Elementary Particle Physics

Determining the nature of matter’s smallest constituents, and the interactions among them, is the subject of a branch of fundamental physics called “The Physics of Elementary Particles” – the subject of this book. During the last decades this field has gone through a phase transition. It culminated in the formulation of a new theoretical scheme, known as “The Standard Model”, which brought profound changes in our ways of thinking and understanding nature’s fundamental forces. Its agreement with experiment is impressive, to the extent that we should no longer talk about “The Standard Model” but instead “The Standard Theory”. This new vision is based on geometry; the interactions are required to satisfy a certain geometrical principle. In the physicists’ jargon this principle is called “gauge invariance”; in mathematics it is a concept of differential geometry. It is the purpose of this book to present and explain this modern viewpoint to a readership of well motivated undergraduate students. We propose to guide the reader to the more advanced concepts of gauge symmetry, quantum field theory and the phenomenon of spontaneous symmetry breaking through concrete physical examples. The presentation of the techniques required for particle physics is self-contained, and the mathematics is kept at the absolutely necessary level. The reader is invited to join the glorious parade of the theoretical advances and experimental discoveries of the last decades which established our current view. Our ambition is to make this fascinating subject accessible to undergraduate students and, hopefully, to motivate them to study it further.