LHC: “Evidence soon emerged however that this particular squib might be of the damp variety…”

After the hype, “somewhat excited” reporters are straining to sound convincing – the Guardian live-blogged the presentation.  And Matt Strassler was at the circus in CERN.

I have been chatting with my colleagues, all particle physicists working at or visiting CERN, and finding out how many say that the evidence presented today convinces them that the Higgs has been found.  So far — Experimentalists — No: 9,  Maybe: 1, and a good one; will explain shortly.  Yes: 1 (Tomaso Dorigo, of Quantum Diaries, is the unique individual so far, and I disagree with his assumptions and his conclusions.).  Theorists — No: 6, Yes: 0.  This is not a scientific poll, just a poll of scientists… but anyone who tells you the community as a [whole] is convinced is either confused or making it up.

The Guardian’s tame particle physicist, Jon Butterworth, being too tired [and busy] to provide analysis, offers a limerick instead.

A physicist saw an enigma

And called to his mum “Flying pig, ma!”

She said “Flying pigs?

Next thing you’ll see the Higgs!”

He said “Nah, not until it’s five sigma!”

In the meantime, here’s a good introduction to the Standard Model of Particle Physics from Cern News – it’s the first in a series of videos.

Of course, there may be further wrinkles ahead…

And Matt Strassler’s been thinking about some possible wrinkles.

Adds  Glen Mark Martin has a useful Higgs Rumour Roundup.

Update  In a subsequent post Matt Strassler is “somewhat more optimistic” than his initial reaction.

Given this,

  • What we saw today is probably compatible with a Standard Model-like Higgs at about 125 GeV.
  • What we saw today is also probably compatible with a large but not extraordinary fluctuation in the backgrounds, perhaps combined with a subtle technical problem in one or another analysis.
  • And the only way to find out which of these two is the truth is to gather a lot more data in 2012.  Period.

And  As the Guardian live-blog noted

Here’s the New Scientist take by Lisa Grossman on this afternoon’s seminars:

The ultra-shy Higgs boson may have finally shown itself at the LHC. Both of the main detectors, Atlas and CMS, have uncovered hints of a lightweight Higgs. If it pans out, the only remaining hole in the standard model would be filled.

Even more exciting, a Higgs of this mass, about 125 gigaelectronvolts, would also blast a path to uncharted terrain. Such a lightweight would need at least one new type of particle to stabilise it. “It’s very exciting,” says CMS spokesman Guido Tonelli. “This could be the first ring in a chain of discoveries.”

Grossman continues:

The Atlas data restricts the Higgs to within 115 and 131GeV; CMS rules out a Higgs heavier than 127GeV.

Most excitingly, Atlas saw a tantalising hint of the Higgs at 126GeV; CMS saw one at 124GeV. It is the first time both experiments have seen a signal at nearly the same mass. “We’re very competitive, but once I see they’re coming with results, I’m happy,” Tonelli says. “Their results are important for us. They’re obtained in a completely independent manner.”

That mass also paves the way for physics beyond the Standard Model. Thanks to subtle quantum mechanical effects, a lightweight Higgs needs a heavier companion particle “acting as a sort of bodyguard”, Tonelli says. Otherwise, the quantum vacuum from which particles appear would be unstable, and the universe would long ago have disintegrated. If the Higgs is lightweight, the fact that we are here today suggests there is at least one extra particle beyond the Standard Model.

If confirmed…

, , , , , , , , ,