Quark Model and Beyond: The Eternal Quest

Our universe consists of elementary particles, which interact through four fundamental forces of nature. All the knowledges of science and technology are founded in our knowledge of these phenomena. Along with the quest for fundamental building blocks of matter, the unification of four fundamental forces and origin of our universe, are two unfinished agenda of the 21st century physics. The outstanding issue related to quark dynamics is the problem of quark confinement and its analytical demonstration from the first principle of Quantum Chromodynamics (QCD). At present we consider six quarks and six leptons as the fundamental particles, and we have no idea whether the successive stage of elementariness of matter will continue up to infinity or stop at some particular stage, viz., 10??? cm size as advocated in string theories. This book is an attempt to follow this great intellectual adventure – the quest for the basic building blocks of matter and the laws that govern these entities. The book is roughly divided into the following parts: Foundation of particle physics before the emergence of quark hypothesis; Quark model of hadrons, Concept of color quantum number: its applications and experimental verifications; Parton picture and Quantum chromodynamics (QCD); success and limitations; World of leptons and neutrinos and other elementary particles: Higgs bosons and gauge bosons: experimental considerations; Speculations about the substructures of quarks and leptons and beyond quark physics; Appendices: (I-a) Natural Units and Conversion Factor, (I-b) Development of Cosmic Rays Physics, (I-c) Development of Quantum Field Theory, (I-d) Chronology of the Birth of Particle Physics; (II) Biographical Notes of Some Scientists; (III) Bibliography. The book should be useful to Post Graduate physics students in Indian universities and Post Graduate Colleges, as well as to research scholars and science teachers.