Beta Decay and CP Violation|
|Beta decay is a type of radioactive process that occurs in the sun. A neutron turns into a proton releasing an electron and a neutrino. Part of this process is a mysterious phenomenon called Charge Parity Violation, or CP Violation.
Let's back up a little. One of the fundamental laws of physics is that symmetry is preserved under every circumstance. If you built a clock backwards it would still function, if we lived in a mirror world, the laws of physics would still pertain. Time, according to physics, should run just as well backwards as forwards. For the layperson, the forward direction of time seems like common sense, but for the physicist it presents a big question. Why does time only travel one direction, when there are no apparent physical restrictions on it going the other way? This is where CP violation comes into play.
The famous physicist Richard Feynman, who was known as a great teacher, described the situation very well:
In weak decays, like beta decay, the particles which carry spin, like the neutrino and the electron, come out with a spin tending to the left. The parity of the charge is violated, and that's CP Violation. So this is completely anomalous, as symmetry is not preserved, and by extrapolation we can question whether in fact there is something special about the direction that time flows, and this would start to explain things about the way the universe looks."
Richard Helmer, in conversation, also described the implications of CP Violation:
(quoted from Richard Feynman's audio series The Feynman Lectures on Physics, "Symmetry and Conservation," (Perseus Books) 1964)
One of the interests in CP violation is that if
it actually happens, it may explain why everything in the universe ever
happened. Because we believe that when the universe began, it began in
a perfectly symmetrical state of matter and anti-matter, but if CP
violation occurs then there is a process by which you can end up with
more of one than the other.