an Introduction to Supersymmetry

Among the many branches of physics, one area that stays on the edges of human knowledge is the realm of particle physics. Along with string theory and quantum mechanics, the new particles that are discovered through high energy physics research help to shape our understanding of how the universe works. Particle physics seeks to explain the most basic building blocks of the universe—not the familiar atom, neutron, or proton, but the particles that make up the structure of each.

These particles are known as elementary or fundamental particles, because from what current scientific research tells us, they are the particles that make up every atom that exists in our universe. To know the building blocks of these fundamental particles would require advances in string theory. The familiar electron is itself an elementary particle, but protons and neutrons on the other hand, are made up different types of quarks—one of the earliest discovered of the fundamental particles. The experiments to help scientists find elementary particles involve smashing beams of very fast moving particles (moving at nearly the speed of light) in to one another and monitoring what smaller particles came out of the resulting explosion--the large hadron collider is one of these machines, known as a particle accelerator.
Over the span of the past 40 years, particle physicists have been able to discover 12 fundamental particles and four forces (such as gravity and electromagnetism). The last discovered was the tau neutrino in the year 2000.
Supersymmetry states that the elementary particles we’ve discovered so far have “partner” particles, known as superpartners. If that’s true, there could be a plethora of new elementary particles that have yet to be discovered. But, beyond discovering more particles, it would also mean that the principles present in supersymmetry can be applied to quantum mechanics and string theory in order to further the knowledge in each of the fields.
Unfortunately, due to limitations in current particle accelerators, supersymmetry has yet to be proven—that is, no superpartner of any known elementary particle has been found. In mid-2009, the Large Hadron Collider will be powered on, and used for experimentation for the first time. It is the largest and most expensive machine ever constructed. Those working on the project hope that with new technology in use at the LHC, scientists will be able to discover the particles necessary to finally prove supersymmetry.