The other major lasting development of the 70’s and 80’s was the demonstration that the SU(3)xSU(2)xU(1) gauge theory – the Standard Model – was in fact what underlies all of the physical world. Even after the theory was fully proposed this conclusion was not obvious. There initially seemed to be many phenomena that led people to propose elaborations that tried to explain supposedly anomalous results. One of these areas was in weak decays involving only strongly interacting particles – non-leptonic decays.
My work on non-leptonic matrix elements is an interesting example of how a field makes real progress. My early calculations in this area were done using the quark model. An example is given here . These works started to make the case that these decays could be understood within the Standard Model without new interactions. However, the quark model techniques could only go so far.
The next phase involved chiral symmetry techniques, which are rigorous in certain limits. One well known result here was our prediction of the B parameter for kaon mixing which used chiral SU(3). In the end it appears that SU(3) breaking may be unusually large in this channel, but this relation is nevertheless a benchmark value. I used chiral techniques in the phenomenology of many other weak decays also.
Much later, Gene Golowich and I (along with Vincenzo Cirigliano and Kim Maltman) returned to the subject with a full set of modern tools – chiral symmetry, dispersion relations, the renormalization group and modern data. Here we could provide a really neat calculation of a couple of key matrix elements, by relating them to experimental results on current matrix elements in tau decay and e+e- annihilation. This is one of my favorite calculations. I believe that these results are still stronger than their corresponding lattice calculations.