Monday, 2 April 2018

Deep Inelastic Scattering Part 1

Hi everyone and Happy Easter

I am pleased to report that I have finished the first part of my review of Deep Inelastic scattering which describes the early experiments at Stanford which led to first real evidence that quarks existed and were not just bookeeping devices to classify elementary particles with.

During the late 1960's experiments at the newly built Stanford Linear Accelerator showed that at high energies the results of measurement of the inelastic scattering of electrons off protons could be interpreted as the electron scattering off point like spin 1/2 particles which Feynman called partons.

Further work showed that these partons could be identified with the quarks of Gell Mann and Zweig also that whilst the spin half partons could account for half of the protons momentum distribution there was evidence of other neutral partons these later came to be identified with the gluons of quantum chromodynamics (QCD) the current theory of the strong interaction;

The notes for those interested are given below as usual I have tried to give full derivations of the main equations. I also enclose my own analysis of the data from the SLAC experiments

However despite the success of the parton model, it wasn't until scattering experiments involving neutrinos took place that the full identification of the partons with the quarks was able to be made. This will be the topic of the next set of notes in this series which hopefully will be completed by Mid Summer

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