Happy Particle Day!

I remember when the Large Hadron Collider was first going online, and there were all sorts of horrible theories about what was going to happen.  People thought the world was going to end.  When it kept breaking, I heard at least one source theorize that the Higgs Boson was traveling back in time to thwart attempts to prove its existence. I'm starting to realize, now, that I never really believed they were going to find it.  I had this weird sense of pessimistic determinism about the whole thing, because up to that point, everything about chemistry and physics that was known, as far as I knew, was known long before I was born.  Newtonian physics had been around since, like, Newton.  Quantum physics had been around at least long enough for Einstein to think it was a load of crap.

Then, when I found out how close we were getting, I thought we were going to just end up ruling it out-- not finding the Higgs so much that it stopped being reasonable to think the Higgs existed.  We'd find out that we were even further behind than we thought we were, that the standard model just isn't accurate.

So, it's kind of a big deal to me that we found the Higgs Boson -- or, a Higgs-like particle.  It turns out that on a very fundamental level of the structure of the universe, we're already right.  We're right, and we've been right since the 1970's.

Reuters has a great article about the discovery, the best one I've read today.  It describes, among other things, the response of theoretical physicist Peter Higgs, 83 years old, at the announcement.

Clearly overwhelmed, his eyes welling up, Higgs told the symposium of fellow researchers: "It is an incredible thing that it has happened in my lifetime." [...]

"It is very satisfying," Higgs told Reuters. "For me personally it's just the confirmation of something I did 48 years ago[.]" [...]

"I had no expectation that I would still be alive when it happened[.]" [...]

"For physics, in one way, it is the end of an era in that it completes the Standard Model[.]"

The Higgs-like particle has been demonstrated to a degree of certainty known as Five Sigma, which means the likelihood that the discovery is a fluke is less than 1 in 3,500,000 (3 and a half million) -- accounting for 99.99997% of the data.

Now, the most interesting stuff is still yet to come -- now that we know (to a certainty beyond reasonable doubt) that the particle is there, does it do everything we need the Higgs to do?  Some of the scientists are saying yes, others are saying maybe.  Oliver Buchmueller, a CERN physicist, told Reuters:

If I were a betting man, I would bet that it is the Higgs. But we can't say that definitely yet. It is very much a smoking duck that walks and quacks like the Higgs. But we now have to open it up and look inside before we can say that it is indeed the Higgs.

LHC might have found the Higgs particle

I don't normally have much reason to care about the 4th of July -- it's a banal, masturbatory celebration of America, that mostly features explosions, drinking, and saccharine patriotism. This year, though, I've got a reason to mark the date:  CERN is holding a press conference on Wednesday, and they might be announcing that they found the Higgs Boson.

The Daily Mail and the Associated Press have both declared that announcing the discovery of the Higgs is definitely what CERN intends to announce at the press conference.  Nature, a substantially more credible scientific publication, reports that physicists have discovered a particle, but it's unclear whether it's the Higgs.  Their article quotes one anonymous physicist, "Without a doubt, we have a discovery."  So, whatever is happening on Wednesday, it's going to be good.

Another anonymous scientist, quoted later in the article, says,

In practice you would have to be monstrously sceptical not to be convinced by what we have now.  But the final decisions on what to say on Wednesday are still being made.

But being very close to certain still doesn't qualify as being certain, and scientists quite rightly tend not to claim they're right until they're sure.

Physicists have maintained that they will not announce the discovery of the Higgs until the signal surpasses 5 sigma, meaning that it has just a 0.00006% chance of being wrong. The ATLAS and CMS experiments are each seeing signals between 4.5 and 5 sigma, just a whisker away from a solid discovery claim.

Even if they're right, though, the fun part, it seems, has not yet arrived:

Physicists will now turn their attention to understanding the new particle. Crucially, they will want to know whether it behaves like a mass-giving Higgs, and more specifically whether it behaves like the Higgs predicted in the standard model. One important task will be to carefully measure the different ways that the particle is produced and decays inside the LHC detectors.