Tag Archives: Large Hadron Collider

‘God Particle’ Discovered – Higgs Boson

After 8000 scientists worked for two decades, spending around 10 billion dollars, the missing link in the origin of the universe may have been found. The world is celebrating what could be this century’s biggest scientific discovery -‘God Particle’. We take a close look at why is this historic, what does it mean and a very significant Indian connect to it.

Why the Collider Matters: In Search of the ‘God Particle’

The ATLAS particle detector at the European Organization for Nuclear Research (CERN) outside Geneva is 150 feet long, 82 feet high, weighs 7,000 tons and contains enough cable and wiring to wrap around Earth’s equator seven times. It’s a mammoth machine, designed for the delightful purpose of detecting particles so tiny you can fit hundreds of billions of them into a beam narrower than a human hair.

ATLAS occupies just one small corner of the strange and wonderful world that is the Large Hadron Collider (LHC) — the circular 14-mile underground particle accelerator that promises scientists untold insights into the mysteries of the cosmos. More than 25 years in the planning, with a price tag of around $10 billion, the LHC officially — finally — began smashing protons together on March 30. The goal: to answer the most fundamental questions about how the universe works. (See photos of the large hadron particle collider.)

The first and most important order of business is to prove (or disprove) the existence of a single particle known as the Higgs boson — a speck so precious that it has come to be called “The God Particle,” a reference to the theory that Higgs gives mass to all matter in the cosmos.

The significance of the God Particle is as old as time itself: scientists believe that at the moment of the Big Bang, when the universe was born, there existed a moment of incandescent beauty — of perfect symmetry — in which all things and all forces were in absolute agreement. The universe’s four forces — the weak force, strong force, electromagnetism and gravity — had yet to differentiate, and the tiny particles that carried those forces had yet to emerge as separate entities. As the explosion cooled and its contents scattered, complexity engulfed the universe, splitting its symmetry asunder — a cosmic parallel to Adam and Eve.

The goal of modern theoretical physics is to reveal the universe’s lost elegance. A major breakthrough in that effort came in 1964, when Peter Higgs, a shy British scientist in Edinburgh, introduced a theory that could explain how particles that carry two of the four forces — those that carry the electromagnetic force, and those that the carry weak force — came to have different masses as the universe cooled (in the moment after the Big Bang, of course, nothing had mass, existing instead in a sort of naked, ethereal beauty). Extrapolating from Higgs’ theory, scientists were able to explain how all particles get their mass — which would explain, in turn, how everything in the universe, from scientists at CERN to the grand Jura mountains that surround them, comes to have weight. (Read “Did a Time-Traveling Bird Sabotage the Collider?”)

It works like this. Across the post–Big Bang universe, collections of Higgs bosons make up a pervasive Higgs field — which is theoretically where particles get mass. Moving particles through a Higgs field is like pulling a weightless pearl necklace through a jar of honey, except imagine that the honey is everywhere, and the interaction is continuous. Some particles, such as photons, which are weightless particles of light, are able to cut through the sticky Higgs field without picking up mass. Other particles get bogged down, accumulating mass and becoming very heavy. Which is to say that even though the universe appears to be asymmetrical in this way, it actually is not — the Higgs field doesn’t destroy nature’s symmetry; it just hides it.

The way to find the Higgs boson is to create an environment that mimics the moment post-Big Bang. The powerful LHC runs at up to 7 trillion electron volts (TEV) and sends particles through temperatures colder than deep space at velocities approaching the speed of light. (The second most powerful particle accelerator, at Fermilab in Illinois, runs at 1 TEV.) The added juice allows scientists to get closer to the high energy that existed after the big bang. And high energies are needed because the Higgs is thought to be quite heavy. (In Einstein’s famous equation E=MC2, C represents the speed of light, which is constant; so in order to find high-mass particles, or M, you need high energies, E.) It’s possible, of course, that even at such high energies the Higgs boson will not be found. It may not exist.

But if it exists, the Higgs would help plug a hole in the so-called Standard Model — the far-reaching set of equations that incorporates all that is known about the interaction of subatomic particles and is the closest thing physicists have to a testable “theory of everything.” But many theoreticians feel that even if the Higgs boson exists, the Standard Model is unsatisfactory; for instance, it is unable to explain the presence of gravity, or the existence of something called “dark matter,” which prevents spiral galaxies like our own Milky Way from falling apart. Even the mighty Higgs cannot explain those mysteries — though through telescopes and observation, we know they exist.

Given the problems with the Standard Model, some physicists have come up with elaborate alternatives to explain the workings of the cosmos, including the existence of multiple, alternate dimensions, or hidden “supersymmetric partners” to all the universe’s particles. To them, failure to find the Higgs — or finding the Higgs among an ensemble of strange and new particles — would be welcome, since it would suggest that more ambitious theories are needed. (See the top 10 scientific discoveries of 2009.)

Out on the cusp of human knowledge, particle physics can seem very esoteric indeed. But the LHC’s findings may have implications that go beyond pure science. CERN, a pan-European project dedicated to peaceful nuclear research, was founded in the late 1940s as a sort of atonement for the legacies of Hiroshima, Nagasaki, and two wars during which Europeans slaughtered one another by the millions — many of CERN’s elder scientists vividly remember the instability, randomness and despair that characterized that era.

If scientists at CERN are able to locate the Higgs particle in the early years of this new century, it would shore up the basic scientific tenet that what exists at the very foundations of our universe is beauty and unity. It’s something to continue to strive for, at least.

Big Bang experiment by CERN explained

Imagine a car crash. Two vehicles, way over the speed limit. Smash into each other. Glass, metal and plastic pieces fly out. That’s what the big bang experiment is. Only those cars, are now the size of atoms. But is that all?

Gravity, is what makes our world go round. If it moves such huge planets, it must be very powerful, right? But actually, it’s much weaker, than even the electricity that powers our bulbs. Nobody knows why. Yet.

CRACKING BIG BANG: Ninety-six per cent of our world  is made of anti-matter.

The more mass we have, the more gravity we exert. And what gives us all mass? Scientists say it’s called a Higgs Boson particle. And that’s what they are looking for in the Large Hadron Collider.

If they find it, they will have more proof for a weird theory. That gravity is actually very strong. It’s just leaking out through world’s dimensions, that we have never seen. That there are parallel universes, peopled perhaps by our own body doubles, who we will never meet.

There’s more. Ninety-six per cent of our world is made of anti-matter. Dan Brown’s “Da Vinci Code” says anti-matter destroys everything it touches. Yet, we’re all alive. Why? One part of this experiment manufactures and studies anti-matter, in a lab.

And finally, the temperature inside the tunnel, is 100,000 times higher than the heart of the sun.

Atoms here melt into a plasma – it’s neither liquid, nor solid, nor gas. Exactly like they were when the universe was born. How that plasma cooled into our stars and planets, is what scientists want to learn.


Large Hadron Collider Test Successful

A scientist gestures in front of  computer animations of the first successful proton beam collisions  conducted at full power, completed 100 metres underground near Geneva on  Tuesday. The Large Hadron Collider is designed to collide proton beams  at energies not seen since the Big Bang.

Geneva, 30 March 2010. Beams collided at 7 TeV in the LHC at 13:06 CEST, marking the start of the LHC research programme. Particle physicists around the world are looking forward to a potentially rich harvest of new physics as the LHC begins its first long run at an energy three and a half times higher than previously achieved at a particle accelerator.

“It’s a great day to be a particle physicist,” said CERN1 Director General Rolf Heuer. “A lot of people have waited a long time for this moment, but their patience and dedication is starting to pay dividends.”

“With these record-shattering collision energies, the LHC experiments are propelled into a vast region to explore, and the hunt begins for dark matter, new forces, new dimensions and the Higgs boson,” said ATLAS collaboration spokesperson, Fabiola Gianotti. “The fact that the experiments have published papers already on the basis of last year’s data bodes very well for this first physics run.”

“We’ve all been impressed with the way the LHC has performed so far,” said Guido Tonelli, spokesperson of the CMS experiment, “and it’s particularly gratifying to see how well our particle detectors are working while our physics teams worldwide are already analysing data. We’ll address soon some of the major puzzles of modern physics like the origin of mass, the grand unification of forces and the presence of abundant dark matter in the universe. I expect very exciting times in front of us.”

“This is the moment we have been waiting and preparing for”, said ALICE spokesperson Jürgen Schukraft. “We’re very much looking forward to the results from proton collisions, and later this year from lead-ion collisions, to give us new insights into the nature of the strong interaction and the evolution of matter in the early Universe.”

“LHCb is ready for physics,” said the experiment’s spokesperson Andrei Golutvin, “we have a great research programme ahead of us exploring the nature of matter-antimatter asymmetry more profoundly than has ever been done before.”

CERN will run the LHC for 18-24 months with the objective of delivering enough data to the experiments to make significant advances across a wide range of physics channels. As soon as they have “re-discovered” the known Standard Model particles, a necessary precursor to looking for new physics, the LHC experiments will start the systematic search for the Higgs boson. With the amount of data expected, called one inverse femtobarn by physicists, the combined analysis of ATLAS and CMS will be able to explore a wide mass range, and there’s even a chance of discovery if the Higgs has a mass near 160 GeV. If it’s much lighter or very heavy, it will be harder to find in this first LHC run.

For supersymmetry, ATLAS and CMS will each have enough data to double today’s sensitivity to certain new discoveries. Experiments today are sensitive to some supersymmetric particles with masses up to 400 GeV. An inverse femtobarn at the LHC pushes the discovery range up to 800 GeV.

“The LHC has a real chance over the next two years of discovering supersymmetric particles,” explained Heuer, “and possibly giving insights into the composition of about a quarter of the Universe.”

Even at the more exotic end of the LHC’s potential discovery spectrum, this LHC run will extend the current reach by a factor of two. LHC experiments will be sensitive to new massive particles indicating the presence of extra dimensions up to masses of 2 TeV, where today’s reach is around 1 TeV.

“Over 2000 graduate students are eagerly awaiting data from the LHC experiments,” said Heuer. “They’re a privileged bunch, set to produce the first theses at the new high-energy frontier.”

Following this run, the LHC will shutdown for routine maintenance, and to complete the repairs and consolidation work needed to reach the LHC’s design energy of 14 TeV following the incident of 19 September 2008. Traditionally, CERN has operated its accelerators on an annual cycle, running for seven to eight months with a four to five month shutdown each year. Being a cryogenic machine operating at very low temperature, the LHC takes about a month to bring up to room temperature and another month to cool down. A four-month shutdown as part of an annual cycle no longer makes sense for such a machine, so CERN has decided to move to a longer cycle with longer periods of operation accompanied by longer shutdown periods when needed.

“Two years of continuous running is a tall order both for the LHC operators and the experiments, but it will be well worth the effort,” said Heuer. “By starting with a long run and concentrating preparations for 14 TeV collisions into a single shutdown, we’re increasing the overall running time over the next three years, making up for lost time and giving the experiments the chance to make their mark.”