In the early 1970s, after a slow start, and lots of hurdles, Quantum Field
Theory emerged as the superior doctrine for understanding the interactions
between relativistic sub-atomic particles. After the conditions for a
relativistic field theoretical model to be renormalizable were established,
there were two other developments that quickly accelerated acceptance of this
approach: first the Brout-Englert-Higgs mechanism, and then asymptotic freedom.
Together, these gave us a complete understanding of the perturbative sector of
the theory, enough to give us a detailed picture of what is now usually called
the Standard Model. Crucial for this understanding were the strong indications
and encouragements provided by numerous experimental findings. Subsequently,
non-perturbative features of the quantum field theories were addressed, and the
first proposals for completely unified quantum field theories were launched.
Since the use of continuous symmetries of all sorts, together with other topics
of advanced mathematics, were recognised to be of crucial importance, many new
predictions were pointed out, such as the Higgs particle, supersymmetry and
baryon number violation. There are still many challenges ahead.Comment: 25 pages in total. A contribution to: The Standard Theory up to the
Higgs discovery - 60 years of CERN - L. Maiani and G. Rolandi, ed