Not Being Announced Tomorrow: Discovery of the Higgs Boson

Tomorrow, Tuesday 13 December, there will be a couple of seminars at CERN presented by Fabiola Gianotti and Guido Tonelli, speaking respectively for the ATLAS and CMS collaborations at the LHC. They will be updating us on the current status of the search for the Higgs boson. The seminars will be webcast from CERN, and there should be a liveblog on Twitter that you can follow by searching for the #higgsliveblog hashtag (no Twitter account required). The seminars start at 14:00 Geneva time, so that’s 5:00 a.m. Pacific time if I do my calculations correctly. Of course there will be plenty of news coverage immediately thereafter, so don’t feel too bad if you sleep through it. Many places with LHC physicists (including Caltech) are also having their own local seminars. Should be exciting!

If you want to know why it’s exciting, after you’ve read John’s description of life in the trenches and Matt Strassler’s post about the multiple stages of hunting the Higgs and mine about why we need something like it, see even more recent posts by Matt, Jester, and Pauline Gagnon. Reader’s Digest version: not only are we being updated on the status of the search, there are believable rumors that the searches are actually seeing something — hints of a Higgs near 125 GeV, with better than 3-sigma significance from ATLAS and better than 2-sigma significance from CMS. But obviously rumors are no match for what actually happens.

All I’m here to tell you is: you should not expect to hear anyone announcing that we have discovered the Higgs boson. This will, at best, be a hint — “evidence for” something, not “discovery of” that thing. The collaborations realistically can’t claim to have actually discovered the Higgs, even if it’s there — they don’t have enough data. (CERN even issued a press release to drive home the point.) And in the real world, hints are sometimes misleading. That is: the experimenters will give us their absolute best judgment about what they are seeing, but at this stage of the game that judgment is necessarily extremely preliminary. If they say “we have 3.5-sigma evidence, which is quite suggestive,” do not think that they are just being coy and what they really mean is “oh, we know it’s there, we just have to follow the protocols.” The protocols are there for a reason! Mostly, that many 3-sigma findings eventually go away. This is one step on a journey, not the culmination of anything. (For Americans out there: it’s like a bill has been passed by the House, but not yet passed by the Senate, and certainly not signed by the President. Much can go wrong along the way.)

The journey of a thousand miles begins with a single step. It’s possible that tomorrow’s announcement means that we’re nearing the end of the journey, say at the mile-990 marker. But we can’t be sure, and there are no royal roads to particle physics. Patience! The excitement of not knowing for sure is what makes science one of the most compelling human stories.