long-standing questions about how the Higgs behaves, they said.

The Higgs was theorised in the 1960s as being the sub-atomic particle that gives other particles mass. Without it, matter would not exist.

Decades of work followed to explore the idea until on July 4, 2012, rival teams at the LHC announced they had independently found a particle consistent with the Higgs.

But further work was needed to flesh out this discovery and to see how it fits with the Standard Model, the conceptual framework for explaining visible matter in the Universe.

In a study published in the journal Nature Physics, one of the LHC teams said the boson behaves as predicted, and is not an “imposter that looks like it.”

Analysis of the mountain of data from collisions at the LHC shows the boson decays neatly to a group of sub-particles called fermions, in line with Standard Model theory, the paper said.

“This is an enormous breakthrough,” said Markus Klute of the Massachusetts Institute of Technology (MIT) who led the research at the LHC’s Compact Muon Solenoid (CMS).

“Now we know that particles like electrons get their mass by coupling to the Higgs field, which is really exciting.”

Finding the Higgs was only possible through the building of the LHC, the world’s biggest laboratory, made up of a 27-kilometre (17-mile) ring-shaped tunnel.

An army of physicists from around the world sifted through the rubble left from billions of proton smashups, hunting for a telltale signature from a fleeting particle.

The initial discovery put the Higgs’ mass at between 125 to 126 gigaelectronvolts, a standard unit of measurement at sub-atomic level.

Later analysis of the data from these experiments also found that the boson has no “spin,” and rapidly decays into pairs of photons (particles of light) and so-called W or Z bosons.

“We have now established the main characteristics of this new particle,” said Klute in a press release issued by MIT.

“All of these things are consistent with the Standard Model.”

Experiments at the LHC are currently on hold while the collider goes through an upgrade, although scientists are still trawling through reams of data generated from smashups before the shutdown.

Operations are due to resume in 2015, with a three-year programme that will see scientists use more powerful collisions to explore theorised phenomena such as “super-symmetry” which may explain dark matter, the substance that makes up most of the Universe.

The boson is named after Peter Higgs, a British physicist who co-won the Nobel prize last year with Francois Englert of Belgium.

Other physicists who made big contributions were Robert Brout, also a Belgian, who died in 2011, and a US-British team of Dick Hagen, Gerald Guralnik and Tom Kibble.

Elusive ‘Exotic Hadron’ Particles Confirmed


Interesting stuff… TGO

Refer to story below. Source: LiveScience

LHC

The existence of exotic hadrons — a type of matter that doesn’t fit within the traditional model of particle physics — has now been confirmed, scientists say.

Hadrons are subatomic particles made up of quarks and antiquarks (which have the same mass as their quark counterparts, but opposite charge), which interact via the “strong force” that binds protons together inside the nuclei of atoms.

Researchers working on the Large Hadron Collider beauty (LHCb) collaboration at CERN (the European Organization for Nuclear Research) in Switzerland — where the elusive Higgs boson particle was discovered in 2012 — announced today (April 14) they had confirmed the existence of a new type of hadron, with an unprecedented degree of statistical certainty.

“We’ve confirmed the unambiguous observation of a very exotic state — something that looks like a particle composed of two quarks and two antiquarks,” study co-leader Tomasz Skwarnicki, a high-energy physicist at Syracuse University in New York said in a statement. The discovery “may give us a new way of looking at strong-[force] interaction physics,” he added.

The Standard Model of particle physics allows for two kinds of hadrons. “Baryons” (such as protons) are made up of three quarks, and “mesons” are made up of a quark- antiquark pair. But since the Standard Model was developed, physicists have predicted the existence of other types of hadrons composed of different combinations of quarks and antiquarks, which could arise from the decay of mesons.

In 2007, a team of scientists called the Belle Collaboration that was using a particle accelerator in Japan discovered evidence of an exotic particle called Z(4430), which appeared to be composed of two quarks and two antiquarks. But some scientists thought their analysis was “naïve” and lacked good evidence, Skwarnicki said.

A few years later, a team known as BaBar used a more sophisticated analysis that seemed to explain the data without exotic hadrons.

“BaBar didn’t prove that Belle’s measurements and data interpretations were wrong,” Skwarnicki said. “They just felt that, based on their data, there was no need to postulate existence of this particle.”

So the original team conducted an even more rigorous analysis of the data, and found strong evidence for the particle.

Now, the LHCb team has studied data from more than 25,000 meson decay events selected from data from 180 trillion proton-proton collisions in the Large Hadron Collider, the world’s largest and most powerful particle accelerator. They analyzed the data using both the Belle and BaBar teams’ methods, and confirmed the particle was both real and an exotic hadron.

The results of the experiment are “the clincher” that such particles do exist, and aren’t just some artifact of the data, Skwarnicki said.

His colleague, Sheldon Stone of CERN, also praised the achievement. “It’s great to finally prove the existence of something that we had long thought was out there,” he said.

Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

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