Gluon, boson, photon. Names we call things we can't see, taste, touch, feel, or hear that do stuff to our physical reality.
End-on view of one of three WZ events. The collision occured at the center of the detector. A Z boson decayed to two muons (two of the green tracks). A W boson candidate decayed to a muon and a neutrino (a green track and purple arrow opposite to it). Other lower energy charged-particles were produced in the collision and are represented as grey tracks. The straighter the track, the more energetic the particle. The red and blue towers in between the dark circles represent energy deposited in DZero calorimeter by the particles created in the collisions. (Click on image for larger version.)
The W and Z bosons are particles that carry the weak force, one of the four fundamental forces found in nature. According to the Standard Model, the W and Z bosons interact with each other due to their weak charge. At Fermilab, we measure the strength of the interaction of the W boson with the Z boson by identifying and studying collisions in which both are produced at the same time. By counting the number of occurrences and measuring the properties of the WZ events, we can test the strength of the interaction between the bosons.
W and Z particles are very massive. The W boson weights 85 times the mass of a proton. The Z boson is even heavier. Shortly after they are produced, W and Z bosons disintegrate into lighter types of particles and we detect these "decay products" in the DZero detector. The figure shows one of the DZero candidate events with W and Z bosons produced.
Fermilab's proton-antiproton collider, the Tevatron, is the only particle accelerator in the world that ever could produce both a W and a Z boson in the same collision. DZero scoured approximately 14 trillion collisions produced between April 2002 and June 2004 and found three events with both a W and a Z boson in them. We estimate that processes which look like, but aren't WZ production, will provide us three or more such events 3.5% of the time.
With these three candidate we are able to estimate the rate the Tevatron produces WZ events. Also, we set constraints on the strength of the interaction between the W and Z bosons.
http://www.fnal.gov/pub/today/archive_2005/today05-02-10.html