National Library of Energy BETA

Sample records for milliseconds alpha decay

  1. 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

    2013-01-01

    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.

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

    E-Print Network [OSTI]

    V. Yu. Denisov; H. Ikezoe

    2005-10-27

    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.

  3. Nuclear isospin asymmetry in $\\alpha$ decays of heavy nuclei

    E-Print Network [OSTI]

    Shin, Eunkyoung; Hyun, Chang Ho; Oh, Yongseok

    2015-01-01

    The effects of nuclear isospin asymmetry on $\\alpha$ decay lifetimes of heavy nuclei are investigated within various phenomenological models of nuclear potential for the $\\alpha$ particle. We consider the widely used simple square well potential and Woods-Saxon potential, and modify them by including an isospin asymmetry term. We then suggest a model for the potential of the $\\alpha$ particle motivated by a microscopic phenomenological approach of the Skyrme force model, which naturally introduce the isospin dependent form of the nuclear potential for the $\\alpha$ particle. The empirical $\\alpha$ decay lifetime formula of Viola and Seaborg is also modified to include isospin asymmetry effects. The obtained $\\alpha$ decay half-lives are in good agreement with the experimental data and we find that including the nuclear isospin effects somehow improves the theoretical results for $\\alpha$ decay half-lives. The implications of these results are discussed and the predictions on the $\\alpha$ decay lifetimes of sup...

  4. 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

    2012-12-12

    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.

  5. R(s) and hadronic tau-Decays in Order alpha_s^4: technical aspects

    E-Print Network [OSTI]

    P. A. Baikov; K. G. Chetyrkin; J. H. Kühn

    2009-06-16

    We report on some technical aspects of our calculation of alpha_s^4 corrections to R(s) and the semi-leptonic tau decay width [1-3]. We discuss the inner structure of the result as well as the issue of its correctness. We demonstrate recently appeared independent evidence positively testing one of two components of the full result.

  6. $\\alpha_s$ from the updated ALEPH data for hadronic $\\tau$ decays

    E-Print Network [OSTI]

    Boito, Diogo; Maltman, Kim; Osborne, James; Peris, Santiago

    2015-01-01

    We extract the strong coupling $\\alpha_s(m_\\tau^2)$ from the recently updated ALEPH non-strange spectral functions obtained from hadronic $\\tau$ decays. We apply a self-consistent analysis method, first tested in the analysis of OPAL data, to extract $\\alpha_s(m_\\tau^2)$ and non-perturbative contributions. The analysis yields $\\alpha_s^{\\rm FO}(m_\\tau^2)=0.296\\pm0.010 $, using Fixed Order Perturbation Theory (FOPT), and $\\alpha^{\\rm CI}_s(m_\\tau^2)= 0.310\\pm0.014$, using Contour Improved Perturbation Theory (CIPT). The weighted average of these results with those previously obtained from OPAL data give $\\alpha_s^{\\rm FO}(m_\\tau^2)=0.303\\pm 0.009$ and $\\alpha_s^{\\rm CI}(m_\\tau^2)=0.319\\pm 0.012$, which gives, after evolution to the $Z$ boson mass scale, $\\alpha^{\\rm FO}_s(m_Z^2)=0.1165\\pm0.0012 $ and $\\alpha_s^{\\rm CI}(m_Z^2)=0.1185\\pm0.0015 $, respectively. We observe that non-perturbative effects limit the accuracy with which $\\alpha_s$ can be extracted from $\\tau$ decay data.

  7. {alpha} decay of {sup 180,181}Pb

    SciTech Connect (OSTI)

    Andreyev, A. N.; Antalic, S.; Saro, S.; Ackermann, D.; Comas, V. F.; Heinz, S.; Heredia, J. A.; Hessberger, F. P.; Khuyagbaatar, J.; Kojouharov, I.; Kindler, B.; Lommel, B.; Mann, R.; Cocolios, T. E.; Elseviers, J.; Huyse, M.; Duppen, P. Van; Venhart, M.; Franchoo, S.; Hofmann, S.

    2009-11-15

    A detailed {alpha}-decay study of the neutron-deficient isotope {sup 181}Pb has been performed in the complete fusion reaction {sup 40}Ca+{sup 144}Sm{yields}{sup 184}Pb* at the velocity filter SHIP (GSI, Darmstadt). In comparison with the literature, more precise data have been deduced for the I{sup {pi}}=(9/2{sup -}) ground state in this nucleus, which is presumably based on the neutron {nu}h{sub 9/2} spherical orbital. Improved {alpha}-decay data were also measured for {sup 180}Pb.

  8. 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

  9. {alpha} decay and shape coexistence in the {alpha}-rotor model

    SciTech Connect (OSTI)

    Richards, J.D.; Bingham, C.R.; Nazarewicz, W.; Wauters, J.; Berggren, T.; Berggren, T.; Bingham, C.R.; Nazarewicz, W.; Nazarewicz, W.

    1997-09-01

    The particle-plus-rotor model was employed to study the fine structure seen in the {alpha} decay of even-even neutron-deficient nuclei in the Hg-Po region. The configuration mixing resulting from the shape coexistence between well-deformed prolate bands and spherical (or quasirotational oblate) structures in the daughter nuclei was considered. Experimental {alpha}-decay branching ratios are reproduced within one order of magnitude, except for the case of {sup 180}Hg, where the daughter nucleus {sup 176}Pt is expected to be triaxial in its ground state. The effect of configuration mixing on the relative intensities is discussed in detail, together with the sensitivity of results to the choice of the {alpha}-nucleus optical model parameters. {copyright} {ital 1997} {ital The American Physical Society}

  10. {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

    2004-12-01

    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.

  11. Half-lives of $\\alpha$ decay from natural nuclides and from superheavy elements

    E-Print Network [OSTI]

    Qian, Yibin

    2014-01-01

    Recently, experimental researches on the $\\alpha$ decay with long lifetime are one of hot topics in the contemporary nuclear physics [e.g. N. Kinoshita {\\sl et al.} (2012) and J. W. Beeman {\\sl et al.} (2012) ]. In this study, we have systematically investigated the extremely long-lived $\\alpha$-decaying nuclei within a generalized density-dependent cluster model involving the experimental nuclear charge radii. In detail, the important density distribution of daughter nuclei is deduced from the corresponding experimental charge radii, leading to an improved $\\alpha$-core potential in the quantum tunneling calculation of $\\alpha$-decay width. Besides the excellent agreement between theory and experiment, predictions on half-lives of possible candidates for natural $\\alpha$ emitters are made for future experimental detections. In addition, the recently confirmed $\\alpha$-decay chain from $^{294}$117 is well described, including the attractive long-lived $\\alpha$-decaying $^{270}$Db, i.e., a positive step toward...

  12. Alpha-decay Rates of Yb and Gd in Solar Neutrino Detectors

    E-Print Network [OSTI]

    M. Fujiwara; T. Kawabata; P. Mohr

    2002-03-05

    The $\\alpha$-decay rates for the nuclides $^{168,170,171,172,173,174,176}$Yb and $^{148,150,152,154}$Gd have been estimated from transmission probabilities in a systematic $\\alpha$-nucleus potential and from an improved fit to $\\alpha$-decay rates in the rare-earth mass region. Whereas ${\\alpha}$-decay of $^{152}$Gd in natural gadolinium is a severe obstacle for the use of gadolinium as a low-energy solar-neutrino detector, we show that ${\\alpha}$-decay does not contribute significantly to the background in a ytterbium detector. An extremely long ${\\alpha}$-decay lifetime of $^{168}$Yb is obtained from calculation, which may be close to the sensitivity limit in a low-background solar neutrino detector.

  13. 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

  14. 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

    2011-12-30

    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.

  15. 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

    2012-01-01

    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.

  16. Abrupt changes in alpha-decay systematics as a manifestation of collective nuclear modes

    SciTech Connect (OSTI)

    Qi, C.; Liotta, R. J.; Wyss, R. A.; Andreyev, A. N.; Huyse, M.; Van Duppen, P.

    2010-06-15

    An abrupt change in alpha-decay systematics around the N=126 neutron shell closure is discussed. It is explained as a sudden hindrance of the clustering of the nucleons that eventually form the alpha particle. This is because the clustering induced by the pairing mode acting upon the four nucleons is inhibited if the configuration space does not allow a proper manifestation of the pairing collectivity.

  17. A Mathematica Notebook for Alpha Decay Using an Exponentially Diffuse Boundary Potential

    E-Print Network [OSTI]

    Eugene F. Chaffin; Daniel S. Banks

    2002-06-10

    Using the exponentially diffuse boundary potential of Green and Lee (1955), we develop a Mathematica notebook to treat alpha decay by using the complex energy approach of Preston (1947), as modified by Pierronne and Marquez (1978). Our approach allows the potential to change slowly from the well depth of the interior of the nucleus to the top of the Coulomb barrier, rather than the sudden step of the simple square well used by Pierronne and Marquez. Recent interest in possible variation in coupling constants such as the strong coupling alpha_s motivates us to develop this algorithm which can allow numerical study of the variation of the decay constant of a nucleus such as U-238 when the depth of the nuclear potential well changes.

  18. 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

    2006-03-27

    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}.

  19. 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

  20. Anisotropic alpha decay from oriented odd-mass isotopes of some light actinides

    SciTech Connect (OSTI)

    Berggren, T. )

    1994-11-01

    Half-lives and anisotropies in the [alpha] decay of [sup 205,207,209]Rn, [sup 219]Rn, [sup 221]Fr, [sup 227,229]Pa, and [sup 229]U have been calculated using the reaction-theoretical formalism proposed by Jackson and Rhoades-Brown and adapted for axially symmetric deformed nuclei by Berggren and Olanders. The possibility of octupole deformation has been taken into account. In addition, a variant of triaxial octupole deformation has been considered tentatively in the case of [sup 227]Pa and [sup 229]Pa.

  1. 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

    2013-09-15

    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.

  2. Identification of {gamma} rays from {sup 172}Au and {alpha} decays of {sup 172}Au, {sup 168}Ir, and {sup 164}Re

    SciTech Connect (OSTI)

    Hadinia, B.; Cederwall, B.; Andgren, K.; Baeck, T.; Johnson, A.; Khaplanov, A.; Wyss, R.; Page, R. D.; Grahn, T.; Paul, E. S.; Sandzelius, M.; Scholey, C.; Greenlees, P. T.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, J.; Ketelhut, S.; Leino, M.; Nyman, M.

    2009-12-15

    The very neutron deficient odd-odd nucleus {sup 172}Au was studied in reactions of 342 and 348 MeV {sup 78}Kr beams with an isotopically enriched {sup 96}Ru target. The {alpha} decays previously reported for {sup 172}Au were confirmed and the decay chain extended down to {sup 152}Tm through the discovery of a new {alpha}-decaying state in {sup 164}Re[E{sub {alpha}}=5623(10) keV; t{sub 1/2}=864{sub -110}{sup +150} ms; b{sub {alpha}}=3(1)%]. Fine structure in these {alpha} decays of {sup 172}Au and {sup 168}Ir were identified. A new {alpha}-decaying state was also observed and assigned as the ground state in {sup 172}Au[E{sub {alpha}}=6762(10) keV; t{sub 1/2}=22{sub -5}{sup +6} ms]. This decay chain was also correlated down to {sup 152}Tm through previously reported {alpha} decays. Prompt {gamma} rays from excited states in {sup 172}Au have been identified using the recoil-decay tagging technique. The partial level scheme constructed for {sup 172}Au indicates that it has an irregular structure. Possible configurations of the {alpha}-decaying states in {sup 172}Au are discussed in terms of the systematics of nuclei in this region and total Routhian surface calculations.

  3. 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

    2004-04-13

    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).

  4. Decay of C-10 excited states above the 2p+2 alpha threshold and the contribution from "democratic" two-proton emission 

    E-Print Network [OSTI]

    Charity, R. J.; Mercurio, K.; Sobotka, L. G.; Elson, J. M.; Famiano, M.; Banu, A.; Fu, C.; Trache, L.; Tribble, Robert E.

    2007-01-01

    The decay of C-10 excited states to the 2p+2 alpha exit channel has been studied using an E/A=10.7 MeV C-10 beam inelastically scattered from a Be-9 target. Levels associated with two-proton decay to the ground state of Be-8 have been observed...

  5. 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

    2005-12-01

    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}.

  6. A RAPID SPECTROSCOPIC TECHNIQUE FOR DETERMINING THE POTENTIAL ALPHA ENERGY CONCENTRATION OF RADON DECAY PRODUCTS

    E-Print Network [OSTI]

    Revzan, K.L.

    2013-01-01

    Comparison of the Attachment the Decay Products of Radon-220and Radon-222 to Monodispersed Aerosols,". :! _. Aerosol.Kusnetz H.L. , 1956, "Radon Daughters in Mine Atmosphers.

  7. Millisecond Oxidation of Alkanes

    SciTech Connect (OSTI)

    Scott Han

    2011-09-30

    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.

  8. 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

    2013-01-01

    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.

  9. Modeling pulse profiles of accreting millisecond pulsars

    E-Print Network [OSTI]

    Juri Poutanen

    2008-09-14

    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.

  10. Event counting alpha detector

    DOE Patents [OSTI]

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

    1996-08-27

    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.

  11. Event counting alpha detector

    DOE Patents [OSTI]

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

    1996-01-01

    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.

  12. 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.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; 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

    2009-10-30

    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.

  13. Complete three-loop QCD corrections to the decay H -> ??

    E-Print Network [OSTI]

    P. Maierhöfer; P. Marquard

    2012-12-26

    We present the result for the three-loop singlet QCD corrections to the decay of a Higgs boson into two photons and improve the calculation for the non-singlet case. With the new result presented, the decay width Gamma(H -> \\gamma \\gamma) is completely known at O(G_F \\alpha ^2 \\alpha_s^2, G_F \\alpha ^3).

  14. APPLICATION OF MILLISECOND PULSED LASER WELDING IN MEMS P. Bozorgi*

    E-Print Network [OSTI]

    MacDonald, Noel C.

    APPLICATION OF MILLISECOND PULSED LASER WELDING IN MEMS PACKAGING P. Bozorgi* , C.B. Burgner, Z:YAG pulsed laser is used as a localized heating source to micro-weld a 350 µm titanium cap to the substrate distortion of the welding, several geometries at the cap and substrate interface were investigated

  15. Surface alpha clustering

    SciTech Connect (OSTI)

    Rotter, I.

    1983-05-01

    The problem of alpha decay is discussed on the basis of a theory which describes discrete and continuous states in a unified manner. A formula for numerical calculations is given in which configurational mixing as well as channel coupling is taken into account. The R-matrix approximation is shown to be justified if the width is spread over a small number of decay channels. Generally, renormalization of the wave function is necessary if a factorization of the width is assumed. The importance of channel coupling for the case of a small reduced width is discussed.

  16. 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)

    2012-11-01

    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.

  17. Accreting X-ray millisecond pulsars observed with INTEGRAL

    E-Print Network [OSTI]

    Maurizio Falanga

    2007-11-07

    I review the properties of three X-ray accreting millisecond pulsars observed with INTEGRAL. Out of seven recently discovered accretion-powered pulsars (one discovered by INTEGRAL), three were observed with the INTEGRAL satellite up to 300 keV. Detailed timing and spectral results will be presented, including data obtained during the most recent outburst of the pulsar HETE J1900.1-2455. Accreting X-ray millisecond pulsars are key systems to understand the spin and accretion history of neutron stars. They are also a good laboratory in which to study the source spectra, pulse profile, and phase shift between X-ray pulses in different energy ranges which give additional information of the X-ray production processes and emission environment.

  18. 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)

    Stracka, Simone; /Milan U. /SLAC

    2011-02-07

    In the Standard Model, CP violation in weak interactions involving quarks is parameterized by an irreducible complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing-matrix. The precise determination of the CKM elements is a necessary ingredient for a stringent test of the Standard Model predictions, and is a crucial input for reducing the theoretical error in many New Physics searches with flavor, e.g., in the kaon sector. The unitarity of the CKM matrix is typically expressed as a triangle relationship among its parameters, where the area of the so-called Unitarity Triangle visually depicts the amount of asymmetry between the decays of B particles and their antimatter counterparts. In the past few years, the BABAR and Belle experiments have been able to measure all three angles of the triangle from CP asymmetry measurements. The first asymmetry measurements in B particle decays, about ten years ago, allowed to determine {beta}, which is now known to better than 5% precision. The angles {alpha} and {gamma}, measured in much rarer processes, required several years of data taking before analyses could yield reliable answers. A remarkable feature is that the direct measurement of the angles of the Unitarity Triangle generates an area that is consistent with the area predicted by measurement of the sides. In this thesis we have presented the branching fraction measurements of charged and neutral B meson decays to K{sub 1}(1270){pi} and K{sub 1}(1400){pi}, obtained from a data sample of 454 million {Upsilon}(4S) {yields} B{bar B} events. This analysis is particularly challenging from the experimental side since the branching fractions involved are very low, at the level of 10{sup -6} - 10{sup -7}, and the signal is characterized by the simultaneous presence of two overlapping resonances, which exhibit sizeable interference effects. The combined K{sub 1}(1270){pi} and K{sub 1}(1400){pi} signal is therefore modeled with a K-matrix formalism, which accounts for the effects of interference between the K{sub 1}(1270) and K{sub 1}(1400) mesons by introducing two effective parameters. The model is derived from the analysis, performed by the ACCMOR Collaboration, of the diffractive production of strange mesons.

  19. 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

    2005-12-13

    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.

  20. Millisecond newly born pulsars as efficient accelerators of electrons

    E-Print Network [OSTI]

    Osmanov, Z; Machabeli, G; Chkheidze, N

    2015-01-01

    The newly born millisecond pulsars are investigated as possible energy sources for creating ultra-high energy electrons. The transfer of energy from the star rotation to high energy electrons takes place through the Landau damping of centrifugally driven (via a two stream instability) electrostatic Langmuir waves. Generated in the bulk magnetosphere plasma, such waves grow to high amplitudes, and then damp, very effectively, on relativistic electrons driving them to even higher energies. We show that the rate of transfer of energy is so efficient that no energy losses might affect the mechanism of particle acceleration; the electrons might achieve energies of the order of 10^{18}eV for parameters characteristic of a young star.

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

    E-Print Network [OSTI]

    J. C. Pei; F. R. Xu

    2007-02-01

    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.

  2. Workshop on Precision Measurements of alphas

    E-Print Network [OSTI]

    S. Bethke; A. H. Hoang; S. Kluth; J. Schieck; I. W. Stewart; S. Aoki; M. Beneke; J. Blumlein; N. Brambilla; S. Brodsky; S. Descotes-Genon; J. Erler; S. Forte; T. Gehrmann; C. Glasman; M. Golterman; S. Hashimoto; A. Kronfeld; J. Kuhn; P. Lepage; A. Martin; V. Mateu; S. Menke; Y. Nomura; C. Pahl; F. Petriello; A. Pich; K. Rabbertz; G. Salam; H. Schulz; R. Sommer; M. Steinhauser; B. Webber; CP. Yuan; G. Zanderighi

    2011-10-22

    These are the proceedings of the "Workshop on Precision Measurements of alphas" held at the Max-Planck-Institute for Physics, Munich, February 9-11, 2011. The workshop explored in depth the determination of alphas(mZ) in the MS-bar scheme from the key categories where high precision measurements are currently being made, including DIS and global PDF fits, tau-decays, electroweak 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.

  3. Alpha Radiation

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D S TA I N P A T TSorbentsAllosteric ModulationAlphaBasics

  4. High-energy emission of the first millisecond pulsar

    SciTech Connect (OSTI)

    Ng, C.-Y.; Takata, J.; Leung, G. C. K.; Cheng, K. S. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Philippopoulos, P., E-mail: ncy@bohr.physics.hku.hk [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada)

    2014-06-01

    We report on X-ray and gamma-ray observations of the millisecond pulsar (MSP) B1937+21 taken with the Chandra X-ray Observatory, XMM-Newton, and the Fermi Large Area Telescope. The pulsar X-ray emission shows a purely non-thermal spectrum with a hard photon index of 0.9 ± 0.1, and is nearly 100% pulsed. We found no evidence of varying pulse profile with energy as previously claimed. We also analyzed 5.5 yr of Fermi survey data and obtained much improved constraints on the pulsar's timing and spectral properties in gamma-rays. The pulsed spectrum is adequately fitted by a simple power-law with a photon index of 2.38 ± 0.07. Both the gamma-ray and X-ray pulse profiles show similar two-peak structure and generally align with the radio peaks. We found that the aligned profiles and the hard spectrum in X-rays seem to be common properties among MSPs with high magnetic fields at the light cylinder. We discuss a possible physical scenario that could give rise to these features.

  5. MILLISECOND PULSAR SCINTILLATION STUDIES WITH LOFAR: INITIAL RESULTS

    SciTech Connect (OSTI)

    Archibald, Anne M.; Kondratiev, Vladislav I.; Hessels, Jason W. T.; Stinebring, Daniel R. E-mail: kondratiev@astron.nl E-mail: dan.stinebring@oberlin.edu

    2014-08-01

    High-precision timing of millisecond pulsars (MSPs) over years to decades is a promising technique for direct detection of gravitational waves at nanohertz frequencies. Time-variable, multi-path scattering in the interstellar medium is a significant source of noise for this detector, particularly as timing precision approaches 10 ns or better for MSPs in the pulsar timing array. For many MSPs, the scattering delay above 1 GHz is at the limit of detectability; therefore, we study it at lower frequencies. Using the LOw-Frequency ARray (LOFAR) radio telescope, we have analyzed short (5-20 minutes) observations of 3 MSPs in order to estimate the scattering delay at 110-190 MHz, where the number of scintles is large and, hence, the statistical uncertainty in the scattering delay is small. We used cyclic spectroscopy, still relatively novel in radio astronomy, on baseband-sampled data to achieve unprecedented frequency resolution while retaining adequate pulse-phase resolution. We detected scintillation structure in the spectra of the MSPs PSR B1257+12, PSR J1810+1744, and PSR J2317+1439 with diffractive bandwidths of 6 ± 3, 2.0 ± 0.3, and ?7 kHz, respectively, where the estimate for PSR J2317+1439 is reliable to about a factor of two. For the brightest of the three pulsars, PSR J1810+1744, we found that the diffractive bandwidth has a power-law behavior ??{sub d}??{sup ?}, where ? is the observing frequency and ? = 4.5 ± 0.5, consistent with a Kolmogorov inhomogeneity spectrum. We conclude that this technique holds promise for monitoring the scattering delay of MSPs with LOFAR and other high-sensitivity, low-frequency arrays like the low-frequency component of the Square Kilometre Array.

  6. Scintillation of thin tetraphenyl butadiene films under alpha particle excitation

    E-Print Network [OSTI]

    Pollmann, Tina; Ku?niak, Marcin

    2010-01-01

    The alpha induced scintillation of the wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) was studied to improve the understanding of possible surface alpha backgrounds in the DEAP dark matter search experiment. We found that vacuum deposited thin TPB films emit 882 +/-210 photons per MeV under alpha particle excitation. The scintillation pulse shape consists of a double exponential decay with lifetimes of 11 +/-5 ns and 275 +/-10ns.

  7. 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

    2015-06-11

    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.

  8. 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

    2015-01-01

    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.

  9. 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

    2003-07-01

    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.

  10. Observation of parity violation in the Omega- ---> Lambda K- decay

    SciTech Connect (OSTI)

    Lu, L.C.; /Virginia U.; Burnstein, R.A.; Chakravorty, A.; Chen, Y.C.; Choong, W.-S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Fu, Y.; Gidal, G.; Gustafson, H.R.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, C.M.; Jones, T.D.; Kaplan, D.M.; Longo, M.J.; Luebke, W.; Luk, K.-B.; /Taiwan, Inst. Phys. /UC, Berkeley /Fermilab /Guanajuato U./IIT, Chicago /Lausanne U. /LBL, Berkeley /Michigan U. /South Alabama U. /Virginia U.; ,

    2005-05-01

    The {alpha} decay parameter in the process {Omega}{sup -} {yields} {Lambda}K{sup -} has been measured from a sample of 4.50 million unpolarized {Omega}{sup -} decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 {+-} 0.19(stat) {+-} 0.16(syst)] x 10{sup -2}. This is the first unambiguous evidence for a nonzero {alpha} decay parameter, and hence parity violation, in the {Omega}{sup -} {Lambda}K{sup -} decay.

  11. 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)

    1986-01-01

    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.

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

    E-Print Network [OSTI]

    Preston Jones

    2007-08-31

    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.

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

    E-Print Network [OSTI]

    Kerttu Viironen; Juri Poutanen

    2004-08-13

    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.

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

    E-Print Network [OSTI]

    Viironen, K

    2004-01-01

    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. Fu...

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

    E-Print Network [OSTI]

    Chakraborty, D; Muno, M P; Galloway, D K; Wijnands, R; Van der Klis, M; Markwardt, C B; Chakrabarty, Deepto; Morgan, Edward H.; Muno, Michael P.; Galloway, Duncan K.; Wijnands, Rudy; Klis, Michiel van der; Markwardt, Craig B.

    2003-01-01

    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 distributio...

  16. 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

    2007-05-07

    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.

  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)

    2010-08-15

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

    E-Print Network [OSTI]

    B. Davids

    2008-04-12

    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.

  19. Automatically processed alpha-track radon monitor

    DOE Patents [OSTI]

    Langner, G.H. Jr.

    1993-01-12

    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.

  20. Automatically processed alpha-track radon monitor

    DOE Patents [OSTI]

    Langner, Jr., G. Harold (Mack, CO)

    1993-01-01

    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.

  1. Gravitational Radiation from an Accreting Millisecond Pulsar with a Magnetically Confined Mountain

    E-Print Network [OSTI]

    A. Melatos; D. J. B. Payne

    2005-03-14

    The amplitude of the gravitational radiation from an accreting neutron star undergoing polar magnetic burial is calculated. During accretion, the magnetic field of a neutron star is compressed into a narrow belt at the magnetic equator by material spreading equatorward from the polar cap. In turn, the compressed field confines the accreted material in a polar mountain which is misaligned with the rotation axis in general, producing gravitational waves. The equilibrium hydromagnetic structure of the polar mountain, and its associated mass quadrupole moment, are computed as functions of the accreted mass, M_a, by solving a Grad-Shafranov boundary value problem. The orientation- and polarization-averaged gravitational wave strain, h_c ~ 6e-24 for a 0.6 kHz source at 1 kpc with M_a > 10^-5 M_Sun, exceeds previous estimates that failed to treat equatorward spreading and flux freezing self-consistently. It is concluded that an accreting millisecond pulsar emits a persistent, sinusoidal gravitational wave signal at levels detectable, in principle, by long baseline interferometers after phase-coherent integration, provided that the polar mountain is hydromagnetically stable. Magnetic burial also reduces the magnetic dipole moment, mu, monotonically, implying a novel, observationally testable scaling h_c(mu). The implications for the rotational evolution of (accreting) X-ray and (isolated) radio millisecond pulsars are explored.

  2. AN ASTEROID BELT INTERPRETATION FOR THE TIMING VARIATIONS OF THE MILLISECOND PULSAR B1937+21

    SciTech Connect (OSTI)

    Shannon, R. M.; Cordes, J. M. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States)] [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Metcalfe, T. S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO 80301 (United States)] [Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO 80301 (United States); Lazio, T. J. W. [Jet Propulsion Laboratory, California Institute of Technology, M/S 138-308, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, California Institute of Technology, M/S 138-308, Pasadena, CA 91109 (United States); Cognard, I.; Desvignes, G.; Theureau, G. [LPC2E/CNRS-Universite d'Orleans, Orleans, F-45071, Cedex 2 (France)] [LPC2E/CNRS-Universite d'Orleans, Orleans, F-45071, Cedex 2 (France); Janssen, G. H.; Purver, M. B.; Stappers, B. W. [University of Manchester and Jodrell Bank Observatory, Manchester, M13 9PL (United Kingdom)] [University of Manchester and Jodrell Bank Observatory, Manchester, M13 9PL (United Kingdom); Jessner, A.; Kramer, M.; Lazaridis, K., E-mail: ryan.shannon@csiro.au, E-mail: cordes@astro.cornell.edu [Max-Planck-Institut fuer Radioastonomie, Bonn, D-53121 (Germany)

    2013-03-20

    Pulsar timing observations have revealed companions to neutron stars that include other neutron stars, white dwarfs, main-sequence stars, and planets. We demonstrate that the correlated and apparently stochastic residual times of arrival from the millisecond pulsar B1937+21 are consistent with the signature of an asteroid belt having a total mass {approx}< 0.05 M{sub Circled-Plus }. Unlike the solar system's asteroid belt, the best fit pulsar asteroid belt extends over a wide range of radii, consistent with the absence of any shepherding companions. We suggest that any pulsar that has undergone accretion-driven spin-up and subsequently evaporated its companion may harbor orbiting asteroid mass objects. The resulting timing variations may fundamentally limit the timing precision of some of the other millisecond pulsars. Observational tests of the asteroid belt model include identifying periodicities from individual asteroids, which are difficult; testing for statistical stationarity, which becomes possible when observations are conducted over a longer observing span; and searching for reflected radio emission.

  3. Alpha Particle Diagnostic

    SciTech Connect (OSTI)

    Fisher, Ray, K.

    2009-05-13

    The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

  4. 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

    2008-04-16

    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.

  5. DISCOVERY OF AN ACCRETING MILLISECOND PULSAR IN THE ECLIPSING BINARY SYSTEM SWIFT J1749.4–2807

    E-Print Network [OSTI]

    Altamirano, D.

    We report on the discovery and the timing analysis of the first eclipsing accretion-powered millisecond X-ray pulsar (AMXP): SWIFT J1749.4-2807. The neutron star rotates at a frequency of ~517.9 Hz and is in a binary system ...

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

    E-Print Network [OSTI]

    Papitto, A

    2015-01-01

    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 ...

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

    E-Print Network [OSTI]

    Lee, Umin

    2014-01-01

    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 $\

  8. NuSTAR OBSERVATIONS OF THE STATE TRANSITION OF MILLISECOND PULSAR BINARY PSR J1023+0038

    E-Print Network [OSTI]

    Chakrabarty, Deepto

    We report NuSTAR observations of the millisecond pulsar-low-mass X-ray binary (LMXB) transition system PSR J1023+0038 from 2013 June and October, before and after the formation of an accretion disk around the neutron star. ...

  9. MILLISECOND PULSAR AGES: IMPLICATIONS OF BINARY EVOLUTION AND A MAXIMUM SPIN LIMIT

    SciTech Connect (OSTI)

    Kiziltan, Buelent; Thorsett, Stephen E., E-mail: bulent@astro.ucsc.ed [Department of Astronomy and Astrophysics, University of California and UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)

    2010-05-20

    In the absence of constraints from the binary companion or supernova remnant, the standard method for estimating pulsar ages is to infer an age from the rate of spin-down. While the generic spin-down age may give realistic estimates for normal pulsars, it can fail for pulsars with very short periods. Details of the spin-up process during the low-mass X-ray binary (LMXB) phase pose additional constraints on the period (P) and spin-down rates ( P-dot ) that may consequently affect the age estimate. Here, we propose a new recipe to estimate millisecond pulsar (MSP) ages that parametrically incorporates constraints arising from binary evolution and limiting physics. We show that the standard method can be improved by this approach to achieve age estimates closer to the true age while the standard spin-down age may overestimate or underestimate the age of the pulsar by more than a factor of {approx}10 in the millisecond regime. We use this approach to analyze the population on a broader scale. For instance, in order to understand the dominant energy loss mechanism after the onset of radio emission, we test for a range of plausible braking indices. We find that a braking index of n = 3 is consistent with the observed MSP population. We demonstrate the existence and quantify the potential contributions of two main sources of age corruption: the previously known 'age bias' due to secular acceleration and 'age contamination' driven by sub-Eddington progenitor accretion rates. We explicitly show that descendants of LMXBs that have accreted at very low rates ( m-dot << M-dot{sub Edd}) will exhibit ages that appear older than the age of the Galaxy. We further elaborate on this technique, the implications and potential solutions it offers regarding MSP evolution, the underlying age distribution, and the post-accretion energy loss mechanism.

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

    E-Print Network [OSTI]

    Hummel, John Philip

    2010-01-01

    included in this study. of nuclides. Those for the even -for that class of nuclides. II. EXPERIMENTAL TECHNIQUES Thein this particular nuclide stems from several points: (a)

  11. Half-lives of $?$ decay from natural nuclides and from superheavy elements

    E-Print Network [OSTI]

    Yibin Qian; Zhongzhou Ren

    2014-10-10

    Recently, experimental researches on the $\\alpha$ decay with long lifetime are one of hot topics in the contemporary nuclear physics [e.g. N. Kinoshita {\\sl et al.} (2012) and J. W. Beeman {\\sl et al.} (2012) ]. In this study, we have systematically investigated the extremely long-lived $\\alpha$-decaying nuclei within a generalized density-dependent cluster model involving the experimental nuclear charge radii. In detail, the important density distribution of daughter nuclei is deduced from the corresponding experimental charge radii, leading to an improved $\\alpha$-core potential in the quantum tunneling calculation of $\\alpha$-decay width. Besides the excellent agreement between theory and experiment, predictions on half-lives of possible candidates for natural $\\alpha$ emitters are made for future experimental detections. In addition, the recently confirmed $\\alpha$-decay chain from $^{294}$117 is well described, including the attractive long-lived $\\alpha$-decaying $^{270}$Db, i.e., a positive step towards the "island of stability" in the superheavy mass region.

  12. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect (OSTI)

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

    2012-04-04

    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.

  13. 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

    2015-06-12

    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.

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

    E-Print Network [OSTI]

    D. J. B. Payne; A. Melatos

    2006-07-11

    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.

  15. Properties and Evolution of the Redback Millisecond Pulsar Binary PSR J2129-0429

    E-Print Network [OSTI]

    Bellm, Eric C; Breton, Rene P; Phinney, E Sterl; Bhalerao, Varun B; Camilo, Fernando; Dahal, Sumit; Djorgovski, S G; Drake, Andrew J; Hessels, J W T; Laher, Russ R; Levitan, David B; Lewis, Fraser; Mahabal, Ashish A; Ofek, Eran O; Prince, Thomas A; Ransom, Scott M; Roberts, Mallory S E; Russell, David M; Sesar, Branimir; Surace, Jason A; Tang, Sumin

    2015-01-01

    PSR J2129-0429 is a "redback" eclipsing millisecond pulsar binary with an unusually long 15.2 hour orbit. It was discovered by the Green Bank Telescope in a targeted search of unidentified Fermi gamma-ray sources. The pulsar companion is optically bright (mean $m_R = 16.6$ mag), allowing us to construct the longest baseline photometric dataset available for such a system. We present ten years of archival and new photometry of the companion from LINEAR, CRTS, PTF, the Palomar 60-inch, and LCOGT. Radial velocity spectroscopy using the Double-Beam Spectrograph on the Palomar 200-inch indicates that the pulsar is massive: $1.74\\pm0.18 M_\\odot$. The G-type pulsar companion has mass $0.44\\pm0.04 M_\\odot$, one of the heaviest known redback companions. It is currently 95\\% Roche-lobe filling and only mildly irradiated by the pulsar. We identify a clear 13.1 mmag yr$^{-1}$ secular decline in the mean magnitude of the companion as well as smaller-scale variations in the optical lightcurve shape. This behavior may indic...

  16. Optical Identification of He White Dwarfs Orbiting Four Millisecond Pulsars in the Globular Cluster 47 Tucanae

    E-Print Network [OSTI]

    Cadelano, M; Ferraro, F R; Salaris, M; Dalessandro, E; Lanzoni, B; Freire, P C C

    2015-01-01

    We used ultra-deep UV observations obtained with the Hubble Space Telescope to search for optical companions to binary millisecond pulsars (MSPs) in the globular cluster 47 Tucanae. We identified four new counterparts (to MSPs 47TucQ, 47TucS, 47TucT and 47TucY) and confirmed those already known (to MSPs 47TucU and 47TucW). In the color magnitude diagram, the detected companions are located in a region between the main sequence and the CO white dwarf cooling sequences, consistent with the cooling tracks of He white dwarfs of mass between 0.15 Msun and 0.20 Msun. For each identified companion, mass, cooling age, temperature and pulsar mass (as a function of the inclination angle) have been derived and discussed. For 47TucU we also found that the past accretion history likely proceeded in a sub-Eddington rate. The companion to the redback 47TucW is confirmed to be a non degenerate star, with properties particularly similar to those observed for black widow systems. Two stars have been identified within the 2-sig...

  17. Timing analysis for 20 millisecond pulsars in the Parkes Pulsar Timing Array

    E-Print Network [OSTI]

    Reardon, D J; Coles, W; Levin, Y; Keith, M J; Bailes, M; Bhat, N D R; Burke-Spolaor, S; Dai, S; Kerr, M; Lasky, P D; Manchester, R N; Os?owski, S; Ravi, V; Shannon, R M; van Straten, W; Toomey, L; Wang, J; Wen, L; You, X P; Zhu, X -J

    2015-01-01

    We present timing models for 20 millisecond pulsars in the Parkes Pulsar Timing Array. The precision of the parameter measurements in these models has been improved over earlier results by using longer data sets and modelling the non-stationary noise. We describe a new noise modelling procedure and demonstrate its effectiveness using simulated data. Our methodology includes the addition of annual dispersion measure (DM) variations to the timing models of some pulsars. We present the first significant parallax measurements for PSRs J1024-0719, J1045-4509, J1600-3053, J1603-7202, and J1730-2304, as well as the first significant measurements of some post-Keplerian orbital parameters in six binary pulsars, caused by kinematic effects. Improved Shapiro delay measurements have resulted in much improved pulsar mass measurements, particularly for PSRs J0437-4715 and J1909-3744 with $M_p=1.44\\pm0.07$ $M_\\odot$ and $M_p=1.47\\pm0.03$ $M_\\odot$ respectively. The improved orbital period-derivative measurement for PSR J043...

  18. Magnetic field structure and torque in accretion discs around millisecond pulsars

    E-Print Network [OSTI]

    Naso, L; Miller, J C

    2013-01-01

    Millisecond pulsars are rather weakly-magnetized neutron stars which are thought to have been spun up by disc accretion, with magnetic linkage between the star and the disc playing a key role. Their spin history depends sensitively on details of the magnetic field structure, but idealized models from the 1980s and 1990s are still commonly used for calculating the magnetic field components. This paper is the third in a series presenting results from a step-by-step analysis which we are making of the problem, starting with very simple models and then progressively including additional features one at a time, with the aim of gaining new insights into the mechanisms involved. In our first two papers, the magnetic field structure in the disc was calculated for a standard Shakura and Sunyaev model, by solving the magnetic induction equation numerically in the stationary limit within the kinematic approximation; here we consider a more general velocity field in the disc, including backflow. We find that the profiles...

  19. The binary millisecond pulsar PSR J1023+0038 during its accretion state - I. Optical variability

    E-Print Network [OSTI]

    Shahbaz, T; Nevado, S P; Rodríguez-Gil, P; Casares, J; Dhillon, V S; Marsh, T R; Littlefair, S; Leckngam, A; Poshyachinda, S

    2015-01-01

    We present time-resolved optical photometry of the binary millisecond `redback' pulsar PSR J1023+0038 (=AY Sex) during its low-mass X-ray binary phase. The light curves taken between 2014 January and April show an underlying sinusoidal modulation due to the irradiated secondary star and accretion disc. We also observe superimposed rapid flaring on time-scales as short as ~20 s with amplitudes of ~0.1-0.5 mag and additional large flare events on time-scales of ~5-60 min with amplitudes ~0.5-1.0 mag. The power density spectrum of the optical flare light curves is dominated by a red-noise component, typical of aperiodic activity in X-ray binaries. Simultaneous X-ray and UV observations by the Swift satellite reveal strong correlations that are consistent with X-ray reprocessing of the UV light, most likely in the outer regions of the accretion disc. On some nights we also observe sharp-edged, rectangular, flat-bottomed dips randomly distributed in orbital phase, with a median duration of ~250 s and a median ingr...

  20. Decay estimates for the one-dimensional wave equation with an inverse power potential

    E-Print Network [OSTI]

    Roland Donninger; Wilhelm Schlag

    2010-03-10

    We study the wave equation on the real line with a potential that falls off like $|x|^{-\\alpha}$ for $|x| \\to \\infty$ where $2 < \\alpha \\leq 4$. We prove that the solution decays pointwise like $t^{-\\alpha}$ as $t \\to \\infty$ provided that there are no resonances at zero energy and no bound states. As an application we consider the $\\ell=0$ Price Law for Schwarzschild black holes. This paper is part of our investigations into decay of linear waves on a Schwarzschild background.

  1. HIGH-FIDELITY RADIO ASTRONOMICAL POLARIMETRY USING A MILLISECOND PULSAR AS A POLARIZED REFERENCE SOURCE

    SciTech Connect (OSTI)

    Van Straten, W.

    2013-01-15

    A new method of polarimetric calibration is presented in which the instrumental response is derived from regular observations of PSR J0437-4715 based on the assumption that the mean polarized emission from this millisecond pulsar remains constant over time. The technique is applicable to any experiment in which high-fidelity polarimetry is required over long timescales; it is demonstrated by calibrating 7.2 years of high-precision timing observations of PSR J1022+1001 made at the Parkes Observatory. Application of the new technique followed by arrival time estimation using matrix template matching yields post-fit residuals with an uncertainty-weighted standard deviation of 880 ns, two times smaller than that of arrival time residuals obtained via conventional methods of calibration and arrival time estimation. The precision achieved by this experiment yields the first significant measurements of the secular variation of the projected semimajor axis, the precession of periastron, and the Shapiro delay; it also places PSR J1022+1001 among the 10 best pulsars regularly observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is shown that the timing accuracy of a large fraction of the pulsars in the PPTA is currently limited by the systematic timing error due to instrumental polarization artifacts. More importantly, long-term variations of systematic error are correlated between different pulsars, which adversely affects the primary objectives of any pulsar timing array experiment. These limitations may be overcome by adopting the techniques presented in this work, which relax the demand for instrumental polarization purity and thereby have the potential to reduce the development cost of next-generation telescopes such as the Square Kilometre Array.

  2. 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)

    2009-12-10

    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.

  3. Does the alpha cluster structure in light nuclei persist through the fusion process?

    E-Print Network [OSTI]

    J. Vadas; T. K. Steinbach; J. Schmidt; Varinderjit Singh; C. Haycraft; S. Hudan; R. T. deSouza; L. T. Baby; S. A. Kuvin; I. Wiedenhover

    2015-08-31

    [Background] Despite the importance of light-ion fusion in nucleosynthesis, a limited amount of data exists regarding the de-excitation following fusion for such systems. [Purpose] To explore the characteristics of alpha emission associated with the decay of light fused systems at low excitation energy. [Method] Alpha particles were detected in coincidence with evaporation residues (ER) formed by the fusion of 18O and 12C nuclei. Both alpha particles and ERs were identified on the basis of their energy and time-of-flight. ERs were characterized by their energy spectra and angular distributions while the alpha particles were characterized by their energy spectra, angular distributions, and cross-sections. [Results] While the energy spectra and angular distributions for the alpha particles are well reproduced by statistical model codes, the measured cross-section is substantially underpredicted by the models. Comparison with similar systems reveals that the fundamental quantity for the alpha cross-section is Ec.m. and not the excitation energy of the fused system. [Conclusion]The enhancement in the measured alpha cross-section as compared to the statistical model codes and its dependence with Ec.m. suggest that a coupling between pre-existing alpha cluster structure and the collision dynamics is responsible for the observed alpha cross-section.

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

    E-Print Network [OSTI]

    Satoshi Mishima

    2007-03-18

    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.

  5. Baryon helicity in B decay

    SciTech Connect (OSTI)

    Suzuki, Mahiko

    2005-05-13

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

  6. 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

    2007-07-10

    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.

  7. 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

    2004-10-11

    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).

  8. 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

    2000-11-19

    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.

  9. Radio Pulse Properties of the Millisecond Pulsar PSR J0437-4715. I. Observations at 20cm

    E-Print Network [OSTI]

    F. A. Jenet; S. B. Anderson; V. M. Kaspi; T. A. Prince; S. C. Unwin

    1998-03-03

    We present a total of 48 minutes of observations of the nearby, bright millisecond pulsar PSR J0437-4715 taken at the Parkes radio observatory in Australia. The data were obtained at a central radio frequency of 1380 MHz using a high-speed tape recorder that permitted coherent Nyquist sampling of 50 MHz of bandwidth in each of two polarizations. Using the high time resolution available from this voltage recording technique, we have studied a variety of single-pulse properties, most for the first time in a millisecond pulsar. We find no evidence for "diffractive" quantization effects in the individual pulse arrival times or amplitudes as have been reported for this pulsar at lower radio frequency using coarser time resolution (Ables et al. 1997). Overall, we find that the single pulse properties of PSR J0437-4715 are similar to those of the common slow-rotating pulsars, even though this pulsar's magnetosphere and surface magnetic field are several orders of magnitude smaller than those of the general population. The pulsar radio emission mechanism must therefore be insensitive to these fundamental neutron star properties.

  10. Probable new type of reaction mechanism: Double. cap alpha. direct transfer process

    SciTech Connect (OSTI)

    Xu Shu-wei; Wu Guo-hua; Miao Rong-zhi; Han Fei

    1983-10-01

    It is assumed that /sup 8/Be consists of two ..cap alpha.. particles which are close to each other in configuration space. A spectroscopic density of /sup 8/Be cluster in the residue nuclei is then obtained, which is proportional to the square of the preformation probability of ..cap alpha.. particle at nuclear surface. Using the improved method of parametrization of EFR-DWBA overlap integral,/sup 1//sup en-dash//sup 2/ we calculate the double differential energy spectra and angular distributions of ..cap alpha.. particles for the reactions /sup 209/Bi (/sup 12/C, ..cap alpha..) /sup 217/Fr and extract the preformation probability of ..cap alpha.. particle at the surface of /sup 217/Fr nuclei from fitting the experimental data. The agreement within the range of calculation error between the preformation probabilities extracted from transfer reactions and ..cap alpha.. decay suggests that the reaction /sup 209/Bi(/sup 12/C, ..cap alpha..) /sup 217/Fr may be explained as a double ..cap alpha.. direct transfer process.

  11. Oxidative dehydrogenation of ethane at millisecond contact times: Effect of H{sub 2} addition

    SciTech Connect (OSTI)

    Bodke, A.S.; Henning, D.; Schmidt, L.D.; Bharadwaj, S.S.; Maj, J.J.; Siddall, J.

    2000-04-01

    The oxidative dehydrogenation of ethane using Pt/{alpha}-Al{sub 2}O{sub 3} and various bimetallic catalysts operating at {approximately}1,000 C and very short contact times is examined with H{sub 2} addition to the feed. When H{sub 2} is added with a Pt catalyst, the ethylene selectivity rises from 65 to 72% but ethane conversion drops from 70 to 52%. However, using a Pt-Sn/{alpha}-Al{sub 2}O{sub 3} catalyst, the C{sub 2}H{sub 4} selectivity increases from 70 to greater than 85%, while the conversion remains {approximately}70%. The process also produces approximately as much H{sub 2} as is added to the feed. Effects of other metal promoters, sphere bed and fibermat supports, preheat, pressure, nitrogen dilution, and flow rate are examined in an effort to further elucidate the mechanism. Deactivation of the Pt-Sn catalyst is examined, and a simple method of regenerating the activity on-line is demonstrated. Possible mechanisms to explain high selectivities to ethylene are discussed. Although the process can be regarded as a simple two-step reaction sequence with the exothermic oxidation of hydrogen or ethane driving the endothermic dehydrogenation of ethane to ethylene, the exact contributions of heterogeneous or gas-phase reactions and their spatial variations within the catalyst are yet to be determined.

  12. Attempt to extract the preformation probability of. cap alpha. cluster at the surface of heavy nuclei by means of. cap alpha. -transfer reactions leading to the continuum states

    SciTech Connect (OSTI)

    Xu Shu-wei; Wu Guo-hua; Miao Rong-zhi; Han Fei

    1983-07-01

    The method of parametrization of an EFR-DWBA overlap integral developed by T. Udagawa and T. Tamura et al./sup 1/ is improved. Using the improved method we have fitted the experimental double differential energy spectrum of the /sup 8/Be cluster coming from the reaction /sup 208/Pb(/sup 12/C, /sup 8/Be) /sup 212/Po leading to the continuum states and extracted the preformation probability of the ..cap alpha.. cluster at the surface of the /sup 212/Po nucleus. Within the range of calculation error, the result is in agreement with that extracted from fitting the experimental data of ..cap alpha.. decay.

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

    E-Print Network [OSTI]

    Yu, Peter K.N.

    sterilisation. For alpha-particle radiobiological experiments, it is easier to quantify the alpha energies

  14. 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.

    1999-09-01

    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.

  15. Protein Conformational Relaxation and Ligand Migration in Myoglobin: A Nanosecond to Millisecond Molecular Movie from Time-Resolved Laue X-ray

    E-Print Network [OSTI]

    Moffat, Keith

    Protein Conformational Relaxation and Ligand Migration in Myoglobin: A Nanosecond to Millisecond and ligand migration at room temperature following photolysis of a single crystal of carbon monoxy- myoglobin and at the Xe 1 binding site in the proximal pocket. The population by CO of the primary, distal site peaks

  16. Quantum mechanical calculation of Rydberg-Rydberg Auger decay rates

    E-Print Network [OSTI]

    Kiffner, Martin; Li, Wenhui; Jaksch, Dieter

    2015-01-01

    We present quantum mechanical calculations of the Auger decay rate $\\Gamma_A$ of two Rubidium Rydberg atoms with weakly overlapping electron clouds. The two-electron wavefunction is modelled by a single Slater determinant of $nd$ Rydberg orbitals with principal quantum number $n\\le35$. The dependence of $\\Gamma_A$ on the atom-atom separation $R$ is well described by a power law $\\Gamma_A \\propto R^{\\alpha}$ and we calculate the exponents $\\alpha$ for various initial states. For atomic separations equal to the size of the Rydberg electron wave function $R_n$ we find that $\\Gamma_A \\propto n^{-5}$. We discuss the importance of Auger decay compared to other contributions to the electron dynamics in the two Rydberg atom system.

  17. Rare Hadronic B Decays

    SciTech Connect (OSTI)

    Bevan, A.J.

    2006-06-07

    Rare hadronic B-meson decays allow us to study CP violation. The class of B-decays final states containing two vector mesons provides a rich set of angular correlation observables to study. This article reviews some of the recent experimental results from the BABAR and Belle collaborations.

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

    E-Print Network [OSTI]

    Sergei P. Maydanyuk; Peng-Ming Zhang; Li-Ping Zou

    2015-05-04

    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 nucleon structure: (a) direction to nuclei with smaller $Z$, (b) direction to nuclei with larger $Q_{\\alpha}$-values.

  19. The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational wave searches

    E-Print Network [OSTI]

    Caballero, R N; Lentati, L; Desvignes, G; Champion, D J; Verbiest, J P W; Janssen, G H; Stappers, B W; Kramer, M; Lazarus, P; Possenti, A; Tiburzi, C; Perrodin, D; Os?owski, S; Babak, S; Bassa, C G; Brem, P; Burgay, M; Cognard, I; Gair, J R; Graikou, E; Guillemot, L; Hessels, J W T; Karuppusamy, R; Lassus, A; Liu, K; McKee, J; Mingarelli, C M F; Petiteau, A; Purver, M B; Rosado, P A; Sanidas, S; Sesana, A; Shaifullah, G; Smits, R; Taylor, S R; Theureau, G; van Haasteren, R; Vecchio, A

    2015-01-01

    The sensitivity of Pulsar Timing Arrays to gravitational waves depends critically on the noise present in the individual pulsar timing data. Noise may be either intrinsic or extrinsic to the pulsar. Intrinsic sources of noise might come from rotational instabilities, for example. Extrinsic sources of noise include contributions from physical processes which are not sufficiently well modelled, for example, dispersion and scattering effects, analysis errors and instrumental instabilities. We present the results from a noise analysis for 42 millisecond pulsars (MSPs) observed with the European Pulsar Timing Array. For characterising the low-frequency, stochastic and achromatic noise component, or "timing noise", we employ two methods, based on Bayesian and frequentist statistics. For 25 MSPs, we achieve statistically significant measurements of their timing noise parameters and find that the two methods give consistent results. For the remaining 17 MSPs, we place upper limits on the timing noise amplitude at the...

  20. 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

    2010-06-30

    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.

  1. Measurement of the cross section of charmed hadrons and the nuclear dependence alpha

    SciTech Connect (OSTI)

    Blanco-Covarrubias, E.Alejandro; /San Luis Potosi U.

    2009-12-01

    With data from the SELEX experiment we study charm hadro-production. We report the differential production cross sections as function of the longitudinal and transverse momentum, as well as for two different target materials, of 14 charmed hadron and/or their decay modes. This is the most extensive study to date. SELEX is a fixed target experiment at Fermilab with high forward acceptance; it took data during 1996-1997 with 600 GeV/c {Sigma}{sup -} and {pi}{sup -}, and 540 GeV/c proton and {pi}{sup +} beams. It used 5 target foils (two copper and three diamond). We use the results to determine {alpha}, used in parametrizing the production cross section as {infinity} A{sup {alpha}}, where A is the mass number of the target nuclei. We found within our statistics that {alpha} is independent of the longitudinal momentum fraction x{sub F} in the interval 0.1 < x{sub F} < 1.0, with {alpha} = 0.778 {+-} 0.014. The average value of {alpha} for charm production by pion beams is {alpha}{sub meson} = 0.850 {+-} 0.028. This is somewhat larger than the corresponding average {alpha}{sub baryon} = 0.755 {+-} 0.016 for charm production by baryon beams ({Sigma}{sup -} and protons).

  2. Charged-Particle Decay from Giant Monopole Resonance in Si-28 

    E-Print Network [OSTI]

    Toba, Y.; Lui, YW; Youngblood, David H.; Garg, U.; Grabmayr, P.; Knopfle, K. T.; Riedesel, H.; Wagner, G. J.

    1990-01-01

    resonance region of "Si excited with a 129 MeV alpha particle beam has been measured in coincidence with inelastic alpha particles detected at O'. The angular correlation data show the presence of decay from both EO and E2 giant resonances. The EO giant... and alpha particles with en- ergies between 100 and 170 MeV. To identify the mono- pole, the experiments were performed at small angles, in- cluding 0' where the monopole is excited most strongly. In medium and heavy nuclei (mass number A ) 64), the GMR...

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

    E-Print Network [OSTI]

    Shinichi Kotani; Fumihiko Nakano

    2014-12-29

    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.

  4. Modulated curvaton decay

    SciTech Connect (OSTI)

    Assadullahi, Hooshyar; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Firouzjahi, Hassan [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Namjoo, Mohammad Hossein, E-mail: hooshyar.assadullahi@port.ac.uk, E-mail: firouz@mail.ipm.ir, E-mail: mh.namjoo@mail.ipm.ir, E-mail: david.wands@port.ac.uk [Yukawa Institute for theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2013-03-01

    We study primordial density perturbations generated by the late decay of a curvaton field whose decay rate may be modulated by the local value of another isocurvature field, analogous to models of modulated reheating at the end of inflation. We calculate the primordial density perturbation and its local-type non-Gaussianity using the sudden-decay approximation for the curvaton field, recovering standard curvaton and modulated reheating results as limiting cases. We verify the Suyama-Yamaguchi inequality between bispectrum and trispectrum parameters for the primordial density field generated by multiple field fluctuations, and find conditions for the bound to be saturated.

  5. 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.)

    2002-01-01

    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.

  6. Design and performance of an ionisation chamber for the measurement of low alpha-activities

    E-Print Network [OSTI]

    Andreas Hartmann; Jochen Hutsch; Felix Krüger; Manfred Sobiella; Heinrich Wilsenach; Kai Zuber

    2015-11-04

    A new ionisation chamber for alpha-spectroscopy has been built from radio-pure materials for the purpose of investigating long lived alpha-decays. The measurement makes use of pulse shape analysis to discriminate between signal and background events. The design and performance of the chamber is described in this paper. A background rate of ($10.9 \\pm 0.6$) counts per day in the energy region of 1 MeV to 9 MeV was achieved with a run period of 30.8 days. The background is dominantly produced by radon daughters.

  7. Alpha Gamma Hot Cell Facility

    E-Print Network [OSTI]

    Kemner, Ken

    . These operations can result in elevated radiological risks to the facility and workers. ARG-US -- meaning and should be developed for and deployed in nuclear and radiological facilities to aid operation and reduceAlpha Gamma Hot Cell Facility Argonne National Laboratory is a U.S. Department of Energy laboratory

  8. Neutrinoless double beta decay

    E-Print Network [OSTI]

    K. Zuber

    2012-01-23

    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.

  9. Double Beta Decay

    E-Print Network [OSTI]

    Steven R. Elliott; Petr Vogel

    2002-02-27

    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.

  10. 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

    2007-03-21

    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.

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

    E-Print Network [OSTI]

    Z. Y. Wang; Z. M. Niu; Q. Liu; J. Y. Guo

    2015-03-05

    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) model, the rms deviation of $\\alpha$-decay half-lives with respect to the known data falls to $0.697$.

  12. Gravitational-wave spin-down and stalling lower limits on the electrical resistivity of the accreted mountain in a millisecond pulsar

    E-Print Network [OSTI]

    Matthias Vigelius; Andrew Melatos

    2010-05-13

    The electrical resistivity of the accreted mountain in a millisecond pulsar is limited by the observed spin-down rate of binary radio millisecond pulsars (BRMSPs) and the spins and X-ray fluxes of accreting millisecond pulsars (AMSPs). We find $\\eta \\ge 10^{-28}\\,\\mathrm{s}\\, (\\tau_\\mathrm{SD}/1\\,\\mathrm{Gyr})^{-0.8}$ (where $\\tau_\\mathrm{SD}$ is the spin-down age) for BRMSPs and $\\eta \\ge 10^{-25}\\,\\mathrm{s}\\,(\\dot{M}_\\mathrm{a}/\\dot{M}_\\mathrm{E})^{0.6}$ (where $\\dot{M}_\\mathrm{a}$ and $\\dot{M}_\\mathrm{E}$ are the actual and Eddington accretion rates) for AMSPs. These limits are inferred assuming that the mountain attains a steady state, where matter diffuses resistively across magnetic flux surfaces but is replenished at an equal rate by infalling material. The mountain then relaxes further resistively after accretion ceases. The BRMSP spin-down limit approaches the theoretical electron-impurity resistivity at temperatures $\\ga 10^5$ K for an impurity concentration of $\\sim 0.1$, while the AMSP stalling limit falls two orders of magnitude below the theoretical electron-phonon resistivity for temperatures above $10^8$ K. Hence BRMSP observations are already challenging theoretical resistivity calculations in a useful way. Next-generation gravitational-wave interferometers will constrain $\\eta$ at a level that will be competitive with electromagnetic observations.

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

    E-Print Network [OSTI]

    Bednarek, W

    2015-01-01

    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...

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

    SciTech Connect (OSTI)

    Kerr, M.; Camilo, F.; Johnson, T. J.; Ferrara, E. C.; Harding, A. K.; Guillemot, L.; Kramer, M.; Hessels, J.; Johnston, S.; Keith, M.; Reynolds, J. E.; Ransom, S. M.; Ray, P. S.; Wood, K. S.; Sarkissian, J. E-mail: fernando@astro.columbia.edu

    2012-03-20

    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.

  15. EXPLORING THE X-RAY AND ?-RAY PROPERTIES OF THE REDBACK MILLISECOND PULSAR PSR J1723–2837

    SciTech Connect (OSTI)

    Hui, C. Y.; Tam, P. H. T.; Kong, A. K. H.; Wu, J. H. K.; Takata, J.; Cheng, K. S.; Wu, E. M. H.; Lin, L. C. C.

    2014-01-20

    We have investigated the X-ray and ?-ray properties of the redback millisecond pulsar PSR J1723–2837 with XMM-Newton, Chandra, and Fermi. We have discovered the X-ray orbital modulation of this binary system with a minimum that coincides with the phases of radio eclipse. The X-ray emission is clearly non-thermal in nature, which can be described well by a simple power law with a photon index of ?1.2. The phase-averaged luminosity is ?9 × 10{sup 31} erg s{sup –1} in 0.3-10 keV, which consumes ?0.2% of the spin-down power. We have detected the ?-ray emission in 0.1-300 GeV from this system at a significance of ?6? for the first time. The ?-rays in this energy range consume ?2% of the spin-down power and can be modeled by a power law with a photon index of ?2.6. We discuss the high energy properties of the new redback in the context of an intrabinary shock model.

  16. 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

    2015-02-09

    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.

  17. 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)

    2012-02-20

    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}.

  18. Constraints on neutrino decay lifetime using long-baseline charged and neutral current data

    E-Print Network [OSTI]

    R. A. Gomes; A. L. G. Gomes; O. L. G. Peres

    2014-12-11

    We investigate the status of a scenario involving oscillations and decay for charged and neutral current data from the MINOS and T2K experiments. We first present an analysis of charged current neutrino and anti-neutrino data from MINOS in the framework of oscillation with decay and obtain a best fit for non-zero decay parameter $\\alpha_3$. The MINOS charged and neutral current data analysis results in the best fit for $|\\Delta m_{32}^2| = 2.34\\times 10^{-3}$~eV$^2$, $\\sin^2 \\theta_{23} = 0.60$ and zero decay parameter, which corresponds to the limit for standard oscillations. Our combined MINOS and T2K analysis reports a constraint at the 90\\% confidence level for the neutrino decay lifetime $\\tau_3/m_3 > 2.8 \\times 10^{-12}$~s/eV. This is the best limit based only on accelerator produced neutrinos.

  19. Suppressed Charmed B Decay

    SciTech Connect (OSTI)

    Snoek, Hella Leonie; /Vrije U., Amsterdam

    2011-11-28

    This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle {gamma}, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle {gamma} can be performed using the decays of neutral B mesons. The B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay is sensitive to the angle {gamma} and, in comparison to the current decays that are being employed, could significantly enhance the measurement of this angle. However, the low expected branching fraction for the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay channels could severely impact the measurement. A prerequisite of the measurement of the CKM angle is the observation of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay on which this thesis reports. The BABAR experiment consists of the BABAR detector and the PEP-II e{sup +}e{sup -} collider. The design of the experiment has been optimized for the study of CP violation in the decays of neutral B mesons but is also highly suitable for the search for rare B decays such as the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay. The PEP-II collider operates at the {Upsilon}(4S) resonance and is a clean source of B{bar B} meson pairs.

  20. Excited Upsilon Radiative Decays

    E-Print Network [OSTI]

    Randy Lewis; R. M. Woloshyn

    2011-11-13

    Bottomonium S-wave states were studied using lattice NRQCD. Masses of ground and excited states were calculated using multiexponential fitting to a set of correlation functions constructed using both local and wavefunction-smeared operators. Three-point functions for M1 transitions between vector and pseudoscalar states were computed. Robust signals for transitions involving the first two excited states were obtained. The qualitative features of the transition matrix elements are in agreement with expectations. The calculated values of matrix elements for Y(2S) and Y(3S) decay are considerably larger than values inferred from measured decay widths.

  1. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D S TA I N P A T TSorbentsAllosteric Modulation ofOeffect

  2. WHY SEARCH FOR DOUBLE BETA DECAY?

    E-Print Network [OSTI]

    Kayser, B.

    2010-01-01

    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

  3. Attention decay in science

    E-Print Network [OSTI]

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  4. Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Heinrich Päs; Werner Rodejohann

    2015-07-01

    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.

  5. Neutrinoless double beta decay

    E-Print Network [OSTI]

    Petr Vogel

    2006-11-17

    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\

  6. Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Päs, Heinrich

    2015-01-01

    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.

  7. Vacuum Energy Decay

    E-Print Network [OSTI]

    Enrique Álvarez; Roberto Vidal

    2011-11-09

    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, $\\l$.

  8. Local Varying-Alpha Theories

    E-Print Network [OSTI]

    John D. Barrow; Joao Magueijo

    2015-01-30

    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.

  9. 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)

    2014-04-10

    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.

  10. VERY LONG BASELINE INTERFEROMETRY MEASURED PROPER MOTION AND PARALLAX OF THE ?-RAY MILLISECOND PULSAR PSR J0218+4232

    SciTech Connect (OSTI)

    Du, Yuanjie; Chen, Ding; Yang, Jun; Campbell, Robert M.; Janssen, Gemma; Stappers, Ben

    2014-02-20

    PSR J0218+4232 is a millisecond pulsar (MSP) with a flux density ?0.9 mJy at 1.4 GHz. It is very bright in the high-energy X-ray and ?-ray domains. We conducted an astrometric program using the European VLBI Network (EVN) at 1.6 GHz to measure its proper motion and parallax. A model-independent distance would also help constrain its ?-ray luminosity. We achieved a detection of signal-to-noise ratio S/N >37 for the weak pulsar in all five epochs. Using an extragalactic radio source lying 20 arcmin away from the pulsar, we estimate the pulsar's proper motion to be ?{sub ?}cos ? = 5.35 ± 0.05 mas yr{sup –1} and ?{sub ?} = –3.74 ± 0.12 mas yr{sup –1}, and a parallax of ? = 0.16 ± 0.09 mas. The very long baseline interferometry (VLBI) proper motion has significantly improved upon the estimates from long-term pulsar timing observations. The VLBI parallax provides the first model-independent distance constraints: d=6.3{sub ?2.3}{sup +8.0} kpc, with a corresponding 3? lower-limit of d = 2.3 kpc. This is the first pulsar trigonometric parallax measurement based solely on EVN observations. Using the derived distance, we believe that PSR J0218+4232 is the most energetic ?-ray MSP known to date. The luminosity based on even our 3? lower-limit distance is high enough to pose challenges to the conventional outer gap and slot gap models.

  11. NuSTAR OBSERVATIONS AND BROADBAND SPECTRAL ENERGY DISTRIBUTION MODELING OF THE MILLISECOND PULSAR BINARY PSR J1023+0038

    SciTech Connect (OSTI)

    Li, K. L.; Kong, A. K. H.; Tam, P. H. T.; Jin, Ruolan [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Takata, J.; Cheng, K. S. [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Hui, C. Y., E-mail: lilirayhk@gmail.com, E-mail: akong@phys.nthu.edu.tw, E-mail: takata@hku.hk [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of)

    2014-12-20

    We report the first hard X-ray (3-79 keV) observations of the millisecond pulsar (MSP) binary PSR J1023+0038 using NuSTAR. This system has been shown transiting between a low-mass X-ray binary (LMXB) state and a rotation-powered MSP state. The NuSTAR observations were taken in both LMXB state and rotation-powered state. The source is clearly seen in both states up to ?79 keV. During the LMXB state, the 3-79 keV flux is about a factor of 10 higher than in the rotation-powered state. The hard X-rays show clear orbital modulation during the X-ray faint rotation-powered state but the X-ray orbital period is not detected in the X-ray bright LMXB state. In addition, the X-ray spectrum changes from a flat power-law spectrum during the rotation-powered state to a steeper power-law spectrum in the LMXB state. We suggest that the hard X-rays are due to the intrabinary shock from the interaction between the pulsar wind and the injected material from the low-mass companion star. During the rotation-powered MSP state, the X-ray orbital modulation is due to Doppler boosting of the shocked pulsar wind. At the LMXB state, the evaporating matter of the accretion disk due to the gamma-ray irradiation from the pulsar stops almost all the pulsar wind, resulting in the disappearance of the X-ray orbital modulation.

  12. Beta/alpha continuous air monitor

    DOE Patents [OSTI]

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

    1989-01-01

    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.

  13. Beta/alpha continuous air monitor

    DOE Patents [OSTI]

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

    1988-06-27

    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.

  14. 4$?$ detector for study of Zeno effect using 220Rn -> 216Po alpha->alpha correlated chains

    E-Print Network [OSTI]

    L. Nadderd; Y. S. Tsyganov; K. Subotic; A. N. Polyakov; Y. V. Lobanov; A. V. Rykhlyuk

    2015-06-08

    First test of the 4pi detector for study of exponential law of radioactive decay and possibility of observation of Zeno effect [1-3], measuring the mean life of 216Po is presented. This detector consists of two surface-barrier n-Si(Au) detectors placed in the close contact ( measured half-live of 216Po of 143.5 (0.6) ms is in agreement with literature sources. It is shown, that for the definite source the random background correlation counts are mostly caused by the 220Rn - 216Po alpha activities and that it is not an easy task to decrease a background level of units of percents in the time region >4T1/2. Both, the data acquisition system and the vacuum chamber design are presented in brief.

  15. 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 

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

    E-Print Network [OSTI]

    Vittorio Del Duca; Claude Duhr; Gabor Somogyi; Francesco Tramontano; Zoltan Trocsanyi

    2015-02-05

    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.

  17. Fast Proton Decay

    E-Print Network [OSTI]

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

    2010-09-10

    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.

  18. Handbook on string decay

    E-Print Network [OSTI]

    Roberto Iengo; Jorge G. Russo

    2006-02-20

    We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of time -- the ``squashing ellipse''. This string interpolates between the folded string with maximum angular momentum and the pulsating circular string. We explicitly compute the quantum decay rate for the corresponding quantum state, and verify the basic rules that we propose. Finally, we give a more general (4-parameter) family of closed string solutions representing rotating and pulsating elliptical strings.

  19. Double Beta Decay Experiments

    SciTech Connect (OSTI)

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

    2011-11-23

    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.

  20. Decay of Hypernuclei

    E-Print Network [OSTI]

    A. Parreño; C. Bennhold; A. Ramos

    1999-02-17

    We present a nonrelativistic transition potential for the weak strangeness-changing reaction $\\Lambda N \\to NN$. The potential is based on a one meson exchange model (OME), where, in addition to the long-ranged pion, the exchange of the pseudoscalar $K, \\eta$, as well as the vector $\\rho, \\omega, K^*$ mesons is considered. Results obtained for different hypernuclear decay observables are compared to the available experimental data.

  1. Radioactive decay data tables

    SciTech Connect (OSTI)

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

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

    E-Print Network [OSTI]

    Thomas Kluge

    2006-10-13

    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.

  3. Evidence for an alpha cluster condensed state in 16O(alpha,alpha') at 400 MeV

    E-Print Network [OSTI]

    T. Wakasa; E. Ihara; K. Fujita; Y. Funaki; K. Hatanaka; H. Horiuchi; M. Itoh; J. Kamiya; G. Ropke; H. Sakaguchi; N. Sakamoto; Y. Sakemi; P. Schuck; Y. Shimizu; M. Takashina; S. Terashima; A. Tohsaki; M. Uchida; H. P. Yoshida; M. Yosoi

    2006-11-13

    Inelastic $\\alpha$ scattering on 16O is studied at 400 MeV by using an ice target. Near the 4-alpha breakup threshold of 14.4 MeV, a broad peak is observed at an excitation energy of 13.6+/-0.2 MeV with a width of 0.6+/-0.2 MeV. The spin-parity is estimated to be 0+ from the momentum-transfer dependence. The observed width is significantly larger than those of the neighboring 0+ states indicating a state with a well-developed alpha cluster structure. The magnitude of the cross section is sensitive to the density distribution of the constituent alpha clusters. The observed cross section is consistent with the theoretical prediction for the alpha cluster condensed state characterized by its dilute density distribution with a large root-mean-square radius of about 4.3 fm.

  4. High-alpha space trucks

    SciTech Connect (OSTI)

    Cook, L.M. [Ball Aerospace and Technology Corp. 1600 Commerce St. MS CO-9 Boulder, Colorado80301 (United States); Ball, J. [McDonnel Douglas Aerospace 5301 Bolsa Ave. MS 13-3 Huntington Beach, California92647 (United States)

    1997-01-01

    Vertically-landing Reusable Launch Vehicles (RLVs) are the best hope of building a true {open_quotes}Space Truck{close_quotes} with current technology. Because they do not require a low angle-of-attack (AOA, or alpha) horizontal landing, they can be designed to operate exclusively at very high angles-of-attack. This offers savings in vehicle dry weight and complexity, which can be traded for significantly heavier payload, more ascent velocity, or extra design margin. The price for abandoning low angle-of-attack flight is reduced crossrange. To quantify the potential weight reduction, a trade study was performed to determine the relationship between a vehicle{close_quote}s maximum crossrange (angle-of-attack) and it{close_quote}s dry weight (payload margin). At the study conclusion, three vertically-landing (VL) vehicles provided multiple points on a payload weight vs. maximum crossrange curve, showing significant payload increases as crossrange is sacrificed. This is primarily the result of being able to simplify the structure, fly a cooler entry trajectory, and be aerodynamically stable through the entire flight. This reduces subsystem requirements and complexity, enhancing reliability. Further benefits are realized in reduced landing propellant requirements and simplifying or eliminating the {open_quotes}rotation{close_quotes} maneuver. This paper also suggests unique operability solutions that adapt high-alpha vehicles to traditional high-crossrange missions such as the polar {open_quotes}once-around{close_quotes} flight, and proposes a small scale drop-test program to prove the subsonic and landing portion of the flight envelope. {copyright} {ital 1997 American Institute of Physics.}

  5. Particle decay studies at or near closed shells

    SciTech Connect (OSTI)

    Toth, K.S.

    1985-01-01

    We summarize briefly two sets of investigations. In the first one ..cap alpha..-decay rates of neutron-deficient even-even Pb isotopes were studied by using the UNISOR separator on-line at the Holifield Heavy Ion Research Facility. These data indicate that midway between N = 82 and N = 126, the Z = 82 shell gap may not exist. The second investigation, carried out at the Lawrence Berkeley Laboratory 88-Inch Cyclotron and SuperHILAC, has dealt with the delayed-proton decays of the N = 81 precursors /sup 147/Dy, /sup 149/Er, and /sup 151/Yb. All three proton spectra have sharp peaks and thus provide evidence for greatly reduced level densities in the N = 82 proton emitting nuclei /sup 147/Tb, /sup 149/Ho, and /sup 151/Tm. 6 refs., 3 figs.

  6. Determination of alpha_s from the QCD static energy: an update

    E-Print Network [OSTI]

    Alexei Bazavov; Nora Brambilla; Xavier Garcia i Tormo; Peter Petreczky; Joan Soto; Antonio Vairo

    2014-11-04

    We present an update of our determination of the strong coupling alpha_s from the quantum chromodynamics static energy. This updated analysis includes new lattice data, at smaller lattice spacings and reaching shorter distances, the use of better suited perturbative expressions to compare with data in a wider distance range, and a comprehensive and detailed estimate of the error sources that contribute to the uncertainty of the final result. Our updated value for alpha_s at the Z-mass scale, M_Z, is alpha_s(M_Z)=0.1166^{+0.0012}_{-0.0008}, which supersedes our previous result.

  7. 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

    2015-01-01

    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.

  8. Dark Matter from Late Invisible Decays to/of Gravitinos

    E-Print Network [OSTI]

    Rouzbeh Allahverdi; Bhaskar Dutta; Farinaldo S. Queiroz; Louis E. Strigari; Mei-Yu Wang

    2014-12-27

    In this work, we sift a simple supersymmetric framework of late invisible decays to/of the gravitino. We investigate two cases where the gravitino is the lightest supersymmetric particle or the next-to-lightest supersymmetric particle. The next-to-lightest supersymmetric particle decays into two dark matter candidates and has a long lifetime due to gravitationally suppressed interactions. However, because of the absence of any hadronic or electromagnetic products, it satisfies the tight bounds set by big bang nucleosynthesis and cosmic microwaved background. One or both of the dark matter candidates produced in invisible decays can contribute to the amount of dark radiation and suppress perturbations at scales that are being probed by the galaxy power spectrum and the Lyman-alpha forest data. We show that these constraints are satisfied in large regions of the parameter space and, as a result, the late invisible decays to/of the gravitino can be responsible for the entire dark matter relic abundance.

  9. Alpha1 and Alpha2 Integrins Mediate Invasive Activity of Mouse Mammary Carcinoma Cells through Regulation of Stromelysin-1 Expression

    SciTech Connect (OSTI)

    Lochter, Andre; Navre, Marc; Werb, Zena; Bissell, Mina J

    1998-06-29

    Tumor cell invasion relies on cell migration and extracellular matrix proteolysis. We investigated the contribution of different integrins to the invasive activity of mouse mammary carcinoma cells. Antibodies against integrin subunits {alpha}6 and {beta}1, but not against {alpha}1 and {alpha}2, inhibited cell locomotion on a reconstituted basement membrane in two-dimensional cell migration assays, whereas antibodies against {beta}1, but not against a6 or {alpha}2, interfered with cell adhesion to basement membrane constituents. Blocking antibodies against {alpha}1 integrins impaired only cell adhesion to type IV collagen. Antibodies against {alpha}1, {alpha}2, {alpha}6, and {beta}1, but not {alpha}5, integrin subunits reduced invasion of a reconstituted basement membrane. Integrins {alpha}1 and {alpha}2, which contributed only marginally to motility and adhesion, regulated proteinase production. Antibodies against {alpha}1 and {alpha}2, but not {alpha}6 and {beta}1, integrin subunits inhibited both transcription and protein expression of the matrix metalloproteinase stromelysin-1. Inhibition of tumor cell invasion by antibodies against {alpha}1 and {alpha}2 was reversed by addition of recombinant stromelysin-1. In contrast, stromelysin-1 could not rescue invasion inhibited by anti-{alpha}6 antibodies. Our data indicate that {alpha}1 and {alpha}2 integrins confer invasive behavior by regulating stromelysin-1 expression, whereas {alpha}6 integrins regulate cell motility. These results provide new insights into the specific functions of integrins during tumor cell invasion.

  10. Dark decay of Top quark

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

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

    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

  11. 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

    2014-04-01

    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.

  12. Rare B Decays

    SciTech Connect (OSTI)

    Jackson, P.D.; /Victoria U.

    2006-02-24

    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 -}.

  13. 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.

  14. 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)

    2013-10-20

    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.

  15. Calibrations of alpha Cen A & B

    E-Print Network [OSTI]

    Morel, P; Lebreton, Y; Thévenin, F; Berthomieu, G

    2000-01-01

    Detailed evolutionary models of the visual binary alpha Centauri, including pre main-sequence evolution, have been performed using the masses recently determined by Pourbaix et al. (1999). Models have been constructed using the CEFF equation of state, OPAL opacities, NACRE thermonuclear reaction rates and microscopic diffusion. A chi^2-minimization is performed to derive the most reliable set of modeling parameters wp={t_alpha Cen, Yi, [Fe/H]i, alpha A, alpha B}, where t alpha Cen is the age of the system, Yi the initial helium content, [Fe/H]i the initial metallicity and, alpha A and alpha B the convection parameters of the two components. Using the basic Bohm-Vitense (1958) mixing-length theory of convection, we derive wp BV={2710 Myr, 0.284,0.257, 1.53, 1.57}. We obtain a noticeably smaller age than estimated previously, in agreement with Pourbaix et al. (1999), mainly because of the larger masses. If convective core overshoot is considered we get wp ov={3530 Myr, 0.279,0.264,1.64,1.66}. The use of Canuto ...

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

    E-Print Network [OSTI]

    Xinqiang Li; Yadong Yang

    2006-06-12

    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.

  17. Search for Two-Particle Muon Decay to Positron and Goldstone Massless Boson (FAMILON)

    E-Print Network [OSTI]

    Andreev, V A; Demidova, E V; Duginov, V N; Elkin, Y V; Gordeev, V A; Gritsai, K I; Gustov, S A; Ivochkin, V G; Karasev, E M; Khlopov, M Ya; Komarov, E N; Kosianenko, S V; Krivshich, A G; Levchenko, M P; Mamedov, T N; Mirokhin, I V; Olshevsky, V G; Scheglov, Y; Scherbakov, G V; Schkurenko, Y P; Sokolov, A Yu; Stoykov, A V; Vorobyev, S I; Zhdanov, A A; Zhukov, V A; Elkin, Yu.V.; Scheglov, Yu.A.; Schkurenko, Yu.P.

    2006-01-01

    The experimental test of possible expansion for the Higgs sector is proposed. The lepton family violation will be studied. To reach this goal we are going to carry out the search for the scalar Goldstone boson in the neutrinoless muon decay mu+ to e+ and alpha. The asymmetry of the muon decay near the high energy edge of Michel spectrum is to be measured. To examine previous TRIUMF data the experiment FAMILON is prepared at the surface muon beam of JINR (Dubna) accelerator. The setup consist of the precision magnetic spectrometer and the device for muSR - analysis.

  18. Search for Two-Particle Muon Decay to Positron and Goldstone Massless Boson (FAMILON)

    E-Print Network [OSTI]

    V. A. Andreev; V. S. Demidov; E. V. Demidova; V. N. Duginov; Yu. V. Elkin; V. A. Gordeev; K. I. Gritsai; S. A. Gustov; V. G. Ivochkin; E. M. Karasev; M. Yu. Khlopov; E. N. Komarov; S. V. Kosianenko; A. G. Krivshich; M. P. Levchenko; T. N. Mamedov; I. V. Mirokhin; V. G. Olshevsky; Yu. A. Scheglov; G. V. Scherbakov; A. Yu. Sokolov; Yu. P. Schkurenko; A. V. Stoykov; S. I. Vorobyev; A. A. Zhdanov; V. A. Zhukov

    2006-12-28

    The experimental test of possible expansion for the Higgs sector is proposed. The lepton family violation will be studied. To reach this goal we are going to carry out the search for the scalar Goldstone boson in the neutrinoless muon decay mu+ to e+ and alpha. The asymmetry of the muon decay near the high energy edge of Michel spectrum is to be measured. To examine previous TRIUMF data the experiment FAMILON is prepared at the surface muon beam of JINR (Dubna) accelerator. The setup consist of the precision magnetic spectrometer and the device for muSR - analysis.

  19. NUCLEAR DECAY SCHEMES IN THE ACTINIUM FAMILY

    E-Print Network [OSTI]

    Pilger Jr, Richard C.

    2010-01-01

    magnetic alpha-particle and electron high-resolution spectrographs and scintillation gamma-ray spectrometers,

  20. Standard Neutrino Spectrum from B-8 Decay

    E-Print Network [OSTI]

    John N. Bahcall; E. Lisi; D. E. Alburger; L. De Braeckeleer; S. J. Freedman; J. Napolitano

    1996-04-19

    We present a systematic evaluation of the shape of the neutrino energy spectrum produced by beta-decay of $^8$B. We place special emphasis on determining the range of uncertainties permitted by existing laboratory data and theoretical ingredients (such as forbidden and radiative corrections). We review and compare the available experimental data on the $^8$B$(\\beta^+){}^8$Be$(2\\alpha)$ decay chain. We analyze the theoretical and experimental uncertainties quantitatively. We give a numerical representation of the best-fit (standard-model) neutrino spectrum, as well as two extreme deviations from the standard spectrum that represent the total (experimental and theoretical) effective $\\pm3\\sigma$ deviations. Solar neutrino experiments that are currently being developed will be able to measure the shape of the $^8$B neutrino spectrum above about 5 MeV. An observed distortion of the $^8$B solar neutrino spectrum outside the range given in the present work could be considered as evidence, at an effective significance level greater than three standard deviations, for physics beyond the standard electroweak model. We use the most recent available experimental data on the Gamow--Teller strengths in the $A=37$ system to calculate the $^8$B neutrino absorption cross section on chlorine: $\\sigma_{\\rm Cl}=(1.14\\pm0.11)\\times10^{-42}$~cm$^2$ ($\\pm3\\sigma$ errors). The chlorine cross section is also given as a function of the neutrino energy. The $^8$B neutrino absorption cross section in gallium is $\\sigma_{\\rm Ga}=(2.46^{+2.1}_{-1.1})\\times10^{-42}$ cm$^2$ ($\\pm3\\sigma$ errors).

  1. On the Behavior of the Effective QCD Coupling {alpha}{sub {tau}}(s)at Low Scales

    SciTech Connect (OSTI)

    Brodsky, Stanley J.

    2002-12-11

    The hadronic decays of the {tau} lepton can be used to determine the effective charge {alpha}{tau}(m{sub {tau}{prime}}{sup 2}) for a hypothetical {tau}-lepton with mass in the range 0 < m{sub {tau}{prime}} < m{sub {tau}}. This definition provides a fundamental definition of the QCD coupling at low mass scales. We study the behavior of {alpha}{sub {tau}} at low mass scales directly from first principles and without any renormalization-scheme dependence by looking at the experimental data from the OPAL Collaboration. The results are consistent with the freezing of the physical coupling at mass scales s = m{sub {tau}{prime}}{sup 2} of order 1 GeV{sup 2} with a magnitude {alpha}{sub {tau}} {approx} 0.9 {+-} 0.1.

  2. Soudan 2 nucleon decay experiment

    SciTech Connect (OSTI)

    Thron, J.L.

    1986-01-01

    The Soudan 2 nucleon decay experiment consists of a 1.1 Kton fine grained iron tracking calorimeter. It has a very isotropic detection structure which along with its flexible trigger will allow detection of multiparticle and neutrino proton decay modes. The detector has now entered its construction stage.

  3. NEW APPROACHES TO CONFINED ALPHA DIAGNOSTICS

    SciTech Connect (OSTI)

    FISHER,R.K

    2004-04-01

    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.

  4. 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)

    2004-10-01

    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.

  5. Nuclear diagnostic for fast alpha particles

    DOE Patents [OSTI]

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

    1983-11-23

    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.

  6. Transport of Radioactive Material by Alpha Recoil

    SciTech Connect (OSTI)

    Icenhour, A.S.

    2005-05-19

    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.

  7. Alpha particles in effective field theory

    SciTech Connect (OSTI)

    Caniu, C.

    2014-11-11

    Using an effective field theory for alpha (?) particles at non-relativistic energies, we calculate the strong scattering amplitude modified by Coulomb corrections for a system of two ?s. For the strong interaction, we consider a momentum-dependent interaction which, in contrast to an energy dependent interaction alone [1], could be more useful in extending the theory to systems with more than two ? particles. We will present preliminary results of our EFT calculations for systems with two alpha particles.

  8. Calibrations of alpha Cen A & B

    E-Print Network [OSTI]

    P. Morel; J. Provost; Y. Lebreton; F. Thevenin; G. Berthomieu

    2000-10-10

    Detailed evolutionary models of the visual binary alpha Centauri, including pre main-sequence evolution, have been performed using the masses recently determined by Pourbaix et al. (1999). Models have been constructed using the CEFF equation of state, OPAL opacities, NACRE thermonuclear reaction rates and microscopic diffusion. A chi^2-minimization is performed to derive the most reliable set of modeling parameters wp={t_alpha Cen, Yi, [Fe/H]i, alpha A, alpha B}, where t alpha Cen is the age of the system, Yi the initial helium content, [Fe/H]i the initial metallicity and, alpha A and alpha B the convection parameters of the two components. Using the basic Bohm-Vitense (1958) mixing-length theory of convection, we derive wp BV={2710 Myr, 0.284,0.257, 1.53, 1.57}. We obtain a noticeably smaller age than estimated previously, in agreement with Pourbaix et al. (1999), mainly because of the larger masses. If convective core overshoot is considered we get wp ov={3530 Myr, 0.279,0.264,1.64,1.66}. The use of Canuto & Mazitelli (1991, 1992) convection theory leads to the set wp CM={4086 Myr, 0.271, 0.264, 0.964, 0.986}. Using the observational constraints adopted by Guenther & Demarque (2000), and the basic mixing-length theory, we obtain wp GD={5640 Myr, 0.300, 0.296, 1.86, 1.97} and surface lithium depletions close to their observed values. A seismological analysis of our calibrated models has been performed. The determination of large and small spacings between the frequencies of acoustic oscillations from seismic observations would help to discriminate between the models of alpha Cen computed with different masses and to confirm or rules out the new determination of masses.

  9. Top decays in extended models

    SciTech Connect (OSTI)

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2009-04-20

    Top quark decays are interesting as a mean to test the Standard Model (SM) predictions. The Cabbibo-Kobayashi-Maskawa (CKM)-suppressed process t{yields}cWW, and the rare decays t{yields}cZ, t{yields}H{sup 0}+c, and t{yields}c{gamma} an excellent window to probe the predictions of theories beyond the SM. We evaluate the flavor changing neutral currents (FCNC) decay t{yields}H{sup 0}+c in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions; the FCNC decays may place at tree level and are only supressed by the mixing between ordinary top and charm quarks. We also comment on the decay process t{yields}c+{gamma}, which involves radiative corrections.

  10. Preparation and properties of (R)-(-)-1-azabicyclo(2. 2. 2)oct-3-yl- (R)-(+)-alpha-hydroxy-alpha-(4-( sup 125 I)iodophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2. 2. 2)oct-3-yl-(S)-(-)-alpha-hydroxy-alpha- (4-( sup 125 I)iodophenyl)-alpha-phenyl acetate as potential radiopharmaceuticals

    SciTech Connect (OSTI)

    Cohen, V.I.; Rzeszotarski, W.J.; Gibson, R.E.; Fan, L.H.; Reba, R.C. )

    1989-10-01

    rac-4-Nitrobenzilic acid was synthesized and resolved with quinidine and quinine to give the corresponding (R)- and (S)-salts. The resolved diastereomeric salts were converted to (R)- and (S)-4-nitrobenzilic acids and subsequent esterification gave their corresponding ethyl esters. Transesterification with (R)-(-)-3-quinuclidinol afforded (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)-alpha-hydroxy-alpha- (4-nitrophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy- alpha-(4-nitrophenyl)-alpha-phenyl acetate. After hydrogenation, the (R,R)- and (R,S)-amines were converted to the respective triazene derivatives. The triazene derivatives reacted with sodium ({sup 125}I)iodide to give (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)- alpha-hydroxy-alpha-(4-({sup 125}I)iodophenyl)-alpha-phenyl acetate and (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy- alpha-(4-(125I)iodophenyl)-alpha-phenyl acetate. The evaluation of their affinities to muscarinic acetylcholine receptors (MAcChR) shows that (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(S)-(-)-alpha-hydroxy-alpha-(4- ({sup 125}I)iodophenyl)-alpha-phenyl acetate exhibits an affinity for the MAcChR from corpus striatum that is approximately threefold lower than that of (R)-(-)-1-azabicyclo(2.2.2)oct-3-yl-(R)-(+)-alpha-hydroxy-alpha-(4- ({sup 125}I)iodophenyl)-alpha-phenyl acetate.

  11. Proton Decay and the Planck Scale

    E-Print Network [OSTI]

    Larson, Daniel T.

    2009-01-01

    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

  12. Search for neutrinoless decays of the ? lepton

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-02-01

    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...

  13. 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)

    2002-07-30

    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.

  14. Sudden transition from naked atom decay to dressed atom decay

    E-Print Network [OSTI]

    Wei Zhu; D. L. Zhou

    2015-07-09

    The studies on quantum open system play key roles not only in fundamental problems in quantum mechanics but also in quantum computing and information processes. Here we propose a scheme to use a one dimensional coupling cavity array (CCA) as an artificial electromagnetic environment of a two-level atom. For a finite length of CCA, we find that after a turning time the population of excited state deviates suddenly from the exponential decay. We show that physically this phenomena corresponds to a transition from a naked atom decay to a dressed state decay. We hope that our finding will promote the studies on quantum system with a finite size environment.

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

    SciTech Connect (OSTI)

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

    1985-08-01

    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.

  16. DOSIMETRY; RADIOISOTOPES; DECAY; ACCURACY; DATA COMPILATION;...

    Office of Scientific and Technical Information (OSTI)

    Radioactive decay data tables Kocher, D.C. 61 RADIATION PROTECTION AND DOSIMETRY; RADIOISOTOPES; DECAY; ACCURACY; DATA COMPILATION; DOSIMETRY; M CODES; COMPUTER CODES; DATA;...

  17. The strong coupling from the revised ALEPH data for hadronic $?$ decays

    E-Print Network [OSTI]

    Diogo Boito; Maarten Golterman; Kim Maltman; James Osborne; Santiago Peris

    2015-03-08

    We apply an analysis method previously developed for the extraction of the strong coupling from the OPAL data to the recently revised ALEPH data for non-strange hadronic $\\tau$ decays. Our analysis yields the values $\\alpha_s(m_\\tau^2)=0.296\\pm 0.010$ using fixed-order perturbation theory, and $\\alpha_s(m_\\tau^2)=0.310\\pm 0.014$ using contour-improved perturbation theory. Averaging these values with our previously obtained values from the OPAL data, we find $\\alpha_s(m_\\tau^2)=0.303\\pm 0.009$, respectively, $\\alpha_s(m_\\tau^2)=0.319\\pm 0.012$. We present a critique of the analysis method employed previously, for example in analyses by the ALEPH and OPAL collaborations, and compare it with our own approach. Our conclusion is that non-perturbative effects limit the accuracy with which the strong coupling, an inherently perturbative quantity, can be extracted at energies as low as the $\\tau$ mass. Our results further indicate that systematic errors on the determination of the strong coupling from analyses of hadronic $\\tau$-decay data have been underestimated in much of the existing literature.

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

    E-Print Network [OSTI]

    E. El aaoud

    1998-01-08

    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^{+}\

  19. Neutrinoless Double Beta Decay Constraints

    E-Print Network [OSTI]

    Hiroaki Sugiyama

    2003-07-25

    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.

  20. Wave Decay in MHD Turbulence

    E-Print Network [OSTI]

    Andrey Beresnyak; Alex Lazarian

    2008-05-06

    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.

  1. Piper Alpha and Independence Marion King Hubbert (1903 1989) Piper Alpha (6 July 1988)

    E-Print Network [OSTI]

    be a second Piper Alpha tragedy for Scotland if its historical effect on oil production has not been by the Yes campaign. Following Piper Alpha, oil production was deliberately cut back in order to allow assessment of Scotland's likely remaining oil wealth (including new finds). The Hubbert production forecast

  2. The decay of hot nuclei

    SciTech Connect (OSTI)

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

    1988-11-01

    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.

  3. Infrared Fixed Point in the Strong Running Coupling: Unraveling the ?I=1/2 puzzle in K-Decays

    E-Print Network [OSTI]

    R. J. Crewther; Lewis C. Tunstall

    2013-06-19

    In this talk, we present an explanation for the Delta I = 1/2 rule in K-decays based on the premise of an infrared fixed point alpha_IR in the running coupling alpha_s of quantum chromodynamics (QCD) for three light quarks u,d,s. At the fixed point, the quark condensate spontaneously breaks scale and chiral SU(3)_L x SU(3)_R symmetry. Consequently, the low-lying spectrum contains nine Nambu-Goldstone bosons: pi,K,eta and a QCD dilaton sigma. We identify sigma as the f_0(500) resonance and construct a chiral-scale perturbation theory CHPT_sigma for low-energy amplitudes expanded in alpha_s about alpha_IR. The Delta I = 1/2 rule emerges in the leading order of CHPT_sigma through a sigma-pole term K_S --> sigma --> 2 pi, with a K_S-sigma coupling fixed by data on 2 gamma --> 2 pi^0 and K_S --> 2 gamma. We also determine R_IR ~ 5 for the nonperturbative Drell-Yan ratio at alpha_IR.

  4. Non-exponential Auger decay

    E-Print Network [OSTI]

    Ishkhanyan, A M

    2015-01-01

    We discuss the possibility of non-exponential Auger decay of atoms irradiated by X-ray photons. This effect can occur at times, which are greater than the lifetime of a system under consideration. The mechanism for non-exponential depletion of an initial quasi-stationary state is the cutting of the electron energy spectrum of final continuous states at small energies. Then the Auger decay amplitude obeys power-law dependence on long observation times.

  5. CP violation in sbottom decays

    E-Print Network [OSTI]

    Frank F. Deppisch; Olaf Kittel

    2010-03-26

    We study CP asymmetries in two-body decays of bottom squarks into charginos and tops. These asymmetries probe the SUSY CP phases of the sbottom and the chargino sector in the Minimal Supersymmetric Standard Model. We identify the MSSM parameter space where the CP asymmetries are sizeable, and analyze the feasibility of their observation at the LHC. As a result, potentially detectable CP asymmetries in sbottom decays are found, which motivates further detailed experimental studies for probing the SUSY CP phases.

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

    SciTech Connect (OSTI)

    Belli, P.; Di Marco, A.; Bernabei, R.; D'Angelo, S.; Cappella, F.; D'Angelo, A.; Incicchitti, A.; Cerulli, R.; Di Vacri, M. L.; Laubenstein, M.; Nisi, S.; Danevich, F. A.; Kobychev, V. V.; Poda, D. V.; Tretyak, V. I.; Kovtun, G. P.; Kovtun, N. G.; Shcherban, A. P.; Solopikhin, D. A.; Polischuk, O. G.; and others

    2013-12-30

    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.

  7. Signature of nonexponential nuclear decay

    E-Print Network [OSTI]

    A Ray; A K Sikdar; A De

    2015-03-18

    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

  8. Alternating current long range alpha particle detector

    DOE Patents [OSTI]

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

    1993-02-16

    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.

  9. Synthesis of peptide .alpha.-thioesters

    DOE Patents [OSTI]

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

    2008-08-19

    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.

  10. Fan-less long range alpha detector

    DOE Patents [OSTI]

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

    1994-05-10

    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.

  11. TeV gamma rays from millisecond pulsars. [PSR 1937+21; PSR 1953+29; PSR 1855+09; PSR 1957+20; PSR 1516+02 A; PSR 1620-26; PSR 0021-72; PSR 1821-24; Cyg X-3

    SciTech Connect (OSTI)

    Bowden, C.C.G.; Bradbury, S.M.; Brazier, K.T.S.; Carraminana, A.; Chadwick, P.M.; Dipper, N.A.; Edwards, P.J.; Lincoln, E.W.; Mannings, V.G.; McComb, T.J.L.; Orford, K.J.; Rayner, S.M.; Turver, K.E. )

    1991-04-05

    We summarize here the results of the VHE gamma ray study of millisecond pulsars made over seven years by the Durham group. In addition to reporting observations made recently with the Mark III and IV telescopes at Narrabri, Australia, we consider the application of new analysis techniques to earlier data taken using telescopes at Dugway, USA. Pulsed VHE {gamma}-rays have been detected from three of the eight millisecond pulsars observed; we compare our results with the predictions of a theory of VHE emission from millisecond pulsars.

  12. Spin-dependent energy distribution of B-hadrons from polarized top decays considering the azimuthal correlation rate

    E-Print Network [OSTI]

    S. M. Moosavi Nejad

    2015-06-29

    In our previous work, we studied the polar distribution of the scaled energy of bottom-flavored hadrons from polarized top quark decays $t(\\uparrow)\\rightarrow W^++b(\\rightarrow X_b)$, using two different helicity coordinate systems. Basically, the energy distributions are governed by the unpolarized, polar and azimuthal rate functions which are related to the density matrix elements of the decay $t(\\uparrow)\\rightarrow W^++b$. Here we present, for the first time, the analytical expressions for the ${\\cal O}(\\alpha_s)$ radiative corrections to the differential azimuthal decay rates of the partonic process $t(\\uparrow)\\rightarrow b+W^+(+g)$ in two helicity systems, which are needed to study the azimuthal distribution of the energy spectrum of the B-hadron produced in polarized top quark decays. Our predictions of the hadron energy distributions enable us to deepen our knowledge of the hadronization process and to determine the polarization states of top quarks.

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

    SciTech Connect (OSTI)

    Robert Hayes, Craig Marianno

    2007-01-01

    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.

  14. Transformer Recharging with Alpha Channeling in Tokamaks

    SciTech Connect (OSTI)

    N.J. Fisch

    2009-12-21

    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. __________________________________________________

  15. Charmless non-leptonic B_s decays to PP, PV and VV final states in the pQCD approach

    E-Print Network [OSTI]

    Ahmed Ali; Gustav Kramer; Ying Li; Cai-Dian Lu; Yue-Long Shen; Wei Wang; Yu-Ming Wang

    2007-08-21

    We calculate the CP-averaged branching ratios and CP-violating asymmetries of a number of two-body charmless hadronic decays $\\bar{B_s^0} \\to PP, PV, VV$ in the perturbative QCD (pQCD) approach to leading order in $\\alpha_s$ (here $P$ and $V$ denote light pseudoscalar and vector mesons, respectively). The mixing-induced CP violation parameters are also calculated for these decays. We also predict the polarization fractions of $B_s \\to VV$ decays and find that the transverse polarizations are enhanced in some penguin dominated decays such as $\\bar{B_s^0} \\to K ^{*}\\bar{K^{*}}$, $K ^{*}\\rho$. Some of the predictions worked out here can already be confronted with the recently available data from the CDF collaboration on the branching ratios for the decays $ \\bar{B_s^0} \\to K^+\\pi^-$, $ \\bar{B_s^0} \\to K^+K^-$ and the CP-asymmetry in the decay $ \\bar{B_s^0} \\to K^+\\pi^-$, and are found to be in agreement within the current errors. A large number of predictions for the branching ratios, CP-asymmetries and vector-meson polarizations in $\\bar{B_s^0}$ decays, presented in this paper and compared with the already existing results in other theoretical frameworks, will be put to stringent experimental tests in forthcoming experiments at Fermilab, LHC and Super B-factories.

  16. Signature of nonexponential nuclear decay

    E-Print Network [OSTI]

    Ray, A; De, A

    2015-01-01

    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...

  17. Study of alpha background in a dark matter detector

    E-Print Network [OSTI]

    Yegoryan, Hayk

    2010-01-01

    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 ...

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

    DOE Patents [OSTI]

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

    1998-06-09

    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.

  19. The effects of alpha particle irradiation on stainless steel 

    E-Print Network [OSTI]

    Shipp, John Douglas

    1999-01-01

    A Monte Carlo code was developed to calculate the alpha particle emission rate from WGPu. It yielded information pertaining to the alpha particle source strength at the WGPU and stainless steel interface as well as the damage production and He...

  20. Predicting Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

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

    2005-07-12

    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.

  1. Neutrinoless Double Beta Decay Experiments

    E-Print Network [OSTI]

    Alberto Garfagnini

    2014-08-11

    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.

  2. CP violation in charm decays

    E-Print Network [OSTI]

    Alberto Corrêa dos Reis; on behalf of the LHCb collaboration

    2013-08-06

    Results on CP violation searches in charm decays performed by the LHCb experiment are reviewed. These include an update of the measurement of the difference in time-integrated {\\em CP} asymmetry between $D^0\\to K^-K^+$ and $D^0\\to \\pi^-\\pi^+$ using $D^0$ from prompt $D^{*+}, a measurement of the same observable using an independent sample of $D^0$ from semileptonic B decays, and CP violation searches performed on charged $D$ mesons. All results have been released since FPCP 2012.

  3. Symmetry violations in nuclear and neutron $?$ decay

    E-Print Network [OSTI]

    K. K. Vos; H. W. Wilschut; R. G. E. Timmermans

    2015-09-14

    The role of $\\beta$ decay as a low-energy probe of physics beyond the Standard Model is reviewed. Traditional searches for deviations from the Standard Model structure of the weak interaction in $\\beta$ decay are discussed in the light of constraints from the LHC and the neutrino mass. Limits on the violation of time-reversal symmetry in $\\beta$ decay are compared to the strong constraints from electric dipole moments. Novel searches for Lorentz symmetry breaking in the weak interaction in $\\beta$ decay are also included, where we discuss the unique sensitivity of $\\beta$ decay to test Lorentz invariance. We end with a roadmap for future $\\beta$-decay experiments.

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

    E-Print Network [OSTI]

    Bahcall, John N.

    2009-01-01

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

  5. A Search for Neutrinoless Double Beta Decay of Te-130

    E-Print Network [OSTI]

    Bryant, Adam Douglas

    2010-01-01

    far unobserved, neutrinoless double beta decay is a possibleright for the neutrinoless double beta decay of 130 Te. Thisprocess, with neutrinoless double beta decay being the most

  6. Synthesis of rutherfordium isotopes in the {sup 238}U({sup 26}Mg, xn){sup 264-x}Rf reaction and study of their decay properties

    SciTech Connect (OSTI)

    Gates, J. M.; Garcia, M. A.; Dragojevic, I.; Folden, C. M. III; Nelson, S. L.; Nitsche, H.; Gregorich, K. E.; Stavsetra, L.; Sudowe, R.; Duellmann, Ch. E.; Dvorak, J.; Tuerler, A.; Eichler, R.; Loveland, W.; Pang, G. K.

    2008-03-15

    Isotopes of rutherfordium ({sup 258-261}Rf) were produced in irradiations of {sup 238}U targets with {sup 26}Mg beams. Excitation functions were measured for the 4n,5n, and 6n exit channels. Production of {sup 261}Rf in the 3n exit channel with a cross section of 28{sub -26}{sup +92} pb was observed. {alpha}-decay of {sup 258}Rf was observed for the first time with an {alpha}-particle energy of 9.05 {+-} 0.03 MeV and an {alpha}/total-decay branching ratio of 0.31 {+-} 0.11. In {sup 259}Rf, the electron capture/total-decay branching ratio was measured to be 0.15{+-}0.04. The measured half-lives for {sup 258}Rf, {sup 259}Rf, and {sup 260}Rf were 14.7{sub -1.0}{sup +1.2} ms, 2.5{sub -0.3}{sup +0.4} s, and 22.2{sub -2.4}{sup +3.0} ms, respectively, in agreement with literature data. The systematics of the {alpha}-decay Q-values and of the partial spontaneous fission half-lives were evaluated for even-even nuclides in the region of the N=152,Z=100 deformed shell. The influence of the N=152 shell on the {alpha}-decay Q-values for rutherfordium was observed to be similar to that of the lighter elements (96{<=}Z{<=}102). However, the N=152 shell does not stabilize the rutherfordium isotopes against spontaneous fission, as it does in the lighter elements (96{<=}Z{<=}102)

  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

    2014-11-28

    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. 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

    2014-10-16

    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.

  9. 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

    2015-03-02

    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.

  10. Alpha Cluster Model of Atomic Nuclei

    E-Print Network [OSTI]

    Sosin, Zbigniew; Kallunkathariyil, Jinesh; ?ukasik, Jerzy; Paw?owski, Piotr

    2015-01-01

    The description of the nuclear system in its ground state and at low excitations based on the equation of state (EoS) around the saturation density is presented. In the expansion of the EoS around the saturation point additional spin polarization terms are taken into account. In addition for atomic nuclei a correction of the average nucleonic energy for the surface energy is introduced. The ground state configurations for the N=Z even-even nuclei, obtained with the proposed EoS, exhibit a clear cluster structure. At the nuclear surface these clusters can be identified as alpha particles. Taking into account an additional interaction between clusters the binding energy and sizes of the considered nuclei are very accurately described. From properties of the {\\alpha} particle, 3He and t limits of the EoS parameters are established.

  11. Constraining neutrinoless double beta decay

    E-Print Network [OSTI]

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

    2011-11-23

    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.

  12. New Physics in $B$ decays

    E-Print Network [OSTI]

    Crivellin, Andreas

    2015-01-01

    While the LHC did not observe direct evidence for physics beyond the standard model, indirect hints for new physics were uncovered in the flavour sector in the decays $B\\to K^*\\mu^+\\mu^-$, $B\\to K\\mu^+\\mu^-/B\\to Ke^+e^-$, $B_s\\to\\phi\\mu^+\\mu^-$, $B\\to D^{(*)}\\tau\

  13. Rare decays at the Tevatron

    SciTech Connect (OSTI)

    Farrington, S.M.; /Liverpool U.

    2006-01-01

    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.

  14. J/psi-Pair Production at Large Momenta: Indications for Double-Parton Scatterings and Large alpha_s^5 Contributions

    E-Print Network [OSTI]

    Jean-Philippe Lansberg; Hua-Sheng Shao

    2014-10-31

    The recent observations of prompt J/psi-pair production by CMS at the LHC and by D0 at the Tevatron reveal the presence of different production mechanisms in different kinematical regions. We find out that next-to-leading-order single-parton-scattering contributions at alpha_s^5 dominate the yield at large transverse momenta of the pair. Our analysis further emphasises the importance of double-parton-scatterings --which are expected to dominate the yield at large rapidity differences-- at large invariant masses of the pair in the CMS acceptance. In addition, we provide the first exact --gauge-invariant and infrared-safe-- evaluation of a class of leading-P_T next-to-next-to-leading-order contributions, which are dominant in the region of large sub-leading transverse momenta, precisely where the colour-octet contributions can be non-negligible. Finally, we discuss the contribution from decays of excited charmonium states within both single- and double-parton scatterings and suggest measurements to distinguish them.

  15. The study of synchronous (by local time) changes of the statistical properties of thermal noise and alpha-activity fluctuations of a 239-Pu sample

    E-Print Network [OSTI]

    A. V. Kaminsky; S. E. Shnoll

    2006-05-06

    Experimentally obtained and analyzed fine structure of statistical distributions for two physically independent processes: alpha-decay rate fluctuations of Pu-239 sample in Pushchino (Moscow region, Russia) and equilibrium voltage fluctuations (Johnson noise) from metal-film resistor in Tbilisi (Georgia). Special investigation of histograms shape similarity in these processes demonstrated majority of previously studied effects, called - macroscopic fluctuations. Offered qualitative model of the observed effects.

  16. The Reflares and Outburst Evolution in the Accreting Millisecond Pulsar SAX J1808.4-3658: a Disk Truncated Near Co-rotation?

    E-Print Network [OSTI]

    Patruno, A; Curran, P A; D'Angelo, C; Fridriksson, J K; Russell, D M; Middleton, M; Wijnands, R

    2015-01-01

    The accreting millisecond X-ray pulsar SAX J1808.4--3658 shows peculiar low luminosity states known as "reflares" after the end of the main outburst. During this phase the X-ray luminosity of the source varies by up to three orders of magnitude in less than 1-2 days. The lowest X-ray luminosity observed reaches a value of ~1e32 erg/s, only a factor of a few brighter than its typical quiescent level. We investigate the 2008 and 2005 reflaring state of SAX J1808.4-3658 to determine whether there is any evidence for a change in the accretion flow with respect to the main outburst. We perform a multiwavelength photometric and spectral study of the 2005 and 2008 reflares with data collected during an observational campaign covering the near-infrared, optical, ultra-violet and X-ray band. We find that the NIR/optical/UV emission, expected to some from the outer accretion disk shows variations in luminosity which are 1--2 orders of magnitude shallower than in X-rays. The X-ray spectral state observed during the refl...

  17. A new seismic analysis of Alpha Centauri

    E-Print Network [OSTI]

    A. Thoul; R. Scuflaire; A. Noels; B. Vatovez; M. Briquet; M. -A. Dupret; J. Montalban

    2003-03-20

    Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological data obtained by Bouchy and Carrier (2001, 2002) do help improve our knowledge of the evolutionary status of the system. All the constraints are satisfied with a model which gives an age of about 6 Gyr for the binary.

  18. A new seismic analysis of Alpha Centauri

    E-Print Network [OSTI]

    Thoul, A; Noels, A; Vatovez, B; Briquet, M; Dupret, M A; Montalban, J

    2003-01-01

    Models of alpha Cen A & B have been computed using the masses determined by Pourbaix et al. (2002) and the data derived from the spectroscopic analysis of Neuforge and Magain (1997). The seismological data obtained by Bouchy and Carrier (2001, 2002) do help improve our knowledge of the evolutionary status of the system. All the constraints are satisfied with a model which gives an age of about 6 Gyr for the binary.

  19. Proton decay matrix elements from lattice QCD 

    E-Print Network [OSTI]

    Cooney, Paul

    2010-01-01

    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 ...

  20. Causes and Control of Wood Decay,

    E-Print Network [OSTI]

    1 Causes and Control of Wood Decay, Degradation & Stain #12;2 Contents Moisture .................................................................................3 Wood Degradation: Causes and Control..............................4 Weathering......................................................................................................4 Naturally Decay-resistant Species...........................................................5 Wood

  1. Nuclear matrix elements for double beta decay

    E-Print Network [OSTI]

    Vadim Rodin

    2009-10-30

    The present status of calculations of the nuclear matrix elements for neutrinoless double beta decay is reviewed. A proposal which allows in principle to measure the neutrinoless double beta decay Fermi matrix element is briefly described.

  2. Helicity fractions of W bosons from top quark decays at next-to-next-to-leading order in QCD

    SciTech Connect (OSTI)

    Czarnecki, Andrzej; Koerner, Juergen G.; Piclum, Jan H. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7, Canada and CERN Theory Division, CH-1211 Geneva 23 (Switzerland); Institut fuer Physik, Universitaet Mainz, 55099 Mainz (Germany); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada)

    2010-06-01

    Decay rates of unpolarized top quarks into longitudinally and transversally polarized W bosons are calculated to second order in the strong coupling constant {alpha}{sub s}. Including the finite bottom quark mass and electroweak effects, the standard model predictions for the W-boson helicity fractions are F{sub L}=0.687(5), F{sub +}=0.0017(1), and F{sub -}=0.311(5).

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

    E-Print Network [OSTI]

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

    2015-03-27

    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.

  4. Detection of alpha radiation in a beta radiation field

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  5. 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.

    1998-12-14

    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.

  6. 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.

    1997-11-01

    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.

  7. 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

    2010-10-01

    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.

  8. Double beta decay: experiments and theory review

    E-Print Network [OSTI]

    A. Nucciotti

    2007-07-28

    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.

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

    E-Print Network [OSTI]

    B. Pritychenko

    2015-03-11

    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.

  10. Probing surface distribution of $\\alpha$-cluster in $^{20}$Ne via $\\alpha$-transfer reaction

    E-Print Network [OSTI]

    Fukui, Tokuro; Suhara, Tadahiro; Kanada-En'yo, Yoshiko; Ogata, Kazuyuki

    2015-01-01

    Direct evidence of the $\\alpha$-cluster development in bound states has not been obtained yet although a number of experimental studies were carried out to extract the information of the clustering. In particular in conventional analyses of $\\alpha$-transfer reactions, there exist a few significant problems on reaction models, which are insufficient to qualitatively discuss the cluster structure. We aim to verify the development of the $\\alpha$-cluster structure from observables. As the first application, it is argued to extract the spatial information of the cluster structure of the $^{20}$Ne nucleus in its ground state through the cross section of the $\\alpha$-transfer reaction $^{16}$O($^6$Li,~$d$)$^{20}$Ne. For the analysis of the transfer reaction, we work with the coupled-channels Born approximation (CCBA) approach, in which the breakup effect of $^6$Li is explicitly taken into account by means of the continuum-discretized coupled-channels method (CDCC) based on the three-body $\\alpha + d + {}^{16}$O mo...

  11. Polarity of annealing and structural analysis of the RNase H resistant alpha-5'-d(TACACA). beta-5'-r(AUGUGU) hybrid determined by high-field sup 1 H, sup 13 C, and sup 31 P NMR analysis

    SciTech Connect (OSTI)

    Gmeiner, W.H.; Rao, K.E.; Rayner, B.; Vasseur, J.J.; Morvan, F.; Imbach, J.L.; Lown, J.W. )

    1990-11-13

    The novel hybrid duplex alpha-5'-d(TACACA)-3'.beta-5'-r(AUGUGU)-3' was analyzed extensively by 1D and 2D NMR methods. Two forms of the duplex exist in about an 80:20 ratio. Analysis of the exchangeable imino protons of the major component revealed that three AU and one AT base pair are present in addition to two GC base pairs, confirming that the duplex anneals in parallel orientation. The presence of the AT base pair, which can only be accounted for by a parallel duplex, was confirmed by a selective INEPT experiment, which correlated the thymidine imino proton to its C5 carbon. The lesser antiparallel form could be detected by exchangeable and nonexchangeable proton resonances in both strands. An exchange peak was observed in the NOESY spectrum for the thymidine methyl group resonance in both the predominant and lesser conformations, indicating the lifetime of the individual structures was on the millisecond time scale. The nonexchangeable protons of the predominant duplex were assigned by standard methods. The sugar pucker of the ribonucleosides was determined to be of the S type by a pseudorotation analysis according to Altona, with the J-couplings measured from the multiplet components of the phase-sensitive COSY experiment. The NOE pattern observed for the alpha-deoxynucleosides also suggested an S-type sugar pucker. The adoption of an S-type sugar pucker for both strands indicates that, in contrast to RNA.DNA duplexes formed exclusively from beta-nucleotides, the alpha-DNA.beta-RNA duplex may form a B-type helix. The 31P resonances of the alpha and beta strands have very different chemical shifts in the hybrid duplex and the difference persists above the helix melting temperature, indicating an intrinsic difference in 31P chemical shift for nucleotides differing only in the configuration about the glycosidic bond.

  12. The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studies

    E-Print Network [OSTI]

    A. Ornelas; G. G. Kiss; P. Mohr; D. Galaviz; Zs. Fülöp; Gy. Gyürky; Z. Máté; T. Rauscher; E. Somorjai; K. Sonnabend; A. Zilges

    2015-04-29

    Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new high precision angular distributions, together with the data available from the literature were used to study the energy dependence of the locally optimized {\\alpha}+nucleus optical potential in a wide energy region ranging from E_Lab = 27.0 MeV down to 16.1 MeV. The potentials under study are a basic prerequisite for the prediction of alpha-induced reaction cross sections and thus, for the calculation of stellar reaction rates used for the astrophysical gamma process. Therefore, statistical model predictions using as input the optical potentials discussed in the present work are compared to the available 106Cd + alpha cross section data.

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

    E-Print Network [OSTI]

    Hsiang-nan Li; Satoshi Mishima

    2007-03-02

    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.

  14. Decay estimates for One-dimensional wave equations with inverse power potentials

    E-Print Network [OSTI]

    O. Costin; M. Huang

    2014-10-23

    We study the one-dimensional wave equation with an inverse power potential that equals $const.x^{-m}$ for large $|x|$ where $m$ is any positive integer greater than or equal to 3. We show that the solution decays pointwise like $t^{-m}$ for large $t$, which is consistent with existing mathematical and physical literature under slightly different assumptions (see e.g. Bizon, Chmaj, and Rostworowski, 2007; Donninger and Schlag, 2010; Schlag, 2007). Our results can be generalized to potentials consisting of a finite sum of inverse powers, the largest of which being $const.x^{-\\alpha}$ where $\\alpha>2$ is a real number, as well as potentials of the form $const.x^{-m}+O(x^{-m-\\delta_1})$ with $\\delta_1>3$.

  15. High-resolution ion pulse ionization chamber with air filling for the Rn-222 decays detection

    E-Print Network [OSTI]

    Gavrilyuk, Yu M; Gezhaev, A M; Etezov, R A; Kazalov, V V; Kuzminov, V V; Panasenko, S I; Ratkevich, S S; Tekueva, D A; Yakimenko, S P

    2015-01-01

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register alpha-particles from the $^{222}$Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV alpha-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented.

  16. The splitted laser beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma

    SciTech Connect (OSTI)

    Xia Xiongping; Yi Lin; Xu Bin; Lu Jianduo

    2011-10-15

    The splitted beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma is investigated. Based on Wentzel-Kramers-Brillouin (WKB) approximation and paraxial/nonparaxial ray theory, simulation results show that the steady beam width and single beam filamentation along the propagation distance in paraxial case is due to the influence of ponderomotive nonlinearity. In nonparaxial case, the influence of the off-axial of {alpha}{sub 00} and {alpha}{sub 02} (the departure of the beam from the Gaussian nature) and S{sub 02} (the departure from the spherical nature) results in more complicated ponderomotive nonlinearity and changing of the channel density and refractive index, which led to the formation of two/three splitted beam filamentation and the self-distortion of beam width. In addition, influence of several parameters on two/three splitted beam filamentation is discussed.

  17. Production of A=6,7 Nuclides in the Alpha + Alpha Reaction and Cosmic Ray Nucleosynthesis

    E-Print Network [OSTI]

    David J. Mercer; Sam M. Austin; J. A. Brown; S. A. Danczyk; S. E. Hirzebruck; J. H. Kelley; T. Suomijarvi; D. A. Roberts; T. P Walker

    2001-04-03

    Cross sections for production of 6He, 6Li, 7Li, and 7Be in the alpha+alpha reaction were measured at bombarding energies of 159.3, 279.6, and 619.8 MeV, and are found to decrease rapidly with increasing energy. These cross sections are essential for the calculation of the rate of nucleosynthesis of the lithium isotopes in the cosmic rays and thereby play a key role in our understanding of the synthesis of Li, Be, and B. The results for 6Li differ significantly from the tabulated values commonly used in cosmic-ray production calculations and lead to lower production of 6Li.

  18. FDCSUSYDecay: A MSSM Decay package

    E-Print Network [OSTI]

    Wei Qi; Jian-Xiong Wang

    2006-12-01

    FDCSUSYDecay is a FORTRAN program package generated by FDC (Feynman Diagram Calculation) system fully automatically. It is dedicated to calculate at tree-level all the possible 2-body decays of SUSY and Higgs particles in the Minimal Supersymmetric extension of the Standard Model (MSSM). The format of its output files complies with SUSY Les Houches Accord and can be easily imported by other packages.

  19. Speeding-up Thorium decay

    E-Print Network [OSTI]

    F. Cardone; R. Mignani; A. Petrucci

    2007-10-26

    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.

  20. 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)

    2014-05-02

    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.

  1. Supersymmetric QCD corrections to the top quark decay of a heavy charged higgs boson

    E-Print Network [OSTI]

    Ricardo A. Jimenez; Joan Sola

    1996-10-24

    The supersymmetric QCD corrections to the hadronic width of a heavy charged Higgs boson, basically dominated by the top-quark decay mode $H^{+}\\rightarrow t \\bar{b}$, are evaluated at ${\\cal O}(\\alpha_s)$ within the MSSM and compared with the standard QCD corrections. The study of such quantum effects, which turn out to be rather large, is essential to understand the hypothetical supersymmetric nature of a heavy charged Higgs boson potentially produced in the near future at the Tevatron and/or at the LHC.

  2. Background due to stored electrons following nuclear decays in the KATRIN spectrometers and its impact on the neutrino mass sensitivity

    E-Print Network [OSTI]

    Mertens, S; Fraenkle, F M; Furse, D; Glueck, F; Goerhardt, S; Hoetzel, M; Kaefer, W; Leiber, B; Thuemmler, T; Wandkowsky, N; Wolf, J

    2012-01-01

    The KATRIN experiment is designed to measure the absolute neutrino mass scale with a sensitivity of 200 meV at 90% C.L. by high resolution tritium beta-spectroscopy. A low background level of 10 mHz at the beta-decay endpoint is required in order to achieve the design sensitivity. In this paper we discuss a novel background source arising from magnetically trapped keV electrons in electrostatic retarding spectrometers. The main sources of these electrons are alpha-decays of the radon isotopes (219,220)Rn as well as beta-decays of tritium in the volume of the spectrometers. We characterize the expected background signal by extensive MC simulations and investigate the impact on the KATRIN neutrino mass sensitivity. From these results we refine design parameters for the spectrometer vacuum system and propose active background reduction methods to meet the stringent design limits for the overall background rate.

  3. A correlation between intrinsic brightness and average decay rate of Swift UVOT GRB optical/UV light curves

    E-Print Network [OSTI]

    Oates, S R; De Pasquale, M; Schady, P; Breeveld, A A; Holland, S T; Kuin, N P M; Marshall, F E

    2012-01-01

    We examine a sample of 48 Swift/UVOT long Gamma-ray Burst light curves and find a correlation between the logarithmic luminosity at 200s and average decay rate determined from 200s onwards, with a Spearman rank coefficient of -0.58 at a significance of 99.998% (4.2 sigma). We discuss the causes of the log L_200s - alpha_>200s correlation, finding it to be an intrinsic property of long GRBs, and not resulting from the selection criteria. We find two ways to produce the correlation. One possibility is that there is some property of the central engine, outflow or external medium that affects the rate of energy release so that the bright afterglows release their energy more quickly and decay faster than the fainter afterglows. Alternatively, the correlation may be produced by variation of the observers viewing angle, with observers at large viewing angles observing fainter and slower decaying light curves.

  4. 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)

    2013-02-20

    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.

  5. Performance checks with the Alpha Sentry CAM

    SciTech Connect (OSTI)

    Rodgers, J.C.

    1994-08-01

    Before a CAM is put into service, it must be calibrated. The flow meter and detector must be calibrated with an external flow meter to provide accurate flow data, and the detector must be calibrated to produce accurate DPM data. Both flow and DPM data enter into the calculation of the Derived Air Concentration exposure (DAC-hr) by the CAM software. The focus of this report is on methods for checking that the DAC-hr alarm functionality has been properly calibrated and available in installed CAM instruments. The process begins with detector calibration. In order to calibrate the detector, the Alpha Sentry CAM is placed in an off-line calibration mode and detector efficiency calibration is selected. The user is prompted to enter the calibration source DPM and place the source in the CAM head. Upon latching the filter door with the source in place, a count is automatically initiated and completed. From the count data and the user entered DPM data, an efficiency is determined in the Alpha Sentry Manager (ASM) and stored in non-volatile memory in the CAM head electronics. This source is typically a plated {sup 239}Pu or {sup 241}Am source diffused into a stainless steel planchet.

  6. GHRS Observations of the Lyman alpha Forest

    E-Print Network [OSTI]

    Simon L. Morris

    1996-10-28

    I review the results obtained using the GHRS on low redshift Lyman alpha absorbers. Until the advent of HST and the GHRS, the existence of such absorbers was doubted. The confirmation of their existence, in one of the first GHRS GTO team results to be published, must rank as one of the HSTs most interesting results. The GHRS resolution allows us to probe equivalent widths well below those detectable with the FOS, and has led to a number of interesting new questions. One example is the apparent disagreement between the GHRS result that there are many Lyman alpha absorbers which are not associated with luminous galaxies, and FOS studies which suggest that all such absorbers have a nearby galaxy causing them. This almost certainly shows that the equivalent width (or column density) range reachable by the GHRS includes gas from a wide range of causes, and not only the halos of luminous galaxies. With these data, we are seeing the debris left over from Galaxy formation, material flung out from galaxy interactions and starbursts, and also diffuse halo material at the outer edges of normal galaxies.

  7. MFTF-. cap alpha. + T progress report

    SciTech Connect (OSTI)

    Nelson, W.D.

    1985-04-01

    Early in FY 1983, several upgrades of the Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory (LLNL) were proposed to the fusion community. The one most favorably received was designated MFTF-..cap alpha..+T. The engineering design of this device, guided by LLNL, has been a principal activity of the Fusion Engineering Design Center during FY 1983. This interim progress report represents a snapshot of the device design, which was begun in FY 1983 and will continue for several years. The report is organized as a complete design description. Because it is an interim report, some parts are incomplete; they will be supplied as the design study proceeds. As described in this report, MFTF-..cap alpha..+T uses existing facilities, many MFTF-B components, and a number of innovations to improve on the physics parameters of MFTF-B. It burns deuterium-tritium and has a central-cell Q of 2, a wall loading GAMMA/sub n/ of 2 MW/m/sup 2/ (with a central-cell insert module), and an availability of 10%. The machine is fully shielded, allows hands-on maintenance of components outside the vacuum vessel 24 h after shutdown, and has provisions for repair of all operating components.

  8. Lyman alpha Absorption Systems and the Intergalactic Medium

    E-Print Network [OSTI]

    George Efstathiou; Joop Schaye; Tom Theuns

    2000-04-10

    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.

  9. New features in the stability and fission decay of superheavy Thorium isotopes

    E-Print Network [OSTI]

    L. Satpathy; S. K. Patra; R. K. Choudhury

    2006-04-12

    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.

  10. Two- and three-alpha systems with nonlocal potential

    E-Print Network [OSTI]

    Z. Papp; S. Moszkowski

    2008-03-26

    Two body data alone cannot determine the potential uniquely, one needs three-body data as well. A method is presented here which simultaneously fits local or nonlocal potentials to two-body and three-body observables. The interaction of composite particles, due to the Pauli effect and the indistinguishability of the constituent particles, is genuinely nonlocal. As an example, we use a Pauli-correct nonlocal fish-bone type optical model for the $\\alpha-\\alpha$ potential and derive the fitting parameters such that it reproduces the two-$\\alpha$ and three-$\\alpha$ experimental data.

  11. Penguin pollution estimates relevant for phi_2/alpha extraction

    E-Print Network [OSTI]

    Jure Zupan

    2007-08-16

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

  12. Alpha-particle optical potential proofs at astrophysically relevant energies

    E-Print Network [OSTI]

    M. Avrigeanu; V. Avrigeanu

    2008-11-01

    $(\\alpha,\\gamma)$ and $(\\alpha$,n) reaction cross sections recently measured close to the reaction thresholds are rather well described by a previously developed regional optical potential. Thus, particular features of the $\\alpha$-particle optical potential at energies below the Coulomb barrier, besides parameters describing $\\alpha$-particle elastic scattering at higher energies are confirmed. Additional limitations of similar statistical model calculations for minor reaction channels are shown to be most likely due to an overlooked process or critical values of statistical model parameters around closed nuclear shells.

  13. Decays of Fourth Generation Bound States

    E-Print Network [OSTI]

    V. F. Dmitriev; V. V. Flambaum

    2012-08-28

    We consider the decay modes of the heavy $q^\\prime\\bar{q^\\prime}$ bound states originating from Higgs boson exchange between quark -- anti-quark pair. In case of a small coupling between the fourth and lower generation the main decay mode is $q^\\prime\\bar{q^\\prime}$ annihilation. We show that for a vector state the dominant decay modes are Higgs-gamma and Higgs-Z decays, while for a pseudoscalar state the strong two-gluon decay mode dominates. The bound states are very narrow. The ratio of the total width to the binding energy is less than 1% if we are not extremely close to the critical quark mass where the binding energy is very small. The discussed decay modes exist for any fermion-antifermion bound states including heavy leptons and heavy neutrinos if their masses are high enough to form a bound state due to attractive Higgs boson exchange potential.

  14. Power Spectrum Analyses of Nuclear Decay Rates

    E-Print Network [OSTI]

    Javorsek, D; Lasenby, R N; Lasenby, A N; Buncher, J B; Fischbach, E; Gruenwald, J T; Hoft, A W; Horan, T J; Jenkins, J H; Kerford, J L; Lee, R H; Longman, A; Mattes, J J; Morreale, B L; Morris, D B; Mudry, R N; Newport, J R; O'Keefe, D; Petrelli, M A; Silver, M A; Stewart, C A; Terry, B; 10.1016/j.astropartphys.2010.06.011

    2010-01-01

    We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are n...

  15. Electroweak penguin decays at LHCb

    E-Print Network [OSTI]

    Thomas Blake

    2011-09-29

    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 $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$.

  16. Neutrinoless double beta decay experiments

    E-Print Network [OSTI]

    K. Zuber

    2006-10-04

    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.

  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.

    1984-01-01

    be- tween 62 and 100 MeV, several experimental and theoreti- cal investigations have been performed on this reaction. Recently, Nagatani et al. studied the same reaction at the higher incident energy of E(' 0)=145 MeV and observed prominent... structures on an underlying continuum back- ground in the range of E?( Mg) =30?56 MeV. The ob- served structures were thought to be the result of a direct transfer reaction to the high-spin members of the ' C+ ' C nuclear molecular resonances...

  18. Neutrinoless Double Beta Decay and CP Violation

    E-Print Network [OSTI]

    Patrick J. O'Donnell; Utpal Sarkar

    1993-05-27

    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).

  19. 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...

  20. Displacement Echoes: Classical Decay and Quantum Freeze

    E-Print Network [OSTI]

    Cyril Petitjean; Diego V. Bevilaqua; Eric J. Heller; Philippe Jacquod

    2007-04-23

    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.

  1. Neutrinoless Double Beta Decay: Present and Future

    E-Print Network [OSTI]

    Oliviero Cremonesi

    2002-10-04

    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\

  2. Tensor mesons produced in tau lepton decays

    SciTech Connect (OSTI)

    Lopez Castro, G.; Munoz, J. H.

    2011-05-01

    Light tensor mesons (T=a{sub 2}, f{sub 2} and K{sub 2}*) can be produced in decays of {tau} leptons. In this paper we compute the branching ratios of {tau}{yields}T{pi}{nu} decays by assuming the dominance of intermediate virtual states to model the form factors involved in the relevant hadronic matrix elements. The exclusive f{sub 2}(1270){pi}{sup -} decay mode turns out to have the largest branching ratio, of O(10{sup -4}). Our results indicate that the contribution of tensor meson intermediate states to the three-pseudoscalar channels of {tau} decays are rather small.

  3. Review of double beta decay experiments

    E-Print Network [OSTI]

    A. S. Barabash

    2014-03-12

    The brief review of current experiments on search and studying of double beta decay processes is done. Best present limits on $\\langle m_{\

  4. Neutrinoless Double Beta Decay and Neutrino Masses

    E-Print Network [OSTI]

    Michael Duerr

    2012-06-04

    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.

  5. 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)

    2007-04-20

    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.

  6. Nuclear beta-decay measurements and |Vud|

    E-Print Network [OSTI]

    Dan Melconian

    2011-08-11

    Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.

  7. Direct CP violation in B decays

    E-Print Network [OSTI]

    M. Kreps

    2008-07-01

    We review recent experimental results on direct CP violation. The hot topic is a measurement in charmless two-body decays of B0, B+. In connection to this the first analogous measurements in Bs0 and Lambda_b0 decays are now available. Furthermore first evidence for direct CP violation in B+ decays is obtained from Dalitz plot analyzes of the K+pi-pi+ final state at B-factories. The last group of discussed results probes the b -> c\\bar{c}d transition in attempt to resolve the discrepancy between Belle and BABAR experiments in CP violation in the B0 -> D+D- decays.

  8. Constraining |V(td)|/|V(ts)| Using Radiative Penguin B -> V(K*/rho/omega)gamma Decays

    SciTech Connect (OSTI)

    Tan, Ping; /Wisconsin U., Madison

    2006-03-08

    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}|.

  9. Measurement of branching fraction ratios and CP asymmetries in B →D0 CPK decays with the BABAR detector

    SciTech Connect (OSTI)

    Marchiori, Giovanni; /Pisa U.

    2010-05-05

    The primary goals of the BABAR experiment are the detection of CP violation (CPV) in the B meson system, the precise measurement of some of the elements of the CKM matrix and the measurement of the rates of rare B meson decays. At present, BABAR has achieved major successes: (1) the discovery, in neutral B decays, of direct and mixing-induced CP violation; (2) accurate measurements of the magnitudes of the CKM matrix elements |V{sub cb}| and |V{sub ub}|; (3) a precise measurement of the CKM parameter {beta} {triple_bond} arg[- V{sub cd}V*{sub cb}/V{sub td}V*{sub tb}]; (4) a first measurement of the CKM parameters {alpha} {triple_bond} arg[- V{sub td}V*{sub tb}/V{sub ud}V*{sub ub}], {gamma} {triple_bond} arg[- V{sub ud}V*{sub ub}/V{sub cd}V*{sub cb}]; and (5) the observation of several rare B decays and the discovery of new particles (in the charmed and charmonium mesons spectroscopy). However, the physics program of BABAR is not yet complete. Two of the key elements of this program that still need to be achieved are: (1) the observation of direct CP violation in charged B decays, which would constitute the first evidence of direct CPV in a charged meson decay; and (2) the precise measurement of {alpha} and {gamma}, which are necessary ingredients for a stringent test of the Standard Model predictions in the quark electroweak sector. A possibility for the discovery of direct CP violation in charged B decays would be the observation of a non-vanishing rate asymmetry in the Cabibbo-suppressed decay B{sup -} {yields} D{sup 0} K{sup -}, with the D{sup 0} decaying to either a CP-even or a CP-odd eigenstate. This class of decays can also provide theoretically-clean information on {gamma}.

  10. Lyman Alpha Absorption in The Cosmic Web

    E-Print Network [OSTI]

    J. Richard Bond; James W. Wadsley

    1997-10-10

    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.

  11. Synthesis of alpha-amino acids

    DOE Patents [OSTI]

    Davis, J.W. Jr.

    1983-01-25

    A method is described for synthesizing alpha amino acids proceeding through novel intermediates of the formulas: R[sub 1]R[sub 2]C(OSOCl)CN, R[sub 1]R[sub 2]C(Cl)CN and [R[sub 1]R[sub 2]C(CN)O][sub 2]SO wherein R[sub 1] and R[sub 2] are each selected from hydrogen monovalent substituted and unsubstituted hydrocarbon radicals of 1 to 10 carbon atoms. The use of these intermediates allows the synthesis steps to be exothermic and results in an overall synthesis method which is faster than the synthesis methods of the prior art. No Drawings

  12. Constraining Reionization with Lyman Alpha Emitting Galaxies

    E-Print Network [OSTI]

    Dijkstra, Mark

    2015-01-01

    Neutral diffuse intergalactic gas that existed during the Epoch of Reionization (EoR) suppresses Lyman Alpha (Lya) flux emitted by background galaxies. In this chapter I summarise the increasing observational support for the claim that Lya photons emitted by galaxies at z>6 are suppressed by intervening HI gas. I describe key physical processes that affect Lya transfer during the EoR. I argue that in spite of the uncertainties associated with this complex multiscale problem, the data on Lya emitting galaxies at z=0-6 strongly suggests that the observed reduction in Lya flux from galaxies at z>6 is due to additional intervening HI gas. The main question is what fraction of this additional HI gas is in the diffuse neutral IGM. I summarise how future surveys on existing and upcoming instruments are expected to reduce existing observational uncertainties enormously. With these improved data we will likely be able to nail down reionization with Lya emitting galaxies.

  13. Signatures of reionization on Lyman alpha emitters

    E-Print Network [OSTI]

    Pratika Dayal; Andrea Ferrara; Simona Gallerani

    2008-07-23

    We use a semi-analytic model of Lyman alpha emitters (LAEs) to constrain the reionization history. By considering two physically motivated scenarios in which reionization ends either early (ERM, z_i ~ 7) or late (LRM, z_i ~ 6), we fix the global value of the IGM neutral fraction (e.g. chi_{HI}=3 times 10^{-4}, 0.15 at z=6.56 for the ERM and LRM, respectively) leaving only the star formation efficiency and the effective escape fraction of Lya photons as free parameters. The ERM fits the observed LAE luminosity function (LF) at z=5.7 and 6.56 requiring no redshift evolution or mass dependence of the star formation efficiency, and LAE star formation rates (SFR) of 3-103 solar masses/year, contributing approximately 8% of the cosmic SFR density at z=5.7. The LRM requires a physically uncomfortable drop of approximately 4.5 times in the SFR of the emitters from z=6.5 to 5.7. Thus, the data seem to imply that the Universe was already highly ionized at z=6.56. The mass-dependent Lya transmissivity is between 0.36-0.51 (ERM) and less than 0.26 (LRM) at z=6.56. The LF data at z=4.5 imply an extra Lya line damping factor of approximately 0.25 possibly due to dust; the presence of a (clumpy) dust component with E(B-V) ~ 0.28 is also required to reproduce the observed large Lya equivalent widths at the same redshift. Additional useful information can be extracted from the line profile (weighted) skewness, found to be S_W=10-17 Angstrom for the two reionization models, which shows an interesting L_alpha-chi_{HI} anti-correlation, holding under the model assumptions. The shortcomings of the model and strategies to overcome them are discussed.

  14. Method for using a yeast alpha-amylase promoter

    DOE Patents [OSTI]

    Gao, Johnway (Richland, WA); Skeen, Rodney S. (Pendleton, OR); Hooker, Brian S. (Kennewick, WA); Anderson, Daniel B. (Pasco, WA)

    2003-04-22

    The present invention provides the promoter clone discovery of an alpha-amylase gene of a starch utilizing yeast strain Schwanniomyces castellii. The isolated alpha-amylase promoter is an inducible promoter, which can regulate strong gene expression in starch culture medium.

  15. Generating long streams of $1/f^alpha$ noise

    E-Print Network [OSTI]

    S. Plaszczynski

    2008-07-09

    We review existing methods for generating long streams of 1/f^alpha noise ($0logistic maps, we give hints on how to design generators with $\\alpha>2$. The software is available from http://planck.lal.in2p3.fr/article.php3?id\\_article=8

  16. I: Maxwell's equations with Ohm's law. II: Polynomial energy decay. Polynomial decay rate

    E-Print Network [OSTI]

    Phung, Kim-dang.- Le Laboratoire de Mathématiques

    I: Maxwell's equations with Ohm's law. II: Polynomial energy decay. Polynomial decay rate: Maxwell's equations with Ohm's law. II: Polynomial energy decay. Maxwell's equation with Ohm's law Let@ = 0 2 L1 ( ) and 0 take "o = o = 1 #12;I: Maxwell's equations with Ohm's law. II: Polynomial energy

  17. 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

    2012-12-12

    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.

  18. 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)

    2009-04-02

    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.

  19. Weak decays of 4He-Lambda

    E-Print Network [OSTI]

    J. D. Parker; M. J. Athanas; P. D. Barnes; S. Bart; B. Bassalleck; R. Chrien; G. Diebold; G. B. Franklin; K. Johnston; P. Pile; B. Quinn; F. Rozon; R. Sawafta; R. A. Schumacher; R. Stearns; I. Sukaton; R. Sutter; J. J. Szymanski; V. J. Zeps

    2007-09-13

    We measured the lifetime and the mesonic and non-mesonic decay rates of the 4He-Lambda hypernucleus. The hypernuclei were created using a 750 MeV/c momentum K- beam on a liquid 4He target by the reaction 4He(K-,pi-)4He-Lambda. The 4He-Lambda lifetime was directly measured using protons from Lambda p -> n p non-mesonic decay (also referred to as proton-stimulated decay) and was found to have a value of tau = 245 +/- 24 ps. The mesonic decay rates were determined from the observed numbers of pi-'s and pi0's as Gamma_pi-/Gamma_tot = 0.270 +/- 0.024 and Gamma_pi0/Gamma_tot = 0.564 +/- 0.036, respectively, and the values of the proton- and neutron-stimulated decay rates were extracted as Gamma_p/Gamma_tot = 0.169 +/- 0.019 and Gamma_n/Gamma_tot <= 0.032 (95% CL), respectively. The effects of final-state interactions and possible 3-body Lambda N N decay contributions were studied in the context of a simple model of nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and were used in the determination of the non-mesonic branching fractions. The implications of the results of this analysis were considered for the empirical Delta I = 1/2 rule and the decay rates of the 4H-Lambda hypernucleus.

  20. Spectroscopy and decays of charm and bottom

    SciTech Connect (OSTI)

    Butler, J.N.

    1997-10-01

    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.

  1. Neutrinoless double beta decay and neutrino physics

    E-Print Network [OSTI]

    Werner Rodejohann

    2012-08-20

    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.

  2. Higgs boson decay to Ali Abbasabadi

    E-Print Network [OSTI]

    Repko, Wayne

    Higgs boson decay to #22;#22;#22; Ali Abbasabadi Department of Physical Sciences, Ferris State, East Lansing, Michigan 48824, USA (April 17, 2000) The Higgs boson decay, H ! #22;#22;#22; , is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 Ge

  3. Testing the Standard Model with Kaon Decays

    E-Print Network [OSTI]

    Matthew Moulson

    2012-09-15

    During the last few years, new experimental and theoretical results have allowed ever more stringent tests of the Standard Model to be performed using kaon decays. This overview of recent progress includes an updated evaluation of the CKM matrix element Vus. Tests of CKM unitarity and gauge universality and lepton universality tests with Kl2 and Kl3 decays are discussed.

  4. 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)

    2005-11-01

    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.

  5. 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 ...

  6. Strong effects in weak nonleptonic decays

    SciTech Connect (OSTI)

    Wise, M.B.

    1980-04-01

    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.

  7. Lepton flavor violation in Higgs boson decays under the rare...

    Office of Scientific and Technical Information (OSTI)

    Lepton flavor violation in Higgs boson decays under the rare tau decay results Citation Details In-Document Search Title: Lepton flavor violation in Higgs boson decays under the...

  8. Neutrinoless Double Beta Decay in Light of SNO Salt Data

    E-Print Network [OSTI]

    Murayama, Hitoshi

    2009-01-01

    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

  9. Antihydrogen Trapped in the ALPHA Experiment

    ScienceCinema (OSTI)

    None

    2011-04-25

    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  

  10. ALPHA SPECTROSCOPIC TECHNIQUES FOR FIELD MEASUREMENT OF RADON DAUGHTERS

    E-Print Network [OSTI]

    Nazaroff, M.W.

    2010-01-01

    ventilation with heat recovery for controlling radonand radon-daughter concentrations in residences, Lawrencealpha energy concentration of radon decay products, Lawrence

  11. Thick-Target Neutron Yield from the 19F(alpha,n) Reaction

    E-Print Network [OSTI]

    E. B. Norman; T. E. Chupp; K. T. Lesko; G. L. Woodruff; P. J. Grant

    2015-01-10

    Thick-target neutron yields from the 19F(alpha,n) reaction are reported for E(alpha) = 3.5 - 10.0 MeV.

  12. Proton decay matrix elements with domain-wall fermions

    E-Print Network [OSTI]

    Y. Aoki; C. Dawson; J. Noaki; A. Soni

    2006-09-18

    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.

  13. 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)

    2008-11-01

    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.

  14. 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...

  15. Photoproduction and Decay of Light Mesons in CLAS

    SciTech Connect (OSTI)

    Amaryan, Moskov Jamalovich

    2013-08-01

    We present preliminary experimental results on photoproduction and decay of light mesons measured with CLAS setup at JLAB . This include Dalitz decay of pseudoscalar and vector mesons, radiative decay of pseudoscalar mesons as well hadronic decays of pseudoscalar and vector mesons. The collected high statistics in some of decay channels exceeds the world data by an order of magnitude and some other decay modes are observed for the first time. It is shown how the CLAS data will improve the world data on transition form factors of light mesons, Dalitz plot analyses, branching ratios of rare decay modes and other fundamental properties potentially accessible through the light meson decays.

  16. SciTech Connect: "neutrinoless double beta decay"

    Office of Scientific and Technical Information (OSTI)

    neutrinoless double beta decay" Find + Advanced Search Term Search Semantic Search Advanced Search All Fields: "neutrinoless double beta decay" Semantic Semantic Term Title:...

  17. 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

    2008-05-27

    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.

  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)

    2002-01-01

    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. Leptonic Decays of Charged Pseudoscalar Mesons - 2015

    E-Print Network [OSTI]

    Rosner, Jonathan L; Van de Water, Ruth S

    2015-01-01

    We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be use...

  20. 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.

    2008-03-07

    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.

  1. Linear Transformation Method for Multinuclide Decay Calculation

    SciTech Connect (OSTI)

    Ding Yuan

    2010-12-29

    A linear transformation method for generic multinuclide decay calculations is presented together with its properties and implications. The method takes advantage of the linear form of the decay solution N(t) = F(t)N{sub 0}, where N(t) is a column vector that represents the numbers of atoms of the radioactive nuclides in the decay chain, N{sub 0} is the initial value vector of N(t), and F(t) is a lower triangular matrix whose time-dependent elements are independent of the initial values of the system.

  2. Closed strings from decaying D-branes

    E-Print Network [OSTI]

    Neil Lambert; Hong Liu; Juan Maldacena

    2007-02-05

    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.

  3. The mass spectra and decay properties of dimesonic states, using the Hellmann potential

    E-Print Network [OSTI]

    Rai, Ajay Kumar

    2015-01-01

    Mass spectra of the dimesonic (meson - antimeson) molecular states are computed using the Hellmann potential in variational approach, which consists of relativistic correction to kinetic energy term as well as to the potential energy term. To the study of molecular bound state system, the Hellmann potential of the form $V(r)=-\\frac{\\alpha_{s}}{r} + \\frac{B e^{-Cr}}{r}$ is being used. The one pion exchange potential (OPEP) is also incorporated in the mass calculation. The digamma decay width and decay width of the dimesonic system are evaluated using the wave function. The experimental states such as $f_{0}(980)$, $b_{1}(1235)$, $h_{1}(1380)$, $a_{0}(1450)$, $f_{0}(1500)$, $f_{2}'(1525)$, $f_{2}(15 65)$, $f_{1}(1595)$, $a_{2}(1700)$, $f_{0}(1710)$, $f_{2}(1810)$ are compared with dimesonic states. Many of these states (mass- es and their decay properties) are close to our theoretical predictions.

  4. The mass spectra and decay properties of dimesonic states, using the Hellmann potential

    E-Print Network [OSTI]

    Ajay Kumar Rai; D. P. Rathaud

    2015-09-22

    Mass spectra of the dimesonic (meson-antimeson) molecular states are computed using the Hellmann potential in variational approach, which consists of relativistic correction to kinetic energy term as well as to the potential energy term. For the study of molecular bound state system, the Hellmann potential of the form $V(r)=-\\frac{\\alpha_{s}}{r} + \\frac{B e^{-Cr}}{r}$ is being used. The one pion exchange potential (OPEP) is also incorporated in the mass calculation. The digamma decay width and decay width of the dimesonic system are evaluated using the wave function. The experimental states such as $f_{0}(980)$, $b_{1}(1235)$, $h_{1}(1380)$, $a_{0}(1450)$, $f_{0}(1500)$, $f_{2}'(1525)$,$f_{2}(1565)$, $h_{1}(1595)$, $a_{2}(1700)$, $f_{0}(1710)$, $f_{2}(1810)$ are compared with dimesonic states. Many of these states (masses and their decay properties) are close to our theoretical predictions.

  5. The mass spectra and decay properties of dimesonic states, using the Hellmann potential

    E-Print Network [OSTI]

    Ajay Kumar Rai; D. P. Rathaud

    2015-07-06

    Mass spectra of the dimesonic (meson - antimeson) molecular states are computed using the Hellmann potential in variational approach, which consists of relativistic correction to kinetic energy term as well as to the potential energy term. To the study of molecular bound state system, the Hellmann potential of the form $V(r)=-\\frac{\\alpha_{s}}{r} + \\frac{B e^{-Cr}}{r}$ is being used. The one pion exchange potential (OPEP) is also incorporated in the mass calculation. The digamma decay width and decay width of the dimesonic system are evaluated using the wave function. The experimental states such as $f_{0}(980)$, $b_{1}(1235)$, $h_{1}(1380)$, $a_{0}(1450)$, $f_{0}(1500)$, $f_{2}'(1525)$, $f_{2}(15 65)$, $f_{1}(1595)$, $a_{2}(1700)$, $f_{0}(1710)$, $f_{2}(1810)$ are compared with dimesonic states. Many of these states (mass- es and their decay properties) are close to our theoretical predictions.

  6. 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.; Ashwood, N. I.; Curtis, N.; Malcolm, J.; Munoz-Britton, T.; Price, D.; Wheldon, C.; Achouri, N. L.; Demaret, P.; Bardayan, Daniel W; Pain, Steven D; Brown, S.; Catford, W.; Harlin, Christopher W; Thomas, J. S.; Wilson, G.; Chipps, K.; Milin, M.; Raabe, R.; Soic, N.

    2012-01-01

    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.

  7. Evaluation of probes used to detect alpha radiation 

    E-Print Network [OSTI]

    Sackett, Gregory Duane

    1995-01-01

    difficult to detect with survey meters. In response to these concerns several probes have been designed with an increased sensitivity to alpha radiation, combining larger sensitive surface areas with very thin windows to increase detector efficiency. Two...

  8. The Gamma Ray Detection Capabilities of the Alpha Magnetic Spectrometer

    E-Print Network [OSTI]

    R. Battiston; M. Biasini; E. Fiandrini; J. Petrakis; M. H. Salamon

    1999-09-30

    The modeled performance of the Alpha Magnetic Spectrometer (AMS) as a high energy (0.3 to 100 GeV) gamma-ray detector is described, and its gamma ray astrophysics objectives are discussed.

  9. Energetics of [alpha]-helix formation in peptides and proteins

    E-Print Network [OSTI]

    Schubert, Christian Reinhold

    2009-01-01

    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 ...

  10. Standoff alpha radiation detection via excited state absorption of air

    E-Print Network [OSTI]

    Yao, Jimmy; Brenizer, Jack; Hui, Rongqing; Yin, Stuart (Shizhuo)

    2013-06-24

    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...

  11. Asteroseismology and calibration of alpha Cen binary system

    E-Print Network [OSTI]

    Thévenin, F; Morel, P; Berthomieu, G; Bouchy, F; Carrier, F

    2002-01-01

    Using the oscillation frequencies of alpha Cen A recently discovered by Bouchy & Carrier, the available astrometric, photometric and spectroscopic data, we tried to improve the calibration of the visual binary system alpha Cen. With the revisited masses of Pourbaix et al. (2002) we do not succeed to obtain a solution satisfying all the seismic observational constraints. Relaxing the constraints on the masses, we have found an age t_alpha Cen=4850+-500 Myr, an initial helium mass fraction Y_i = 0.300+-0.008, and an initial metallicity (Z/X)_i=0.0459+-0.0019, with M_A=1.100+-0.006M_o and M_B=0.907+-0.006M_o for alpha Cen A&B.

  12. Asteroseismology and calibration of alpha Cen binary system

    E-Print Network [OSTI]

    F. Thevenin; J. Provost; P. Morel; G. Berthomieu; F. Bouchy; F. Carrier

    2002-06-17

    Using the oscillation frequencies of alpha Cen A recently discovered by Bouchy & Carrier, the available astrometric, photometric and spectroscopic data, we tried to improve the calibration of the visual binary system alpha Cen. With the revisited masses of Pourbaix et al. (2002) we do not succeed to obtain a solution satisfying all the seismic observational constraints. Relaxing the constraints on the masses, we have found an age t_alpha Cen=4850+-500 Myr, an initial helium mass fraction Y_i = 0.300+-0.008, and an initial metallicity (Z/X)_i=0.0459+-0.0019, with M_A=1.100+-0.006M_o and M_B=0.907+-0.006M_o for alpha Cen A&B.

  13. {alpha}-cluster states in N{ne}Z nuclei

    SciTech Connect (OSTI)

    Goldberg, V. Z.; Rogachev, G. V.

    2012-10-20

    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.

  14. Mapping the Cosmic Web with Ly-alpha Emission

    E-Print Network [OSTI]

    Steven Furlanetto; Joop Schaye; Volker Springel; Lars Hernquist

    2003-10-31

    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.

  15. 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

    2006-12-09

    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.

  16. Labeled ALPHA4BETA2 ligands and methods therefor

    DOE Patents [OSTI]

    Mukherjee, Jogeshwar; Pichika, Ramaiah; Potkin, Steven; Leslie, Frances; Chattopadhyay, Sankha

    2013-02-19

    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.

  17. Preparation and synthetic application of {alpha}-phenylthioethylsamarium compound

    SciTech Connect (OSTI)

    Kasuga, Y.; Matsubara, S.; Utimoto, K. [Kyoto Univ. (Japan)

    1995-12-31

    Although samarium(II) iodide-mediated reaction of organohalides with carbonyl compounds has been applied to various organic syntheses, intermediary organosamarium species could be detected only when HMPA exists in the reaction system. The authors now report the detection of {alpha}-phenylthioethylsamarium compound in the absence of HMPA and application to diastereoselective reaction with aldehydes. A treatment of the organosamarium reagent, prepared from 1-chloroethyl phenyl sulfide and samarium(II) iodide, with D{sub 2}O afforded 1-deuterioethyl phenyl sulfide in 53% yield (82% D). The reagent reacted with aldehyde containing a stereogenic center at {alpha}-position to give {beta}-hydroxysulfide with high diastereoselectivity. Reaction using Barbier type procedure afforded the same results. These results suggest that {alpha}-phenylthioethylsamarium species is also generated in the Barbier type reaction. Configurational stability of {alpha}-thiosubstituted alkylmetal compounds seems to depend on the applied metal. Hoffmann Test indicated that the configuration of {alpha}-phenylthloethylsamarium compound is unchanged during the reaction with aldehyde, while that of {alpha}-alkylthioalkyllithium is unstable.

  18. Neutrino Decay and Solar Neutrino Seasonal Effect

    E-Print Network [OSTI]

    Picoreti, R; de Holanda, P C; Peres, O L G

    2015-01-01

    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 $\

  19. Wood Decay in Silicified Gymnosperms from Antarctica

    E-Print Network [OSTI]

    Stubblefield, Sara P.; Taylor, Thomas N.

    1986-03-01

    of decay are evident: (1) A wall component, presumably lignin, is removed from the wall and middle lamella of infected tracheids, leaving a considerably thinner cellulose framework; and (2) the primary and secondary walls typically separate, and all wall...

  20. CP Violation in Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    T. Fukuyama; K. Matsuda; H. Nishiura

    1997-08-19

    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.

  1. Recent Results in Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Lisa J. Kaufman

    2013-05-14

    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.

  2. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    Gómez-Cadenas, J J

    2015-01-01

    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.

  3. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    J. J. Gómez-Cadenas; Justo Martín-Albo

    2015-02-25

    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.

  4. DIRECT PHOTONS FROM Y(3100) DECAY

    E-Print Network [OSTI]

    Ronan, M.T.

    2010-01-01

    to search for direct photons from 0(3100) decay. V* havedecay, but a sianal of high energy direct photons remains.this excess of direct photons wi*h OCD predictions and

  5. Double beta decay and neutrino mass models

    E-Print Network [OSTI]

    Helo, J C; Ota, T; Santos, F A Pereira dos

    2015-01-01

    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. Theory of top quark production and decay

    SciTech Connect (OSTI)

    Kuehn, J.H. [Universitaet Karlsruhe (Germany)

    1997-01-01

    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.

  7. Uncertainty evaluation of delayed neutron decay parameters 

    E-Print Network [OSTI]

    Wang, Jinkai

    2009-05-15

    In a nuclear reactor, delayed neutrons play a critical role in sustaining a controllable chain reaction. Delayed neutron’s relative yields and decay constants are very important for modeling reactivity control and have been studied for decades...

  8. LHC prospects for minimal decaying dark matter

    SciTech Connect (OSTI)

    Arcadi, Giorgio; Covi, Laura; Dradi, Federico, E-mail: giorgio.arcadi@theorie.physik.uni-goettingen.de, E-mail: laura.covi@theorie.physik.uni-goettingen.de, E-mail: federico.dradi@theorie.physik.uni-goettingen.de [Institute for Theoretical Physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany (Germany)

    2014-10-01

    We study the possible signals at LHC of the minimal models of decaying dark matter. Those models are characterized by the fact that DM interacts with SM particles through renormalizable coupling with an additional heavier charged state. Such interaction allows to produce a substantial abundance of DM in the early Universe via the decay of the charged heavy state, either in- or out-of-equilibrium. Moreover additional couplings of the charged particle open up decay channels for the DM, which can nevertheless be sufficiently long-lived to be a good DM candidate and within reach of future Indirect Detection observations. We compare the cosmologically favored parameter regions to the LHC discovery reach and discuss the possibility of simultaneous detection of DM decay in Indirect Detection.

  9. Leptonic Decays of Charged Pseudoscalar Mesons - 2015

    E-Print Network [OSTI]

    Jonathan L. Rosner; Sheldon Stone; Ruth S. Van de Water

    2015-09-07

    We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be used to test the unitarity of the first and second rows of the CKM matrix. Conversely, taking the CKM elements predicted by unitarity, one can infer "experimental" values for $f_P$ that can be compared with theory. These provide tests of lattice-QCD methods, provided new-physics contributions to leptonic decays are negligible at the current level of precision. This review is the basis of the article in the Particle Data Group's 2016 edition, updating the versions in Refs. [1-3].

  10. Neutrinoless double beta decay with scalar bilinears

    E-Print Network [OSTI]

    H. V. Klapdor-Kleingrothaus; U. Sarkar

    2002-11-18

    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.

  11. Rare meson decays into very light neutralinos

    SciTech Connect (OSTI)

    O'Leary, Ben [Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany)

    2010-02-10

    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.

  12. Searches for neutrinoless double beta decay

    E-Print Network [OSTI]

    B. Schwingenheuer

    2012-01-24

    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.

  13. Fidelity Decay for Phase Space Displacements

    E-Print Network [OSTI]

    Diego V. Bevilaqua; Eric J. Heller

    2004-09-03

    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

  14. First forbidden beta decay in light nuclei

    SciTech Connect (OSTI)

    Millener, D.J.; Warburton, E.K.

    1984-01-01

    Beta decay matrix elements for the operators sigma dot del and sigma dot r are calculated for eight J/sup +/ ..-->.. J/sup -/ or J/sup -/ ..-->.. J/sup +/ beta transitions. Results using harmonic oscillator wave functions differ markedly from those using more realistic Woods-Saxon wave functions. A substantial contribution to the sigma dot del matrix elements from pion exchange currents is required to reproduce the experimental beta decay rates. 15 references.

  15. More about excited bottomonium radiative decays

    E-Print Network [OSTI]

    Randy Lewis; R. M. Woloshyn

    2012-09-18

    Radiative decays of bottomonium are revisited, focusing on contributions from higher-order relativistic effects. The leading relativistic correction to the magnetic spin-flip operator at the photon vertex is found to be particularly important. The combination of O(v^6) effects in the nonrelativistic QCD action and in the transition operator moves previous lattice results for excited Upsilon decays into agreement with experiment.

  16. CP Violation in Other Bs Decays

    E-Print Network [OSTI]

    L. Zhang; for the LHCb Collaboration

    2012-08-24

    The recent experimental results of CP violation in Bs decays other than in the J/psi phi final state are discussed. Included are the resonant components and $\\phi_s$ determination in Bs -> J/psi pi+ pi-, CP asymmetries in Bs -> h+ h'- decays, and the Bs effective lifetimes in the CP-even state K+ K- and the CP-odd state J/psi f0(980).

  17. Rare top quark decays in extended models

    SciTech Connect (OSTI)

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2006-09-25

    Flavor changing neutral currents (FCNC) decays t {yields} H0 + c, t {yields} Z + c, and H0 {yields} t + c-bar are discussed in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions where FCNC decays may take place at tree-level and are only suppressed by the mixing between ordinary top and charm quarks, which is poorly constraint by current experimental values. The non-manifest case is also briefly discussed.

  18. Determination of alpha_S using hadronic event shape distributions of data taken with the OPAL detector

    E-Print Network [OSTI]

    Schieck, J

    2011-01-01

    The measurement of the strong coupling alpha_S using hadronic event shape distributions measured with the OPAL detector at center-of-mass energies between 91 and 209 GeV is summarized. For this measurement hadronic event shape distributions are compared to theoretical predictions based on next-to-next-to-leading-calculations (NNLO) and NNLO combined with resummed next-to-leading-logarithm calculations (NLLA). The combined result using NNLO calculations is alpha_S(MZ)=0.1201+-0.0008(stat.)+-0.0013(exp.)+-0.0010(had.)+-0.0024(theo.) and the result using NLLO and NLLA calculations is alpha_S(MZ)=0.1189+-0.0008(stat.)+-0.0016(exp.)=-0.0010(had.)+-0.0036(theo.), with both measurements being in agreement with the world average.

  19. 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)

    2011-12-16

    A collection of stories is presented on discoveries of 2{beta} decay (including neutrinoless one) which were refuted in the subsequent investigations.

  20. Recent Results on Semileptonic Decays at Babar

    SciTech Connect (OSTI)

    Serrano, Justine; /Orsay, LAL

    2011-11-07

    Some recent BABAR results on semileptonic decays are presented. They focus on the determination of the CKM matrix elements |V{sub ub}| and |V{sub cb}| in inclusive and exclusive b {yields} u{ell}v and b {yields} c{ell}v decays, and on form factors measurement in exclusive c {yields} s{ell}v decays. Semileptonic decays play a crucial role in the determination of the unitarity triangle parameters: decays of the b quark give access to the CKM matrix elements |V{sub ub}| and |V{sub cb}|, while charm decays provide a way to validate lattice QCD computations through form factors measurements. Such calculations provide theoretical inputs that are used, especially, in the b sector. A lot of new results have been obtained by the BABAR collaboration during the last years, thanks to the large b{bar b} and c{bar c} production cross-sections and to the large recorded statistics. Some of these measurements are presented here.

  1. Power Spectrum Analyses of Nuclear Decay Rates

    E-Print Network [OSTI]

    D. Javorsek II; P. A. Sturrock; R. N. Lasenby; A. N. Lasenby; J. B. Buncher; E. Fischbach; J. T. Gruenwald; A. W. Hoft; T. J. Horan; J. H. Jenkins; J. L. Kerford; R. H. Lee; A. Longman; J. J. Mattes; B. L. Morreale; D. B. Morris; R. N. Mudry; J. R. Newport; D. O'Keefe; M. A. Petrelli; M. A. Silver; C. A. Stewart; B. Terry

    2010-07-06

    We provide the results from a spectral analysis of nuclear decay data displaying annually varying periodic fluctuations. The analyzed data were obtained from three distinct data sets: 32Si and 36Cl decays reported by an experiment performed at the Brookhaven National Laboratory (BNL), 56Mn decay reported by the Children's Nutrition Research Center (CNRC), but also performed at BNL, and 226Ra decay reported by an experiment performed at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. All three data sets exhibit the same primary frequency mode consisting of an annual period. Additional spectral comparisons of the data to local ambient temperature, atmospheric pressure, relative humidity, Earth-Sun distance, and their reciprocals were performed. No common phases were found between the factors investigated and those exhibited by the nuclear decay data. This suggests that either a combination of factors was responsible, or that, if it was a single factor, its effects on the decay rate experiments are not a direct synchronous modulation. We conclude that the annual periodicity in these data sets is a real effect, but that further study involving additional carefully controlled experiments will be needed to establish its origin.

  2. Novel Weak Decays in Doubly Strange Systems

    E-Print Network [OSTI]

    A. Parreno; A. Ramos; C. Bennhold

    2001-06-22

    The strangeness-changing ($\\Delta S = 1$) weak baryon-baryon interaction is studied through the nonmesonic weak decay of double-$\\Lambda$ hypernuclei. Besides the usual nucleon-induced decay $\\Lambda N \\to N N$ we discuss novel hyperon-induced decay modes $\\Lambda \\Lambda \\to \\Lambda N$ and $\\Lambda \\Lambda \\to \\Sigma N$. These reactions provide unique access to the exotic $\\Lambda \\Lambda$K and $\\Lambda \\Sigma$K vertices which place new constraints on Chiral Pertubation Theory ($\\chi$PT) in the weak SU(3) sector. Within a meson-exchange framework, we use the pseudoscalar $\\pi,\\eta,K$ octet for the long-range part while parametrizing the short-range part through the vector mesons $\\rho, \\omega, K^*$. Realistic baryon-baryon forces for the $S=0,-1$ and -2 sectors account for the strong interaction in the initial and final states. For $^6_{\\Lambda \\Lambda}$He the new hyperon-induced decay modes account for up to 4% of the total nonmesonic decay rate. Predictions are made for all possible nonmesonic decay modes.

  3. 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

  4. Radiative-nonrecoil corrections of order {alpha}{sup 2}(Z{alpha}){sup 5} to the Lamb shift

    SciTech Connect (OSTI)

    Dowling, Matthew; Mondejar, Jorge; Piclum, Jan H.; Czarnecki, Andrzej [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada)

    2010-02-15

    We present results for the corrections of order {alpha}{sup 2}(Z{alpha}){sup 5} to the Lamb shift. We compute all the contributing Feynman diagrams in dimensional regularization and a general covariant gauge using a mixture of analytical and numerical methods. We confirm results obtained by other groups and improve their precision. Values of the 32''master integrals'' for this and similar problems are provided.

  5. Decay of the 9/2{sup -} isomer in {sup 181}Tl and mass determination of low-lying states in {sup 181}Tl, {sup 177}Au, and {sup 173}Ir

    SciTech Connect (OSTI)

    Andreyev, A. N.; Antalic, S.; Saro, S.; Ackermann, D.; Comas, V. F.; Heinz, S.; Heredia, J. A.; Hessberger, F. P.; Khuyagbaatar, J.; Kojouharov, I.; Kindler, B.; Lommel, B.; Mann, R.; Cocolios, T. E.; Elseviers, J.; Huyse, M.; Van Duppen, P. Van; Venhart, M.; Franchoo, S.; Hofmann, S.

    2009-08-15

    A detailed spectroscopic study of the neutron-deficient isotope {sup 181}Tl and the daughter of its {alpha} decay, {sup 177}Au, has been performed in the complete fusion reaction {sup 40}Ca+{sup 144}Sm{yields}{sup 184}Pb* at the velocity filter SHIP (GSI). The mass excess, excitation energy, and decay scheme of the isomeric 1.40(3) ms, 9/2{sup -} intruder state in {sup 181}Tl have been established for the first time. These results solve a long-standing puzzle of the unrealistically large reduced {alpha}-decay width of this isomer. Based on this, the previously unknown masses of the long-lived isomeric states in {sup 177}Au and {sup 173}Ir have been derived. In turn, it now allows the excitation energies of previously identified bands in {sup 177}Au and {sup 173}Ir to be deduced and compared with theoretical predictions. First measurements of {alpha}-decay branching ratios for {sup 181}Tl{sup m} and {sup 177}Au{sup m,g} are also reported.

  6. Numerical Code for LHCD Simulations with Self-consistent Treatment of Alpha Particles in Tokamak Geometry

    E-Print Network [OSTI]

    Numerical Code for LHCD Simulations with Self-consistent Treatment of Alpha Particles in Tokamak Geometry

  7. Modelling Neutral Particle Analyzer Measurements of High Energy Fusion Alpha-Particle Distributions in JET

    E-Print Network [OSTI]

    Modelling Neutral Particle Analyzer Measurements of High Energy Fusion Alpha-Particle Distributions in JET

  8. Estimate of B(B{yields}X{sub s}{gamma}) at O({alpha}{sub s}{sup 2})

    SciTech Connect (OSTI)

    Misiak, M.; Asatrian, H. M.; Hovhannisyan, A.; Poghosyan, V.; Bieri, K.; Ewerth, T.; Greub, C.; Czakon, M.; Czarnecki, A.; Slusarczyk, M.; Ferroglia, A.; Gambino, P.; Gorbahn, M.; Steinhauser, M.; Haisch, U.; Hurth, T.; Mitov, A.

    2007-01-12

    Combining our results for various O({alpha}{sub s}{sup 2}) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find B(B{yields}X{sub s}{gamma})=(3.15{+-}0.23)x10{sup -4} for E{sub {gamma}}>1.6 GeV in the B-meson rest frame. The four types of uncertainties: nonperturbative (5%), parametric (3%), higher-order (3%), and m{sub c}-interpolation ambiguity (3%) have been added in quadrature to obtain the total error.

  9. 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

    2005-08-11

    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.

  10. 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)

    2005-08-01

    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.

  11. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  12. Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  13. The search for neutrinoless double beta decay

    E-Print Network [OSTI]

    J. J. Gomez-Cadenas; J. Martin-Albo; M. Mezzetto; F. Monrabal; M. Sorel

    2012-01-16

    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.

  14. New experiment on the neutron radiative decay

    E-Print Network [OSTI]

    Khafizov R. U.; Kolesnikov I. A.; Tolokonnikov S. V.; Torokhov V. D.; Solovei V. A.; Kolhidashvili M. R.; Konorov I. A

    2009-10-05

    The report is dedicated to the preparation of the new experiment on the neutron radiative decay what is conducted for the last years. We started the experimental research of this neutron decay branch with the experiment conducted at ILL in 2002 and continued in another experiment at the second and third cycles at the FRMII reactor of the Technical University of Munich in 2005. In the first experiment we succeeded in measuring only the upper limit on the relative intensity (B.R.) of the radiative neutron decay and in the second we succeeded in discovering events of radiative neutron decay and measure its B.R.=(3.2+-1.6)10-3 (with C.L.=99.7% and gamma quanta energy over 35 keV). The obtained average B.R. value was approximately twice the theoretical value calculated earlier within the framework of the standard electroweak model. However, due to significant experimental error it would be preliminary to deduce that based on this finding a deviation from the standard model has been observed. To prove or disprove the existence of a deviation it is necessary to conduct a new experiment that would allow to measure the radiative peak in timing spectra with precision in the order of 1%. By the present time we have prepared a new experiment the main result of which would be the measurement of B.R. for the radiative branch of neutron decay with this precision.

  15. Experimental Investigation of Weak Non-Mesonic Decay of 10Be(Lambda)Hypernuclei at CEBAF

    SciTech Connect (OSTI)

    S. Majewski; L. Majling; A. Margaryan; L. Tang

    2005-08-05

    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.

  16. Measurements of CP-Violating Asymmetries in B0 to a1(1260)^{+-} pi^{-+} Decays

    E-Print Network [OSTI]

    F. Palombo

    2007-03-03

    We present measurements of CP-violating asymmetries in the decay B0 -> a_1(1260)^{+-} pi^{-+} with a_1(1260)^{+-} -> pi^{-+} pi^{+-} pi^{+-}. The data sample corresponds to 384 million B B-bar pairs collected with the BaBar detector at the PEP-II asymmetric B-factory at SLAC. We measure the CP-violating asymmetry A^{a1pi}_{CP}=-0.07+-0.07+-0.02, the mixing-induced CP violation parameter S_{a1pi}= 0.37 +-0.21+-0.07, the direct CP violation parameter C_{a1pi}=-0.10+-0.15+-0.09, and the parameters DeltaC_{a1pi}=0.26+-0.15+-0.07 and DeltaS_{a1pi}=-0.14+-0.21+-0.06. From these measured quantities we exstract the angle alpha_{eff}= 78.6^{0} +- 7.3^{0}.

  17. Complexation of americium with {alpha}-d-iso-saccharinate

    SciTech Connect (OSTI)

    Allard, S.; Knutsson, A.; Oedegaard-Jensen, A.; Ekberg, C.; Jolsteraa, R.

    2008-07-01

    Under alkaline conditions, cellulose will degrade, with iso-saccharinate being the dominant end-product. One of the formed diastereomers, the {alpha}-D-iso-saccharinate, is a strong complexing agent for tri- and tetravalent actinides and is the dominant conformation at pH > 5, rendering other conformations insignificant at neutral to alkaline conditions. The presence of {alpha}-D-iso-saccharinate increases the amount of metal in solution and also affects the surface interactions. Understanding this complexation is of relevance for long-term repository assessments. This study has investigated the complexation of americium with {alpha}-D-iso-saccharinate using solvent-extraction and radioanalytical techniques at 25 deg. C. The stability constants for the complexation reactions were determined by curve fitting of a distribution-ratio equation to experimental data.

  18. Uncertainties on $\\alpha_S$ in the MMHT2014 global PDF analysis and implications for SM predictions

    E-Print Network [OSTI]

    Harland-Lang, L A; Motylinski, P; Thorne, R S

    2015-01-01

    We investigate the uncertainty in the value of the strong coupling $\\alpha_S(M_Z^2)$ when allowing it to be a free parameter in the recent MMHT global analyses of deep-inelastic and related hard scattering data that was undertaken to determine the parton distribution functions (PDFs) of the proton. The analysis uses the standard framework of leading twist fixed--order collinear factorisation in the ${\\overline {\\rm MS}}$ scheme. We study the constraints on the value of $\\alpha_S(M_Z^2)$ coming from the individual data sets by repeating the NNLO and NLO global analyses at various fixed values of $\\alpha_S(M_Z^2)$ about its optimum values, spanning the range $\\alpha_S(M_Z^2)=0.108$ to $0.128$ in units of $0.001$, and making all PDFs sets available. The inclusion of the measurements of the cross section for inclusive $t\\bar{t}$ production in the global fit allows us to explore the correlation between the values taken for the mass $m_t$ of the top quark and $\\alpha_S(M_Z^2)$. We find that the best fit values are ...

  19. Inflaton dark matter from incomplete decay

    E-Print Network [OSTI]

    Mar Bastero-Gil; Rafael Cerezo; Joao G. Rosa

    2015-01-22

    We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the mass of the inflaton decay products is field-dependent, one can construct models, endowed with an appropriate discrete symmetry, where inflaton decay is kinematically forbidden at late times and only occurs during the initial stages of field oscillations after inflation. We show that this is sufficient to ensure the transition to a radiation-dominated era and that inflaton particles typically thermalize in the process. They eventually decouple and freeze out, yielding a thermal dark matter relic. We discuss possible implementations of this generic mechanism within consistent cosmological and particle physics scenarios, for both single-field and hybrid inflation.

  20. Lepton Flavor Violating Decays - Review & Outlook

    E-Print Network [OSTI]

    Toshinori Mori

    2006-05-31

    Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.

  1. 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)

    2009-11-09

    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.

  2. Phenomenology of neutrinoless double beta decay

    E-Print Network [OSTI]

    M. Hirsch

    2006-09-15

    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.

  3. Uranium and thorium decay series disequilibria in young volcanic rocks

    SciTech Connect (OSTI)

    Williams, R.W.

    1988-01-01

    Two of the central questions in igneous geochemistry that study of radioactive disequilibria can help to answer are: what are the rates of magma genesis; and what are the timescales of magma separation and transport. In addition to the temporal information that may be extracted from disequilibria data, the {sup 230}Th/{sup 232}Th of a young rock may be used as a tracer of the Th/U ratio of its source region. Measurements were made by isotope dilution alpha-spectrometry of {sup 238}U, {sup 234}U, {sup 230}Th, and {sup 232}Th in 20 subduction related, 3 oceanic intraplate, and 10 continental intraplate volcanics. {sup 210}Pb was measured in all, {sup 226}Ra was measured in about half, and {sup 228}Th was measured in 10 of the most recent samples. Disequilibrium between {sup 228}Th and {sup 232}Th was found only in the Nacarbonatite samples from Oldoinyo Lengai volcano in Tanzania, which is attributable to {sup 228}Ra/{sup 232}Th {approximately} 27 at the time of eruption. These rocks also have {sup 226}Ra/{sup 230}Th > 60. Three Ra-enrichment models are developed which constrain carbonatite magma formation at less than 20 years before eruption. The effects of different partial melting processes on the {sup 238}U decay series are investigated. If mid-ocean ridge basalts are formed by a dynamic melting process, the {sup 230}Th/{sup 232}Th of the basalts provides a minimum estimate of the Th/U ratio of the source region. The {sup 238}U enrichment in arc volcanics is probably the results of metasomatism of the source by fluids derived from the subducting slab, and the {sup 230}Th enrichment observed for other volcanics is probably due to the partial melting process in the absence of U-bearing fluids.

  4. Exotic Decays Of A Heavy Neutral Higgs Through HZ/AZ Channel

    E-Print Network [OSTI]

    Baradhwaj Coleppa; Felix Kling; Shufang Su

    2014-09-25

    Models of electroweak symmetry breaking with extended Higgs sectors are theoretically well motivated. In this study, we focus on the Two Higgs Doublet Model with a low energy spectrum containing scalars $H$ and a pseudoscalar $A$. We study the decays $A\\rightarrow HZ$ or $H\\rightarrow AZ$, which could reach sizable branching fractions in certain parameter regions. With detailed collider analysis, we obtain model independent exclusion bounds as well as discovery reach at the 14 TeV LHC for the process: $gg\\rightarrow A/H\\rightarrow HZ/AZ$, looking at final states bbll, \\tau\\tau ll and ZZZ(4l2j) for l =e,\\mu. We further interpret these bounds in the context of the Type II Two Higgs Doublet Model, considering three different classes of processes: $A\\rightarrow h^0Z$, $A\\rightarrow H^0Z$, and $H^0 \\rightarrow AZ$, in which $h^0$ and $H^0$ are the light and heavy CP-even Higgses respectively. For 100 fb$^{-1}$ integrated luminosity at the 14 TeV LHC, we find that for parent particle mass around 300-400 GeV, $A\\rightarrow h^0Z$ has the greatest reach when $H^0$ is interpreted as the 126 GeV Higgs: most regions in the tan\\beta-sin(\\beta-\\alpha) parameter space can be covered by exclusion and discovery. For 126 GeV $h^0$, only relatively small tan\\betadiscovery). For $A\\rightarrow H^0Z$, the reach is typically restricted to sin$(\\beta-\\alpha)\\sim\\pm 1$ with tan\\beta discovery reach possibly extending to all values of tan\\beta. A study of exotic decays of extra Higgses would extend the reach at the LHC and provides nice complementarity to conventional Higgs search channels.

  5. Lyman alpha Transfer in a thick, dusty, and static medium

    E-Print Network [OSTI]

    Sang-Hyeon Ahn; Hee-Won Lee; Hyung-Mok Lee

    2000-06-13

    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.

  6. Direct analysis of air filter samples for alpha emitting isotopes

    SciTech Connect (OSTI)

    Mohagheghi, A.H.; Ghanbari, F.; Ebara, S.B.; Enghauser, M.E. [Sandia National Labs., Albuquerque, NM (United States); Bakhtiar, S.N. [Westinghouse WIPP, Carlsbad, NM (United States)

    1997-04-01

    The traditional method for determination of alpha emitting isotopes on air filters has been to process the samples by radiochemical methods. However, this method is too slow for cases of incidents involving radioactive materials where the determination of personnel received dose is urgent. A method is developed to directly analyze the air filters taken from personal and area air monitors. The site knowledge is used in combination with alpha spectral information to identify isotopes. A mathematical function is developed to estimate the activity for each isotope. The strengths and weaknesses of the method are discussed.

  7. First-principles elastic properties of (alpha)-Pu

    SciTech Connect (OSTI)

    Soderlind, P; Klepeis, J E

    2008-11-04

    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.

  8. Electromagnetic corrections to pseudoscalar decay constants

    E-Print Network [OSTI]

    Benjamin Glaessle; Gunnar S. Bali

    2011-11-16

    The effects of electromagnetic interactions on pseudoscalar decay constants are investigated. Using a compact QED and QCD action we are able to resolve differences of about 0.1 MeV. We obtain the preliminary results f_pi^0-f_pi^+/- =0.09(3) MeV and f_D^0-f_D^+/- =0.79(11) MeV for light and charmed pseudoscalar decay constants on a N_f=2 nonperturbatively improved Sheikholeslami-Wohlert ensemble.

  9. Study of the K0L ???????¯decay

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

    Ogata, R.; Suzuki, S.; Ahn, J. K.; Akune, Y.; Baranov, V.; Chen, K. F.; Comfort, J.; Doroshenko, M.; Fujioka, Y.; Hsiung, Y. B.; et al

    2011-09-21

    The rare decay K0L???????? was studied with the E391a detector at the KEK 12-GeV proton synchrotron. Based on 9.4×10? K0L decays, an upper limit of 8.1×10?? was obtained for the branching fraction at 90% confidence level. We also set a limit on the K0L?????X (X?invisible particles) process; the limit on the branching fraction varied from 7.0×10?? to 4.0×10?? for the mass of X ranging from 50 MeV/c² to 200 MeV/c².

  10. Neutrinoless double beta decay and neutrino masses

    SciTech Connect (OSTI)

    Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2012-07-27

    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.

  11. The double-beta decay: Theoretical challenges

    SciTech Connect (OSTI)

    Horoi, Mihai

    2012-11-20

    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.

  12. On the neutrinoless double ?{sup +}/EC decays

    SciTech Connect (OSTI)

    Suhonen, Jouni

    2013-12-30

    The neutrinoless double positron-emission/electron-capture (0??{sup +}/EC) decays are studied for the magnitudes of the involved nuclear matrix elements (NMEs). Decays to the ground state, 0{sub gs}{sup +}, and excited 0{sup +} states are discussed. The participant many-body wave functions are evaluated in the framework of the quasiparticle random-phase approximation (QRPA). Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. The channels ?{sup +}?{sup +}, ?{sup +}EC, and the resonant neutrinoless double electron capture (R0?ECEC) are discussed.

  13. 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

    2012-09-13

    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.

  14. 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)

    2011-11-23

    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.

  15. Symmetry violations in nuclear and neutron $\\beta$ decay

    E-Print Network [OSTI]

    Vos, K K; Timmermans, R G E

    2015-01-01

    The role of $\\beta$ decay as a low-energy probe of physics beyond the Standard Model is reviewed. Traditional searches for deviations from the Standard Model structure of the weak interaction in $\\beta$ decay are discussed in the light of constraints from the LHC and the neutrino mass. Limits on the violation of time-reversal symmetry in $\\beta$ decay are compared to the strong constraints from electric dipole moments. Novel searches for Lorentz symmetry breaking in the weak interaction in $\\beta$ decay are also included, where we discuss the unique sensitivity of $\\beta$ decay to test Lorentz invariance. We end with a roadmap for future $\\beta$-decay experiments.

  16. THE TWO REGIMES OF PHOTOSPHERIC MOTIONS IN {alpha} HYDRA

    SciTech Connect (OSTI)

    Gray, David F., E-mail: dfgray@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2013-02-10

    High-resolution spectroscopic observations of {alpha} Hya were acquired between 2003 and 2010. Analysis of line shifts, differential shifts, line widths, and line bisectors points to two regimes of velocity fields in the photosphere of {alpha} Hya: (1) normal granulation embedded in (2) large convection cells. Variations occur on a wide range of timescales, from several years on down. Radial velocity variations, which are irregular and span 786 m s{sup -1}, have a distribution consistent with a true mean rise velocity of the large cells of {approx}725 m s{sup -1} and a dispersion of {approx}220 m s{sup -1}. The distribution of granulation velocities, as measured from the widths of spectral lines, shows only small variations, consistent with the two regime concepts. On the multi-year timescale, radial velocity changes, small temperature variations ({approx}10 K), and small line-width variations ({approx}<0.8%) track each other, possibly with phase shifts. The granulation velocity gradient for {alpha} Hya is about half as large as the Sun's and no variation with time was seen, implying that any variation in velocity gradient from one large cell to the next must be less than a few percent. The asymmetry in the granulation velocity distribution, as specified in the flux deficit, is smaller than expected for {alpha} Hya's position in the HR diagram and appears to be variable.

  17. CRAD, Management- Oak Ridge National Laboratory TRU ALPHA LLWT Project

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a November 2003 assessment of the Management Program portion of an Operational Readiness Review of the Oak Ridge National Laboratory TRU ALPHA LLWT Project.

  18. CRAD, Training- Oak Ridge National Laboratory TRU ALPHA LLWT Project

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a November 2003 assessment of the Training Program portion of an Operational Readiness Review of the Oak Ridge National Laboratory TRU ALPHA LLWT Project.

  19. H\\alpha\\ Emission Variability in Active M Dwarfs

    E-Print Network [OSTI]

    Bell, Keaton J; Davenport, James R A; Hawley, Suzanne L; West, Andrew A; Rogel, Allen B

    2011-01-01

    We use ~12,000 spectra of ~3,500 magnetically active M0-M9 dwarfs from the Sloan Digital Sky Survey taken at 10-15 minute intervals, together with ~300 spectra of ~60 M0-M8 stars obtained hourly with the Hydra multi-object spectrometer, to probe H\\alpha\\ variability on timescales of minutes to weeks. With multiple observations for every star examined, we are able to characterize fluctuations in H\\alpha emission as a function of activity strength and spectral type. Stars with greater magnetic activity (as quantified by L_H\\alpha/L_bol) are found to be less variable at all spectral types. We attribute this result to the stronger level of persistent emission in the high activity stars, requiring a larger heating event in order to produce measurable variability. We also construct H\\alpha\\ structure functions to constrain the timescale of variability. The more active objects with lower variability exhibit a characteristic timescale longer than an hour, likely due to larger, longer lasting heating events, while the...

  20. Elementary processes underlying alpha channeling in tokamaks N. J. Fisch

    E-Print Network [OSTI]

    to 198.125.232.144. Redistribution subject to AIP license or copyright; see http of the energy in these alpha particles to waves that then transfer or channel this energy to fuel ions rather make a significant difference in the economical feasibility of controlled fusion energy. It is only

  1. Preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters

    DOE Patents [OSTI]

    Gogate, Makarand Ratnakar (Durham, NC); Spivey, James Jerry (Cary, NC); Zoeller, Joseph Robert (Kingsport, TN)

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  2. Preparation of {alpha}, {beta}-unsaturated carboxylic acids and anhydrides

    DOE Patents [OSTI]

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Tustin, G.C.

    1998-01-20

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  3. Preparation of .alpha., .beta.-unsaturated carboxylic acids and anhydrides

    DOE Patents [OSTI]

    Spivey, James Jerry (Cary, NC); Gogate, Makarand Ratnakav (Durham, NC); Zoeller, Joseph Robert (Kingsport, TN); Tustin, Gerald Charles (Kingsport, TN)

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  4. Preparation of {alpha},{beta}-unsaturated carboxylic acids and esters

    DOE Patents [OSTI]

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.

    1998-09-15

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and esters thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic acid, ester or anhydride in the presence of a catalyst comprising an oxide of niobium.

  5. On the Lyman-alpha Emission of Starburst Galaxies

    E-Print Network [OSTI]

    David Valls-Gabaud

    1993-06-13

    Nearby starburst galaxies have consistently shown anomalous Ly-alpha/H-beta ratios. By re-analysing the published IUE/optical observations, we show that most starbursts present a normal Ly-alpha emission, consistent with case B recombination theory, provided extinction laws appropriate to their metallicities are used. This implies that extinction is more important than multiple resonant scattering effects. The anomalous emission and absorption lines present in a few remaining galaxies are simply explained if they are observed in the post-burst phase, between about 10$^7$ and 10$^8$ yrs after the start of the burst. We use updated stellar population synthesis models to show that anomalous ratios are produced by the aging of stellar populations, since the underlying stellar Ly-alpha line is important in the cooler massive stars. The inferred low-duty cycle of massive star formation accounts naturally for the failure to detect large numbers of Ly-alpha--emitting galaxies in deep surveys and at high redshift. Some testable predictions of the proposed scenario are also discussed.

  6. Vacuum decay into Anti de Sitter space

    E-Print Network [OSTI]

    Juan Maldacena

    2011-01-10

    We propose an interpretation of decays of a false vacuum into an $AdS$ region. The $AdS$ region is interpreted in terms of a dual field theory living on an end of the world brane which expands into the false vacuum.

  7. The COBRA Double Beta Decay Experiment

    SciTech Connect (OSTI)

    Dawson, J. V. [Department of Physics and Astronomy, University of Sussex, Brighton. BN1 9QH (United Kingdom)

    2007-03-28

    The progress of the COBRA neutrinoless double beta decay experiment is discussed. Potential backgrounds are described. Estimates on the contamination levels of 214Bi in the detectors have been made using previously acquired low background data. New crystals with a different passivation material show an improved background count rate of approximately one order of magnitude.

  8. Pathways to Rare Baryonic B Decays

    E-Print Network [OSTI]

    Wei-Shu Hou; A. Soni

    2000-08-09

    We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\\eta^\\prime$ is very likely as large as or even a bit larger than two body $K\\pi/\\pi\\pi$ modes. We extend our argument, in weaker form, to $B\\to \\gamma + X_s$ and $\\ell\

  9. Study of Michel spectrum of tau decay

    E-Print Network [OSTI]

    Ackerman, Nicole (Nicole L.)

    2007-01-01

    This thesis is the beginning of a larger project to use BaBar to examine weak couplings through leptonic [tau] decay. I will use the ratio of Br... and Br... and the Michel parameters [rho] and [eta]. which describe the ...

  10. Kaon Decays from AdS/QCD

    E-Print Network [OSTI]

    Martin Schvellinger

    2008-06-03

    We briefly review one of the current applications of the AdS/CFT correspondence known as AdS/QCD and discuss about the calculation of four-point quark-flavour current correlation functions and their applications to the calculation of observables related to neutral kaon decays and neutral kaon mixing processes.

  11. Search for rare and forbidden eta ' decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, X.

    2000-01-01

    We have searched for rare and forbidden decays of the eta' meson in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb(-1) of e(+)e(-) collisions at 10.6 GeV center-of-mass energy at the Cornell Electron Storage Ring. We...

  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.

    1998-05-01

    Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79fb(-1) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis...

  13. Rare meson decays into very light neutralinos

    SciTech Connect (OSTI)

    Dreiner, H. K.; Grab, S.; Koschade, Daniel; Kraemer, M.; O'Leary, Ben; Langenfeld, Ulrich [Bethe Center for Theoretical Physics and Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen, Germany and Centre for Research in String Theory, Department of Physics, Queen Mary, University of London, E1 4NS London (United Kingdom); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany); DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

    2009-08-01

    We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the minimal supersymmetric standard model (MSSM) with and without minimal flavor violation. We present explicit formulas for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e., a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for nonminimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC.

  14. Neutrinoless double beta decay in seesaw models

    E-Print Network [OSTI]

    Mattias Blennow; Enrique Fernandez-Martinez; Jacobo Lopez-Pavon; Javier Menendez

    2014-05-12

    We study the general phenomenology of neutrinoless double beta decay in seesaw models. In particular, we focus on the dependence of the neutrinoless double beta decay rate on the mass of the extra states introduced to account for the Majorana masses of light neutrinos. For this purpose, we compute the nuclear matrix elements as functions of the mass of the mediating fermions and estimate the associated uncertainties. We then discuss what can be inferred on the seesaw model parameters in the different mass regimes and clarify how the contribution of the light neutrinos should always be taken into account when deriving bounds on the extra parameters. Conversely, the extra states can also have a significant impact, cancelling the Standard Model neutrino contribution for masses lighter than the nuclear scale and leading to vanishing neutrinoless double beta decay amplitudes even if neutrinos are Majorana particles. We also discuss how seesaw models could reconcile large rates of neutrinoless double beta decay with more stringent cosmological bounds on neutrino masses.

  15. Nuclear physics aspects of double beta decay

    E-Print Network [OSTI]

    Petr Vogel

    2008-07-15

    Comprehensive description of the phenomenology of the $\\beta\\beta$ decay is given, with emphasis on the nuclear physics aspects. After a brief review of the neutrino oscillation results and of motivation to test the lepton number conservation, the mechanism of the $0\

  16. Adaptive cache decay Paolo Bennati, Roberto Giorgi

    E-Print Network [OSTI]

    Giorgi, Roberto

    to save power. Our idea is to adaptively select mostly used cache lines. We found that this can MiBench suite for ARM based processor, show 13% improvement in leakage saving and 21% in EDP versus drowsy cache and 52% improvement in leakage saving and 65% in EDP versus cache decay (in average

  17. Scalar Mesons in B-decays

    SciTech Connect (OSTI)

    Minkowski, Peter; Ochs, Wolfgang

    2006-02-11

    We summarize some persistent problems in scalar spectroscopy and discuss what could be learned here from charmless B-decays. Recent experimental results are discussed in comparison with theoretical expectations: a simple model based on penguin dominance leads to various symmetry relations in good agreement with recent data; a factorisation approach yields absolute predictions of rates.

  18. Rare semi-leptonic B meson decays 

    E-Print Network [OSTI]

    Lyon, James David

    2014-06-28

    In this thesis, novel corrections to B ? X? and B ? Xl+l- decays, where X is a pseudoscalar or vector meson, are presented. These are the chromomagnetic matrix element, weak annihilation in a general four-quark operator basis and a long...

  19. Neutrinoless Double Beta Decay in Light of SNO Salt Data

    E-Print Network [OSTI]

    Murayama, Hitoshi

    2009-01-01

    Beta Decay in Light of SNO Salt Data Hitoshi Murayama andBeta Decay in Light of SNO Salt Data Hitoshi Murayama ? andIn the SNO data from its salt run, probably the most signi?

  20. Method of predicting mechanical properties of decayed wood

    DOE Patents [OSTI]

    Kelley, Stephen S.

    2003-07-15

    A method for determining the mechanical properties of decayed wood that has been exposed to wood decay microorganisms, comprising: a) illuminating a surface of decayed wood that has been exposed to wood decay microorganisms with wavelengths from visible and near infrared (VIS-NIR) spectra; b) analyzing the surface of the decayed wood using a spectrometric method, the method generating a first spectral data of wavelengths in VIS-NIR spectra region; and c) using a multivariate analysis to predict mechanical properties of decayed wood by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of wavelengths in VIS-NIR spectra obtained from a reference decay wood, the second spectral data being correlated with a known mechanical property analytical result obtained from the reference decayed wood.

  1. Weighted Energy Decay for 1D Dirac Equation

    E-Print Network [OSTI]

    E. Kopylova

    2011-02-10

    We obtain a dispersive long-time decay in weighted energy norms for solutions of the 1D Dirac equation with generic potential. The decay extends the results obtained by Jensen, Kato and Murata for the Schr\\"odinger equations.

  2. Stretched exponential decay of Majorana edge modes in many-body localized Kitaev chains under dissipation

    E-Print Network [OSTI]

    Alexander Carmele; Markus Heyl; Christina Kraus; Marcello Dalmonte

    2015-07-22

    We investigate the resilience of symmetry-protected topological edge states at the boundaries of Kitaev chains in the presence of a bath which explicitly introduces symmetry-breaking terms. Specifically, we focus on single-particle losses and gains, violating the protecting parity symmetry, which could generically occur in realistic scenarios. In homogeneous systems, we show that the Majorana mode decays exponentially fast. However, we find that it is possible to substantially increase its life-time by eliminating the dissipative dynamics close to the edges. Most importantly, we demonstrate that the Majorana mode can be further stabilized by the inclusion of disorder where the decay of the Majorana converts into a stretched exponential form implying an exponential gain in stability compared to the homogeneous case. In particular, for pure loss dynamics we find a universal exponent $\\alpha \\simeq 2/3$. We show that this holds both in the Anderson and many-body localized regimes. Our results thus provide a concrete recipe to stabilize edge states even in the presence of symmetry-breaking environments.

  3. Hybrid meson decay from lattice QCD

    E-Print Network [OSTI]

    Ziwen Fu

    2012-09-10

    Besides the conventional hadrons containing valence quarks and valence antiquarks, quantum chromodynamics (QCD) suggests the existence of the hybrid hadrons containing valence gluons in addition to the quarks and antiquarks, and some experiments may have found some. A decisive experimental confirmation of its existence, however, is still needed. At present, lattice simulations have offered the practicable ways of theoretically guiding us to search for the hybrid states. In this dissertation, we study the spectroscopy and the decay rate of the heavy hybrid mesons made of a heavy $b$ quark, a heavy $\\bar b$ antiquark, and a gluon ($b\\bar{b}g$) to selected channels, and use lattice methods to extract the transition matrix elements in full QCD. We are particular interested in the spin-exotic hybrid mesons. For sufficiently heavy quarks (e.g., $b$ quark), we use the leading Born-Oppenheimer (LBO) approximation to calculate the static potential energy at all $b\\bar{b}$ separations. Then, by solving the Schr\\"odinger equation with this potential, we reconstruct the motion of the heavy quarks. In a similar way we can determine decay rates. In this dissertation, we use the numerical lattice method to calculate the mass of the $f_0$ meson at a single lattice spacing and light quark mass, namely, $m_{f_0} = (768 \\pm 136)$ MeV. Most of all we consider the decay channels involving the production of a scalar meson. We obtain the partial decay rate ($\\Gamma$) for the channel $ H \\rightarrow \\chi_b + \\pi + \\pi $, namely, $ \\Gamma = 3.62(98)$ MeV. All of our results are consistent with those of other researchers. Knowledge of the masses and the decay rates should help us considerably in experimental searches for the hybrid mesons.

  4. 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 experimental bound [11] on neutrinoless double beta decay (## 0# ). The only way out would be to have two

  5. Search for neutrinoless decays of the tau lepton

    E-Print Network [OSTI]

    Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Lam, H.

    1994-10-01

    . The upper limits obtained for 22 decay branching fractions are several times more stringent than those set previously....

  6. Search for neutrinoless double beta decay with NEMO 3 experiment

    E-Print Network [OSTI]

    Zornitza Daraktchieva

    2009-01-18

    NEMO 3 experiment is designed to search for neutrinoless double beta decay. It is located in the Modane Underground Laboratory (LSM) and has been taking data since February 2003. The half- lives of two neutrino beta decay have been measured for seven isotopes. No evidence of neutrinoless double beta decay has been found. The limits on both the half-lives of the neutrinoless double beta decay and the corresponding Majorana effective masses are derived

  7. Neutrinoless Double Beta Decay and Physics Beyond the Standard Model

    E-Print Network [OSTI]

    Frank F. Deppisch; Martin Hirsch; Heinrich Päs

    2012-08-03

    Neutrinoless double beta decay is the most powerful tool to probe not only for Majorana neutrino masses but for lepton number violating physics in general. We discuss relations between lepton number violation, double beta decay and neutrino mass, review a general Lorentz invariant parametrization of the double beta decay rate, highlight a number of different new physics models showing how different mechanisms can trigger double beta decay, and finally discuss possibilities to discriminate and test these models and mechanisms in complementary experiments.

  8. Sensitivity of CUORE to Neutrinoless Double-Beta Decay

    E-Print Network [OSTI]

    Alessandria, F.

    2013-01-01

    of CUORE to Neutrinoless Double-Beta Decay b c,:L d e f F .s t results on neutrinoless double beta decay of T e w i t hthe study of neutrinoless double beta decay, J . C r y s t .

  9. The Majorana Neutrinoless Double-Beta Decay Experiment

    E-Print Network [OSTI]

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

    The Majorana Neutrinoless Double-Beta Decay Experiment Pre-conceptual Design Proposal November 22 Motivation for Neutrinoless Double-Beta Decay Experiments . . . . . . . . . 4 2.1.1 Community Guidance Neutrinoless Double-Beta Decay Results . . . . . . . . . . . . . . . . . . . . 12 2.5 Next

  10. Network Stability under Alpha Fair Bandwidth Allocation with General File Size Distribution

    E-Print Network [OSTI]

    fair bandwidth allocation, with any positive alpha parameter, a Lyapunov function is constructed1 Network Stability under Alpha Fair Bandwidth Allocation with General File Size Distribution. Cornell University, Ithaca, NY. Swinburne University of Technology, Australia. Abstract--Rate allocation

  11. Comparison of T cell receptor alpha, beta, and gamma gene rearrangement and expression in T cell acute lymphoblastic leukemia.

    E-Print Network [OSTI]

    Hara, Junichi; Benedict, Stephen H.; Champagne, Eric; Mak, Tak W.; Minden, Mark; Gelfand, Erwin W.

    1988-04-01

    We have analyzed the configuration of the T cell receptor (TCR) alpha gene using newly developed genomic joining region (J alpha) probes, which cover approximately 80 kb of the J alpha region upstream from the constant ...

  12. TauDecay: a library to simulate polarized tau decays via FeynRules and MadGraph5

    E-Print Network [OSTI]

    Kaoru Hagiwara; Tong Li; Kentarou Mawatari; Junya Nakamura

    2014-12-15

    TauDecay is a library of helicity amplitudes to simulate polarized tau decays, constructed in the FeynRules and MadGraph5 framework. Together with the leptonic mode, the decay library includes the main hadronic modes, \\tau \\to \

  13. Alpha channeling in rotating plasma with stationary waves Abraham J. Fetterman and Nathaniel J. Fisch

    E-Print Network [OSTI]

    particle energy. Alpha channeling uses radiofrequency waves to remove alpha particles collisionlessly at low energy. It is shown that stationary magnetic fields with high n can be used for this purpose, and simulations indicate that a large fraction of the alpha energy can be converted to rotation energy. © 2010

  14. INSTABILITIES DRIVEN BY THE DRIFT AND TEMPERATURE ANISOTROPY OF ALPHA PARTICLES IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Verscharen, Daniel; Bourouaine, Sofiane; Chandran, Benjamin D. G. E-mail: s.bourouaine@unh.edu

    2013-08-20

    We investigate the conditions under which parallel-propagating Alfven/ion-cyclotron (A/IC) waves and fast-magnetosonic/whistler (FM/W) waves are driven unstable by the differential flow and temperature anisotropy of alpha particles in the solar wind. We focus on the limit in which w{sub Parallel-To {alpha}} {approx}> 0.25v{sub A}, where w{sub Parallel-To {alpha}} is the parallel alpha-particle thermal speed and v{sub A} is the Alfven speed. We derive analytic expressions for the instability thresholds of these waves, which show, e.g., how the minimum unstable alpha-particle beam speed depends upon w{sub Parallel-To {alpha}}/v{sub A}, the degree of alpha-particle temperature anisotropy, and the alpha-to-proton temperature ratio. We validate our analytical results using numerical solutions to the full hot-plasma dispersion relation. Consistent with previous work, we find that temperature anisotropy allows A/IC waves and FM/W waves to become unstable at significantly lower values of the alpha-particle beam speed U{sub {alpha}} than in the isotropic-temperature case. Likewise, differential flow lowers the minimum temperature anisotropy needed to excite A/IC or FM/W waves relative to the case in which U{sub {alpha}} = 0. We discuss the relevance of our results to alpha particles in the solar wind near 1 AU.

  15. The 28th International Cosmic Ray Conference 1 The Alpha Magnetic Spectrometer on the International

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    The 28th International Cosmic Ray Conference 1 The Alpha Magnetic Spectrometer on the International", I.N.F.N Sez. Roma1, Roma, Italy Abstract The Alpha Magnetic Spectrometer (AMS) is a particle physics Academy Press, Inc. #12;2 Fig. 1. The Alpha Magnetic Spectrometer on the International Space Station. e

  16. 2786 IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 52, NO. 6, DECEMBER 2005 The Alpha Magnetic Spectrometer

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    , superconducting spectrom- eter. I. INTRODUCTION THE Alpha Magnetic Spectrometer (AMS) is a high-energy particle2786 IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 52, NO. 6, DECEMBER 2005 The Alpha Magnetic Spectrometer on the International Space Station B. Borgia on behalf of AMS Collaboration Abstract--The Alpha

  17. D meson hadronic decays at CLEO-c

    SciTech Connect (OSTI)

    Yang, Fan; /Fermilab

    2011-01-01

    The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.

  18. The nuclear matrix elements for neutrinoless double beta decay

    SciTech Connect (OSTI)

    Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina, SK-84248 Bratislava (Slovakia)

    2007-10-12

    The status of calculation of the neutrinoless double beta decay (0{nu}{beta}{beta}-decay) nuclear matrix elements (NME's) is reviewed. The spread of published values of NME's is discussed. The main attention is paid to the recent progress achieved in the evaluation of the 0{nu}{beta}{beta}-decay NME's in the framework of the quasiparticle random phase approximation (QRPA). The obtained results are compared with those of the nuclear shell model. The problem of reliable determination of the 0{nu}{beta}{beta}-decay NME's is addressed. The uncertainty in NME's are analyzed and further progress in calculation of the 0{nu}{beta}{beta}-decay NME's is outlined.

  19. Extra dimensions, orthopositronium decay, and stellar cooling

    E-Print Network [OSTI]

    Alexander Friedland; Maurizio Giannotti

    2007-09-14

    In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.

  20. Cold Positrons from Decaying Dark Matter

    SciTech Connect (OSTI)

    Boubekeur, Lotfi; Dodelson, Scott; Vives, Oscar

    2012-11-01

    Many models of dark matter contain more than one new particle beyond those in the Standard Model. Often heavier particles decay into the lightest dark matter particle as the Universe evolves. Here we explore the possibilities that arise if one of the products in a (Heavy Particle) $\\rightarrow$ (Dark Matter) decay is a positron, and the lifetime is shorter than the age of the Universe. The positrons cool down by scattering off the cosmic microwave background and eventually annihilate when they fall into Galactic potential wells. The resulting 511 keV flux not only places constraints on this class of models but might even be consistent with that observed by the INTEGRAL satellite.

  1. JUNO and Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Shao-Feng Ge; Werner Rodejohann

    2015-07-20

    We study the impact of the precision determination of oscillation parameters in the JUNO experiment on half-life predictions for neutrinoless double beta decay. We show that the solar neutrino mixing angle can be measured by JUNO with below 1% uncertainty. This implies in particular that the minimal value of the effective mass in the inverted mass ordering will be known essentially without uncertainty. We demonstrate that this reduces the range of half-life predictions in order to test this value by a factor of two. The remaining uncertainty is caused by nuclear matrix elements. This has important consequences for future double beta decay experiments that aim at ruling out the inverted mass ordering or the Majorana nature of neutrinos.

  2. Importance of neutrinoless double beta decay

    E-Print Network [OSTI]

    Utpal Sarkar

    2007-12-17

    A natural explanation for the smallness of the neutrino mass requires them to be Majorana particles violating lepton number by two units. Since lepton number violation can have several interesting consequences in particle physics and cosmology, it is of utmost importance to find out if there is lepton number violation in nature and what is its magnitude. The neutrinoless double beta decay experiment can answer these questions: if there is lepton number violation and if neutrinos are Majorana particles. In addition, the magnitude of neutrinoless double beta decay will constrain any other lepton number violating processes. This lepton number violation may also be relatd to the matter-antimatter asymmetry of the universe, dark matter and cosmological constant.

  3. Probing neutrinoless double beta decay with SNO+

    E-Print Network [OSTI]

    Evelina Arushanova; Ashley R. Back

    2015-05-01

    Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\

  4. Probing neutrinoless double beta decay with SNO+

    E-Print Network [OSTI]

    Arushanova, Evelina

    2015-01-01

    Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\

  5. JUNO and Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Ge, Shao-Feng

    2015-01-01

    We study the impact of the precision determination of oscillation parameters in the JUNO experiment on half-life predictions for neutrinoless double beta decay. We show that the solar neutrino mixing angle can be measured by JUNO with below 1% uncertainty. This implies in particular that the minimal value of the effective mass in the inverted mass ordering will be known essentially without uncertainty. We demonstrate that this reduces the range of half-life predictions in order to test this value by a factor of two. The remaining uncertainty is caused by nuclear matrix elements. This has important consequences for future double beta decay experiments that aim at ruling out the inverted mass ordering or the Majorana nature of neutrinos.

  6. Searches for very rare decays of kaons

    SciTech Connect (OSTI)

    Lang, K. [Univ. of Texas, Austin, TX (United States)

    1997-01-01

    The physics motivation for searches for very rare kaon decays, either forbidden or suppressed within the Standard Model, is briefly discussed. Simple arguments conclude that such searches probe possible new forces at a 200 TeV mass scale or constitute a precision test of the electroweak model. The examples of such process are decays of K{sub L}{sup 0} {yields} {mu} {sup {+-}}e{sup -+}, K{sup +} {yields} {pi}{sup +} {mu}{sup +} e{sup -}, K{sub L}{sup 0} {yields} {mu}{sup +} {mu}{sup -}, and K{sup +} {yields} {pi} {yields} {pi}{sup +}{nu}{bar {nu}}. We present the current experimental status and describe the new efforts to reach sensitivities down to one part in 10{sup 12}. The discussion is focused on the experimental program at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, where intense beams make such studies possible.

  7. {tau} decays and chiral perturbation theory

    SciTech Connect (OSTI)

    Colangelo, G.; Finkemeier, M.; Urech, R.

    1996-10-01

    In a small window of phase space, chiral perturbation theory can be used to make standard model predictions for {tau} decays into two and three pions. For {tau}{r_arrow}2{pi}{nu}{sub {tau}}, we give the analytical result for the relevant form factor {ital F}{sub {ital V}} up to two loops, then calculate the differential spectrum and compare with available data. For {tau}{r_arrow}3{pi}{nu}{sub {tau}}, we have calculated the hadronic matrix element to one loop. We discuss the decomposition of the three pion states into partition states and we give detailed predictions for the decay in terms of structure functions. We also compare with low energy predictions of meson dominance models. Overall, we find good agreement, but also some interesting discrepancies, which might have consequences beyond the limit of validity of chiral perturbation theory. {copyright} {ital 1996 The American Physical Society.}

  8. Mass determination in sequential particle decay chains

    E-Print Network [OSTI]

    Bryan Webber

    2009-09-12

    A simple method is proposed for determining the masses of new particles in collider events containing a pair of decay chains (not necessarily identical) of the form Z -> Y+1, Y -> X+2, X -> N+3, where 1,2 and 3 are visible but N is not. Initial study of a possible supersymmetric case suggests that the method can determine the four unknown masses in effectively identical chains with good accuracy from samples of a few tens of events.

  9. Neutrinoless Double Beta Decay and its "Inverse"

    E-Print Network [OSTI]

    Clemens A. Heusch; Peter Minkowski

    1996-11-18

    Recent considerations by these authors pointed out the attractive features which a search for the exchange of heavy Majorana neutrinos could have for solving the mass and the lepton number puzzles for all neutrinos, in TeV-level electron-electron scattering. In the present note, we show that, contrary to subsequently published arguments, non-observation of neutrinoless double beta decay has, to date, no bearing on the promise of this important task for future linear electron colliders.

  10. Neutrinoless Double Beta Decay in Particle Physics

    E-Print Network [OSTI]

    Werner Rodejohann

    2010-11-22

    Neutrinoless double beta decay is a process of fundamental importance for particle physics. It can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). We review its dependence on the neutrino parameters, its complementarity to other observables sensitive to neutrino mass, and emphasize its ability to distinguish different neutrino mass models. Then we discuss mechanisms different from light Majorana neutrino exchange, and show what can be learned from those and how they could be tested.

  11. Simulations of Alpha Wall Load in ITER. Final report

    SciTech Connect (OSTI)

    Carlsson, Johan

    2010-10-20

    The partially DOE funded International Thermonuclear Experimental Reactor (ITER) will produce massive amounts of energetic charged alpha particles, which are imperfectly confined by a strong magnetic field. The wall of the experiment is designed to withstand an estimated wall load from these fusion alpha particles, but the accuracy of this estimate needs to be improved to avoid potentially catastrophic surprises when the experiment becomes operational. We have added a more accurate, gyro-dynamic model of particle motion to the existing drift-dynamic model in the DELTA5D simulation software used for the project. We have also added the ability to load a detailed engineering model of the wall and use it in the simulations.

  12. Alpha Solarco`s Photovoltaic Concentrator Development program

    SciTech Connect (OSTI)

    Anderson, A.; Bailor, B.; Carroll, D.

    1995-10-01

    This report details the work done under Sandia`s Photovoltaic Concentrator Development contract, funded jointly by Alpha Solarco and the US Department of Energy. It discusses improvements made to the cell assembly and module design of Alpha Solarco`s point-focus, high-concentration photovoltaic module. The goals of this effort were to increase the module efficiency, reduce the manufacturing cost of the cell assembly, and increase product reliability. Redesign of the secondary optical element achieved a 4 percent increase in efficiency due to better cell fill factors and offtrack performance. New, lower cost materials were identified for the secondary optical element, the optical couple between the secondary optical element and the cell, and the cell assembly electrical insulator. Manufacturing process improvements and test equipment are also discussed.

  13. A background free double beta decay experiment

    E-Print Network [OSTI]

    Ioannis Giomataris

    2010-12-20

    We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.

  14. Double beta decays of {sup 106}Cd

    SciTech Connect (OSTI)

    Suhonen, Jouni [Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyvaeskylae (Finland)

    2011-12-16

    The two-neutrino (2{nu}2{beta}) and neutrinoless (0{nu}2{beta}) double beta decays of {sup 106}Cd are studied for the transitions to the ground state 0{sub gs}{sup +} and 0{sup +} and 2{sup +} excited states in {sup 106}Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation. Effective, G-matrix-derived nuclear forces are used in realistic single-particle model spaces. All the possible channels, {beta}{sup +}{beta}{sup +}, {beta}{sup +}EC, and ECEC, are discussed for both the 2{nu}2{beta} and 0{nu}2{beta} decays. The associated half-lives are computed and particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture (R0{nu}ECEC) process in {sup 106}Cd. The calculations of the present article constitute the thus far most complete and up-to-date investigation of the double-beta-decay properties of {sup 106}Cd.

  15. Delayed Nickel Decay in Gamma Ray Bursts

    E-Print Network [OSTI]

    G. C. McLaughlin; R. A. M. J. Wijers

    2002-05-19

    Recently observed emission lines in the X-ray afterglow of gamma ray bursts suggest that iron group elements are either produced in the gamma ray burst, or are present nearby. If this material is the product of a thermonuclear burn, then such material would be expected to be rich in Nickel-56. If the nickel remains partially ionized, this prevents the electron capture reaction normally associated with the decay of Nickel-56, dramatically increasing the decay timescale. Here we examine the consequences of rapid ejection of a fraction of a solar mass of iron group material from the center of a collapsar/hypernova. The exact rate of decay then depends on the details of the ionization and therefore the ejection process. Future observations of iron, nickel and cobalt lines can be used to diagnose the origin of these elements and to better understand the astrophysical site of gamma ray bursts. In this model, the X-ray lines of these iron-group elements could be detected in suspected hypernovae that did not produce an observable gamma ray burst due to beaming.

  16. Low Redshift Lyman Alpha absorbers and their Connection with Galaxies

    E-Print Network [OSTI]

    Simon L. Morris; Buell Jannuzi; Ray Weymann

    2001-08-08

    We review the ongoing debate about the relationship between low redshift Lyman Alpha absorbers and luminous galaxies. In particular, we discuss the difficulty of `assigning' a particular absorber to a particular galaxy, and consider methods of circumventing this problem. We also provide a status report on an ongoing project collecting more data to address this issue, and show some results for a close together pair of QSOs providing two adjacent lines of sight through the inter-galactic medium.

  17. A comparative study of DNA polymerase alpha isolation 

    E-Print Network [OSTI]

    Cernosek, Zina

    1987-01-01

    : 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... is dedicated to Patrick R. Kane for keeping a smile on my face throughout the long hours of research and writing. TABLE OF CONTENTS PAGE INTRODUCTION. MATERIALS AND METHODS. RESULTS 17 22 Purification of DNA polymerase isolation: Mechali et al. 22...

  18. Nuclear Reactions Important in Alpha-Rich Freezeouts

    E-Print Network [OSTI]

    G. C. Jordan IV; S. S. Gupta; B. S. Meyer; L. -S. The

    2002-11-08

    The alpha-rich freezeout from equilibrium occurs during the core-collapse explosion of a massive star when the supernova shock wave passes through the Si-rich shell of the star. The nuclei are heated to high temperature and broken down into nucleons and alpha particles. These subsequently reassemble as the material expands and cools, thereby producing new heavy nuclei, including a number of important supernova observables. In this paper we introduce two web-based applications. The first displays the results of a reaction-rate sensitivity study of alpha-rich freezeout yields. The second allows the interested reader to run paramaterized explosive silicon burning calculations in which the user inputs his own parameters. These tools are intended to aid in the identification of nuclear reaction rates important for experimental study. We then analyze several iron-group isotopes (59Ni, 57Co, 56Co, and 55Fe) in terms of their roles as observables and examine the reaction rates that are important in their production.

  19. State-of-the-Art Predictions for C-parameter and a Determination of alpha_s

    E-Print Network [OSTI]

    Andre H. Hoang; Daniel W. Kolodrubetz; Vicent Mateu; Iain W. Stewart

    2015-01-20

    The C-parameter event-shape distribution for e+e- annihilation into hadrons is computed in the framework of SCET including input from fixed-order perturbation theory. We calculate all missing ingredients for achieving N3LL resummation accuracy in the cross section, which is then matched onto O(alpha_s^3) fixed-order results. Hadronization power corrections are incorporated as a convolution with a nonperturbative shape function. Wide-angle soft radiation effects introduce an O(Lambda_QCD) renormalon ambiguity in the cross section, which we cure by switching to the Rgap short-distance scheme. We also include hadron mass effects, but find their effect is rather small. Performing fits to the tail of the C-parameter distribution for many center of mass energies we find that the strong coupling constant is alpha_s(mZ) = 0.1123 +-0.0015, with chi^2/dof=0.99.

  20. Neutron Interactions in the CUORE Neutrinoless Double Beta Decay Experiment

    SciTech Connect (OSTI)

    Dolinski, M J

    2008-09-24

    Neutrinoless double beta decay (0{nu}DBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0{nu}DBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0{nu}DBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0{nu}DBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0{nu}DBD of {sup 130}Te with a ton-scale array of unenriched TeO{sub 2} bolometers. By increasing mass and decreasing the background for 0{nu}DBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10{sup -6}. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0{nu}DBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, which can be produced underground both by ({alpha},n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE data to set an upper limit for the production of a 2529 keV gamma-ray from the {sup 126}Te(n,n{prime}{gamma}) reaction. This gamma-ray is a potential source of interference for the 0{nu}DBD peak. Based on this measurement, the contribution of this line to the background is expected to be negligible.

  1. Half-lives of Double $?^+$-decay with Two Neutrinos

    E-Print Network [OSTI]

    Yuejiao Ren; Zhongzhou Ren

    2015-01-07

    Nuclear double $\\beta ^-$-decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys. Rev. C89, 064603 (2014)]. However, double $\\beta ^+$-decay ($\\beta ^+\\beta^+)$ with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we perform a systematic analysis on the candidates of double $\\beta ^+$-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double $\\beta ^+$-decay and their half-lives are predicted according to the generalization of the systematic law to double $\\beta ^+$-decay. As far as we know, there is no theoretical result on double $\\beta ^+$-decay of nucleus $^{154}Dy$ and our result is the first prediction on this nucleus. This is also the first complete research on eight double $\\beta ^+$-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double $\\beta ^+$-decay in this article will be useful for future experimental search of double $\\beta ^+$-decay.

  2. Radiative-nonrecoil corrections of order {alpha}{sup 2}(Z{alpha})E{sub F} to the hyperfine splitting of muonium

    SciTech Connect (OSTI)

    Mondejar, Jorge; Piclum, Jan H.; Czarnecki, Andrzej [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7, Canada, and CERN Theory Division, CH-1211 Geneva 23 (Switzerland)

    2010-06-15

    We present results for the corrections of order {alpha}{sup 2}(Z{alpha})E{sub F} to the hyperfine splitting of muonium. We compute all the contributing Feynman diagrams in dimensional regularization and a general covariant gauge using a mixture of analytical and numerical methods. We improve the precision of previous results.

  3. PPPL-3145 -Preprint Date: October 1995, UC-420, 426, 427 Alpha-Physics and Measurement Requirements for ITER

    E-Print Network [OSTI]

    and control than existing heating systems such as NBI and ICRH. In addition, alpha particle heating and loss measurements. A comparison is made between alpha heating in ITER and NBI and ICRH heating systems in present in ITER requires about 300 MW of alpha particle heating power. Since the alpha particle creation rate

  4. BRIDGE: Branching Ratio Inquiry/Decay Generated Events

    E-Print Network [OSTI]

    Patrick Meade; Matthew Reece

    2007-10-24

    We present the manual for the program BRIDGE: Branching Ratio Inquiry/Decay Generated Events. The program is designed to operate with arbitrary models defined within matrix element generators, so that one can simulate events with small final-state multiplicities, decay them with BRIDGE, and then pass them to showering and hadronization programs. BRI can automatically calculate widths of two and three body decays. DGE can decay unstable particles in any Les Houches formatted event file. DGE is useful for the generation of event files with long decay chains, replacing large matrix elements by small matrix elements followed by sequences of decays. BRIDGE is currently designed to work with the MadGraph/MadEvent programs for implementing and simulating new physics models. In particular, it can operate with the MadGraph implementation of the MSSM. In this manual we describe how to use BRIDGE, and present a number of sample results to demonstrate its accuracy.

  5. Three-body decay of (6)Be 

    E-Print Network [OSTI]

    Grigorenko, L. V.; Wiser, T. D.; Mercurio, K.; Charity, R. J.; Shane, R.; Sobotka, L. G.; Elson, J. M.; Wuosmaa, A. H.; Banu, A.; McCleskey, M.; Trache, L.; Tribble, Robert E.; Zhukov, M. V.

    2009-01-01

    and, possibly, of the A = 6 isobars. DOI: 10.1103/PhysRevC.80.034602 PACS number(s): 23.50.+z, 23.20.En, 21.60.Gx, 27.20.+n I. INTRODUCTION Two-proton (2p) radioactivity was predicted by V. I. Goldansky in 1960 [1] as an exclusively quantum... in Fig. 1 that shows that the 5Li ground state (g.s.) is not fully accessible for sequential decay. Because the experimental discovery of 45Fe two-proton radioactivity in 2002 [2,3], this field has made fast progress. New cases of 2p radioactivity...

  6. Search for the rare decay Bs0??+?-

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

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; et al

    2010-10-01

    We present the results of a search for the flavor changing neutral current decay B0susing 6.1 fb-1 of pp? collisions at collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B0scandidates is consistent with background expectations. The resulting upper limit on the branching fraction is B (B0s ? ????) -8 at the 95% C.L. This limit is a factor of 2.4 better than that of the previous D0 analysis and the best limit to date.

  7. Neutrinoless double beta decay and QCD corrections

    E-Print Network [OSTI]

    Namit Mahajan

    2014-01-30

    We consider one loop QCD corrections and renormalization group running of the neutrinoless double beta decay amplitude focusing on the short-range part of the amplitude (without the light neutrino exchange) and find that these corrections can be sizeable. Depending on the operator under consideration, there can be moderate to large cancellations or significant enhancements. We discuss several specific examples in this context. Such large corrections will lead to significant shifts in the half-life estimates which currently are known to be plagued with the uncertainties due to nuclear physics inputs to the physical matrix elements.

  8. Rare b hadron decays at the LHC

    E-Print Network [OSTI]

    Blake, T; Hiller, G

    2015-01-01

    With the completion of Run~I of the CERN Large Hadron Collider, particle physics has entered a new era. The production of unprecedented numbers of heavy-flavoured hadrons in high energy proton-proton collisions allows detailed studies of flavour-changing processes. The increasingly precise measurements allow to probe the Standard Model with a new level of accuracy. Rare $b$ hadron decays provide some of the most promising approaches for such tests, since there are several observables which can be cleanly interpreted from a theoretical viewpoint. In this article, the status and prospects in this field are reviewed, with a focus on precision measurements and null tests.

  9. Search for ? mesons in ? lepton decay

    E-Print Network [OSTI]

    Baringer, Philip S.

    1997-02-01

    ¯m and Em the momentum and energy of the event. All charged tracks are assumed to be pions. @19# R.A. Fisher, Ann. Eugen. 7, 179 ~1936!. @20# B. Flury and H. Ridewyl, Multivariate Statistics, A Practical Approach ~New York, Chapman and Hall, 1988!. @21# S... of information on a possible four-quark state @C~1480!# with a mass 1480 MeV/c2 and JPC5122 @3,4# which decays into fp . Building on the work of Ref. @5#, Eidelman and Ivanchenko @6# estimate the branching fraction of t2!fp2n t assuming that the C~1480...

  10. Search for neutrinoless ? decays: ??e? and ????

    E-Print Network [OSTI]

    Baringer, Philip S.

    1997-04-01

    or mg and the tag side includes all standard t decays into one charged particle, any number of photons and at least one neutrino. The selection criteria are based on the studies of two Monte Carlo samples of 10 000 t pair events each. The Monte Carlo... these criteria are applied, 19.3% of eg and 36.2% of mg Monte Carlo events remain in the signal region. In addition, each candidate event must have exactly one photon separated by more than 20° from the closest charged track in the lepton hemisphere. This photon...

  11. No-neutrino double beta decay: more than one neutrino

    SciTech Connect (OSTI)

    Rosen, S.P.

    1983-01-01

    Interference effects between light and heavy Majorana neutrinos in the amplitude for no-neutrino double beta decay are discussed. The effects include an upper bound on the heavy neutrino mass, and an A dependence for the effective mass extracted from double beta decay. Thus the search for the no-neutrino decay mode should be pursued in several nuclei, and particularly in Ca/sup 48/, where the effective mass may be quite large.

  12. NEMO 3 double beta decay experiment: latest results

    E-Print Network [OSTI]

    A. S. Barabash

    2008-07-17

    The double beta decay experiment NEMO~3 has been taking data since February 2003. The aim of this experiment is to search for neutrinoless decay and investigate two neutrino double beta decay in seven different enriched isotopes ($^{100}$Mo,$^{82}$Se, $^{48}$Ca, $^{96}$Zr, $^{116}$Cd, $^{130}$Te and $^{150}$Nd). After analysis of the data corresponding to 693 days, no evidence for $0\

  13. Neutrinoless double beta decay search with the NEMO 3 experiment

    E-Print Network [OSTI]

    Irina Nasteva; for the NEMO 3 Collaboration

    2008-10-03

    The NEMO 3 experiment searches for neutrinoless double beta decay and makes precision measurements of two-neutrino double beta decay in seven isotopes. The latest two-neutrino half-life results are presented, together with the limits on neutrinoless half-lives and the corresponding effective Majorana neutrino masses. Also given are the limits obtained on neutrinoless double beta decay mediated by Rp-violating SUSY, right-hand currents and different Majoron emission modes.

  14. Neutrinoless double beta decay search with the NEMO 3 experiment

    SciTech Connect (OSTI)

    Nasteva, Irina [Particle Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2008-11-23

    The NEMO 3 experiment searches for neutrinoless double beta decay and makes precision measurements of two-neutrino double beta decay in seven isotopes. The latest two-neutrino half-life results are presented, together with the limits on neutrinoless half-lives and the corresponding effective Majorana neutrino masses. Also given are the limits obtained on neutrinoless double beta decay mediated by R{sub p}-violating SUSY, right-hand currents and different Majoron emission modes.

  15. Neutrinoless Double Beta Decay in Supersymmetric Seesaw model

    E-Print Network [OSTI]

    Tai-Fu Feng; Xue-Qian Li; Yan-An Luo

    2002-09-26

    Inspired by the recent HEIDELBERG-MOSCOW double beta decay experiment, we discuss the neutrinoless double beta decay in the supersymmetric seesaw model. Our numerical analysis indicates that we can naturally explain the data of the observed neutrinoless double beta decay, as well as that of the solar and atmospheric neutrino experiments with at least one Majorana-like sneutrino of middle energy scale in the model.

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

    E-Print Network [OSTI]

    John N. Bahcall; Hitoshi Murayama; Carlos Pena-Garay

    2004-04-08

    We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but next generation beta decay searches for a neutrino mass only set a mass upper limit, can we establish whether the mass hierarchy is normal or inverted? We base our answers on the expected performance of next generation neutrinoless double beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements.

  17. 75 years of double beta decay: yesterday, today and tomorrow

    E-Print Network [OSTI]

    A. S. Barabash

    2011-01-24

    In this report I will briefly review the motivation and history of double beta decay search since the first consideration of two neutrino process (2$\\beta(2\

  18. Searches for Leptonic B Decays at BaBar

    SciTech Connect (OSTI)

    Nelson, Silke; /SLAC

    2012-04-25

    Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.

  19. Search for New Physics in Rare Top Decays

    E-Print Network [OSTI]

    Pratishruti Saha

    2014-11-27

    Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the Standard Model, new-physics contributions of comparable magnitude may exist and yet go unnoticed because their impact on the total decay width is small. Hence it is interesting to probe rare top decays. This analysis focuses on the decay $t \\to b \\bar b c$. Useful observables are identified and prospects for measuring new-physics parameters are examined.

  20. Pion and muon decays beyond the standard model

    SciTech Connect (OSTI)

    Herczeg, P.

    1988-01-01

    We review and discuss the information provided by charged pion and muon decays on physics beyond the minimal standard model. 109 refs., 3 tabs.

  1. Neutron Interactions in the CUORE Neutrinoless Double Beta Decay...

    Office of Scientific and Technical Information (OSTI)

    Interactions in the CUORE Neutrinoless Double Beta Decay Experiment Dolinski, M J 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS;...

  2. What can we learn from neutrinoless double beta decay experiments...

    Office of Scientific and Technical Information (OSTI)

    beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements. Authors: Bahcall, John N. ; Murayama, Hitoshi ; Pena-Garay, Carlos...

  3. Annihilation diagrams in two-body nonleptonic decays of charmed...

    Office of Scientific and Technical Information (OSTI)

    FEYNMAN DIAGRAM; TWO-BODY PROBLEM; AXIAL VECTOR MESONS; KOBAYASHI-MASKAWA MATRIX; PSEUDOSCALAR MESONS; BASIC INTERACTIONS; BOSONS; CHARM PARTICLES; DECAY; DIAGRAMS;...

  4. CP violation for neutral charmed meson decays to CP eigenstates

    E-Print Network [OSTI]

    Dongsheng Du

    2006-11-06

    CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.

  5. Spectroscopy and Decay of $B$ Hadrons at the Tevatron

    SciTech Connect (OSTI)

    Paulini, Manfred

    2007-02-01

    The authors review recent results on heavy quark physics focusing on Run II measurements of B hadron spectroscopy and decay at the Tevatron. A wealth of new B physics measurements from CDF and D0 has been available. These include the spectroscopy of excited B states (B**, B**{sub s}) and the observation of the {Sigma}{sub b} baryon. The discussion of the decays of B hadrons and measurements of branching fractions focuses on charmless two-body decays of B {yields} h{sup +}h{sup -}. They report several new B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} decay channels.

  6. The Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Carmen Palomares

    2005-05-20

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to operate on the International Space Station (ISS). The aim of AMS is the direct detection of charged particles in the rigidity range from 0.5 GV to few TV to perform high statistics studies of cosmic rays in space and search for antimatter and dark matter. This will be possible because of the large geometrical acceptance, a very accurate energy determination and a very precise particle identification through redundant measurements of its energy, velocity and electric charge. AMS is scheduled to be placed on the ISS at the beginning of 2008 for a 3 year exposure.

  7. Magnetic interaction in oxygenated alpha Fe-phthalocyanines

    SciTech Connect (OSTI)

    Kuzmann, Ern?, E-mail: kuzmann@caesar.elte.hu; Homonnay, Zoltán; Horváth, Attila [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, 1512 Budapest (Hungary); Pechousek, Jiri; Cuda, Jan; Machala, Libor; Zoppellaro, Giorgio; Zboril, Radek [Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science Palacky University, 17. Listopadu 1192/12, 771 46 Olomouc (Czech Republic); Yin, Houping; Wei, Yen [Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States); Klencsár, Zoltán [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117 (Hungary); Kubuki, Shiro [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachi-Oji, Tokyo 192-0397 (Japan); Nath, Amar [Department of Chemistry, University of North Carolina, Asheville, NC 28804 (United States)

    2014-10-27

    Alpha iron phthalocyanines (?-FePc) oxygenated at low temperatures were investigated with the help of {sup 57}Fe Mössbauer spectroscopy, magnetization measurements (SQUID) and X-ray diffractometry (XRD). Mössbauer spectroscopy revealed that upon oxygenation of ?-FePc, new species were formed which could be associated with Fe{sup III}Pc oxygen adducts. Unexpectedly, magnetically split spectrum of oxygenated ?-FePc was observed below 20 K. In-field Mössbauer spectra in a 5 T external magnetic field at 5K and magnetization measurements indicate antiferromagnetic coupling in oxygenated ?-FePc.

  8. Strange quark mass and Lambda parameter by the ALPHA collaboration

    E-Print Network [OSTI]

    Marinkovic, Marina; Sommer, Rainer; Virotta, Francesco

    2011-01-01

    We determine f_K for lattice QCD in the two flavor approximation with non-perturbatively improved Wilson fermions. The result is used to set the scale for dimensionful quantities in CLS/ALPHA simulations. To control its dependence on the light quark mass, two different strategies for the chiral extrapolation are applied. Combining f_K and the bare strange quark mass with non-perturbative renormalization factors and step scaling functions computed in the Schroedinger Functional, we determine the RGI strange quark mass and the Lambda parameter in units of f_K.

  9. Strange quark mass and Lambda parameter by the ALPHA collaboration

    E-Print Network [OSTI]

    Marina Marinkovic; Stefan Schaefer; Rainer Sommer; Francesco Virotta

    2011-12-18

    We determine f_K for lattice QCD in the two flavor approximation with non-perturbatively improved Wilson fermions. The result is used to set the scale for dimensionful quantities in CLS/ALPHA simulations. To control its dependence on the light quark mass, two different strategies for the chiral extrapolation are applied. Combining f_K and the bare strange quark mass with non-perturbative renormalization factors and step scaling functions computed in the Schroedinger Functional, we determine the RGI strange quark mass and the Lambda parameter in units of f_K.

  10. Property:Iso3166Alpha2 | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc Jump to:Newberg,Energy LLCALLETE Inc d bGeothermalAreaApplDsc JumpAlpha2 Jump

  11. City of Alpha, Minnesota (Utility Company) | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,CammackFLIRChurch Point, Louisiana:Alpha, Minnesota (Utility Company) Jump

  12. Complete (O{sub 7},O{sub 8}) contribution to B{yields}X{sub s{gamma}} at O({alpha}{sub s}{sup 2})

    SciTech Connect (OSTI)

    Asatrian, H. M.; Ewerth, T.; Ferroglia, A.; Greub, C.; Ossola, G.

    2010-10-01

    We calculate the set of O({alpha}{sub s}{sup 2}) corrections to the branching ratio and to the photon energy spectrum of the decay process B{yields}X{sub s{gamma}} originating from the interference of diagrams involving the electromagnetic dipole operator O{sub 7} with diagrams involving the chromomagnetic dipole operator O{sub 8}. The corrections evaluated here are one of the elements needed to complete the calculations of the B{yields}X{sub s{gamma}} branching ratio at next-to-next-to-leading order in QCD. We conclude that this set of corrections does not change the central value of the standard model prediction for Br(B{yields}X{sub s{gamma}}) by more than 1%.

  13. Electrons from Muon Decay in Bound State

    E-Print Network [OSTI]

    Rashid M. Djilkibaev; Rostislav V. Konoplich

    2009-02-12

    We present results of a study of the muon decay in orbit (DIO) contribution to the signal region of muon - electron conversion. Electrons from DIO are the dominant source of background for muon - electron conversion experiments because the endpoint of DIO electrons is the same as the energy of electrons from elastic muon - electron conversion. The probability of DIO contribution to the signal region was considered for a tracker with Gaussian resolution function and with a realistic resolution function obtained in the application of pattern recognition and momentum reconstruction Kalman filter based procedure to GEANT simulated DIO events. It is found that the existence of non Gaussian tails in the realistic resolution function does not lead to a significant increase in DIO contribution to the signal region. The probability of DIO contribution to the calorimeter signal was studied in dependence on the resolution, assuming a Gaussian resolution function of calorimeter. In this study the geometrical acceptance played an important role, suppressing DIO contribution of the intermediate range electrons from muon decay in orbit.

  14. Dark matter from decaying topological defects

    SciTech Connect (OSTI)

    Hindmarsh, Mark [Helsinki Institute of Physics, Gustaf Hällströmin katu, P.O. Box 64, 00014 Helsinki University (Finland); Kirk, Russell; West, Stephen M., E-mail: m.b.hindmarsh@sussex.ac.uk, E-mail: russell.kirk.2008@live.rhul.ac.uk, E-mail: stephen.west@rhul.ac.uk [Dept. of Physics, Royal Holloway University of London, Egham Hill, Egham, Surrey, TW20 0EX (United Kingdom)

    2014-03-01

    We study dark matter production by decaying topological defects, in particular cosmic strings. In topological defect or ''top-down'' (TD) scenarios, the dark matter injection rate varies as a power law with time with exponent p?4. We find a formula in closed form for the yield for all p < 3/2, which accurately reproduces the solution of the Boltzmann equation. We investigate two scenarios (p = 1, p = 7/6) motivated by cosmic strings which decay into TeV-scale states with a high branching fraction into dark matter particles. For dark matter models annihilating either by s-wave or p-wave, we find the regions of parameter space where the TD model can account for the dark matter relic density as measured by Planck. We find that topological defects can be the principal source of dark matter, even when the standard freeze-out calculation under-predicts the relic density and hence can lead to potentially large ''boost factor'' enhancements in the dark matter annihilation rate. We examine dark matter model-independent limits on this scenario arising from unitarity and discuss example model-dependent limits coming from indirect dark matter search experiments. In the four cases studied, the upper bound on G? for strings with an appreciable channel into TeV-scale states is significantly more stringent than the current Cosmic Microwave Background limits.

  15. Performance of a large TeO2 crystal as a cryogenic bolometer in searching for neutrinoless double beta decay

    E-Print Network [OSTI]

    L. Cardani; L. Gironi; J. W. Beeman; I. Dafinei; Z. Ge; G. Pessina; S. Pirro; Y. Zhu

    2011-06-03

    Bolometers are ideal devices in the search for neutrinoless Double Beta Decay. Enlarging the mass of individual detectors would simplify the construction of a large experiment, but would also decrease the background per unit mass induced by alpha-emitters located close to the surfaces and background arising from external and internal gamma's. We present the very promising results obtained with a 2.13 kg TeO2 crystal. This bolometer, cooled down to a temperature of 10.5 mK in a dilution refrigerator located deep underground in the Gran Sasso National Laboratories, represents the largest thermal detector ever operated. The detector exhibited an energy resolution spanning a range from 3.9 keV (at 145 keV) to 7.8 keV (at the 2615 gamma-line of 208Tl) FWHM. We discuss the decrease in the background per unit mass that can be achieved increasing the mass of a bolometer.

  16. Elastic {alpha} scattering on {sup 112}Sn and {sup 124}Sn at astrophysically relevant energies

    SciTech Connect (OSTI)

    Galaviz, D.; Mohr, P.; Zilges, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Fueloep, Zs.; Gyuerky, Gy.; Mate, Z.; Somorjai, E. [ATOMKI, P.O. Box 51, H-4001 Debrecen (Hungary); Rauscher, T. [Departement fuer Physik und Astronomie, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

    2005-06-01

    The cross sections for the elastic scattering reactions {sup 112,124}Sn({alpha},{alpha}){sup 112,124}Sn at energies above and below the Coulomb barrier are presented and compared to predictions for global {alpha}-nucleus potentials. The high precision of the new data allows a study of the global {alpha}-nucleus potentials at both the proton- and neutron-rich sides of an isotopic chain. In addition, local {alpha}-nucleus potentials have been extracted for both nuclei and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction {sup 112}Sn({alpha},{gamma}){sup 116}Te at astrophysically relevant energies are presented and compared to experimental data.

  17. Size dependence in the stabilities and electronic properties of \\alpha-graphyne and its BN analogue

    E-Print Network [OSTI]

    Özçelik, V Ongun

    2013-01-01

    We predict the stabilities of \\alpha-graphynes and their boron nitride analogues(\\alpha-BNyne), which are considered as competitors of graphene and two-dimensional hexagonal BN. Based on first-principles plane wave method, we investigated the stability and structural transformations of these materials at different sizes using phonon dispersion calculations and ab-initio finite temperature, molecular dynamics simulations. Depending on the number of additional atoms in the edges between the corner atoms of the hexagons, n, both \\alpha-graphyne(n) and \\alpha-BNyne(n) are stable for even n, but unstable for odd n. \\alpha-graphyne(3) undergoes a structural transformation, where the symmetry of hexagons is broken. We present the structure optimized cohesive energies, electronic, magnetic and mechanical properties of stable structures. Our calculations reveal the existence of Dirac cones in the electronic structures of \\alpha-graphynes of all sizes, where the Fermi velocities decrease with increasing n. The electron...

  18. Bounds on R-parity violating supersymmetric couplings from leptonic and semileptonic meson decays

    SciTech Connect (OSTI)

    Dreiner, H. K.; Kraemer, M.; O'Leary, Ben [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany); S.U.P.A., School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom) and Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany)

    2007-06-01

    We present a comprehensive update of the bounds on R-parity violating supersymmetric couplings from lepton-flavor- and lepton-number-violating decay processes. We consider {tau} and {mu} decays as well as leptonic and semileptonic decays of mesons. We present several new bounds resulting from {tau}, {eta}, and kaon decays and correct some results in the literature concerning B meson decays.

  19. On the nature of H$\\alpha$ emitters at $z \\sim 2$ from the HiZELS survey: physical properties, Ly$\\alpha$ escape fraction, and main sequence

    E-Print Network [OSTI]

    Oteo, I; Ivison, R J; Smail, I; Best, P N; Cepa, J; Pérez-García, A M

    2015-01-01

    We present a detailed multi-wavelength study (from rest-frame UV to far-IR) of narrow-band (NB) selected, star-forming (SF) H$\\alpha$ emitters (HAEs) at $z \\sim 2.23$ taken from the High Redshift(Z) Emission Line Survey (HiZELS). We find that HAEs have similar SED-derived properties and colors to $sBzK$ galaxies and probe a well-defined portion of the SF population at $z \\sim 2$. This is not true for Ly$\\alpha$ emitters (LAEs), which are strongly biased towards blue, less massive galaxies (missing a significant percentage of the SF population). Combining our H$\\alpha$ observations with matched, existing Ly$\\alpha$ data we determine that the Ly$\\alpha$ escape fraction ($f_{\\rm esc}$) is low (only $\\sim$ 4.5\\% of HAEs show Ly$\\alpha$ emission) and decreases with increasing dust attenuation, UV continuum slope, stellar mass, and star formation rate (SFR). This suggests that Ly$\\alpha$ preferentially escapes from blue galaxies with low dust attenuation. However, a small population of red and massive LAEs is also ...

  20. The Lyman Alpha Forest within The Cosmic Web

    E-Print Network [OSTI]

    J. Richard Bond; James W. Wadsley

    1997-03-20

    Observations indicate galaxies are distributed in a filament-dominated web-like structure; classic examples are the Coma and Perseus-Pisces superclusters. Numerical experiments at high and low redshift of viable structure formation theories also show filament-dominance; in particular, the gasdynamical simulations of Lyman alpha clouds at redshifts 2-6 that we concentrate on here. We understand why this is so in terms of rare events (peak patches) in the medium and the web pattern of filaments that bridge the gaps between the peaks along directions defined by their (oriented) tidal fields. We present an overview of these ideas and their practical application in crafting high resolution well-designed simulations. We show the utility of this by taking a highly filamentary subvolume found in a galactic-scale simulation, compressing its important large scale features onto a handful of numbers defining galactic-scale peak-patch constraints, which are then used to construct constrained initial conditions for a higher resolution simulation appropriate for study of the Lyman alpha forest.

  1. Non-slow-roll dynamics in $\\alpha-$attractors

    E-Print Network [OSTI]

    Kumar, K Sravan; Moniz, Paulo Vargas; Das, Suratna

    2015-01-01

    In this paper we consider the $\\alpha-$attractor model and study inflation under a generalization of slow-roll dynamics. We follow the recently proposed Gong \\& Sasaki approach \\cite{Gong:2015ypa} of assuming $N=N\\left(\\phi\\right)$. We relax the requirement of inflaton potential flatness and consider a sufficiently steep one to support 60-efoldings. We find that this type of inflationary scenario predicts an attractor at $n_{s}\\approx0.967$ and $r\\approx5.5\\times10^{-4}$ which are very close to the predictions of the first chaotic inflationary model in supergravity (Goncharov-Linde model) \\cite{Goncharov:1983mw}. We show that even with non-slow-roll dynamics, the $\\alpha-$attractor model is compatible with any value of $r<0.1$. In addition, we emphasize that in this particular inflationary scenario, the standard consistency relation $\\left(r\\simeq-8n_{t}\\right)$ is significantly violated and we find an attractor for tensor tilt at $n_{t}\\approx-0.034$ as $r\\rightarrow0$. Any prominent detection of the ...

  2. The impact of alpha/Fe enhanced stellar evolutionary tracks on the ages of elliptical galaxies

    E-Print Network [OSTI]

    Daniel Thomas; Claudia Maraston

    2003-02-04

    We complement our study of alpha/Fe enhanced stellar population models of Lick absorption indices (Thomas et al. 2003) by comparing two sets of alpha/Fe enhanced models. In both models the impact on Lick indices due to alpha/Fe enhancement is accounted for through a modification of the stellar absorption line-strengths using the response functions of Tripicco & Bell (1995). One set of models, however, uses solar-scaled, the other alpha/Fe enhanced stellar evolutionary tracks. Since the alpha/Fe enhanced tracks are hotter than the solar-scaled ones (Salasnich et al. 2000), the correspondent stellar population models have slightly weaker metallic indices (i.e. Mgb, etc.) and stronger Balmer line indices (Hbeta) (Maraston et al 2003). Here we explore quantitatively the impact of this effect on the alpha/Fe ratios, metallicities and ages that are derived for elliptical galaxies. We find that the modest decrease of the metallic indices Mgb and balance each other, such that fully consistent alpha/Fe ratios are derived for stellar systems using alpha/Fe enhanced models with either solar-scaled or alpha/Fe enhanced stellar tracks. The decrease of the metallic indices and the increase of Hbeta conspire in a way that also consistent metallicities are obtained. The derived ages, instead, are significantly different. The inclusion of alpha/Fe enhanced stellar tracks leads to the derivation of ages as high as 30 Gyr for elliptical galaxies. For the same objects, ages not older than 15 Gyr are obtained, if alpha/Fe enhanced models using solar-scaled tracks are adopted. This may indicate that current stellar evolutionary models overestimate the bluing of stellar evolutionary tracks due to alpha/Fe enhanced chemical mixtures at super-solar metallicities.

  3. Quanta of Local Conformational Change: Conformons in alpha-helical proteins

    E-Print Network [OSTI]

    Victor Atanasov; Yasser Omar

    2010-01-08

    We propose the conformon as a quantum of conformational change for energy transfer in alpha-helical proteins. The underlying mechanism of interaction between the quantum of excitation and the conformational degrees of freedom is nonlinear and leads to solitary wave packets of conformational energy. The phenomenon is specific to alpha-helices and not to beta-sheets in proteins due to the three strands of hydrogen bonds constituting the alpha-helical backbone.

  4. Density-induced suppression of the alpha-particle condensate in nuclear matter and the structure of alpha cluster states in nuclei

    E-Print Network [OSTI]

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

    2008-01-21

    At low densities, with decreasing temperatures, in symmetric nuclear matter alpha-particles are formed, which eventually give raise to a quantum condensate with four-nucleon alpha-like correlations (quartetting). Starting with a model of alpha-matter, where undistorted alpha particles interact via an effective interaction such as the Ali-Bodmer potential, the suppression of the condensate fraction at zero temperature with increasing density is considered. Using a Jastrow-Feenberg approach, it is found that the condensate fraction vanishes near saturation density. Additionally, the modification of the internal state of the alpha particle due to medium effects will further reduce the condensate. In finite systems, an enhancement of the S state wave function of the c.o.m. orbital of alpha particle motion is considered as the correspondence to the condensate. Wave functions have been constructed for self-conjugate 4n nuclei which describe the condensate state, but are fully antisymmetrized on the nucleonic level. These condensate-like cluster wave functions have been successfully applied to describe properties of low-density states near the n alpha threshold. Comparison with OCM calculations in 12C and 16O shows strong enhancement of the occupation of the S-state c.o.m. orbital of the alpha-particles. This enhancement is decreasing if the baryon density increases, similar to the density-induced suppression of the condensate fraction in alpha matter. The ground states of 12C and 16O show no enhancement at all, thus a quartetting condensate cannot be formed at saturation densities.

  5. Measurement of the Internal Magnetic Field of Plasmas using an Alpha Particle Source

    SciTech Connect (OSTI)

    S.J. Zweben; D.S. Darrow; P.W. Ross; J.L. Lowrance; G. Renda

    2004-05-13

    The internal magnetic fields of plasmas can be measured under certain conditions from the integrated v x B deflection of MeV alpha particles emitted by a small radioactive source. This alpha source and large-area alpha particle detector would be located inside the vacuum vessel but outside the plasma. Alphas with a typical energy of 5.5 MeV (241Am) can reach the center of almost all laboratory plasmas and magnetic fusion devices, so this method can potentially determine the q(r) profile of tokamaks or STs. Orbit calculations, background evaluations, and conceptual designs for such a vxB (or ''AVB'') detector are described.

  6. A single-particle/single-cell microbeam based on an isotopic alpha source

    E-Print Network [OSTI]

    the alpha particles are emitted to 4p and an acceptance of 10 mrad lm for the ion op- tics (see below) we

  7. Alpha channeling with high-field launch of lower hybrid waves...

    Office of Scientific and Technical Information (OSTI)

    of a radial alpha particle birth gradient, this interaction can take the form of wave amplification rather than damping. While it is known that this amplification more...

  8. Analysis of alpha-induced reactions on $^{151}$Eu below the Coulomb barrier

    E-Print Network [OSTI]

    V. Avrigeanu; M. Avrigeanu

    2010-12-05

    Novel measurements of $(\\alpha,\\gamma)$ and $(\\alpha$,n) reaction cross sections on the target nucleus $^{151}$Eu, close to the reaction thresholds, support the setting up of recent parameters of the $\\alpha$-particle optical model potential below the Coulomb barrier. A better understanding of the $\\alpha$-particle optical potential at these energies leads to a statistical model analysis of additional partial cross sections that were formerly measured but not considered within the model analysis. On this basis we have tentatively assigned a modified $J^{\\pi}$=9$^-$ spin and parity to the 22.7-h isomer in $^{154}$Tb.

  9. Leptonic Decays of the Charged B Meson

    SciTech Connect (OSTI)

    Corwin, Luke A.; /Ohio State U.; ,

    2010-06-11

    The authors present a search for the decay B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} ({ell} = {tau}, {mu}, or e) in (458.9 {+-} 5.1) x 10{sup 6} {Upsilon}(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}X) is selected, and in the recoil a search for B{sup +} {yields} {ell}{sup +}{nu}{sub {ell}} signal is performed. The {tau} is identified in the following channels: {tau}{sup +} {yields} e{sup +}{nu}{sub e}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}{bar {nu}}{sub {tau}}, {tau}{sup +} {yields} {pi}{sup +}{bar {nu}}{sub {tau}}, and {tau}{sup +} {yields} {pi}{sup +}{pi}{sup 0}{bar {nu}}{sub {tau}}. The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. They determine from the dataset a preliminary measurement of {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.8 {+-} 0.1) x 10{sup -4}, which excludes zero at 2.4{sigma}, and f{sub B} = 255 {+-} 58 MeV. Combination with the hadronically tagged measurement yields {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (1.8 {+-} 0.6) x 10{sup -4}. They also set preliminary limits on the branching fractions at {Beta}(B{sup +} {yields} e{sup +}{nu}{sub e}) < 7.7 x 10{sup -6} (90% C.L.), {Beta}(B{sup +} {yields} {mu}{sup +}{nu}{sub {mu}}) < 11 x 10{sup -6} (90% C.L.), and {Beta}(B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) < 3.2 x 10{sup -4} (90% C.L.).

  10. $\\alpha_s$ determination at NNLO$^\\star$+NNLL accuracy from the energy evolution of jet fragmentation functions at low $z$

    E-Print Network [OSTI]

    d'Enterria, David

    2015-01-01

    The QCD coupling $\\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental $e^+e^-$ and deep-inelastic $e^\\pm$p jet data to our NNLO$^*$+NNLL predictions, allow us to obtain $\\alpha_s(m_{_{\\rm Z}})$ = 0.1205$\\pm$0.0010$^{+0.0022}_{-0.0000}$, in excellent agreement with the current world average determined using other methods at the same level of accuracy.

  11. Distribution of ranks of ?-decay half-lives

    E-Print Network [OSTI]

    Juan Miguel Campanario

    2010-11-21

    I studied the distribution of ranks of values of 2949 {\\beta}-decay half-lives according to an empirical beta law with two exponents. {\\beta}-decay half-life ranks showed good fit to a beta function with two exponents.

  12. Double Beta Decay and the Absolute Neutrino Mass Scale

    E-Print Network [OSTI]

    Carlo Giunti

    2003-08-20

    After a short review of the current status of three-neutrino mixing, the implications for the values of neutrino masses are discussed. The bounds on the absolute scale of neutrino masses from Tritium beta-decay and cosmological data are reviewed. Finally, we discuss the implications of three-neutrino mixing for neutrinoless double-beta decay.

  13. Mass Measurement Using Energy Spectra in Three-body Decays

    E-Print Network [OSTI]

    Agashe, Kaustubh; Kim, Doojin; Wardlow, Kyle

    2015-01-01

    In previous works we have demonstrated how the energy distribution of massless decay products in two body decays can be used to measure the mass of decaying particles. In this work we show how such results can be generalized to the case of multi-body decays. The key ideas that allow us to deal with multi-body final states are an extension of our previous results to the case of massive decay products and the factorization of the multi-body phase space. The mass measurement strategy that we propose is distinct from alternative methods because it does not require an accurate reconstruction of the entire event, as it does not involve, for instance, the missing transverse momentum, but rather requires measuring only the visible decay products of the decay of interest. To demonstrate the general strategy, we study a supersymmetric model wherein pair-produced gluinos each decay to a stable neutralino and a bottom quark-antiquark pair via an off-shell bottom squark. The combinatorial background stemming from the indi...

  14. DECAY HEAT CONDITIONS OF CURRENT AND NEXT GENERATION REACTORS 

    E-Print Network [OSTI]

    Choe, JongSoo 1985-

    2012-05-04

    the accident in Japan last year. Thus, decay heat must be considered in reactor design for safety. The research focused on decay heat conditions of current and next generation reactors. US-APWR, ABWR, VHTR, and ABR were modeled and simulated using the program...

  15. High precision measurements of Na-26 beta(-) decay 

    E-Print Network [OSTI]

    Grinyer, GF; Svensson, CE; Andreoiu, C.; Andreyev, AN; Austin, RAE; Ball, GC; Chakrawarthy, RS; Finlay, P.; Garrett, PE; Hackman, G.; Hardy, John C.; Hyland, B.; Iacob, VE; Koopmans, KA; Kulp, WD; Leslie, JR; Macdonald, JA; Morton, AC; Ormand, WE; Osborne, CJ; Pearson, CJ; Phillips, AA; Sarazin, F.; Schumaker, MA; Scraggs, HC; Schwarzenberg, J.; Smith, MB; Valiente-Dobon, JJ; Waddington, JC; Wood, JL; Zganjar, EF.

    2005-01-01

    High-precision measurements of the half-life and beta-branching ratios for the beta(-) decay of Na-26 to Mg-26 have been measured in beta-counting and gamma-decay experiments, respectively. A 4 pi proportional counter and fast tape transport system...

  16. Correlated two-proton decay from (10)C 

    E-Print Network [OSTI]

    Mercurio, K.; Charity, R. J.; Shane, R.; Sobotka, L. G.; Elson, J. M.; Famiano, M.; Wuosmaa, A. H.; Banu, A.; Fu, C.; Trache, L.; Tribble, Robert E.; Mukhamedzhanov, A. M.

    2008-01-01

    and for a newly found level at E* = 8.4 MeV. A state at E* = 6.57 MeV is shown to undergo two-proton decay to (8)Be(g.s.) with strong p-p correlations consistent with the (1)S phase shift. Based on the lack of such correlations for other two-proton decays...

  17. Double beta decay to the excited states: experimental review

    E-Print Network [OSTI]

    A. S. Barabash

    2007-10-11

    A brief review on double beta decay to excited states of daughter nuclei is given. The ECEC(ov) transision to the excited states are discussed in association with a possible enhancement of the decay rate by several orders of magnitude.

  18. First search for CP violation in tau lepton decay

    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.

    1998-11-01

    We have performed the first search for CP violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic...

  19. Patterns in Offender Distance Decay and the Geographic Profiling Problem.

    E-Print Network [OSTI]

    O'Leary, Michael

    Patterns in Offender Distance Decay and the Geographic Profiling Problem. Mike O'Leary Towson University 2010 Fall Western Section Meeting Los Angeles, CA October 9-10, 2010 Mike O'Leary (Towson Department for his assistance. Mike O'Leary (Towson University) Offender Distance Decay October 9, 2010 2

  20. Patterns in Offender Distance Decay and the Geographic Profiling Problem.

    E-Print Network [OSTI]

    O'Leary, Michael

    Patterns in Offender Distance Decay and the Geographic Profiling Problem. Mike O'Leary Towson University 2011 Crime Mapping Conference Miami, FL October 19-21, 2011 Mike O'Leary (Towson University Department for his assistance. Mike O'Leary (Towson University) Offender Distance Decay October 21, 2011 2