Progress in Particle and Nuclear Physics, Volume 26 covers the significant advances in understanding the fundamentals of particle and nuclear physics. This volume is divided into four chapters, and begins with a brief overview of the various possible ideas beyond the standard model, the problem they address and their experimental tests. The next chapter deals with the basic physics of neutrino mass based on from a gauge theoretic point of view. This chapter considers the various extensions of the standard electroweak theory, along with their implications for neutrino physics. The discussion then shifts to the principles of slow neutrons and their fundamental interactions, as well as some slow neutron experiments. The final chapter surveys the role of strangeness in the context of dense hadronic matter, including strangeness as a probe of the dynamics of relativistic heavy ion collisions and its importance in astrophysics. This book will prove useful to physicists and allied scientists.