Colours of the subatomic and Julich world
Quantum chromodynamics (QCD)
QCD theory is a quantum field theory that describes the strong interaction between quarks and gluons. Quarks are the subatomic particles composing the well known neutrons and protons and they occur in six flavours up, down, strange, charm, top and bottom. The proton for example is a composition of three quarks, 2 up quarks and 1 down quark.
If the story ended here then we would be talking about quantum flavourdynamics. Due to the very small mass of the quarks they should have been constantly moving with speeds close that of light, so how are they bound together? At this point the strong force is introduced which is called strong because it is indeed strong so that it can hold the quarks bounded together and it is the strongest of all four of the fundamental forces. Carrier of this strong force is the gluon and analogous to electric charge, in QCD there is the colour charge. Also instead of having positive and negative charge there are three colours representing it red, green and blue (though colour has nothing to do with the real colours). But again this not entirely true… because there are “more” colours the anti-colours and each gluon carries two colours and that will be anti-red and blue or anti-blue and green etc..
In order to make calculations at the subatomic level there are two options perturbative and non-perturbative methods. Lattice QCD is a non-perturbative method for solving QCD problems, but why we use non-pertubative methods? The reason lies with the highly non-linear nature of strong force and the large coupling constant at low energies which makes it impossible for an analytical or perturbative solution to be found.
Julich is a very beautiful place with tons of places to visit while spending your days here. Even though the night life is not that great, if you are the nature type of person and you like to take the bike and move around then here is where you should be, i will let the pictures talk for me.