This week I'm at the Boost 2011 meeting in Princeton. What "boost" means in this context is speed.

Collisions at the Large Hadron Collider have so much energy that even when lots of it has been used up (via Energy=mass times c2) to produce a particle with large mass, the new particle can still have lots of kinetic energy. That is, it can be travelling very fast.

For objects with masses around 100 GeV or more*, such as W and Z bosons, top quarks, and possibly the Higgs boson, this is the first time we've had enough energy for this to be important. The presence of "boosted objects" like this presents some challenges, but also some opportunities, and this meeting is about trying to cope with the challenges and exploit the opportunities.

All the particles I mentioned above decay, often to jets of hadrons, and we have to look inside the jets to see if we can see signs of the top quark, or the Higgs or whatever. One example of a method to do this is described in the paper we discussed in some of the Colliding Particles films. Gavin** and Adam from these films are both here in Princeton too, as is Lily:



Celebrity scientist spotters amongst you may also be interested to see that the paper Brian Cox mentioned here is also name-checked several times in the meeting, including in Jiji Fan's talk today where it looks like the technique is useful for finding supersymmetric gluons (should they happen to exist).

Anyway, the best thing about the meeting is that we have lots of LHC data now. Adam, Lily and Miguel Villaplana showed the first ATLAS data on measuring these jet substructure variables, including lots of the careful calibration which needs to be done for these fancy jets. Miguel actually showed pictures of the first boosted heavy-particle candidates ever seen - two top quarks.

There have been fascinating results shown from CMS too, as well as the Tevatron experiments. (But I am of course biased in favour of the ATLAS ones, sorry.)

Don't get the idea that this is the only, or even the the most exciting, meeting on LHC data going on. There is such a lot happening now all over the world as physicists digest the data and work out how to extract the best information from it. It just happens that this is the meeting I'm most interested in at the moment, which is why I am here, so I thought I would tell you about it.

And on Thursday I have to summarise the experimental results presented in the meeting. So I have to stop writing and start listening again now...

* I am using cheesy particle physicist "natural units" here, in which the speed of light, c=1.

** In fact Gavin has an association with Princeton these days and is one of the meeting organisers.

PS The first "Boost" was at SLAC, and last year it was in Oxford.