The missing piece of the puzzle: the discovery of the Higgs boson On July 4, 2012 the CMS and ATLAS collaborations at the large hadron collider jointly announced the discovery of a new elementary particle, which resembled the Higgs boson, the last remaining undiscovered piece of the standard model of elementary particles. Both groups claimed to have observed a five-standard-deviation (five sigmas) effect above background, the gold standard for discovery in high-energy physics. In this essay I will briefly discuss the how the CMS collaboration performed the experiment and analyzed the data. I will also show the experimental results.