Feb 03

CMS Test Beam Data

2009-02-03_0922, originally uploaded by TomLoughran.

Sketched in black is a plot of the total energy absorbed in either the hadron or the electron calorimeter subdetector sections from the CMS Test Beam (2004 data). Underneath the faint black line, in red, is the energy absorbed by the electron calorimeter (Ecal) alone. The close overlap between these plots (from 4 runs of 10K events/run of electrons at a beam energy of 30 GeV–30 billion electron volts) indicates that total energy and Ecal energies were the same, and thus that Hcal energy is effectively zero. Thus, all the energy from the electrons was absorbed in the electron calorimeter–exactly what a calorimeter is meant to do: you can’t know the energy of a particle unless you completely stop it; its energy is related to how difficult it is to stop.)

This is data which high school students can access from the CMS detector, one of two general purpose detectors (along with Altas) at the LHC, the Large Hadron Collider, awaiting start-up at CERN. Here’s a link to the kind of poster which students can create using this data. It won’t be long before data from the fully operational CMS detector is available to students in the same way.