New evidence suggests direct decay of Higgs boson into fermions

Scientists have discovered evidence for the first time, which suggests direct decay of Higgs boson into fermions.

Previously, the Higgs particle could only be detected through its decay into bosons.

Professor Vincenzo Chiochia from the University of Zurich's Physics Institute said that they now know that the Higgs particle can decay into both bosons and fermions, which means they can exclude certain theories predicting that the Higgs particle does not couple to fermions.

According to the standard model of particle physics, the interaction strength between the fermions and the Higgs field must be proportional to their mass.

The researchers analyzed the data gathered at the LHC between 2011 and 2012, combining the Higgs decays into bottom quarks and tau leptons, both of which belong to the fermion particle group and the results revealed that an accumulation of these decays comes about at a Higgs particle mass near 125 gigaelectron volts (GeV) and with a significance of 3.8 sigma.

This means that the probability of the background alone fluctuating up by this amount or more is about one in 14,000. In particle physics, a discovery is deemed confirmed from a significance of five sigma.