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As we have already mentioned there are several things we have either seen in particle experiments or by observing our universe, which do not fit with our Standard Model. Of course we want that our theory should be able to explain exactly what we see or measure in nature. This motivates us to construct new theories or extensions to our already existing theories. Many of these new theories predict the existence of new heavy particles. One of these particles you may have heard about already is the Higgs particle, which is needed in order to describe a mechanism that gives mass to all particles of the Standard Model. This particle is not yet found, only predicted by theory.
Another not yet found particle is the so-called Z' boson. This particle is a heavy partner of the Z boson and is also predicted
by many theories beyond the Standard Model.
In most models the decay and production of the Z' boson will be very similar to the decay and production of the ordinary Z boson,
which we have already introduced on the previous pages. This means that we can use exactly the same techniques as you have already
learned in order to look for the Z' boson! We can draw the Feynman diagrams for some Z' decays (so you can compare with the ones for Z).
So the only difference is that the Z' is much, much heavier (at least 10 times) than the ordinary Z and is therefore less probable to produce in the proton-proton-collisions. Since the Z' boson is so heavy we need more energy to produce it, and this is exactly what we have at the LHC. In fact you are now ready to find both the Z and the Z'.