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Double beta decay: theory

Description: A summary is given of interesting particle physics and nuclear physics issues in the theory of double beta decay. 25 references.
Date: January 1, 1984
Creator: Haxton, W.
Partner: UNT Libraries Government Documents Department
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Theoretical aspects of double beta decay

Description: Considerable effort has been expended recently in theoretical studies of double beta decay. Much of this work has focussed on the constraints this process places on gauge theories of the weak interaction, in general, and on the neutrino mass matrix, in particular. In addition, interesting nuclear structure questions have arisen in studies of double beta decay matrix elements. After briefly reviewing the theory of double beta decay, some of the progress that has been made in these areas is summa… more
Date: January 1, 1984
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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Proposed geological solar neutrino measurement

Description: It may be possible to measure the boron-8 solar neutrino flux, averaged over the past several million years, from the concentration of technetium-98 in molybdenum-rich ore. This geochemical experiment could provide the first test of nonstandard solar models that suggest a relation between the chlorine-37 solar neutrino puzzle and the most recent glacial epoch. The necessary conditions for achieving a meaningful measurement are identified and discussed.
Date: January 1, 1982
Creator: Cowan, G. A. & Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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The Neutrino Process and Neutrino R-Process

Description: Almost all of the 3 {center dot} 10{sup 53} ergs released in a core-collapse supernova is carried off by the neutrinos emitted from the cooling neutron star. These neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions, leading to the spallation of nucleonsa and {alpha}-particles and the production of new daughter nuclei, I will describe rather detailed network calculations that suggest this neutrino process'' is an important nucleosynthesis mechani… more
Date: January 1, 1991
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

The Neutrino Process and Neutrino R-Process

Description: Almost all of the 3 {center_dot} 10{sup 53} ergs released in a core-collapse supernova is carried off by the neutrinos emitted from the cooling neutron star. These neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions, leading to the spallation of nucleonsa and {alpha}-particles and the production of new daughter nuclei, I will describe rather detailed network calculations that suggest this ``neutrino process`` is an important nucleosynthesis mecha… more
Date: December 31, 1991
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Shape coexistence, Lanczos techniques, and large-basis shell-model calculations

Description: Numerical many-body techniques based on the Lanczos algorithm and their applications to nuclear structure problems are discussed. Examples include shape coexistence, inclusive response functions, and weak interaction rates in {sup 16}O; weak-coupling descriptions of the 0+ bands in isotopes of Ge and Se; and the evaluation of the nuclear Green`s functions that arise in two-neutrino {beta}{beta} decay and in nuclear anapole and electric dipole moment calculations.
Date: October 1, 1992
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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Limits on CP nonconserving interactions from electric dipole moments

Description: I discuss bounds on CP-nonconserving (CPNC) and parity-nonconserving (PNC) hadronic interactions that result from measurements of atomic electric dipole moments. In most models of hadronic CPNC, the nuclear edm arises primarily from the polarization of the ground state by the CPNC PNC NN interaction, rather than from the edms of valence nucleons. When the atom is placed in an external field, the nucleus is fully shielded apart from nuclear finite size effects and relativistic corrections arisin… more
Date: September 1, 1994
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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Supernova neutrinos, giant resonances, and nucleosynthesis

Description: Almost all of the 3{center dot}10{sup 53} ergs liberated in a core collapse supernova is radiated as neutrinos by the cooling neutron star. The neutrinos can excite nuclei in the mantle of the star by their neutral and charged current reactions. I argue that the resulting spallation reactions are an important nucleosynthesis mechanism that may be responsible for the galactic abundances of {sup 7}Li, {sup 11}B, {sup 19}F, {sup 138}La, {sup 180}Ta, and approximately a dozen other light nuclei. 18… more
Date: January 1, 1990
Creator: Haxton, W.
Partner: UNT Libraries Government Documents Department
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(Nuclear theory). [Research in nuclear physics]

Description: This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion. (LSP)
Date: January 1, 1990
Creator: Haxton, W.
Partner: UNT Libraries Government Documents Department
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The fractional quantum hall effect and the rotation group

Description: The fractional quantum Hall effect is thought to be the result of correlations between electrons induced by their mutual interactions. This paper explores the consequences of these correlations numerically and analytically. The problem is mapped onto the surface of a sphere, so that the number of states in the first Landau level is finite. The following three sections review this geometry, give the matrix elements of the Coulomb interaction, and compare exact wave functions with the Laughlin/Ha… more
Date: December 31, 1992
Creator: Ginocchio, J. N. & Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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Landau-Zener Treatments of Solar Neutrino Oscillations

Description: The authors present a simple derivation of Landau-Zener formulae for nonadiabatic level crossings for linear and exponential density profiles. The derivation depends on a single assumption that applies somewhat differently to the exponential and linear cases, providing some insight into the relationship between the respective formulae. They note that one exponential Landau-Zener formula in common use is only approximately correct. Comparisons with exact calculations are made.
Date: January 1, 1995
Creator: Bruggen, Marcus; Haxton, W. C. & Qian, Y. Z.
Partner: UNT Libraries Government Documents Department
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Solar neutrinos: theory vs experiment

Description: I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka II collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are reviewed, including possibilities for generating time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX galli… more
Date: January 1, 1991
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Nuclear astrophysics

Description: The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and … more
Date: December 31, 1992
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
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Stellar Neutrinos

Description: Neutrino provide an important diagnostic of behavior deep inside the solar core. They also play a major role in the evolution of red giants. Horizontal branch stars, and core-collapse supernovae. I discuss some of the interesting neutrino physics issues that have arisen in studies of stellar evolution.
Date: September 1, 1992
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Solar neutrinos: theory vs experiment

Description: I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka II collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are reviewed, including possibilities for generating time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX galli… more
Date: December 31, 1991
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Solar neutrino oscillations

Description: The special properties of solar neutrinos that render this flux so uniquely important in searches for neutrino masses and flavor mixing are reviewed. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are explained through analogies with more familiar atomic physics phenomena.
Date: December 31, 1993
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Nuclear astrophysics

Description: The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and … more
Date: January 1, 1992
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Core-collapse supernovae and nucleosynthesis

Description: I discuss some of the physics that governs the collapse and explosion of a massive star, including issues such as lepton number losses in the infall stage and neutrino heating and convection following the core bounce. I review recent work on the neutrino process and the r-process, describing how the nucleosynthesis depends on the explosion mechanism. Some of the interesting possibilities for oscillations of closure mass {nu}{sub {tau}}s are discussed, along with their signatures in terrestrial … more
Date: December 1, 1994
Creator: Haxton, W. C.
Partner: UNT Libraries Government Documents Department
open access

Time-reversal-noninvariant, parity-conserving nuclear interactions

Description: The work that has been done in compound nucleus studies of time-reversal-noninvariant (TRNI), parity-conserving (PC) NN interactions is reviewed. The general form of TRNI PC meson-exchange potentials that can be constrained by such studies is discussed a la Simonius. The competing limits that can be obtained from atomic electric dipole moments produced by weak radiative corrections to long-ranged TRNI PNC interactions are then explored. Both classes of constraints limit the magnitude of typical… more
Date: April 1, 1993
Creator: Haxton, W. C. & Hoering, A.
Partner: UNT Libraries Government Documents Department
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