CERN Officials May Have Witnessed ‘God Particle’

The Higgs boson is a hypothetical elementary particle predicted by the Standard Model (SM) of particle physics. It belongs to a class of particles known as bosons, characterized by an integer value of their spin quantum number. The Higgs field is a quantum field with a non-zero value that fills all of space, and explains why fundamental particles such as quarks and electrons have mass. The Higgs boson is an excitation of the Higgs field above its ground state.

One possible signature of a Higgs boson from a simulated proton-proton collision. It decays almost immediately into two jets of hadrons and two electrons, visible as lines.

The existence of the Higgs boson is predicted by the Standard Model to explain how spontaneous breaking of electroweak symmetry (the Higgs mechanism) takes place in nature, which in turn explains why other elementary particles have mass. Its discovery would further validate the Standard Model as essentially correct, as it is the only elementary particle predicted by the Standard Model that has not yet been observed in particle physics experiments. The Standard Model completely fixes the properties of the Higgs boson, except for its mass. It is expected to have no spin and no electric or color charge, and it interacts with other particles through weak interaction and Yukawa interactions. Alternative sources of the Higgs mechanism that do not need the Higgs boson are also possible and would be considered if the existence of the Higgs boson were ruled out. They are known as Higgsless models.

Experiments to determine whether the Higgs boson exists are currently being performed using the Large Hadron Collider (LHC) at CERN, and were performed at Fermilab's Tevatron until its closure in late 2011. Mathematical consistency of the Standard Model requires that any mechanism capable of generating the masses of elementary particles become visible at energies above 1.4 TeV; therefore, the LHC (designed to collide two 7-TeV proton beams) is expected to be able to answer the question of whether or not the Higgs boson actually exists. In December 2011, Fabiola Gianotti and Guido Tonelli, spokespersons of the two main experiments at the LHC (ATLAS and CMS) both reported independently that their data hints at a possibility the Higgs may exist with a mass around 125 GeV/c2 (about 133 proton masses, on the order of 10−25 kg). They also reported that the original range under investigation has been narrowed down considerably and that a mass outside approximately 115–130 GeV/c2 is almost ruled out. No conclusive answer yet exists, although it is expected that the LHC will provide sufficient data by the end of 2012 for a definite answer.

"Discovery or exclusion of the Higgs particle, as predicted by the Standard Model, is getting ever closer," CERN Director for Research and Scientific Computing, Sergio Bertolucci, said in a statement. "Both occurrences will be great news for physics, the former allowing us to start the detailed study of the Higgs particle, the latter being the first proof of the incompleteness of the Standard Model, requiring new phenomena to be happening within the reach of the LHC."

"We’re taking our first steps in this new physics landscape," added CMS experiment spokesman Guido Tonelli, "and it is great to see how fast we are producing new results. I am confident that soon there will be only a few regions left where the Higgs boson, as postulated by the Standard Model, might still be hiding."

Source: redOrbit (http://s.tt/160nr)