Download or read book Molecular Effects in Tritium Beta decay Neutrino mass Measurements written by Laura I. Bodine and published by . This book was released on 2015 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: An understanding of the molecular final state distribution is crucial to extracting a neutrino mass from molecular tritium-based experiments including the upcoming Karlsruhe Tritium Neutrino Mass Experiment. This dissertation studies molecular systematics for the upcoming neutrino mass measurements and discusses the measurement of molecular dissociation as a test of final state distribution calculations.

Download or read book Molecular Effects in the Neutrino Mass Determination from Beta decay of the Tritium Molecule written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular final state energies and transition probabilities have been computed for beta-decay of the tritium molecule. The results are of sufficient accuracy to make a determination of the electron neutrino rest mass with an error not exceeding a few tenths of an electron volt. Effects of approximate models of tritium beta-decay on the neutrino mass determination are discussed. 14 refs., 3 figs., 1 tab.

Download or read book Limit on the Anti Nu sub E Mass in Free Molecular Tritium Beta Decay written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The question of a nonzero neutrino mass has received considerable attention since the claims of Lyubimov et al in 1980 were published which showed evidence for an electron antineutrino mass between 14 and 46 eV, with a best fit value of 35 eV. However, there are still considerable concerns about possible systematic problems in thier experiment. Many of these concerns revolve around the use of a tritiated valine source, in which the energy given up in final state excitations of the molecule following the veta decay of one of the tritium atoms is comparable to the size of the neutrino mass observed. The effect of these final state effects is difficult to calculate in a molecule as complex as valine. In addition, ionization energy loss and backscattering of the betas in traversing the solid source are appreciable and must be very accurately accounted for. These concerns have led us to carry out an experiment using free molecular tritium as the source material. The final state effects have been accurately calculated for the tritium molecule and the uncertainties in these calculations cannot generate a spurious neutrino mass greater than 1 eV. in addition, the energy loss in the source is small because the source consists of tritium only and there is no backscattering.

Download or read book Calculation of Molecular Final States and Their Effect on a Precision Neutrino Mass Experiment written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment to determine the electron neutrino mass is being performed with the precision of a few electron volts by measuring the tritium beta decay energy distribution near the endpoint. At the few electron volt level, a major consideration in the choice of a tritium source is the effect of excited final atomic or molecular states on the beta decay distribution. It is important to choose a source for which the initial and final states can be accurately calculated. Frozen tritium was chosen as the source since the states of molecular tritium and those of the HeT daughter ion have electronic wavefunctions that can be calculated with high accuracy. The effects of final excited states on the neutrino mass determination and the results of these calculations are described.

Download or read book Los Alamos Free Molecular and Atomic Tritium Beta Decay Experiment written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An initial measurement of the tritium beta spectrum spanning an energy range of 16.4 - 18.9 keV has been performed using a free molecular tritium gas source. With the data from this preliminary low statistics measurement (approx. 72 hours of data), we are able to set an upper limit on the electron-antineutrino mass of 36 eV at the 95% confidence level. Measurements with a gaseous source eliminate many of the ambiguities arising from uncertainties associated with solid-source-based measurements. The ultimate neutrino mass sensitivity of our system should be about 10 eV or less. 13 refs., 9 figs.

Download or read book Progress Report on the Los Alamos Tritium Beta Decay Experiment written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements near the endpoint of the tritium beta-decay spectrum using a gaseous molecular tritium source yield an essentially model-independent upper limit of 27 eV on the /ovr .nu.//sub e/ mass at the 95% confidence level. Since demonstrating from this initial measurement the successful operation of a gaseous source based system, most of our effort has been concentrated towards the upgrade and optimization of the experimental apparatus. The emphasis of this work has been to eliminate or further reduce effects that generate systematic errors. Based on realistic projections from our initial measurement, an ultimate sensitivity to neutrino mass of 10 eV is expected. 12 refs., 1 fig.

Download or read book Problems and Progress in Tritium Beta Decay written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been nearly eight years since the group led by Lubimov first saw evidence for a finite neutrino mass in the tritium beta decay spectrum. Their measurement provided a great stimulus to the field; the number of experiments currently underway reflects the significance of their claim. The fact that further data are only now beginning to appear reflects the difficulty of this measurement. As an introduction to related papers in these proceedings, we briefly consider the key elements involved in neutrino-mass measurements using tritium beta decay and list the experiments currently underway in the field. 5 refs., 1 tab.

Download or read book Experiment to Measure the Electron Neutrino Mass Using Frozen Tritium written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We are performing an experiment to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. To make this measurement, we have built a spectrometer with a resolution of 2 eV. Our source is frozen tritium since tritium and the HeT daughter ion have electronic wavefunctions that can be calculated with high accuracy. We describe the experiment and discuss the excited final molecular state calculations.

Download or read book Limit on Anti Nu sub E Mass from Free Molecular Tritium Beta Decay written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The beta spectrum of free molecular tritium has been measured in order to search for a finite electron antineutrino mass. The final-state effects in molecular tritium are accurately known and the data thus yield an essentially model-independent upper limit of 27 eV on the anti .nu./sub e/ mass at the 95% confidence level. This limit is dominated by the statistics obtained in the data sets. Optimization of the experimental apparatus is underway and an ultimate sensitivity of 10 eV is expected. 19 refs., 2 figs., 1 tab.

Download or read book Measurement of the Electron Antineutrino Mass from the Beta Spectrum of Gaseous Tritium written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement has been made of the mass of the electron antineutrino using the beta spectrum from a source of gaseous molecular tritium, and an upper limit of 36 eV/c2 has been set on this mass. This measurement is the first upper limit on neutrino mass that does not rely on assumptions about the atomic configuration after the beta decay, and it has significantly smaller systematic errors associated with it than do previous measurements. 130 refs., 83 figs., 8 tabs.

Download or read book An Assessment of Anti neutrino Mass Determination Via Electrostatic Measurement of Tritium Beta decay written by Philip Andrew Le Bas and published by . This book was released on 1984 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tau Neutrino Component to Tritium Beta Decay written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A framework is given for explaining anomalous results of neutrino mass experiments that measure the high energy electron spectrum of tritium[beta] decay. The experimental results have been fit to a negative neutrino mass square. We show that there is a consistent phenomenological interpretation due to a positive mass tau neutrino component of the[beta] decay spectrum, with strong near threshold final state interactions with the He nucleus. If this enhancement is due to new interactions between low energy tau neutrinos and nuclei, then the tritium 0 decay experiments could be used as detectors for cosmic background tau neutrinos. The model predicts a distinctive spectrum shape that is consistent with a recent high statistics LLNL experiment. A fit to the experiment gives a tau neutrino mass of 23 eV. Tau neutrinos of this mass would dominate the mass of the universe. Requirements for a theoretical model are given, as well as models that realize different aspects of these requirements. While qualitatively successful, the theoretical models have such severe quantitative difficulties that the accuracy of the molecular physics of the T-[sup 3]He ion, assumed in the analysis of the experimental data, is called into question.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Beta Decays and Neutrino written by Tsuneyuki Kotani and published by . This book was released on 1986 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photonic Electronic And Atomic Collisions Proceedings Of The Xxiv International Conference written by Roberto D Rivarola and published by World Scientific. This book was released on 2006-11-29 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains contributions covering a wide range of subjects in the area of photonic, electronic and atomic collisions. These include the collisions of heavy particles and electrons with atoms, molecules and clusters; the coherent control of reaction dynamics using lasers and electromagnetic fields with molecules, clusters and liquids; recent experimental progress in the synthesis of antihydrogen; the interaction of solar winds with cometary atmospheres, and the physical interpretation of reactions in biological systems./a

Download or read book An Assessment of Anti neutrino Mass Determination Via Electrostatic Measurements on Tritium Beta decay written by P. A. Le Bas and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experiment to Measure the Electron Neutrino Mass Using a Cryogenic Tritium Source written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment has been performed to determine the electron neutrino mass with the precision of a few eV by measuring the tritium beta decay energy distribution near the endpoint. Key features of the experiment are a 2 eV resolution electrostatic spectrometer and a high-activity frozen tritium source. It is important that the source have electronic wavefunctions which can be accurately calculated. These calculations have been made for tritium and the HeT daughter ion and allow determination of branching fractions to 0.1% and energy of the excited states to 0.1 eV. The excited final molecular state calculations and the experimental apparatus are discussed. 4 refs., 5 figs.