If you are anything like me, you were surprised that the LHC announced a 5-sigma result for the Higgs boson last July. Not because it wasn't there - it clearly was - but because usually physicists are really, really conservative in their claims. While astronomers start every press release with 'may mean life on other planets' and biologists love to invoke missing links ten times a year, experimental physicists play things pretty close to the vest.
But they have gone through all of the 2012 data now and feel a lot more comfortable announcing is as discovered so they have gone from saying it is 'Higgs-like' to Higgs. CMS and ATLAS have compared a number of options for the spin-parity of this particle, and these all prefer no spin and positive parity. This, coupled with the measured interactions of the new particle with other particles, strongly indicates that it is a Higgs boson because a Higgs boson is postulated to have no spin, and in the Standard Model its parity – a measure of how its mirror image behaves – should be positive.
Now the big question is; what kind of Higgs boson is it?
New results indicate that new particle is a Higgs boson - CERN
