Implications Of Neutrinoless Double Beta Decay

Neutrinoless double beta decay is a hypothetical type of radioactive decay in which two neutrons in the nucleus of an atom simultaneously convert into protons, emitting two electrons and no neutrinos. The observation of neutrinoless double beta decay would have significant implications for our understanding of the nature of neutrinos and the properties of matter. It would prove that neutrinos are their own antiparticles (also known as Majorana particles) and that the total lepton number is not conserved. Additionally, it would provide information on the absolute mass scale of neutrinos, which is currently unknown. The observation of neutrinoless double beta decay would also have implications for our understanding of the matter-antimatter imbalance in the universe and the possible existence of physics beyond the standard model . The discovery of radioactivity by Henri Becquerel in 1896 opened a new dimension in the field of nuclear physics. Alpha, beta and gamma rays are the relics of radioactive decays, and their emissions are governed via strong, weak and electromagnetic interactions respectively. The energy spectrum of alpha and gamma decays are discrete in nature due to the emission of a single particle. In 1914, James Chadwick reported the continuous energy spectrum of beta radiation. In order to explain this continuous spectrum, Wolfgang Pauli proposed the emission of a chargeless and massless fermion along with beta particle and called it "neutron" . On 4ᵗʰ December 1930, Pauli wrote a letter to nuclear physicsts who were going to meet a few days later in Tiibingen, Germany, "Dear Radioactive Ladies and Gentlemen, As the bearer of these lines, to whom I graciously ask you to listen, ...... I have hit upon a desperate remedy to save the "exchange theorem" of statistics and the law of conservation of energy. Namely, the possibility that in the nuclei there could exist electrically neutral particles, which I will call neutrons, that have spin and obey the exclusion principle and that further di er from light quanta in that they do not tra el with the elocity o light. he mass o the neutrons should be of the same order of magnitude as the electron mass and in any e ent not larger than 0.01 proton mass. - he continuous beta spectrum would then make sense with the assumption that in beta decay, in addition to the electron, a neutron is emitted such that the sum o the energies of neutron and electron is constant...

In the last 20 years the disciplines of particle physics, astrophysics, nuclear physics and cosmology have grown together in an unprecedented way. A brilliant example is nuclear double beta decay, an extremely rare radioactive decay mode, which is one of the most exciting and important fields of research in particle physics at present and the flagship of non-accelerator particle physics. While already discussed in the 1930s, only in the 1980s was it understood that neutrinoless double beta decay can yield information on the Majorana mass of the neutrino, which has an impact on the structure of space-time. Today, double beta decay is indispensable for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix. The potential of double beta decay has also been extended such that it is now one of the most promising tools for probing beyond-the-standard-model particle physics, and gives access to energy scales beyond the potential of future accelerators. This book presents the breathtaking manner in which achievements in particle physics have been made from a nuclear physics process. Consisting of a 150-page highly factual overview of the field of double beta decay and a 1200-page collection of the most important original articles, the book outlines the development of double beta decay research theoretical and experimental from its humble beginnings until its most recent achievements, with its revolutionary consequences for the theory of particle physics. It further presents an outlook on the exciting future of the field.

In the last 20 years the disciplines of particle physics, astrophysics, nuclear physics and cosmology have grown together in an unprecedented way. A brilliant example is nuclear double beta decay, an extremely rare radioactive decay mode, which is one of the most exciting and important fields of research in particle physics at present and the flagship of non-accelerator particle physics.While already discussed in the 1930s, only in the 1980s was it understood that neutrinoless double beta decay can yield information on the Majorana mass of the neutrino, which has an impact on the structure of space-time. Today, double beta decay is indispensable for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix. The potential of double beta decay has also been extended such that it is now one of the most promising tools for probing beyond-the-standard-model particle physics, and gives access to energy scales beyond the potential of future accelerators.This book presents the breathtaking manner in which achievements in particle physics have been made from a nuclear physics process. Consisting of a 150-page highly factual overview of the field of double beta decay and a 1200-page collection of the most important original articles, the book outlines the development of double beta decay research — theoretical and experimental — from its humble beginnings until its most recent achievements, with its revolutionary consequences for the theory of particle physics. It further presents an outlook on the exciting future of the field.

Many new neutrinoless double beta decay experiments are planned all over the world. This book reviews this and other related experiments, and the theoretical aspects of the neutrinoless double beta decay and its consequences are summarized.

The search for neutrinoless double beta decay is one of the highest priority areas in particle physics today; it could provide insights to the nature of neutrino masses (currently not explained by the Standard Model) as well as how the universe survived its early stages. One promising experimental approach involves the use of large volumes of isotope-loaded liquid scintillator, but new techniques for background identification and suppression must be developed in order to reach the required sensitivity levels and clearly distinguish the signal. The results from this thesis constitute a significant advance in this area, laying the groundwork for several highly effective and novel approaches based on a detailed evaluation of state-of-the-art detector characteristics. This well written thesis includes a particularly clear and comprehensive description of the theoretical motivations as well as impressively demonstrating the effective use of diverse statistical techniques. The professionally constructed signal extraction framework contains clever algorithmic solutions to efficient error propagation in multi-dimensional space. In general, the techniques developed in this work will have a notable impact on the field.

This important book presents the proceedings of the conference ?Neutrinos and Implications for Physics Beyond the Standard Model?, put on by the Yang Institute for Theoretical Physics, State University of New York at Stony Brook.The observation of neutrino masses and lepton mixing constitutes the first confirmed evidence for physics beyond the Standard Model. This evidence includes the measured deficiency of charged current reactions induced by solar neutrinos and the anomalous zenith angle distribution of atmospheric neutrinos. A profound question now facing theorists is: What do these observations imply for new physics? At the conference, members of the major experiments gave an update on current experimental evidence from solar and atmospheric neutrino data for neutrino oscillations, and status reports from KamLAND and MiniBooNE. Leading theorists also reported on neutrinoless double beta decay, high energy neutrino scattering and precision electroweak data, theoretical models for neutrino masses and lepton mixing, and constraints from neutrino data, etc. Since neutrino physics is at present one of the most exciting areas of particle physics, this volume should be of interest to a wide variety of students and researchers in physics.

Nuclear double beta decay is - together with proton decay - one of the most promising tools for probing beyond-the-standard-model physics on beyond-accelerator energy scales. It is already probing the TeV scale, on which new physics should manifest itself according to theoretical expectations. Only in the early 1980s was it known that double beta decay yields information on the Majorana mass of the exchanged neutrino. At present, the sharpest bound for the electron neutrino arises from this process. It is only in the last 10 years that the much more far-reaching potential of double beta decay has been discovered. Today, the potential of double beta decay includes a broad range of topics that are equally relevant to particle physics & astrophysics, such as masses of heavy neutrinos, the sneutrino, SUSY models, compositeness, leptoquarks & right-handed W bosons. This invaluable book outlines the development of double beta research from its beginnings until its most recent achievements, & also presents the outlook for its highly exciting future. Readership: Particle physicists, nuclear physicists & astrophysicists.

Nuclear double beta decay is one of the most promising tools for probing beyond-the-standard-model physics on beyond-accelerator energy scales. It is already now probing the TeV scale, on which new physics should manifest itself according to theoretical expectations. Only in the early 1980s was it known that double beta decay yields information on the Majorana mass of the exchanged neutrino. At present, the sharpest bound for the electron neutrino mass arises from this process. It is only in the last 10 years that the much more far-reaching potential of double beta decay has been discovered. Today, the potential of double beta decay includes a broad range of topics that are equally relevant to particle physics and astrophysics, such as masses of heavy neutrinos, of sneutrinos, as SUSY models, compositeness, leptoquarks, left-right symmetric models, and tests of Lorentz symmetry and equivalence principle in the neutrino sector. Double beta decay has become indispensable nowadays for solving the problem of the neutrino mass spectrum and the structure of the neutrino mass matrix — together with present and future solar and atmospheric neutrino oscillation experiments. Some future double beta experiments (like GENIUS) will be capable to be simultaneously neutrino observatories for double beta decay and low-energy solar neutrinos, and observatories for cold dark matter of ultimate sensitivity.This invaluable book outlines the development of double beta research from its beginnings until its most recent achievements, and also presents the outlook for its highly exciting future.