When scientists originally found ol’ higgy, there was a bit of a strange blip that’s still confusing: the particle was decaying into two photons more often than it should.
Now researchers at the Atlas experiment have clarified the findings some, but the result is still puzzling. There are two peaks in the data which seem to indicate two different Bosons at two statistically different masses.
Certain extensions of the Standard Model of particle physics postulate the existence of multiple Higgs bosons, [but] none of them would predict that two Higgs particles would have such similar masses. They also don’t predict why one should preferentially decay into two Z particles (the 123.5 GeV bump comes from decays of the Higgs into Zs), while the other would decay into photons.
It’s certainly weird, but physicists out there are betting — one of them literally — that it’s just a fluke or systemic problem, and it’ll go away with more data. The thing is that it hasn’t so far. We’ll just have to wait until the next scheduled data release in March to find out, or maybe to continue being confused.