What is the “Higgs Boson”?
The Higgs Boson is a subatomic particle that was envisioned by British theoretical physicist Peter Higgs, along with other scientists, in the 1960s.
His theory suggests the universe is permeated by a “Higgs field”, evidence for the existence of which would be the discovery of the Higgs boson.

It is the influence of this field on fundamental particles of matter that gives them mass.
To date, however, there is no proof that the Higgs boson actually exists.
The search for evidence has employed the minds of the world’s top physicists, and an expanding array of hi-tech research facilities, for decades.
Peter Higgs, now in his late 80s and retired, will reportedly receive a Nobel Prize if his elusive and as-yet hypothetical particle is found.  
Why is finding it so important?
Scientists have a developed a rule book of how elementary particles and forces interact in the universe – a “Standard Model” for particle physics.
This rule book stops short of explaining how matter gets its mass and so the Higgs boson theory is seen as the key missing piece of the puzzle.
The Standard Model would have to be rewritten, or junked altogether, if the Higgs boson was proven to not exist or found to operate in a different way than the theory suggests. 
Resolving this question would hand scientists a powerful new tool they could use to probe the universe’s other big mysteries – such as the nature of dark matter.

Where are scientists looking for proof of the Higgs boson?
The Higgs Boson cannot be easily observed.
Physicists have turned to experiments which involve smashing together beams containing billions of particles, at high speed and within a vacuum, and watching the results.
It is thought some of the new particles created during these collisions may be Higgs bosons, though they rapidly decay into well-understood particles.
This work is continuing in a bid to find conclusive proof.
More powerful particle accelerators have also been built to speed up the search, with the biggest to date being the Large Hadron Collider (LHC) which came online in 2008.
The LHC runs 27km in a circular tunnel, is built 100 metres underground near the Swiss - French border, and accelerates particles to speeds previously not obtainable.

What do we think the Higgs boson does?
One analogy used to explain how the theory of the Higgs field, and its Higgs bosons, operates involves a cocktail party and a popular hostess.
Guests at the party are uniformly distributed across the room, all talking to their nearest neighbours.
The hostess enters the room, and all those nearby are strongly drawn to her and cluster around her. 
As the hostess moves she attracts the guests she comes close to, while the ones she has left return to their even spacing.
Because of the knot of people always clustered around her she acquires a greater mass than normal - that is, she has more momentum for the same speed of movement across the room.
Once moving she is harder to stop, and once stopped she is harder to get moving again because the clustering process has to be restarted.
The guests at the party are Higgs bosons and the hostess is a particle of matter.

Why could the Higgs boson be found soon?
After years of searching, an end appears to be in sight.
In December 2011, the first full year of data arising from particle smashing experiments at the LHC was released.
These results – combined from two major studies ATLAS and CMS - provided tantalising signs of the Higgs boson but fell short of conclusive proof.
The research has continued at the LHC this year, and another major batch of data has been added to the earlier analysis.
The updated result will be made public in Melbourne at the 36th International Conference on High Energy Physics (ICHEP 2012, 4 – 11 July).
It may conclusively point to the Higgs boson or something altogether different. 
A mystery that has withstood almost 50 years of scientific inquiry could soon be solved.

Why was the Higgs boson data released last year not conclusive? 
Physicists are doing everything they can to rule out the likelihood of random chance leading them down the wrong path.
Analysis of the LHC data available in December last year, which pointed to a possible Higgs boson, was deemed to be inconclusive because chance could not be sufficiently ruled out as a factor affecting the result.
The analysis had a “three-sigma” confidence rating  - meaning the result has a 0.13% possibility of being due to chance.
Physicists generally wait for a “five-sigma” confidence rating – 0.000028% possibility of a chance result – before they declare a discovery.
The data set that will be analysed and presented in Melbourne has more than doubled in size since the December 2011 result, so chance is much less likely to be an issue this time around.  
 


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    The ARC Centre of Excellence for Particle Physics at the Terascale (CoEPP) was established in 2011 through the award of an Australian Research Council grant of around $25 million over seven years.
    The Centre is a collaborative research venture between the University of Melbourne, the University of Adelaide, the University of Sydney and Monash University, with the University of Melbourne hosting the head office.