Explaining the D0 detector
Fermilab is the world's highest energy particle accelerator. We create beams of high energy protons and antiprotons and bring them into collision with each other. These collisions allow us to see what holds protons together and what they are made of; the collisions also pack sufficient energy into a tiny point of space to create entirely new particles.
The collision points are surrounded by arrays of instrumentation called detectors. D0 is a fairly typical high energy physics detector. It measures thirty feet tall and fifty feet long and consists of four major parts.
1. Tracking system
Outside the silicon, D0 has an outer tracker made using scintillating fibers, which produce photons of light when a particle passes through. The whole tracker is immersed in a powerful magnetic field so the particle tracks are curved; from the curvature we can deduce their momentum.
3. Muon System
4. Trigger system
Simulation of the characteristic signature of a Higgs: the
tracks and energy deposits it would make in the D0 detector.
The proton-antiproton collision produced a Higgs particle, which
decayed to two b-quarks (seen in the detector as energy in the
calorimeter, and indicated by the red arrows at 11 and 5 o'clock),
together with a W boson, whose decay products are an electron
(the green track at two o'clock) and a neutrino (inferred from
an imbalance in overall momentum - the blue arrow at twelve
o'clock). This kind of "associated production" of a W together
with the Higgs is much easier to identify than the Higgs alone.
Discovery of the Higgs will require the accumulation
and study of hundreds of events like this one.
|last modified 5/23/2001 email Fermilab|