Since the publication of the second edition of this book there have been no advances in the subject of the magnitude of the discovery of the Z and W bosons but there have been developments which justify an updated version of the text. From a wider perspective the links between particle physics and cosmology have become closer in a number of ways, in particular as we see the earliest moments after the Big Bang as the ultimate high energy laboratory for testing grand unification on the one hand and grand unification as an essential element in understanding the origins of our universe on the other. Equally the Dark Matter problem is another area where the symbiotic nature of particle physics and cosmology may make the essential contribution to our understanding. Since the 1987A supernova neutrinos are seen to have yet another aspect to their fascinating characteristics as both fundamental components of matter and tools by which we can learn about the cosmos. Without pretending in any way to offer a text in cosmology I have felt it worthwhile to include in this new edition a chapter dealing with these topics.

At a more detailed level I have updated the text to conform to the new (more logical) particle nomenclature as well as improving the treatment of some topics and correcting a few errors in the earlier version.