Sample records for milliseconds alpha decay

  1. Alpha decay chains from element 113

    E-Print Network [OSTI]

    P. Roy Chowdhury; D. N. Basu; C. Samanta

    2007-04-30T23:59:59.000Z

    Theoretical estimates of $\\alpha$-decay half lives of several nuclei in the decay from element 113 are presented. Calculations in a WKB framework using DDM3Y interaction and experimental Q-values are in good agreement with the experimental data. Half life calculations are found to be quite sensitive to the Q-values and angular momenta transfers. Calculated decay lifetime decreases, owing to more penetrability as well as thinner barrier, as Q-value increases. Deviations to this predominant behaviour observed in some recent experimental data may be attributed to non zero spin-parities in some cases.

  2. Discovery of the $^{151}$Eu $\\alpha$ decay

    E-Print Network [OSTI]

    Casali, N; Orio, F; Pattavina, L; Beeman, J W; Bellini, F; Cardani, L; Dafinei, I; Di Domizio, S; Di Vacri, M L; Gironi, L; Kosmyna, M B; Nazarenko, B P; Nisi, S; Pessina, G; Piperno, G; Pirro, S; Rusconi, C; Shekhovtsov, A N; Tomei, C; Vignati, M

    2013-01-01T23:59:59.000Z

    We report on the observation of the $^{151}$Eu $\\alpha$ decay to the ground state of $^{147}$Pm. We measured a half-life of T_{1/2}=(4.62$\\pm$0.95(stat.)$\\pm$0.68(syst.))$\\times 10^{18}$ y and a Q-value of 1948.9$\\pm$6.9 keV, using a 6.15 g Li$_6$Eu(BO$_3$)$_3$ crystal operated as scintillating bolometer.

  3. Electron Screening and Alpha-Decay

    E-Print Network [OSTI]

    Agatino Musumarra

    2010-10-21T23:59:59.000Z

    The interplay between nuclear and electromagnetic forces in astrophysical relevant reactions at very low energies is nowadays one of the major subjects of investigation in nuclear astrophysics. Puzzling results concerning the role of Electron Screening (ES) on cross sections of reactions involving light nuclei at low energy open a Pandora pot and many new questions rise on the limits and reliability of the present interpretation of the screening enhancement factor. In the present paper we discuss the simplest physical case where the ES plays an important role in order to have unambiguous determination of ES energy in a clear theoretical scenario. This is the case of alpha-decay of heavy mass nuclei. We deduce the correct sudden and adiabatic limit for such a system including the important relativistic corrections. Then we demonstrate rigorously how in this case the calculation of the sudden and the adiabatic limits leads to the same result. In order to get this result we use the Hellmann-Feynman theorem. After computing the electron screening energy for some systems we discuss the strong modifications of alpha-decay systematic due to electron screening. We conclude proposing a measurement of alpha-decay lifetime of bare nuclei in order to directly deduce ES Energy for heavy nuclei laying in the mass region around 210-240 u.

  4. Alpha-nucleus potential for alpha-decay and sub-barrier fusion

    E-Print Network [OSTI]

    V. Yu. Denisov; H. Ikezoe

    2005-10-27T23:59:59.000Z

    The set of parameters for alpha-nucleus potential is derived by using the data for both the alpha-decay half-lives and the fusion cross-sections around the barrier for reactions alpha+40Ca, alpha+59Co, alpha+208Pb. The alpha-decay half-lives are obtained in the framework of a cluster model using the WKB approximation. The evaluated alpha-decay half-lives and the fusion cross-sections agreed well with the data. Fusion reactions between alpha-particle and heavy nuclei can be used for both the formation of very heavy nuclei and spectroscopic studies of the formed compound nuclei.

  5. Electron shell and the alpha-decay

    E-Print Network [OSTI]

    Sergey Yu. Igashov; Yury M. Tchuvil'sky

    2012-12-03T23:59:59.000Z

    The ratio of the alpha-decay widths of a bare nucleus and the related atom is calculated. Both the change of the form and thus the penetrability of the potential barrier and the effect of reflection in the classically-allowed region appearing due to the electron shell are taken into account in the calculations of this ratio. The contribution of each of these two effects is of one and the same order of magnitude. For long-lived radioactive samples the values of the total effect turn out to be somewhat below 1 percent.

  6. Possible stimulation of nuclear alpha-decay by superfluid helium

    E-Print Network [OSTI]

    A. L. Barabanov

    2009-09-03T23:59:59.000Z

    It is suggested that superfluid helium (condensate of 4-He atoms) may stimulate nuclear alpha-decay in a situation when an alpha-emitter moves through superfluid helium with fine-tuned velocity, so that the backward-emitted alpha-particle is at rest in the laboratory frame. It is shown that the probability of stimulated alpha-decay in this case may be sizable enough to be detected.

  7. alpha decay chains: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Das; G. Gangopadhyay 2004-03-12 46 Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments Nuclear Experiment (arXiv) Summary: The Majorana Experiment...

  8. New experimental limits on the alpha decays of lead isotopes

    E-Print Network [OSTI]

    J. W. Beeman; F. Bellini; L. Cardani; N. Casali; S. Di Domizio; E. Fiorini; L. Gironi; S. S. Nagorny; S. Nisi; F. Orio; L. Pattavina; G. Pessina; G. Piperno; S. Pirro; E. Previtali; C. Rusconi; C. Tomei; M. Vignati

    2012-12-12T23:59:59.000Z

    For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg.

  9. E-Print Network 3.0 - alpha decay scheme Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  10. E-Print Network 3.0 - alpha-decaying 9- isomer Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  11. E-Print Network 3.0 - alpha decay properties Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  12. E-Print Network 3.0 - alpha decay stability Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  13. E-Print Network 3.0 - alpha decay widths Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  14. E-Print Network 3.0 - alpha decay energies Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  15. E-Print Network 3.0 - alpha decay cluster Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship for the alpha decay... life-time was derived on the ground of the fission theory of alpha ... Source: Ecole Polytechnique, Centre de mathmatiques Collection:...

  16. E-Print Network 3.0 - alpha decay detection Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Collection: Chemistry 30 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Summary: Alpha Backgrounds and Their...

  17. Estimation of the alpha decay half-lives D. N. Poenaru and M. Ivascu

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes }, based on the fission theory of alpha decay [16] have been derived and was briefly presented in refe

  18. Detection of the Natural Alpha Decay of Tungsten

    E-Print Network [OSTI]

    C. Cozzini; G. Angloher; C. Bucci; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; B. Majorovits; V. Mikhailik; J. Ninkovic; F. Petricca; W. Potzel; F. Proebst; Y. Ramachers; W. Rau; M. Razeti; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; W. Westphal; H. Wulandari

    2004-10-26T23:59:59.000Z

    The natural alpha decay of 180W has been unambiguously detected for the first time. The alpha peak is found in a (gamma,beta and neutron)-free background spectrum. This has been achieved by the simultaneous measurement of phonon and light signals with the CRESST cryogenic detectors. A half-life of T1/2 = (1.8 +- 0.2) x 10^18 y and an energy release of Q = (2516.4 +- 1.1 (stat.) +- 1.2 (sys.)) keV have been measured. New limits are also set on the half-lives of the other naturally occurring tungsten isotopes.

  19. {alpha} decay and recoil decay tagging studies of {sup 183}Tl

    SciTech Connect (OSTI)

    Raddon, P.M.; Jenkins, D.G.; O'Leary, C.D.; Simons, A.J.; Wadsworth, R. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Andreyev, A.N.; Page, R.D. [Oliver Lodge Laboratory, Department of Physics, University of Liverpool, Liverpool, L69 7ZE (United Kingdom); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kondev, F.G. [Technology Development Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Enqvist, T.; Greenlees, P.T.; Jones, P.M.; Julin, R.; Juutinen, S.; Kettunen, H.; Leino, M.; Leppaenen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P. [Department of Physics, University of Jyvaeskylae, FIN-40351, Jyvaeskylae (Finland)] [and others

    2004-12-01T23:59:59.000Z

    High-spin states in the nucleus {sup 183}Tl have been studied using the recoil decay tagging and recoil tagging techniques. The data have enabled new structures to be identified which are believed to be based on prolate f{sub 7/2}, h{sub 9/2}, and oblate h{sub 9/2} configurations. In addition, the prolate i{sub 3/2} structure has also been extended. The systematics of the newly identified structures will be discussed. The {alpha} decay of {sup 183}Tl has also been investigated. Examination of both delayed and prompt {gamma} rays in coincidence with the prominent 6333-keV {alpha} decay, together with an investigation of the effects of the summing of L electrons, allow assignment of transitions and the construction of tentative low-spin decay schemes for {sup 179}Au and {sup 175}Ir.

  20. E-Print Network 3.0 - additional collateral alpha-decay Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for Physics... semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes... of the double magic nucleus 100Sn was studied 7....

  1. E-Print Network 3.0 - alpha-decay branching ratios Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for Physics... semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes... of the double magic nucleus 100Sn was studied 7....

  2. First observation of /sup 162/Hf decay completion of an alpha -decay chain

    E-Print Network [OSTI]

    Schrewe, U J; Hagberg, E; Hardy, J C; Koslowsky, V T; Schmeing, H; Sharma, K S

    1981-01-01T23:59:59.000Z

    The new isotope /sup 162/Hf (T/sub 1/2/=(37.6+or-0.8)s) is produced in a /sup 142/Nd (/sup 24/Mg,4n) reaction. The activities produced in this reaction are transported to a measuring station by use of a He- jet system. Decay properties are observed with alpha -, gamma -, and gamma - gamma -spectroscopy. The Z-assignment of the new isotope is based on a cross bombardment on /sup 141/Pr target and on the results of a gamma -X-ray coincidence measurement. The mass assignment is deduced from the excitation function measurements. From the measured alpha -decay energy E/sub alpha /=4308 (10) keV new mass values are derived for /sup 162/Hf, /sup 166/W, /sup 170/Os, /sup 174/Pt, and /sup 178/Hg. These new mass values make it possible to establish systematics of two-proton and one-proton binding energies far from stability. (20 refs).

  3. Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Robert A. Johnson Chair of the Supervisory Committee: Professor John F. Wilkerson Physics The observation of neutrinoless double-beta decay

  4. Self-energy O(alpha^2) correction to the positronium decay rate

    E-Print Network [OSTI]

    R. N. Faustov; A. P. Martynenko

    2000-02-26T23:59:59.000Z

    Self-energy corrections of order O(alpha^2) to the parapositronium and orthopositronium decay rates are calculated. Numerical values of the corresponding coefficients are B_p=-3.74, B_o=2.02.

  5. Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments

    E-Print Network [OSTI]

    R. A. Johnson; T. H. Burritt; S. R. Elliott; V. M. Gehman; V. E. Guiseppe; J. F. Wilkerson

    2011-12-30T23:59:59.000Z

    The Majorana Experiment will use arrays of enriched HPGe detectors to search for the neutrinoless double-beta decay of 76Ge. Such a decay, if found, would show lepton-number violation and confirm the Majorana nature of the neutrino. Searches for such rare events are hindered by obscuring backgrounds which must be understood and mitigated as much as possible. A potentially important background contribution to this and other double-beta decay experiments could come from decays of alpha-emitting isotopes in the 232Th and 238U decay chains on or near the surfaces of the detectors. An alpha particle emitted external to an HPGe crystal can lose energy before entering the active region of the detector, either in some external-bulk material or within the dead region of the crystal. The measured energy of the event will only correspond to a partial amount of the total kinetic energy of the alpha and might obscure the signal from neutrinoless double-beta decay. A test stand was built and measurements were performed to quantitatively assess this background. We present results from these measurements and compare them to simulations using Geant4. These results are then used to measure the alpha backgrounds in an underground detector in situ. We also make estimates of surface contamination tolerances for double-beta decay experiments using solid-state detectors.

  6. Alpha Backgrounds for HPGe Detectors in Neutrinoless Double-Beta Decay Experiments

    SciTech Connect (OSTI)

    Johnson, R. A. [University of Washington, Seattle; Burritt, T. H. [University of Washington, Seattle; Elliott, S. R. [Los Alamos National Laboratory (LANL); Gehman, V. M. [Los Alamos National Laboratory (LANL); Guiseppe, V.E. [University of South Dakota; Wilkerson, J. F. [UNC/Triangle Univ. Nucl. Lab, Durham, NC/ORNL

    2012-01-01T23:59:59.000Z

    The Majorana Experiment will use arrays of enriched HPGe detectors to search for the neutrinoless double-beta decay of 76Ge. Such a decay, if found, would show lepton-number violation and confirm the Majorana nature of the neutrino. Searches for such rare events are hindered by obscuring backgrounds which must be understood and mitigated as much as possible. A potentially important background contribution to this and other double-beta decay experiments could come from decays of alpha-emitting isotopes in the 232Th and 238U decay chains on or near the surfaces of the detectors. An alpha particle emitted external to an HPGe crystal can lose energy before entering the active region of the detector, either in some external-bulk material or within the dead region of the crystal. The measured energy of the event will only correspond to a partial amount of the total kinetic energy of the alpha and might obscure the signal from neutrinoless double-beta decay. A test stand was built and measurements were performed to quantitatively assess this background. We present results from these measurements and compare them to simulations using Geant4. These results are then used to measure the alpha backgrounds in an underground detector in situ. We also make estimates of surface contamination tolerances for double-beta decay experiments using solid-state detectors.

  7. ALPHA-DECAY STUDIES IN THE HEAVY-ELEMENT REGION

    E-Print Network [OSTI]

    Hummel, John Philip

    2010-01-01T23:59:59.000Z

    ± 0.3 days. Various ion-chamber measurements of the alpha-of about· 0.1%. These ion-chamber measurements represent theis somewhat higher than the ion-chamber measurement quoted

  8. Can a many-nucleon structure be visible in bremsstrahlung emission during $\\alpha$ decay?

    E-Print Network [OSTI]

    Maydanyuk, Sergei P; Zou, Li-Ping

    2015-01-01T23:59:59.000Z

    We analyze if the nucleon structure of the $\\alpha$ decaying nucleus can be visible in the experimental bremsstrahlung spectra of the emitted photons which accompany such a decay. We develop a new formalism of the bremsstrahlung model taking into account distribution of nucleons in the $\\alpha$ decaying nuclear system. We conclude the following: (1) After inclusion of the nucleon structure into the model the calculated bremsstrahlung spectrum is changed very slowly for a majority of the $\\alpha$ decaying nuclei. However, we have observed that visible changes really exist for the $^{106}{\\rm Te}$ nucleus ($Q_{\\alpha}=4.29$ MeV, $T_{1/2}$=70 mks) even for the energy of the emitted photons up to 1 MeV. This nucleus is a good candidate for future experimental study of this task. (2) Inclusion of the nucleon structure into the model increases the bremsstrahlung probability of the emitted photons. (3) We find the following tendencies for obtaining the nuclei, which have bremsstrahlung spectra more sensitive to the ...

  9. Plutonium-238 alpha-decay damage study of the ceramic waste form.

    SciTech Connect (OSTI)

    Frank, S M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Barber, T L [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Cummings, D G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; DiSanto, T [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Esh, D W [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; Giglio, J J [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Goff, K M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Johnson, S G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Kennedy, J R [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Jue, J-F [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Noy, M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; O'Holleran, T P [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Sinkler, W [UOP LLC, 25 E Algonquin Road, Des Plaines, IL 60017

    2006-03-27T23:59:59.000Z

    An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with {sup 238}Pu which has a much greater specific activity than {sup 239}Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10{sup 18} alpha-decays/gram of material. An equivalent time period for a similar dose of {sup 239}Pu would require approximately 1100 years. After four years of exposure to {sup 238}Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the {sup 238}Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) {sup 238}Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell volume has expanded slightly by 0.3% again, presumably due to alpha-decay damage. (5) No bulk sample swelling was observed. (6) No amorphization of sodalite or actinide bearing phases was observed after four years of alpha-decay damage. (7) No microcracks or phase de-bonding were observed in waste form samples aged for four years. (8) In some areas of the {sup 238}Pu doped ceramic waste form material bubbles and voids were found. Bubbles and voids with similar size and density were also found in ceramic waste form samples without actinide. These bubbles and voids are interpreted as pre-existing defects. However, some contribution to these bubbles and voids from helium gas can not be ruled out. (9) Chemical durability of {sup 238}Pu CWF has not changed significantly after four years of alpha-decay exposure except for an increase in the release of salt components and Pu. Still, the plutonium release from CWF is very low at less than 0.005 g/m{sup 2}.

  10. Quantum tunneling in ^{277}112 and its alpha-decay chain

    E-Print Network [OSTI]

    C. Samanta; D. N. Basu; P. Roy Chowdhury

    2007-08-31T23:59:59.000Z

    The $\\alpha$-decay half lives of nuclei in the decay from element $^{277}112$ are calculated in a WKB framework using DDM3Y interaction and experimental Q-values. Theoretical estimation of half lives in the same quantum tunneling model, using Q-values from the mass formula of Muntian-Hofmann-Patyk-Sobiczewski, are also presented. Calculated results furnish corroborating evidence for the experimental findings at RIKEN and GSI. Certain discrepancies indicate necessity of a better mass formula. Further experimental data with higher statistics would also be useful.

  11. Systematic calculations of $\\alpha$-decay half-lives with an improved empirical formula

    E-Print Network [OSTI]

    Wang, Z Y; Liu, Q; Guo, J Y

    2015-01-01T23:59:59.000Z

    Based on the recent data in NUBASE2012, an improved empirical formula for evaluating the $\\alpha$-decay half-lives is presented, in which the hindrance effect resulted from the change of the ground state spins and parities of parent and daughter nuclei is included, together with a new correction factor for nuclei near the shell closures. The calculated $\\alpha$-decay half-lives are found to be in better agreements with the experimental data, and the corresponding root-mean-square (rms) deviation is reduced to $0.433$ when the experimental $Q$-values are employed. Furthermore, the $Q$-values derived from different nuclear mass models are used to predict $\\alpha$-decay half-lives with this improved formula. It is found that the calculated half-lives are very sensitive to the $Q$-values. Remarkably, when mass predictions are improved with the radial basis function (RBF), the resulting rms deviations can be significantly reduced. With the mass prediction from the latest version of Weizs\\"{a}cker-Skyrme (WS4) mode...

  12. A new semiempirical formula for the alpha decay half-lives D. N. Poenaru, M. Ivascu and D. Mazilu

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    life-time was derived on the ground of the fission theory of alpha decay. It takes into consideration discovered. On the other hand, new effects can be introduced. Our new equation is based on the fission theory

  13. Analysis of nuclear materials by energy dispersive x-ray fluorescence and spectral effects of alpha decay

    SciTech Connect (OSTI)

    Worley, Christopher G [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, {sup 239}Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect spectra from plutonium, americium, and a Pu-contaminated steel sample. The plutonium sample was also analyzed by wavelength dispersive XRF to demonstrate spectral differences observed when using these very different instruments.

  14. On spontaneous fission and alpha-decay half-lives of atomic nuclei

    E-Print Network [OSTI]

    K. Pomorski; M. Warda; A. Zdeb

    2015-01-16T23:59:59.000Z

    It is shown, that the Gamow-like model with only one adjustable parameter - radius constant is able to reproduce well the alpha-decay half-lives for all even-even nuclei with the proton number larger than 50. The systematics for odd-A and odd-odd isotopes can be also well described when ones introduces an additional hindrance factor. Similar model based on the W. J. Swiatecki idea from 1955 is developed to reproduce the spontaneous fission half-lives of transactinide nuclei. The achieved accuracy of reproduction of the data is better than that obtained in more advanced theories.

  15. Effects of alpha beam on the parametric decay of a parallel propagating circularly polarized Alfven wave: Hybrid simulations

    SciTech Connect (OSTI)

    Gao, Xinliang; Lu, Quanming; Tao, Xin; Hao, Yufei; Wang, Shui [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 (China)] [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 (China)

    2013-09-15T23:59:59.000Z

    Alfven waves with a finite amplitude are found to be unstable to a parametric decay in low beta plasmas. In this paper, the parametric decay of a circularly polarized Alfven wave in a proton-electron-alpha plasma system is investigated with one-dimensional (1-D) hybrid simulations. In cases without alpha particles, with the increase of the wave number of the pump Alfven wave, the growth rate of the decay instability increases and the saturation amplitude of the density fluctuations slightly decrease. However, when alpha particles with a sufficiently large bulk velocity along the ambient magnetic field are included, at a definite range of the wave numbers of the pump wave, both the growth rate and the saturation amplitude of the parametric decay become much smaller and the parametric decay is heavily suppressed. At these wave numbers, the resonant condition between the alpha particles and the daughter Alfven waves is satisfied, therefore, their resonant interactions might play an important role in the suppression of the parametric decay instability.

  16. Predictions of Alpha Decay Half lives of Heavy and Superheavy Elements

    E-Print Network [OSTI]

    C. Samanta; P. Roy Chowdhury; D. N. Basu

    2007-05-28T23:59:59.000Z

    Theoretical estimates for the lifetimes of several isotopes of heavy elements with Z=102-120 are presented by calculating the quantum mechanical tunneling probability in a WKB framework and using microscopic nucleus-nucleus potential obtained by folding the densities of interacting nuclei with the DDM3Y effective nuclear interaction. The $\\alpha$-decay half lives calculated in this formalism using the experimental $Q$-values are in good agreement over a wide range of experimental data. Half lives are also calculated using $Q$-values extracted from two mass formulae. The Viola-Seaborg-Sobiczewski (VSS) estimates of $\\alpha$-decay half lives with the same $Q$-values are presented for comparison. The half life calculations are found to be quite sensitive to the choice of $Q$-values. Comparison with the experimental data delineates the inadequacies of older mass predictions in the domain of heavy and superheavy elements as compared to the newer one by Muntian-Hofmann-Patyk-Sobiczewski, and highlights necessity of a more accurate mass formula which can predict $Q$-values with even higher precision.

  17. Measurements of the ion fraction and mobility of alpha and beta decay products in liquid xenon using EXO-200

    E-Print Network [OSTI]

    Albert, J B; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; O'Sullivan, K; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Robinson, A; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wright, J D; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01T23:59:59.000Z

    Alpha decays in the EXO-200 detector are used to measure the fraction of charged $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Bi}$ daughters created from alpha and beta decays, respectively. $^{222}\\mathrm{Rn}$ alpha decays in liquid xenon (LXe) are found to produce $^{218}\\mathrm{Po}^{+}$ ions $50.3 \\pm 3.0\\%$ of the time, while the remainder of the $^{218}\\mathrm{Po}$ atoms are neutral. The fraction of $^{214}\\mathrm{Bi}^{+}$ from $^{214}\\mathrm{Pb}$ beta decays in LXe is found to be $76.4 \\pm 5.7\\%$, inferred from the relative rates of $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Po}$ alpha decays in the LXe. The average velocity of $^{218}\\mathrm{Po}$ ions is observed to decrease for longer drift times. Initially the ions have a mobility of $0.390 \\pm 0.006~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$, and at long drift times the mobility is $0.219 \\pm 0.004~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$. Time constants associated with the change in mobility during drift of the $^{218}\\mathrm{Po}^{+}$ ions are found to be propor...

  18. Measurements of the ion fraction and mobility of alpha and beta decay products in liquid xenon using EXO-200

    E-Print Network [OSTI]

    J. B. Albert; D. J. Auty; P. S. Barbeau; D. Beck; V. Belov; M. Breidenbach; T. Brunner; A. Burenkov; G. F. Cao; C. Chambers; B. Cleveland; M. Coon; A. Craycraft; T. Daniels; M. Danilov; S. J. Daugherty; C. G. Davis; J. Davis; S. Delaquis; A. Der Mesrobian-Kabakian; R. DeVoe; T. Didberidze; A. Dolgolenko; M. J. Dolinski; M. Dunford; W. Fairbank Jr.; J. Farine; W. Feldmeier; P. Fierlinger; D. Fudenberg; R. Gornea; K. Graham; G. Gratta; C. Hall; M. Hughes; M. J. Jewell; X. S. Jiang; A. Johnson; T. N. Johnson; S. Johnston; A. Karelin; L. J. Kaufman; R. Killick; T. Koffas; S. Kravitz; A. Kuchenkov; K. S. Kumar; D. S. Leonard; C. Licciardi; Y. H. Lin; J. Ling; R. MacLellan; M. G. Marino; B. Mong; D. Moore; R. Nelson; K. O'Sullivan; A. Odian; I. Ostrovskiy; A. Piepke; A. Pocar; C. Y. Prescott; A. Robinson; P. C. Rowson; J. J. Russell; A. Schubert; D. Sinclair; E. Smith; V. Stekhanov; M. Tarka; T. Tolba; R. Tsang; K. Twelker; J. -L. Vuilleumier; A. Waite; J. Walton; T. Walton; M. Weber; L. J. Wen; U. Wichoski; J. D. Wright; J. Wood; L. Yang; Y. -R. Yen; O. Ya. Zeldovich

    2015-06-01T23:59:59.000Z

    Alpha decays in the EXO-200 detector are used to measure the fraction of charged $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Bi}$ daughters created from alpha and beta decays, respectively. $^{222}\\mathrm{Rn}$ alpha decays in liquid xenon (LXe) are found to produce $^{218}\\mathrm{Po}^{+}$ ions $50.3 \\pm 3.0\\%$ of the time, while the remainder of the $^{218}\\mathrm{Po}$ atoms are neutral. The fraction of $^{214}\\mathrm{Bi}^{+}$ from $^{214}\\mathrm{Pb}$ beta decays in LXe is found to be $76.4 \\pm 5.7\\%$, inferred from the relative rates of $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Po}$ alpha decays in the LXe. The average velocity of $^{218}\\mathrm{Po}$ ions is observed to decrease for longer drift times. Initially the ions have a mobility of $0.390 \\pm 0.006~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$, and at long drift times the mobility is $0.219 \\pm 0.004~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$. Time constants associated with the change in mobility during drift of the $^{218}\\mathrm{Po}^{+}$ ions are found to be proportional to the electron lifetime in the LXe.

  19. On the possibility to search for double beta decay of initially unstable (alpha/beta radioactive) nuclei

    E-Print Network [OSTI]

    V. I. Tretyak; F. A. Danevich; S. S. Nagorny; Yu. G. Zdesenko

    2004-04-13T23:59:59.000Z

    Possibilities to search for double beta decay of alpha/beta unstable nuclei, many of which have higher energy release than "conventional" (beta stable) double beta decay candidates, are discussed. First experimental half-life limits on double beta decay of radioactive nuclides from U and Th families (trace contaminants of the CaWO_4, CdWO_4 and Gd_2SiO_5 scintillators) were established by reanalyzing the data of low-background measurements in the Solotvina Underground Laboratory with these detectors (1734 h with CaWO_4, 13316 h with CdWO_4, and 13949 h with Gd_2SiO_5 crystals).

  20. The nuclear radius from alpha decay (*) Centre d'Etudes Nuclaires, Le Haut Vigneau, 33170 Gradignan, France

    E-Print Network [OSTI]

    Boyer, Edmond

    /3 law and they are consistent with the precise radii obtained from electron scattering. These two sets] have shown that the nuclear radius is not so simple and the law A 1/3 is only an approximation. The alpha decay radius. - We treat the case of the square well potential with a pure Coulomb potential

  1. Structure effects in the region of superheavy elements via the $\\alpha$-decay chain of $^{293}$118

    E-Print Network [OSTI]

    Gupta, Raj K; Kumar, Rajesh; Balasubramaniam, M; Scheid, W; 10.1088/0954-3899/28/11/310

    2011-01-01T23:59:59.000Z

    The $\\alpha$-decay chain of $^{293}$118, first proposed in the Berkeley cold fusion experiment $^{208}$Pb($^{86}$Kr,1n) and now retracted, is calculated by using the preformed cluster model (PCM) of one of us (RKG). Also, the possible branchings of $\\alpha$-particles to heavier cluster decays of all the parents in this chain are calculated for the first time. The calculated Q-values, penetrabilities and preformation factors for $\\alpha$-decays suggest that the $^{285}$114 nucleus with Z=114, N=171 is a magic nucleus, either due to the magicity of Z=114, or of N=172 or of both. The N=172 is proposed to be a magic number in certain relativistic mean-field calculations, but with Z=120. The calculated cluster decays point to new interesting possibilities of $^{14}$C decay of the $^{281}$112 parent, giving rise to a (reasonably) deformed Z=106, N=161, $^{267}$106 daughter (N=162 being now established as the deformed magic shell) or to a doubly magic $^{48}$Ca cluster emitted from any of the parent nucleus in the $...

  2. Millisecond Oxidation of Alkanes

    SciTech Connect (OSTI)

    Scott Han

    2011-09-30T23:59:59.000Z

    This project was undertaken in response to the Department of Energy's call to research and develop technologies 'that will reduce energy consumption, enhance economic competitiveness, and reduce environmental impacts of the domestic chemical industry.' The current technology at the time for producing 140 billion pounds per year of propylene from naphtha and Liquified Petroleum Gas (LPG) relied on energy- and capital-intensive steam crackers and Fluidized Catalytic Cracking (FCC) units. The propylene is isolated from the product stream in a costly separation step and subsequently converted to acrylic acid and other derivatives in separate production facilities. This project proposed a Short Contact Time Reactor (SCTR)-based catalytic oxydehydrogenation process that could convert propane to propylene and acrylic acid in a cost-effective and energy-efficient fashion. Full implementation of this technology could lead to sizeable energy, economic and environmental benefits for the U. S. chemical industry by providing up to 45 trillion BTUs/year, cost savings of $1.8 billion/year and a combined 35 million pounds/year reduction in environmental pollutants such as COx, NOx, and SOx. Midway through the project term, the program directive changed, which approval from the DOE and its review panel, from direct propane oxidation to acrylic acid at millisecond contact times to a two-step process for making acrylic acid from propane. The first step was the primary focus, namely the conversion of propane to propylene in high yields assisted by the presence of CO2. The product stream from step one was then to be fed directly into a commercially practiced propylene-to-acrylic acid tandem reactor system.

  3. HEP/123-qed Fine structure of alpha decay in odd nuclei

    E-Print Network [OSTI]

    M. Mirea

    2000-01-01T23:59:59.000Z

    Using an ? decay level scheme, the fine structure in odd nuclei is explained by taking into account the radial and rotational couplings between the unpaired valence nucleon and the core of the decaying system. It is shown that the experimental behavior of the ? decay fine structure phenomenon is governed by the dynamical characteristics of the system.

  4. Expected accuracy in a measurement of the CKM angle alpha using a Dalitz plot analysis of B0 ---> rho pi decays in the BTeV project

    SciTech Connect (OSTI)

    Shestermanov, K.E.; Vasiliev, A.N; /Serpukhov, IHEP; Butler, J.; Derevschikov, A.A.; Kasper, P.; Kiselev, V.V.; Kravtsov, V.I.; Kubota, Y.; Kutschke, R.; Matulenko, Y.A.; Minaev, N.G.; /Serpukhov, IHEP /Fermilab /Minnesota U. /Syracuse U. /INFN, Milan

    2005-12-01T23:59:59.000Z

    A precise measurement of the angle {alpha} in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract {alpha} is provided by B{sup 0} {yields} {rho}{pi} decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tre and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on {alpha} better than 5{sup o}.

  5. E-Print Network 3.0 - alpha-gamma decay studies Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with different experimental techniques. TECHNICAL... -free measurement of neutrinoless double-beta decay (0) in 120 kg of 76 Ge with the goal of determining the neutrino... mass....

  6. E-Print Network 3.0 - alpha-and beta-decay systematics Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fission and Nuclear Technologies ; Physics 2 What can we learn from neutrinoless double beta decay experiments? John N. Bahcall,* Hitoshi Murayama, + and C. Pen aGaray ...

  7. Constraint on the CKM angle $\\alpha$ from the experimental measurements of CP violation in $B_d^0 \\to \\pi^+ \\pi^-$ decay

    E-Print Network [OSTI]

    Lü, C D; L\\"u, Cai-Dian; Xiao, Zhenjun

    2002-01-01T23:59:59.000Z

    In this paper, we study and try to find the constraint on the CKM angle $\\alpha$ from the experimental measurements of CP violation in $B_d^0 \\to \\pi^+ \\pi^-$ decay, as reported very recently by BaBar and Belle Collaborations. After considering uncertainties of the data and the ratio $r$ of penguin over tree amplitude, we found that: (a) strong constraint on both the CKM angle $\\alpha$ and the strong phase $\\delta$ can be obtained from the measured $\\spp$, $A_{\\pi\\pi}$: only the ranges of $86^\\circ \\leq \\alpha \\leq 148^\\circ$ and $31^\\circ \\leq \\delta \\leq 143^\\circ$ are still allowed by $1\\sigma$ of the averaged data; (b) For Belle's result alone, the limit on $\\alpha$ is $95^\\circ \\leq \\alpha \\leq 152^\\circ$. The angle $\\alpha$ larger than $90^\\circ$ is strongly preferred.

  8. Color-singlet J/{psi} production at O({alpha}{sub s}{sup 6}) in {Upsilon} decay

    SciTech Connect (OSTI)

    He Zhiguo [Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918(4), Beijing, 100049 (China) and Theoretical Physics Center for Science Facilities, (CAS) Beijing, 100049 (China); Departament d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona Diagonal, 647, E-08028 Barcelona, Catalonia (Spain); Wang Jianxiong [Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918(4), Beijing, 100049 (China) and Theoretical Physics Center for Science Facilities, (CAS) Beijing, 100049 (China)

    2010-11-01T23:59:59.000Z

    To clarify the conflict between the theoretical predictions and experimental measurements of the inclusive J/{psi} production in {Upsilon} decay, we consider the {alpha}{sub s}{sup 6} order color-singlet (CS) contributions of processes {Upsilon}{yields}J/{psi}+gg and {Upsilon}{yields}J/{psi}+gggg. Both the branching ratio and the J/{psi} momentum spectrum are calculated, and the branching ratio (4.7x10{sup -4}) is larger than the leading-order contribution ({alpha}{sub s}{sup 5}, {Upsilon}{yields}J/{psi}+ccg). Together with the QCD and QED leading-order contributions considered in our previous work, the CS prediction of the branching ratio for the direct J/{psi} production is Br({Upsilon}{yields}J/{psi}{sub direct}+X)=0.90{sub -0.31}{sup +0.49}x10{sup -4}, which is still about 3.8 times less than the CLEO measurement. We also obtain a preliminary CS prediction of R{sub cc}=(B({Upsilon}{yields}J/{psi}+cc+X)/B({Upsilon}{yields}J/{psi}+X)) and find that the value 0.39{sub -0.20}{sup +0.21} is much larger than the color-octet prediction, and suggest to measure this quality in future experimental analysis.

  9. Cosmic-ray positrons from millisecond pulsars

    E-Print Network [OSTI]

    Venter, C; Harding, A K; Gonthier, P L; Büsching, I

    2015-01-01T23:59:59.000Z

    Observations by the Fermi Large Area Telescope of gamma-ray millisecond pulsar light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source of Galactic electrons and positrons, contributing to the observed enhancement in positron flux above ~10 GeV. Fermi has also uncovered many new millisecond pulsars, impacting Galactic stellar population models. We investigate the contribution of Galactic millisecond pulsars to the flux of terrestrial cosmic-ray electrons and positrons. Our population synthesis code predicts the source properties of present-day millisecond pulsars. We simulate their pair spectra invoking an offset-dipole magnetic field. We also consider positrons and electrons that have been further accelerated to energies of several TeV by strong intrabinary shocks in black widow and redback systems. Since millisecond pulsars are not surrounded by pulsar wind nebulae or supernova shells, we assume that the p...

  10. Accelerated alpha-decay of 232U isotope achieved by exposure of its aqueous solution with gold nanoparticles to laser radiation

    E-Print Network [OSTI]

    A. V. Simakin; G. A. Shafeev

    2011-12-29T23:59:59.000Z

    Experimental results are presented on laser-induced accelerated alpha-decay of Uranium-232 nuclei under laser exposure of Au nanoparticles in aqueous solutions of its salt. It is demonstrated that the decrease of alpha-activity strongly depends on the peak intensity of the laser radiation in the liquid and is highest at several terawatt per square centimeter. The decrease of alpha-activity of the exposed solutions is accompanied by the deviation of gamma-activities of daughter nuclides of Uranium-232 from their equilibrium values. Possible mechanisms of the laser influence on the alpha-activity are discussed on the basis of the amplification of the electric field of laser wave on metallic nanoparticles.

  11. Evolution from Canonical to Millisecond Pulsar through the X-ray Accretion Stage

    E-Print Network [OSTI]

    Norman K. Glendenning; Fridolin Weber

    2000-10-17T23:59:59.000Z

    We model the evolution of canonical pulsars from the death line to millisecond pulsars through the X-ray neutron star stage of accretion from a low-mass companion. We trace this evolution in magnetic field strength starting at $B=10^{12}$ to $10^8$ G and in period of about 1 s to milliseconds. Important factors are accretion rate and the decay rate of the magnetic field. A broad swathe is traced in the $B-P$ plane according to the value of these factors, which represent different conditions of the binary pair. An important ingredient is the dependence of the stellar moment of inertia on rotation frequency (time).

  12. Search for $\\alpha$ decay of $^{151}$Eu to the first excited level of $^{147}$Pm using underground $\\gamma$-ray spectrometry

    E-Print Network [OSTI]

    Danevich, F A; Hult, M; Marissens, G; Tretyak, V I; Yuksel, A; 10.1140/epja/i2012-12157-7

    2013-01-01T23:59:59.000Z

    The alpha decay of $^{151}$Eu to the first excited level of $^{147}$Pm ($J^\\pi = 5/2^+$, $E_{exc}=91.1$ keV) was searched for at the HADES underground laboratory ($\\approx 500$ m w.e.). A sample of high purity europium oxide with mass of 303 g and a natural isotopic composition has been measured over 2232.8 h with a high energy resolution ultra-low background n-type semi-planar HPGe detector (40 cm$^3$) with sub-micron deadlayer. The new improved half-life limit has been set as $T_{1/2} \\geq 3.7\\times 10^{18}$ yr at 68% C.L. Possibilities to improve the sensitivity of the experiment, which is already near the theoretical predictions, are discussed. New half-life limit for $\\alpha$ decay of $^{153}$Eu is also set as $T_{1/2} \\geq 5.5\\times 10^{17}$ yr.

  13. Modeling pulse profiles of accreting millisecond pulsars

    E-Print Network [OSTI]

    Juri Poutanen

    2008-09-14T23:59:59.000Z

    I review the basic observational properties of accreting millisecond pulsars that are important for understanding the physics involved in formation of their pulse profiles. I then discuss main effects responsible for shaping these profiles. Some analytical results that help to understand the results of simulations are presented. Constraints on the pulsar geometry and the neutron star equation of state obtained from the analysis of the pulse profiles are discussed.

  14. alpha iib beta: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 9 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  15. alpha trihydroxy-5 beta: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 7 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  16. alpha implication des: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XI, Universit de 3 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  17. alpha 2-macroglobulin implications: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    J Mol Obbard, Darren 6 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  18. alpha gross beta: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 14 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  19. alpha beta forms: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    R. Williamson 2005-04-04 14 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  20. Event counting alpha detector

    DOE Patents [OSTI]

    Bolton, R.D.; MacArthur, D.W.

    1996-08-27T23:59:59.000Z

    An electrostatic detector is disclosed for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure. 6 figs.

  1. Event counting alpha detector

    DOE Patents [OSTI]

    Bolton, Richard D. (Los Alamos, NM); MacArthur, Duncan W. (Los Alamos, NM)

    1996-01-01T23:59:59.000Z

    An electrostatic detector for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure.

  2. Measurement of Branching Fractions of B decays to K1(1270)pi and K1(1400)pi and Determination of the CKM angle alpha from B0 --> a1(1260) /- pi-/

    SciTech Connect (OSTI)

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2009-10-30T23:59:59.000Z

    We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K{sub 1}(1270) or K{sub 1}(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation. We measure the branching fractions {Beta}(B{sup 0} {yields} K{sub 1}(1270){sup +}{pi}{sup -} + K{sub 1}(1400){sup +}{pi}{sup -}) = 3.1{sub 0.7}{sup +0.8} x 10{sup -5} and {Beta}(B{sup +} {yields} K{sub 1}(1270){sup 0}{pi}{sup +} + K{sub 1}(1400){sup 0}{pi}{sup +}) = 2.9{sub -1.7}{sup +2.9} x 10{sup -5} (< 8.2 x 10{sup -5} at 90% confidence level), where the errors are statistical and systematic combined. The B{sup 0} decay mode is observed with a significance of 7.5{sigma}, while a significance of 3.2{sigma} is obtained for the B{sup +} decay mode. Based on these results, we estimate the weak phase {alpha} = (79 {+-} 7 {+-} 11){sup o} from the time dependent CP asymmetries in B{sup 0} {yields} a{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decays.

  3. E-Print Network 3.0 - alpha spectroscopy Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for Physics... semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes... , the number of known alpha emitters has been...

  4. E-Print Network 3.0 - alpha beta-gamma shielded Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sciences and Ecology 51 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Summary: Alpha Backgrounds and Their...

  5. E-Print Network 3.0 - alpha 6a continuous Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Information Sciences 68 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Summary: Alpha Backgrounds and Their...

  6. anti-tcr alpha beta: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 7 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  7. alpha 1-3gal beta: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 7 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  8. alpha beta t-cell: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yu. G. Zdesenko 2004-04-13 15 Alpha Backgrounds and Their Implications for Neutrinoless Double-Beta Decay Experiments Using HPGe Detectors Physics Websites Summary: Alpha...

  9. SPIN EVOLUTION OF MILLISECOND MAGNETARS WITH HYPERACCRETING FALLBACK DISKS: IMPLICATIONS FOR EARLY AFTERGLOWS OF GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Dai, Z. G.; Liu Ruoyu, E-mail: dzg@nju.edu.cn, E-mail: ryliu@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

    2012-11-01T23:59:59.000Z

    The shallow decay phase or plateau phase of early afterglows of gamma-ray bursts (GRBs), discovered by Swift, is currently understood as being due to energy injection to a relativistic blast wave. One natural scenario for energy injection invokes a millisecond magnetar as the central engine of GRBs because the conventional model of a pulsar predicts a nearly constant magnetic-dipole-radiation luminosity within the spin-down timescale. However, we note that significant brightening occurs in some early afterglows, which apparently conflicts with the above scenario. Here we propose a new model to explain this significant brightening phenomena by considering a hyperaccreting fallback disk around a newborn millisecond magnetar. We show that for typical values of the model parameters, sufficient angular momentum of the accreted matter is transferred to the magnetar and spins it up. It is this spin-up that leads to a dramatic increase of the magnetic-dipole-radiation luminosity with time and thus significant brightening of an early afterglow. Based on this model, we carry out numerical calculations and fit well early afterglows of 12 GRBs assuming sufficiently strong fallback accretion. If the accretion is very weak, our model turns out to be the conventional energy-injection scenario of a pulsar. Therefore, our model can provide a unified explanation for the shallow decay phase, plateaus, and significant brightening of early afterglows.

  10. Assessing Millisecond Proto-Magnetars as GRB Central Engines

    E-Print Network [OSTI]

    Todd A. Thompson

    2006-11-12T23:59:59.000Z

    Magnetars are a sizable subclass of the neutron star census. Their very high magnetic field strengths are thought to be a consequence of rapid (millisecond) rotation at birth in a successful core-collapse supernova. In their first tens of seconds of existence, magnetars transition from hot, extended ``proto-''magnetars to the cooled and magnetically-dominated objects we identify $\\sim10^4$ years later as Soft Gamma-ray Repeaters (SGRs) and Anamolous X-ray Pulsars (AXPs). Millisecond proto-magnetar winds during this cooling phase likewise transition from non-relativistic and thermally-driven to magneto-centrifugally-driven, and finally to relativistic and Poynting-flux dominated. Here we review the basic considerations associated with that transition. In particular, we discuss the spindown of millisecond proto-magnetars throughout the Kelvin-Helmholtz cooling epoch. Because of their large reservoir of rotational energy, their association with supernovae, and the fact that their winds are expected to become highly relativistic in the seconds after their birth, proto-magnetars have been suggested as the central engine of long-duration gamma ray bursts. We discuss some of the issues and outstanding questions in assessing them as such.

  11. Background canceling surface alpha detector

    DOE Patents [OSTI]

    MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

    1996-06-11T23:59:59.000Z

    A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs.

  12. Workshop on Precision Measurements of $\\alpha_s$

    SciTech Connect (OSTI)

    Bethke, Siegfried; /Munich, Max Planck Inst.; Hoang, Andre H.; /Vienna U.; Kluth, Stefan; /Munich, Max Planck Inst.; Schieck, Jochen; /Munich U.; Stewart, Iain W.; Aoki, S.; Beneke, M.; Bethke, S.; Blumlein, J.; Brambilla, N.; Brodsky, S.; /MIT, LNS

    2011-10-01T23:59:59.000Z

    These are the proceedings of the Workshop on Precision Measurements of {alpha}{sub s} held at the Max-Planck-Institute for Physics, Munich, February 9-11, 2011. The workshop explored in depth the determination of {alpha}{sub s}(m{sub Z}) in the {ovr MS} scheme from the key categories where high precision measurements are currently being made, including DIS and global PDF fits, {tau}-decays, electro-weak precision observables and Z-decays, event-shapes, and lattice QCD. These proceedings contain a short summary contribution from the speakers, as well as the lists of authors, conveners, participants, and talks.

  13. Green Bank Telescope Studies of Giant Pulses from Millisecond Pulsars

    E-Print Network [OSTI]

    H. S. Knight; M. Bailes; R. N. Manchester; S. M. Ord; B. A. Jacoby

    2005-12-13T23:59:59.000Z

    We have conducted a search for giant pulses from four millisecond pulsars using the 100m Green Bank Telescope. Coherently dedispersed time-series from PSR J0218+4232 were found to contain giant pulses of very short intrinsic duration whose energies follow power-law statistics. The giant pulses are in phase with the two minima of the radio integrated pulse profile but are phase aligned with the peaks of the X-ray profile. Historically, individual pulses more than 10-20 times the mean pulse energy have been deemed to be ``giant pulses''. As only 4 of the 155 pulses had energies greater than 10 times the mean pulse-energy, we argue the emission mechanism responsible for giant pulses should instead be defined through: (a) intrinsic timescales of microsecond or nanosecond duration; (b) power-law energy statistics; and (c) emission occurring in narrow phase-windows coincident with the phase windows of non-thermal X-ray emission. Four short-duration pulses with giant-pulse characteristics were also observed from PSR B1957+20. As the inferred magnetic fields at the light cylinders of the millisecond pulsars that emit giant pulses are all very high, this parameter has previously been considered to be an indicator of giant pulse emissivity. However, the frequency of giant pulse emission from PSR~B1957+20 is significantly lower than for other millisecond pulsars that have similar magnetic fields at their light cylinders. This suggests that the inferred magnetic field at the light cylinder is a poor indicator of the rate of emission of giant pulses.

  14. Far-Infrared ISO Limits on Dust Disks around Millisecond Pulsars

    E-Print Network [OSTI]

    T. J. W. Lazio; J. Fischer; R. S. Foster

    2001-09-26T23:59:59.000Z

    We report 60 and 90 micron observations of 7 millisecond pulsars with the ISOPHOT instrument and describe our analysis procedures. No pulsars were detected, and typical (3\\sigma) upper limits are 150 mJy. We combine our results with others in the literature and use them to place constraints on the existence of protoplanetary or dust disks around millisecond pulsars.

  15. Millisecond pulsar population in the Galactic center and high energy contributions

    E-Print Network [OSTI]

    W. Wang

    2005-10-15T23:59:59.000Z

    We propose that there possibly exists a population of millisecond pulsars in the Galactic center region. Millisecond pulsars (MSPs) could emit GeV gamma-rays through synchrotron-curvature radiation as predicted by outer gap models. In the same time, the compact wind nebulae around millisecond pulsars can emit X-rays though synchrotron radiation and TeV photons through inverse Compton processes. Besides, millisecond pulsar winds provide good candidates for the electron-positrons sources in the Galactic center. Therefore, we suggest that the millisecond pulsar population could contribute to the weak unidentified Chandra X-ray sources, the diffuse gamma-rays detected by EGRET, electron-positron annihilation lines and TeV photons detected by HESS toward the Galactic center.

  16. The Millisecond Magnetar Central Engine in short GRBs

    E-Print Network [OSTI]

    Lü, Hou-Jun; Lei, Wei-Hua; Li, Ye; Lasky, Paul D

    2015-01-01T23:59:59.000Z

    One favored progenitor model for short duration gamma-ray bursts (SGRBs) is the coalescence of two neutron stars (NS-NS). One possible outcome of such a merger would be a rapidly spinning, strongly magnetized neutron star (known as a millisecond magnetar). These magnetars may be "supra-massive", implying they would collapse to black holes after losing centrifugal support due to magnetic dipole spindown. By systematically analyzing the BAT-XRT light curves of all short GRBs detected by {\\em swift}, we test how well the data are consistent with this central engine model of short GRBs. We find that the so-called "extended emission" observed with BAT in some short GRBs are fundamentally the same component as the "internal X-ray plateau" as observed in many short GRBs, which is defined as a plateau in the lightcurve followed by a very rapid drop. Based on how likely a short GRB hosts a magnetar, we characterize the entire {\\em Swift} short GRB sample into three categories: the "internal plateau" sample, the "exter...

  17. Helium-cluster decay widths of molecular states in beryllium and carbon isotopes

    E-Print Network [OSTI]

    J. C. Pei; F. R. Xu

    2007-02-01T23:59:59.000Z

    The $\\alpha$ particle and $^6$He emissions from possible molecular states in beryllium and carbon isotopes have been studied using a mean-field-type cluster potential. Calculations can reproduce well the $\\alpha$-decay widths of excited states in $^{8}$Be, $^{12}$C and $^{20}$Ne. For the nucleus $^{10}$Be, we discussed the $\\alpha$-decay widths with different shapes or decay modes, in order to understand the very different decay widths of two excited states. The widths of $^{6}$He decay from $^{12}$Be and $\\alpha$ decays from $^{13,14}$C are predicted, which could be useful for future experiments.

  18. Lunar surface outgassing and alpha particle measurements

    SciTech Connect (OSTI)

    Lawson, S. L. (Stefanie L.); Feldman, W. C. (William C.); Lawrence, David J. (David Jeffery),; Moore, K. R. (Kurt R.); Elphic, R. C. (Richard C.); Maurice, S. (Sylvestre); Belian, Richard D.; Binder, Alan B.

    2002-01-01T23:59:59.000Z

    The Lunar Prospector Alpha Particle Spectrometer (LP APS) searched for lunar surface gas release events and mapped their distribution by detecting alpha particle?; produced by the decay of gaseous radon-222 (5.5 MeV, 3.8 day half-life), solid polonium-2 18 (6.0 MeV, 3 minute half-life), and solid polonium-210 (5.3 MeV, 138 day half-life, but held up in production by the 21 year half-life of lead-210). These three nuclides are radioactive daughters from the decay of uranium-238.

  19. DETECTION AND FLUX DENSITY MEASUREMENTS OF THE MILLISECOND PULSAR J2145–0750 BELOW 100 MHz

    SciTech Connect (OSTI)

    Dowell, J.; Taylor, G. B.; Craig, J.; Henning, P. A.; Schinzel, F. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)] [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Ray, P. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)] [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Blythe, J. N. [School of Physics, Georgia Institute of Technology, Atlanta, GA 3033 (United States)] [School of Physics, Georgia Institute of Technology, Atlanta, GA 3033 (United States); Clarke, T.; Helmboldt, J. F. [U.S. Naval Research Laboratory, Washington, DC 20375 (United States)] [U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Ellingson, S. W.; Wolfe, C. N. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA 24061 (United States); Lazio, T. J. W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Stovall, K., E-mail: jdowell@unm.edu [Center for Gravitational Wave Astronomy and Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States)

    2013-09-20T23:59:59.000Z

    We present flux density measurements and pulse profiles for the millisecond pulsar PSR J2145–0750 spanning 37 to 81 MHz using data obtained from the first station of the Long Wavelength Array. These measurements represent the lowest frequency detection of pulsed emission from a millisecond pulsar to date. We find that the pulse profile is similar to that observed at 102 MHz. We also find that the flux density spectrum between ?40 MHz to 5 GHz is suggestive of a break and may be better fit by a model that includes spectral curvature with a rollover around 730 MHz rather than a single power law.

  20. Nuclear-Powered Millisecond Pulsars and the Maximum Spin Frequency of Neutron Stars

    E-Print Network [OSTI]

    Deepto Chakrabarty; Edward H. Morgan; Michael P. Muno; Duncan K. Galloway; Rudy Wijnands; Michiel van der Klis; Craig B. Markwardt

    2003-07-01T23:59:59.000Z

    Millisecond pulsars are neutron stars (NSs) that are thought to have been spun-up by mass accretion from a stellar companion. It is unknown whether there is a natural brake for this process, or if it continues until the centrifugal breakup limit is reached at submillisecond periods. Many NSs that are accreting from a companion exhibit thermonuclear X-ray bursts that last tens of seconds, caused by unstable nuclear burning on their surfaces. Millisecond brightness oscillations during bursts from ten NSs (as distinct from other rapid X-ray variability that is also observed) are thought to measure the stellar spin, but direct proof of a rotational origin has been lacking. Here, we report the detection of burst oscillations at the known spin frequency of an accreting millisecond pulsar, and we show that these oscillations always have the same rotational phase. This firmly establishes burst oscillations as nuclear-powered pulsations tracing the spin of accreting NSs, corroborating earlier evidence. The distribution of spin frequencies of the 11 nuclear-powered pulsars cuts off well below the breakup frequency for most NS models, supporting theoretical predictions that gravitational radiation losses can limit accretion torques in spinning up millisecond pulsars.

  1. Millisecond switching in solid state electrochromic polymer devices fabricated from ionic self-assembled multilayers

    E-Print Network [OSTI]

    Heflin, Randy

    Millisecond switching in solid state electrochromic polymer devices fabricated from ionic self The electrochromic switching times of solid state conducting polymer devices fabricated by the ionic self shown to decrease with the active area of the electrochromic device suggesting that even faster

  2. Swinging between rotation and accretion power in a millisecond binary pulsar

    E-Print Network [OSTI]

    Papitto, A; Bozzo, E; Rea, N; Pavan, L; Campana, S; Romano, P; Burderi, L; Di Salvo, T; Riggio, A; Torres, D F; Falanga, M; Hessels, J W T; Burgay, M; Sarkissian, J M; Wieringa, M H; Filipovi?, M D; Wong, G F

    2013-01-01T23:59:59.000Z

    Radio pulsars are neutron stars that emit radiation modulated and powered by the rotation of their magnetic field, and which consequently decelerate (Pacini, 1967). The very fast millisecond spin periods measured in old radio pulsars (Backer et al. 1982) are thought to be the outcome of an earlier X-ray bright phase, during which the neutron star accretes matter and angular momentum from a low mass companion star in a binary system (Alpar et al. 1982; Radhakrishnan & Srinivasan 1982). This evolutionary scenario has been supported by the detection of X-ray millisecond pulsations from several accreting neutron stars in the past fifteen years (Wijnands & van der Klis 1998), as well as by the indirect evidence for the presence of a disk in the past around a millisecond radio pulsar now powered by rotation (Archibald et al. 2009). However, a transition between a rotation-powered and an accretion-powered state was never observed. Here we present the detection of millisecond X-ray pulsations from an accretin...

  3. Ab initio alpha-alpha scattering

    E-Print Network [OSTI]

    Serdar Elhatisari; Dean Lee; Gautam Rupak; Evgeny Epelbaum; Hermann Krebs; Timo A. Lähde; Thomas Luu; Ulf-G. Meißner

    2015-06-11T23:59:59.000Z

    Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.

  4. Ab initio alpha-alpha scattering

    E-Print Network [OSTI]

    Elhatisari, Serdar; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-01-01T23:59:59.000Z

    Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.

  5. Time-resolved temperature measurement and numerical simulation of millisecond laser irradiated silicon

    SciTech Connect (OSTI)

    Li Zewen; Zhang Hongchao; Shen Zhonghua; Ni Xiaowu [School of Science, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2013-07-21T23:59:59.000Z

    Thermal process of 1064 nm millisecond pulsed Nd:YAG laser irradiated silicon was time-resolved temperature measured by an infrared radiation pyrometer, temperature evolutions of the spot center for wide range of laser energy densities were presented. The waveforms of temperature evolution curves contained much information about phase change, melting, solidification and vaporization. An axisymmetric numerical model was established for millisecond laser heating silicon. The transient temperature fields were obtained by using the finite element method. The numerical results of temperature evolutions of the spot center are in good agreement with the experimental results. Furthermore, the axial temperature distributions of the numerical results give a better understanding of the waveforms in the experimental results. The melting threshold, vaporizing threshold, melting duration, and melting depth were better identified by analyzing two kinds of results.

  6. A Tighter Constraint on post-Newtonian Gravity using Millisecond Pulsars

    E-Print Network [OSTI]

    J. F. Bell

    1995-08-08T23:59:59.000Z

    Some theories of gravity predict the existence of preferred-frame effects and violations of conservation of energy and momentum. General relativity predicts no such effects. In the parameterised post-Newtonian (PPN) formalism, the parameter, \\al3 $\\equiv 0$ if these effects do not exist. The period derivatives ($\\dot{P}$) of millisecond pulsars (MSPs) are used to more tightly constrain these effects by showing that $|$\\al3$|$ $< 5 \\times 10^{-16}$.

  7. Temporal variations in space-time and progenitors of gamma ray burst and millisecond pulsars

    E-Print Network [OSTI]

    Preston Jones

    2007-08-31T23:59:59.000Z

    A time varying space-time metric is shown to be a source of electromagnetic radiation. The post-Newtonian approximation is used as a realistic model of the connection between the space-time metric and a time varying gravitational potential. Large temporal variations in the metric from the coalescence of colliding black holes and neutron stars are shown to be possible progenitors of gamma ray burst and millisecond pulsars.

  8. The beta-decay of 22Al

    E-Print Network [OSTI]

    N. L. Achouri; F. de Oliveira Santos; M. Lewitowicz; B. Blank; J. Aysto; G. Canchel; S. Czajkowski; P. Dendooven; A. Emsallem; J. Giovinazzo; N. Guillet; A. Jokinen; A. M. Laird; C. Longour; K. Perajarvi; N. Smirnova; M. Stanoiu; J. C. Thomas

    2006-08-01T23:59:59.000Z

    In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22Al.

  9. Light curves and polarization of accretion- and nuclear-powered millisecond pulsars

    E-Print Network [OSTI]

    Kerttu Viironen; Juri Poutanen

    2004-08-13T23:59:59.000Z

    We study theoretical X-ray light curves and polarization properties of accretion-powered millisecond pulsars. We assume that the radiation is produced in two antipodal spots at the neutron star surface which are associated with the magnetic poles. We compute the angle-dependent intensity and polarization produced in an electron-scattering dominated plane-parallel accretion shock in the frame of the shock. The observed flux, polarization degree and polarization angle are calculated accounting for special and general relativistic effects. The calculations also extended to the case of nuclear-powered millisecond pulsars -- X-ray bursts. In this case, we consider one spot and the radiation is assumed to be produced in the atmosphere of the infinite Thomson optical depth. The light curves and polarization profiles show a large diversity depending on the model parameters. Presented results can be used as a first step to understand the observed pulse profiles of accretion- and nuclear-powered millisecond pulsars. Future observations of the X-ray polarization will provide a valuable tool to test the geometry of the emission region and its physical characteristics.

  10. Millisecond Kinetics of Nanocrystal Cation Exchange UsingMicrofluidic X-ray Absorption Spectroscopy

    SciTech Connect (OSTI)

    Chan, Emory M.; Marcus, Matthew A.; Fakra, Sirine; Elnaggar,Mariam S.; Mathies, Richard A.; Alivisatos, A. Paul

    2007-05-07T23:59:59.000Z

    We describe the use of a flow-focusing microfluidic reactorto measure the kinetics of theCdSe-to-Ag2Se nanocrystal cation exchangereaction using micro-X-ray absorption spectroscopy (mu XAS). The smallmicroreactor dimensions facilitate the millisecond mixing of CdSenanocrystal and Ag+ reactant solutions, and the transposition of thereaction time onto spatial coordinates enables the in situ observation ofthe millisecond reaction with mu XAS. XAS spectra show the progression ofCdSe nanocrystals to Ag2Se over the course of 100 ms without the presenceof long-lived intermediates. These results, along with supporting stoppedflow absorption experiments, suggest that this nanocrystal cationexchange reaction is highly efficient and provide insight into how thereaction progresses in individual particles. This experiment illustratesthe value and potential of in situ microfluidic X-ray synchrotrontechniques for detailed studies of the millisecond structuraltransformations of nanoparticles and other solution-phase reactions inwhich diffusive mixing initiates changes in local bond structures oroxidation states.

  11. ?-Decay in Ultra-Intense Laser Fields

    E-Print Network [OSTI]

    Serban Misicu; Margarit Rizea

    2013-07-05T23:59:59.000Z

    We investigate the \\alpha-decay of a spherical nucleus under the influence of an ultra-intense laser field for the case when the radius vector joining the center-of-masses of the \\alpha-particle and the daughter is aligned with the direction of the external field. The time-independent part of the \\alpha-daughter interaction is taken from elastic scattering compilations whereas the time-varying part describes the interaction between the decaying system with the laser field. The time-dependent Schr\\"odinger equation is solved numerically by appealing to a modified scheme of the Crank-Nicolson type where an additional first-order time derivative appears compared to the field-free case. The tunneling probability of the \\alpha-cluster, and derived quantities (decay rate, total flux) is determined for various laser intensities and frequencies for either continous waves or few-cycle pulses of envelope function F(t)=1. We show that in the latter case pulse sequences containing an odd number of half-cycles determine an enhancement of the tunneling probability compared to the field-free case and the continuous wave case. The present study is carried out taking as example the alpha decaying nucleus $^{106}$Te.

  12. Apparatus for detecting alpha radiation in difficult access areas

    DOE Patents [OSTI]

    Steadman, Peter (Santa Fe, NM); MacArthur, Duncan W. (Los Alamos, NM)

    1997-09-02T23:59:59.000Z

    An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure.

  13. Apparatus for detecting alpha radiation in difficult access areas

    DOE Patents [OSTI]

    Steadman, P.; MacArthur, D.W.

    1997-09-02T23:59:59.000Z

    An electrostatic alpha radiation detector for measuring alpha radiation emitted from inside an enclosure comprising an electrically conductive expandable electrode for insertion into the enclosure is disclosed. After insertion, the electrically conductive expandable electrode is insulated from the enclosure and defines a decay cavity between the electrically conductive expandable electrode and the enclosure so that air ions generated in the decay cavity are electrostatically captured by the electrically conductive expandable electrode and the enclosure when an electric potential is applied between the electrically conductive expandable electrode and the enclosure. Indicator means are attached to the electrically conductive expandable electrode for indicating an electrical current produced by generation of the air ions generated in the decay cavity by collisions between air molecules and the alpha particles emitted from the enclosure. A voltage source is connected between the indicator means and the electrically conductive enclosure for creating an electric field between the electrically conductive expandable electrode and the enclosure. 4 figs.

  14. Nuclear diagnostic for fast alpha particles

    DOE Patents [OSTI]

    Grisham, Larry R. (Lawrence Township, Mercer County, NJ); Post, Jr., Douglass E. (Belle Mead, NJ); Dawson, John M. (Pacific Palisades, CA)

    1986-01-01T23:59:59.000Z

    Measurement of the velocity distribution of confined energetic alpha particles resulting from deuterium-tritium fusion reactions in a magnetically contained plasma is provided. The fusion plasma is seeded with energetic boron neutrals for producing, by means of the reaction .sup.10 B (.alpha.,n) .sup.13 N reaction, radioactive nitrogen nuclei which are then collected by a probe. The radioactivity of the probe is then measured by conventional techniques in determining the energy distribution of the alpha particles in the plasma. In a preferred embodiment, diborane gas (B.sub.2 H.sub.6) is the source of the boron neutrals to produce .sup.13 N which decays almost exclusively by positron emission with a convenient half-life of 10 minutes.

  15. Evaporation of alpha particles from $^31$P nucleus

    E-Print Network [OSTI]

    D. Bandyopadhyay; S. K. Basu; C. Bhattacharya; S. Bhattacharya; K. Krishan; A. Chatterjee; S. Kailas; A. Navin; A. Srivastava

    1998-07-24T23:59:59.000Z

    The energy spectra of alpha particles have been measured in coincidence with the evaporation residues for the decay of the compound nucleus $^31$P produced in the reaction $^19$F (96 MeV) + $^12$C. The data have been compared with the predictions of the statistical model code CASCADE. It has been observed that significant deformation effect in the compound nucleus need to be considered in order to explain the shape of the evaporated alpha particle energy spectra.

  16. What the Timing of Millisecond Pulsars Can Teach us about Their Interior

    E-Print Network [OSTI]

    Mark G. Alford; Kai Schwenzer

    2014-12-08T23:59:59.000Z

    The cores of compact stars reach the highest densities in nature and therefore could consist of novel phases of matter. We demonstrate via a detailed analysis of pulsar evolution that precise pulsar timing data can constrain the star's composition, through unstable global oscillations (r-modes) whose damping is determined by microscopic properties of the interior. If not efficiently damped, these modes emit gravitational waves that quickly spin down a millisecond pulsar. As a first application of this general method, we find that ungapped interacting quark matter is consistent with both the observed radio and x-ray data, whereas for ordinary nuclear matter some additional enhanced damping mechanism is required.

  17. Laser-induced damage threshold of silicon in millisecond, nanosecond, and picosecond regimes

    SciTech Connect (OSTI)

    Wang, X.; Shen, Z. H.; Lu, J.; Ni, X. W. [School of Science, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2010-08-15T23:59:59.000Z

    Millisecond, nanosecond, and picosecond laser pulse induced damage thresholds on single-crystal are investigated in this study. The thresholds of laser-induced damage on silicon are calculated theoretically for three pulse widths based on the thermal damage model. An axisymmetric mathematical model is established for the transient temperature field of the silicon. Experiments are performed to test the damage thresholds of silicon at various pulse widths. The results indicate that the damage thresholds obviously increase with the increasing of laser pulse width. Additionally, the experimental results agree well with theoretical calculations and numerical simulation results.

  18. An alpha scintillation spectrometer

    E-Print Network [OSTI]

    Yates, Ralph Aaron

    1952-01-01T23:59:59.000Z

    phosphor covered light-piper. The ten different energy alpha particles that were emitted from the Uranium were blended into a continuous distribution, there being no apparent difference between this and the thick Thorium distribution. The same was true... investi- gation of the properties of alpha radiation. In his work, the scin- tillations produced by alpha particles impinging on a zinc-sulphide screen were observed and counted visually with the aid of a low power microscope. The scintillations...

  19. Numerical and experimental study of the thermal stress of silicon induced by a millisecond laser

    SciTech Connect (OSTI)

    Wang Xi; Qin Yuan; Wang Bin; Zhang Liang; Shen Zhonghua; Lu Jian; Ni Xiaowu

    2011-07-20T23:59:59.000Z

    A spatial axisymmetric finite element model of single-crystal silicon irradiated by a 1064 nm millisecond laser is used to investigate the thermal stress damage induced by a millisecond laser. The transient temperature field and the thermal stress field for 2 ms laser irradiation with a laser fluence of 254 J/cm{sup 2} are obtained. The numerical simulation results indicate that the hoop stresses along the r axis on the front surface are compressive stress within the laser spot and convert to tensile stress outside the laser spot, while the radial stresses along the r axis on the front surface and on the z axis are compressive stress. The temperature of the irradiated center is the highest temperature obtained, yet the stress is not always highest during laser irradiation. At the end of the laser irradiation, the maximal hoop stress is located at r=0.5 mm and the maximal radial stress is located at r=0.76 mm. The temperature measurement experiments are performed by IR pyrometer. The numerical result of the temperature field is consistent with the experimental result. The damage morphologies of silicon under the action of a 254 J/cm{sup 2} laser are inspected by optical microscope. The cracks are observed initiating at r=0.5 mm and extending along the radial direction.

  20. The X-ray afterglow flat segment in short GRB 051221A: Energy injection from a millisecond magnetar?

    E-Print Network [OSTI]

    Yizhong Fan; Dong Xu

    2006-07-12T23:59:59.000Z

    The flat segment lasting $\\sim 10^4$ seconds in the X-ray afterglow of GRB051221A represents the first clear case of strong energy injection in the external shock of a short GRB afterglow. In this work, we show that a millisecond pulsar with dipole magnetic field $\\sim 10^{14}$ Gauss could well account for that energy injection. The good quality X-ray flat segment thus suggests that the central engine of this short burst may be a millisecond magnetar.

  1. alpha cap alpha: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  2. alpha pkc alpha: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  3. Comment on "15O(alpha,gamma)19Ne Breakout Reaction and Impact on X-Ray Bursts"

    E-Print Network [OSTI]

    B. Davids

    2008-04-12T23:59:59.000Z

    A recently published letter reports a measurement of alpha decay from states in 19Ne at excitation energies below 4.5 MeV. The measured alpha decay branching ratios B_alpha are used to calculate the astrophysical rate of the 15O(alpha,gamma)19Ne reaction and to draw conclusions regarding the transition between steady state and unstable nuclear burning on accreting neutron stars. Here I show that the calculated astrophysical reaction rate is based on an unreliable value of B_alpha for the 4.03 MeV state and point out a serious internal inconsistency in the letter's treatment of low statistics alpha decay measurements.

  4. A propeller model for the sub-luminous disk state of the transitional millisecond pulsar PSR J1023+0038

    E-Print Network [OSTI]

    Papitto, A

    2015-01-01T23:59:59.000Z

    The discovery of millisecond pulsars switching between states powered either by the rotation of their magnetic field or by the accretion of matter, has recently proved the tight link shared by millisecond radio pulsars and neutron stars in low-mass X-ray binaries. Transitional millisecond pulsars also show an enigmatic intermediate state in which the neutron star is surrounded by an accretion disk, it emits coherent X-ray pulsations, but is sub-luminous in X-rays with respect to accreting neutron stars, and is brighter in gamma-rays than millisecond pulsars in the rotation-powered state. Here, we model the X-ray and gamma-ray emission observed from PSR J1023+0038 in such a state based on the assumption that most of the disk in-flow is propelled away by the rapidly rotating neutron star magnetosphere, and that electrons can be accelerated to energies of a few GeV at the turbulent disk-magnetosphere boundary. We show that the synchrotron and self-synchrotron Compton emission coming from such a region, together ...

  5. Excitation of a nonradial mode in a millisecond X-ray pulsar XTE J1751-305

    E-Print Network [OSTI]

    Lee, Umin

    2014-01-01T23:59:59.000Z

    We discuss candidates for non-radial modes excited in a mass accreting and rapidly rotating neutron star to explain the coherent frequency identified in the light curves of a millisecond X-ray pulsar XTE J1751-305. The spin frequency of the pulsar is $\

  6. Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized for in situ applications

    E-Print Network [OSTI]

    Sparks, Donald L.

    Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized of quick extended x-ray absorption fine structure QEXAFS and quick x-ray absorption near edge structure- tion spectroscopy XAS was developed in energy dispersive and quick extended x-ray absorption fine

  7. Automatically processed alpha-track radon monitor

    DOE Patents [OSTI]

    Langner, G.H. Jr.

    1993-01-12T23:59:59.000Z

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  8. Bremsstrahlung emission during $?$-decay of $^{226}{\\rm Ra}$

    E-Print Network [OSTI]

    Giorgio Giardina; Giovanni Fazio; Giuseppe Mandaglio; Marina Manganaro; Serghei P. Maydanyuk; Vladislav S. Olkhovsky; Nikolay V. Eremin; Anton A. Paskhalov; Dmitry A. Smirnov; Carmelo Sacca

    2008-04-16T23:59:59.000Z

    We obtained the spectrum of probability of the bremsstrahlung emission accompanying the $\\alpha$-decay of $^{226}{\\rm Ra}$ (E$_{\\alpha}$=4.8 MeV) by measuring the $\\alpha$-$\\gamma$ coincidences and using the model presented in our previous study on the $\\alpha-$decay of $^{214}{\\rm Po}$ (E$_{\\alpha}$=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the $\\alpha$-decay of the $^{226}{\\rm Ra}$ and $^{214}{\\rm Po}$ nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the $\\alpha$-particle gives an important contribution to the bremsstrahlung spectrum in the whole E$_{\\gamma}$ energy range of the studied $^{226}$Ra nucleus.

  9. Exploring the intrabinary shock from the redback millisecond pulsar PSR J2129-0429

    E-Print Network [OSTI]

    Hui, C Y; Park, S M; Takata, J; Li, K L; Tam, P H T; Lin, L C C; Kong, A K H; Cheng, K S; Kim, Chunglee

    2015-01-01T23:59:59.000Z

    We have investigated the intrabinary shock emission from the redback millisecond pulsar PSR J2129-0429 with XMM-Newton and Fermi. Orbital modulation in X-ray and UV can be clearly seen. Its X-ray modulation has a double-peak structure with a dip in between. The observed X-rays are non-thermal dominant which can be modeled by a power-law with a photon index of ~1.2. Intrabinary shock can be the origin of the observed X-rays. The UV light curve is resulted from the ellipsoidal modulation of the companion. Modeling the UV light curve prefers a large viewing angle. The heating effect of the UV light curve is found to be negligible which suggests the high energy radiation beam of PSR J2129-0429 does not direct toward its companion. On the other hand, no significant orbital modulation can be found in gamma-ray which suggests the majority of the gamma-rays come from the pulsar.

  10. RADIO DETECTION OF THE FERMI-LAT BLIND SEARCH MILLISECOND PULSAR J1311-3430

    SciTech Connect (OSTI)

    Ray, P. S.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Cheung, C. C. [National Academy of Sciences, Washington, DC 20001 (United States); Giroletti, M. [INAF Istituto di Radioastronomia, I-40129 Bologna (Italy); Cognard, I. [Laboratoire de Physique et Chimie de l'Environnement, LPCE UMR 6115 CNRS, F-45071 Orleans Cedex 02 (France); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Bhattacharyya, B. [Inter-University Centre for Astronomy and Astrophysics, Pune 411 007 (India); Roy, J. [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune 411 007 (India); Romani, R. W.; Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ferrara, E. C. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Johnston, S.; Keith, M. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping NSW 1710 (Australia); Pletsch, H. J. [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, D-30167 Hannover (Germany); Saz Parkinson, P. M., E-mail: Paul.Ray@nrl.navy.mil [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States)

    2013-01-20T23:59:59.000Z

    We report the detection of radio emission from PSR J1311-3430, the first millisecond pulsar (MSP) discovered in a blind search of Fermi Large Area Telescope (LAT) gamma-ray data. We detected radio pulsations at 2 GHz, visible for <10% of {approx}4.5 hr of observations using the Green Bank Telescope (GBT). Observations at 5 GHz with the GBT and at several lower frequencies with Parkes, Nancay, and the Giant Metrewave Radio Telescope resulted in non-detections. We also report the faint detection of a steep spectrum continuum radio source (0.1 mJy at 5 GHz) in interferometric imaging observations with the Jansky Very Large Array. These detections demonstrate that PSR J1311-3430 is not radio quiet and provide additional evidence that radio-quiet MSPs are rare. The radio dispersion measure of 37.8 pc cm{sup -3} provides a distance estimate of 1.4 kpc for the system, yielding a gamma-ray efficiency of 30%, typical of LAT-detected MSPs. We see apparent excess delay in the radio pulses as the pulsar appears from eclipse and we speculate on possible mechanisms for the non-detections of the pulse at other orbital phases and observing frequencies.

  11. Lighthouses with two lights: burst oscillations from the accretion-powered millisecond pulsars

    E-Print Network [OSTI]

    Anna L. Watts

    2008-08-19T23:59:59.000Z

    The key contribution of the discovery of nuclear-powered pulsations from the accretion-powered millisecond pulsars (AMPs) has been the establishment of burst oscillation frequency as a reliable proxy for stellar spin rate. This has doubled the sample of rapidly-rotating accreting neutron stars and revealed the unexpected absence of any stars rotating near the break-up limit. The resulting `braking problem' is now a major concern for theorists, particularly given the possible role of gravitational wave emission in limiting spin. This, however, is not the only area where burst oscillations from the AMPs are having an impact. Burst oscillation timing is developing into a promising technique for verifying the level of spin variability in the AMPs (a topic of considerable debate). These sources also provide unique input to our efforts to understand the still-elusive burst oscillation mechanism. This is because they are the only stars where we can reliably gauge the role of uneven fuel deposition and, of course, the magnetic field.

  12. Magnetic burial and the harmonic content of millisecond oscillations in thermonuclear X-ray bursts

    E-Print Network [OSTI]

    D. J. B. Payne; A. Melatos

    2006-07-11T23:59:59.000Z

    Matter accreting onto the magnetic poles of a neutron star spreads under gravity towards the magnetic equator, burying the polar magnetic field and compressing it into a narrow equatorial belt. Steady-state, Grad-Shafranov calculations with a self-consistent mass-flux distribution (and a semi-quantitative treatment of Ohmic diffusion) show that, for $\\Ma \\gtrsim 10^{-5}\\Msun$, the maximum field strength and latitudinal half-width of the equatorial magnetic belt are $B_{\\rm max} = 5.6\\times 10^{15} (\\Ma/10^{-4}\\Msun)^{0.32}$ G and $\\Delta\\theta = \\max[3^{\\circ} (\\Ma/10^{-4}\\Msun)^{-1.5},3^{\\circ} (\\Ma/10^{-4}\\Msun)^{0.5}(\\dot{M}_{\\rm a}/10^{-8}\\Msun {\\rm yr}^{-1})^{-0.5}]$ respectively, where $\\Ma$ is the total accreted mass and $\\dot{M}_{\\rm a}$ is the accretion rate. It is shown that the belt prevents north-south heat transport by conduction, convection, radiation, and ageostrophic shear. This may explain why millisecond oscillations observed in the tails of thermonuclear (type I) X-ray bursts in low-mass X-ray binaries are highly sinusoidal: the thermonuclear flame is sequestered in the magnetic hemisphere which ignites first. The model is also consistent with the occasional occurrence of closely spaced pairs of bursts. Time-dependent, ideal-magnetohydrodynamic simulations confirm that the equatorial belt is not disrupted by Parker and interchange instabilities.

  13. Cluster-model calculations of exotic decays from heavy nuclei

    SciTech Connect (OSTI)

    Buck, B.; Merchant, A.C.

    1989-05-01T23:59:59.000Z

    A cluster model employing a local, effective cluster-core potential is used to investigate exotic decay from heavy nuclei as a quantum tunneling phenomenon within a semiclassical approximation. Excellent agreement with all reported experimental measurements of the decay widths for /sup 14/C and /sup 24/Ne emission is obtained. As an added bonus, the width for alpha particle emission from /sup 212/Po is also calculated in good agreement with experiment.

  14. QCD Studies and alpha_s Measurements at LEP

    E-Print Network [OSTI]

    Stefan Soldner-Rembold

    2004-11-01T23:59:59.000Z

    The LEP experiments have measured event shapes using data taken at e+e- center-of-mass energies ranging from 91 GeV to 209 GeV. Using the final LEP event shape measurements, a combined value of the strong coupling constant alpha_s(M_Z) has been extracted. Events with photon radiation have been used to extend the measurements to lower center-of-mass energies sqrt(s') to study the running of alpha_s. Alternative alpha_s measurements using four-jet rates have also been performed.

  15. PSR J1723–2837: AN ECLIPSING BINARY RADIO MILLISECOND PULSAR

    SciTech Connect (OSTI)

    Crawford, Fronefield [Department of Physics and Astronomy, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17604 (United States); Lyne, Andrew G. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom); Stairs, Ingrid H. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Kaplan, David L. [Physics Department, University of Wisconsin - Milwaukee, Milwaukee, WI 53211 (United States); McLaughlin, Maura A.; Lorimer, Duncan R. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Freire, Paulo C. C.; Kramer, Michael [Max-Planck-Institut für Radioastronomie, auf dem Huegel 69, D-53121 Bonn (Germany); Burgay, Marta; D'Amico, Nichi; Possenti, Andrea [INAF - Osservatorio Astronomico di Cagliari, Poggio dei Pini, I-09012 Capoterra (Italy); Camilo, Fernando [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Faulkner, Andrew [Cavendish Laboratory, University of Cambridge, J. J. Thompson Avenue, Cambridge, CB3 0HE (United Kingdom); Manchester, Richard N. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Steeghs, Danny, E-mail: fcrawfor@fandm.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2013-10-10T23:59:59.000Z

    We present a study of PSR J1723–2837, an eclipsing, 1.86 ms millisecond binary radio pulsar discovered in the Parkes Multibeam survey. Radio timing indicates that the pulsar has a circular orbit with a 15 hr orbital period, a low-mass companion, and a measurable orbital period derivative. The eclipse fraction of ?15% during the pulsar's orbit is twice the Roche lobe size inferred for the companion. The timing behavior is significantly affected by unmodeled systematics of astrophysical origin, and higher-order orbital period derivatives are needed in the timing solution to account for these variations. We have identified the pulsar's (non-degenerate) companion using archival ultraviolet, optical, and infrared survey data and new optical photometry. Doppler shifts from optical spectroscopy confirm the star's association with the pulsar and indicate a pulsar-to-companion mass ratio of 3.3 ± 0.5, corresponding to a companion mass range of 0.4 to 0.7 M{sub ?} and an orbital inclination angle range of between 30° and 41°, assuming a pulsar mass range of 1.4-2.0 M{sub ?}. Spectroscopy indicates a spectral type of G for the companion and an inferred Roche-lobe-filling distance that is consistent with the distance estimated from radio dispersion. The features of PSR J1723–2837 indicate that it is likely a 'redback' system. Unlike the five other Galactic redbacks discovered to date, PSR J1723–2837 has not been detected as a ?-ray source with Fermi. This may be due to an intrinsic spin-down luminosity that is much smaller than the measured value if the unmeasured contribution from proper motion is large.

  16. PROBING MILLISECOND PULSAR EMISSION GEOMETRY USING LIGHT CURVES FROM THE FERMI/LARGE AREA TELESCOPE

    SciTech Connect (OSTI)

    Venter, C.; Harding, A. K. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L. [Universite de Bordeaux, Centre d'Etudes Nucleaires Bordeaux Gradignan, UMR 5797, Gradignan, 33175 (France)

    2009-12-10T23:59:59.000Z

    An interesting new high-energy pulsar sub-population is emerging following early discoveries of gamma-ray millisecond pulsars (MSPs) by the Fermi Large Area Telescope (LAT). We present results from three-dimensional emission modeling, including the special relativistic effects of aberration and time-of-flight delays and also rotational sweepback of B-field lines, in the geometric context of polar cap (PC), outer gap (OG), and two-pole caustic (TPC) pulsar models. In contrast to the general belief that these very old, rapidly rotating neutron stars (NSs) should have largely pair-starved magnetospheres due to the absence of significant pair production, we find that most of the light curves are best fit by TPC and OG models, which indicates the presence of narrow accelerating gaps limited by robust pair production-even in these pulsars with very low spin-down luminosities. The gamma-ray pulse shapes and relative phase lags with respect to the radio pulses point to high-altitude emission being dominant for all geometries. We also find exclusive differentiation of the current gamma-ray MSP population into two MSP sub-classes: light curve shapes and lags across wavebands impose either pair-starved PC (PSPC) or TPC/OG-type geometries. In the first case, the radio pulse has a small lag with respect to the single gamma-ray pulse, while the (first) gamma-ray peak usually trails the radio by a large phase offset in the latter case. Finally, we find that the flux correction factor as a function of magnetic inclination and observer angles is typically of order unity for all models. Our calculation of light curves and flux correction factor for the case of MSPs is therefore complementary to the 'ATLAS paper' of Watters et al. for younger pulsars.

  17. Semileptonic Decays

    SciTech Connect (OSTI)

    Luth, Vera G.; /SLAC

    2012-10-02T23:59:59.000Z

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  18. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect (OSTI)

    Stracka, Simone; /Milan U. /INFN, Milan; ,

    2012-04-04T23:59:59.000Z

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  19. Systematic trends in beta-delayed particle emitting nuclei: The case of beta-p-alpha emission from 21Mg

    E-Print Network [OSTI]

    M. V. Lund; M. J. G. Borge; J. A. Briz; J. Cederkäll; H. O. U. Fynbo; J. H. Jensen; B. Jonson; K. L. Laursen; T. Nilsson; A. Perea; V. Pesudo; K. Riisager; O. Tengblad

    2015-06-12T23:59:59.000Z

    We have observed beta+-delayed alpha and p-alpha emission from the proton-rich nucleus 21Mg produced at the ISOLDE facility at CERN. The assignments were cross-checked with a time distribution analysis. This is the third identified case of beta-p-alpha emission. We discuss the systematic of beta-delayed particle emission decays, show that our observed decays fit naturally into the existing pattern, and argue that the patterns are to a large extent caused by odd-even effects.

  20. The Neutral Decay Modes of the Eta-Meson

    E-Print Network [OSTI]

    B. M. K. Nefkens; J. W. Price

    2002-02-11T23:59:59.000Z

    The neutral decay modes of the eta meson are reviewed. The most recent results obtained with the Crystal Ball multiphoton detector at BNL are incorporated. This includes a new, precise result for the slope parameter alpha of the Dalitz plot in eta -> 3pi0 decay and a new, lower branching ratio for eta -> pi0 gamma gamma which is consistent with chiral perturbation theory. Recently-obtained limits are given for novel tests of CP and C invariance based on several rare eta decays.

  1. Measurement of the asymmetry parameter for the decay {Lambda}{yields}p{pi}{sup +}

    SciTech Connect (OSTI)

    Ablikim, M.; Bai, J. Z.; Bai, Y.; Cai, X.; Chen, H. S.; Chen, H. X.; Chen, J. C.; Chen, Jin; Chen, Y. B.; Chu, Y. P.; Deng, Z. Y.; Du, S. X.; Fang, J.; Fu, C. D.; Gao, C. S.; Gu, S. D.; Guo, Y. N.; He, K. L.; Heng, Y. K.; Hu, H. M. [Institute of High Energy Physics, Beijing 100049 (China)

    2010-01-01T23:59:59.000Z

    Based on a sample of 58x10{sup 6}J/{psi} decays collected with the BESII detector at the BEPC, the {Lambda} decay parameter {alpha}{sub {Lambda}}for {Lambda}{yields}p{pi}{sup +} is measured using about 9000 J/{psi}{yields}{Lambda}{Lambda}{yields}pp{pi}{sup +{pi}-} decays. A fit to the joint angular distributions yields {alpha}{sub {Lambda}({Lambda}{yields}p{pi}{sup +})}=-0.755{+-}0.083{+-}0.063, where the first error is statistical, and the second systematic.

  2. Long range alpha particle detector

    DOE Patents [OSTI]

    MacArthur, D.W.; Wolf, M.A.; McAtee, J.L.; Unruh, W.P.; Cucchiara, A.L.; Huchton, R.L.

    1993-02-02T23:59:59.000Z

    An alpha particle detector capable of detecting alpha radiation from distant sources. In one embodiment, a high voltage is generated in a first electrically conductive mesh while a fan draws air containing air molecules ionized by alpha particles through an air passage and across a second electrically conductive mesh. The current in the second electrically conductive mesh can be detected and used for measurement or alarm. The detector can be used for area, personnel and equipment monitoring.

  3. Nuclear Alpha-Particle Condensates

    E-Print Network [OSTI]

    T. Yamada; Y. Funaki; H. Horiuchi; G. Roepke; P. Schuck; A. Tohsaki

    2011-03-21T23:59:59.000Z

    The $\\alpha$-particle condensate in nuclei is a novel state described by a product state of $\\alpha$'s, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical $\\alpha$-particle condensate is the Hoyle state ($E_{x}=7.65$ MeV, $0^+_2$ state in $^{12}$C), which plays a crucial role for the synthesis of $^{12}$C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the $\\alpha$ particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that $\\alpha$-particle condensate states also exist in heavier $n\\alpha$ nuclei, like $^{16}$O, $^{20}$Ne, etc. For instance the $0^+_6$ state of $^{16}$O at $E_{x}=15.1$ MeV is identified from a theoretical analysis as being a strong candidate of a $4\\alpha$ condensate. The calculated small width (34 keV) of $0^+_6$, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as $^{11}$B and $^{13}$C, we discuss candidates for the product states of clusters, composed of $\\alpha$'s, triton's, and neutrons etc. The relationship of $\\alpha$-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for $\\alpha$ particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.

  4. Constraints on Neutron Star Parameters from Burst Oscillation Light Curves of the Accreting Millisecond Pulsar XTE J1814-338

    E-Print Network [OSTI]

    Sudip Bhattacharyya; Tod E. Strohmayer; M. Coleman Miller; Craig B. Markwardt

    2004-10-11T23:59:59.000Z

    Detailed modeling of the millisecond brightness oscillations during thermonuclear bursts from low mass X-ray binaries can provide important information about neutron star structure. Until now the implementation of this idea has not been entirely successful, largely because of the negligible harmonic content in burst oscillation lightcurves. However, the recent discovery of non-sinusoidal burst oscillation lightcurves from the accreting millisecond pulsar XTE J1814-338 has changed this situation. We, therefore, for the first time, make use of this opportunity to constrain neutron star parameters. In our detailed study of the lightcurves of 22 bursts, we fit the burst oscillation lightcurves with fully general relativistic models that include light-bending and frame-dragging for lightcurve calculation, and compute numerically the structure of neutron stars using realistic equations of state. We find that for our model and parameter grid values, at the 90% confidence level, Rc^2/GM > 4.2 for the neutron star in XTE J1814-338. We also find that the photons from the thermonuclear flash come out through the layers of accreted matter under conditions consistent with Thomson scattering, and show that the secondary companion is a hydrogen burning main sequence star, with possible bloating (probably due to X-ray heating).

  5. Scattering in the inner accretion disk and the waveforms and polarization of millisecond flux oscillations in LMXBs

    E-Print Network [OSTI]

    Sergei Y. Sazonov; Rashid A. Sunyaev

    2000-11-19T23:59:59.000Z

    The scattering by the inner accretion disk of X-ray radiation generated near the surface of a spinning neutron star in a low-mass X-ray binary (LMXB) has observable effects on the waveforms of millisecond X-ray flux oscillations produced e.g. during type-I bursts or in the millisecond pulsar SAX J1808.4--3658. We study these effects in the framework of a simplified model in which there is a single emitting spot on the stellar surface, which is visible both directly and in X-rays scattered from the disk. The main signature of scattering from a thin disk is that the pulse of scattered flux leads (if the star rotates in the same sense as the disk) or lags (in the contrary case) the primary pulse of direct emission by a quarter of a spin cycle. This is caused by Doppler boosting of radiation in the sub-relativistic Keplerian flow. The disk-scattered flux is revealed better in energy-resolved waveforms and the phase dependence of the polarized flux component. The phenomenon discussed permits direct testing of the presence of standard thin disks near the neutron stars in LMXBs and should be observable with future X-ray timing experiments having a few times better sensitivity than RXTE and also with sensitive X-ray polarimeters.

  6. Millisecond dip events in the 2007 RXTE/PCA data of Sco X-1 and the TNO size distribution

    E-Print Network [OSTI]

    Liu, Chih-Yuan; Liang, Jau-Shian; King, Sun-Kun

    2008-01-01T23:59:59.000Z

    Millisecond dips in the RXTE/PCA archival data of Sco X-1 taken from 1996 to 2002 were reported recently. Those dips were found to be most likely caused by instrumental dead time but may also contain some true astronomical events, which were interpreted as the occultation of X-rays from Sco X-1 by Trans-Neptunian Objects (TNO) of 100-m size. Here we report the results of search for millisecond dip events with the new RXTE/PCA data of Sco X-1 taken in year 2007. Adopting the same selection criteria as that in the previous study, we found only 3 dip events in 72-ks data, much fewer than the 107 events found in the 560-ks data taken from 1996 to 2002 reported earlier. The new data provides more detailed information of individual `very large events' (VLEs), which is not available in the old archival data. Although the number of VLEs does not obviously increase during the occurrence of dip events, all the 3 dip events are coincident in time with VLEs that have no flags set for any of the propane or the 6 main xeno...

  7. Top-quark processes at NLO in production and decay

    SciTech Connect (OSTI)

    Campbell, John M.; Ellis, R.Keith

    2012-04-01T23:59:59.000Z

    We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top production, and t-channel single-top production into the product of an amplitude for production and an amplitude for decay. In this way we can retain all spin correlations. Both the production and the decay amplitudes are calculated consistently at next-to-leading order in alpha_s. The full dependence on the b-quark mass is also kept. Phenomenological results are presented for various kinematic distributions at the LHC and for the top quark forward-backward asymmetry at the Tevatron.

  8. Study of Penguin Pollution in the B^0 -> J/psi K_S Decay

    E-Print Network [OSTI]

    Satoshi Mishima

    2007-03-18T23:59:59.000Z

    We study the penguin pollution in the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \\alpha_s, m_b being the b quark mass and \\alpha_s the strong coupling constant. The deviation \\Delta S_{J/psi K_S} of the mixing-induced CP asymmetry from sin(2\\phi_1) and the direct CP asymmetry A_{J/psi K_S} are both found to be of O(10^{-3}) in a formalism that combines the QCD-improved factorization and perturbative QCD approaches.

  9. Baryon helicity in B decay

    SciTech Connect (OSTI)

    Suzuki, Mahiko

    2005-05-13T23:59:59.000Z

    We extend the perturbative argument of helicity amplitudes to the two-body baryonic decays of B decays.

  10. Accelerated alpha radiation damage in a ceramic waste form, interim results

    SciTech Connect (OSTI)

    Frank, S. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T. P.; Sinkler, W.; Esh, D.; Goff, K. M.

    1999-11-11T23:59:59.000Z

    Interim results are presented on the alpha-decay damage study of a {sup 238}Pu-loaded ceramic waste form (CWF). The waste form was developed to immobilize fission products and transuranic species accumulated from the electrometallurgical treatment of spent nuclear fuel. To evaluate the effects of {alpha}-decay damage on the waste form the {sup 238}Pu-loaded material was analyzed by (1) x-ray diffraction (XRD), (2) microstructure characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy and wavelength dispersive spectroscopy (EDS/WDS) and electron diffraction, (3) bulk density measurements and (4) waste form durability, performed by the product consistency test (PCT). While the predominate phase of plutonium in the CWF, PuO{sub 2}, shows the expected unit cell expansion due to {alpha}-decay damage, currently no significant change has occurred to the macro- or microstructure of the material. The major phase of the waste form is sodalite and contains very little Pu, although the exact amount is unknown. Interestingly, measurement of the sodalite phase unit cell is also showing very slight expansion; again, presumably from {alpha}-decay damage.

  11. Contribution of the induced tensor form factor to the A =8. beta. -. nu. -. alpha. angular correlation

    SciTech Connect (OSTI)

    De Braeckeleer, L. (Physics Department, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1992-04-01T23:59:59.000Z

    Experimental limits on the second class induced tensor weak current are reviewed. A method, involving the measurement of the {beta}-{nu}-{alpha} angular correlations in {sup 8}Li and {sup 8}B decays is proposed to test for this current with improved precision.

  12. EEG alpha power and alpha power asymmetry in sleep and wakefulness

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    EEG alpha power and alpha power asymmetry in sleep and wakefulness RUTH M. BENCA,a,b WILLIAM H--Madison, USA Abstract Asymmetry of waking electroencephalography ~EEG! alpha power in frontal regions has been regarding alpha asymmetry during sleep. The present study was performed to compare alpha power and alpha

  13. Development of CaMoO4 crystal scintillators for double beta decay experiment with 100-Mo

    E-Print Network [OSTI]

    A. N. Annenkov; O. A. Buzanov; F. A. Danevich; A. Sh. Georgadze; S. K. Kim; H. J. Kim; Y. D. Kim; V. V. Kobychev; V. N. Kornoukhov; M. Korzhik; J. I. Lee; O. Missevitch; V. M. Mokina; S. S. Nagorny; A. S. Nikolaiko; D. V. Poda; R. B. Podviyanuk; D. J. Sedlak; O. G. Shkulkova; J. H. So; I. M. Solsky; V. I. Tretyak; S. S. Yurchenko

    2007-07-10T23:59:59.000Z

    Energy resolution, alpha/beta ratio, pulse-shape discrimination for gamma rays and alpha particles, temperature dependence of scintillation properties, and radioactive contamination were studied with CaMoO4 crystal scintillators. A high sensitivity experiment to search for neutrinoless double beta decay of 100-Mo by using CaMoO4 scintillators is discussed.

  14. Millisecond dip events in the 2007 RXTE/PCA data of Sco X-1 and the TNO size distribution

    E-Print Network [OSTI]

    Chih-Yuan Liu; Hsiang-Kuang Chang; Jau-Shian Liang; Sun-Kun King

    2008-05-12T23:59:59.000Z

    Millisecond dips in the RXTE/PCA archival data of Sco X-1 taken from 1996 to 2002 were reported recently. Those dips were found to be most likely caused by instrumental dead time but may also contain some true astronomical events, which were interpreted as the occultation of X-rays from Sco X-1 by Trans-Neptunian Objects (TNO) of 100-m size. Here we report the results of search for millisecond dip events with the new RXTE/PCA data of Sco X-1 taken in year 2007. Adopting the same selection criteria as that in the previous study, we found only 3 dip events in 72-ks data, much fewer than the 107 events found in the 560-ks data taken from 1996 to 2002 reported earlier. The new data provides more detailed information of individual `very large events' (VLEs), which is not available in the old archival data. Although the number of VLEs does not obviously increase during the occurrence of dip events, all the 3 dip events are coincident in time with VLEs that have no flags set for any of the propane or the 6 main xenon anodes. It is a strong indication of instrumental effects. No significant dips which might be real occultation by 60 -- 100 m TNOs were observed. With only 72-ks data, however, the previously proposed possibility that about 10 percent of the dip events might not be instrumental still cannot be strictly excluded. Using the absence of those anomalous VLEs as the criterion for identifying non-instrumental dip events, we found, at a lower confidence level, 4 dip events of duration 8 - 10 ms in the 72-ks data. Upper limits to the size distribution of TNOs at the small size end are suggested.

  15. Pulsed Gamma-Rays From the Millisecond Pulsar J0030+0451 with the Fermi Large Area Telescope

    SciTech Connect (OSTI)

    Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M. /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Battelino, M.; /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, Elliott D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /LPCE, Orleans /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U.; /more authors..

    2011-11-17T23:59:59.000Z

    We report the discovery of gamma-ray pulsations from the nearby isolated millisecond pulsar PSR J0030+0451 with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). This discovery makes PSR J0030+0451 the second millisecond pulsar to be detected in gamma-rays after PSR J0218+4232, observed by the EGRET instrument on the Compton Gamma Ray Observatory. The spin-down power {dot E} = 3.5 x 10{sup 33} ergs s{sup -1} is an order of magnitude lower than the empirical lower bound of previously known gamma-ray pulsars. The emission profile is characterized by two narrow peaks, respectively 0.07 {+-} 0.01 and 0.08 {+-} 0.02 wide, separated by 0.44 {+-} 0.02 in phase. The first gamma-ray peak falls 0.15 {+-} 0.01 after the main radio peak. The pulse shape is similar to that of the 'normal' gamma-ray pulsars. An exponentially cut-off power-law fit of the emission spectrum leads to an integral photon flux above 100 MeV of (6.76 {+-} 1.05 {+-} 1.35) x 10{sup -8} cm{sup -2} s{sup -1} with cut-off energy (1.7 {+-} 0.4 {+-} 0.5) GeV. Based on its parallax distance of (300 {+-} 90) pc, we obtain a gamma-ray efficiency L{sub {gamma}}/{dot E} {approx_equal} 15% for the conversion of spin-down energy rate into gamma-ray radiation, assuming isotropic emission.

  16. Alpha Kappa Alpha Artificial Records, 1932-2000s

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    THE OTHER SIDE OF THE RAINBOW ..... -; ALPHA KAPPA ALPHA SORORITY DELTA CHAPTER A REAL POT OF GOLD LIFt" EV'RY vOICE AND SING Li.6,t eV'!LY vo-i.c.e and ~-i.ng, T-i...t ea-uh and heaVe.l1 iU'lg, KUla w-i.,th tne. hMmolUe!.> 06 Llbeuy; Lei oun. !Le60...

  17. Hybrid baryons [alpha].

    SciTech Connect (OSTI)

    Page, P. R. (Philip R.)

    2002-01-01T23:59:59.000Z

    The authors review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modeled by both the bag and flux tube models. The low lying hybrid baryon is N 1/2{sup +} with a mass of 1.5 - 1.8 GeV. Hybrid baryons can be produced in the glue rich processes of diffractive {gamma}N and {pi}N production, {Psi} decays and p{bar p} annihilation. We review the current status of research on three quarks with a gluonic excitation, called a hybrid baryon. The excitation is not an orbital or radial excitation between the quarks. Hybrid baryons have also been reviewed elsewhere. The Mercedes-Benz logl in Figure 1 indicates two possible views of the confining interaction of three quarks, an essential issue in the study of hybrid baryons. In the logo the three points where the Y shape meets the boundary circle should be identified with the three quarks. There are two possibilities fo rthe interaction of the quarks: (1) a pairwise interaction of the quarks represented by the circle, or (2) a Y shaped interaction between the quarks, represented by the Y-shape in the logo.

  18. Double Beta Decay: Scintillators

    E-Print Network [OSTI]

    Mark C. Chen

    2008-10-20T23:59:59.000Z

    Scintillator detectors can be used in experiments searching for neutrinoless double beta decay. A wide variety of double beta decay candidate isotopes can be made into scintillators or can be loaded into scintillators. Experimental programs developing liquid xenon, inorganic crystals, and Nd-loaded liquid scintillator are described in this review. Experiments with 48Ca and 150Nd benefit from their high endpoint which places the neutrinoless double beta decay signal above most backgrounds from natural radioactivity.

  19. B decays and Supersymmetry

    E-Print Network [OSTI]

    Anirban Kundu

    2002-05-10T23:59:59.000Z

    I discuss how supersymmetry affects various observables in B decays, and point out the interesting channels in the context of B factories.

  20. SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra

    SciTech Connect (OSTI)

    Madland, D.G.; Arthur, E.D.; Estes, G.P.; Stewart, J.E.; Bozoian, M.; Perry, R.T.; Parish, T.A.; Brown, T.H.; England, T.R.; Wilson, W.B.; Charlton, W.S.

    1999-09-01T23:59:59.000Z

    SOURCES 4A is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to the decay of radionuclides. The code is capable of calculating ({alpha},n) source rates and spectra in four types of problems: homogeneous media (i.e., a mixture of {alpha}-emitting source material and low-Z target material), two-region interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material), three-region interface problems (i.e., a thin slab of low-Z target material sandwiched between {alpha}-emitting source material and low-Z target material), and ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 43 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 89 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code outputs the magnitude and spectra of the resultant neutron source. It also provides an analysis of the contributions to that source by each nuclide in the problem.

  1. Double beta decay experiments

    E-Print Network [OSTI]

    A. S. Barabash

    2006-02-22T23:59:59.000Z

    The present status of double beta decay experiments are reviewed. The results of the most sensitive experiments, NEMO-3 and CUORICINO, are discussed. Proposals for future double beta decay experiments are considered. In these experiments sensitivity for the effective neutrino mass will be on the level of (0.1-0.01) eV.

  2. Double beta decay experiments

    E-Print Network [OSTI]

    A. S. Barabash

    2011-07-28T23:59:59.000Z

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  3. Characterization of ZnSe scintillating bolometers for Double Beta Decay

    E-Print Network [OSTI]

    C. Arnaboldi; S. Capelli; O. Cremonesi; L. Gironi; M. Pavan; G. Pessina; S. Pirro

    2010-06-30T23:59:59.000Z

    ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82Se are presented.

  4. Rare B Decays and B Decay Dynamics

    E-Print Network [OSTI]

    William T. Ford

    2005-10-20T23:59:59.000Z

    I present some recent measurements of B meson decay rates to leptonic and charmless hadronic final states, as well as of CP-violation charge asymmetries and other features. I sketch the theoretical frameworks used to predict these, and indicate the level of agreement of the estimates with experiment.

  5. Analytic Perturbation Theory Model for QCD and Upsilon Decay

    E-Print Network [OSTI]

    Shirkov, D V

    2006-01-01T23:59:59.000Z

    An elegant and more precise formula for the 3-loop perturbative QCD coupling is discussed. It improves the common expression (e.g., canonized by PDG) in few GeV region. On its base, we propose simple analytic Model for ghost-free QCD running couplings and their effective powers within the Analytic Perturbation Theory, in both the space-like (Euclidean) and time-like (Minkowskian) regions, very accurate in the range above 1 GeV. Effectiveness of the new Model is illustrated by the example of Upsilon(1S) decay where the standard analysis gives $\\alpha_s(M_{\\Ups})=0.170\\pm 0.004$ value that is inconsistent with the bulk of data. Instead, we obtain $\\alpha_s(M_{\\Ups})=0.185\\pm 0.005$ that corresponds to $\\alpha_s(M_Z)=0.120\\pm 0.002 $ that is close to the world average.

  6. SOURCES 4C : a code for calculating ([alpha],n), spontaneous fission, and delayed neutron sources and spectra.

    SciTech Connect (OSTI)

    Wilson, W. B. (William B.); Perry, R. T. (Robert T.); Shores, E. F. (Erik F.); Charlton, W. S. (William S.); Parish, Theodore A.; Estes, G. P. (Guy P.); Brown, T. H. (Thomas H.); Arthur, Edward D. (Edward Dana),; Bozoian, Michael; England, T. R.; Madland, D. G.; Stewart, J. E. (James E.)

    2002-01-01T23:59:59.000Z

    SOURCES 4C is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to radionuclide decay. The code is capable of calculating ({alpha},n) source rates and spectra in four types of problems: homogeneous media (i.e., an intimate mixture of a-emitting source material and low-Z target material), two-region interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material), three-region interface problems (i.e., a thin slab of low-Z target material sandwiched between {alpha}-emitting source material and low-Z target material), and ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 44 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 107 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code provides the magnitude and spectra, if desired, of the resultant neutron source in addition to an analysis of the'contributions by each nuclide in the problem. LASTCALL, a graphical user interface, is included in the code package.

  7. Testing the millisecond pulsar scenario of the Galactic center gamma-ray excess with very high energy gamma-rays

    E-Print Network [OSTI]

    Qiang Yuan; Kunihito Ioka

    2015-02-09T23:59:59.000Z

    The recent analyses of the Fermi Large Area Telescope data show an extended GeV $\\gamma$-ray excess on top of the expected diffuse background in the Galactic center region, which can be explained with annihilating dark matter or a population of millisecond pulsars (MSPs). We propose to observe the very high energy $\\gamma$-rays for distinguishing the MSP scenario from the dark matter scenario. The GeV $\\gamma$-ray MSPs should release most energy to the relativistic $e^{\\pm}$ wind, which will diffuse in the Galaxy and radiate TeV $\\gamma$-rays through inverse Compton scattering and bremsstrahlung processes. By calculating the spectrum and spatial distribution, we show that such emission is detectable with the next generation very high energy $\\gamma$-ray observatory, the Cherenkov Telescope Array (CTA), under reasonable model parameters. It is essential to search for the multi-wavelength counterparts to the GeV $\\gamma$-ray excess for solving this mystery in the high energy universe.

  8. Gamma-ray emission states in the redback millisecond pulsar binary system PSR J1227-4853

    E-Print Network [OSTI]

    Bednarek, W

    2015-01-01T23:59:59.000Z

    Long expected transition states between the rotation powered and accretion powered non-thermal emission in the millisecond pulsar binary systems have been recently observed in the case of three objects PSR J1023+0038, PSR J1824-2452, and PSR J1227-4859. Surprisingly, the transition is related to the significant change in the $\\gamma$-ray flux being a factor of a few higher with the presence of an accretion disk. The origin of this enhanced emission seems to be related to the penetration of the inner pulsar magnetosphere by the accretion disk. We propose that the radiation processes, characteristic for the rotation powered pulsar, can co-exist with the presence of an accretion disk in the inner pulsar magnetosphere. In our scenario additional $\\gamma$-ray emission is produced by secondary leptons, originated close to the acceleration gap, which Compton up-scatter thermal radiation from the accretion disk to GeV energies. The accretion disk penetrates deep into the pulsar magnetosphere allowing the matter to fa...

  9. The Connection Between Low-Mass X-ray Binaries and (Millisecond) Pulsars: A Binary Evolution Perspective

    E-Print Network [OSTI]

    Christopher J. Deloye

    2007-10-01T23:59:59.000Z

    I review the evolutionary connection between low-mass X-ray binaries (LMXBs) and pulsars with binary companions (bPSRs) from a stellar binary evolution perspective. I focus on the evolution of stellar binaries with end-states consisting of a pulsar with a low-mass (<1.0 solar mass) companion, starting at the point the companion's progenitor first initiates mass transfer onto the neutron star. Whether this mass transfer is stable and the physics driving ongoing mass transfer partitions the phase space of the companions's initial mass and initial orbital period into five regions. The qualitative nature of the mass-transfer process and the binary's final end-state differ between systems in each region; four of these regions each produce a particular class of LMXBs. I compare the theoretical expectations to the populations of galactic field LMXBs with companion-mass constraints and field bPSRs. I show that the population of accreting millisecond pulsars are all identified with only two of the four LMXB classes and that these systems do not have readily identifiable progeny in the bPSR population. I discuss which sub-populations of bPSRs can be explained by binary evolution theory and those that currently are not. Finally I discuss some outstanding questions in this field.

  10. FIVE NEW MILLISECOND PULSARS FROM A RADIO SURVEY OF 14 UNIDENTIFIED FERMI-LAT GAMMA-RAY SOURCES

    SciTech Connect (OSTI)

    Kerr, M. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Johnson, T. J. [National Academy of Sciences, Washington, DC 20001 (United States); Ferrara, E. C.; Harding, A. K. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Hessels, J. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Johnston, S.; Keith, M.; Reynolds, J. E. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Epping, NSW 1710 (Australia); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), Charlottesville, VA 22903 (United States); Ray, P. S.; Wood, K. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Sarkissian, J., E-mail: kerrm@stanford.edu, E-mail: fernando@astro.columbia.edu, E-mail: tyrel.j.johnson@gmail.com [CSIRO Parkes Observatory, Parkes, NSW 2870 (Australia)

    2012-03-20T23:59:59.000Z

    We have discovered five millisecond pulsars (MSPs) in a survey of 14 unidentified Fermi Large Area Telescope sources in the southern sky using the Parkes radio telescope. PSRs J0101-6422, J1514-4946, and J1902-5105 reside in binaries, while PSRs J1658-5324 and J1747-4036 are isolated. Using an ephemeris derived from timing observations of PSR J0101-6422 (P = 2.57 ms, DM = 12 pc cm{sup -3}), we have detected {gamma}-ray pulsations and measured its proper motion. Its {gamma}-ray spectrum (a power law of {Gamma} = 0.9 with a cutoff at 1.6 GeV) and efficiency are typical of other MSPs, but its radio and {gamma}-ray light curves challenge simple geometric models of emission. The high success rate of this survey-enabled by selecting {gamma}-ray sources based on their detailed spectral characteristics-and other similarly successful searches indicate that a substantial fraction of the local population of MSPs may soon be known.

  11. Coherence of burst oscillations and accretion-powered pulsations in the accreting millisecond pulsar XTE J1814-338

    E-Print Network [OSTI]

    Anna L. Watts; Alessandro Patruno; Michiel van der Klis

    2008-10-02T23:59:59.000Z

    X-ray timing of the accretion-powered pulsations during the 2003 outburst of the accreting millisecond pulsar XTE J1814-338 has revealed variation in the pulse time of arrival residuals. These can be interpreted in several ways, including spin-down and wandering of the fuel impact point around the magnetic pole. In this Letter we show that the burst oscillations of this source are coherent with the persistent pulsations, to the level where they track all of the observed fluctuations. Only one burst, which occurs at the lowest accretion rates, shows a significant phase offset. We discuss what might lead to such rigid phase-locking between the modulations in the accretion and thermonuclear burst emission, and consider the implications for spin variation and the burst oscillation mechanism. Wandering of the fuel impact hot spot around a fixed magnetic pole seems the most likely cause for the accretion-powered pulse phase variations. This means that the burst asymmetry is coupled to the hot spot, not the magnetic pole. If premature ignition at this point (due to higher local temperatures) triggers a burning front that stalls before spreading over the entire surface, the resulting localized nuclear hot spot may explain the unusual burst and burst oscillation properties of this source.

  12. ACCELERATED ORBITAL EXPANSION AND SECULAR SPIN-DOWN OF THE ACCRETING MILLISECOND PULSAR SAX J1808.4-3658

    SciTech Connect (OSTI)

    Patruno, Alessandro; Bult, Peter; Wijnands, Rudy; Van der Klis, Michiel [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Gopakumar, Achamveedu [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Colaba, Mumbai 400005 (India); Hartman, Jacob M. [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Chakrabarty, Deepto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2012-02-20T23:59:59.000Z

    The accreting millisecond pulsar SAX J1808.4-3658 has shown a peculiar orbital evolution in the past with an orbital expansion much faster than expected from standard binary evolutionary scenarios. Previous limits on the pulsar spin frequency derivative during transient accretion outbursts were smaller than predicted by standard magnetic accretion torque theory, while the spin evolution between outbursts was consistent with magnetic dipole spin-down. In this Letter, we present the results of a coherent timing analysis of the 2011 outburst observed by the Rossi X-Ray Timing Explorer and extend our previous long-term measurements of the orbital and spin evolution over a baseline of 13 years. We find that the expansion of the 2 hr orbit is accelerating at a rate of P-double dot{sub b} approx. = 1.6 x 10{sup -20} s s{sup -2} and we interpret this as the effect of short-term angular momentum exchange between the mass donor and the orbit. The gravitational quadrupole coupling due to variations in the oblateness of the companion can be a viable mechanism for explaining the observations. No significant spin frequency derivatives are detected during the 2011 outburst (|{nu}-dot| < or approx. 4 x 10{sup -13} Hz s{sup -1}) and the long-term spin-down remains stable over 13 years with {nu}-dot approx. = -10{sup -15} Hz s{sup -1}.

  13. Level statistics of one-dimensional Schrödinger operators with random decaying potential

    E-Print Network [OSTI]

    Shinichi Kotani; Fumihiko Nakano

    2014-12-29T23:59:59.000Z

    We study the level statistics of one-dimensional Schr\\"odinger operator with random potential decaying like $x^{-\\alpha}$ at infinity. We consider the point process $\\xi_L$ consisting of the rescaled eigenvalues and show that : (i)(ac spectrum case) for $\\alpha > \\frac 12$, $\\xi_L$ converges to a clock process, and the fluctuation of the eigenvalue spacing converges to Gaussian. (ii)(critical case) for $\\alpha = \\frac 12$, $\\xi_L$ converges to the limit of the circular $\\beta$-ensemble.

  14. SOURCES-3A: A code for calculating ({alpha}, n), spontaneous fission, and delayed neutron sources and spectra

    SciTech Connect (OSTI)

    Perry, R.T.; Wilson, W.B.; Charlton, W.S.

    1998-04-01T23:59:59.000Z

    In many systems, it is imperative to have accurate knowledge of all significant sources of neutrons due to the decay of radionuclides. These sources can include neutrons resulting from the spontaneous fission of actinides, the interaction of actinide decay {alpha}-particles in ({alpha},n) reactions with low- or medium-Z nuclides, and/or delayed neutrons from the fission products of actinides. Numerous systems exist in which these neutron sources could be important. These include, but are not limited to, clean and spent nuclear fuel (UO{sub 2}, ThO{sub 2}, MOX, etc.), enrichment plant operations (UF{sub 6}, PuF{sub 4}, etc.), waste tank studies, waste products in borosilicate glass or glass-ceramic mixtures, and weapons-grade plutonium in storage containers. SOURCES-3A is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to the decay of radionuclides in homogeneous media (i.e., a mixture of {alpha}-emitting source material and low-Z target material) and in interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material). The code is also capable of calculating the neutron production rates due to ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 43 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 89 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code outputs the magnitude and spectra of the resultant neutron source. It also provides an analysis of the contributions to that source by each nuclide in the problem.

  15. Isospin mixing and energy distributions in three-body decay

    E-Print Network [OSTI]

    E. Garrido; D. V. Fedorov; H. O. U. Fynbo; A. S. Jensen

    2007-03-21T23:59:59.000Z

    The structure of the second 2$^+$ resonance in $^{6}$Li is investigated with special emphasis on its isospin 0 components. The wave functions are computed in a three-body model ($\\alpha$+$n$+$p$) using the hyperspherical adiabatic expansion method combined with complex scaling. In the decay into three free particles the symmetry conserving short-range interaction dominates at short distance whereas the symmetry breaking Coulomb interaction dominates at intermediate and large distances resulting in substantial isospin mixing. We predict the mixing and the energy distributions of the fragments after decay. Computations are consistent with available experiments. We conjecture that nuclear three-body decays frequently produce such large isospin mixing at large distance where the energy distributions. are determined.

  16. RARE KAON DECAYS.

    SciTech Connect (OSTI)

    LITTENBERG, L.

    2005-07-19T23:59:59.000Z

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  17. Neutrinoless double beta decay

    E-Print Network [OSTI]

    K. Zuber

    2012-01-23T23:59:59.000Z

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations are presented as well as the current status of experiments. Finally an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  18. Constraining Decaying Dark Matter

    E-Print Network [OSTI]

    Ran Huo

    2011-07-13T23:59:59.000Z

    We revisited the decaying dark matter (DDM) model, in which one collisionless particle decays early into two collisionless particles, that are potentially dark matter particles today. The effect of DDM will be manifested in the cosmic microwave background (CMB) and structure formation. With a systematic modification of CMB calculation tool \\texttt{camb}, we can numerically calculated this effect, and compare it to observations. Further Markov Chain Monte Carlo \\texttt{cosmomc} runnings update the constraints in that model: the free streaming length $\\lambda_{FS}\\lesssim0.5$Mpc for nonrelativistic decay, and $((M_{DDM}/keV) Y)^2 (T_d/yr)\\lesssim5\\times10^{-5}$ for relativistic decay.

  19. Double Beta Decay

    E-Print Network [OSTI]

    Steven R. Elliott; Petr Vogel

    2002-02-27T23:59:59.000Z

    The motivation, present status, and future plans of the search for the neutrinoless double beta decay are reviewed. It is argued that, motivated by the recent observations of neutrino oscillations, there is a reasonable hope that neutrinoless double beta decay corresponding to the neutrino mass scale suggested by oscillations, of about 50 meV, actually exists. The challenges to achieve the sensitivity corresponding to this mass scale, and plans to overcome them, are described.

  20. Preliminary results from the lunar prospector alpha particle spectrometer

    SciTech Connect (OSTI)

    Lawson, S. L. (Stefanie L.)

    2001-01-01T23:59:59.000Z

    The Lunar Prospector Alpha Particle Spectrometer (LP APS) builds on Apollo heritage and maps the distribution of outgassing sites on the Moon. The APS searches for lunar surface gas release events and maps their distribution by detecting alpha particles produced by the decay of gaseous radon-222 (5.5 MeV, 3.8 day half-life) and solid polonium-210 (5.3 MeV, 138 day half-life, but remains on the surface with a 21 year half-life as lead-210), which are radioactive daughters from the decay of uranium-238. Radon is in such small quantities that it is not released directly from the lunar interior, rather it is entrained in a stream of gases and serves as a tracer for such gases. Once released, the radon spreads out by 'bouncing' across the surface on ballistic trajectories in a random-walk process. The 3.8 day half-life of radon-222 allows the gas to spread out by several 100 km before it decays and allows the APS to detect gas release events up to a few days after they occur. The long residence time (10s of years) of the lead-210 precursor to the polonium-210 allows the mapping of gas vents which have been active over the last approximately 50 years. Because radon and polonium are daughter products of the decay of uranium, the background level of alpha particle activity is a function of the lunar crustal uranium distribution. Using radioactive radon and polonium as tracers, the Apollo 15 and 16 Command Module orbital alpha particle experiments obtained evidence for the release of gases at several sites beneath the orbit tracks, especially over the Aristarchus Plateau and Mare Fecunditatis [1]. Aristarchus crater had previously been identified by ground-based observers as the site of transient optical events [2]. The Apollo 17 surface mass spectrometer showed that argon-40 is released from the lunar interior every few months, apparently in concert with some of the shallow moonquakes that are believed to be of tectonic origin [3]. The latter tectonic events could be associated with very young scarps identified in the lunar highlands [4] and are believed to indicate continued global contraction. Such quakes could open fissures leading to the release of gases that are trapped below the surface. The detection of radon-222 outgassing events at the margins of Fecunditatis basin was surprising because the observed surface distribution of uranium and thorium do not extend sufficiently eastward to cover Fecunditatis. If the Apollo detections prove sound, then those alpha particle emissions indicate substantial subsurface concentrations of uranium-238 within Fecunditatis. A primary goal of the APS was to map gas-release events, thus allowing both an appraisal of the current level of tectonic activity on the Moon and providing a probe of subsurface uranium concentrations.

  1. A test of the millisecond magnetar central engine model of gamma-ray bursts with swift data

    SciTech Connect (OSTI)

    Lü, Hou-Jun; Zhang, Bing, E-mail: lhj@physics.unlv.edu, E-mail: zhang@physics.unlv.edu [Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, NV 89154 (United States)

    2014-04-10T23:59:59.000Z

    A rapidly spinning, strongly magnetized neutron star (magnetar) has been proposed as one possible candidate of the central engine of gamma-ray bursts (GRBs). We systematically analyze the Swift/XRT light curves of long GRBs detected before 2013 August, and characterize them into four categories based on how likely they may harbor a magnetar central engine: Gold, Silver, Aluminum, and Non-magnetar. We also independently analyze the data of short GRBs with a putative magnetar central engine. We then perform a statistical study of various properties of the magnetar samples and the non-magnetar sample, and investigate whether the data are consistent with the hypothesis that there exist two types of central engines. By deriving the physical parameters of the putative magnetars, we find that the observations of the Gold and Silver samples are generally consistent with the predictions of the magnetar model. For a reasonable beaming factor for long GRBs, the derived magnetar surface magnetic field B{sub p} and initial spin period P {sub 0} fall into the reasonable range. Magnetar winds in short GRBs, on the other hand, are consistent with being isotropic. No GRB in the magnetar sample has a beam-corrected total energy exceeding the maximum energy budget defined by the initial spin energy of the magnetar, while some non-magnetar GRBs do violate such a limit. With beaming correction, on average the non-magnetar sample is more energetic and luminous than the magnetar samples. Our analysis hints that millisecond magnetars are likely operating in a good fraction, but probably not all, GRBs.

  2. ALPHN: A computer program for calculating ([alpha], n) neutron production in canisters of high-level waste

    SciTech Connect (OSTI)

    Salmon, R.; Hermann, O.W.

    1992-10-01T23:59:59.000Z

    The rate of neutron production from ([alpha], n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ([alpha], n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ([alpha], n) neutron production of each actinide in neutrons per second and the total for the canister. The ([alpha], n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  3. ALPHN: A computer program for calculating ({alpha}, n) neutron production in canisters of high-level waste

    SciTech Connect (OSTI)

    Salmon, R.; Hermann, O.W.

    1992-10-01T23:59:59.000Z

    The rate of neutron production from ({alpha}, n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ({alpha}, n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ({alpha}, n) neutron production of each actinide in neutrons per second and the total for the canister. The ({alpha}, n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  4. Alpha

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973ManagedStrategic|AljazeeraO S o'ware a nd D ata Alok

  5. Monotonic Local Decay Estimates

    E-Print Network [OSTI]

    Avy Soffer

    2011-10-29T23:59:59.000Z

    For the Hamiltonian operator H = -{\\Delta}+V(x) of the Schr\\"odinger Equation with a repulsive potential, the problem of local decay is considered. It is analyzed by a direct method, based on a new, L^2 bounded, propagation observable. The resulting decay estimate, is in certain cases monotonic in time, with no "Quantum Corrections". This method is then applied to some examples in one and higher dimensions. In particular the case of the Wave Equation on a Schwarzschild manifold is redone: Local decay, stronger than the known ones are proved (minimal loss of angular derivatives and lower order of radial derivatives of initial data). The method developed here can be an alternative in some cases to the Morawetz type estimates, with L^2-multipliers replacing the first order operators. It provides an alternative to Mourre's method, by including thresholds and high energies.

  6. Latest results of NEXT-DEMO, the prototype of the NEXT 100 double beta decay experiment

    E-Print Network [OSTI]

    Serra, L; Martin-Albo, J; Sorel, M; Gomez-Cadenas, J J

    2014-01-01T23:59:59.000Z

    NEXT-DEMO is a 1:4.5 scale prototype of the NEXT100 detector, a high-pressure xenon gas TPC that will search for the neutrinoless double beta decay of $^{136}$Xe. X-ray energy depositions produced by the de-excitation of Xenon atoms after the interaction of gamma rays from radioactive sources have been used to characterize the response of the detector obtaining the spatial calibration needed for close-to-optimal energy resolution. Our result, 5.5% FWHM at 30 keV, extrapolates to 0.6% FWHM at the Q value of $^{136}$Xe. Additionally, alpha decays from radon have been used to measure several detection properties and parameters of xenon gas such as electron-ion recombination, electron drift velocity, diffusion and primary scintillation light yield. Alpha spectroscopy is also used to quantify the activity of radon inside the detector, a potential source of background for most double beta decay experiments.

  7. WHY SEARCH FOR DOUBLE BETA DECAY?

    E-Print Network [OSTI]

    Kayser, B.

    2010-01-01T23:59:59.000Z

    the search for neutrinoless double beta decay may prove verySearching for neutrinoless double beta decay is the onlysensitivity of neutrinoless double beta decay. The potential

  8. High gas flow alpha detector

    DOE Patents [OSTI]

    Bolton, R.D.; Bounds, J.A.; Rawool-Sullivan, M.W.

    1996-05-07T23:59:59.000Z

    An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors. 4 figs.

  9. High gas flow alpha detector

    DOE Patents [OSTI]

    Bolton, Richard D. (Los Alamos, NM); Bounds, John A. (Los Alamos, NM); Rawool-Sullivan, Mohini W. (Los Alamos, NM)

    1996-01-01T23:59:59.000Z

    An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors.

  10. Alpha Technologies | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat Place: Wayne,Energy Information Jump to:Alpha Energy

  11. Cosmology with decaying particles

    SciTech Connect (OSTI)

    Turner, M.S.

    1984-09-01T23:59:59.000Z

    We consider a cosmological model in which an unstable massive relic particle species (denoted by X) has an initial mass density relative to baryons ..beta../sup -1/ identically equal rho/sub X//rho/sub B/ >> 1, and then decays recently (redshift z less than or equal to 1000) into particles which are still relativistic today (denoted by R). We write down and solve the coupled equations for the cosmic scale factor a(t), the energy density in the various components (rho/sub X/, rho/sub R/, rho/sub B/), and the growth of linear density perturbations (delta rho/rho). The solutions form a one parameter (..beta..) family of solutions; physically ..beta../sup -1/ approx. = (..cap omega../sub R//..cap omega../sub NR/) x (1 + z/sub D/) = (ratio today of energy density of relativistic to nonrelativistic particles) x (1 + redshift of (decay)). We discuss the observational implications of such a cosmological model and compare our results to earlier results computed in the simultaneous decay approximation. In an appendix we briefly consider the case where one of the decay products of the X is massive and becomes nonrelativistic by the present epoch. 21 references.

  12. Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Heinrich Päs; Werner Rodejohann

    2015-07-01T23:59:59.000Z

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  13. Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Päs, Heinrich

    2015-01-01T23:59:59.000Z

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  14. Vacuum Energy Decay

    E-Print Network [OSTI]

    Enrique Álvarez; Roberto Vidal

    2011-11-09T23:59:59.000Z

    The problem of the vacuum energy decay is studied through the analysis of the vacuum survival amplitude ${\\mathcal A}(z, z')$. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior is discussed up to first order in the coupling constant, $\\l$.

  15. Neutrinoless double beta decay

    E-Print Network [OSTI]

    Petr Vogel

    2006-11-17T23:59:59.000Z

    The status of the search for neutrinoless double beta decay is reviewed. The effort to reach the sensitivity needed to cover the effective Majorana neutrino mass corresponding to the degenerate and inverted mass hierarchy is described. Various issues concerning the theory (and phenomenology) of the relation between the $0\

  16. Millisecond Oxidation of Alkanes

    Broader source: Energy.gov [DOE]

    This factsheet describes a project whose goal is to commercialize a production process for propylene and acrylic acid from propane using a catalytic auto-thermal oxydehydrogenation process operating at short contact times. Auto-thermal oxidation for conversion of propane to propylene and acrylic acid promises energy savings of 20 trillion Btu per year by 2020. In addition to reducing energy consumption, this technology can reduce manufacturing costs by up to 25 percent, and reduce a variety of greenhouse gas emissions.

  17. Local Varying-Alpha Theories

    E-Print Network [OSTI]

    John D. Barrow; Joao Magueijo

    2015-01-30T23:59:59.000Z

    In a recent paper we demonstrated how the simplest model for varying alpha may be interpreted as the effect of a dielectric material, generalized to be consistent with Lorentz invariance. Unlike normal dielectrics, such a medium cannot change the speed of light, and its dynamics obey a Klein-Gordon equation. This work immediately suggests an extension of the standard theory, even if we require compliance with Lorentz invariance. Instead of a wave equation, the dynamics may satisfy a local algebraic relation involving the permittivity and the properties of the electromagnetic field, in analogy with more conventional dielectric (but still preserving Lorentz invariance). We develop the formalism for such theories and investigate some phenomenological implications. The problem of the divergence of the classical self-energy can be solved, or at least softened, in this framework. Some interesting new cosmological solutions for the very early universe are found, including the possibility of a bounce, inflation and expansion with a loitering phase, all of which are induced by early variations in alpha.

  18. Beta/alpha continuous air monitor

    DOE Patents [OSTI]

    Becker, Gregory K. (Idaho Falls, ID); Martz, Dowell E. (Grand Junction, CO)

    1989-01-01T23:59:59.000Z

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinguishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts.

  19. Beta/alpha continuous air monitor

    DOE Patents [OSTI]

    Becker, G.K.; Martz, D.E.

    1988-06-27T23:59:59.000Z

    A single deep layer silicon detector in combination with a microcomputer, recording both alpha and beta activity and the energy of each pulse, distinquishing energy peaks using a novel curve fitting technique to reduce the natural alpha counts in the energy region where plutonium and other transuranic alpha emitters are present, and using a novel algorithm to strip out radon daughter contribution to actual beta counts. 7 figs.

  20. Inclusive J/{psi} Production in {Upsilon} Decay Via Color-Singlet Mechanism

    SciTech Connect (OSTI)

    He Zhiguo [Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918(4), Beijing, 100049 (China) and Theoretical Physics Center for Science Facilities, (CAS) Beijing, 100049 (China); Departament d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, Diagonal, 647, E-08028 Barcelona, Catalonia (Spain); Wang Jianxiong [Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918(4), Beijing, 100049 (China) and Theoretical Physics Center for Science Facilities, (CAS) Beijing, 100049 (China)

    2011-05-23T23:59:59.000Z

    We report the recent works about the inclusive J/{psi} production in {Upsilon} decay. Our results show that until now the color-singlet (CS) contribution which includes leading order ({alpha}{sub s}{sup 5}){Upsilon}{yields}J/{psi}+cc-barg process and {alpha}{sub s}{sup 6} order {Upsilon}{yields}J/{psi}+gg(4g) process as well as {alpha}{sub s}{sup 2{alpha}2} order {Upsilon}{yields}J/{psi}+cc-bar and {Upsilon}{yields}J/{psi}+gg processes can not explain the experimental data yet. A preliminary CS prediction of R{sub cc} (B({Upsilon}{yields}J/{psi}+cc-bar+X)/B({Upsilon}{yields}J/{psi}+X)) 0.39{sub -0.20}{sup +0.21}, which is much larger than color-octet (CO) prediction, is also given as a good quantity to discriminate the CS and color-octet mechanism.

  1. BRIGHT 'MERGER-NOVA' FROM THE REMNANT OF A NEUTRON STAR BINARY MERGER: A SIGNATURE OF A NEWLY BORN, MASSIVE, MILLISECOND MAGNETAR

    SciTech Connect (OSTI)

    Yu, Yun-Wei [Institute of Astrophysics, Central China Normal University, Wuhan 430079 (China)] [Institute of Astrophysics, Central China Normal University, Wuhan 430079 (China); Zhang, Bing; Gao, He, E-mail: yuyw@mail.ccnu.edu.cn, E-mail: zhang@physics.unlv.edu [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States)] [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States)

    2013-10-20T23:59:59.000Z

    A massive millisecond magnetar may survive the merger of a neutron star (NS) binary, which would continuously power the merger ejecta. We develop a generic dynamic model for the merger ejecta with energy injection from the central magnetar. The ejecta emission (the {sup m}erger-nova{sup )} powered by the magnetar peaks in the UV band and the peak of the light curve, progressively shifts to an earlier epoch with increasing frequency. A magnetar-powered merger-nova could have an optical peak brightness comparable to a supernova, which is a few tens or hundreds times brighter than the radioactive-powered merger-novae (the so-called macro-nova or kilo-nova). On the other hand, such a merger-nova would peak earlier and have a significantly shorter duration than that of a supernova. An early collapse of the magnetar could suppress the brightness of the optical emission and shorten its duration. Such millisecond-magnetar-powered merger-novae may be detected from NS-NS merger events without an observed short gamma-ray burst, and could be a bright electromagnetic counterpart for gravitational wave bursts due to NS-NS mergers. If detected, it suggests that the merger leaves behind a massive NS, which has important implications for the equation-of-state of nuclear matter.

  2. Prospects for alpha particle studies on TFTR

    SciTech Connect (OSTI)

    Zweben, S.J.

    1987-05-01T23:59:59.000Z

    TFTR is expected to produce approximately 5 MW of alpha heating during the D/T Q approx. = 1 phase of operation in 1990. At that point the collective confinement properties and the heating effects of alpha particles become accessible for study for the first time. This paper outlines the potential performance of TFTR with respect to alpha particle production, the diagnostics which will be available for alpha particle measurements, and the physics issues which can be studied both before and during D/T operation.

  3. SHOE V.1.5 ALPHA

    Energy Science and Technology Software Center (OSTI)

    002913MLTPL00 Sandia Higher Order Elements (SHOE) v 0.5 alpha  http://midas3.kitware.com/midas/folder/10328 

  4. DESIGN AND PERFORMANCE OF A PASSIVE RADON DECAY PRODUCTS MONITOR

    E-Print Network [OSTI]

    F. Stieff

    2006-01-01T23:59:59.000Z

    Electret-based passive air samplers have been used in United Kingdom and elsewhere for quantitative sampling for airborne dust. Alpha electret ion chambers (EIC) have been used for quantitative measurement of deposited alpha emitting isotopes. These two well documented principles are combined to create a passive radon progeny monitor. Large area (50 cm2) electret charged to 500 to 2000 volts collect airborne radon decay products and the collected sample is "viewed " and measured by an alpha EIC. Such collection and measurement continues for the entire period of sampling, providing an integrated signal to the electret in alpha EIC. The present work is of exploratory nature and provides the responses of three different sizes of collection electrets. Results are also compared with a simple passive device with no collecting electret. The study provides data for optimization of the design depending upon the requirement. Study is limited to a typical home with equilibrium ratios from 40 to 60%. This method can be used for both short term and long term monitoring of RDP in working level units.

  5. Higgs boson decay into b-quarks at NNLO accuracy

    E-Print Network [OSTI]

    Del Duca, Vittorio; Somogyi, Gabor; Tramontano, Francesco; Trocsanyi, Zoltan

    2015-01-01T23:59:59.000Z

    We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.

  6. alpha(s) Determinations from Jets and Scaling Violations at HERA

    E-Print Network [OSTI]

    Thomas Kluge

    2006-10-13T23:59:59.000Z

    A review is given on recent alpha(s) determinations from the H1 and ZEUS Collaborations. These are based on measurements of jet cross sections, event shape variables, as well as on the observed scaling violation of the structure function F_2. A HERA average on alpha(s)(m_Z) is presented, in comparison with world mean values.

  7. Fast Proton Decay

    E-Print Network [OSTI]

    Tianjun Li; Dimitri V. Nanopoulos; Joel W. Walker

    2010-09-10T23:59:59.000Z

    We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \\to e^+ \\pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the most plausible parameter space within reach of the future Hyper-Kamiokande and DUSEL experiments. Because the TeV-scale vector-like particles can be produced at the LHC, we predict a strong correlation between the most exciting particle physics experiments of the coming decade.

  8. Double Beta Decay Experiments

    SciTech Connect (OSTI)

    Nanal, Vandana [Dept. of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India)

    2011-11-23T23:59:59.000Z

    At present, neutrinoless double beta decay is perhaps the only experiment that can tell us whether the neutrino is a Dirac or a Majorana particle. Given the significance of the 0{nu}{beta}{beta}, there is a widespread interest for these rare event studies employing a variety of novel techniques. This paper describes the current status of DBD experiments. The Indian effort for an underground NDBD experiment at the upcoming INO laboratory is also presented.

  9. X-raying Extended emission and rapid decay of short gamma-ray bursts

    E-Print Network [OSTI]

    Kagawa, Yasuaki; Sawano, Tatsuya; Toyanago, Asuka; Nakamura, Takashi; Takahashi, Keitaro; Kashiyama, Kazumi; Ioka, Kunihito

    2015-01-01T23:59:59.000Z

    Extended emission is a mystery in short gamma-ray bursts (SGRBs). By making time resolved spectral analyses of brightest eight events observed by {\\it Swift} XRT, we obviously classify the early X-ray emission of SGRBs into two types. One is the extended emission with exponentially rapid decay, which shows significant spectral softening during hundreds seconds since the SGRB trigger and is also detected by {\\it Swift}-BAT. The other is a dim afterglow only showing power-law decay over $10^4$ s. The correlations between the temporal decay and spectral indices of the extended emissions are inconsistent with the $\\alpha$-$\\beta$ correlation expected for the high-latitude curvature emission from a uniform jet. The observed too-rapid decay suggests the emission from a photosphere or a patchy surface, and manifests the stopping central engine via such as magnetic reconnection at the black hole.

  10. alpha inducido por: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 5 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  11. alpha pparalpha protects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 6 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  12. alpha autoradiography: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 6 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  13. alpha device: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  14. alpha dosimetry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  15. alpha kaudu transleeritavatest: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  16. alpha muzka ostajotsja: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  17. alpha particle physics: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    towards an alpha product state. It is shown that single alpha particle orbits in condensates of different nuclei are almost the same. It is thus argued that alpha particle...

  18. Dark decay of Top quark

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kong, Kyoungchui; Lee, Hye-Sung; Park, Myeonhun

    2014-04-01T23:59:59.000Z

    We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant topmore »quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.« less

  19. Dark decay of Top quark

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kong, Kyoungchui [Kansas; Lee, Hye-Sung [W&M, JLAB; Park, Myeonhun [Tokyo

    2014-04-01T23:59:59.000Z

    We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 ? deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t ? b W + Z's. This is the same as the dominant top quark decay (t ? b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.

  20. The formation and decay of superheavy nuclei produced in $^{48}Ca$-induced reactions

    E-Print Network [OSTI]

    Sushil Kumar; M. Balasubramaniam; Raj K. Gupta; G. Munzenberg; W. Scheid

    2011-11-08T23:59:59.000Z

    The formation of superheavy nuclei in $^{48}Ca+^{232}Th$, $^{238}U$, $^{242,244}Pu$ and $^{248}Cm$ reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT based preformed cluster-decay model (PCM) of Gupta and collaborators. According to QMFT, all these $^{48}Ca$-induced reactions are cold fusion reactions with relative excitation energies larger than for the $Pb$-induced cold fusion reactions and smaller than for the lighter beam i.e. $Mg$, $Si$ or $S$-induced hot fusion reactions. The same reactions were first suggested by Gupta et al. in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z=110 to 116, $^{50}Ca$ is shown to be a better beam for cold fusion, but $^{50}Ca$ is a radioactive nucleus. The $\\alpha$-decay half-lives of these nuclei after 3n and/ or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with experiments published by Dubna group and another recent calculation. As expected for such rare decays, PCM calculations show that the $\\alpha$-preformation factors are small, $\\sim 10^{-8}$ to $10^{-10}$. The possible competition of $\\alpha$-decays with heavy cluster emissions from these superheavy nuclei is also probed from the point of view of searching for new nuclear structure information and possible future experiments with such exotic nuclei. The decay half-lives for some clusters are in fact shown to be lower than the limits of experiments for nuclei with enough available atoms.

  1. Radiative ?(1S) decays

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-03-01T23:59:59.000Z

    — wW~ ii~ ~ + v~ 1''&WV'' V 0.20 0.45 0.70 ~y ~ EBFA~ 0.95 l.20 FIG. 4. Energy spectrum (normalized to beam energy) for Y~y2(h+h ) event candidates, with continuum data and ex- pected background from Y~m 2(h +h ) overplotted. 40 30— ~ 20— LLI IO— hl...PHYSICAL REVIEW 0 VOLUME 41, NUMBER 5 Radiative T(lS) decays 1 MARCH 1990 R. Fulton, M. Hempstead, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, and J. Whitmore Ohio State University, Columbus, Ohio 43210 W.-Y. Chen, J. Dominick, R. L. Mc...

  2. Rare B Decays

    SciTech Connect (OSTI)

    Jackson, P.D.; /Victoria U.

    2006-02-24T23:59:59.000Z

    Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.

  3. Reexamining charmless B\\to PV decays in QCD factorization approach

    E-Print Network [OSTI]

    Xinqiang Li; Yadong Yang

    2006-06-12T23:59:59.000Z

    Using the QCD factorization approach, we reexamine the two-body hadronic charmless $B$-meson decays to final states involving a pseudoscalar~($P$) and a vector~($V$) meson, with inclusion of the penguin contractions of spectator-scattering amplitudes induced by the $b\\to D g^\\ast g^\\ast$~(where $D=d$ or $s$, and $g^\\ast$ denotes an off-shell gluon) transitions, which are of order $\\alpha_s^2$. Their impacts on the CP-averaged branching ratios and CP-violating asymmetries are examined. We find that these higher order penguin contraction contributions have significant impacts on some specific decay modes. Since $B\\to \\pi K^{\\ast}$, $K \\rho$ decays involve the same electro-weak physics as $B\\to \\pi K$ puzzles, we present a detailed analysis of these decays and find that the five R-ratios for $B\\to \\pi K^{\\ast}$, $K \\rho$ system are in agreement with experimental data except for $R(\\pi K^*)$. Generally, these new contributions are found to be important for penguin-dominated $B\\to PV$ decays.

  4. alpha energy measurements: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with ATLAS Jet Production Measurements. CERN Preprints Summary: An inclusive jet multiplicity ratio is sensitive to the strong coupling constant, alphaS and has reduced...

  5. alpha continuous air: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    HEP - Experiment (arXiv) Summary: We present a review of measurements of alphaS. The individual measurements are discussed and intermediate averages for classes of related...

  6. CRAD, Quality Assurance - Oak Ridge National Laboratory TRU ALPHA...

    Broader source: Energy.gov (indexed) [DOE]

    Quality Assurance - Oak Ridge National Laboratory TRU ALPHA LLWT Project CRAD, Quality Assurance - Oak Ridge National Laboratory TRU ALPHA LLWT Project November 2003 A section of...

  7. SUMOylation of ROR{alpha} potentiates transcriptional activation function

    SciTech Connect (OSTI)

    Hwang, Eun Ju [Department of Biological Sciences, Research Center for Women's Disease, Sookmyung Women's University, 52 Hyochangwon-gil, Yongsan-gu, Seoul 140-742 (Korea, Republic of); Lee, Ji Min [Department of Biological Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Jeong, Jiyeong; Park, Joo Hyeon; Yang, Young; Lim, Jong-Seok [Department of Biological Sciences, Research Center for Women's Disease, Sookmyung Women's University, 52 Hyochangwon-gil, Yongsan-gu, Seoul 140-742 (Korea, Republic of); Kim, Jung Hwa [Department of Medical Sciences, Inha University, Incheon 402-751 (Korea, Republic of); Baek, Sung Hee [Department of Biological Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Keun Il [Department of Biological Sciences, Research Center for Women's Disease, Sookmyung Women's University, 52 Hyochangwon-gil, Yongsan-gu, Seoul 140-742 (Korea, Republic of)], E-mail: kikim@sookmyung.ac.kr

    2009-01-16T23:59:59.000Z

    SUMOylation regulates a variety of cellular processes, including control of transcriptional activities of nuclear receptors. Here, we present SUMOylation of orphan nuclear receptor, ROR{alpha} by both SUMO-1 and SUMO-2. SUMOylation of ROR{alpha} occurred on the 240th lysine residue at the hinge region of human protein. PIAS family members, PIASx{alpha}, PIAS3, and PIASy, increased SUMOylation of ROR{alpha}, whereas SENP2 specifically removed SUMO from ROR{alpha}. SUMOylation-defective mutant form of ROR{alpha} exhibited decreased transcriptional activity on ROR{alpha}-responsive promoters indicating that SUMOylation may positively regulate transcriptional function of ROR{alpha}.

  8. alpha magnetic spectrometer: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    23 24 25 Next Page Last Page Topic Index 1 Testing and Final Construction of the Superconducting Magnet for the Alpha Magnetic Spectrometer MIT - DSpace Summary: The Alpha...

  9. Study of the [beta]-delayed neutron decay of [sup 18]N

    SciTech Connect (OSTI)

    Scheller, K.W.; Goerres, J.; Ross, J.G.; Wiescher, M. (Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)); Harkewicz, R.; Morrissey, D.J. (National Superconducting Cyclotron Laboratory and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)); Sherrill, B.M.; Steiner, M. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)); Orr, N.A.; Winger, J.A. (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States))

    1994-01-01T23:59:59.000Z

    The [beta]-delayed neutron decay of [sup 18]N has been studied using a time-of-flight array with high efficiency. The [sup 18]N ions were produced by fragmentation of a [ital E]/[ital A]=75 MeV [sup 22]Ne beam. Transitions to nine neutron unbound states have been observed with a total branching ratio of 2.2[plus minus]0.4%. The results are compared with measurements of the decay to [gamma]- and [alpha]-emitting states and the differences between the present results and a recent measurement of the [ital P][sub [ital n

  10. Screening materials with the XIA UltraLo alpha particle counter at Southern Methodist University

    SciTech Connect (OSTI)

    Nakib, M. Z.; Cooley, J.; Kara, B.; Qiu, H.; Scorza, S. [Department of Physics, Southern Methodist University, Dallas, TX (United States)] [Department of Physics, Southern Methodist University, Dallas, TX (United States); Guiseppe, V. E. [Department of Physics, University of South Dakota, Vermillion, SD (United States)] [Department of Physics, University of South Dakota, Vermillion, SD (United States); Rielage, K. [Los Alamos National Laboratory, Los Alamos, NM (United States)] [Los Alamos National Laboratory, Los Alamos, NM (United States); Schnee, R. W. [Department of Physics, Syracuse University, Syracuse, NY (United States)] [Department of Physics, Syracuse University, Syracuse, NY (United States)

    2013-08-08T23:59:59.000Z

    Southern Methodist University houses one of five existing commercially available UltraLo 1800 production model alpha counters made by XIA LLC. The instrument has an electron drift chamber with a 707 cm{sup 2} or 1800 cm{sup 2} counting region which is determined by selecting the inner electrode size. The SMU team operating this device is part of the SuperCDMS screening working group, and uses the alpha counter to study the background rates from the decay of radon in materials used to construct the SuperCDMS experiment. We have studied four acrylic samples obtained from the MiniCLEAN direct dark matter search with the XIA instrument demonstrating its utility in low background experiments by investigating the plate-out of {sup 210}Pb and comparing the effectiveness of cleaning procedures in removing {sup 222}Rn progenies from the samples.

  11. Artificial Alpha-Active Bismuth Isotopes

    E-Print Network [OSTI]

    Templeton, D.H.

    2010-01-01T23:59:59.000Z

    Laboratory Contract No. W-7405-eng-48 ARTIFICIAL ALPHA-thD." 203. Contract No. W-7405-eng-48 To be published as awith the Atom~c N~mber W~7405- eng-48 Enerp:y Commission in

  12. NEW APPROACHES TO CONFINED ALPHA DIAGNOSTICS

    SciTech Connect (OSTI)

    FISHER,R.K

    2004-04-01T23:59:59.000Z

    Three new approaches to obtain information on the confined fast alphas in International Thermonuclear Experimental Reactor (ITER) are proposed. The first technique measures the energetic charge exchange (CX) neutrals that result from the alpha collision-induced knock-on fuel ion tails undergoing electron capture on the MeV D neutral beams planned for heating and current drive. The second technique measures the energetic knock-on neutron tail due to alphas using the lengths of the proton recoil tracks produced by neutron collisions in nuclear emulsions. The range of the 14 to 20 MeV recoil protons increases by {approx}140 microns per MeV. The third approach would measure the CX helium neutrals resulting from confined alphas capturing two electrons in the ablation cloud surrounding a dense gas jet that has been proposed for disruption mitigation in ITER.

  13. Approaches to confined alpha diagnostics on ITER

    SciTech Connect (OSTI)

    Fisher, R.K. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States)

    2004-10-01T23:59:59.000Z

    Three approaches to obtain information on the confined fast alphas in the International Thermonuclear Experimental Reactor (ITER) are proposed. The first technique measures the energetic charge exchange (CX) neutrals that result from the alpha collision-induced knock-on fuel ion tails undergoing electron capture on the MeV D neutral beams planned for heating and current drive. The second technique measures the energetic knock-on neutron tail due to alphas using the lengths of the proton recoil tracks produced by neutron collisions in nuclear emulsions. The range of the 14 to 20 MeV recoil protons increases by {approx}140 {mu}m per MeV. The third approach would measure the CX helium neutrals resulting from confined alphas capturing two electrons in the ablation cloud surrounding a dense gas jet that has been proposed for disruption mitigation in ITER.

  14. Nuclear diagnostic for fast alpha particles

    DOE Patents [OSTI]

    Grisham, L.R.; Post, D.E. Jr.; Dawson, J.M.

    1983-11-23T23:59:59.000Z

    This invention relates generally to high energy confined plasmas and more particularly is directed to measuring the velocity distribution of confined energetic alpha particles resulting from deuterium-tritium fusion reactions in a confined energetic plasma.

  15. Transport of Radioactive Material by Alpha Recoil

    SciTech Connect (OSTI)

    Icenhour, A.S.

    2005-05-19T23:59:59.000Z

    The movement of high-specific-activity radioactive particles (i.e., alpha recoil) has been observed and studied since the early 1900s. These studies have been motivated by concerns about containment of radioactivity and the protection of human health. Additionally, studies have investigated the potential advantage of alpha recoil to effect separations of various isotopes. This report provides a review of the observations and results of a number of the studies.

  16. NSAC Subcommittee Double Beta Decay

    E-Print Network [OSTI]

    and Lawrence Berkeley National Laboratory #12;2 Decay #12;2 0 0 Decay If 0 occurs then the neutrino is a Majorana particle and the neutrino and antiparticle are not distinct. Lepton number is not conserved! #12 30 ) Experimental Resolution #12;Higgs Boson, Majorana Mass and Lepton Number Conservation #12;LVD

  17. Methods for the synthesis and polymerization of .alpha.,.alpha.'-dihalo-p-xylenes

    DOE Patents [OSTI]

    Ferraris, John P. (Coppell, TX); Neef, Charles J. (Garland, TX)

    2002-07-30T23:59:59.000Z

    The present invention describes an improved method for the polymerization of .alpha.,.alpha.-dihalo-p-xylene's such as the .alpha.,.alpha.'-dihalo-2-methoxy-5-(2-ethylhexyloxy)-xylene's. The procedure for synthesis is based on the specific order of addition of reagents and the use of an anionic initiator that allows control of the molecular weight of the polymer. The molecular weight control allows processability of the polymer which is important for its utility in applications including in light-emitting-diodes, field effect transistors and photovoltaic devices.

  18. Particle decay in false vacuum

    SciTech Connect (OSTI)

    Gorsky, A.; Voloshin, M. B. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Institute of Theoretical and Experimental Physics, Moscow, 117259 (Russian Federation)

    2006-01-15T23:59:59.000Z

    We revisit the problem of decay of a metastable vacuum induced by the presence of a particle. For the bosons of the 'master field' the problem is solved in any number of dimensions in terms of the spontaneous decay rate of the false vacuum, while for a fermion we find a closed expression for the decay rate in (1+1) dimensions. It is shown that in the (1+1) dimensional case an infrared problem of one-loop correction to the decay rate of a boson is resolved due to a cancellation between soft modes of the field. We also find the boson decay rate in the 'sine-Gordon staircase' model in the limits of strong and weak coupling.

  19. Particle decay in false vacuum

    E-Print Network [OSTI]

    A. Gorsky; M. B. Voloshin

    2005-11-08T23:59:59.000Z

    We revisit the problem of decay of a metastable vacuum induced by the presence of a particle. For the bosons of the `master field' the problem is solved in any number of dimensions in terms of the spontaneous decay rate of the false vacuum, while for a fermion we find a closed expression for the decay rate in (1+1) dimensions. It is shown that in the (1+1) dimensional case an infrared problem of one-loop correction to the decay rate of a boson is resolved due to a cancellation between soft modes of the field. We also find the boson decay rate in the `sine-Gordon staircase' model in the limits of strong and weak coupling.

  20. Search for neutrinoless decays of the ? lepton

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-02-01T23:59:59.000Z

    We have searched for neutrinoless ? decays into three charged particles. Evidence of such decays would demonstrate nonconservation of lepton flavor and, in some cases, lepton number. We see no signal for any such neutrinoless ? decays and set upper...

  1. Proton Decay and the Planck Scale

    E-Print Network [OSTI]

    Larson, Daniel T.

    2009-01-01T23:59:59.000Z

    LBNL- 56556 PROTON DECAY AND THE PLANCK SCALE DANIEL T.ph/0410035v1 2 Oct 2004 PROTON DECAY AND THE PLANCK SCALE ?without grand uni?cation, proton decay can be a powerful

  2. High-energy electrons from the muon decay in orbit: radiative corrections

    E-Print Network [OSTI]

    Szafron, Robert

    2015-01-01T23:59:59.000Z

    We determine the $\\mathcal{O}(\\alpha)$ correction to the energy spectrum of electrons produced in the decay of muons bound in atoms. We focus on the high-energy end of the spectrum that constitutes a background for the muon-electron conversion and will be precisely measured by the upcoming experiments Mu2e and COMET. The correction suppresses the background by about 20\\%.

  3. $?$ Meson In $J/?$ Decays

    E-Print Network [OSTI]

    Wujun Huo; Xinmin Zhang; Tao Huang

    2002-03-20T23:59:59.000Z

    Recently BES at BEPC found evidence for the existence of the $\\sigma$ meson in the process of $J/\\Psi \\to \\sigma\\omega \\to\\pi\\pi\\omega$. In this paper we firstly discuss the relevant coupling $g_{\\sigma\\pi\\pi}$ and show that the linear $\\sigma$ model gives rise to a reasonable description of the $\\sigma$ decay into $\\pi$'s, then we calculate the coupling constant $g^{th}_{J/\\Psi\\sigma\\omega}$ by using the perturbative QCD technique and the light-cone wave functions of the $\\sigma$ and $\\omega$ mesons. The results show that the theoretical value of $g^{th}_{J/\\Psi\\sigma\\omega}$ is within the range of experimental value $g_{J/\\Psi\\sigma\\omega}$.

  4. Metastable and charged particle decay in neon afterglow studied by the breakdown time delay measurements

    SciTech Connect (OSTI)

    Markovic, V. Lj.; Gocic, S. R.; Stamenkovic, S. N.; Petrovic, Z. Lj. [Department of Physics, University of Nis, P.O. Box 224, 18001 Nis (Serbia); Institute of Physics, P.O. Box 68, 11000 Belgrade (Serbia and Montenegro)

    2007-10-15T23:59:59.000Z

    Memory effect--the long time variation of the electrical breakdown time delay on the relaxation time t{sub d}({tau}) in neon--was explained by the Ne({sup 3}P{sub 2}) (1s{sub 5}) metastable state remaining from the preceding glow [Dj. A. Bosan, M. K. Radovic, and Dj. M. Krmpotic, J. Phys. D 19, 2343 (1986)]. However, the authors neglected the quenching processes that reduce the effective lifetime of metastable states several orders of magnitude below that of the memory effect observations. In this paper the time delay measurements were carried out in neon at the pressure of 6.6 mbar in a gas tube with gold-plated copper cathode, and the approximate and exact numerical models are developed in order to study the metastable and charged particle decay in afterglow. It was found that the metastable hypothesis completely failed to explain the afterglow kinetics, which is governed by the decay of molecular neon ions and molecular nitrogen ions produced in Ne{sub 2}{sup +} collisions with nitrogen impurities; i.e., Ne{sub 2}{sup +}+N{sub 2}{yields}N{sub 2}{sup +}+2Ne. Charged particle decay is followed up to hundreds of milliseconds in afterglow, from ambipolar to the free diffusion limit. After that, the late afterglow kinetics in neon can be explained by the nitrogen atoms recombining on the cathode surface and providing secondary electrons that determine the breakdown time delay down to the cosmic rays and natural radioactivity level.

  5. ALPHA-PARTICLE RADIOBIOLOGICAL EXPERIMENTS USING THIN CR-39 DETECTORS

    E-Print Network [OSTI]

    Yu, K.N.

    . INTRODUCTION Alpha particles from inhaled radon progeny are the most important source of irradiation

  6. Mass predictions of superheavy nuclei from the systematics of $?$-Decay Energies

    E-Print Network [OSTI]

    Z. Li; B. Sun; C. H. Shen; W. Zuo

    2014-08-29T23:59:59.000Z

    A recent proposed method for $\\alpha$-decay energies ($Q_\\alpha$) [J.M. Dong, W. Zuo, and W. Scheid, Phys. Rev. Lett. \\textbf{107}, 012501 (2011)] can reproduce experimental data of superheavy nuclei (SHN) with an $rms$-value of less than 100 keV. However, a sinusoid-like periodic deviation from experiments, which limits the accuracy in predictions, is observed when using different reference nuclei. In this paper, we have further extended this hybrid method, i.e., to predict $Q_\\alpha$ of the as-yet-unobserved SHN with the help of known nuclei. It is found that the systematic deviation in previous study is rooted in the nuclear mass model employed. By further analyzing the source of errors, different nuclear mass models are evaluated based on the same procedure.

  7. Atomic nuclei decay modes by spontaneous emission of heavy ions

    SciTech Connect (OSTI)

    Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.

    1985-08-01T23:59:59.000Z

    The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.

  8. Dynamical and sequential decay effects on isoscaling and density dependence of the symmetry energy

    E-Print Network [OSTI]

    W. D. Tian; Y. G. Ma; X. Z. Cai; D. Q. Fang; W. Guo; C. W. Ma; G. H. Liu; W. Q. Shen; Y. Shi; H. W. Wang; K. Wang; W. Xu; T. Z. Yan

    2006-01-25T23:59:59.000Z

    The isoscaling properties of the primary and final products are studied via isospin dependent quantum molecular dynamics (IQMD) model and the followed sequential decay model GEMINI, respectively. It is found that the isoscaling parameters $\\alpha$ of both primary and final products keep no significant change for light fragments, but increases with the mass for intermediate and heavy products. The dynamical effects on isoscaling are exhibited by that $\\alpha$ value decreases a little with the evolution time of the system, and opposite trend for the heavy products. The secondary decay effects on isoscaling are reflected in the increasing of the $\\alpha$ value for the final products which experiences secondary decay process. Furthermore the density dependence of the symmetry energy has also been explored, it is observed that in the low densities the symmetry energy coefficient has the form of $C_{sym}(\\rho)\\sim C_{0}(\\rho/\\rho_{0})^{\\gamma}$, where $\\gamma = 0.7 \\sim 1.3$ for both primary and final products, but $C_{0}$ have different values for primary and final products. It is also suggested that it might be more reasonable to describe the density dependence of the symmetry energy coefficient by the $C_{sym}(\\rho/\\rho_{0})\\approx C_{1}(\\rho/\\rho_{0})^{\\gamma_{soft}} + C_{2}(\\rho/\\rho_{0})^{\\gamma_{stiff}}$ with $\\gamma_{soft}\\leq 1$, $\\gamma_{stiff}\\geq 1$ and $C_{1}, C_{2}$ constant parameters.

  9. Alpha Channeling in Rotating Plasma with Stationary Waves

    SciTech Connect (OSTI)

    A. Fetterman and N.J. Fisch

    2010-02-15T23:59:59.000Z

    An extension of the alpha channeling effect to supersonically rotating mirrors shows that the rotation itself can be driven using alpha particle energy. Alpha channeling uses radiofrequency waves to remove alpha particles collisionlessly at low energy. We show that stationary magnetic fields with high n? can be used for this purpose, and simulations show that a large fraction of the alpha energy can be converted to rotation energy.

  10. On the Diffuse Lyman-alpha Halo Around Lyman-alpha Emitting Galaxies

    E-Print Network [OSTI]

    Lake, Ethan; Cen, Renyue; Sadoun, Raphael; Momose, Rieko; Ouchi, Masami

    2015-01-01T23:59:59.000Z

    Ly$\\alpha$ photons scattered by neutral hydrogen atoms in the circumgalactic media or produced in the halos of star-forming galaxies are expected to lead to extended Ly$\\alpha$ emission around galaxies. Such low surface brightness Ly$\\alpha$ halos (LAHs) have been detected by stacking Ly$\\alpha$ images of high-redshift star-forming galaxies. We study the origin of LAHs by performing radiative transfer modeling of nine $z=3.1$ Lyman-Alpha Emitters (LAEs) in a high resolution hydrodynamic galaxy formation simulation. We develop a method of computing the mean Ly$\\alpha$ surface brightness profile of each LAE by effectively integrating over many different observing directions. Without adjusting any parameters, our model yields an average Ly$\\alpha$ surface brightness profile in remarkable agreement with observations. We find that observed LAHs can not be accounted for solely by photons originating from the central LAE and scattered to large radii by hydrogen atoms in the circumgalactic gas. Instead, Ly$\\alpha$ em...

  11. COUPLED CHANNEL ALPHA DECAY THEORY FOR EVEN- AND ODD-MASS LIGHT AND HEAVY NUCLEI

    E-Print Network [OSTI]

    Rauscher, E.A.

    2011-01-01T23:59:59.000Z

    at the nuclear t surface to give agreement with experimentalnuclear wave functions are approximated by shell model wave functions and reasonable agreement

  12. Double beta decay: present status

    E-Print Network [OSTI]

    A. S. Barabash

    2008-07-18T23:59:59.000Z

    The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ beta decay experiments with a sensitivity for the $$ at the level of (0.01-0.1) eV are considered.

  13. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06T23:59:59.000Z

    We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

  14. $D_s^+ \\to ??^+$ Decay

    E-Print Network [OSTI]

    E. El aaoud

    1998-01-08T23:59:59.000Z

    Motivated by the experimental measurement of the decay rate, $\\Gamma$, and the longitudinal polarization, $P_L$, in the Cabibbo favored decay $D_s^+\\to \\phi {\\rho}^{+}$, we have studied theoretical prediction within the context of factorization approximation invoking several form factors models. We were able to obtain agreement with experiment for both $\\Gamma$ and $P_L$ by using experimentally measured values of the form factors $A_1^{D_s\\phi}(0)$, $A_2^{D_s\\phi}(0)$ and $V^{D_s\\phi}(0)$ in the semi-leptonic decay $D_s^+\\to \\phi l^{+}\

  15. Neutrinoless Double Beta Decay Constraints

    E-Print Network [OSTI]

    Hiroaki Sugiyama

    2003-07-25T23:59:59.000Z

    A brief overview is given of theoretical analyses with neutrinoless double beta decay experiments. Theoretical bounds on the ``observable'', _betabeta, are presented. By using experimental bounds on _betabeta, allowed regions are obtained on the m_l-cos{2theta_12} plane, where m_l stands for the lightest neutrino mass. It is shown that Majorana neutrinos can be excluded by combining possible results of future neutrinoless double beta decay and {}^3H beta decay experiments. A possibility to constrain one of two Majorana phases is discussed also.

  16. Computer code for double beta decay QRPA based calculations

    E-Print Network [OSTI]

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    . The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays

  17. Search for rare nuclear decays with HPGe detectors at the STELLA facility of the LNGS

    SciTech Connect (OSTI)

    Belli, P.; Di Marco, A. [INFN, Sezione di Roma Tor Vergata, Rome (Italy); Bernabei, R.; D'Angelo, S. [INFN, Sezione di Roma Tor Vergata, Rome, Italy and Dipartimento di Fisica, Università di Roma Tor Vergata, Rome (Italy); Cappella, F.; D'Angelo, A.; Incicchitti, A. [INFN, Sezione di Roma La Sapienza, Rome, Italy and Dipartimento di Fisica, Università di Roma La Sapienza, Rome (Italy); Cerulli, R.; Di Vacri, M. L.; Laubenstein, M.; Nisi, S. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Danevich, F. A.; Kobychev, V. V.; Poda, D. V.; Tretyak, V. I. [Institute for Nuclear Research, Kyiv (Ukraine); Kovtun, G. P.; Kovtun, N. G.; Shcherban, A. P.; Solopikhin, D. A. [Kharkiv Institute of Physics and Technology, Kharkiv (Ukraine); Polischuk, O. G. [INFN, Sezione di Roma La Sapienza, Rome, Italy and Institute for Nuclear Research, Kyiv (Ukraine); and others

    2013-12-30T23:59:59.000Z

    Results on the search for rare nuclear decays with the ultra low background facility STELLA at the LNGS using gamma ray spectrometry are presented. In particular, the best T{sub 1/2} limits were obtained for double beta processes in {sup 96}Ru and {sup 104}Ru. Several isotopes, which potentially decay through different 2? channels, including also possible resonant double electron captures, were investigated for the first time ({sup 156}Dy, {sup 158}Dy, {sup 184}Os, {sup 192}Os, {sup 190}Pt, {sup 198}Pt). Search for resonant absorption of solar {sup 7}Li axions in a LiF crystal gave the best limit for the mass of {sup 7}Li axions (< 8.6 keV). Rare alpha decay of {sup 190}Pt to the first excited level of {sup 186}Os(E{sub exc}?=?137.2keV) was observed for the first time.

  18. Synthesis of peptide .alpha.-thioesters

    DOE Patents [OSTI]

    Camarero, Julio A. (Livermore, CA); Mitchell, Alexander R. (Livermore, CA); De Yoreo, James J. (Clayton, CA)

    2008-08-19T23:59:59.000Z

    Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

  19. Alternating current long range alpha particle detector

    DOE Patents [OSTI]

    MacArthur, D.W.; McAtee, J.L.

    1993-02-16T23:59:59.000Z

    An alpha particle detector, utilizing alternating currents, which is capable of detecting alpha particles from distinct sources. The use of alternating currents allows use of simpler ac circuits which, in turn, are not susceptible to dc error components. It also allows the benefit of gas gain, if desired. In the invention, a voltage source creates an electric field between two conductive grids, and between the grids and a conductive enclosure. Air containing air ions created by collision with alpha particles is drawn into the enclosure and detected. In some embodiments, the air flow into the enclosure is interrupted, creating an alternating flow of ions. In another embodiment, a modulated voltage is applied to the grid, also modulating the detection of ions.

  20. Decoherence delays false vacuum decay

    E-Print Network [OSTI]

    Thomas C. Bachlechner

    2013-04-17T23:59:59.000Z

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling $\\Gamma\\sim\\Gamma_{CDL}^{2}$, where $\\Gamma_{CDL}$ is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincare recurrence in de Sitter space.

  1. The decay of hot nuclei

    SciTech Connect (OSTI)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01T23:59:59.000Z

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

  2. Neutrinoless Double Beta-Decay

    E-Print Network [OSTI]

    S. M. Bilenky

    2010-01-12T23:59:59.000Z

    The neutrinoless double $\\beta$-decay of nuclei is reviewed. We discuss neutrino mixing and 3x3 PMNS neutrino mixing matrix. Basic theory of neutrinoless double $\\beta$-decay is presented in some details. Results of different calculations of nuclear matrix element are discussed. Experimental situation is considered. The Appendix is dedicated to E. Majorana (brief biography and his paper in which the theory of Majorana particles is given)

  3. Beta and gamma decays April 9, 2002

    E-Print Network [OSTI]

    Landstreet, John D.

    Beta and gamma decays April 9, 2002 1 Simple Fermi theory of beta decay ² Beta decay is one by the emission of a positive or negative beta particle (positron or electron). To ensure conservation of lepton emitted in beta decay is a continuum of energies, up to a maximum value, with most emitted betas having

  4. Fan-less long range alpha detector

    DOE Patents [OSTI]

    MacArthur, D.W.; Bounds, J.A.

    1994-05-10T23:59:59.000Z

    A fan-less long range alpha detector is disclosed which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces. 2 figures.

  5. Signature of nonexponential nuclear decay

    E-Print Network [OSTI]

    A Ray; A K Sikdar; A De

    2015-03-18T23:59:59.000Z

    Precision tests of decay law of radioactive nuclei have not so far found any deviation from the exponential decay law at early time, as predicted by quantum mechanics. In this paper, we show that the quantum decoherence time (i.e. the timescale of nonexponential decay) of the quasifission or fission process should be of the order of attosecond considering the atom of the fissioning nucleus as a quantum detector. Hence, the observed decay timescale of the quasifission or fission process of even highly excited (EX greater than 50 MeV) transuranium and uraniumlike complexes should be rather long (of the order of attosecond) in spite of their very fast exponential decay timescale (of the order of zeptosecond) as measured by the nuclear techniques. Recent controversy regarding the observation of very long (of the order of attosecond ) and very short (of the order of zeptosecond ) quasifission or fission timescales for similar systems at similar excitation energies as obtained by direct techniques (crystal blocking, X ray fission fragment) and nuclear techniques could be interpreted as evidence for nonexponential decays in nuclear systems

  6. Mapping High-velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    E-Print Network [OSTI]

    France, Kevin; Fransson, Claes; Larsson, Josefin; Frank, Kari A; Burrows, David N; Challis, Peter; Kirshner, Robert P; Chevalier, Roger A; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01T23:59:59.000Z

    We present new {\\it Hubble Space Telescope} images of high-velocity H-$\\alpha$ and Lyman-$\\alpha$ emission in the outer debris of SN~1987A. The H-$\\alpha$ images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H$\\alpha$ imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals ($-$7,500~$<$~$V_{obs}$~$<$~$-$2,800 km s$^{-1}$) and (1,000~$<$~$V_{obs}$~$<$~7,500 km s$^{-1}$), $\\dot{M_{H}}$ = 1.2~$\\times$~10$^{-3}$ M$_{\\odot}$ yr$^{-1}$. We also present the first Lyman-$\\alpha$ imaging of the whole remnant and new $Chandra$ X-ray observations. Comparing the spatial distribution of the Lyman-$\\alpha$ and X-ray emission, we observe that the majority of the high-velocity Lyman-$\\alpha$ emission originates interior to the equatorial...

  7. Use of MCNPX for Alpha Spectrometry Simulations of a Continuous Air Monitor

    SciTech Connect (OSTI)

    Robert Hayes, Craig Marianno

    2007-01-01T23:59:59.000Z

    The purpose of this study was to determine if the alpha energy spectrum in a Passive Implanted Planar Silicon (PIPS) detector, as modeled by MCNPX [1], can be used to design a radon stripping algorithm for a continuous air monitor (CAM). This stripping algorithm would be employed to discriminate naturally occurring radioisotopes from the anthropogenic for nuclear safety -related applications. It is hoped that using an algorithm based on MCNPX simulations, the CAM will not be prone to false alarms when radon levels are dynamic as identified in other CAM systems [2,3]. This work is focused on the design of the next generation air particulate detector (NGAPD) for the United States Navy. The primary isotope of interest is Co-60. This radionuclide emits a beta with an average energy of 96 keV. Therefore, once deposited on the CAM filter, it will produce a beta continuum seen by the PIPS detector. In addition, as radon progeny is deposited on the air filter, these will give rise to characteristic alpha peaks and a beta continuum. This is primarily an issue in port-or land-based applications. Ultimately, measurement of a radon alpha spectrum is desired to predict the amount of beta activity which would be measured from the radon progeny decay chains. All excess beta activity could then be attributed to anthropogenic sources once the radon progeny contributions have been stripped out.

  8. Transformer Recharging with Alpha Channeling in Tokamaks

    SciTech Connect (OSTI)

    N.J. Fisch

    2009-12-21T23:59:59.000Z

    Transformer recharging with lower hybrid waves in tokamaks can give low average auxiliary power if the resistivity is kept high enough during the radio frequency (rf) recharging stage. At the same time, operation in the hot ion mode via alpha channeling increases the effective fusion reactivity. This paper will address the extent to which these two large cost saving steps are compatible. __________________________________________________

  9. Signature of nonexponential nuclear decay

    E-Print Network [OSTI]

    Ray, A; De, A

    2015-01-01T23:59:59.000Z

    Precision tests of decay law of radioactive nuclei have not so far found any deviation from the exponential decay law at early time, as predicted by quantum mechanics. In this paper, we show that the quantum decoherence time (i.e. the timescale of nonexponential decay) of the quasifission or fission process should be of the order of attosecond considering the atom of the fissioning nucleus as a quantum detector. Hence, the observed decay timescale of the quasifission or fission process of even highly excited (EX greater than 50 MeV) transuranium and uraniumlike complexes should be rather long (of the order of attosecond) in spite of their very fast exponential decay timescale (of the order of zeptosecond) as measured by the nuclear techniques. Recent controversy regarding the observation of very long (of the order of attosecond ) and very short (of the order of zeptosecond ) quasifission or fission timescales for similar systems at similar excitation energies as obtained by direct techniques (crystal blocking...

  10. Running alpha(s) from Landau-gauge gluon and ghost correlations

    E-Print Network [OSTI]

    A. Sternbeck; E. -M. Ilgenfritz; K. Maltman; M. Müller-Preussker; L. von Smekal; A. G. Williams

    2007-10-16T23:59:59.000Z

    We estimate the running coupling constant of the strong interactions within the nonperturbative framework of lattice QCD in Landau gauge. Our calculation is based on the ghost-gluon vertex which in the particular case of Landau gauge allows for a definition of alpha(s) in a MOM scheme solely in terms of the gluon and ghost dressing functions. As a first step we investigate the zero and two-flavour case and report here on preliminary results.

  11. Construction of Building 9201-1 (Alpha 1) - part 2

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2 Even while Building 9201-1 (Alpha 1) was being constructed, the first experimental Alpha unit (XAX) in Building 9731 successfully operated, after a week of start up efforts, on...

  12. Alpha phase precipitation from phase-separated beta phase in...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alpha phase precipitation from phase-separated beta phase in a model Ti-Mo-Al alloy studied by direct coupling of transmission Alpha phase precipitation from phase-separated beta...

  13. Study of alpha background in a dark matter detector

    E-Print Network [OSTI]

    Yegoryan, Hayk

    2010-01-01T23:59:59.000Z

    Alpha background, specifically from radon and its progeny in the uranium and thorium chains, has been a major issue in dark matter detectors. This work focuses on alpha background presence in the DMTPC experiment by examining ...

  14. alpha darbepoetine epo: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Phenomenology (arXiv) Summary: In the framework of nonrelativistic QCD, we compute the leading double-logarithmic corrections of order alphas3 ln2(1alphas) to the...

  15. alpha dinucleotide repeat: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Institute 12;www.rpi.edu Alpha Epsilon Lambda Alpha Sigma Chapter Co-terminal Honor Society Rensselaer Polytechnic Institute Chapter President Chaz Goodwine goodwc2@rpi.edu...

  16. Antibody-mediated reduction of {alpha}-ketoamides

    DOE Patents [OSTI]

    Schultz, P.G.; Gallop, M.A.

    1998-06-09T23:59:59.000Z

    Monoclonal antibodies raised against a 4-nitrophenyl phosphonate hapten catalyze the stereospecific reduction of an {alpha}-ketoamide to the corresponding {alpha}-hydroxyamide in the presence of an appropriate reducing agent.

  17. alpha particle emitting: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002-07-31 462 Angular momentum transport and proton-alpha differential streaming in the solar wind CERN Preprints Summary: The effect of solar rotation on the proton-alpha...

  18. alpha particles emitted: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002-07-31 462 Angular momentum transport and proton-alpha differential streaming in the solar wind CERN Preprints Summary: The effect of solar rotation on the proton-alpha...

  19. alpha particle counting: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Francesco Giudice; Ben Gripaios; Rakhi Mahbubani 2011-08-08 5 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  20. alpha particles progress: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  1. alpha particle diagnostics: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    kW, 140 GHz gyrotron tubes used with the Joint Egedal, Jan 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  2. alpha particle preformation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    output intensity of a Raman amplifier and the optimal 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  3. alpha particles: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  4. alpha particles biological effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    streams in interplanetary space. Bo Li; Xing Li 2006-06-07 8 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  5. alpha particles aberraciones: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  6. alpha particle analysis: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  7. alpha particle induced: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    F. L. Roman; V. Avrigeanu; W. von Oertzen 2008-08-05 7 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  8. alpha particles due: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  9. alpha particle transfer: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    their transferring energy to the wave. This could, in turn 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  10. alpha particle destabilization: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    their theoretical predictions 1,2, toroidicity-induced 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  11. alpha particle scattering: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    particle condensation. S. Ohkubo; Y. Hirabayashi 2011-02-11 5 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  12. alpha particle orbits: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  13. alpha particle effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    streams in interplanetary space. Bo Li; Xing Li 2006-06-07 8 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  14. alpha particles final: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  15. alpha particle spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    angles. Sergei P. Maydanyuk; Sergei V. Belchikov 2004-12-22 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  16. alpha particle radioimmunotherapy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in tissues (<100 micrometer) (more) Bck, Tom 2011-01-01 2 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  17. alpha particle diagnostic: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    kW, 140 GHz gyrotron tubes used with the Joint Egedal, Jan 3 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  18. alpha particle spectroscopy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Alpha-Particle Condensates Nuclear Experiment (arXiv) Summary: The alpha-particle condensate in nuclei is...

  19. alpha phase dipalmitoylphosphatidylcholine: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lyman Alpha Radiative Transfer in a Multi-Phase Medium Astrophysics (arXiv) Summary: Hydrogen Ly-alpha is our primary emission-line window into high redshift galaxies....

  20. Discussion of Alpha Particle Physics Issues for AT Burning Plasmas

    E-Print Network [OSTI]

    machines » Projections to burning plasma #12;Alpha self-heating in AT regimes v Production and control

  1. Thermodynamics of decaying vacuum cosmologies

    SciTech Connect (OSTI)

    Lima, J.A. [Physics Department, Brown University, Providence, Rhode Island 02912 (United States)] [Physics Department, Brown University, Providence, Rhode Island 02912 (United States); [Departamento de Fisica Teorica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN (Brazil)

    1996-08-01T23:59:59.000Z

    The thermodynamic behavior of decaying vacuum cosmologies is investigated within a manifestly covariant formulation. Such a process corresponds to a continuous, irreversible energy flow from the vacuum component to the created matter constituents. It is shown that if the specific entropy per particle remains constant during the process, the equilibrium relations are preserved. In particular, if the vacuum decays into photons, the energy density {rho} and average number density of photons {ital n} scale with the temperature as {rho}{approximately}{ital T}{sup 4} and {ital n}{approximately}{ital T}{sup 3}. The temperature law is determined and a generalized Planckian-type form of the spectrum, which is preserved in the course of the evolution, is also proposed. Some consequences of these results for decaying vacuum FRW-type cosmologies as well as for models with {open_quote}{open_quote}adiabatic{close_quote}{close_quote} photon creation are discussed. {copyright} {ital 1996 The American Physical Society.}

  2. Neutrinoless Double Beta Decay Experiments

    E-Print Network [OSTI]

    Garfagnini, Alberto

    2014-01-01T23:59:59.000Z

    Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been performed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future.

  3. Neutrinoless Double Beta Decay Experiments

    E-Print Network [OSTI]

    Alberto Garfagnini

    2014-08-11T23:59:59.000Z

    Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been performed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future.

  4. Predicting Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    M. Hirsch; Ernest Ma; J. W. F. Valle; A. Villanova del Moral

    2005-07-12T23:59:59.000Z

    We give predictions for the neutrinoless double beta decay rate in a simple variant of the A_4 family symmetry model. We show that there is a lower bound for the neutrinoless double beta decay amplitude even in the case of normal hierarchical neutrino masses, corresponding to an effective mass parameter |m_{ee}| >= 0.17 \\sqrt{\\Delta m^2_{ATM}}. This result holds both for the CP conserving and CP violating cases. In the latter case we show explicitly that the lower bound on |m_{ee}| is sensitive to the value of the Majorana phase. We conclude therefore that in our scheme, neutrinoless double beta decay may be accessible to the next generation of high sensitivity experiments.

  5. Time evolution of cascade decay

    E-Print Network [OSTI]

    Daniel Boyanovsky; Louis Lello

    2014-06-25T23:59:59.000Z

    We study non-perturbatively the time evolution of cascade decay for generic fields $\\pi \\rightarrow \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$ and obtain the time dependence of amplitudes and populations for the resonant and final states. We analyze in detail the different time scales and the manifestation of unitary time evolution in the dynamics of production and decay of resonant intermediate and final states. The probability of occupation (population) "flows" as a function of time from the initial to the final states. When the decay width of the parent particle $\\Gamma_\\pi$ is much larger than that of the intermediate resonant state $\\Gamma_{\\phi_1}$ there is a "bottleneck" in the flow, the population of resonant states builds up to a maximum at $t^* = \\ln[\\Gamma_\\pi/\\Gamma_{\\phi_1}]/(\\Gamma_\\pi-\\Gamma_{\\phi_1})$ nearly saturating unitarity and decays to the final state on the longer time scale $1/\\Gamma_{\\phi_1}$. As a consequence of the wide separation of time scales in this case the cascade decay can be interpreted as evolving sequentially $\\pi \\rightarrow \\phi_1\\phi_2; ~ \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$. In the opposite limit the population of resonances ($\\phi_1$) does not build up substantially and the cascade decay proceeds almost directly from the initial parent to the final state without resulting in a large amplitude of the resonant state. An alternative but equivalent non-perturbative method useful in cosmology is presented. Possible phenomenological implications for heavy sterile neutrinos as resonant states and consequences of quantum entanglement and correlations in the final state are discussed.

  6. Background discrimination in neutrinoless double beta decay search with $\\textrm{TeO}_{2}$ bolometers using Neganov-Luke amplified cryogenic light detectors

    E-Print Network [OSTI]

    Willers, M; Giuliani, A; Gütlein, A; Münster, A; Lanfranchi, J -C; Oberauer, L; Potzel, W; Roth, S; Schönert, S; Sivers, M v; Wawoczny, S; Zöller, A

    2014-01-01T23:59:59.000Z

    We demonstrate that Neganov-Luke amplified cryogenic light detectors with Transition Edge Sensor read-out can be applied for the background suppression in cryogenic experiments searching for the neutrinoless double beta decay of $^{130}\\text{Te}$ with $\\text{TeO}_{2}$ based bolometers. Electron and gamma induced events can be discriminated from $\\alpha$ events by detecting the Cherenkov light produced by the $\\beta$ particles emitted in the decay. We use the Cherenkov light produced by events in the full energy peak of $^{208}\\text{Tl}$ and by events from a $^{147}\\text{Sm}$ source to show that at the Q-value of the neutrinoless double beta decay of $^{130}\\text{Te}$ ($Q_{\\beta \\beta} = 2.53 \\,\\text{MeV}$), a separation of $e^{-}/\\gamma$ events from $\\alpha$ events can be achieved on an event-by-event basis with practically no reduction in signal acceptance.

  7. Neganov-Luke amplified cryogenic light detectors for the background discrimination in neutrinoless double beta decay search with TeO$_{2}$ bolometers

    E-Print Network [OSTI]

    M. Willers; F. v. Feilitzsch; A. Giuliani; A. Gütlein; A. Münster; J. -C. Lanfranchi; L. Oberauer; W. Potzel; S. Roth; S. Schönert; M. v. Sivers; S. Wawoczny; A. Zöller

    2014-11-28T23:59:59.000Z

    We demonstrate that Neganov-Luke amplified cryogenic light detectors with Transition Edge Sensor read-out can be applied for the background suppression in cryogenic experiments searching for the neutrinoless double beta decay of $^{130}\\text{Te}$ with TeO$_{2}$ based bolometers. Electron and gamma induced events can be discriminated from $\\alpha$ events by detecting the Cherenkov light produced by the $\\beta$ particles emitted in the decay. We use the Cherenkov light produced by events in the full energy peak of $^{208}\\text{Tl}$ and by events from a $^{147}\\text{Sm}$ source to show that at the Q-value of the neutrinoless double beta decay of $^{130}\\text{Te}$ ($Q_{\\beta \\beta} = 2.53 \\,\\text{MeV}$), a separation of $e^{-}/\\gamma$ events from $\\alpha$ events can be achieved on an event-by-event basis with practically no reduction in signal acceptance.

  8. What can we learn from neutrinoless double beta decay experiments?

    E-Print Network [OSTI]

    Bahcall, John N.

    2009-01-01T23:59:59.000Z

    Limits From Neutrinoless Double-Beta Decay (Rev. ),” ina next generation neutrinoless double beta decay search andPARTICLES? NO NEUTRINOLESS DOUBLE BETA DECAY AND INVERTED

  9. INFRARED OBSERVATIONS OF THE MILLISECOND PULSAR BINARY J1023+0038: EVIDENCE FOR THE SHORT-TERM NATURE OF ITS INTERACTING PHASE IN 2000-2001

    SciTech Connect (OSTI)

    Wang, Xuebing; Wang, Zhongxiang [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)] [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Morrell, Nidia [Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena (Chile)] [Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena (Chile)

    2013-02-20T23:59:59.000Z

    We report our multi-band infrared (IR) imaging of the transitional millisecond pulsar system J1023+0038, a rare pulsar binary known to have an accretion disk in 2000-2001. The observations were carried out with ground-based and space telescopes from near-IR to far-IR wavelengths. We detected the source in near-IR JH bands and Spitzer 3.6 and 4.5 {mu}m mid-IR channels. Combined with the previously reported optical spectrum of the source, the IR emission is found to arise from the companion star, with no excess emission detected in the wavelength range. Because our near-IR fluxes are nearly equal to those obtained by the 2MASS all-sky survey in 2000 February, the result indicates that the binary did not contain the accretion disk at the time, whose existence would have raised the near-IR fluxes to twice larger values. Our observations have thus established the short-term nature of the interacting phase seen in 2000-2001: the accretion disk existed for at most 2.5 yr. The binary was not detected by the WISE all-sky survey carried out in 2010 at its 12 and 22 {mu}m bands and our Herschel far-IR imaging at 70 and 160 {mu}m. Depending on the assumed properties of the dust, the resulting flux upper limits provide a constraint of <3 Multiplication-Sign 10{sup 22}-3 Multiplication-Sign 10{sup 25} g on the mass of the dust grains that possibly exist as the remnants of the previously seen accretion disk.

  10. Angular analysis of polarized top quark decay into B-mesons in two different helicity systems

    E-Print Network [OSTI]

    S. Mohammad Moosavi Nejad; Mahboobe Balali

    2014-10-16T23:59:59.000Z

    We calculate the ${\\cal O}(\\alpha_s)$ radiative corrections to the spin dependent differential decay rates of the process $t\\rightarrow b+W^+$. These are needed to study the angular distribution of the energy of hadrons produced in polarized top quark decays at next-to-leading order (NLO). In our previous work, we studied the angular distribution of the scaled-energy of bottom-flavored hadrons (B) from polarized top quark decays, using a specific helicity coordinate system where the top quark spin was measured relative to the bottom momentum (system~1). Here, we study the angular distribution of the energy spectrum of B-hadron in a different helicity system, where the top spin is specified relative to the W-momentum (system~2). These energy distributions are governed by the polarized and unpolarized rate functions which are related to the density matrix elements of the decay $t\\rightarrow W^++b$. Through this paper, we present our predictions of the B-hadron spectrum in the polarized and unpolarized top decay and shall compare the polarized results in two different helicity systems. These predictions can be used to determine the polarization states of top quarks and also provide direct access to the B-hadron fragmentation functions (FFs) and allow us to deepen our knowledge of the hadroniazation process.

  11. Constraining Majorana CP Phase in Precision Era of Cosmology and Double Beta Decay Experiment

    E-Print Network [OSTI]

    Hisakazu Minakata; Hiroshi Nunokawa; Alexander A. Quiroga

    2015-03-02T23:59:59.000Z

    We show that precision measurement of (1) sum of neutrino masses by cosmological observation and (2) lifetime of neutrinoless double beta decay in ton-scale experiments, with supplementary use of (3) effective mass measured in single beta decay experiment, would allow us to obtain information on the Majorana phase of neutrinos. To quantify the sensitivity to the phase we use the CP exclusion fraction, a fraction of the CP phase parameter space that can be excluded for a given set of assumed input parameters, a global measure for CP violation. We illustrate the sensitivity under varying assumptions, from modest to optimistic ones, on experimental errors and theoretical uncertainty of nuclear matrix elements. Assuming that the latter can be reduced to a factor of ~1.5 we find that one of the two Majorana phases (denoted as alpha_(21)) can be constrained by excluding ~10-40% of the phase space at 2sigma CL even with the modest choice of experimental error for the lowest neutrino mass of 0.1 eV. The characteristic features of the sensitivity to alpha_(21), such as dependences on the true values of alpha_(21), are addressed.

  12. The acoustic spectrum of alpha Cen A

    E-Print Network [OSTI]

    F. Bouchy; F. Carrier

    2002-06-04T23:59:59.000Z

    This paper presents the analysis of Doppler p-mode observations of the G2V star $\\alpha$ Cen A obtained with the spectrograph CORALIE in May 2001. Thirteen nights of observations have made it possible to collect 1850 radial velocity measurements with a standard deviation of about 1.5 m s$^{-1}$. Twenty-eight oscillation modes have been identified in the power spectrum between 1.8 and 2.9 mHz with amplitudes in the range 12 to 44 cm s$^{-1}$. The average large and small spacing are respectively equal to 105.5 and 5.6 $\\mu$Hz. A comparison with stellar models of $\\alpha$ Cen A is presented.

  13. $\\alpha$ Centauri A in the far infrared

    E-Print Network [OSTI]

    Liseau, R; Olofsson, G; Bryden, G; Marshall, J P; Ardila, D; Aran, A Bayo; Danchi, W C; del Burgo, C; Eiroa, C; Ertel, S; Fridlund, M C W; Krivov, A V; Pilbratt, G L; Roberge, A; Thébault, P; Wiegert, J; White, G J

    2012-01-01T23:59:59.000Z

    Chromospheres and coronae are common phenomena on solar-type stars. Understanding the energy transfer to these heated atmospheric layers requires direct access to the relevant empirical data. Study of these structures has, by and large, been limited to the Sun thus far. The region of the temperature reversal can be directly observed only in the far infrared and submm. We aim at the determination of the characteristics of the atmosphere in the region of the temperature minimum of the solar sister star alpha Cen A. For the nearby binary system alpha Centauri, stellar parameters are known with high accuracy from measurements. For the basic model parameters Teff, log g and [Fe/H], we interpolate in the grid of GAIA/PHOENIX stellar model atmospheres and compute the corresponding model for the G2 V star alpha Cen A. Comparison with photometric measurements shows excellent agreement between observed photospheric data in the optical and infrared. For longer wavelengths, the modelled spectral energy distribution is co...

  14. Lyman-alpha Absorption from Heliosheath Neutrals

    E-Print Network [OSTI]

    Brian E. Wood; Vladislav V. Izmodenov; Jeffrey L. Linsky; Yury G. Malama

    2006-11-30T23:59:59.000Z

    We assess what information HST observations of stellar Ly-alpha lines can provide on the heliosheath, the region of the heliosphere between the termination shock and heliopause. To search for evidence of heliosheath absorption, we conduct a systematic inspection of stellar Ly-alpha lines reconstructed after correcting for ISM absorption (and heliospheric/astrospheric absorption, if present). Most of the stellar lines are well centered on the stellar radial velocity, as expected, but the three lines of sight with the most downwind orientations relative to the ISM flow (Chi1 Ori, HD 28205, and HD 28568) have significantly blueshifted Ly-alpha lines. Since it is in downwind directions where heliosheath absorption should be strongest, the blueshifts are almost certainly caused by previously undetected heliosheath absorption. We make an initial comparison between the heliosheath absorption and the predictions of a pair of heliospheric models. A model with a complex multi-component treatment of plasma within the heliosphere predicts less absorption than a model with a simple single-fluid treatment, which leads to better agreement with the data. Finally, we find that nonplanetary energetic neutral atom (ENA) fluxes measured by the ASPERA-3 instrument on board Mars Express, which have been interpreted as being from the heliosheath, are probably too high to be consistent with the relative lack of heliosheath absorption seen by HST. This would argue for a local interplanetary source for these ENAs instead of a heliosheath source.

  15. Alpha Particle Physics Experiments in the Tokamak Fusion Test Reactor

    SciTech Connect (OSTI)

    Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Zweben, S.J.; et al.

    1998-12-14T23:59:59.000Z

    Alpha particle physics experiments were done on the Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium (DT) run from 1993-1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single-particle confinement model in magnetohydrodynamic (MHD) quiescent discharges. Also, the observed alpha particle interactions with sawteeth, toroidal Alfvén eigenmodes (TAE), and ion cyclotron resonant frequency (ICRF) waves were roughly consistent with theoretical modeling. This paper reviews what was learned and identifies what remains to be understood.

  16. Detection of alpha radiation in a beta radiation field

    DOE Patents [OSTI]

    Mohagheghi, Amir H. (Albuquerque, NM); Reese, Robert P. (Edgewood, NM)

    2001-01-01T23:59:59.000Z

    An apparatus and method for detecting alpha particles in the presence of high activities of beta particles utilizing an alpha spectrometer. The apparatus of the present invention utilizes a magnetic field applied around the sample in an alpha spectrometer to deflect the beta particles from the sample prior to reaching the detector, thus permitting detection of low concentrations of alpha particles. In the method of the invention, the strength of magnetic field required to adequately deflect the beta particles and permit alpha particle detection is given by an algorithm that controls the field strength as a function of sample beta energy and the distance of the sample to the detector.

  17. Variations of decay rates of radio-active elements and their connections with global anisotropy of physical space

    E-Print Network [OSTI]

    Yu. A. Baurov; I. F. Malov

    2010-01-29T23:59:59.000Z

    The analysis of correlations between fluctuations of alpha- and beta-decay rates for different radio-active elements is carried out. These fluctuations exceed significantly errors of measurements in many cases. They have the periodical character and reveal definite spatial directions. We suggest that the observed fluctuations are caused by the unique physical reason connected with the global anisotropy of physical space and by the new force.

  18. Non-statistical decay and -correlations in the1 C fusion-evaporation reaction at 95 MeV2

    E-Print Network [OSTI]

    Boyer, Edmond

    NUCLEAR REACTIONS 12C(12C,X), E = 95 AMeV, Measured Fusion-evaporation32 reactions, Observed deviationNon-statistical decay and -correlations in the1 12 C+12 C fusion-evaporation reaction at 95 MeV2 L. Multiple alpha coincidences and correlations are studied in the reaction21 12 C+12 C at 95 MeV for fusion

  19. Decay constants of heavy-light vector mesons from QCD sum rules

    E-Print Network [OSTI]

    Patrick Gelhausen; Alexander Khodjamirian; Alexei A. Pivovarov; Denis Rosenthal

    2015-03-27T23:59:59.000Z

    We revisit QCD sum rules for the decay constants of heavy-light mesons. In the sum rules for the vector mesons B^*_(s) and D^*_(s) we improve the accuracy of OPE, taking into account the O(alpha_s^2) terms in the perturbative part and calculating the O(alpha_s) corrections to the quark-condensate contribution. With this accuracy, we obtain the ratios of decay constants: f_B^*/f_B=1.02 +0.07 -0.03, f_D^*/f_D=1.20 +0.10 -0.07. The sum rule predictions for the decay constants of pseudoscalar mesons are updated with the results f_B=(207 +17 -9) MeV, f_B_s=(242 +17 -12) MeV, f_D=(201 +12 -13) MeV, f_D_s=(238 +13 -23) MeV. In order to assess the sensitivity of our calculation to the form of the sum rule, we consider alternative versions such as the power moments and Borel sum rules with different weights of the spectral density. We also investigated the heavy quark limit of the sum rules for vector and pseudoscalar mesons, estimating the violations of the heavy-quark spin and flavour symmetry.

  20. Beta decay of Ga-62 

    E-Print Network [OSTI]

    Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.

    2003-01-01T23:59:59.000Z

    We report a study of the beta decay of Ga-62, whose dominant branch is a superallowed 0(+)-->0(+) transition to the ground state of Zn-62. We find the total half-life to be 115.84+/-0.25 ms. This is the first time that the Ga-62 half-life has been...

  1. Constraining neutrinoless double beta decay

    E-Print Network [OSTI]

    L. Dorame; D. Meloni; S. Morisi; E. Peinado; J. W. F. Valle

    2011-11-23T23:59:59.000Z

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  2. Beta decay of Ga-62

    E-Print Network [OSTI]

    Hyman, BC; Iacob, VE; Azhari, A.; Gagliardi, Carl A.; Hardy, John C.; Mayes, VE; Neilson, RG; Sanchez-Vega, M.; Tang, X.; Trache, L.; Tribble, Robert E.

    2003-01-01T23:59:59.000Z

    from the ex- perimental ft value for a 01?01 b decay between analog states with the relation @3# 0556-2813/2003/68~1!/015501~6!/$20.00 68 015501- of 62Ga . Hardy, V. E. Mayes, R. G. Neilson, M. Sanchez-Vega, and R. E. Tribble y, College Station...

  3. Rare decays at the Tevatron

    SciTech Connect (OSTI)

    Farrington, S.M.; /Liverpool U.

    2006-01-01T23:59:59.000Z

    The confidence level limits of the CDF and D0 searches for the B{sub s}{sup 0}, B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} rare decays are presented.

  4. Proton decay matrix elements from lattice QCD 

    E-Print Network [OSTI]

    Cooney, Paul

    2010-01-01T23:59:59.000Z

    We present results for the matrix elements relevant for proton decay in Grand Unified Theories (GUTs), using two methods. In the indirect method, we rely on an effective field theory description of proton decay, where ...

  5. Radiative Penguin Decays at the B Factories

    SciTech Connect (OSTI)

    Cuhadar-Donszelmann, T.; /British Columbia U.

    2007-03-05T23:59:59.000Z

    Recent results from the B-Factories on radiative decays such as b {yields} s(d){gamma}, b {yields} s{ell}{ell} and leptonic decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} are reviewed.

  6. New Physics from NSIs in charm Decays

    E-Print Network [OSTI]

    Shakeel Mahmood; Farida Tahir; Azeem Mir

    2014-11-04T23:59:59.000Z

    We study rare decays of Charm in NSIs. We calculate the NSIs Branching ratios of these decays. There is a strong dependence of these on new physics parameter. They provide, stringent constraints on free parameter in tau.

  7. A compilation of information on the {sup 31}P(p,{alpha}){sup 28}Si reaction and properties of excited levels in the compound nucleus {sup 32}S

    SciTech Connect (OSTI)

    Miller, R.E.; Smith, D.L. [Argonne National Lab., IL (United States). Technology Development Div.] [Argonne National Lab., IL (United States). Technology Development Div.

    1997-11-01T23:59:59.000Z

    This report documents a survey of the literature, and provides a compilation of data contained therein, for the {sup 31}P(p,{alpha}){sup 28}Si reaction. Attention is paid here to resonance states in the compound-nuclear system {sup 32}S formed by {sup 31}P + p, with emphasis on the alpha-particle decay channels, {sup 28}Si + {alpha} which populate specific levels in {sup 28}Si. The energy region near the proton separation energy for {sup 32}S is especially important in this context for applications in nuclear astrophysics. Properties of the excited states in {sup 28}Si are also considered. Summaries of all the located references are provided and numerical data contained in them are compiled in EXFOR format where applicable.

  8. Determination of $\\alpha_{s}$ using Jet Rates at LEP with the OPAL detector

    E-Print Network [OSTI]

    Abbiendi, G; Åkesson, P F; Alexander, G; Anagnostou, G; Anderson, K J; Asai, S; Axen, D; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, F L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, R J; Herten, G; Heuer, R D; Hill, J C; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, D; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krasznahorkay, A; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Lafferty, G D; Landsman, H; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Mashimo, T; Mättig, P; McKenna, J A; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2006-01-01T23:59:59.000Z

    Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy range by fitting an expression in which order alpah_2s calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of alpha_s (Mz) was determined to be alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032

  9. Performance of ZnMoO4 crystal as cryogenic scintillating bolometer to search for double beta decay of molybdenum

    E-Print Network [OSTI]

    L. Gironi; C. Arnaboldi; J. W. Beeman; O. Cremonesi; F. A. Danevich; V. Ya. Degoda; L. I. Ivleva; L. L. Nagornaya; M. Pavan; G. Pessina; S. Pirro; V. I. Tretyak; I. A. Tupitsyna

    2010-10-01T23:59:59.000Z

    Zinc molybdate (ZnMoO4) single crystals were grown for the first time by the Czochralski method and their luminescence was measured under X ray excitation in the temperature range 85-400 K. Properties of ZnMoO4 crystal as cryogenic low temperature scintillator were checked for the first time. Radioactive contamination of the ZnMoO4 crystal was estimated as <0.3 mBq/kg (228-Th) and 8 mBq/kg (226-Ra). Thanks to the simultaneous measurement of the scintillation light and the phonon signal, the alpha particles can be discriminated from the gamma/beta interactions, making this compound extremely promising for the search of neutrinoless Double Beta Decay of 100-Mo. We also report on the ability to discriminate the alpha-induced background without the light measurement, thanks to a different shape of the thermal signal that characterizes gamma/beta and alpha particle interactions.

  10. Imperfect World of $??$-decay Nuclear Data Sets?

    E-Print Network [OSTI]

    B. Pritychenko

    2015-03-11T23:59:59.000Z

    The precision of double-beta ($\\beta\\beta$) decay experimental half-lives and their uncertainties is reevaluated. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of $\\beta\\beta$-decay half-lives and nuclear matrix elements.

  11. Imperfect World of $??$-decay Nuclear Data Sets

    E-Print Network [OSTI]

    B. Pritychenko

    2015-01-09T23:59:59.000Z

    The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\

  12. Light-Quark Decays in Heavy Hadrons

    E-Print Network [OSTI]

    Faller, Sven

    2015-01-01T23:59:59.000Z

    We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. Theses decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays are interesting as a QCD laboratory to study the behaviour of the light quarks in the colour-background field of the heavy spectator.

  13. Double beta decay: experiments and theory review

    E-Print Network [OSTI]

    A. Nucciotti

    2007-07-28T23:59:59.000Z

    Neutrinoless double beta decay is one of the most powerful tools to set the neutrino mass absolute scale and establish whether the neutrino is a Majorana particle. After a summary of the neutrinoless double beta decay phenomenology, the present status of the experimental search for this rare decay is reported and the prospects for next generation experiments are reviewed.

  14. Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

    SciTech Connect (OSTI)

    Escher, J E; Dietrich, F S

    2008-05-23T23:59:59.000Z

    In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

  15. Particle decay branching ratios for states of astrophysical importance in 19Ne

    E-Print Network [OSTI]

    D. W. Visser; J. A. Caggiano; R. Lewis; W. B. Handler; A. Parikh; P. D. Parker

    2004-02-26T23:59:59.000Z

    We have measured proton and alpha-particle branching ratios of excited states in 19Ne formed using the 19F(3He,t) reaction at a beam energy of 25 MeV. These ratios have a large impact on the astrophysical reaction rates of 15O(alpha,gamma), 18F(p,gamma) and 18F(p,alpha), which are of interest in understanding energy generation in x-ray bursts and in interpreting anticipated gamma-ray observations of novae. We detect decay protons and alpha-particles using a silicon detector array in coincidence with tritons measured in the focal plane detector of our Enge split-pole spectrograph. The silicon array consists of five strip detectors of the type used in the Louvain-Edinburgh Detector Array, subtending angles from 130 degrees to 165 degrees with approximately 14% lab efficiency. The correlation angular distributions give additional confidence in some prior spin-parity assignments that were based on gamma branchings. We measure Gamma_p/Gamma=0.387+-0.016 for the 665 keV proton resonance, which agrees well with the direct measurement of Bardayan et al.

  16. Penguin pollution in the B^0 -> J/psi K_S decay

    E-Print Network [OSTI]

    Hsiang-nan Li; Satoshi Mishima

    2007-03-02T23:59:59.000Z

    We present the most complete analysis of the penguin correction to the extraction of the standard-model parameter sin(2\\phi_1) from the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \\alpha_s, \\phi_1 being the weak phase, m_b the b quark mass, and \\alpha_s the strong coupling constant. The deviation \\Delta S_{J/psi K_S} of the mixing-induced CP asymmetry from sin(2\\phi_1) and the direct CP asymmetry A_{J/psi K_S} are both found to be of O(10^{-3}) in a formalism that combines the QCD-improved factorization and perturbative QCD approaches. The above results, different from those of O(10^{-4}) and of O(10^{-2}) obtained in the previous calculations, provide an important standard-model reference for verifying new physics from the B^0 -> J/psi K_S data.

  17. Dalitz plot studies in hadronic charm decays

    E-Print Network [OSTI]

    Leonard Lesniak

    2014-11-06T23:59:59.000Z

    Recent studies of hadronic -meson decays are reported. Some experimental searches of CP-symmetry violation using model independent methods are presented. An importance of unitarity constraints in construction of phenomenological models of the D-meson decays is underlined. The theoretical model of the D0 --> K0S pi+ pi- decays, including some two-body unitarity constraints, is described. Then a comparison of the model results with the Belle collaboration data is made. The results on the CP-violation in the D0 --> K0S pi+ pi- decays are given and the necessity to consider the CP-violation in the subsequent K0S decays is emphasized.

  18. Neutralino dark matter from heavy axino decay

    SciTech Connect (OSTI)

    Choi, Ki-Young [Departamento de Fisica Teorica C-XI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Kim, Jihn E. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Lee, Hyun Min [Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Seto, Osamu [Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2008-06-15T23:59:59.000Z

    We consider cosmological consequences of a heavy axino, decaying to the neutralino in R-parity conserving models. The importance and influence of the axino decay on the resultant abundance of neutralino dark matter depends on the lifetime and the energy density of axino. For a high reheating temperature after inflation, copiously produced axinos dominate the energy density of the universe, and its decay produces a large amount of entropy. As a bonus, we obtain that the upper bound on the reheating temperature after inflation via gravitino decay can be moderated, because the entropy production by the axino decay more or less dilutes the gravitinos.

  19. International decay data evaluation project

    SciTech Connect (OSTI)

    Helmer, R.G.

    1996-10-01T23:59:59.000Z

    Basic concepts of, and information from, radionuclide decay are used in many applications. The author limits this discussion to the data needed for applied {gamma}-ray spectrometry; this includes applications such as nuclide identification and quantitative assay. Many of these applications require a knowledge of half-lives and radiation energies and emission probabilities. For over 50 years, people have compiled and evaluated measured data with the goal of obtaining the best values of these quantities. This has resulted in numerous sets of recommended values, many of which still have scientific, historical, or national reasons for existing. These sets show varying degrees of agreement and disagreement in the quoted values and varying time lags in incorporating new and improved experimental results. A new informational international group has been formed to carry out evaluations for radionuclides of importance in applications; it is expected that the results will become an authoritative and widely accepted set of decay data.

  20. $\\tau$ decays with neutral kaons

    E-Print Network [OSTI]

    Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anderson, K J; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Bailey, I; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Davis, R; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Rembser, C; Rick, Hartmut; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

    2000-01-01T23:59:59.000Z

    The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0 resonance. The measurement is based on two samples which identify one-prong tau decays with KL and KS mesons. The combined branching ratios are measured to be B(tau- -->pi- K0bar nutau) = (9.33+-0.68+-0.49)x10^-3 B(tau- -->pi- K0bar [>=1pi0] nutau) = (3.24+-0.74+-0.66)x10^-3 B(tau- -->K- K0bar [>=0pi0] nutau) = (3.30+-0.55+-0.39)x10^-3 where the first error is statistical and the second systematic.

  1. Alpha resonant scattering for astrophysical reaction studies

    SciTech Connect (OSTI)

    Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study (CNS), University of Tokyo, RIKEN campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y.; Kubano, S. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayakawa, S. [Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95125 Catania (Italy); Kawabata, T. [Department of Physics, Kyoto University, Kita-Shirakawa, Kyoto 606-8502 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-811 (Korea, Republic of); Binh, D. N. [30 MeV Cyclotron Center, Tran Hung Dao Hospital, Hoan Kiem District, Hanoi (Viet Nam); Khiem, L. H.; Duy, N. G. [Institute of Physics, Vietnam Academy of Science and Technology, 18 Hong Quoc Viet, Nghia do, Hanoi (Viet Nam)

    2014-05-02T23:59:59.000Z

    Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the ? resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+? resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(?,?) reaction, and proposed a new cluster band in {sup 11}C.

  2. Alpha Renewable Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat Place: Wayne,Energy Information Jump to:Alpha Energy Place:

  3. Tri Alpha Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin Hydropower StationTown ofTownNote-BangladeshTri Alpha Energy

  4. Nuclear Half-Lives for Alpha Radioactivity of Elements with 100 $\\leq$ Z $\\leq$ 130

    E-Print Network [OSTI]

    P. Roy Chowdhury; C. Samanta; D. N. Basu

    2008-02-29T23:59:59.000Z

    Theoretical estimates for the half lives of about 1700 isotopes of heavy elements with Z from 100 to 130 are tabulated using theoretical Q-values. The quantum mechanical tunneling probabilities are calculated within a WKB framework using microscopic nuclear potentials. The microscopic nucleus-nucleus potentials are obtained by folding the densities of interacting nuclei with a density dependent M3Y (DDM3Y) effective nucleon-nucleon interaction. The alpha-decay half lives calculated in this formalism using the experimental Q-values were found to be in good agreement over a wide range of experimental data spanning about twenty orders of magnitude. The theoretical Q-values used for the present calculations are extracted from three different mass estimates viz. Myers-Swiatecki [MS], Muntian-Hofmann-Patyk-Sobiczewski [M] and Koura-Tachibana-Uno-Yamada [KUTY].

  5. Speeding-up Thorium decay

    E-Print Network [OSTI]

    F. Cardone; R. Mignani; A. Petrucci

    2007-10-26T23:59:59.000Z

    We show that cavitation of a solution of thorium-228 in water induces its transformation at a rate 10000 times faster than the natural radioactive decay would do. This result agrees with the alteration of the secular equilibrium of thorium-234 obtained by a Russian team via explosion of titanium foils in water and solutions. These evidences further support some preliminary clues for the possibility of piezonuclear reactions (namely nuclear reactions induced by pressure waves) obtained in the last ten years.

  6. Autoresonant soliton and decay pumping

    E-Print Network [OSTI]

    O. M. Kiselev

    2013-01-29T23:59:59.000Z

    The primary resonance equation in partial derivatives with external force and slowly varying frequency is derived. The leading-order term of asymptotic solution is constructed as a soliton with growing amplitude when time is large. This growing solution is obtained due to the decaying amplitude of the external force. A necessary condition for the growth of the solution in dissipative media is obtained also.

  7. Cosmic recycling of millisecond pulsars

    E-Print Network [OSTI]

    Wynn C. G. Ho; Thomas J. Maccarone; Nils Andersson

    2011-04-07T23:59:59.000Z

    We compare the rotation rate of neutron stars in low-mass X-ray binaries (LMXBs) with the orbital period of the binaries. We find that, while short orbital period LMXBs span a range of neutron star rotation rates, all the long period LMXBs have fast rotators. We also find that the rotation rates are highest for the systems with the highest mean mass accretion rates, as can be expected if the accretion rate correlates with the orbital period. We show that these properties can be understood by a balance between spin-up due to accretion and spin-down due to gravitational radiation. Our scenario indicates that the gravitational radiation emitted by these systems may be detectable by future ground-based gravitational wave detectors.

  8. H$\\alpha$ and EUV observations of a partial CME

    E-Print Network [OSTI]

    Christian, Damian J; Antolin, Patrick; Mathioudakis, Mihalis

    2015-01-01T23:59:59.000Z

    We have obtained H$\\alpha$ high spatial and time resolution observations of the upper solar chromosphere and supplemented these with multi-wavelength observations from the Solar Dynamic Observatory (SDO) and the {\\it Hinode} ExtremeUltraviolet Imaging Spectrometer (EIS). The H$\\alpha$ observations were conducted on 11 February 2012 with the Hydrogen-Alpha Rapid Dynamics Camera (HARDcam) instrument at the National Solar Observatory's Dunn Solar Telescope. Our H$\\alpha$ observations found large downflows of chromospheric material returning from coronal heights following a failed prominence eruption. We have detected several large condensations ("blobs") returning to the solar surface at velocities of $\\approx$200 km s$^{-1}$ in both H$\\alpha$ and several SDO AIA band passes. The average derived size of these "blobs" in H$\\alpha$ is 500 by 3000 km$^2$ in the directions perpendicular and parallel to the direction of travel, respectively. A comparison of our "blob" widths to those found from coronal rain, indicate...

  9. Lyman alpha Absorption Systems and the Intergalactic Medium

    E-Print Network [OSTI]

    George Efstathiou; Joop Schaye; Tom Theuns

    2000-04-10T23:59:59.000Z

    The last few years have seen a dramatic improvement in our understanding of the origin of Lyman alpha absorption systems. Hydrodynamic numerical simulations of cold dark matter dominated universes have shown that the many properties of the Lyman alpha absorption systems can be explained by a photoionized, space-filling, intergalactic medium. Lyman alpha lines offer promising probes of the photoionizing background, the amplitude of the mass fluctuations at high redshift and the evolution of the equation of state of the intergalactic medium.

  10. alpha 1-adrenoceptor antagonist: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 5 Antagonistic competition moderates virulence in Bacillus thuringiensis...

  11. alpha spectrometry measurement: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  12. alpha spectrometry 232u: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the source. Simulations and measurements highlight the importance of coincidences in high-resolution alpha spectrometry. To show the validity of the simulated results,...

  13. alpha coding sequence: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  14. alpha spectrometry contribution: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  15. alpha spectrometry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  16. alpha spectrometry system: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  17. alpha spectrometry caracterizacao: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Carlo code, known as AASI, is developed for simulating energy spectra in alpha spectrometry. The code documented here is a comprehensive package where all the major processes...

  18. alpha spectrometers: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Flight CERN Preprints Summary: The Alpha Magnetic Spectrometer (AMS) is a particle detector designed to detect antimatter. During the 10-day test flight on the space shuttle in...

  19. Penguin pollution estimates relevant for phi_2/alpha extraction

    E-Print Network [OSTI]

    Jure Zupan

    2007-08-16T23:59:59.000Z

    A review of methods to extract the standard CKM unitarity triangle angle alpha is provided. The sizes of related theoretical errors are reviewed.

  20. alpha receptor interactions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    derived from the Wigner transform of the nonlocal Lambda alpha kernel shows a strong energy dependence for the incident Lambda-particle, indicating the importance of the...

  1. alpha 1-adrenergic receptor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    implicated in lipid homeostasis-Activated Receptor alpha (PPAR ) is a key regulator of energy homeostasis ( ) and 1 -5 the anti-inflammatory response homeostasis, through its9...

  2. acid receptor alpha: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    implicated in lipid homeostasis-Activated Receptor alpha (PPAR ) is a key regulator of energy homeostasis ( ) and 1 -5 the anti-inflammatory response homeostasis, through its9...

  3. alpha radiation influencia: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    plant species. Search method: In nature, most alpha radiation exposure is caused by radon progeny. Exposure is particularly high below ground, and is also elevated on plant...

  4. alpha particle irradiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  5. alpha particles irradiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  6. alpha radiation detection: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    plant species. Search method: In nature, most alpha radiation exposure is caused by radon progeny. Exposure is particularly high below ground, and is also elevated on plant...

  7. alpha-particle emitting radiopharmaceuticals: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    44 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  8. alpha particle response: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    62 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  9. alpha particle detector: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    K.N. 2 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  10. alpha detector lrad: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    7 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  11. alpha particle irradiated: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  12. apres irradiation alpha: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Edmond 8 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  13. alpha radiation measuring: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    plant species. Search method: In nature, most alpha radiation exposure is caused by radon progeny. Exposure is particularly high below ground, and is also elevated on plant...

  14. alpha rays: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    observation of GRB 991216, may provide important constraints on the immediate environment of the burst and hence on progenitor models. The large Fe K-alpha equivalent widths...

  15. New features in the stability and fission decay of superheavy Thorium isotopes

    E-Print Network [OSTI]

    L. Satpathy; S. K. Patra; R. K. Choudhury

    2006-04-12T23:59:59.000Z

    Superheavy isotopes are highly neutron rich nuclei in the vicinity of neutron drip-line, stabilized by shell effect against the instability due to repulsive component of nuclear force, analogous to superheavy elements similarly stabilized against Coulomb instability. Here we discuss the stability and fission decay properties of such nuclei in the $^{254}$Th region and show that they are stable against $\\alpha$ and fission decay and have $\\beta$-decay life time of several tens of seconds. In particular, the $^{254}$Th nucleus has a low fission barrier and unusally large barrier width. This makes it an ideal thermally fissile nucleus, if formed by means of a thermal neutron, like other known nuclei such as $^{233}$U, $^{235}$U, $^{239}$Pu in this actinide region. It shows a new mode of fast fission decay, which may be termed as multifragmentation fission, in which in addition to two heavy fragments large number of scission neutrons are simultaneously produced. Its likely synthesis during the r-process nucleosynthesis will have important bearing on steller evolution, and here in the laboratory, it has great potential in energy production.

  16. CP asymmetry in $B^- to pi^+ pi^- K^-$ and $B^- to K^+ K^- K^-$ decays

    E-Print Network [OSTI]

    Pham, T N

    2003-01-01T23:59:59.000Z

    The near equality between the measured value for $|V_{ub}|/|V_{cb}|$ and its unitarity triangle lower bound from $sin 2beta$ measurements suggests that $alpha approx 90^{circ}$ and $singamma approx cosbeta = 0.91$ and a large direct CP violation in B decays would be possible. In this talk, I would like to discuss a recent analysis of the non resonant and resonant CP asymmetry for the decays $B^- to pi^+ pi^- K^-$ and $B^- to K^+ K^- K^-$ where the CP asymmetry at the $chi_{c0}$ resonance comes from the interference of the non resonant amplitude with the resonant amplitude $B^pm to chi_{c0} K^pm $ $ topi^+ pi^- K^pm $ and $B^pm to chi_{c0} K^pm$ $ to K^+ K^- K^pm$. Using the the Babar and Belle measurements of the $B^-to chi_{c0} K^- $ branching ratios, we predict that partial width asymmetry at the $chi_{c0}$ resonance could reach 10% for the $B^- to pi^+ pi^- K^-$ decay and 16% for the $B^- to K^+ K^- K^-$decay.

  17. Origin of the Structures in the C-12(o-16,alpha) Reaction - Dominance of Ne-20-Star and O-16-Star Sequential Alpha-Decay Processes

    E-Print Network [OSTI]

    Murakami, T.; Ungricht, E.; Takahashi, N.; Lui, YW; Mihara, Y.; Neese, R. E.; Takada, E.; Tanner, D. M.; Tribble, Robert E.; Nagatani, K.

    1984-01-01T23:59:59.000Z

    ?(24Mg)=20.2 MeV state. The solid and dashed curves are the theoretical spectra obtatined by the Hauser-Feshbach code EVA (see the text, Sec. V). I oo 0.5- 0.0 50 I I30 20 E?( Mg} MeV l39.4 I36.4 l33.5 IO B. Experimental results Inclusive..., we modified the Monte Carlo code EVA (Ref. 23) which fol- lows the Hauser-Feshbach formalism. The calculation in- cludes the successive evaporation of neutrons, protons, and a particles. The level densities used are from the prescription...

  18. Dark Decay of the Top Quark

    SciTech Connect (OSTI)

    Kong, Kyoungchul; Lee, Hye-Sung; Park, Myeonghun

    2014-04-01T23:59:59.000Z

    We suggest top quark decays as a venue to search for light dark force carriers. The top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6sigma deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t-->bW+Z's. This is the same as the dominant top quark decay (t-->bW) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. We discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.

  19. Electroweak penguin decays at LHCb

    E-Print Network [OSTI]

    Thomas Blake

    2011-09-29T23:59:59.000Z

    Promising ways to search for New Physics effects in radiative penguin decays are in the angular analysis of $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$, in the measurement of direct CP violation in $\\B_{d} \\rightarrow K^{*0}\\mu^{+}\\mu^{-}$ and a time dependent analysis of $B_{s} \\rightarrow \\phi \\gamma$. All of these studies are being pursued at LHCb. First results will be shown from the 2010 and early 2011 data, with particular emphasis on $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$.

  20. Neutrinoless double beta decay experiments

    E-Print Network [OSTI]

    K. Zuber

    2006-10-04T23:59:59.000Z

    The study of neutrinoless double beta decay is of outmost importance for neutrino physics. It is considered to be the gold plated channel to probe the fundamental character of neutrinos and to determine the neutrino mass. From the experimental point about nine different isotopes are explored for the search. After a general introduction follows a short discussion on nuclear matrix element calculations and supportive measurements. The current experimental status of double beta searches is presented followed by a short discussion of the ideas and proposals for large scale experiments.

  1. Experimental study of rare charged pion decays

    E-Print Network [OSTI]

    Dinko Pocanic; Emil Frlez; Andries van der Schaaf

    2014-07-10T23:59:59.000Z

    The combination of simple dynamics, small number of available decay channels, and extremely well controlled radiative and loop corrections, make charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for improving our understanding of pion structure and chiral dynamics. This paper reviews the current state of experimental study of the allowed rare decays of charged pions: (a) leptonic, $\\pi^+ \\to e^+\

  2. Neutrinoless Double Beta Decay and CP Violation

    E-Print Network [OSTI]

    Patrick J. O'Donnell; Utpal Sarkar

    1993-05-27T23:59:59.000Z

    We study the relation between the Majorana neutrino mass matrices and the neutrinoless double beta decay when CP is not conserved. We give an explicit form of the decay rate in terms of a rephasing invariant quantity and demonstrate that in the presence of CP violation it is impossible to have vanishing neutrinoless double beta decay in the case of two neutrino generations (or when the third generation leptons do not mix with other leptons and hence decouple).

  3. Dental Decay Among Texas School Children.

    E-Print Network [OSTI]

    Whitacre, Jessie (Jessie Opal)

    1934-01-01T23:59:59.000Z

    more often found ama older than the younger ones. With all children the numb( ing decayed 6-year molars increased rapidly with age up or 14 years. lightly more girls than boys in each race had decayed tee 'he data secured in this study suggest a... to Caries i vith Other Recent Studies I AcknowIedgm Summary Literature Ci ents -_---. ted -------- CTIN NO. 491 AUGUST, 1934 DENTAL DECAY AMONG TEXAS SCHOOL CHILDREN* sometix extensi Seve: aualifif agcum someti] diet (6 to curl...

  4. Lyman Alpha Absorption in The Cosmic Web

    E-Print Network [OSTI]

    J. Richard Bond; James W. Wadsley

    1997-10-10T23:59:59.000Z

    We describe large scale structure at high redshift in terms of the Cosmic Web picture for {S,Lambda,O,H}CDM models: how galactic-scale ``peak-patches'', filaments and membranes create an interconnected intergalactic medium. The ideas are applied to our Ly$\\alpha$ forest simulations of ``shear-field patches''. We discuss simulation method and design, resolution dependence, the statistical combination of patches, UV flux scaling, and whether filtered Zel'dovich maps are useful. The response to changes in power spectrum shape and amplitude, and in cosmological parameters, is described. We also show Omega_b h^2 derived from UV rescaling is overestimated if the resolution is not adequate.

  5. Constraining |V(td)|/|V(ts)| Using Radiative Penguin B -> V(K*/rho/omega)gamma Decays

    SciTech Connect (OSTI)

    Tan, Ping; /Wisconsin U., Madison

    2006-03-08T23:59:59.000Z

    Exclusive radiative penguin B decays, B {yields} (K*{sup 0}/K*{sup +}) and B {yields} ({rho}/{omega}){gamma}, are flavor-changing neutral-current (FCNC) processes. Studies of these decays are of special interest in testing Standard Model (SM) predictions and searching for other beyond-the-SM FCNC interactions. Using 89 x 10{sup 6} B{bar B} pairs from BABAR, we measure the branching fraction ({Beta}), CP-asymmetry ({Alpha}), and isospin asymmetry ({Delta}{sub 0-}) of B {yields} (K*{sup 0}/K*{sup +}){gamma} as follows: {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = 3.92 {+-} 0.20(stat.) {+-} 0.24(syst.); {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = 3.87 {+-} 0.28(stat.) {+-} 0.26(syst.); {Alpha}(B {yields} K*{gamma}) = -0.013 {+-} 0.36(stat.) {+-} 0.10(syst.); {Delta}{sub 0-}(B {yields} K*{gamma}) = 0.050 {+-} 0.045(stat.) {+-} 0.028(syst.) {+-} 0.024(R{sup +/0}). The 90% confidence intervals for the CP-asymmetry and the isospin-asymmetry in the B {yields} K*{gamma} decay are given as: -0.074 < {Alpha}(B {yields} K*{gamma}) < 0.049, -0.046 < {Delta}{sub 0-} (B {yields} K*{gamma}) < 0.146. We also search for B {yields} ({rho}/{omega}){gamma} decays using 211 x 10{sup 6} B{bar B} pairs from BABAR. No evidence for these decays is found. We set the upper limits at 90% confidence level for these decays: {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 0.4 x 10{sup -6}; {Beta}(B{sup +}{yields} {rho}{sup =}{gamma}) < 1.8 x 10{sup -6}; {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6}; {bar {Beta}}(B {yields} ({rho}/{omega}){gamma}) < 1.2 x 10{sup -6}. These results are in good agreement with the SM predictions. The branching fractions of these decays are then used to constrain the ratio |V{sub td}|/|V{sub ts}|.

  6. The Decay of the Neutron or Beta Decay, the Big Bang, and the...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Decay of the Neutron or Beta Decay, the Big Bang, and the Left-Handed Universe Apr 03 2014 01:00 PM - 02:30 PM Geoffrey L. Greene Physics Division, ORNL Research Accelerator...

  7. Spectroscopy of element 115 decay chains

    SciTech Connect (OSTI)

    Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

    2013-01-01T23:59:59.000Z

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  8. Nuclear beta-decay measurements and |Vud|

    E-Print Network [OSTI]

    Dan Melconian

    2011-08-11T23:59:59.000Z

    Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.

  9. Displacement Echoes: Classical Decay and Quantum Freeze

    E-Print Network [OSTI]

    Cyril Petitjean; Diego V. Bevilaqua; Eric J. Heller; Philippe Jacquod

    2007-04-23T23:59:59.000Z

    Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.

  10. Review of double beta decay experiments

    E-Print Network [OSTI]

    A. S. Barabash

    2014-03-12T23:59:59.000Z

    The brief review of current experiments on search and studying of double beta decay processes is done. Best present limits on $\\langle m_{\

  11. Operator Analysis of Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Kiwoon Choi; Kwang Sik Jeong; Wan Young Song

    2002-07-19T23:59:59.000Z

    We study the effective operators of the standard model fields which would yield an observable rate of neutrinoless double beta decay. We particularly focus on the possibility that neutrinoless double beta decay is dominantly induced by lepton-number-violating higher dimensional operators other than the Majorana neutrino mass. Our analysis can be applied to models in which neutrinoless double beta decay is induced either by a strong dynamics or by quantum gravity effects at a fundamental scale near the TeV scale as well as the conventional models in which neutrinoless double beta decay is induced by perturbative renormalizable interactions.

  12. New limits for neutrinoless tau decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.

    1998-05-01T23:59:59.000Z

    double beta decays, neutrino oscillations, Z!l11l22 decays, and other rare pro- cesses. In particular, there are strict limits on muon neutrino- less decays: B(m!eg),4.9310211 and B(m!eee),2.4 310212 at 90% confidence level @18#. However, lepton num- ber... particles and on the new coupling constants. The most optimistic branching fraction predictions are at the level of about 1026. Constraints on lepton flavor violation come from studies of rare and forbidden K , p, and m decays, e-m conversions, neutrinoless...

  13. Neutrinoless Double Beta Decay and Neutrino Masses

    E-Print Network [OSTI]

    Michael Duerr

    2012-06-04T23:59:59.000Z

    Neutrinoless double beta decay is a promising test for lepton number violating physics beyond the standard model of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between neutrinoless double beta decay and Majorana neutrino masses provided by the so-called Schechter--Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate neutrinoless double beta decay from unknown nuclear background using only one isotope, i.e., within one experiment.

  14. Neutrinoless Double Beta Decay: Present and Future

    E-Print Network [OSTI]

    Oliviero Cremonesi

    2002-10-04T23:59:59.000Z

    Present status, and future plans for Double Beta Decay searches are reviewed. Given the recent observations of neutrino oscillations, a possibility to observe $\\beta\\beta(0\

  15. Displacement Echoes: Classical Decay and Quantum Freeze

    SciTech Connect (OSTI)

    Petitjean, Cyril [Departement de Physique Theorique, Universite de Geneve, CH-1211 Geneva 4 (Switzerland); Bevilaqua, Diego V. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Heller, Eric J. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Jacquod, Philippe [Physics Department, University of Arizona, Tucson, Arizona 85721 (United States)

    2007-04-20T23:59:59.000Z

    Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase-space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations.

  16. Triply Differential Jet Cross Sections for Hadron Collisions at Order alpha_s^3 in QCD

    E-Print Network [OSTI]

    Stephen D. Ellis; Davison E. Soper

    1994-12-22T23:59:59.000Z

    We discuss cross sections for hadron + hadron to 2 jets + anything in which three jet variables are measured. Such cross sections are useful especially for determining parton distributions. We define a new cross section d sigma/dX_A dX_B d eta_* for which the perturbation theory is nicely behaved even in the kinematic regime where the parton distributions are probed at large momentum fractions. The cross section d\\sigma/dE_{T1}\\, d\\eta_1\\, d\\eta_2, which has been used in the past, is not so well behaved in this region. We calculate these cross sections at order $\\alpha_s^3$ in QCD.

  17. On the Experimental Identification of Spin-Parities and Single-Particle Configurations in $^{257}$No and Its $?$-Decay Daughter $^{253}$Fm

    E-Print Network [OSTI]

    P. Roy Chowdhury; D. N. Basu

    2005-12-30T23:59:59.000Z

    Recently measured lifetimes of the favored $\\alpha$ decays from $^{257}$No have been calculated using the quantum mechanical tunneling within WKB approximation using microscopic nuclear potentials. Results obtained assuming previously assigned (ambiguous) parent spin of $\\frac{7^+}{2}$ and newly assigned configuration $\\frac{3^+}{2}$ [622] have been compared. Hindrance factors for the favored decays have also been compared with the calculated hindrances using higher angular momenta transfers. Although the calculations substantiate the findings, yet it makes the spin-parity assignment of $\\frac{3^+}{2}$ for the ground state of $^{257}$No less definite.

  18. Measurements of CP-Violating Asymmetries and Branching Fractions in the Decays of B Mesons to Charged Pions and Kaons at the Babar Detector

    SciTech Connect (OSTI)

    Danielson, Morris Nicholas; /Princeton U.

    2006-04-10T23:59:59.000Z

    This dissertation describes the measurement of branching fractions and CP asymmetries in neutral B meson decays to charmless two-body final states of charged pions and kaons. CP violation is a poorly-constrained phenomenon in the Standard model (SM) of particle physics and had been studied only in the kaon system before the Babar and Belle experiments. The decay of the neutral B meson to charged pions and kaons is particularly useful for the study of CP violation because they can be related to the Unitarity Triangle angle {alpha}.

  19. alpha 7l test: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    alpha 7l test First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Remote associates test and alpha brain...

  20. Measurements of the angle alpha (phi2) at B factories

    E-Print Network [OSTI]

    G. Vasseur

    2008-10-02T23:59:59.000Z

    The measurements of the angle alpha (phi2) of the unitarity triangle at the B factories are reviewed. The value of alpha determined by combining the results obtained in the B to pi pi, B to rho pi, and B to rho rho modes by both the BABAR and Belle experiments is (87.5 +6.2 -5.3) degrees.

  1. Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies

    E-Print Network [OSTI]

    P. Mohr; G. G. Kiss; Zs. Fülöp; D. Galaviz; Gy. Gyürky; E. Somorjai

    2012-12-12T23:59:59.000Z

    High precision angular distribution data of ($\\alpha$,$\\alpha$) elastic scattering are presented for the nuclei $^{89}$Y, $^{92}$Mo, $^{106,110,116}$Cd, $^{112,124}$Sn, and $^{144}$Sm at energies around the Coulomb barrier. Such data with small experimental uncertainties over the full angular range (20-170 degrees) are the indispensable prerequisite for the extraction of local optical potentials and for the determination of the total reaction cross section $\\sigma_{\\rm{reac}}$. A systematic fitting procedure was applied to the presented experimental scattering data to obtain comprehensive local potential parameter sets which are composed of a real folding potential and an imaginary potential of Woods-Saxon surface type. The obtained potential parameters were used in turn to construct a new systematic $\\alpha$-nucleus potential with very few parameters. Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.

  2. A simple procedure to prepare spherical {alpha}-alumina powders

    SciTech Connect (OSTI)

    Liu Hongyu [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China); Ning Guiling [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China)], E-mail: ninggl@dlut.edu.cn; Gan Zhihong; Lin Yuan [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China)

    2009-04-02T23:59:59.000Z

    Spherical {alpha}-alumina powders were prepared by the controlled hydrolysis of aluminum isopropoxide in a hydrolysis system consisting of octanol and acetonitrile. Diverse solvents to dissolve reactant formed diverse hydrolysis systems and affected particle shape of {alpha}-alumina powders. The precursors crystallized to {gamma}-alumina at 1000 deg. C and converted to {alpha}-alumina at 1150 deg. C without intermediate phases. The particle morphology of precursor was retained after it crystallized to {alpha}-alumina. The heating rate influenced the particle shape and the state of agglomeration during calcination process. The thermal properties of the precursors were characterized by thermal gravimetric and differential thermal analysis. X-ray diffraction technique was used to confirm the conversion of crystalline phase of alumina powders from amorphous to {alpha}-phase. Transmission electron microscopy was used to investigate the morphologies and size of the precursors and products.

  3. Exclusive Radiative Higgs Decays as Probes of Light-Quark Yukawa Couplings

    E-Print Network [OSTI]

    Koenig, Matthias

    2015-01-01T23:59:59.000Z

    We present a detailed analysis of the rare exclusive Higgs-boson decays into a single vector meson and a photon and investigate the possibility of using these processes to probe the light-quark Yukawa couplings. We work with an effective Lagrangian with modified Higgs couplings to account for possible new-physics effects in a model-independent way. The h->V\\gamma{} decay rate is governed by the destructive interference of two amplitudes, one of which involves the Higgs coupling to the quark anti-quark pair inside the vector meson. We derive this amplitude at next-to-leading order in \\alpha_s using QCD factorization, including the resummation of large logarithmic corrections and accounting for the effects of flavor mixing. The high factorization scale \\mu~m_h ensures that our results are rather insensitive to poorly known hadronic parameters. The second amplitude arises from the loop-induced effective h\\gamma\\gamma* and h\\gamma Z* couplings, where the off-shell gauge boson converts into the vector meson. We de...

  4. alpha tnfa-induced pre-b: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 5 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  5. alpha 2u-globulin hyaline: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 ALPHA OMEGA ALPHA National Honor Medical Society Biology and Medicine...

  6. Thalamocortical Mechanisms for the Anteriorization of Alpha Rhythms during Propofol-Induced Unconsciousness

    E-Print Network [OSTI]

    Vijayan, Sujith

    As humans are induced into a state of general anesthesia via propofol, the normal alpha rhythm (8–13 Hz) in the occipital cortex disappears and a frontal alpha rhythm emerges. This spatial shift in alpha activity is called ...

  7. Neutrino oscillations and neutrinoless double beta decay

    E-Print Network [OSTI]

    D. Falcone; F. Tramontano

    2001-03-16T23:59:59.000Z

    The relation between neutrino oscillation parameters and neutrinoless double beta decay is studied, assuming normal and inverse hierarchies for Majorana neutrino masses. For normal hierarchy the crucial dependence on U_{e3} is explored. The link with tritium beta decay is also briefly discussed.

  8. Neutrinoless double beta decay and neutrino physics

    E-Print Network [OSTI]

    Werner Rodejohann

    2012-08-20T23:59:59.000Z

    The connection of neutrino physics with neutrinoless double beta decay is reviewed. After presenting the current status of the PMNS matrix and the theoretical background of neutrino mass and lepton mixing, we will summarize the various implications of neutrino physics for double beta decay. The influence of light sterile neutrinos and other exotic modifications of the three neutrino picture is also discussed.

  9. Spectroscopy and decays of charm and bottom

    SciTech Connect (OSTI)

    Butler, J.N.

    1997-10-01T23:59:59.000Z

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.

  10. alpha-particle radiobiological experiments: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We...

  11. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    In 2010 the ALPHA collaboration succeeded in trapping antihydrogen atoms for the first time.[i]  Stored antihydrogen promises to be a unique tool for making high precision measurements of the structure of this first anti-atom. Achieving this milestone presented several substantial experimental challenges and this talk will describe how they were overcome.   The unique design features of the ALPHA apparatus will be explained.[ii]  These allow a high intensity positron source and an antiproton imaging detector similar to the one used in the ATHENA[iii] experiment to be combined with an innovative magnet design of the anti-atom trap. This seeks to minimise the perturbations to trapped charged particles which may cause particle loss and heating[iv].   The diagnostic techniques used to measure the diameter, number, density, and temperatures of both plasmas will be presented as will the methods developed to actively compress and cool of both plasma species to sizes and temperatures [v],[vi], [vii] where trapping attempts with a reasonable chance of success can be tried.   The results of the successful trapping experiments will be outlined as well as some subsequent experiments to improve the trapping rate and storage time. [i] 'Trapped antihydrogen' G.B. Andresen et al., Nature 468, 673 (2010) [ii]'A Magnetic Trap for Antihydrogen Confinement' W. Bertsche et al., Nucl. Instr. Meth. Phys. Res. A566, 746 (2006) [iii] Production and detection of cold antihydrogen atoms M.Amoretti et al., Nature 419, 456 (2002). [iv]' Antihydrogen formation dynamics in a multipolar neutral anti-atom trap' G.B. Andresen et al., Phys. Lett. B 685, 141 (2010) [v]' Evaporative Cooling of Antiprotons to Cryogenic Temperatures',                                   G.B. Andresen et al. Phys. Rev. Lett 105, 013003 (2010) [vi]'Compression of Antiproton Clouds for Antihydrogen Trapping' G. B. Andresen et al. Phys. Rev. Lett 100, 203401 (2008) [vii]  'Autoresonant Excitation of Antiproton Plasmas' G.B. Andresen et al., Phys. Rev. Lett. 106, 025002 (2011) Organizer: Ferdinand Hahn PH/DT Detector Seminar webpage  

  12. Strong effects in weak nonleptonic decays

    SciTech Connect (OSTI)

    Wise, M.B.

    1980-04-01T23:59:59.000Z

    In this report the weak nonleptonic decays of kaons and hyperons are examined with the hope of gaining insight into a recently proposed mechanism for the ..delta..I = 1/2 rule. The effective Hamiltonian for ..delta..S = 1 weak nonleptonic decays and that for K/sup 0/-anti K/sup 0/ mixing are calculated in the six-quark model using the leading logarithmic approximation. These are used to examine the CP violation parameters of the kaon system. It is found that if Penguin-type diagrams make important contributions to K ..-->.. ..pi pi.. decay amplitudes then upcoming experiments may be able to distinguish the six-quark model for CP violation from the superweak model. The weak radiative decays of hyperons are discussed with an emphasis on what they can teach us about hyperon nonleptonic decays and the ..delta..I = 1/2 rule.

  13. Neutrinoless Double Beta Decay in Light of SNO Salt Data

    E-Print Network [OSTI]

    Murayama, Hitoshi

    2009-01-01T23:59:59.000Z

    Limits From Neutrinoless Double-Beta Decay (Rev. ),” incan also cause neutrinoless double-beta decay (see e.g. , [LBNL-53996 Neutrinoless Double Beta Decay in Light of SNO

  14. A Search for Neutrinoless Double Beta Decay of Te-130

    E-Print Network [OSTI]

    Bryant, Adam Douglas

    2010-01-01T23:59:59.000Z

    A Search for Neutrinoless Double Beta Decay of Te by AdamA Search for Neutrinoless Double Beta Decay of CopyrightA Search for Neutrinoless Double Beta Decay of Te by Adam

  15. Predicting neutrinoless double beta decay

    SciTech Connect (OSTI)

    Hirsch, M.; Villanova del Moral, A.; Valle, J.W.F. [AHEP Group, Instituto de Fisica Corpuscular - C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain); Ma, Ernest [Physics Department, University of California, Riverside, California 92521 (United States); Institute for Particle Physics Phenomenology, University of Durham, Durham, DH1 3LE (United Kingdom)

    2005-11-01T23:59:59.000Z

    We give predictions for the neutrinoless double beta decay rate in a simple variant of the A{sub 4} family symmetry model. We show that there is a lower bound for the {beta}{beta}{sub 0{nu}} amplitude even in the case of normal hierarchical neutrino masses, corresponding to an effective mass parameter vertical bar m{sub ee} vertical bar {>=}0.17{radical}({delta}m{sub ATM}{sup 2}). This result holds both for the CP conserving and CP violating cases. In the latter case we show explicitly that the lower bound on vertical bar m{sub ee} vertical bar is sensitive to the value of the Majorana phase. We conclude therefore that in our scheme, {beta}{beta}{sub 0{nu}} may be accessible to the next generation of high sensitivity experiments.

  16. IGFBP-3, hypoxia and TNF-{alpha} inhibit adiponectin transcription

    SciTech Connect (OSTI)

    Zappala, Giovanna, E-mail: zappalag@mail.nih.gov [Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States)] [Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States); Rechler, Matthew M. [Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States) [Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States); Clinical Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States)

    2009-05-15T23:59:59.000Z

    The thiazolidinedione rosiglitazone, an agonist ligand for the nuclear receptor PPAR-{gamma}, improves insulin sensitivity in part by stimulating transcription of the insulin-sensitizing adipokine adiponectin. It activates PPAR-{gamma}-RXR-{alpha} heterodimers bound to PPAR-{gamma} response elements in the adiponectin promoter. Rosiglitazone-stimulated adiponectin protein synthesis in 3T3-L1 mouse adipocytes has been shown to be inhibited by IGFBP-3, which can be induced by hypoxia and the proinflammatory cytokine, TNF-{alpha}, two inhibitors of adiponectin transcription. The present study demonstrates that IGFBP-3, the hypoxia-mimetic agent cobalt chloride, and TNF-{alpha} inhibit rosiglitazone-induced adiponectin transcription in mouse embryo fibroblasts that stably express PPAR-{gamma}2. Native IGFBP-3 can bind RXR-{alpha} and inhibited rosiglitazone stimulated promoter activity, whereas an IGFBP-3 mutant that does not bind RXR-{alpha} did not. These results suggest that IGFBP-3 may mediate the inhibition of adiponectin transcription by hypoxia and TNF-{alpha}, and that IGFBP-3 binding to RXR-{alpha} may be required for the observed inhibition.

  17. H{alpha} ABSORPTION IN TRANSITING EXOPLANET ATMOSPHERES

    SciTech Connect (OSTI)

    Christie, Duncan; Arras, Phil; Li Zhiyun, E-mail: dac5zm@virginia.edu, E-mail: pla7y@virginia.edu, E-mail: zl4h@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2013-08-01T23:59:59.000Z

    Absorption of stellar H{alpha} by the upper atmosphere of the planet HD 189733b has recently been detected by Jensen et al. Motivated by this observation, we have developed a model for atomic hydrogen in the n = 2 state and compared the resulting H{alpha} line profile to the observations. The model atmosphere is in hydrostatic balance, as well as thermal and photoionization equilibrium. Collisional and radiative transitions are included in the determination of the n = 2 state level population. We find that H{alpha} absorption is dominated by an optical depth {tau} {approx} 1 shell, composed of hydrogen in the metastable 2s state that is located below the hydrogen ionization layer. The number density of the 2s state within the shell is found to vary slowly with radius, while that of the 1s state falls rapidly. Thus while the Ly{alpha} absorption, for a certain wavelength, occurs inside a relatively well defined impact parameter, the contribution to H{alpha} absorption is roughly uniform over the entire atomic hydrogen layer. The model can approximately reproduce the observed Ly{alpha} and H{alpha} integrated transit depths for HD 189733b by using an ionization rate enhanced over that expected for the star by an order of magnitude. For HD 209458b, we are unable to explain the asymmetric H{alpha} line profile observed by Jensen et al., as the model produces a symmetric line profile with transit depth comparable to that of HD 189733b. In an appendix, we study the effect of the stellar Ly{alpha} absorption on the net cooling rate.

  18. Selective flow path alpha particle detector and method of use

    DOE Patents [OSTI]

    Orr, Christopher Henry (Sellafield, Seascale, Cumbria, GB); Luff, Craig Janson (Sellafield, Seascale, Cumbria, GB); Dockray, Thomas (Sellafield, Seascale, Cumbria, GB); Macarthur, Duncan Whittemore (P.O. Box 1663, Los Alamos, NM 87545)

    2002-01-01T23:59:59.000Z

    A method and apparatus for monitoring alpha contamination are provided in which ions generated in the air surrounding the item, by the passage of alpha particles, are moved to a distant detector location. The parts of the item from which ions are withdrawn can be controlled by restricting the air flow over different portions of the apparatus. In this way, detection of internal and external surfaces separately, for instance, can be provided. The apparatus and method are particularly suited for use in undertaking alpha contamination measurements during the commissioning operations.

  19. Non-resonant triple alpha reaction rate at low temperature

    SciTech Connect (OSTI)

    Itoh, T.; Tamii, A.; Aoi, N.; Fujita, H.; Hashimoto, T.; Miki, K.; Ogata, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Carter, J.; Donaldson, L.; Sideras-Haddad, E. [Schools of Physics, University of Witwatersrand, Johannesburg 2050 (South Africa); Furuno, T.; Kawabata, T. [Departments of Physics, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Kamimura, M. [RIKEN Nishina Center, Wako, Saitama, 351-0198 (Japan); Nemulodi, F.; Neveling, R.; Smit, F. D.; Swarts, C. [iThemba Laboratory for Accelerator Based Sciences Somerset, West, 7129 (South Africa)

    2014-05-02T23:59:59.000Z

    Our experimental goal is to study the non-resonant triple alpha reaction rate at low temperture (T < 10{sup 8} K). The {sup 13}C(p,d) reaction at 66 MeV has been used to probe the alpha-unbound continuum state in {sup 12}C just below the 2{sup nd} 0{sup +} state at 7.65 MeV. The transition strength to the continuum state is predicted to be sensitive to the non-resonant triple alpha reaction rate. The experiment has been performed at iThemba LABS. We report the present status of the experiment.

  20. Particle Physics Aspects of Antihydrogen Studies with ALPHA at CERN

    E-Print Network [OSTI]

    ALPHA Collaboration; M. C. Fujiwara; G. B. Andresen; W. Bertsche; P. D. Bowe; C. C. Bray; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; J. Fajans; R. Funakoshi; D. R. Gill; J. S. Hangst; W. N. Hardy; R. S. Hayano; M. E. Hayden; A. J. Humphries; R. Hydomako; M. J. Jenkins; L. V. Jorgensen; L. Kurchaninov; W. Lai; R. Lambo; N. Madsen; P. Nolan; K. Olchanski; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; S. Seif El Nasr; D. M. Silveira; J. W. Storey; R. I. Thompson; D. P. van der Werf; L. Wasilenko; J. S. Wurtele; Y. Yamazaki

    2008-05-27T23:59:59.000Z

    We discuss aspects of antihydrogen studies, that relate to particle physics ideas and techniques, within the context of the ALPHA experiment at CERN's Antiproton Decelerator facility. We review the fundamental physics motivations for antihydrogen studies, and their potential physics reach. We argue that initial spectroscopy measurements, once antihydrogen is trapped, could provide competitive tests of CPT, possibly probing physics at the Planck Scale. We discuss some of the particle detection techniques used in ALPHA. Preliminary results from commissioning studies of a partial system of the ALPHA Si vertex detector are presented, the results of which highlight the power of annihilation vertex detection capability in antihydrogen studies.

  1. Single and double grid long-range alpha detectors

    DOE Patents [OSTI]

    MacArthur, Duncan W. (Los Alamos, NM); Allander, Krag S. (Ojo Caliente, NM)

    1993-01-01T23:59:59.000Z

    Alpha particle detectors capable of detecting alpha radiation from distant sources. In one embodiment, a voltage is generated in a single electrically conductive grid while a fan draws air containing air molecules ionized by alpha particles through an air passage and across the conductive grid. The current in the conductive grid can be detected and used for measurement or alarm. Another embodiment builds on this concept and provides an additional grid so that air ions of both polarities can be detected. The detector can be used in many applications, such as for pipe or duct, tank, or soil sample monitoring.

  2. Single and double grid long-range alpha detectors

    DOE Patents [OSTI]

    MacArthur, D.W.; Allander, K.S.

    1993-03-16T23:59:59.000Z

    Alpha particle detectors capable of detecting alpha radiation from distant sources. In one embodiment, a voltage is generated in a single electrically conductive grid while a fan draws air containing air molecules ionized by alpha particles through an air passage and across the conductive grid. The current in the conductive grid can be detected and used for measurement or alarm. Another embodiment builds on this concept and provides an additional grid so that air ions of both polarities can be detected. The detector can be used in many applications, such as for pipe or duct, tank, or soil sample monitoring.

  3. Mining for Metals in the Lyman Alpha Forest

    E-Print Network [OSTI]

    Sara L. Ellison; Antoinette Songaila; Joop Schaye; Max Pettini

    2000-02-14T23:59:59.000Z

    In order to ascertain the extent of metal enrichment in the Ly alpha forest, we have analysed a very high S/N spectrum of the z = 3.625 QSO Q1422+231. We find that in high column density Ly alpha clouds, the power law column density distribution function of C IV continues down to log N(C IV) = 11.7. In addition, by analysing pixel-by-pixel optical depths we show that there are considerably more metals in the Ly alpha forest than are currently directly detectable.

  4. auger decay spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2008-01-01 44 Constraining Mass Spectra with Sterile Neutrinos from Neutrinoless Double Beta Decay, Tritium Beta Decay and Cosmology HEP - Experiment (arXiv) Summary: We...

  5. Search for: "neutrinoless double beta decay" | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    neutrinoless double beta decay" Find + Advanced Search Advanced Search All Fields: "neutrinoless double beta decay" Title: Full Text: Bibliographic Data: Creator Author: Name...

  6. Proton decay matrix elements with domain-wall fermions

    E-Print Network [OSTI]

    Y. Aoki; C. Dawson; J. Noaki; A. Soni

    2006-09-18T23:59:59.000Z

    Hadronic matrix elements of operators relevant to nucleon decay in grand unified theories are calculated numerically using lattice QCD. In this context, the domain-wall fermion formulation, combined with non-perturbative renormalization, is used for the first time. These techniques bring reduction of a large fraction of the systematic error from the finite lattice spacing. Our main effort is devoted to a calculation performed in the quenched approximation, where the direct calculation of the nucleon to pseudoscalar matrix elements, as well as the indirect estimate of them from the nucleon to vacuum matrix elements, are performed. First results, using two flavors of dynamical domain-wall quarks for the nucleon to vacuum matrix elements are also presented to address the systematic error of quenching, which appears to be small compared to the other errors. Our results suggest that the representative value for the low energy constants from the nucleon to vacuum matrix elements are given as |alpha| simeq |beta| simeq 0.01 GeV^3. For a more reliable estimate of the physical low energy matrix elements, it is better to use the relevant form factors calculated in the direct method. The direct method tends to give smaller value of the form factors, compared to the indirect one, thus enhancing the proton life-time; indeed for the pi^0 final state the difference between the two methods is quite appreciable.

  7. Tribimaximal neutrino mixing and neutrinoless double beta decay

    SciTech Connect (OSTI)

    Hirsch, M.; Morisi, S.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular-- C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apt 22085, E-46071 Valencia (Spain)

    2008-11-01T23:59:59.000Z

    We present a tribimaximal lepton mixing scheme where the neutrinoless double beta decay rate has a lower bound which correlates with the ratio {alpha}{identical_to}{delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2} well determined by current data, as well as with the unknown Majorana CP phase {phi}{sub 12} characterizing the solar neutrino subsystem. For the special value {phi}{sub 12}=({pi}/2) (opposite CP-sign neutrinos) the {beta}{beta}{sub 0{nu}} rate vanishes at tree level when {delta}m{sub sol}{sup 2}/{delta}m{sub atm}{sup 2}=3/80, only allowed at 3{sigma}. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to {phi}{sub 12}=0. We suggest two model realizations of this scheme in terms of A{sub 4}xZ{sub 2} and A{sub 4}xZ{sub 4} flavor symmetries.

  8. Resonances in (11)C observed in the (4)He((7)Be, alpha)(7)Be and (4)He((7)Be, p)(10)B reactions

    SciTech Connect (OSTI)

    Freer, M. [University of Birmingham, The, Birmingham, United Kingdom; Ashwood, N. I. [University of Birmingham, The, Birmingham, United Kingdom; Curtis, N. [University of Birmingham, The, Birmingham, United Kingdom; Malcolm, J. [University of Birmingham, The, Birmingham, United Kingdom; Munoz-Britton, T. [University of Birmingham, The, Birmingham, United Kingdom; Price, D. [University of Birmingham, The, Birmingham, United Kingdom; Wheldon, C. [University of Birmingham, The, Birmingham, United Kingdom; Achouri, N. L. [CNRS/IN2P3, Caen, France; Laurent, B. [CNRS/IN2P3, Caen, France; Orr, N. A. [CNRS/IN2P3, Caen, France; Angulo, C. [Universite catholique de Louvain, Belgium (UCL); Demaret, P. [Universite Catholique de Louvain; Bardayan, Daniel W [ORNL; Pain, Steven D [ORNL; Brown, S. [University of Surrey, UK; Catford, W. [University of Surrey, UK; Harlin, Christopher W [ORNL; Thomas, J. S. [University of Surrey, England; Wilson, G. [University of Surrey, UK; Chipps, K. [Rutgers University; Milin, M. [Zagreb University, Zagreb, Croatia; Raabe, R. [Rudjer Boskovic Institute, Zagreb, Croatia; Soic, N. [Rudjer Boskovic Institute, Zagreb, Croatia

    2012-01-01T23:59:59.000Z

    Measurements of the {sup 4}He({sup 7}Be,{alpha}){sup 7}Be and {sup 4}He({sup 7}Be,p){sup 10}B reactions were performed using {sup 7}Be beam energies of 7.1 and 23 MeV and a helium-4 target, employing the thick target technique. Resonances were observed between E{sub x}({sup 11}C) = 8.6 to 13.8 MeV. An R-matrix analysis was performed to characterize the spins and partial widths. This analysis showed that the observed sequence of states was consistent with that found for {sup 7}Li + {alpha} resonant scattering populating resonances in {sup 11}B. A comparison of the proposed partial widths for decay with the Wigner limit indicates that several of the states are associated with cluster-like structures.

  9. The top quark to electron mass ratio m(t) = 18*m(e)/alpha^2 where alpha = e^2/hslash*c

    E-Print Network [OSTI]

    Malcolm H. Mac Gregor

    2006-03-24T23:59:59.000Z

    Threshold-state elementary particle lifetimes exhibit a scaling in powers of alpha = e^2/hslash*c, and a reciprocal electron-based 1/alpha scaling in particle masses that extends over two powers of 1/alpha. The m(e)/alpha coupling generates accurate q = (u,d), s, c, b quark masses for particles up to 11 GeV. The m(e)/alpha^2 coupling creates the "alpha-quarks" q^alpha = q/alpha that reproduce the top quark mass and average W^+-, Z^0 doublet mass. The calculated Bc mass is 6303.3 MeV/c^2, and the lattice QCD value is 6304 +- 12 MeV/c^2. The calculated and experimental top quark masses are m(t)calc = 18*m(e)/alpha^2 = 172.73 GeV/c^2 and m(t)exp = 172.5 +- 2.3 GeV/c^2.

  10. The formation and decay of superheavy nuclei produced in $^{48}Ca$-induced reactions

    E-Print Network [OSTI]

    Kumar, Sushil; Gupta, Raj K; Munzenberg, G; Scheid, W; 10.1088/0954-3899/29/4/303

    2011-01-01T23:59:59.000Z

    The formation of superheavy nuclei in $^{48}Ca+^{232}Th$, $^{238}U$, $^{242,244}Pu$ and $^{248}Cm$ reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT based preformed cluster-decay model (PCM) of Gupta and collaborators. According to QMFT, all these $^{48}Ca$-induced reactions are cold fusion reactions with relative excitation energies larger than for the $Pb$-induced cold fusion reactions and smaller than for the lighter beam i.e. $Mg$, $Si$ or $S$-induced hot fusion reactions. The same reactions were first suggested by Gupta et al. in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z=110 to 116, $^{50}Ca$ is shown to be a better beam for cold fusion, but $^{50}Ca$ is a radioactive nucleus. The $\\alpha$-decay half-lives of these nuclei after 3n and/ or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with experi...

  11. {alpha}-cluster states in N{ne}Z nuclei

    SciTech Connect (OSTI)

    Goldberg, V. Z.; Rogachev, G. V. [Cyclotron Institute, Texas A and M University, College Station, TX (United States); Department of Physics, Florida State University, Tallahassee, FL (United States) and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing (United States)

    2012-10-20T23:59:59.000Z

    The importance of studies of {alpha}-Cluster structure in N{ne}Z light nuclei is discussed. Spin-parity assignments for the low-lying levels in {sup 10}C are suggested.

  12. alpha methanotrophs provide: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 3 2002 Blackwell Science Ltd Estimation of methanotroph abundance in a...

  13. alpha fetoprotein radioimmunoassay: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 7 A SOLID-PHASE RADIOIMMUNOASSAY FOR THE DETERMINATION OF...

  14. alpha hydroxyprogesterone radioimmunoassay: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present review provides an update on alphas measurements from the past year. W. J. Stirling 1997-09-23 6 A SOLID-PHASE RADIOIMMUNOASSAY FOR THE DETERMINATION OF...

  15. alpha supports tumor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Romeel; Fardal, Mark A; Katz, Neal 2009-01-01 8 Lab 3 Answer Key. Analysis of gi|482321|pir||A41784 tumor necrosis factor-alpha-induced protein B12 human (the Biotechnology...

  16. atpase alpha model: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the...

  17. alpha interacting tip60: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the...

  18. alpha radioactivity measurement: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Evaluation of beta partical densitometry for determination of self-absorption factors in gross alpha and...

  19. alpha emitting radionuclides: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on the response function of a TeO2 bolometer to alpha's emitted by 147Sm dissolved in the crystal at the growth phase. A Quenching Factor of (1.0076pm...

  20. Linewidth enhancement factor. cap alpha. in semiconductor injection lasers

    SciTech Connect (OSTI)

    Vahala, K.; Chiu, L.C.; Margalit, S.; Yariv, A.

    1983-04-15T23:59:59.000Z

    A simple model for the linewidth enhancement factor ..cap alpha.. and its frequency dependence in semiconductor lasers is presented. Calculations based on this model are in reasonable agreement with experimental results.

  1. Energetics of [alpha]-helix formation in peptides and proteins

    E-Print Network [OSTI]

    Schubert, Christian Reinhold

    2009-01-01T23:59:59.000Z

    This thesis focuses on the energetics of !-helix formation in peptides and proteins. The [alpha]-helix is the most prevalent type of secondary structure found in proteins, and has arguably dominated our thinking about ...

  2. alpha 1-antitrypsin deficiency: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sparenberg, J M 2004-01-01 26 Dynamic Ly alpha jets Astrophysics (arXiv) Summary: The solar chromosphere and transition region are highly structured and complex regimes. A recent...

  3. alpha cell development: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    being catalyst. The range of fuels has further been extended to include ethanol and coal syn-gas by development 206 alphas and the tau hadronic width HEP - Phenomenology (arXiv)...

  4. Role of Hepatocyte Nuclear Factor 4 alpha in Hepatocyte Proliferation

    E-Print Network [OSTI]

    Walesky, Chad Michael

    2014-05-31T23:59:59.000Z

    Hepatocyte Nuclear Factor 4 alpha (HNF4?) is the master regulator of hepatocyte differentiation. It is involved in the up-regulation of genes involved in many classic hepatic functions including: bile acid metabolism, ...

  5. alpha beta gamma: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the decoupling limit, M2A0 gg M2Z, the heavy CP-even, CP-odd and charged Higgs boson masses are nearly degenerate, sin(beta-alpha) approaches 1, and the...

  6. alpha 1-noradrenergic receptors: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (more) Hayes, Brian Joseph 2014-01-01 2 Estrogen Receptor Alpha as a Key Target of Red Wine Polyphenols Action on the Endothelium Physics Websites Summary: -F, et al. (2010)...

  7. alpha receptor antagosist: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (more) Hayes, Brian Joseph 2014-01-01 2 Estrogen Receptor Alpha as a Key Target of Red Wine Polyphenols Action on the Endothelium Physics Websites Summary: -F, et al. (2010)...

  8. alpha spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Variations of alpha can be considered as one of the most reliable method to constrain the dark energy equation of state and improvements on the accuracy of the wavelength...

  9. alpha-proteobacterium sinorhizobium meliloti: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: Supplementary Fig. S1. Alignment of the last 36 amino acidic residues (HemP domain) of some HmuP homologues from the alpha, beta, gamma, delta and epsilon...

  10. B, D and K Decays

    SciTech Connect (OSTI)

    Artuso, M.; Asner, D.M.; Ball, P.; Baracchini, E.; Bell, G.; Beneke, M.; Berryhill, J.; Bevan, A.; Bigi, I.I.; Blanke, M.; Bobeth, Ch.; Bona, M.; Borzumati, F.; Browder, T.; Buanes, T.; Buchalla, G.; Buchmuller, O.; Buras, A.J.; Burdin, S.; Cassel, D.G.; Cavanaugh, R.; /Syracuse U. /Carleton U. /Durham U., IPPP /Rome U. /INFN, Rome /Karlsruhe U. /RWTH Aachen U. /Fermilab /Queen Mary, U. of London /Notre Dame U. /Munich, Tech. U. /Munich, Max Planck Inst. /Dortmund U. /Annecy, LAPP /ICTP, Trieste /Taiwan, Natl. Central U. /Hawaii U. /Bergen U. /Munich U. /CERN /Liverpool U.

    2008-03-07T23:59:59.000Z

    The present report documents the results of Working Group 2: B, D and K decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007. With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-p{sub T} and flavor data. This report is organized as follows. In Sec. 1, we give an overview of NP models, focusing on a few examples that have been discussed in some detail during the workshop, with a short description of the available computational tools for flavor observables in NP models. Sec. 2 contains a concise discussion of the main theoretical problem in flavor physics: the evaluation of the relevant hadronic matrix elements for weak decays. Sec. 3 contains a detailed discussion of NP effects in a set of flavor observables that we identified as 'benchmark channels' for NP searches. The experimental prospects for flavor physics at future facilities are discussed in Sec. 4. Finally, Sec. 5 contains some assessments on the work done at the workshop and the prospects for future developments.

  11. The strong decays of K1 resonances

    E-Print Network [OSTI]

    Andrey Tayduganov; Emi Kou; Alain Le Yaouanc

    2011-11-27T23:59:59.000Z

    We investigate the K1--> K pi pi strong interaction decays. Using the 3P0 quark-pair-creation model to derive the basic parametrization, we discuss in detail how to obtain the various partial wave amplitudes into the possible quasi-two-body decay channels as well as their relative phases from the currently available experimental data. We obtain the K1 mixing angle to be thetaK1= 60 deg, in agreement with previous works. Our study can be applied to extract the information needed for the photon polarization determination of the radiative B--> K1 gamma decay.

  12. Higgs boson decay to mu mubar gamma

    E-Print Network [OSTI]

    Ali Abbasabadi; Wayne W. Repko

    2000-04-17T23:59:59.000Z

    The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the tree level decay H -> mu mubar. We also show that the contributions to the radiative decay width from the interference terms between the tree and one-loop diagrams are negligible.

  13. beta-decay study of Cu-77

    E-Print Network [OSTI]

    N. Patronis; H. De Witte; M. Gorska; M. Huyse; K. Kruglov; D. Pauwels; K. Van de Vel; P. Van Duppen; J. Van Roosbroeck; J. -C. Thomas; S. Franchoo; J. Cederkall; V. N. Fedoseyev; H. Fynbo; U. Georg; O. Jonsson; U. Köster; T. Materna; L. Mathieu; O. Serot; L. Weissman; W. F. Mueller; V. I. Mishin; D. Fedorov

    2009-09-01T23:59:59.000Z

    A beta-decay study of Cu-77 has been performed at the ISOLDE mass separator with the aim to deduce its beta-decay properties and to obtain spectroscopic information on Zn-77. Neutron-rich copper isotopes were produced by means of proton- or neutron-induced fission reactions on U-238. After the production, Cu-77 was selectively laser ionized, mass separated and sent to different detection systems where beta-gamma and beta-n coincidence data were collected. We report on the deduced half-live, decay scheme, and possible spin assignment of 77Cu.

  14. Closed strings from decaying D-branes

    E-Print Network [OSTI]

    Neil Lambert; Hong Liu; Juan Maldacena

    2007-02-05T23:59:59.000Z

    We compute the emission of closed string radiation from homogeneous rolling tachyons. For an unstable decaying D$p$-brane the radiated energy is infinite to leading order for $p\\leq 2$ and finite for $p>2$. The closed string state produced by a decaying brane is closely related to the state produced by D-instantons at a critical Euclidean distance from $t=0$. In the case of a D0 brane one can cutoff this divergence so that we get a finite energy final state which would be the state that the brane decays into.

  15. Gauss-Bonnet Term on Vacuum Decay

    E-Print Network [OSTI]

    Rong-Gen Cai; Bin Hu; Seoktae Koh

    2008-11-20T23:59:59.000Z

    We study the effect of the Gauss-Bonnet term on vacuum decay process in the Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling with the real scalar field, which appears in the low energy effective action of string theories. We calculate numerically the instanton solution, which describes the process of vacuum decay, and obtain the critical size of bubble. We find that the Gauss-Bonnet term has a nontrivial effect on the false vacuum decay, depending on the Gauss-Bonnet coefficient.

  16. A comparative study of DNA polymerase alpha isolation

    E-Print Network [OSTI]

    Cernosek, Zina

    1987-01-01T23:59:59.000Z

    A COMPARATIVE STUDY OF DNA POLYMERASE ALPHA ISOLATION A Thesis by ZINA CERNOSEK Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1987 Major Subject...: Genetics A COMPARATIVE STUDY OF DNA POLYMERASE ALPHA ISOLATION A Thesis by ZINA CERNOSEK Approved as to style and content by: David L s ee (Chair of Committee) Jam E. Womack (Memb ) oren C. Skow (Member) Gerald R. Bratton (Head of Department...

  17. Labeled ALPHA4BETA2 ligands and methods therefor

    DOE Patents [OSTI]

    Mukherjee, Jogeshwar; Pichika, Ramaiah; Potkin, Steven; Leslie, Frances; Chattopadhyay, Sankha

    2013-02-19T23:59:59.000Z

    Contemplated compositions and methods are employed to bind in vitro and in vivo to an .alpha.4.beta.2 nicotinic acetylcholine receptor in a highly selective manner. Where such compounds are labeled, compositions and methods employing such compounds can be used for PET and SPECT analysis. Alternatively, and/or additionally contemplated compounds can be used as antagonists, partial agonists or agonists in the treatment of diseases or conditions associated with .alpha.4.beta..beta.2 dysfunction.

  18. Mapping the Cosmic Web with Ly-alpha Emission

    E-Print Network [OSTI]

    Steven Furlanetto; Joop Schaye; Volker Springel; Lars Hernquist

    2003-10-31T23:59:59.000Z

    We use a high-resolution cosmological simulation to predict the distribution of HI Ly-alpha emission from the low-redshift (z10^2 kpc) ``coronae'' of optically thin gas with Ly-alpha surface brightness close to the expected background. Most of these regions contain smaller cores of dense, cool gas. Unless self-shielded gas is able to cool to Tweb.

  19. Quantum Monte Carlo calculations of neutron-alpha scattering

    E-Print Network [OSTI]

    Kenneth M. Nollett; Steven C. Pieper; R. B. Wiringa; J. Carlson; G. M. Hale

    2006-12-09T23:59:59.000Z

    We describe a new method to treat low-energy scattering problems in few-nucleon systems, and we apply it to the five-body case of neutron-alpha scattering. The method allows precise calculations of low-lying resonances and their widths. We find that a good three-nucleon interaction is crucial to obtain an accurate description of neutron-alpha scattering.

  20. RAYLEIGH-TAYLOR STRENGTH EXPERIMENTS OF THE PRESSURE-INDUCED alpha->epsilon->alpha' PHASE TRANSITION IN IRON

    SciTech Connect (OSTI)

    Belof, J L; Cavallo, R M; Olson, R T; King, R S; Gray, G T; Holtkamp, D B; Chen, S R; Rudd, R E; Barton, N R; Arsenlis, A; Remington, B A; Park, H; Prisbrey, S T; Vitello, P A; Bazan, G; Mikaelian, K O; Comley, A J; Maddox, B R; May, M J

    2011-08-10T23:59:59.000Z

    We present here the first dynamic Rayleigh-Taylor (RT) strength measurement of a material undergoing solid-solid phase transition. Iron is quasi-isentropically driven across the pressure-induced bcc ({alpha}-Fe) {yields} hcp ({var_epsilon}-Fe) phase transition and the dynamic strength of the {alpha}, {var_epsilon} and reverted {alpha}{prime} phases have been determined via proton radiography of the resulting Rayleigh-Taylor unstable interface between the iron target and high-explosive products. Simultaneous velocimetry measurements of the iron free surface yield the phase transition dynamics and, in conjunction with detailed hydrodynamic simulations, allow for determination of the strength of the distinct phases of iron. Forward analysis of the experiment via hydrodynamic simulations reveals significant strength enhancement of the dynamically-generated {var_epsilon}-Fe and reverted {alpha}{prime}-Fe, comparable in magnitude to the strength of austenitic stainless steels.

  1. Effective field theories for inclusive B decays

    E-Print Network [OSTI]

    Lee, Keith S. M. (Keith Seng Mun)

    2006-01-01T23:59:59.000Z

    In this thesis, we study inclusive decays of the B meson. These allow one to determine CKM elements precisely and to search for physics beyond the Standard Model. We use the framework of effective field theories, in ...

  2. The BNL rare kaon decay program

    SciTech Connect (OSTI)

    Littenberg, L.

    1996-12-31T23:59:59.000Z

    The rare kaon decay program at Brookhaven National Laboratory is reviewed. Results from the last round of experiments are briefly discussed. The three experiments currently collecting data are described. Prospects for future experiments are discussed.

  3. Theory of top quark production and decay

    SciTech Connect (OSTI)

    Kuehn, J.H. [Universitaet Karlsruhe (Germany)

    1997-01-01T23:59:59.000Z

    Direct and indirect information on the top quark mass and its decay modes is reviewed. The theory of top production in hadron- and electron-positron-colliders is presented.

  4. Neutrino Decay and Solar Neutrino Seasonal Effect

    E-Print Network [OSTI]

    Picoreti, R; de Holanda, P C; Peres, O L G

    2015-01-01T23:59:59.000Z

    We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the $\

  5. Double beta decay and neutrino mass models

    E-Print Network [OSTI]

    Helo, J C; Ota, T; Santos, F A Pereira dos

    2015-01-01T23:59:59.000Z

    Neutrinoless double beta decay allows to constrain lepton number violating extensions of the standard model. If neutrinos are Majorana particles, the mass mechanism will always contribute to the decay rate, however, it is not a priori guaranteed to be the dominant contribution in all models. Here, we discuss whether the mass mechanism dominates or not from the theory point of view. We classify all possible (scalar-mediated) short-range contributions to the decay rate according to the loop level, at which the corresponding models will generate Majorana neutrino masses, and discuss the expected relative size of the different contributions to the decay rate in each class. We also work out the phenomenology of one concrete 2-loop model in which both, mass mechanism and short-range diagram, might lead to competitive contributions, in some detail.

  6. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    J. J. Gómez-Cadenas; Justo Martín-Albo

    2015-02-25T23:59:59.000Z

    This paper reviews the current status and future outlook of neutrinoless double beta decay searches, which try to provide an answer to the fundamental question of whether neutrinos are Dirac or Majorana particles.

  7. Recent Results in Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Lisa J. Kaufman

    2013-05-14T23:59:59.000Z

    The search for neutrinoless double beta decay is a rich source for new physics. The observation of this decay will lead to understanding of the absolute mass scale of neutrinos, the Majorana nature of the neutrino (whether the neutrino is its own anti-particle), and lepton number violation. Double beta decay is being investigated around the world by several experiments using different candidate isotopes. There has been much progress made in experimental techniques recently such that achieving sensitivity to neutrino masses at 50 meV and below will be possible in the near future. A summary of recent results in neutrinoless double beta decay is discussed with a look toward the experimental goals for the future.

  8. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    Gómez-Cadenas, J J

    2015-01-01T23:59:59.000Z

    This paper reviews the current status and future outlook of neutrinoless double beta decay searches, which try to provide an answer to the fundamental question of whether neutrinos are Dirac or Majorana particles.

  9. Electrical Analogs of Atomic Radiative Decay Processes

    E-Print Network [OSTI]

    Fontana, Peter R.; Srivastava, Rajendra P.

    1977-03-01T23:59:59.000Z

    Simple electrical circuits are analyzed, and the results show that for high frequencies they have frequency and time responses identical to the spontaneous radiative decays of atoms. As an illustration of the analogy a two-circuit electrical system...

  10. Can Dark Matter Decay in Dark Energy?

    E-Print Network [OSTI]

    S. H. Pereira; J. F. Jesus

    2009-02-26T23:59:59.000Z

    We analyze the interaction between Dark Energy and Dark Matter from a thermodynamical perspective. By assuming they have different temperatures, we study the possibility of occurring a decay from Dark Matter into Dark Energy, characterized by a negative parameter $Q$. We find that, if at least one of the fluids has non vanishing chemical potential, for instance $\\mu_x0$, the decay is possible, where $\\mu_x$ and $\\mu_{dm}$ are the chemical potentials of Dark Energy and Dark Matter, respectively. Using recent cosmological data, we find that, for a fairly simple interaction, the Dark Matter decay is favored with a probability of $\\sim 93%$ over the Dark Energy decay. This result comes from a likelihood analysis where only background evolution has been considered.

  11. New Physics Effects From B Meson Decays

    E-Print Network [OSTI]

    Anirban Kundu

    2000-03-23T23:59:59.000Z

    In this talk, we point out some of the present and future possible signatures of physics beyond the Standard Model from B-meson decays, taking R-parity conserving and violating supersymmetry as illustrative examples.

  12. CP Violation in Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    T. Fukuyama; K. Matsuda; H. Nishiura

    1997-08-19T23:59:59.000Z

    We argue three-flavour neutrino mixing. We consider the neutrinos as Majorana particles and see how the neutrinoless double beta decay constrains the neutrino mixing angles. Our formulation is widely valid and is applied to the neutrino oscillation experiment.

  13. pp, pA and. cap alpha cap alpha. collisions and the understanding of the quark-gluon plasma

    SciTech Connect (OSTI)

    Geist, W.M.

    1988-06-01T23:59:59.000Z

    Global characteristics of heavy ion collisions at high energy are now understood at some level such that the challenging search for Quark-Gluon plasma signatures becomes of more importance. Some features of pp, pA, and ..cap alpha../ alpha/ interactions at ..sqrt..s less than or equal to 62 GeV are selected to illustrate potential consequences for, and problems of, investigations of the Quark-Gluon plasma. 35 refs., 8 figs.

  14. Non-standard semileptonic hyperon decays

    E-Print Network [OSTI]

    Hsi-Ming Chang; Martin González-Alonso; Jorge Martin Camalich

    2015-03-05T23:59:59.000Z

    We investigate the discovery potential of semileptonic hyperon decays in terms of searches of new physics at teraelectronvolt scales. These decays are controlled by a small $SU(3)$-flavor breaking parameter that allows for systematic expansions and accurate predictions in terms of a reduced dependence on hadronic form factors. We find that muonic modes are very sensitive to non-standard scalar and tensor contributions and demonstrate that these could provide a powerful synergy with direct searches of new physics at the LHC.

  15. Fidelity Decay for Phase Space Displacements

    E-Print Network [OSTI]

    Diego V. Bevilaqua; Eric J. Heller

    2004-09-03T23:59:59.000Z

    In this letter we analyse the behavior of fidelity decay under a very specific kind of perturbation: phase space displacements. Under these perturbations, systems will decay following the Lyapunov regime only. Others universal regimes discussed in the literature are not presented in this case; instead, for small values of the perturbation we observe quantum freeze of the fidelity. We also show that it is possible to connect this result with the incoherent neutron scattering problem

  16. Vacuum decay in a soluble model

    SciTech Connect (OSTI)

    Ferraz de Camargo F, A.; Shellard, R.C.; Marques, G.C.

    1984-03-15T23:59:59.000Z

    We study a field-theoretical model where the decay rate of the false vacuum can be computed up to the first quantum corrections in both the high-temperature and zero-temperature limits. We find that the dependence of the decay rate on the height and width of the potential barrier does not follow the same simple area rule as in the quantum-mechanical case. Furthermore, its behavior is strongly model dependent.

  17. Neutrinoless double beta decay with scalar bilinears

    E-Print Network [OSTI]

    H. V. Klapdor-Kleingrothaus; U. Sarkar

    2002-11-18T23:59:59.000Z

    One possible probe to physics beyond the standard model is to look for scalar bilinears, which couple to two fermions of the standard model. We point out that the scalar bilinears allow new diagrams contributing to the neutrinoless double beta decay. The upper bound on the neutrinoless double beta decay lifetime would then give new constraints on the ratio of the masses of these scalars to their couplings to the fermions.

  18. Searches for neutrinoless double beta decay

    E-Print Network [OSTI]

    B. Schwingenheuer

    2012-01-24T23:59:59.000Z

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.

  19. Rare meson decays into very light neutralinos

    SciTech Connect (OSTI)

    O'Leary, Ben [Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany)

    2010-02-10T23:59:59.000Z

    Results are presented for the two-body decays of mesons into light neutralinos and from the first complete calculation of the loop-induced decays of kaons to pions plus light neutralinos and of B mesons to kaons plus light neutralinos. The branching ratios are shown to be strongly suppressed within the MSSM with minimal flavor violation, and no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed.

  20. False Starts in History of Searches for 2{beta} Decay, or Discoverless Double Beta Decay

    SciTech Connect (OSTI)

    Tretyak, V. I. [Institute for Nuclear Research, MSP 03680, Kyiv (Ukraine)

    2011-12-16T23:59:59.000Z

    A collection of stories is presented on discoveries of 2{beta} decay (including neutrinoless one) which were refuted in the subsequent investigations.

  1. Influence of Magnolol on the bystander effect induced by alpha-particle irradiation

    E-Print Network [OSTI]

    Yu, K.N.

    . Introduction Alpha particles emitted from radon and radon progeny contribute the main part of the natural

  2. Calculated final state probability distributions for T2 -decay measurements

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.6.1 Neutrinoless double beta decay . . . . . . . . . . . . . . . . . . . . 19 1.6.2 Cosmological

  3. Ratios of heavy hadron semileptonic decay rates

    E-Print Network [OSTI]

    Michael Gronau; Jonathan L. Rosner

    2010-12-27T23:59:59.000Z

    Ratios of charmed meson and baryon semileptonic decay rates appear to be satisfactorily described by considering only the lowest-lying (S-wave) hadronic final states and assuming the kinematic factor describing phase space suppression is the same as that for free quarks. For example, the rate for $D_s$ semileptonic decay is known to be $(17.0 \\pm 5.3)%$ lower than those for $D^0$ or $D^+$, and the model accounts for this difference. When applied to hadrons containing $b$ quarks, this method implies that the $B_s$ semileptonic decay rate is about 1% higher than that of the nonstrange $B$ mesons. This small difference thus suggests surprisingly good local quark-hadron duality for $B$ semileptonic decays, complementing the expectation based on inclusive quark-hadron duality that these differences in rates should not exceed a few tenths of a percent. For $\\Lambda_b$ semileptonic decay, however, the inclusive rate is predicted to be about 13% greater than that of the nonstrange $B$ mesons. This value, representing a considerable departure from a calculation using a heavy quark expansion, is close to the corresponding experimental ratio $\\Gamma(\\Lambda_b)/ \\bar \\Gamma(B) = 1.13 \\pm 0.03$ of total decay rates.

  4. Measurements of DT alpha particle loss near the outer midplane of TFTR

    SciTech Connect (OSTI)

    Zweben, S.J.; Darrow, D.S.; Herrmann, H.W.; Redi, M.H.; Schivell, J.; White, R.B.

    1995-07-01T23:59:59.000Z

    Measurements of DT alpha particle loss to the outer midplane region of TFTR have been made using a radially movable scintillator detector. The conclusion from this data is that mechanisms determining the DT alpha loss to the outer midplane are not substantially different from those for DD fusion products. Some of these results are compared with a simplified theoretical model for TF ripple-induced alpha loss, which is expected to be the dominant classical alpha loss mechanism near the outer midplane. An example of plasma-driven MHD-induced alpha particle loss is shown, but no signs of any ``collective`` alpha instability-induced alpha loss have yet been observed.

  5. Systematic examination of the impact of pre-stimulus alpha- mu and gamma band oscillations on perception : correlative and causal manipulation in mouse and human

    E-Print Network [OSTI]

    Pritchett, Dominique L. (Dominique Leon)

    2012-01-01T23:59:59.000Z

    The over-arching hypothesis that drives my work is that neural dynamics, fluctuating on millisecond to second time scales, powerfully impact perception. In this thesis, I employ correlative electrophysiological recording ...

  6. alpha particle detection: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    its potential application in two-phase xenon detectors for dark matter and neutrinoless double beta decay experiments. The study is carried out in pure xenon at room temperature....

  7. Utility of extracting {alpha}-particle energy by waves

    SciTech Connect (OSTI)

    Fisch, N.J.; Herrmann, M.C.

    1994-05-01T23:59:59.000Z

    The utility of extracting {alpha}-particle power, and then diverting this power to fast fuel ions, is investigated. As power is diverted to fast ions and then to ions, a number of effects come into play, as the relative amounts of pressure taken up by electrons, fuel ions, and fast {alpha}-particles shift. In addition, if the {alpha}-particle power is diverted to fast fuel ions, there is an enhanced fusion reactivity because of the nonthermal component of the ion distribution. Some useful expressions for describing these effects are derived, and it is shown that fusion reactors with power density about twice what otherwise might be obtained can be contemplated, so long as a substantial amount of the {alpha}-particle power can be diverted. Interestingly, in this mode of operation, once the electron heat is sufficiently confined, further improvement in confinement is actually not desirable. A similar improvement in fusion power density can be obtained for advanced fuel mixtures such as D-He{sup 3}, where the power of both the energetic {alpha}-particles and the energetic protons might be diverted advantageously.

  8. Alpha-beta coordination method for collective search

    DOE Patents [OSTI]

    Goldsmith, Steven Y. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    The present invention comprises a decentralized coordination strategy called alpha-beta coordination. The alpha-beta coordination strategy is a family of collective search methods that allow teams of communicating agents to implicitly coordinate their search activities through a division of labor based on self-selected roles and self-determined status. An agent can play one of two complementary roles. An agent in the alpha role is motivated to improve its status by exploring new regions of the search space. An agent in the beta role is also motivated to improve its status, but is conservative and tends to remain aggregated with other agents until alpha agents have clearly identified and communicated better regions of the search space. An agent can select its role dynamically based on its current status value relative to the status values of neighboring team members. Status can be determined by a function of the agent's sensor readings, and can generally be a measurement of source intensity at the agent's current location. An agent's decision cycle can comprise three sequential decision rules: (1) selection of a current role based on the evaluation of the current status data, (2) selection of a specific subset of the current data, and (3) determination of the next heading using the selected data. Variations of the decision rules produce different versions of alpha and beta behaviors that lead to different collective behavior properties.

  9. 3alpha clustering in the excited states of 16C

    E-Print Network [OSTI]

    T. Baba; Y. Chiba; M. Kimura

    2014-10-03T23:59:59.000Z

    The alpha cluster states of 16C are investigated by using the antisymmetrized molecular dynamics. It is shown that two different types of alpha cluster states exist: triangular and linear-chain states. The former has an approximate isosceles triangular configuration of alpha particles surrounded by four valence neutrons occupying sd-shell, while the latter has the linearly aligned alpha particles with two sd-shell neutrons and two pf-shell neutrons. It is found that the structure of the linear-chain state is qualitatively understood in terms of the 3/2 pi- and 1/2 sigma- molecular orbit as predicted by molecular-orbital model, but there exists non-negligible Be+alpha+2n correlation. The band-head energies of the triangular and linear-chain rotational bands are 8.0 and 15.5 MeV, and the latter is close to the He+Be threshold energy. It is also shown that the linear-chain state becomes the yrast sstate at J=10 with excitation energy 27.8 MeV owing to its very large moment-of-inertia comparable with hyperdeformation.

  10. DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs

    E-Print Network [OSTI]

    Lee, Hsien-Hsin "Sean"

    DRAM Decay: Using Decay Counters to Reduce Energy Consumption in DRAMs Mrinmoy Ghosh Hsien-Hsin S. Lee School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta, GA 30332 technology they use. For each refresh in a DRAM row, the stored information in each cell is read out

  11. Neutrino Decay and Neutrinoless Double Beta Decay in a 3-3-1 Model

    E-Print Network [OSTI]

    Alex G. Dias; A. Doff; C. A. de S. Pires; P. S. Rodrigues da Silva

    2005-08-11T23:59:59.000Z

    In this work we show that the implementation of spontaneous breaking of the lepton number in the 3-3-1 model with right-handed neutrinos gives rise to fast neutrino decay with majoron emission and generates a bunch of new contributions to the neutrinoless double beta decay.

  12. Neutrino decay and neutrinoless double beta decay in a 3-3-1 model

    SciTech Connect (OSTI)

    Dias, Alex G. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66.318, 05315-970, Sao Paulo-SP (Brazil); Doff, A. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145, 01405-900 Sao Paulo-SP (Brazil); Pires, C.A. de S; Rodrigues da Silva, P.S. [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-970, Joao Pessoa-PB (Brazil)

    2005-08-01T23:59:59.000Z

    In this work we show that the implementation of spontaneous breaking of the lepton number in the 3-3-1 model with right-handed neutrinos gives rise to fast neutrino decay with Majoron emission and generates a bunch of new contributions to the neutrinoless double beta decay.

  13. Hyperfine-induced effects on the linear polarization of the K$\\alpha_1$ emission from helium-like ions

    E-Print Network [OSTI]

    Surzhykov, Andrey; Stöhlker, Thomas; Fritzsche, Stephan

    2013-01-01T23:59:59.000Z

    The linear polarization of the characteristic photon emission from few-electron ions is studied for its sensitivity with regard to the nuclear spin and magnetic moment of the ions. Special attention is paid, in particular, to the K$\\alpha_1$ ($1s 2p_{3/2} ^{1,3}P_{1,2} \\to 1s^2 ^1S_0$) decay of selected helium-like ions following the radiative electron capture into initially hydrogen-like species. Based on the density matrix theory, a unified description is developed that includes both, the many-electron and hyperfine interactions as well as the multipole-mixing effects arising from the expansion of the radiation field. It is shown that the polarization of the K$\\alpha_1$ line can be significantly affected by the mutipole mixing between the leading $M2$ and hyperfine-induced $E1$ components of $1s2p ^3P_2, F_i \\to 1s^2 ^1S_0, F_f$ transitions. This $E1$-$M2$ mixing strongly depends on the nuclear properties of the considered isotopes and can be addressed experimentally at existing heavy-ion storage rings.

  14. The search for neutrinoless double beta decay

    E-Print Network [OSTI]

    J. J. Gomez-Cadenas; J. Martin-Albo; M. Mezzetto; F. Monrabal; M. Sorel

    2012-01-16T23:59:59.000Z

    In the last two decades the search for neutrinoless double beta decay has evolved into one of the highest priorities for understanding neutrinos and the origin of mass. The main reason for this paradigm shift has been the discovery of neutrino oscillations, which clearly established the existence of massive neutrinos. An additional motivation for conducting such searches comes from the existence of an unconfirmed, but not refuted, claim of evidence for neutrinoless double decay in $^{76}\\text{Ge}$. As a consequence, a new generation of experiments, employing different detection techniques and $\\beta\\beta$ isotopes, is being actively promoted by experimental groups across the world. In addition, nuclear theorists are making remarkable progress in the calculation of the neutrinoless double beta decay nuclear matrix elements, thus eliminating a substantial part of the theoretical uncertainties affecting the particle physics interpretation of this process. In this report, we review the main aspects of the double beta decay process and some of the most relevant experiments. The picture that emerges is one where searching for neutrinoless double beta decay is recognized to have both far-reaching theoretical implications and promising prospects for experimental observation in the near future.

  15. FAST-RESPONSE ISOTOPIC ALPHA CONTINUOUS AIR MONITOR (CAM)

    SciTech Connect (OSTI)

    Keith D. Patch

    2000-04-28T23:59:59.000Z

    The objective of this effort is to develop and test a novel Continuous Air Monitor (CAM) instrument for monitoring alpha-emitting radionuclides, using a technology that can be applied to Continuous Emission Monitoring (CEM) of thermal treatment system off gas streams. The CAM instrument will have very high alpha spectral resolution and provide real-time, on-line monitoring suitable for alerting workers of high concentrations of alpha-emitting radionuclides in the ambient air and for improved control of decontamination, dismantlement, and air emission control equipment. Base Phase I involves the design, development, and preliminary testing of a laboratory-scale instrument. Testing will initially be conducted using naturally-occurring radon progeny in ambient air. In the Optional Phase II, the Base Phase I instrument will be critically evaluated at the Lovelace Respiratory Research Institute (LRRI) with characterized plutonium aerosols; then an improved instrument will be built and field-tested at a suitable DOE site.

  16. Beamed Lyman Alpha Emission through Outflow-Driven Cavities

    E-Print Network [OSTI]

    Behrens, Christoph; Niemeyer, Jens

    2014-01-01T23:59:59.000Z

    We investigate the radiative transfer of Lyman alpha photons through simplified anisotropic gas distributions, which represent physically motivated extensions of the popular 'shell-models'. Our study is motivated by the notion that (i) shell models do not always reproduce observed Lyman alpha spectral line profiles, (ii) (typical) shell models do not allow for the escape of ionizing photons, and (iii) the observation & expectation that winds are more complex, anisotropic phenomena. We examine the influence of inclination on the Lyman alpha spectra, relative fluxes and escape fractions. We find the flux to be enhanced/suppressed by factors up to a few depending on the parameter range of the models, corresponding to a boost in equivalent width of the same amplitude if we neglect dust. In general, lower mean optical depths tend to reduce the impact of anisotropies as is expected. We find a correlation between an observed peak in the -- occasionally triple-peaked -- spectrum at the systemic velocity and the e...

  17. Experimental Investigation of Weak Non-Mesonic Decay of 10Be(Lambda)Hypernuclei at CEBAF

    E-Print Network [OSTI]

    S. Majewski; L. Majling; A. Margaryan; L. Tang

    2005-08-05T23:59:59.000Z

    Hypernuclei are convenient laboratory to study the baryon-baryon weak interaction and associated effective Hamiltonian. The strangeness changing process, in which a Lambda hyperon converts to a neutron with a release up to 176 MeV, provides a clear signal for a conversion of an s-quark to a d-quark. We propose to perform a non-mesonic weak decay study of 10Be(Lambda)hypernuclei using the (e,eK) reaction. These investigations will fully utilize the unique parameters of the CEBAF CW electron beam and RF system and are enabled by (1) the use of new detector for alpha particles based on the recently developed RF timing technique with picosecond resolution and (2) the small angle and large acceptance kaon spectrometer-HKS in Hall C.

  18. Logarithmic decay in single-particle relaxations of hydrated lysozyme powder

    E-Print Network [OSTI]

    Marco Lagi; Piero Baglioni; Sow-Hsin Chen

    2009-08-13T23:59:59.000Z

    We present the self-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular dynamics (MD) simulations. The self-intermediate scattering functions (SISF) of the amino acid residue center-of-mass and of the protein hydrogen atoms display a logarithmic decay over 3 decades of time, from 2 picoseconds to 2 nanoseconds, followed by an exponential alpha-relaxation. This kind of slow dynamics resembles the relaxation scenario within the beta-relaxation time range predicted by the mode coupling theory (MCT) in the vicinity of higher-order singularities. These results suggest a strong analogy between the single-particle dynamics of the protein and the dynamics of colloidal, polymeric and molecular glass-forming liquids.

  19. The HI Properties and Environment of Lyman-alpha Absorbers

    E-Print Network [OSTI]

    J. L. Rosenberg

    2005-04-20T23:59:59.000Z

    We present results from two projects in which we have used the HI 21cm emission line as a tracer of gas-rich galaxy populations in the vicinity of Lyman-alpha absorbers. In the first case, we examine the HI environment of SBS 1543+593, the nearest damped Lyman-alpha absorber. We use a VLA map of the region around this LSB galaxy which itself shows an extended HI disk to identify 3 gas rich neighbors within 185 kpc. While it is not clear whether we should expect local damped Lyman-alpha systems to reside in such gas-rich regions, we would expect this kind of environment to be more prevalent at higher redshifts where less of the gas is in the dense inner regions of galaxies or has been consumed by star formation. This local galaxy is the only system in which we can study the gaseous environment in this kind of detail. In the second case, we examine the HI environment surrounding 16 Lyman-alpha forest absorbers along 4 QSO sightlines. We do not detect any gas-rich galaxies at the absorber positions indicating that, at least down to our sensitivity limits, these absorption lines do not seem to be associated with galaxy halos. For half of the Lyman-alpha absorption systems there is a galaxy within 500 kpc, but for the other half there is not. In two cases there is no galaxy within 2 Mpc of the Lyman-alpha absorption systems indicating that absorbers do, in some cases, reside in voids.

  20. Lyman alpha Transfer in a thick, dusty, and static medium

    E-Print Network [OSTI]

    Sang-Hyeon Ahn; Hee-Won Lee; Hyung-Mok Lee

    2000-06-13T23:59:59.000Z

    We developed a Monte Carlo code that describes the resonant Lyman alpha line transfer in an optically thick, dusty, and static medium. The code was tested against the analytic formula derived by Neufeld (1990). We explain the line transfer mechanism for a wide range of line center optical depths by tracing histories of photons in the medium. We find that photons escape from the medium by a series of wing scatterings, during which polarization may develop. We applied our code to examine the amount of dust extinction around the Lyman alpha in primeval galaxies. Brief discussions on the astrophysical application of our work are presented.

  1. First-principles elastic properties of (alpha)-Pu

    SciTech Connect (OSTI)

    Soderlind, P; Klepeis, J

    2009-02-18T23:59:59.000Z

    Density-functional electronic-structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic antiferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functional. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from recent resonant ultrasound spectroscopy for a cast sample is made.

  2. First-principles elastic properties of (alpha)-Pu

    SciTech Connect (OSTI)

    Soderlind, P; Klepeis, J E

    2008-11-04T23:59:59.000Z

    Density-functional electronic structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic anti-ferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functionals. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from resonant ultrasound spectroscopy for a cast sample is made.

  3. The effects of alpha particle irradiation on stainless steel

    E-Print Network [OSTI]

    Shipp, John Douglas

    1999-01-01T23:59:59.000Z

    and an approximation based on the first year's fluence. . . . . . . . . 17 CHAPTER I INTRODUCTION The storage of Weapons Grade Plutonium (WGPu) pits has prompted this study of the effects of alpha particle irradiation on stainless steel. Previous studies of alpha... and properties of WGPu. ISOTOPE Pu-239 Pu-240 P0-241 Density* Crystal Structure* ATOMIC ABD. (/o) 94. 0 5. 8 0. 2 15. 7 g/cm' BCC 'Note: The density and crystal structure of elemental plutonium is 19. 7 g/cm' and FCC, respectively...

  4. Standoff alpha radiation detection via excited state absorption of air

    SciTech Connect (OSTI)

    Yao, Jimmy; Yin, Stuart Shizhuo [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Brenizer, Jack [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Hui, Rongqing [Department of Electrical Engineering and Computer Science, The University of Kansas, Lawrence, Kansas 66045 (United States)] [Department of Electrical Engineering and Computer Science, The University of Kansas, Lawrence, Kansas 66045 (United States)

    2013-06-24T23:59:59.000Z

    A standoff alpha radiation detection technique based on the physical mechanism of excited state absorption of air molecules was explored and is presented in this paper. Instead of directly detecting the radiation via measuring the intensity of radiation induced air fluorescence, the radiation is detected via the excited state absorption of alpha radiation excited/ionized air molecules. Both theoretical analyses and experimental verifications were conducted. The experimental results confirmed that the radiation could be detected via excited state absorption of radiation excited/ionized air molecules at a 10 m standoff distance, which was consistent with the theoretical analyses.

  5. Proton decay in the super-world

    SciTech Connect (OSTI)

    Raby, S.

    1986-01-01T23:59:59.000Z

    Predictions are elaborated for nucleon decay in supersymmetric grand unified theories (SUSY GUT's). A minimal SU/sub 5/ SUSY GUT is described, as well as SU/sub 5/ breaking. The low energy theory and breaking of supersymmetry are discussed. It is concluded that nucleon decay in SUSY GUT's would be dominated by p ..-->.. K/sup +/anti nu/sub ..mu../ and n ..-->.. K/sup 0/anti nu/sub ..mu../. There are ranges in parameter space for which other decay modes may be significant or may even dominate, it is found. It is noted that minimal SUSY GUT's typically predict a value of sin/sup 2/theta/sub w/ of order .233. 20 refs., 7 figs. (LEW)

  6. Rare K decays: Challenges and Perspectives

    E-Print Network [OSTI]

    Christopher Smith

    2014-09-22T23:59:59.000Z

    At this stage of the LHC program, the prospect for a new physics signal in the very rare K ---> pi nu nu bar decays may be dented, but remains well alive thanks to their intrinsic qualities. First, these decays are among the cleanest observables in the quark flavor sector. When combined with their terrible suppression in the Standard Model, they thus offer uniquely sensitive probes. Second, the LHC capabilities are not ideal for all kinds of new physics, even below the TeV scale. For example, rather elusive scenarios like natural-SUSY-like hierarchical spectrum, baryon number violation, or new very light but very weakly interacting particles may well induce deviations in rare K decays. Even though experimentalists should brace themselves for tiny deviations, these modes thus have a clear role to play in the LHC era.

  7. Inclusive radiative {psi}(2S) decays

    SciTech Connect (OSTI)

    Libby, J.; Martin, L.; Powell, A.; Thomas, C.; Wilkinson, G. [University of Oxford, Oxford OX1 3RH (United Kingdom); Mendez, H. [University of Puerto Rico, Mayaguez, Puerto Rico 00681 (Puerto Rico); Ge, J. Y.; Miller, D. H.; Shipsey, I. P. J.; Xin, B. [Purdue University, West Lafayette, Indiana 47907 (United States); Adams, G. S.; Hu, D.; Moziak, B.; Napolitano, J. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ecklund, K. M. [Rice University, Houston, Texas 77005 (United States); He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H. [University of Rochester, Rochester, New York 14627 (United States)] (and others)

    2009-10-01T23:59:59.000Z

    Using e{sup +}e{sup -} collision data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decay {psi}(2S){yields}{gamma}gg. We determine the ratio of the inclusive direct photon decay rate to that of the dominant three-gluon decay rate {psi}(2S){yields}ggg (R{sub {gamma}}{identical_to}{gamma}({gamma}gg)/{gamma}(ggg)) to be R{sub {gamma}}(z{sub {gamma}}>0.4)=0.070{+-}0.002{+-}0.019{+-}0.011, with z{sub {gamma}} defined as the scaled photon energy relative to the beam energy. The errors shown are statistical, systematic, and that due to the uncertainty in the input branching fractions used to extract the ratio, respectively.

  8. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    M. Hirsch

    2006-09-15T23:59:59.000Z

    Neutrinoless double beta decay violates lepton number by two units, a positive observation therefore necessarily implies physics beyond the standard model. Here, three possible contributions to neutrinoless double beta decay are briefly reviewed: (a) The mass mechanism and its connection to neutrino oscillations; (b) Left-right symmetric models and the lower limit on the right-handed W boson mass; and (c) R-parity violating supersymmetry. In addition, the recently published ``extended black box'' theorem is briefly discussed. Combined with data from oscillation experiments this theorem provides proof that the neutrinoless double beta decay amplitude must receive a non-zero contribution from the mass mechanism, if neutrinos are indeed Majorana particles.

  9. Correlations and the neutrinoless double beta decay

    SciTech Connect (OSTI)

    Menendez, J.; Poves, A. [Departamento de Fisica Teorica, and IFT, UAM-CSIC, Universidad Autonoma de Madrid, 28049-Madrid (Spain); Caurier, E.; Nowacki, F. [IPHC, IN2P3-CNRS/Universite Louis Pasteur, 67037-Strasbourg (France)

    2009-11-09T23:59:59.000Z

    We explore the influence of the deformation on the nuclear matrix elements of the neutrinoless double beta decay (NME), concluding that the difference in deformation -or more generally on the amount of quadrupole correlations- between parent and grand daughter nuclei quenchs strongly the decay. We discuss how varies the nuclear matrix element of {sup 76}Ge decay when the wave functions of the two nuclei involved in the transition are constrained to reproduce the experimental occupancies. In the Interacting Shell Model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%, thus, the discrepancies between both approaches diminish.

  10. Review of New Rare Hadronic B-decay Results

    E-Print Network [OSTI]

    James G. Smith

    2006-06-01T23:59:59.000Z

    We present a new result from Belle and many new results from BABAR for rare hadronic B decays. These include measurements of decays involving baryons, a Dalitz plot analysis of the three-charged-kaon system, many new results for B decays to eta'X and omegaX, and a limit for the decay B-> a_1 rho. Measurements of the vector-vector decays B->rhoKstar and B->omegaKstar are helping to understand the value of the longitudinal polarization fraction for these B->VV decays.

  11. Neutrinoless double beta decay and nuclear matrix elements

    SciTech Connect (OSTI)

    Simkovic, Fedor [BLTP, JINR Dubna, 141980 Dubna, Moscow region (Russian Federation); Comenius University, Mlynska dolina, Bratislava (Slovakia)

    2011-11-23T23:59:59.000Z

    The fundamental importance of searching for neutrinoless double-beta decay (0{nu}{beta}{beta}-decay) is widely recognized. Observation of the decay would tell us that the total lepton number is not conserved and that, consequently, neutrinos are massive Majorana fermions. The 0{nu}{beta}{beta}-decay is discussed in context of neutrino oscillation data. The perspectives of the experimental 0{nu}{beta}{beta}-decay searches are analyzed. The importance of reliable determination of the 0{nu}{beta}{beta}-decay nuclear matrix elements is pointed out.

  12. Simulated progress in double-beta decay

    SciTech Connect (OSTI)

    Miley, H.S.; Arthur, R.J. [Pacific Northwest Lab., Richland, WA (United States); Avignone, F.T. [South Carolina Univ., Columbia, SC (United States)] [and others

    1993-09-01T23:59:59.000Z

    A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete {sup 100}Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 {mu}Bq/g of {sup 210}Pb in lead shielding were obtained.

  13. Lattice String Breaking and Heavy Meson Decays

    E-Print Network [OSTI]

    I T Drummond; R R Horgan

    1998-11-11T23:59:59.000Z

    We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from the decay rate for $\\Upsilon(4S)\\to B{\\bar B}$. We extend the calculation to achieve rough estimates for the contributions of channels involving $B, B^*, B_s and B_s^*$ mesons to the width of the $\\Upsilon(5S)$.

  14. Observation of ?cJ decays to ??¯¯¯????

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ablikim, M.; Achasov, M. N.; Ambrose, D. J.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; et al

    2012-09-01T23:59:59.000Z

    Decays of the ?cJ states (J=0, 1, 2) to ??¯¯¯????, including processes with intermediate ?(1385), are studied through the E1 transition ?'???cJ using 106×10? ?' events collected with the BESIII detector at BEPCII. This is the first observation of ?cJ decays to the final state ??¯¯¯????. The branching ratio of the intermediate process ?cJ??(1385)±?¯¯¯(1385)? is also measured for the first time, and the results agree with the theoretical predictions based on the color-octet effect.

  15. Gravitational decay of the Z boson

    SciTech Connect (OSTI)

    Nieves, Jose F.; Pal, Palash B. [Laboratory of Theoretical Physics, Department of Physics, P.O. Box 23343, University of Puerto Rico, Rio Piedras, 00931-3343 (Puerto Rico); Saha Institute of Nuclear Physics, 1/AF Bidhan-Nagar, Calcutta 700064 (India)

    2005-11-01T23:59:59.000Z

    We study the decay process of the Z boson to a photon and a graviton. The most general form of the on-shell amplitude, subject to the constraints due to the conservation of the electromagnetic current and the energy-momentum tensor, is determined. The amplitude is expressed in terms of three form factors, two of which are CP odd while one is CP even. The latter, which is the only nonzero form factor at the one-loop level, is computed in the standard model and the decay rate is determined.

  16. Attractor Explosions and Catalyzed Vacuum Decay

    SciTech Connect (OSTI)

    Green, Daniel; Silverstein, Eva; Starr, David

    2006-05-05T23:59:59.000Z

    We present a mechanism for catalyzed vacuum bubble production obtained by combining moduli stabilization with a generalized attractor phenomenon in which moduli are sourced by compact objects. This leads straightforwardly to a class of examples in which the Hawking decay process for black holes unveils a bubble of a different vacuum from the ambient one, generalizing the new endpoint for Hawking evaporation discovered recently by Horowitz. Catalyzed vacuum bubble production can occur for both charged and uncharged bodies, including Schwarzschild black holes for which massive particles produced in the Hawking process can trigger vacuum decay. We briefly discuss applications of this process to the population and stability of metastable vacua.

  17. SU(3) Sum Rules for Charm Decay

    E-Print Network [OSTI]

    Yuval Grossman; Dean J Robinson

    2012-11-14T23:59:59.000Z

    We present flavor SU(3) sum rules for $D \\to PP$ and $D \\to PV$ decay amplitudes, that are valid to second order in symmetry breaking by the strange quark mass spurion. Decay rate sum rules are also computed to this order. Particular attention is given to sum rules arising from the isospin and U-spin subgroups, the former providing sensitive tests for alternative sources of SU(3) breaking. We apply the latter together with the postulated $\\Delta U = 0$ rule for the large penguin picture to predict the ratio and difference of the direct CP asymmetries for $D \\to KK^*$ and $D \\to \\pi \\rho$.

  18. Quantum gravitational proton decay at high temperature

    E-Print Network [OSTI]

    Ulf H. Danielsson

    2005-12-29T23:59:59.000Z

    One of the most important challenges of contemporary physics is to find experimental signatures of quantum gravity. It is expected that quantum gravitational effects lead to proton decay but on time scales way beyond what is of any relevance to experiments. At non-zero temperatures there are reasons to believe that the situation is much more favourable. We will argue that at the temperatures and densities reached at present and future fusion facilities there is a realistic possibility that proton decay could be detectable.

  19. The double-beta decay: Theoretical challenges

    SciTech Connect (OSTI)

    Horoi, Mihai [Department of Physics, Central Michigan University, Mount Pleasant, Michigan, 48859 (United States)

    2012-11-20T23:59:59.000Z

    Neutrinoless double beta decay is a unique process that could reveal physics beyond the Standard Model of particle physics namely, if observed, it would prove that neutrinos are Majorana particles. In addition, it could provide information regarding the neutrino masses and their hierarchy, provided that reliable nuclear matrix elements can be obtained. The two neutrino double beta decay is an associate process that is allowed by the Standard Model, and it was observed for about ten nuclei. The present contribution gives a brief review of the theoretical challenges associated with these two process, emphasizing the reliable calculation of the associated nuclear matrix elements.

  20. Neutrinoless double beta decay and neutrino masses

    SciTech Connect (OSTI)

    Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2012-07-27T23:59:59.000Z

    Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.