Notes on Meson Decays,

R. F. Streater and J. C. Taylor, Nuclear Physics, Vol. 7, pp 276-280, 1958.

ABSTRACT

We use the method of effective Lagrangians to estimate the decay-rates of several mesons. We assume the V-A model of Fermi interactions. We show that it fits better than the S-T model.

REMARK

To get the radiative decay of the pion, we need to assume that the axial current has non-zero expectation value. This is actually an anomaly, which was not understood until the work of Bell and Jackiw, and of Adler, ten years later.

REMARK

This was my first paper; I did the calculations, and all ideas came from J. C. Taylor. In my first try, my predictions were several orders of magnitude too large. Fortunately this was suspected by my co-author. On checking, I realised that I had omitted the factors of 2 pi in the inverse Fourier transform (raised to the power 12). This rough style was common in particle physics at the time; nobody expected any numerical answers in strong interactions to be anywhere near the correct result, so 2 pi was regarded as being of order 1, and omitted. This paper showed that effective Hamiltonians can give results within a factor two, and sometimes better.