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Nuclear Decay Schemes in the Actinium Family

Description: Abstract: "With magnetic alpha-particle and electron high-resolution spectrographs and scintillation gamma-ray spectrometers, a study was made of the nuclear decay of a number of members of the actinium family - U-235, Th-227, Ra-223, Em-219, Po-215, and Bi-211. Decay schemes are presented for each of these nuclides, together with such correlations as are possible with present theoretical nuclear models. The decay scheme of U-235 and a portion of that of Th-227 are interpretable in terms of the collective model and a spherical shell-model characteristics; however, the intermediate nuclides present complexities not well understood."
Date: July 1957
Creator: Pilger, Richard Christian, Jr.
Partner: UNT Libraries Government Documents Department

Reconnection in NIMROD: Model, Predictions, Remedies

Description: It is shown that in NIMROD the formation of closed current configurations, occurring only after the voltage is turned off, is due to the faster resistive decay of nonsymmetric modes compared to the symmetric projection of the 3D steady state achieved by gun injection. Implementing Spitzer resistivity is required to make a definitive comparison with experiment, using two experimental signatures of the model discussed in the paper. If there are serious disagreements, it is suggested that a phenomenological hyper-resistivity be added to the n = 0 component of Ohm's law, similar to hyper-resistive Corsica models that appear to fit experiments. Hyper-resistivity might capture physics at small scale missed by NIMROD. Encouraging results would motivate coupling NIMROD to SPICE with edge physics inspired by UEDGE, as a tool for experimental data analysis.
Date: June 25, 2003
Creator: Fowler, T K; Bulmer, R H; Cohen, B I & Hau, D D
Partner: UNT Libraries Government Documents Department

K-Meson Degeneracies

Description: Abstract: "Some discussion is given of the possible real and charge parity degeneracies of K mesons. An explicit model is used to illustrate the superselection rule, which forbids the K meson to be a mixture of intrinsic parity states and at the same time conserve parity in decay. The discussion is extended to charge parity; the 01, 02 scheme appears to be more than an exercise in polarization phenomenons and to involve a radically new basic assumption--namely, that the 0-0 and 0-(-0) are degenerate states. The [tau]-0 is compared with the 02 as a long-lived K meson, and a method of experimental distinction is described."
Date: October 1956
Creator: Peaslee, D. C.
Partner: UNT Libraries Government Documents Department

Occurrence of the 4n + 1 Series in Nature

Description: "A small quantity of a Np-237, the long-lived ancestor of the 4n + 1 series, has been isolated from a natural source. The Th-229 content of the Th-230 obtained from Belgian Congo pitchblende concentrate and of Th-232 obtained from Brazilian monazite has been determined indirectly through isolation of the Ac-225 daughter. The mass ratio of Np-237 to U-238 in the Belgian Congo pitchblende concentrate has been determined as (1.8 +/- 0.4) x 10-(-12). The mass ratio of U-233 to U-238 in the same ore deposit is found to be (1.3 +/- 0.2) x 10-(-13). The ratio of the respective neutron-capture cross sections of U-238 in the ore body for the (n, 2n) and (n, gamma) reactions is calculated to be (1.3 +/- 0.6) x 10-(-3) on the basis of the relative Np-237 and Pu-239 contents."
Date: April 10, 1952
Creator: Peppard, D. F.; Mason, G. W.; Gray, P. R. & Mech, J. F.
Partner: UNT Libraries Government Documents Department

Neutron Distributions Measured with Beta Decays and Photographic Emulsions

Description: Abstract: "A method has been developed for observing the "fine structure" of neutron flux distribution. Difference in neutron flux in regions a half a millimeter apart have been measured. Examples in which this resolution has been useful are given. In the case of a polythene ball, three-fourths of an inch in diameter, in the center of the Little Eva reactor, the effective neutron flux varies 75% of the unperturbed value between two readings a tenth of an inch apart."
Date: 1956
Creator: Young, Dwight S.
Partner: UNT Libraries Government Documents Department

A Correlation of the Habitat Factors with the Quantity of Bacterial Colonies as Observed by the Direct Microscopic Method on Twenty Soils of Denton County, Texas

Description: The aim of this study is to determine what factors are most important in controlling the number of bacterial colonies found in twent represntative Denton County (Texas) soils during the growing season.
Date: August 1937
Creator: Roach, Cornelia Ann
Partner: UNT Libraries

A possible hadronic excess in psi(2S) decay and the rho pi puzzle

Description: We study the so-called {rho}{pi} puzzle of the {psi}(2S) decay by incorporating two inputs; the relative phase between the one-photon and the gluonic decay amplitude, and a possible hadronic excess in the inclusive nonelectromagnetic decay rate of {psi}(2S). We look into the possibility that the hadronic excess in {psi}(2S) originates from a decay process of long-distance origin which is absent from the J/{upsilon} decay. We propose that the amplitude of this additional process happens to nearly cancel the short-distance gluonic amplitude in the exclusive decay {psi}(2S) {yields} 1{sup -}0{sup -} and turn the sum dominantly real in contrast to the J/{psi} decay. We present general consequences of this mechanism and survey two models which might possibly explain the source of this additional amplitude.
Date: November 9, 2000
Creator: Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

Subaërial Decay of Rocks and Origin of the Red Color of Certain Formations

Description: A report that focuses on the widespread decay of the surface rocks throughout the Appalachian region. It also focuses on the iron-stained sands which result from subaërial decay of crystalline rocks that agree in many ways with iron-stained sands forming certain geologic formations.
Date: 1889
Creator: Russell, Israel Cook
Partner: UNT Libraries Government Documents Department

Squark Mixing Contributions to CP violating phase gamma

Description: We investigate the possibility that the CP violation due to the soft supersymmetry breaking terms in squark mixing can give significant contributions to the various $\gamma$ related parameters in B decays, different from those of the Standard Model. We derive the new limits on $(\delta^u_12)_LL,LR,RR$ and on $(\delta^d_23)_LL,LR,RR$ from the recent data on $D^0$--$\barD^0$ oscillation as well as those on $B_s^0$--$\barB_s^0$ oscillation. We show that, together with all the other constraints, the currents limits on these parameters still allow large contributions to the CP violating phases in $B_s^0$--$\bar{B_s}^0$ as well as $D^0$--$\barD^0$ oscillations which will modify some of the proposed measurements of $\gamma$ parameters in CP violating B decays. However, the current constraints already dictate that the one-loop squark mixing contributions to various B decay amplitudes cannot be competitive with that of the Standard Model (SM), at least for those B decay modes which are dominated the tree level amplitudes within the SM, and therefore they are not significant in contributing to CP asymmetries in the corresponding B decays.
Date: September 17, 2001
Creator: Chang, Darwin; Chang, We-Fu; Keung, Wai-Yee; Sinha, Nita & Sinha, Rahul
Partner: UNT Libraries Government Documents Department

Neutrinoless Double Beta Decay in Light of SNO Salt Data

Description: In the SNO data from its salt run, probably the most significant result is the consistency with the previous results without assuming the 8B energy spectrum. In addition, they have excluded the maximal mixing at a very high confidence level. This has an important implication on the double beta decay experiments. For the inverted or degenerate mass spectrum, we find bar<m_nu>_ee bar> 0.013 eV at 95percent CL, and the next generation experiments can discriminate Majorana and Dirac neutrinos if the invertedor degenerate mass spectrum will be confirmed by the improvements in cosmology, tritium data beta decay, or long-baseline oscillation experiments.
Date: September 11, 2003
Creator: Murayama, Hitoshi & Pena-Garay, Carlos
Partner: UNT Libraries Government Documents Department

A Possible Test of Time Reversal in Mu-Meson Decay

Description: Report that discusses the possibility of testing the T-invariance in μ-meson decay. The author describes a past experiment performed by Lee and Yang, as well as the specifics of the proposed experiment to test the time reversal in μ-meson decay.
Date: March 4, 1957
Creator: Kotani, T.
Partner: UNT Libraries Government Documents Department

[Delta]I = 1/2 Rule for Non-Leptonic Strangeness-Changing Decay Processes

Description: Gell-Mann and Pais were the first to suggest that the non-leptonic decay processes of strange particles may be subject to an isospin selection rule, allowing only those decay transitions which involve a change [delta]I = 1/2 in to total isopin of the system. At present, however, there is really no theoretical framework for the description of weak interactions into which this selection rule fits in a natural and compelling way. The report includes sections on the 91) decay processes of the [caret] hyperon, (2) decay processes, (3) [complex conjugate] decay processes, and (6) K[pi]3 decay processes. We have considered the evidence on all of the known non-leeptonic non-radiative decay modes of strange particles. All of this evidence is in good qualitative accord with the [delta]I = 1/2 selection rule.
Date: December 2, 1963
Creator: Dalitz, R. H. (Richard Henry), 1925-2006.
Partner: UNT Libraries Government Documents Department

Radiative higgs boson decays H {yields} f{anti f}{gamma}

Description: Higgs boson radiative decays of the form H {r_arrow} f{ovr f}{gamma} are calculated in the Standard Model using the complete one-loop expressions for the decay amplitudes. Contributions to the radiative width from leptons and light quarks are given. We also present e{ovr e} invariant mass distributions for H {r_arrow} e{ovr e}{gamma}, which illustrate the importance of the photon pole contribution and the effects of the box diagrams. 4 refs., 6 figs.
Date: October 10, 1996
Creator: Abbasabadi, A.; Bowser-Chao, D.; Repko, W.W. & Dicus, D.A.
Partner: UNT Libraries Government Documents Department

Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

Description: The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29} pb is approximately a factor of four larger than compared to recent model predictions. The influences of the N = 152 and Z = 108 shells on alpha decay properties are discussed.
Date: May 7, 2007
Creator: Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf et al.
Partner: UNT Libraries Government Documents Department

Parametric forms and the inductive response of a permeable conducting sphere

Description: At early time, the time derivative of the response of isolated conductive bodies to step function excitation decays as t-1/2 (under a quasi-static approximation). One simple parametric form for the response with correct early time behavior is k'(1 + t1/2/a1/2)-beta e-t/gamma. For a conducting magnetic sphere, parameter values are determined from the high and low frequency limit responses, together with two time scales taken from the form of the analytic solution. Parameters alpha and gamma correspond to transition times, for transition from an early time t-1/2 derivative response, and to late time exponential decay. For conducting spheres with high permeability, increasing the permeability moves the transition from early time behavior earlier in inverse proportion to the relative permeability mu r, and increases the time constant of the late time decay in proportion to mu r. Magnitude parameter k' corresponds to the difference between high frequency and low frequency limit responses.
Date: December 11, 2003
Creator: Smith, J. Torquil; Morrison, H. Frank & Becker, Alex
Partner: UNT Libraries Government Documents Department

The Decay of the Yoknapatawpha Aristocracy in the Works of William Faulkner

Description: This study consists of an examination in detail of those facets of character, and conduct arising from character, which specifically account for the decay of the aristocracy of Yoknapatawpha; and by way of emphasis, of the specifically regenerative attitudes and actions which have sufficed to preserve various individuals of this class who have endured as fully adequate human beings.
Date: June 1962
Creator: Pyland, Joel L.
Partner: UNT Libraries

The Half Life of Am²⁴³

Description: This report calculates the alpha half-life of americium-243 and reporting a measurement error.
Date: 1953
Creator: Diamond, Herbert; Fields, Paul R.; Mech, Joseph; Inghram, Mark Gordon & Hess, David C.
Partner: UNT Libraries Government Documents Department

Determination of half life of polonium-210 by counting: final report

Description: Introduction: "A number of determination have been made of the half life of polonium-210 by calorimetry. Counting affords an entirely different method of determining half lives and requires only a small amount of activity. Therefore for comparison a half-life determination by counting was undertaken with a sample of approximately 0.5 millicurie of polonium."
Date: June 1, 1951
Creator: Curtis, Mary Lou
Partner: UNT Libraries Government Documents Department