Finding the Higgs is the primary aim of the £6bn ($10bn) Large Hadron Collider (LHC) experiment near Geneva.
But recent results from the LHC's US rival suggest physicists could be hunting five particles, not one.
The idea of multiple Higgs bosons is supported by results gathered by the DZero experiment at the Tevatron particle accelerator, operated by Fermilab in Illinois, US.
Researchers working on the experiment observed collisions of protons and anti-protons in the Tevatron.
The collisions produced pairs of matter particles slightly more often than they yielded anti-matter particles.
Physicists had already seen such differences — known as "CP violation", but these effects were small compared to those seen by the DZero experiment.
The DZero results showed much more significant "asymmetry" of matter and anti-matter — beyond what could be explained by the Standard Model.
Bogdan Dobrescu, Adam Martin and Patrick J Fox from Fermilab say this large asymmetry effect can be accounted for by the existence of multiple Higgs bosons.
They say the data points to five Higgs bosons with similar masses but different electric charges.