The LHCb team tracked how these particles decayed further into either the matter or antimatter version of particles called kaons.

BBC: Antimatter results emerge at LHC - but puzzle abides

Mesons measured by LHCb have already hinted at an answer, and Prof Parkes says that is the next target.

BBC: LHC's D-meson study wraps up antimatter 'flip' story

"This is a nice moment, it's a sort of completeness, " said Chris Parkes of the University of Manchester, spokesman for UK participation in the LHCb experiment.

BBC: LHC's D-meson study wraps up antimatter 'flip' story

But the LHCb team is reporting a difference of about 0.8% - a significant difference that, if true, could herald the first "new physics" to be found at the LHC.

BBC: LHC reveals hints of 'new physics' in particle decays

"If one decays more often to this final state... than the other one, then it shows a fundamental difference between matter and antimatter, " said Chris Parkes of the University of Manchester, spokesperson for the UK contingent of the LHCb collaboration.

BBC: Antimatter results emerge at LHC - but puzzle abides

LHCb, one of the six separate experiments at the Large Hadron Collider, is particularly suited for examining what is called "charge-parity violation" - slight differences in behaviour if a given particle is swapped for its antimatter counterpart (changing its charge) and turned around one of its axes (changing its parity).

BBC: LHC reveals hints of 'new physics' in particle decays