Race to find 'God particle'

One of the greatest prizes in modern physics - the confirmation or otherwise of a theoretical sub-atomic particle called the Higgs boson - is back up for grabs.

In a friendly but intense rivalry, European and US scientists have been going head-to-head to find the particle that will either confirm or wreck our concept of the physical universe.

In 2000, scientists at the CERN laboratory in Switzerland came, they believed, within a hair's-breadth of spotting the Higgs before their atom-smasher had to be scrapped to make way for a more powerful machine, due to be finished in 2007.

That threw a vital chance to CERN's rivals at Fermilab's Tevetron particle accelerator in Batavia, Illinois.

But, says the British weekly New Scientist, the Tevatron itself is running into big problems.

It is finding it technically tricky to muster the high-energy beams that smash protons and antiprotons together to see if Higgses tumble out of the rubble, New Scientist reports in next Saturday's issue.

The collider, 20 years old, is also feeling its age, and there are long periods of maintenance and repair between experiments.

A schedule of the Tevatron's activities, handed last week to the US Department of Energy, which provides funding for the collider, says the earliest date for concrete proof for finding or disproving a Higgs at the most-touted energy range will be 2009 at the earliest, the article says.

That is a whole two years after Europe's fancy new Large Electron Positron (LEP) collider, which should be able to generate smashes at awesome energy extremes, is scheduled to come onstream.

'Everyone is disappointed and frustrated,' Fermilab's Judy Jackson told New Scientist.

The boson -- so hard to find that it has been ironically dubbed 'the God particle' -- is named after a Scottish physicist, Peter Higgs.

He puzzled over the so-called Standard Model of physics, a century-old bestiary headed by the atom and which reaches down to progressively tinier and more exotically-named sub-particles such as muons, quarks and stranges.

In the 1960s, researchers figured out how these particles interact, binding together through weak or strong electrical forces. But they were unable to explain why they also had mass.

Higgs hypothesised that the space in between the particles was filled by a heavy, treacly substance.

This substance, he theorised, was populated by mass-giving mediators, now called Higgs bosons.

So if the Higgs is discovered, that would fill the gap in the Standard Model and comfortingly confirm our perception of what the Universe is and how it works.

But if it is proved that the Higgs does not exist, that would be a huge event.

It would open the way for a whole range of alternative theories to replace the Standard Model -- that, for instance, there are overlapping 'parallel' Universes or higher dimensions.

Previous experiments suggest that if the Higgs does exist, it must have a mass of between 114 and 211 gigaelectronvolts (GeV).

CERN's team believed they sniffed the Higgs at 115 GeV, but later discovered they had botched their calculations in the heat of the moment, and that they had mistakenly misinterpreted background noise, as the collider's energy ratcheted up, as scattered Higgses.

Fermilab's date of 2009 for testing for proof of the Higgs is also based on 115 GeV.

If the Higgs is not found at that mass, Europe's LHC should be powerful enough to scan the rest of the possible masses up to 211 GeV to see whether this enigmatic particle exists or not.