Recent content by aw7879

It is my understanding that this argument of no flavour changing neutral currents at tree level was used to predict the existence of the charm quark. The rule basically states that there cannot be a change in flavour whilst the charge current is neutral...

HELP! OZI rule Can anyone give me an explanation of the OZI rule in particle physics which is a bit better than "if you can split a feynman diagram in two by cutting gluon lines then it is suppressed"

Can Anyone explain how the existence of more than one generation of quark means that flavour change neutral currents do not occour at tree level? How is a flavour changing neutral current deffined anyway? I understand that it has something to do with Cabbibo suppression

Thank you very much, that makes perfect sense. Can anyone point me in the direction of any interesting diagrams showing precession caused by an elliptical pendulum?

HELP! Does anyone know anything about elliptical motions of Pendulums? I'm carrying out a research project on the Foucault Pendulum, and obviously a major issue with one of these devices is the precession caused by elliptical motion. I don't understand why elliptical motion, once present...