Matters are made of quarks and leptons. There are three families of them, each containing two quarks and two leptons. Ordinary matters are made of leptons and quarks of Family I. Quarks also come in three colours. The interaction of lepton and quarks are described by the Standard Theory, which is described by the gauge group SU(3) x SU(2) x U(1). It consists of the electromagnetic interaction mediated by the photon, the charged weak interaction mediated by the W+ bosons, the neutral weak interaction mediated by the Z boson and the strong interaction mediated byt he eight gluons.The charged weak interaction mixes quarks from different families. It is this mixing that gives rise to CP violation phenomena. [Author's abstract].

Part of the Physics in a New Era series of assessments of the various branches of the field, Elementary-Particle Physics reviews progress in the field over the past 10 years and recommends actions needed to address the key questions that remain unanswered. It explains in simple terms the present picture of how matter is constructed. As physicists have probed ever deeper into the structure of matter, they have begun to explore one of the most fundamental questions that one can ask about the universe: What gives matter its mass? A new international accelerator to be built at the European laboratory CERN will begin to explore some of the mechanisms proposed to give matter its heft. The committee recommends full U.S. participation in this project as well as various other experiments and studies to be carried out now and in the longer term.

From 5 to 15 August 1984, a group of 79 physicists from 61 laboratories in 26 countries met in Erice for the 22nd Course of the International School of Subnuclear Physics. The countries represented were Austria, Belgium, Brazil, Bulgaria, Canada, People's Republic of China, Denmark, the Federal Republic of Germany, France, Greece, Hungary, Iran, Israel, Italy, Japan, Korea, Malaysia, Mexico, the Netherlands, Pakistan, Poland, Sweden, Switzerland, Turkey, the United Kingdom, the United States of America. The School was sponsored by the Italian Ministry of Public Education (MPI), the Italian Ministry of Scientific and Technologi cal Research (MRST), the Regional Sicilian Government (ERS), and the Weizmann Institute of Science. The programme of the School was devoted to a review of the most significant results in theoretical and experimental research work on the interactions between what we believe today are the point like constituents of the world: quarks and leptons. It should however not be forgotten that many problems are still to be understood: especially in the forefront of the correla tion between quarks and leptons. This game started in 1966 with the proposal for "leptonic quarks" and went on with "preons" and "rishons" just to quote the most famous attempts to unify these two worlds.

Understanding the quark structure of matter has been one of the most important advances in contemporary physics. It has unravelled a new and deeper level of structure in matter, and physics at that level reveals a unity and aesthetic simplicity never before attained. All forces emerge from a unique invariance principle and each of the basic interactions results from a specific symmetry property. Quarks interact among themselves through their ?colour?, as now accurately described by quantum chromodynamics.This volume brings together eight major review articles by Maurice Jacob, a physicist at the forefront of research on the quark structure of matter. He has, in particular, been involved with two research topics in this field. The first is the study of hadronic jets, which one actually sees instead of quarks, because of the opacity of the vacuum to colour. The second is the search for quark matter, a new form of matter believed to exist at high temperatures, when the vacuum should become transparent to colour.The papers in this volume provide a comprehensive review of these phenomenological studies on the quark structure of matter, and also a fasinating insight into the pace of recent progress in these areas. The book comes complete with an original introduction by the author, and also contains a pedagogical review on what is a most engrossing and rewarding field of research in physics.

In recent years, the study of weak interaction and its relationship with the other fundamnetal interactions of nature has progressed rapidly. Weak interactions of leptons and quarks provides an up-to-date account of this continuing research. The Introduction discusses early models and historical developments in the understanding of the weak force. The authors then give a clear presentation of the modern theoretical basis of weak interactions, going on to discuss recent advances in the field. These include development of the eletroweak gauge theory, and the discovery of neutral currents and of a host of new particles. There is also a chapter devoted entirely to neutrino astrophysics. Its straightforward style and its emphasis on experimental results will make this book an excellent source for students (problem sets are included at the end of each chapter) and experimentalists in the field. Physicists whose speciality lies outside the study of elementary particle physics will also find it useful.

A Scientific Introduction to Subatomic particles, Alien Intelligence, and Human Space Exploration (For the Cosmically Curious): There are many fundamental questions about the universe that have intrigued scientists, philosophers, and ordinary people for centuries. Here are a few of them: What is the universe made of? This is one of the most basic questions about the universe. Scientists have identified a number of different types of matter and energy, including atoms, subatomic particles, dark matter, and dark energy, but there is still much we don't know. How did the universe begin? The origin of the universe is a subject of intense study and debate. The prevailing theory is the Big Bang, which suggests that the universe began as a singularity and has been expanding ever since. What is the ultimate fate of the universe? Will it keep on expanding indefinitely or will it ultimately come to an end? Some theories suggest that the universe may end in a "big rip" or a "big crunch," while others suggest that it will continue to expand indefinitely. What is the nature of space and time? These are fundamental concepts that are still not fully understood. Some theories suggest that space and time are intertwined and that they can be distorted by the presence of matter and energy. Are there other universes beyond our own? Some theories suggest that our universe may be just one of many in a "multiverse." Although this theory is yet hypothetical, it is a fascinating concept that could have significant ramifications for our comprehension of the cosmos. These are just a few of the many fundamental questions about the universe that scientists and philosophers continue to explore. "Understanding the Universe: Quarks, Leptons and the Big Bang" is a comprehensive exploration of the fundamental principles that govern the universe we live in. From the tiniest particles to the grandest structures in the cosmos, this book takes readers on a journey of discovery through the mysteries of modern physics and cosmology. Starting with an introduction to the basic building blocks of matter, the book delves into the strange world of quarks and leptons, exploring their properties and interactions. It then examines the forces that govern the behavior of matter, including the strong and weak nuclear forces, electromagnetism, and gravity. The book also covers the history of the universe, from its origins in the Big Bang to the present day, and discusses the evolution of stars and galaxies. Readers will gain a deep understanding of the structure of the universe, its expansion, and the mysterious dark matter and dark energy that make up the vast majority of its mass. Filled with engaging examples, clear explanations, and fascinating insights, "Understanding the Universe: Quarks, Leptons and the Big Bang" is a must-read for anyone interested in the inner workings of the cosmos. Whether you're a student of physics, a science enthusiast, or simply curious about the universe, this book will provide you with a solid foundation for understanding the world around us.

A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never directly observed or found in isolation; they can be found only within hadrons, such as baryons (of which protons and neutrons are examples), and mesons. For this reason, much of what is known about quarks has been drawn from observations of the hadrons themselves. Quarks have various intrinsic properties, including electric charge, mass, color charge and spin. Quarks are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as fundamental forces(electromagnetism, gravitation, strong interaction, and weak interaction), as well as the only known particles whose electric charges are not integer multiples of the elementary charge. There are six types of quarks, known as flavors: up, down, strange, charm, top, and bottom. Up and down quarks have the lowest masses of all quarks. The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state. Because of this, up and down quarks are generally stable and the most common in the universe, whereas strange, charm, bottom, and top quarks can only be produced in high energy collisions (such as those involving cosmic rays and in particle accelerators). For every quark flavor there is a corresponding type of antiparticle, known as an antiquark, that differs from the quark only in that some of its properties have equal magnitude but opposite sign. This book gives a comprehensive overview of the quark.