http://www.newsweek.com/lhc-scientists-spot-mystery-particle-so-weird-it-could-threaten-standard-1201377

There was a huge amount of excitement when the Higgs boson was first spotted back in 2012—a discovery that bagged the Nobel Prize for Physics in 2013. The particle completed the so-called standard model, our current best theory of understanding nature at the level of particles.

Now scientists at the Large Hadron Collider (LHC) at CERN think they may have seen another particle, detected as a peak at a certain energy in the data, although the finding is yet to be confirmed. Again there’s a lot of excitement among particle physicists, but this time it is mixed with a sense of anxiety. Unlike the Higgs particle, which confirmed our understanding of physical reality, this new particle seems to threaten it.