[elwin]

A detector is typically a series of concentric cylinders, with the beam pipe, where the collisions occur, running through the center. The inner layers are tracking chambers, which detect the paths of charged particles. This is what produces all the curved lines radiating from the center.

The outer layers are calorimeters, which catch particles and measure their kinetic energy. As you correctly assumed, these produce the bar plots. Often there will be one layer of calorimeters for photons and electrons, and a second for hadrons (protons, mesons, etc.)

This Wikipedia article is a good starting point: https://en.wikipedia.org/wiki/Hermetic_detector

[themodelplumber]

Very helpful, thank you. Do you know if they have the ability to plot the various events of the collision by time, such that the bar plots could be shown appearing one after another as collision events are recorded?

[mng2]

I'm not familiar with the nitty-gritty of the LHC experiments, but in general the various detector subsystems have different response times and rate capabilities. There are certain types of detectors with explicit time granularity (e.g. time of flight) but for most detectors there would be no time structure within a single collision record ("event").

But you could work backwards to make an animation for each event. From a scientific perspective it's not that interesting though.

[ISL]

I'd expected it to be trivial to hunt down some animated gifs, but to no avail.

Here's a movie derived from an actual event that will give you a feel for things: http://www.atlas.ch/multimedia/proton-event.html

CMS, too: https://www.youtube.com/watch?v=poNftWVbwmM

[themodelplumber]

Wow, thank you. That CMS video is awesome! This really gives me more of a foothold on what is going on.