With the Large Hadron Collider now shut down for maintenance, the experimental collaborations at CERN are working to extract every bit of juice from the data collected so far, and in particular to find out more about the Higgs boson that was discovered in the 125-GeV mass region. In recent seminars at CERN, the ATLAS and CMS collaborations presented their latest results on the decay of the Higgs into a pair of particles called tau leptons — results that reveal something interesting about the behaviour of the Higgs.
The discovery of the Higgs exploited its coupling to other bosons — the photon, the Z. But tau leptons (heavier relatives of the electron and muon) are fermions. The 4.1-sigma 'evidence' presented by the ATLAS collaboration shows that the Higgs can decay to fermions as well as bosons, and at a rate that is consistent with the expectation in the standard model. The result is confirmed by the CMS collaboration, who report a 4.0-sigma significance for a combined analysis of taus and bottom quarks (also fermions).