Introduction To The Physics Of Massive And Mixed Neutrinos

For many years neutrino was considered a massless particle. The theory of a two-componentneutrino,whichplayedacrucialroleinthecreationofthetheoryof theweakinteraction,isbasedontheassumptionthattheneutrinomassisequalto zero. We now know that neutrinos have nonzero, small masses. In numerous exp- iments with solar, atmospheric, reactor and accelerator neutrinos a new p- nomenon, neutrino oscillations, was observed. Neutrino oscillations (periodic transitionsbetweendifferent?avorneutrinos? ,? ,? )arepossibleonlyifneutrino e ? ? mass-squareddifferencesaredifferentfromzeroandsmalland?avorneutrinosare “mixed”. The discovery of neutrino oscillations opened a new era in neutrino physics: an era of investigation of neutrino masses, mixing, magnetic moments and other neutrino properties. After the establishment of the Standard Model of the el- troweak interaction at the end of the seventies, the discovery of neutrino masses was the most important discovery in particle physics. Small neutrino masses cannot be explained by the standard Higgs mechanism of mass generation. For their explanation a new mechanism is needed. Thus, small neutrino masses is the ?rst signature in particle physics of a new beyond the Standard Model physics. It took many years of heroic efforts by many physicists to discover n- trino oscillations. After the ?rst period of investigation of neutrino oscillations, manychallengingproblemsremainedunsolved.Oneofthemostimportantisthe problem of the nature of neutrinos with de?nite masses. Are they Dirac n- trinos possessing a conserved lepton number which distinguish neutrinos and antineutrinos or Majorana neutrinos with identical neutrinos and antineutrinos? Many experiments of the next generation and new neutrino facilities are now under preparation and investigation. There is no doubt that exciting results are ahead.

A deeper understanding of neutrinos, with the goal to reveal their nature and exact role within particle physics, is at the frontier of current research. This book reviews the field in a concise fashion and highlights the most pressing issues and areas of strongest topical interest. It provides a clear, self-contained, and logical treatment of the fundamental physics aspects, appropriate for graduate students. Starting with the relevant basics of the SM, neutrinos are introduced, and the quantum mechanical effect of oscillations is explained in detail. A strong focus is then set on the phenomenon of lepton number violation, especially in 0nbb decay, as the crucial probe to understand the nature of neutrinos. The role of neutrinos in astrophysics, expected to be of increasing importance for future research, is then described. Finally, models to explain the neutrino properties are outlined. The central theme of the book is the nature of neutrino masses and the above topics will revolve around this issue.

Since the discovery of neutrino oscillations neutrino physics has become an interesting field of research in physics. They imply that neutrino must have a small mass and that the neutrinos, coupled to the charged leptons, are mixtures of the mass eigenstates, analogous to the flavor mixing of the quarks. The mixing angles for the quarks are small, but for the leptons two of the mixing angles are large. The masses of the three neutrinos must be very small, less than 1 eV, but from the oscillation experiments we only know the mass differences — the absolute masses are still unknown. Also we do not know, if the masses of the neutrinos are Dirac masses, as the masses of the charged leptons and of the quarks, or whether they are Majorana masses.In this volume, an overview of the present state of research in neutrino physics is given by well-known experimentalists and theorists. The contents — originated from talks and discussions at a recent conference addressing some of the most pressing open questions in neutrino physics — range from the oscillation experiments to CP-violation for leptons, to texture zero mass matrices and to the role of neutrinos in astrophysics and cosmology.

The recent groundbreaking discovery of nonzero neutrino masses and oscillations has put the spotlight on massive neutrinos as one of the key windows on physics beyond the standard model as well as into the early universe. This third edition of the invaluable book Massive Neutrinos in Physics and Astrophysics is an introduction to the various issues related to the theory and phenomenology of massive neutrinos for the nonexpert, providing at the same time a complete and up-to-date discussion on the latest results in the field for the active researcher. It is designed not merely to be a guide but also as a self-contained tool for research with all the necessary techniques and logics included. Specially emphasized are the various implications of neutrino discoveries for the nature of new forces. Elementary discussions on topics such as grand unification, left–right symmetry and supersymmetry are presented. The most recent cosmological and astrophysical implications of massive neutrinos are also dealt with. Contents: From Massless to Massive Neutrinos:IntroductionThe Standard Model and the NeutrinoMassive NeutrinosDirac versus Majorana MassesNeutrino OscillationsSolar NeutrinosModels of Neutrino Mass:Neutrino Mass SU(2)L x U(1)Y ModelsNeutrino Mass in Left-Right Symmetric ModelsNeutrino Mass in Grand Unified ModelsNeutrino Mass in Supersymmetric ModelsLarge Neutrino MixingsImplications of Neutrino Mass:Kinematic Tests of Neutrino MassElectromagnetic Properties of NeutrinosDouble Beta DecayRelated ProcessesNeutrino Properties in Material MediaNeutrinos from SupernovaeNeutrino CosmologySterile Neutrinos Readership: Graduate students and researchers in high energy physics and astrophysics. Keywords:Reviews:“Mohapatra and Pal have produced perhaps the most exhaustive and authoritative book on the physics of massive neutrinos with a well-balanced emphasis on both phenomenology and unified theories. A great contribution to an exciting field.”Professor Jogesh Pati University of Maryland “This book is an exciting and inspirational account of the present state and future prospects for studying massive neutrinos. Written by two of the leading theoretical contributors to the subject, the story can be read on many levels: by a student, using the text as an introduction to one of the most promising areas of modern particle physics; by a professor, as an authoritative and clear account of the theory and the experiments; and by an active researcher, as a source of stimulating new insights.”Professor John Bahcall Institute for Advanced Study, USA

The physics of neutrinos--uncharged elementary particles that are key to helping us better understand the nature of our universe--is one of the most exciting frontiers of modern science. This book provides a comprehensive overview of neutrino physics today and explores promising new avenues of inquiry that could lead to future breakthroughs. The Physics of Neutrinos begins with a concise history of the field and a tutorial on the fundamental properties of neutrinos, and goes on to discuss how the three neutrino types interchange identities as they propagate from their sources to detectors. The book shows how studies of neutrinos produced by such phenomena as cosmic rays in the atmosphere and nuclear reactions in the solar interior provide striking evidence that neutrinos have mass, and it traces our astounding progress in deciphering the baffling experimental findings involving neutrinos. The discovery of neutrino mass offers the first indication of a new kind of physics that goes beyond the Standard Model of elementary particles, and this book considers the unanticipated patterns in the masses and mixings of neutrinos in the framework of proposed new theoretical models. The Physics of Neutrinos maps out the ambitious future facilities and experiments that will advance our knowledge of neutrinos, and explains why the way forward in solving the outstanding questions in neutrino science will require the collective efforts of particle physics, nuclear physics, astrophysics, and cosmology.

Neutrinos play a decisive part in nuclear and elementary particle physics, as well as in astrophysics and cosmology. Some of their most basic properties, such as their mass and charge conjugation symmetry, are largely unknown. This book focuses on what we know and may hope to know about the mass of the neutrino and its particle-antiparticle symmetry. Topics include neutrino mixing, neutrino decay, neutrino oscillations, double beta decay, solar neutrinos, supernova neutrinos and related issues. The authors stress the physical concepts, and discuss both theoretical and experimental techniques. This updated second edition differs from the first in that it contains an expanded coverage of experimental results and theoretical advances. Since publication of the first edition, many issues that were at that time unresolved, such as tritium beta decay and reactor neutrino oscillations, have been clarified and are discussed here. Also included is an expanded coverage of solar and supernova neutrinos. This book deals with one of the most intriguing issues in modern physics, and will be of value to researchers, graduate students and advanced undergraduates specializing in experimental and theoretical particle physics and nuclear physics.

Small neutrino masses are the first signs of new physics beyond the Standard Model of particle physics. Since the first edition of this textbook appeared in 2010, the Nobel Prize has been awarded "for the discovery of neutrino oscillations, which shows that neutrinos have mass". The measurement of the small neutrino mixing angle $\theta_{13}$ in 2012, launched the precision stage of the investigation of neutrino oscillations. This measurement now allows such fundamental problems as the three-neutrino mass spectrum - is it normal or inverted? – and the $CP$ violation in the lepton sector to be tackled. In order to understand the origin of small neutrino masses, it remains crucial to reveal the nature of neutrinos with definite masses: are they Dirac neutrinos possessing a conserved lepton number, which distinguishes neutrinos and antineutrinos, or are they Majorana neutrinos with identical neutrinos and antineutrinos? Experiments searching for the neutrinoless double beta decay are presently under way to answer this fundamental question. The second edition of this book comprehensively discusses all these important recent developments. Based on numerous lectures given by the author, a pioneer of modern neutrino physics (recipient of the Bruno Pontecorvo Prize 2002), at different institutions and schools, it offers a gentle yet detailed introduction to the physics of massive and mixed neutrinos that prepares graduate students and young researchers entering the field for the exciting years ahead in neutrino physics.

Summarizes the theoretical, phenomenological, and astrophysical aspects relevant to research on the possibility of a massive neutrino. Designed as an introduction to the subject for readers familiar with field theory, group theory, and the basic concepts in particle physics; and as a quick reference for old hands in the field. Annotation copyrighted by Book News, Inc., Portland, OR