This Halloween I had a bit of a revelation. Between all the Sarah Palin costumes and dissertations on the physics of ghosts, I realized that the W and Z bosons are brain-eating zombies; a fact which helps to understand why physicists are trying so hard to find the Higgs boson. Let me explain.
First, what are the W and the Z (aside from annoyingly uncreative choices for names)? You’ve probably heard that there are 4 forces in nature: gravity, electromagnetism, the strong force, and weak force. Each of these forces is caused by exchanges of messenger particles. So what binds an electron to a proton — thus forming a hydrogen atom — is a constant stream of photons flying back and forth; hence, the photon is the messenger of the electromagnetic force. Similarly, gravity is transmitted by gravitons, and the strong force by gluons. The weak force is a bit odd. It has 3 messengers which are all slight different from each other: the Z, the W+ and the W-.