He is most noted for his co-discovery of the Higgs mechanism (explaining how some but not all elementary particles have mass) and prediction of the Higgs boson (a massive particle central to the Higgs mechanism) with Gerald Guralnik and C. R. Hagen (GHK). As part of Physical Review Letters 50th anniversary celebration, the journal recognized this discovery as one of the milestone papers in PRL history. For this discovery Prof. Kibble was awarded the American Physical Society's 2010 J. J. Sakurai Prize for Theoretical Particle Physics. While widely considered to have authored the most complete of the early papers on the Higgs theory, GHK were controversially not included in the 2013 Nobel Prize in Physics. In 2014, Nobel Laureate Peter Higgs expressed disappointment that Kibble had not been chosen to share the Nobel Prize with François Englert and himself.