Tuesday 13 December 2011

THE GOD PARTICLE.... IS IT REAL???


Scientists find signs of missing 'God particle'


The CMS, or Compact Muon Solenoid. It's one of the two general-purpose experiments at the Large Hadron Collider with which physicists hope to detect the Higgs boson.

If anyone has read the book named Angels and Demons the God Particle can be described as “Leonardo believed his research had the potential to convert millions to a more spiritual life. Last year he categorically proved the existence of an energy force that unites us all. He actually demonstrated that we are all physically connected . . . that the molecules in your body are intertwined with the molecules in mine . . . that there is a single force moving within all of us.”

Or the THE GENESIS from Bible in which the first line speaks that “Let there be light” and there was light. Which means that the matter was created out if nowhere which corrects the theory of THE BIG BANG. In order to prove the existence of  the GOD PARTICLE one must create the miniature form of the BIG BANG using particle accelerators and collide the particle at high speed and observe the “events” that happen afterwards. However we not only get the matter but also its counter-particle which can be called as ANTIMATTER, a highly unstable substance which can create an annihilation when it comes in contact of matter.

So the scientists at the CERN, Geneva claims to have find the signs of missing God Particle. Higgs boson (sometimes nicknamed the "God particle" in popular media) is a hypothetical massive elementary particle that is predicted to exist by the Standard Model (SM) of particle physics. The Higgs boson is an integral part of the theoretical Higgs mechanism. If shown to exist, it would help explain why other particles can have mass. It is the only predicted elementary particle that has not yet been observed in particle physics experiments. Theories that do not need the Higgs boson also exist and would be considered if the existence of the Higgs Boson was ruled out. They are described as Higgsless models.
 
A simulated event, featuring the appearance of the Higgs boson.


Scientists at the CERN physics research centre near Geneva said, however, they had found no conclusive proof of the existence of the particle which, according to prevailing theories of physics, gives everything in the universe its mass.

"Physicists will have uncovered a keystone in the makeup of the Universe...whose influence we see and feel every day of our lives."

The leaders of two experiments, ALTAS and CMS, revealed their findings to a packed seminar at CERN, where they have tried to find traces of the elusive boson by smashing particles together in the Large Hadron Collider at high speed.

On 12 December 2011, the ATLAS collaboration at the LHC found that a Higgs mass in the range from 145 to 206 GeV was excluded at the 95% confidence level. On 13 December 2011, experimental results were announced from the ATLAS and CMS experiments, suggesting that if the Higgs Boson exists, it is probably limited to a range of 115–130 GeV at the 3.6 sigma level (ATLAS) or 117–127 GeV at the 2.6 sigma level (CMS), and indicating possible scope for a 124 GeV (CMS) or 125-126 GeV (ATLAS) Higgs.

The red lines show how the LHC's Atlas experiment registered the arrival of four particles called muons. They could have been the byproducts of a short-lived Higgs boson--or they could have been more humdrum events. CERN's LHC particle accelerator will continue smashing protons into each other to spot the statistical significance that means the Higgs really has been found.


"We observe an excess of events around mass of about 126 GeV," CERN physicist and Atlas leader Fabiola Gianotti said in slides presented today at a CERN seminar to physicists who applauded her results. That equates to about 212 quintillionths of a gram by comparison, a proton is more than 100 times lighter with a mass of 0.938GeV. 

Her small sentence carries big import for physics. That's because the Higgs boson, thought by some to endow other particles with mass, is a key missing ingredient in physicists' understanding of what makes the universe tick. It's predicted by the Standard Model of particle physics, but no one has been able to confirm its existence or nature.
"The Higgs could be the first link in a chain of discovery. This is what we hope," said Guido Tonelli of the Universita degli Studi di Pisa and leader of the CMS project, in a news conference after the seminar. Another year of continued data gathering should be enough to provide a conclusive answer on this particular matter, the physicists said. 

Gianotti called the findings "beautiful results" at the seminar, but stopped well short of declaring victory because there's not enough data for statistical certainty. "It's too early to draw definite conclusions...We believe we have built a solid foundation on the exciting months to come." 

Finding the Higgs boson is essentially a matter of checking for a variety of events--or their absence. The LHC's detectors have been gradually ruling out ranges of possible mass for the Higgs boson. 

The Higgs boson isn't observed directly, but rather is detected by extremely rare side effects of collisions between protons smashing into each other. To increase the likelihood of collisions, the LHC operators have been gradually increasing the beam intensity. 

Gianotti also said the CMS results predict with a 95 percent confidence level that the Higgs boson has a mass between 115.5GeV and 131GeV. 

Another experiment, the Compact Muon Solenoid (CMS), also helped narrow down the possible mass of the Higgs boson. Its results showed with a 95 percent confidence level that the particle can't be between 127GeV and 600GeV, Tonelli said. 

The CMS experiment also found "a modest excess of events" that could be evidence of the Higgs boson between 115GeV and 127GeV, Tonelli said in a presentation at the seminar. "The excess is most compatible with a Standard Model Higgs hypothesis in the vicinity of 124GeV and below, but the statistical significance is not large enough to say anything conclusive." 

One of the big mysteries that physicists hope to plumb with the Higgs is an idea called supersymmetry. The Standard Model predicts a wide range of particles, of which the Higgs is the last to be pinned down. But with supersymmetry, each of the conventional elementary particles in the standard model, including the Higgs, has a companion. If there's only one Higgs boson, it's part of the Standard Model. But with supersymmetry, there have to be at least five Higgs bosons. Supersymmetry would double the number of particles to resolve physics problems in a similar way that the prediction--and later discovery--of antimatter did decades ago. 
If the Higgs boson weighs about 125GeV, it would match many physicists' general expectations--but also carry some importance. That's because it's at the light end of the range of possibilities, and physicists believe a particle that light needs another particle from the sypersymmetry collection to anchor it. 
When it comes to mass, physicists liken the Higgs boson to groupies at a party. Heavy particles interact strongly with Higgs bosons, equivalent to a lot of people swarming a celebrity and making it harder for the famous person to start moving and, once moving, harder to stop. Particles with little mass are those that interact weakly with Higgs bosons, making them more fleet-footed. 
"A heavier particle is nothing more that one than has more interactions with the Higgs particle as it passes through the vacuum," said Lawrence Sulak, chairman of Boston University's physics department. 
If the Higgs boson is precisely measured in the next year, the LHC can be used to look further down the same pathway, Tonelli added, possibly finding supersymmetric particles--"if they are in the energy range of the LHC." 
Such particles would likely be vastly heavier--many thousands, perhaps millions, of GeVs, he said. 
That would be quite a coup: supersymmetric particles are a possible explanation for dark matter, material that in the universe outweighs the ordinary matter of which we're made but that generally interacts with ordinary matter only through gravitational pull. 
To find harder particles, CERN plans an LHC upgrade that will let protons be smashed together at twice today's energy level. "Hopefully we'll explore a large region of masses," Tonelli said. And then, the supersymmetry work can begin in earnest. "A lot of parameters are still open, a lot of SUSY models are still open and are waiting to be excluded or confirmed," he said. 
The LHC is a huge, phenomenally complex instrument built in a circular subterranean tunnel 27 kilometers in circumference. It can accelerate protons fast enough that, when they collide, they reproduce energy levels found only in the earliest moments of the universe after the Big Bang. 
"We have had hints today of what its mass might be and the excitement of scientists is palpable. Whether this is ultimately confirmed or we finally rule out a low mass Higgs boson, we are on the verge of a major change in our understanding of the fundamental nature of matter.It can still happen that it is a fluctuation, but all we see from both experiments is compatible with what we would expect for a Higgs signal to build up," said Buchmueller.

"But we really need the data from next year to be sure of what we're seeing."


Source: Times Of India and news.cnet.com

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