The latest rumour is that both ATLAS and CMS have evidence that the Higgs mass is about 125 GeV/C2 at confidence levels of 3.5σ and 2.5σ respectively. At 3.5σ, the measurement could be the result of a random fluke just 0.1% of the time whereas at 2.5σ the fluke factor is about 1%.
If you are really optimistic, I believe you can add these two results together in quadrature to get an overall result with a significance of 4.3σ.
While these might sound like fantastic odds to you and me, particle physicists normally wait until they have a confidence of 5σ or greater before they call it a “discovery”. Anything over 3σ is described as “evidence”.
…Crease wisely cites past experience as the number-one reason for caution. Indeed he quotes University of Oxford physicist and data-analysis guru Louis Lyons as saying “We have all too often seen interesting effects at the 3σ or 4σ level go away as more data are collected.”
As Crease points out, nearly everyone he spoke to in writing his article “had tales – many well known – of signals that went away, some at 3σ: proton decay, monopoles, the pentaquark, an excess at Fermilab of high-transverse-momentum jets”.
We now return to your regularly scheduled programming.