Nuclear physicists have announced that that by the end of 2012 they could determine whether a theorised particle called the Higgs boson, which has unleashed a gruelling decades-long hunt, exists or not.

Rolf-Dieter Heuer, director general of the European Organisation for Nuclear Research (CERN), told a press conference at Britain's Royal Society: "I'm pretty confident that towards the end of 2012 we will have an answer to the Shakespeare question for the Higgs boson - to be, or not to be?"

CERN runs the world's biggest particle collider, located on the outskirts of Geneva.

According to reports from AFP and Reuters, one of the first tasks assigned to the giant machine has been to step up the quest for the Higgs to resolve one of physics' great puzzles: why some particles have mass and others have little, or none.

The Higgs - named after British physicist Peter Higgs who mooted its existence in 1964 - is one of the last missing pieces in the so-called Standard Model, a unified theory of all the particles and forces in the Universe.

"By the end of 2012 we will either discover the Standard Model Higgs Boson, if it exists, or we will rule it out," said Fabiola Gianotti, who is the spokesman for CERN's biggest particle-collider lab called Atlas.