First results from PETRA provide new aspects of the basic structure of matter

First experimental results from the new large positron-electron storage ring PETRA have been obtained during the first half of 1979. To describe these results a short summary of the present understanding of the basic structure of matter is given. The most recent results are compatible with the existence of gluons, the field quanta of the nuclear force. The possible existence of a quark-lepton-symmetry has led to search for a sixth quark, the t-quark, but no evidence has been seen up to the highest energies of 31.6 GeV.