On 22 June 2012 CERN announced an upcoming seminar covering tentative findings for 2012, and shortly afterwards rumours began to spread in the media that this would include a major announcement, but it was unclear whether this would be a stronger signal or a formal discovery. Speculation escalated to a "fevered" pitch when reports emerged that Peter Higgs, who proposed the particle, was to be attending the seminar. On 4 July 2012 CMS announced the discovery of a previously unknown boson with mass 125.3 ± 0.6 GeV/ c and ATLAS of a boson with mass 126.5 GeV/ c. Using the combined analysis of two decay modes (known as 'channels'), both experiments reached a local significance of 5 sigma — or less than a 1 in one million chance of a statistical fluctuation being that strong. When additional channels were taken into account, the CMS significance was 4.9 sigma.