130 research outputs found

    Critical pluralism : a new approach to religious diversity

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    The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on September 27, 2007)Vita.Thesis (Ph. D.) University of Missouri-Columbia 2007.The world's religions provide a wide range of competing religious claims. The problem of religious diversity is that, while many of these claims are inconsistent with one another, they often seem to rest on roughly equal evidence. For this reason, it is not clear which religion, if any, is true. My dissertation examines the various responses to this problem and proposes a unique solution. While some claim that the wide disagreement on religious matters is reason to discard all religious claims as false, I provide an extensive argument in favor of a particularly religious position I call "Critical Pluralism." Critical Pluralism occupies a middle ground between those who claim that all major religions are somehow equally true and those who claim that one religion alone is true. On my view, religious belief systems often provide inadequate yet partially true accounts of a transcendent reality. Many religions approximate the truth to some degree. Some even do so a great deal better than others. Nonetheless, there is not a single religion that exclusively captures the truth.Includes bibliographical reference

    Precision calculation of isospin-symmetry-breaking corrections to T=1/2 mirror decays using multi-reference charge-dependent density functional theory

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    We present systematic study of isospin impurities (αISB\alpha_{\rm ISB}) to the wave functions of T=1/2T=1/2, 11A4711\leq A \leq 47 mirror nuclei and the isospin-symmetry-breaking (ISB) corrections (δISBV\delta_{\rm ISB}^{\rm V}) to their ground state vector β\beta-decays using, for the first time, multi-reference charge-dependent density functional theory (MR-DFT) that includes strong-force-rooted class-III interaction adjusted to correct for the Nolen-Schiffer anomaly in nuclear masses. We demonstrate that, unexpectedly, the strong-force-rooted isovector force gives rise to a large systematic increase of αISB\alpha_{\rm ISB} and δISBV\delta_{\rm ISB}^{\rm V} as compared to the results obtained within MR-DFT that uses Coulomb interaction as the only source of ISB. This, in turn, increases a central value of the VudV_{\rm ud} element of the CKM matrix extracted from the T=1/2T=1/2 mirrors bringing it closer to the value obtained form the purely vector superallowed 0+0+0^+ \to 0^+ transitions. In order to compute the value of VudV_{\rm ud}, we performed precision calculation of the Fermi matrix elements in A=19,21,35A=19, 21, 35, and 37 mirror nuclei using DFT-rooted configuration-interaction model that includes all relevant axially-deformed particle-hole configurations built upon Nilsson orbitals originating from the spherical sdsd shell. Our calculations yield Vud=0.9736(16)|V_{\rm ud}|=0.9736(16).Comment: 5 pages, 3 figure

    Isobaric Multiplet Mass Equation within nuclear Density Functional Theory

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    We extend the nuclear Density Functional Theory (DFT) by including proton-neutron mixing and contact isospin-symmetry-breaking (ISB) terms up to next-to-leading order (NLO). Within this formalism, we perform systematic study of the nuclear mirror and triple displacement energies, or equivalently of the Isobaric Multiplet Mass Equation (IMME) coefficients. By comparing results with those obtained within the existing Green Function Monte Carlo (GFMC) calculations, we address the fundamental question of the physical origin of the ISB effects. This we achieve by analyzing separate contributions to IMME coefficients coming from the electromagnetic and nuclear ISB terms. We show that the ISB DFT and GFMC results agree reasonably well, and that they describe experimental data with a comparable quality. Since the separate electromagnetic and nuclear ISB contributions also agree, we conclude that the beyond-mean-field electromagnetic effects may not play a dominant role in describing the ISB effects in finite nuclei

    Mirror and triplet displacement energies within nuclear DFT : Numerical stability

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    Isospin-symmetry-violating class II and III contact terms are introduced into the Skyrme energy density functional to account for charge dependence of the strong nuclear interaction. The two new coupling constants are adjusted to available experimental data on triplet and mirror displacement energies, respectively. We present preliminary results of the fit, focusing on its numerical stability with respect to the basis size.Peer reviewe

    Isospin-symmetry breaking in masses of N similar or equal to Z nuclei

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    Effects of the isospin-symmetry breaking (ISB) beyond mean-field Coulomb terms are systematically studied in nuclear masses near the N = Z line. The Coulomb exchange contributions are calculated exactly. We use extended Skyrme energy density functionals (EDFs) with proton-neutron-mixed densities, to which we add new terms breaking the isospin symmetry. Two parameters associated with the new terms are determined by fitting mirror and triplet displacement energies (MDEs and TDEs) of isospin multiplets. The new EDFs reproduce MDEs for the T = 1/2 doublets and T= 1 triplets, and TDEs for the T= 1 triplets. Relative strengths of the obtained isospin-symmetry-breaking terms are not consistent with the differences in the NN scattering lengths, a(nn), a(pp), and a(np). Based on low-energy experimental data, it seems thus impossible to delineate the strong-force ISB effects from beyond-mean-field Coulomb-energy corrections. (C) 2018 The Author(s). Published by Elsevier B.V.Peer reviewe

    Isospin-symmetry breaking in masses of N ≃ Z nuclei

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    Effects of the isospin-symmetry breaking (ISB) beyond mean-field Coulomb terms are systematically studied in nuclear masses near the N=Z line. The Coulomb exchange contributions are calculated exactly. We use extended Skyrme energy density functionals (EDFs) with proton–neutron-mixed densities, to which we add new terms breaking the isospin symmetry. Two parameters associated with the new terms are determined by fitting mirror and triplet displacement energies (MDEs and TDEs) of isospin multiplets. The new EDFs reproduce MDEs for the T=1/2 doublets and T=1 triplets, and TDEs for the T=1 triplets. Relative strengths of the obtained isospin-symmetry-breaking terms are not consistent with the differences in the NN scattering lengths, a nn, a pp, and a np. Based on low-energy experimental data, it seems thus impossible to delineate the strong-force ISB effects from beyond-mean-field Coulomb-energy corrections

    The interactive effect of dietary n-6: n-3 fatty acid ratio and vitamin E level on tissue lipid peroxidation, DNA damage in intestinal epithelial cells, and gut morphology in chickens of different ages

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    Feeding chickens diets high in n-3 fatty acids (FA) increases their incorporation into tissue lipids, but leads to oxidative stress in cells. This study investigated the effect of the dietary polyunsaturated FA ratio (PUFA n-6: n-3) and vitamin E (vE) level on DNA damage and morphological changes in the gut epithelium of chickens. One-day-old female broiler chicks (n = 176) were divided into 4 groups fed for 43 d diets with a high (HR) or low (LR) PUFA n-6: n-3 ratio and supplemented with 50 or 300 mg vE kg−1. Performance was calculated for periods of d 1 to 9, d 9 to 16, d 9 to 35, and d 9 to 42, while organs were sampled at d 9, d 17, d 36, and d 43. At d 17 and d 43, DNA damage of epithelial cells in the duodenum and jejunum was measured and duodenal and jejunal morphology was analyzed. HR diets improved FCR for the periods of d 1 to 9, d 9 to 16 and d 9 to 42, whereas the increased vE level improved FCR for the period of d 9 to 16. In the jejunum DNA damage was greater in chickens fed LR than HR diets at d 17 (P P P = 0.022), and mucosa thickness (P = 0.029) and villus height (P = 0.035) at d 43. The results indicated that feeding birds LR diets and vE levels significantly exceeding the recommendation induced DNA damage in epithelial cells, but this effect varied depending on the intestinal segment and the age of birds

    Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (VIII) HFODD (v2.73y) : A new version of the program

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    We describe the new version (v2.73y) of the code hfodd which solves the nuclear Skyrme HartreeFock or Skyrme HartreeFockBogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we have implemented the following new features: (i) full protonneutron mixing in the particlehole channel for Skyrme functionals, (ii) the Gogny force in both particlehole and particleparticle channels, (iii) linear multi-constraint method at finite temperature, (iv) fission toolkit including the constraint on the number of particles in the neck between two fragments, calculation of the interaction energy between fragments, and calculation of the nuclear and Coulomb energy of each fragment, (v) the new version 200d of the code hfbtho, together with an enhanced interface between hfbtho and hfodd, (vi) parallel capabilities, significantly extended by adding several restart options for large-scale jobs, (vii) the Lipkin translational energy correction method with pairing, (viii) higher-order Lipkin particle-number corrections, (ix) interface to a program plotting single-particle energies or Routhians, (x) strong-force isospin-symmetry-breaking terms, and (xi) the Augmented Lagrangian Method for calculations with 3D constraints on angular momentum and isospin. Finally, an important bug related to the calculation of the entropy at finite temperature and several other little significant errors of the previous published version were corrected. Program summary Title of the program:hfodd (v2.73y) Program Files doi:http://dx.doi.org/10.17632/3b28fs62wc.1 Licensing provisions: GPL v3 Programming language: FORTRAN-90 Journal reference of previous version: N. Schunck, J. Dobaczewski, J. McDonnell, W. Satula, J. Sheikh, A. Staszczak, M. Stoitsov, and P. Toivanen, Comput. Phys. Comm. 183 (2012) 166-192. Does the new version supersede the previous one: Yes Nature of problem: The nuclear mean field and an analysis of its symmetries in realistic cases are the main ingredients of a description of nuclear states. For the density functional generated by a zero-range velocity-dependent Skyrme interaction, the nuclear mean field is quasilocal. This allows for an effective and fast solution of the self-consistent HartreeFock equations, even for heavy nuclei, and for various nucleonic (n-particle n-hole) configurations, deformations, excitation energies, or angular momenta. Similarly, the local particleparticle density functional, generated by a zero-range interaction, allows for a simple implementation of pairing effects within the HartreeFockBogolyubov method. For finite-range interactions, like Coulomb, Yukawa, or Gogny interaction, the nuclear mean field becomes nonlocal, but using the spatial separability of the deformed harmonic-oscillator basis in three Cartesian directions, the self-consistent calculations can be efficiently performed. Solution method: The program uses the Cartesian harmonic oscillator basis to expand single-particle or single-quasiparticle wave functions of neutrons and protons interacting by means of the Skyrme or Gogny effective interactions and zero-range or finite-range pairing interactions. The expansion coefficients are determined by the iterative diagonalization of the mean-field Hamiltonians or Routhians which depend non-linearly on the local or nonlocal neutron, proton, or mixed protonneutron densities. Suitable constraints are used to obtain states corresponding to a given configuration, deformation or angular momentum. The method of solution has been presented in: J. Dobaczewski and J. Dudek, Comput. Phys. Comm. 102 (1997) 166. Summary of revisions: 1.Full proton-neutron mixing in the particlehole channel for Skyrme functionals was implemented. 2.The Gogny force was implemented in both particle-hole and particle-particle channels. 3.Linear multi-constraint method based on the cranking approximation of the QRPA matrix was extended at finite temperature. 4.Fission toolkit includes the constraint on the number of particles in the neck between two fragments, calculation of the interaction energy between fragments, and calculation of the nuclear and Coulomb energy of each fragment. 5.The HFBTHO module was updated to version 200d, and an enhanced interface between HFBTHO and HFODD was implemented. 6.Parallel capabilities were significantly extended by adding several restart options for large-scale jobs. 7.The Lipkin translational energy correction method with pairing was implemented. 8.Higher-order Lipkin particle-number corrections were implemented. 9.Interface to a program plotting single-particle energies or Routhians was added. 10.Strong-force isospin-symmetry-breaking terms were implemented. 11.The Augmented Lagrangian Method for calculations with 3D constraints on angular momentum and isospin was implemented. 12.An important bug related to the calculation of the entropy at finite temperature and several other little significant errors of the previous published version were corrected. Unusual features of the program: The user must have access to (i) the LAPACK subroutines zhpev, zhpevx, zheevr, or zheevd, which diagonalize complex hermitian matrices, (ii) the LAPACK subroutines dgetri and dgetrf which invert arbitrary real matrices, (iii) the LAPACK subroutines dsyevd, dsytrf and dsytri which compute eigenvalues and eigenfunctions of real symmetric matrices and (iv) the LINPACK subroutines zgedi and zgeco, which invert arbitrary complex matrices and calculate determinants, (v) the BLAS routines dcopy, dscal, dgeem and dgemv for double-precision linear algebra and zcopy, zdscal, zgeem and zgemv for complex linear algebra, or provide another set of subroutines that can perform such tasks. The BLAS and LAPACK subroutines can be obtained from the Netlib Repository at the University of Tennessee, Knoxville: http://netlib2.cs.utk.edu/. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

    High-precision mass measurements and production of neutron-deficient isotopes using heavy-ion beams at IGISOL

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    An upgraded ion-guide system for the production of neutron-deficient isotopes with heavy-ion beams has been commissioned at the IGISOL facility with an Ar-36 beam on a Ni-nat target. It was used together with the JYFLTRAP double Penning trap to measure the masses of Zr-82, Nb-84, Mo-86, Tc-88, and Ru-89 ground states and the isomeric state Tc-88(m). Of these, Ru-89 and Tc-88(m) weremeasured for the first time. The precision of measurements of Zr-82, Nb-84, and Tc-88 was significantly improved. The literature value for Mo-86 was verified. The measured states in Tc-88 were compared to shell-model calculations and additional constraints on the spins and level scheme were obtained. The masses of Mo-82 and Ru-86 have been predicted using the measured masses of their mirror partners and theoretical mirror displacement energies, resulting in more tightly bound nuclei with smaller atomic mass uncertainties than reported in the literature.Peer reviewe
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