ICHEP is over, long live ICHEP

Posted on 26/07/2010 by Jon Butterworth

See also Chapter 3.4 of Smashing Physics.

ICHEP now moves from the parallel to the plenary sessions. Some people leave, some arrive. Some, like me, stay.

l'ATLAS

Top restaurant.

On Friday evening we had concert by a string quartet dressed as the Reservoir Dogs in the beautiful Hotel de Ville de Paris. Debussy’s slow movement was slightly spoiled by the guy behind typing on a phone which made a noise like nylon trousers. But the concert was excellent.

I loved the Saturday session on jet measurements. A jet here is a spray of particles produced by a quark or a gluon in a high energy collision. There were talks from HERA, the Tevatron and the LHC.

The rest of this entry is on the Guardian Science blog.

Share

Posted in Particle Physics, Physics, Science, Travel | Tagged , , , , | Comments Off on ICHEP is over, long live ICHEP

More Bosons and a Geeky Backpack

Posted on 23/07/2010 by Jon Butterworth

See also Chapter 3.4 of Smashing Physics.

Ok, I registered, and now have yet another geeky backpack, a pen, and a map of Paris. Plus a dog-tag with my name and “ICHEP 2010” on so that security don’t throw me out. Excellent. Off to a day of parallel talk sessions.

A very crowded Higgs session at ICHEP (photo: Mike Paterson)

In one room the audience were hearing how well the LHC detectors were working, which is very well indeed. This is a major achievement, not to be taken for granted. They have come into operation much more smoothly than is usual for highly complex particle detectors.

However, I basically knew that already, so I went to another very crowded session where the latest HERA and Tevatron measurements of the W and Z bosons were being shown, along with the very first measurements of these particles from ATLAS and CMS at the LHC.

The rest of this entry is on the Guardian Science blog.

Share

Posted in Particle Physics, Physics, Science, Travel | Tagged , , , | 1 Comment

Heading off to ICHEP

Posted on 22/07/2010 by Jon Butterworth

See also Chapter 3.4 of Smashing Physics.

I’m writing this on the Eurostar at St.Pancras, waiting for it to pull out of the station and take us to Paris, and the International Conference on High Energy Physics (ICHEP).

Of course there are many international conferences on high energy physics, it’s a completely international subject. But there’s only one ICHEP. Well, one every two years, anyway. And this, after many promises and a false start, is the ICHEP where first data from the Large Hadron Collider (LHC) will be presented to the world.

The rest of this post is on the Guardian Science blog.

Share

Posted in Particle Physics, Physics, Physics Stories, Science, Travel | Tagged , , , , , , | Comments Off on Heading off to ICHEP

Quarks, Gluons and Jets

Posted on 18/07/2010 by Jon Butterworth

An updated version of this post is now on The Guardian. See also the glossary section after Chapter 1.5 of Smashing Physics.

Yesterday we (ATLAS) released our first (preliminary) jet cross section measurement.

“Cross section” in this context is basically a probability. If you fire two footballs at each other, they have a bigger cross-sectional area than two snooker balls, so they are more likely to hit each other. A “jet cross section” is a measure of how likely we are to see jets when we fire two protons at each other.

An ATLAS event with two jets.

Jets are what quarks and gluons do when they try to escape. The proton is made up of quarks stuck together by gluons (the name gluon is itself, I guess, an early geekjoke). Most of the fundamental forces get weaker with distance – the Earth’s gravitational pull gets weaker the the further out into space you go, for example. But the strong nuclear force is the other way round.

Continue reading →

Posted in Particle Physics, Physics, Science | Tagged , , , | 6 Comments