Experiments at the world’s biggest atom smasher have yielded tantalising hints that a long-sought sub-atomic particle truly exists, with final proof likely by late 2012, according to physicists.

“We know everything about the Higgs boson except whether it exists,” said Rolf Heuer, director general of the Europ-ean Organisation for Nuclear Research.

“We can settle this Shakespearean question – to be or not to be – by the end of next year,” he told journalists at a webcast press conference at Cern headquarters in Geneva. Researchers at the US Department of Energy’s Fermilab, meanwhile, also reported telltale signs of the elusive particle, heating up a longstanding rivalry between the two high-energy physics laboratories.

Cern and Fermilab have both reduced the range of mass within which the “god particle”, as it is known, might be found to a fairly narrow, low-mass band.

“The search for the Higgs boson is entering its most exciting, final stage,” Stefan Soldner-Rembold, spokesman for one of Fermilab’s two key experiments, said last week in a statement.

Higgs or no Higgs, the stakes are huge either way, and could easily earn a Nobel Prize for the scientists who can take credit for the breakthrough.