Signals detected from the Large Hadron Collider were hailed as conclusive proof that the 'God particle' - the Higgs boson - had been found after a quest spanning nearly five decades.
A week after the discovery of a particle, believed to be the elusive particle, scientists at Cornell University have said they are not so sure.
In a paper published this week, Ian Low, Joseph Lykken and Gabe Shaughnessy of Cornell have cast doubt on what exactly was detected within the Hadron Collider.
'The new resonance discovered by the ATLAS and CMS experiments at the CERN
Large Hadron Collider (LHC) could be the long-sought Higgs boson of the Standard Model,' say the scientists.
But the researchers point out that it's far from certain that the particle is the 'standard model Higgs' which scientists have sought for decades to fill in the 'gaps' in the model of physics we currently use to explain the universe.
'We show that current LHC data already strongly disfavor both the dilatonic and non-dilatonic singlet imposters.
'On the other hand, a generic Higgs doublet and a triplet imposter give equally good fits to the measured event rates of the newly observed scalar resonance.'
The researchers advise caution - and say that 'currently the uncertainties in these quantities are too large' to make a definitive statement.
Scientists at CERN are also analysing the data further to see if their discovery corresponds to the 'standard model' Higgs boson - or to something more mysterious.
One of the reasons for the caution at Cern is that while the new particle has so far behaved liked the elusive Higgs boson it is lighter than expected.