Wednesday 4 July 2012


CMS and ATLAS both now have conclusive evidence of a Higgs-like particle with a mass of around $125-127$ GeV; this will be covered all over the internet, so I won't go into details here. I will say that it's a thrilling moment, and that we all eagerly await more data, to elucidate the detailed properties of this particle.

But the main reason for this post is to publicly congratulate everybody involved in this work. There are (at least) two distinct groups of people to highlight:

  • The LHC is an extraordinary machine, and has been performing phenomenally well; this discovery is only possible now because the machine has delivered so much integrated luminosity so quickly. It represents an unparallelled engineering achievement, so congratulations to the team who have worked so hard to get it to this stage.

Tuesday 3 July 2012

Professor Higgs, your boson is ready

As has already been discussed extensively by many bloggers (including Jester, Tommaso, Shaun, and especially Peter Woit), CERN are holding a special seminar and press conference tomorrow morning, to announce the latest results on the hunt for the Higgs boson. It is widely rumoured that the evidence of a $\sim 125$ GeV Higgs from last year has strengthened to the point of being conclusive.

The plausibility of said rumours was only increased by a press release, which came out yesterday, giving the final results from the Higgs search at the Tevatron; the paper itself is available here.

String Phenomenology: Days 4 & 5

Well, my blogging momentum ran out towards the end of last week, but I will wrap up the String Pheno series with some points of note from the last two days.

In a day dominated by F-theory talks (at least in the plenary sessions), I thought the best of the lot was from Eran Palti, who discussed 'ultra-local' model-building in F-theory. The idea is to focus on the neighbourhood of a single point in the compact geometry, where all the important interactions are supported. His main point was that in many string models, we don't actually have enough control to calculate physical coupling constants; often an overall proportionality factor is missing, and simply assumed to be 'of order one' (i.e. of magnitude between about .1 and 10). I think this is a very important point; 'string phenomenology' as it stands is a bit of a misnomer, because as far as I know, nobody has yet been able to do an honest calculation of all quantities like masses and coupling constants in a realistic string model.