WorldWideScience

Sample records for cap alpha decay

  1. Bremsstrahlung in $\\alpha$ Decay

    CERN Document Server

    Takigawa, N; Hagino, K; Ono, A; Brink, D M

    1999-01-01

    A quantum mechanical analysis of the bremsstrahlung in $\\alpha$ decay of $^{210}$Po is performed in close reference to a semiclassical theory. We clarify the contribution from the tunneling, mixed, outside barrier regions and from the wall of the inner potential well to the final spectral distribution, and discuss their interplay. We also comment on the validity of semiclassical calculations, and the possibility to eliminate the ambiguity in the nuclear potential between the alpha particle and daughter nucleus using the bremsstrahlung spectrum.

  2. Laser-assisted {alpha} decay

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda Cortes, Hector Mauricio; Palffy, Adriana; Keitel, Christoph H. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Popruzhenko, Sergey [Moscow State Engineering Physics Institute (Russian Federation)

    2012-07-01

    The spontaneous emission of alpha particles by unstable nuclei was one of the first physical processes to be described by quantum tunneling of a quasistationary state, i.e. a long-lived state. The development of new powerful coherent light sources opens the possibility to study the direct interaction between strong laser fields and atomic nuclei, assisting the tunneling of the {alpha} particle through the nuclear barrier. In this work we investigate for the first time the effect of strong laser fields on the tunneling and {alpha} particle emission of several medium-mass and heavy nuclei. To this end we make use of the formalism we have developed starting from the well-known Strong-Field Approximation and its complex trajectories formulation to describe the laser-assisted decay of quasistationary states [1]. The effect of a static as well as optical and X-ray monochromatic fields on the {alpha} decay lifetimes and {alpha} particle emission spectra is determined. We find that even at strong intensities, the laser-induced acceleration of the {alpha} decay is negligible, and only the spectra are significantly changed by the laser field. In particular, for optical fields, high laser intensities can lead to rescattering of the {alpha} particle off the daughter nucleus.

  3. Decay properties of /sup 186/Pb and the lead alpha-decay rate anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Toth, K.S.; Ellis-Akovali, Y.A.; Bingham, C.R.; Moltz, D.M.; Carter, H.K.; Mlekodaj, R.L.; Spejewski, E.H.; Sousa, D.C.

    1984-01-01

    Alpha-decay transitions between ground states of doubly-even nuclei are taken to represent unhindered decays. Reduced widths for these s-wave transitions behave in a regular fashion as a function of both neutron and atomic number. They are largest for nuclei two or four particles beyond a closed shell (with sharp minima at the shell) and they then decrease as the next closure is approached. The s-wave widths for /sup 186/ /sup 188/ /sup 190/ /sup 192/Pb, however, have been reported to behave anomalously, i.e., they purportedly increase by a factor of 30 between /sup 186/Pb (N = 104) and /sup 192/Ob (N = 110) instead of decreasing as one nears N = 126. Theoretical calculations have not reproduced this unusual behavior. The (electron-capture (EC) + ..beta../sup +/) strengths were deduced from K x-ray intensities. A number of corrections are involved in such determinations. We undertook the investigation of the (EC + ..beta../sup +/) decay schemes of these neutron-deficient lead isotopes, in conjunction with studies of their ..cap alpha..-decay properties, to obtain more reliable ..cap alpha..-branching ratios. Herein we present new information on /sup 186/Pb and discuss the partial ..cap alpha.. half-lives for /sup 192/Pb, /sup 190/Pb, /sup 188/Pb, and /sup 186/Pb together with ..cap alpha..-decay rates for even-even nuclei with Z greater than or equal to 78.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, W.D. (ed.)

    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.

  5. Trafficking of. cap alpha. -L-fucosidase in lymphoid cells

    Energy Technology Data Exchange (ETDEWEB)

    DiCioccio, R.A.; Brown, K.S.

    1987-05-01

    The quantity of ..cap alpha..-L-fucosidase in human serum is determined by heredity. The mechanism controlling levels of the enzyme in serum is unknown. To investigate this, lymphoid cell lines derived from individuals with either low, intermediate or high ..cap alpha..-L-fucosidase in serum were established. Steady state levels of extracellular ..cap alpha..-L-fucosidase protein and activity overlapped among the cell lines. Thus, in vivo serum phenotypes of ..cap alpha..-L-fucosidase are not adequately expressed in this system. ..cap alpha..-L-Fucosidase was also metabolically labelled with /sup 35/S-methionine, immunoprecipitated, and examined by SDS-PAGE. Cells pulse-labelled from 0.25-2 h had a major intracellular form of enzyme (Mr = 58,000). Cells pulsed for 1.5 h and chased for 21 h with unlabeled methionine had an intracellular form of Mr = 60,000 and an extracellular form of Mr = 62,000. Cells treated with chloroquine had only the 58,000-form both intra- and extra-cellularly. Moreover, chloroquine did not effect the quantitative distribution of ..cap alpha..-L-fucosidase between cells and medium. In fibroblasts, chloroquine enhanced the secretion of newly made lysosomal enzymes and blocked the processing of intercellular enzyme forms from a higher to a lower molecular mass. Thus, there are trafficking differences between ..cap alpha..-L-fucosidase in lymphoid cells and lysosomal enzymes in fibroblasts. This suggests that alternative targeting mechanisms for lysosomal enzymes exist in these cells.

  6. Inflaton Decay in an Alpha Vacuum

    CERN Document Server

    Naidu, S; Naidu, Siddartha; Holman, Richard

    2004-01-01

    We study the alpha vacua of de Sitter space by considering the decay rate of the inflaton field coupled to a scalar field placed in an alpha vacuum. We find an {\\em alpha dependent} Bose enhancement relative to the Bunch-Davies vacuum and, surprisingly, no non-renormalizable divergences. We also consider a modified alpha dependent time ordering prescription for the Feynman propagator and show that it leads to an alpha independent result. This result suggests that it may be possible to calculate in any alpha vacuum if we employ the appropriate causality preserving prescription.

  7. Alpha decay favoured isotopes of some superheavy nuclei: Spontaneous fission versus alpha decay

    CERN Document Server

    Kiren, O V; Bubbly, S G

    2013-01-01

    Spontaneous fission and alpha decay are the main decay modes for superheavy nuclei. The superheavy nuclei which have small alpha decay half-life compared to spontaneous fission half-life will survive fission and can be detected in the laboratory through alpha decay. We have studied the alpha decay half-life and spontaneous half-life of some superheavy elements in the atomic range Z = 100-130. Spontaneous fission half-lives of superheavy nuclei have been calculated using the phenomenological formula and the alpha decay half-lives using Viola-Seaborg-Sobiczewski formula (Sobiczewski et al. 1989), semi empirical relation of Brown (1992) and formula based on generalized liquid drop model proposed by Dasgupta-Schubert and Reyes (2007). The results are reported here.

  8. Mechanism of radiation graft of methyl-. cap alpha. -fluoroacrylate and. cap alpha. ,. beta. ,. beta. -trifluorostyrene on perfluorinated copolymer. [Cobalt 60

    Energy Technology Data Exchange (ETDEWEB)

    Ivankin, A.N.; Tevlina, A.S.; Zagorets, P.A. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1983-04-01

    The kinetics of radiation-induced graft copolymerization of methyl-..cap alpha..-fluoroacrylate and ..cap alpha.., ..beta.., ..beta..-trifluorostyrene to perfluorinated copolymer of hexafluoropropylene with tetrafluoroethylene has been studied. The orders of the grafting reaction towards the monomer and dose rate as well as the values of rate constants of radiation-induced grafting at various temperatures were determined, the effective activation energy of grafting (20.6 kJ/mol) was calculated. The kinetic scheme of elementary acts of radiation-induced graft copolymerization is discussed.

  9. Alpha Decay, Shell Structure, and New Elements

    Institute of Scientific and Technical Information of China (English)

    PENZhong-Zhou; TAIFei; SHENWen-Qing

    2003-01-01

    We systematically analyze the experimental data of alpha decay in even-even heavy nuclei far from stability and find that the Geiger-Nuttall law brea~s for an isotopic chain when its neutron number is across a marc number or there is a deformed subshell. This break can be used to identify new magic numbers of superheavy nuclei. It is also discovered that there is a new linear relation between the logarithm of half-life and the reciprocal of the square root of decay energy for N = 126 and N = 152 isotones. It could be a new law of alpha decay for nuclei with magic neutron numbers but the physics behind it is to be explored. The significance of these researches for the search of new elements is discussed.

  10. Alpha Decay, Shell Structure, and New Elements

    Institute of Scientific and Technical Information of China (English)

    REN Zhong-Zhou; TAI Fei; SHEN Wen-Qing

    2003-01-01

    We systematically analyze the experimental data of alpha decay in even-even heavy nuclei far from stabilityand find that the Geiger-Nuttall law breaks for an isotopic chain when its neutron number is across a magic numberor there is a deformed subshell. This break can be used to identify new magic numbers of superheavy nuclei. It is alsodiscovered that there is a new linear relation between the logarithm of half-life and the reciprocal of the square root ofdecay energy for N = 126 and N = 152 isotones. It could be a new law of alpha decay for nuclei with magic neutronnumbers but the physics behind it is to be explored. The significance of these researches for the search of new elementsis discussed.

  11. Alpha decay of {sup 181}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Henderson, D.J.; Hermann, R. [and others

    1995-08-01

    The {alpha}-decay energy of {sup 181}Pb was measured as 7211(10) keV and 7044(15). In the first study the isotope was produced in {sup 90}Zr bombardments of {sup 94}Mo and, after traversing a velocity filter, implanted in a position-sensitive Si detector; no half life for {sup 181}Pb was reported. In the second study the isotope was produced in {sup 40}Ca bombardments of {sup 144}Sm and transported to a position in front of a Si(Au) surface barrier detector with a fast He-gas-jet capillary system; an estimate of 50 ms was determined for the {sup 181}Pb half life. Recently we investigated {sup 181}Pb {alpha} decay at ATLAS as part of a survey experiment in which a l-pnA beam of 400-MeV {sup 92}Mo was used to irradiate targets of {sup 89}Y, {sup 90,92,94}Zr, and {sup 92}Mo to examine yields for one- and two-nucleon evaporation products from symmetric cold-fusion reactions. Recoiling nuclei of interest were passed through the Fragment Mass Analyzer and implanted in a double-sided silicon strip detector for {alpha}-particle assay. With the {sup 90}Zr target we observed a group at 7065(20) keV which was correlated with A = 181 recoils and had a half life of 45(20) ms. Our new results for {sup 181}Pb therefore agreed with those of the second study. There was no indication in the {sup 90}Zr + {sup 92}Mo data of the 7211(10)-keV {alpha} particles seen by Keller et al. The interested reader is referred to the 1993 atomic mass evaluation wherein the input {alpha}-decay energies and resultant masses of the light Pb isotopes (including {sup 181}Pb) are discussed.

  12. alpha-nucleus potentials, alpha-decay half-lives, and shell closures for superheavy nuclei

    OpenAIRE

    Mohr, Peter

    2006-01-01

    Systematic alpha-nucleus folding potentials are used to analyze alpha-decay half-lives of superheavy nuclei. Preformation factors of about several per cent are found for all nuclei under study. The systematic behavior of the preformation factors and the volume integrals of the potentials allows to predict alpha-decay energies and half-lives for unknown nuclei. Shell closures can be determined from measured alpha-decay energies using the discontinuity of the volume integral at shell closures. ...

  13. Radioimmunoassay determination of decreased amounts of. cap alpha. -L-fucosidase protein in fucosidosis

    Energy Technology Data Exchange (ETDEWEB)

    Andrews-Smith, G.L.; Alhadeff, J.A. (California Univ., San Diego, La Jolla (USA). Dept. of Neurosciences)

    1982-03-15

    Purified human liver ..cap alpha..-L-fucosidase (EC 3.2.1.51) has been radioiodinated by a chloramine-T procedure to a specific activity of 3.7 x 10/sup 6/ dpm/..mu..g protein without altering its apparent Michaelis constant for the 4-methylumbelliferyl substrate. This /sup 125/I-labeled ..cap alpha..-L-fucosidase has been used in development of a competitive binding radioimmunoassay for ..cap alpha..-L-fucosidase which can detect 1-2 ng of enzyme protein and has been employed to quantify the amount of ..cap alpha..-L-fucosidase protein in the liver and spleen from a patient with fucosidosis. Less than 1% of the normal amount of ..cap alpha..-L-fucosidase protein is present suggesting that normal amounts of catalytically inactive ..cap alpha..-L-fucosidase are not found in this disease.

  14. Concept of a (1-. cap alpha. ) performance confidence interval

    Energy Technology Data Exchange (ETDEWEB)

    Leong, H.H.; Johnson, G.R.; Bechtel, T.N.

    1980-01-01

    A multi-input, single-output system is assumed to be represented by some model. The distribution functions of the input and the output variables are considered to be at least obtainable through experimental data. Associated with the computer response of the model corresponding to given inputs, a conditional pseudoresponse set is generated. This response can be constructed by means of the model by using the simulated pseudorandom input variates from a neighborhood defined by a preassigned probability allowance. A pair of such pseudoresponse values can then be computed by a procedure corresponding to a (1-..cap alpha..) probability for the conditional pseudoresponse set. The range defined by such a pair is called a (1-..cap alpha..) performance confidence interval with respect to the model. The application of this concept can allow comparison of the merit of two models describing the same system, or it can detect a system change when the current response is out of the performance interval with respect to the previously identified model. 6 figures.

  15. ACTH and. cap alpha. -melanotropin in central temperature control

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, J.M.; Glyn, J.R.; Zimmer, J.A.

    1981-11-01

    Adrenocorticotropin (ACTH) and ..cap alpha..-melanotropin (..cap alpha..-MSH) occur in brain tissue known to be important to temperature control. These peptides cause hypothermia if they are injected centrally in sufficient doses, but they do not act on the central set point of temperature control. Instead they appear to inhibit central pathways for heat conservation and production. In addition to their hypothermic capability, these peptides are antipyretic when given centrally in doses that have no effect on normal body temperature. ACTH has previously been associated with fever reduction in both clinical and experimental studies, and it may be that endogenous central ACTH is important for limitation of maximal fever. The hypothermic and antipyretic effects of ACTH do not depend on stimulation of the adrenal cortex because they are also observed in adrenalectomized rabbits. Nor is the antipyretic effect limited to the rabbit inasmuch as a comparable effect has been demonstrated in the squirrel monkey. The two peptides may be involved in central mediation of normal thermoregulation and fever, perhaps limiting the febrile response and other rises in body temperature by acting as neurotransmitters or neuromodulators in central thermoregulatory pathways.

  16. Study of /sup 3/H+. cap alpha. and /sup 3/He+. cap alpha. elastic scattering in a state with zero orbital angular momentum

    Energy Technology Data Exchange (ETDEWEB)

    Chopovskii, L. L.

    1988-12-01

    An asymptotic wave function of the relative motion of clusters at zero interaction energy is derived in the oscillator representation. The set of equations of the algebraic version of the resonating-group method (RGM) is transformed to the zero-energy limit of the relative cluster motion. The /sup 3/H+..cap alpha.. and /sup 3/He+..cap alpha.. scattering lengths are calculated in the single-channel RGM variant on the basis of the derived equations. The possibility of experimentally observing large scattering lengths for light charged clusters is predicted, viz., /similar to/10--23 F in the /sup 3/H+..cap alpha.. channel and /similar to/30--82 F in the /sup 3/He+..cap alpha.. channel.

  17. Alpha decay by cubic plus Yukawa plus exponential model

    International Nuclear Information System (INIS)

    The half life of alpha decay in some nuclei by using cubic plus Yukawa plus exponential model (CYCM) of Shanmugam and Kamalaharan is calculated in this project and compared with the available experimental values

  18. Deletional rearrangement in the human T-cell receptor. cap alpha. -chain locus

    Energy Technology Data Exchange (ETDEWEB)

    de Villartay, J.P.; Lewis, D.; Hockett, R.; Waldmann, T.A.; Korsmeyer, S.J.; Cohen, D.I.

    1987-12-01

    The antigen-specific receptor on the surface of mature T lymphocytes is a heterodimer consisting of polypeptides termed ..cap alpha.. and ..beta... In the course of characterizing human T-cell tumors with an immature (CD4/sup -/, CD8/sup -/) surface phenotype, the authors detected a 2-kilobase ..cap alpha..-related transcript. Analysis of cDNA clones corresponding to this transcript established that a genetic element (which they call TEA, for T early ..cap alpha..) located between the ..cap alpha..-chain variable- and joining-region genes had been spliced to the ..cap alpha.. constant region. The TEA transcript is present early in thymocyte ontogeny, and its expression declines during T-cell maturation. More important, the TEA area functions as an active site for rearrangement within the ..cap alpha.. gene locus. Blot hybridization of restriction enzyme-digested DNA with a TEA probe revealed a narrowly limited pattern of rearrangement in polyclonal thymic DNA, surprisingly different from the pattern expected for the mature ..cap alpha.. gene with its complex diversity. These DNA blots also showed that TEA is generally present in the germ-line configuration in cells expressing the ..gamma..delta heterodimeric receptor and is deleted from mature (..cap alpha beta..-expressing) T-lymphocyte tumors and lines. Moreover, the TEA transcript lacked a long open reading frame for protein but instead possessed multiple copies of a repetitive element resembling those utilized in the heavy-chain class switch of the immunoglobulin genes. The temporal nature of the rearrangements and expression detected by TEA suggests that this recombination could mediate a transition between immature (..gamma..delta-expressing) T cells and mature (..cap alpha beta..-expressing) T cells.

  19. Structure of. cap alpha. -phase in two-phase titanium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, V.N.; Ivasishin, O.M.; Svechnikov, V.L. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)

    1982-08-01

    The structure of ..cap alpha..-phase in ..beta..-annealed titanium alloys VT 6 and VT 23 and its changes on heating up to ..cap alpha..+..beta.. ..-->.. ..beta.. transformation temperatures with accelerated cooling is studied. An assumption is made that the observed peculiarities of the residual ..cap alpha..-phase structure in alloys after such treatment are the consequence of the relaxation of interphase stresses resulting from a partial polymorphic transformation while the relaxation mechanism is determined by the alloying degree and initial alloy morphology.

  20. Unified approach to alpha decay calculations

    Indian Academy of Sciences (India)

    C S Shastry; S M Mahadevan; K Aditya

    2014-05-01

    With the discovery of a large number of superheavy nuclei undergoing decay through emissions, there has been a revival of interest in decay in recent years. In the theoretical study of decay the -nucleus potential, which is the basic input in the study of -nucleus systems, is also being studied using advanced theoretical methods. In the light of these, theWentzel–Kramers–Brillouin (WKB) approximation method often used for the study of decay is critically examined and its limitations are pointed out. At a given energy, the WKB expression uses barrier penetration formula for the determination of the transmission coefficient. This approach utilizes the -nucleus potential only at the barrier region and ignores it elsewhere. In the present era, when one has more precise experimental information on decay parameters and better understanding of -nucleus potential, it is desirable to use a more precise method for the calculation of decay parameters. We describe the analytic -matrix (SM) method which gives a procedure for the calculation of decay energy and mean life in an integrated way by evaluating the resonance pole of the -matrix in the complex momentum or energy plane. We make an illustrative comparative study of WKB and -matrix methods for the determination of decay parameters in a number of superheavy nuclei.

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

    CERN Document Server

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

    2013-01-01

    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.

  2. $\\alpha_{s}$ from the (revised) ALEPH data for $\\tau$ decay

    CERN Document Server

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

    2014-01-01

    We present a new analysis of $\\alpha_s$ from hadronic $\\tau$ decays based on the recently revised ALEPH data. The analysis is based on a strategy which we previously applied to the OPAL data. We critically compare our strategy to the one traditionally used and comment on the main differences. 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, $\\alpha_s(m_\\tau^2)=0.319\\pm 0.012$, as the most reliable results for $\\alpha_s$ from $\\tau$ decays currently available.

  3. Improved parametrization of the unified model for alpha decay and alpha capture

    CERN Document Server

    Denisov, V Yu; Sedykh, I Yu

    2015-01-01

    The updated data for the ground-state-to-ground-state alpha-transition half-lives in 401 nuclei and the alpha capture cross sections of 40Ca, 44Ca, 59Co, 208Pb and 209Bi are well described in the framework of the unified model for alpha-decay and alpha-capture. The updated values of the alpha decay half-lives, the binding energies of nuclei, the spins of parent and daughter nuclei, and the surface deformation parameters are used for the reevaluation of the model parameters. The data for the ground-state-to-ground-state alpha-decay half-lives are also well described by the empirical relationships.

  4. Alpha-particle decays from excited states in 24Mg

    Institute of Scientific and Technical Information of China (English)

    LIOTTA; R; J

    2011-01-01

    Using a cluster model based on the Woods-Saxon potential, alpha-particle decays from excited states in 24Mg have been system atically investigated. Calculations can in general reproduce experimental data, noticing the fact that the preformation factor P of alpha particle in alpha-decaying nuclei is of order from 100 to 10?2. This can be the evidence for the α+20Ne structure in 24Mg. Meanwhile, the results also show the existence of other configurations, such as 16O+2α. Since the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster (α particle), our results could serve as a guide to experimental spin assignments.

  5. Regulation of the synthesis of barley aleurone. cap alpha. -amylase by gibberellic acid and calcium ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.L.; Carbonell, J.

    1984-09-01

    The effects of gibberellic acid (GA/sub 3/) and calcium ions on the production of ..cap alpha..-amylase and acid phosphatase by isolated aleurone layers of barley (Hordeum vulgare L. cv Himalaya) were studied. Aleurone layers not previously exposed to GA/sub 3/ or CA/sup 2 +/ show qualitative and quantitative changes in hydrolase production following incubation in either GA/sub 3/ or CA/sup 2 +/ or both. In cubation in H/sub 2/O or CA/sup 2 +/ results in the production of low levels of ..cap alpha..-amylase or acid phosphatase. The addition of GA/sub 3/ to the incubation medium causes 10- to 20-fold increase in the amounts of these enzymes released from the tissue, and addition of CA/sup 2 +/ at 10 millimolar causes a further 8- to 9-fold increase in ..cap alpha..-amylase release and a 75% increase in phosphatase release. Production of ..cap alpha..-amylase isoenzymes is also modified by the levels of GA/sub 3/ and CA/sup 2 +/ in the incubation medium. ..cap alpha..-amylase 2 is produced under all conditions of incubation, while ..cap alpha..-amylase 1 appears only when layers are incubated in GA/sub 3/ or GA/sub 3/ plus CA/sup 2 +/. The synthesis of ..cap alpha..-amylases 3 and 4 requires the presence of both GA/sub 3/ and CA/sup 2 +/ in the incubation medium. Laurell rocket immunoelectrophoresis shows that two distinct groups of ..cap alpha..-amylase antigens are present in incubation media of aleurone layers incubated with both GA/sub 3/ and CA/sup 2 +/, while only one group of antigens is found in media of layers incubated in GA/sub 3/ alone. Strontium ions can be substituted for CA/sup 2 +/ in increasing hydrolase production, although higher concentrations of Sr/sup 2 +/ are requried for maximal response. We conclude that GA/sub 3/ is required for the production of ..cap alpha..-amylase 1 and that both GA/sub 3/ and either CA/sup 2 +/ or Sr/sup 2 +/ are required for the production of isoenzymes 3 and 4 of barley aleurone ..cap alpha..-amylase. 22 references, 8

  6. Comparison of semiempirical formulae for alpha decay half-lives

    International Nuclear Information System (INIS)

    The semiempirical relationships given by Froeman, Wapstra et al., Viola and Seaborg, Hornshoj et al., Taagepera and Nurmia, Keller and Munzel for alpha decay half-lives are compared with experimental results and with a new formula derived by the authors form the fission theory of alpha decay in even-even, odd-even, even-odd and odd-odd nuclei. By taking into consideration the shell effects, the new formula allows one to obtain a better agreement with experimental data, even in the neighbourhood of the magic numbers

  7. A simple approach to $\\alpha$-decay fine structure

    CERN Document Server

    Delion, D S; Liotta, R J; Wyss, R

    2016-01-01

    We propose a simple method to evaluate $\\alpha$-transition rates to low-lying excited states in even-even nuclei. For this a realistic $\\alpha$-daughter double folding interaction is approximated by a parabola in the region where the decay process takes place. This allows us to evaluate the penetration probability analytically. The main experimental features of branching ratios to excited states are reproduced by this simple approach.

  8. Theoretical Study on Alpha-Decay Chains of 294117 and 293117

    Institute of Scientific and Technical Information of China (English)

    SHENG Zong-Qiang; REN Zhong-Zhou

    2011-01-01

    The newly synthesized element 117 and its alpha-decay chains are systematically investigated in the framework of the relativistic mean field theory with parameter sets NL-Z2 and TMA.The ground-state properties of the superheavy nuclei on the alpha-decay chains of 294117 and 293117 are calculated.The experimental alpha-decay energies and half-lives of the two alpha-decay chains are reasonably reproduced by the model The detailed discussions on the binding energies, alpha-decay energies, half-lives, quadrupole deformations, potential energy curves, and single particle levels of the two alpha-decay chains are made.

  9. Alpha Decay in the Complex Energy Shell Model

    CERN Document Server

    Betan, R Id

    2012-01-01

    Alpha emission from a nucleus is a fundamental decay process in which the alpha particle formed inside the nucleus tunnels out through the potential barrier. We describe alpha decay of $^{212}$Po and $^{104}$Te by means of the configuration interaction approach. To compute the preformation factor and penetrability, we use the complex-energy shell model with a separable T=1 interaction. The single-particle space is expanded in a Woods-Saxon basis that consists of bound and unbound resonant states. Special attention is paid to the treatment of the norm kernel appearing in the definition of the formation amplitude that guarantees the normalization of the channel function. Without explicitly considering the alpha-cluster component in the wave function of the parent nucleus, we reproduce the experimental alpha-decay width of $^{212}$Po and predict an upper limit of T_{1/2}=5.5x10^{-7} sec for the half-life of $^{104}$Te. The complex-energy shell model in a large valence configuration space is capable of providing ...

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

    CERN Document Server

    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.

  11. Bremsstrahlung during $\\alpha$-decay: quantum multipolar model

    CERN Document Server

    Maydanyuk, Sergei P

    2008-01-01

    In this paper the improved multipolar model of bremsstrahlung accompanied the $\\alpha$-decay is presented. The angular formalism of calculations of the matrix elements, being enough complicated component of the model, is stated in details. A new definition of the angular (differential) probability of the photon emission in the $\\alpha$-decay is proposed where direction of motion of the $\\alpha$-particle outside (with its tunneling inside barrier) is defined on the basis of angular distribution of its spacial wave function. In such approach, the model gives values of the angular probability of the photons emission in absolute scale, without its normalization on experimental data. Effectiveness of the proposed definition and accuracy of the spectra calculations of the bremsstrahlung spectra are analyzed in their comparison with experimental data for the $^{210}{\\rm Po}$, $^{214}{\\rm Po}$, $^{226}{\\rm Ra}$ and $^{244}{\\rm Cm}$ nuclei, and for some other nuclei predictions are performed (in absolute scale). With ...

  12. Interaction of radiation damage with strain field around. cap alpha. -precipitates in electron-irradiated. beta. -Nb-Zr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, K.; Kinoshita, C.; Kitajima, S.; Muroo, Y. (Kyushu Univ., Fukuoka (Japan). Dept. of Nuclear Engineering)

    1985-05-01

    The strain field around ..cap alpha..-precipitates (hcp) in the ..beta..-Nb-Zr phase has been evaluated to study its relaxation mechanism during electron irradiation in a high voltage electron microscope. The crystallography of the ..cap alpha..-precipitates is determined to be of Burgers' orientation relationship with the ..beta..-phase. The compressive strain field around the ..cap alpha..-precipitates is detected and determined by use of the strain contrast of electron microscopy and the elastic continuum theory. The relaxation process of the strain field around the ..cap alpha..-precipitates is observed during electron irradiation, and is analyzed in terms of accumulation of vacancies.

  13. Pressure phase lines and enthalpies for the. cap alpha. -. beta. and. beta. -liquid transitions in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Abey, A.

    1984-10-31

    The effect of hydrostatic pressure on the ..cap alpha..-..beta.. and ..beta..-liquid transition temperatures in Be was measured in a gas pressure system. Differential thermal analysis was used in the pressure range from 0.1 MPa to 0.7 GPa. For the ..cap alpha..-..beta.. transition, dT/dP = 43 +- 7 K/GPa; for the ..beta..-liquid transition, dT/dP = 35 +- 7 K/GPa. Although it is possible that large systematic errors may arise from experimental procedures, our results are seriously at odds with those of other investigators. Transition enthalpies for the ..cap alpha..-..beta.. and ..beta..-liquid transitions were 1.9 +- 0.2 and 2.2 +- 0.2 kcal/g.m., respectively, at a pressure of 0.1 MPa.

  14. Biological activity of 1. cap alpha. -hydroxyvitamin D/sub 2/ in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, L.E.; Schnoes, H.K.; DeLuca, H.F.

    1978-01-01

    The biological activity of 1..cap alpha..-hydroxyvitamin D/sub 2/ has been determined in vitamin D-deficient rats. In the calcification of the rachitic epiphyseal plate, 1..cap alpha..-hydroxyvitamin D/sub 2/ is more active than 25-hydroxyvitamin D/sub 3/, while it is equally active in stimulating intestinal calcium absorption. On the other hand, it is much less active (one-third to one-fifth) than 25-hydroxyvitamin D/sub 3/ in the mobilization of calcium from bone. In both the intestinal and bone responses, 1..cap alpha..-hydroxyvitamin D/sub 2/ (312 pmol) is active in nephrectomized rats while 15-hydroxyvitamin D/sub 3/ is not.

  15. Transport of. cap alpha. -aminoisobutyric acid into rat parotid after X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bodner, Lipa

    1989-04-01

    Rat parotid gland exposed to 20 Gy X-irradiation exhibits functional alteration 3 days after exposure. The flow rate of saliva and the uptake of ..cap alpha..-aminoisobutyric acid by the gland was reduced to 50% of values for the control non-irradiated glands. When the same gland was studied in an in vitro system it functioned normally. K/sup +/ release and ..cap alpha..-aminoisobutyric acid uptake by the irradiated dispersed acinar cells was comparable to the control. Transport alteration from the circulatory system into the parotid gland may cause the initial radiation-induced damage.

  16. On surface clustering and Pauli principle effects in alpha decay

    International Nuclear Information System (INIS)

    The importance of the correct description of nuclear surface region in alpha decay calculations is pointed out. A model is proposed takinq into account explicitly surface clustering and Pauli principle effects which are essential in this region. A method for solving the main integrodifferential equation of the model by using the oscillator shell basis and the Collatz method is worked out. The first numerical results are obtained for nonlocal potential of the atpha particle-daughter nucleus interaction

  17. Cryogenic Detectors for Rare Alpha Decay Search: A New Approach

    Science.gov (United States)

    Casali, N.; Dubovik, A.; Nagorny, S.; Nisi, S.; Orio, F.; Pattavina, L.; Pirro, S.; Schäffner, K.; Tupitsyna, I.; Yakubovskaya, A.

    2016-08-01

    The detection of ^{148}Sm alpha decay with a precise measured half-life of ( {6.4_{-1.3}^{+1.2} }) × 10^{15}y and a Q-value of 1987.3 ± 0.5 keV was achieved by a new experimental approach, where a conventional ZnWO4 scintillating crystal doped with enriched ^{148}Sm isotope is operated as a cryogenic scintillating bolometer (phonon and light channel) at mK-temperatures.

  18. Effect of heating rate on temperature of titanium alloy (. cap alpha. +. beta. ). -->. beta. transformaton

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, V.N.; Ivasishin, O.M.; Markovskij, P.E. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)

    1985-01-01

    The effect of doping of two-phase titaniums alloys and morphology of initial structure on the Tsub(t) temperature shift value of (..cap alpha..+..beta..)..--> beta.. transformation depending on heating rate is investigated. It has been found that the Tsub(t) shift occurs in the strictly determined temperature range depending on chemical alloy composition. The Tsub(t) shift is directly proportional to the Ksub(..beta..) coefficient applied as a quantitative alloying characteristic as well as a dimensional factor equal either to the plate thickness or the ..cap alpha..-phase globule diameter depending on the type of initial structure. In the limits of this temperature range the (..cap alpha..+..beta..)..--> beta..-transformation occurs completely according to the diffusion mechanism. The critical heating rate at which maximum permissible Tsub(t) value is attained and above which its stabilization is observed is determined by the same parameters - the alloy doping degree characterized by the Ksub(..beta..) coefficient and the ..cap alpha..-phase crystal dimensions in the initial structure.

  19. Anti-cluster Decay and Anti-alpha Decay of Antimatter nuclei

    CERN Document Server

    Poenaru, D N; Greiner, W

    2015-01-01

    A broad extension of periodic system into the sector of antimatter could be possible sometimes in a remote future. We expect that anti-alpha spontaneous emission from an antimatter nucleus will have the same Q-value and half-life as alpha emission from the corresponding mirror nucleus. This is the consequence of the invariance of binding energy as well as of the surface and Coulomb energy when passing from matter to antimatter nuclei with the the same mass number and the same atomic number. The Q-values and half-lives of all measured up to now 27 cluster radioactivities are given together with Q-values and half-lives of the most important competitor --- $\\alpha$ decay. The lightest anti-alpha emitter, $^8\\bar{Be}$, will have a very short half-life of about $81.9\\cdot 10^{-18}$ s.

  20. $\\alpha_s$ analyses from hadronic tau decays with OPAL and ALEPH data

    CERN Document Server

    Boito, Diogo; Maltman, Kim; Peris, Santiago

    2016-01-01

    Recently, we extracted the strong coupling, $\\alpha_s(m_\\tau^2)$, from the revised ALEPH data for non-strange hadronic tau decays. Our analysis is based on a method previously used for the determination of the strong coupling from OPAL data. In our strategy, we employ different moments of the spectral functions both with and without pinching, including Duality Violations, in order to obtain fully self-consistent analyses that do not rely on untested assumptions (such as the smallness of higher dimension contributions in the OPE). Here we discuss the $\\alpha_s$ values obtained from the ALEPH and the OPAL data, the robustness of the analysis, as well as non-perturbative contributions from DVs and the OPE. We show that, although the $\\alpha_s$ determination is sound, non-perturbative effects limit the accuracy with which one can extract the strong coupling from tau decay data. Finally, we discuss the compatibility of the data sets and the possibility of a combined analysis.

  1. Agonist-promoted desensitization and phosphorylation of. cap alpha. /sub 1/-adrenergic receptors coupled to stimulation of phosphatidylinositol metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Leeb-Lundberg, L.M.F.; Cotecchia, S.; Caron, M.G.; Lefkowitz, R.J.

    1986-03-05

    In the DDT/sub 1/ MF-2 hamster vas deferens smooth muscle cell line the ..cap alpha../sub 1/-adrenergic receptor (..cap alpha../sub 1/-AR) agonist norepinephrine (NE) promotes rapid attenuation of ..cap alpha../sub 1/-AR-mediated phosphatidylinositol (PI) metabolism which is paralleled by rapid phosphorylation of the ..cap alpha../sub 1/-AR. Cells were labeled by incubation with /sup 32/P/sub i/. Coincubation with NE (100 ..mu..M) significantly increases the rate of /sup 32/P-labeling of both PI and phosphatidic acid. Pretreatment of cells with 100 ..mu..M NE (in the presence of 1 ..mu..M propranolol to prevent ..beta..-AR interactions) results in a drastic attenuation of the NE response on PI metabolism. ..cap alpha../sub 1/-AR from labeled cells can be solubilized and purified by affinity chromatography on Affigel-A55414 and wheat germ agglutinin agarose chromatography. SDS-PAGE of purified ..cap alpha../sub 1/-AR shows a NE-promoted increase in phosphorylation of the M/sub r/ 80K ligand binding peptide. Stoichiometry of phosphorylation increases from approx. 1 mol phosphate/mol ..cap alpha../sub 1/-AR in the basal condition to approx. 2.5 after NE treatment. Both desensitization and phosphorylation are rapid being maximal within 10-20 min of agonist exposure. These results together with previous findings that phorbol esters promote rapid ..cap alpha../sub 1/-AR uncoupling and phosphorylation suggest that receptor phosphorylation is an important mechanism of regulation of ..cap alpha../sub 1/-AR receptor responsiveness.

  2. Radiation electromagnetic effect in germanium crystals under high-energy. cap alpha. -particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, I.K.; Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-05-01

    Results of experimental investigation into radiation electromagnetic effect (REM) in samples of germanium crystals under approximately 40 MeV ..cap alpha..-particle irradiation in a cyclotron are presented. A high level of excitation, volumetric character of generation of non-equilibrium carriers and formation of defects as well as the form of their spatial distribution are shown to result in some peculiarities of the EMF of the REM effect on the particle flux, fluence and sample parameters. Agreement of theoretical calculations, conducted with account of specificity of ..cap alpha..-particle interaction with a crystal, and experimental data is obtained. It is revealed that the REM effect can be applied in obtaining data on spatial distribution of non-equilibrium carrier concentrations along the particle trajectory in the crystal.

  3. Radiation-electromagnetic effect in germanium crystals irradiated with high-energy. cap alpha. particles

    Energy Technology Data Exchange (ETDEWEB)

    Kikoin, I.K.; Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-05-01

    An experimental investigation was made of the radiation-electromagnetic effect in germanium crystals irradiated in a cyclotron with ..cap alpha.. particles of energies up to 40 MeV. The high excitation rate, the bulk nature of generation of nonequilibrium carriers and defects, and their spatial distributions gave rise to several special features in the dependence of the emf due to the radiation-electromagnetic effect on the particle flux, fluence, and parameters of samples. Theoretical calculations carried out allowing for the specific nature of the interaction of ..cap alpha.. particles with crystals agreed well with the experimental results. The radiation-electromagnetic effect could be used to obtain information on the nature of the spatial distribution of the density of nonequilibrium carriers along the trajectory of a particle in a crystal.

  4. Effect of temperature on interatomic distances in pyroelectric. cap alpha. -LiIO/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Coquet, E.; Crettez, J.M. (Laboratoire d' Optique du Reseau Cristallin, Faculte des Sciences, Dijon, France); Pannetier, J.; Bouillot, J. (Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)); Damien, J.C. (Lille-1 Univ., 59 - Villeneuve-d' Ascq (France))

    1983-08-01

    The crystal structure of ..cap alpha..-LiIO/sub 3/ (space group P6/sub 3/) has been refined from neutron and X-ray diffraction data at different temperatures between room temperature and 525 K. The Li atom is well located even at temperatures close to the ..cap alpha.. ..-->.. ..gamma.. phase transition and its thermal parameters do not exhibit any anomalous behaviour. The thermal expansion is analysed in terms of IO/sub 3/-group rotations and expansion of LiO/sub 6/ octahedra; the role of the iodine lone pair in the packing of iodate structures is discussed. The spontaneous polarization is calculated on the basis of a simple point-charge model and the calculated pyroelectric coefficient P/sub 3/ is found to be in fair agreement with the experimental value.

  5. Factorization of the fragmentation cross sections in relativistic pA and. cap alpha. A interactions

    Energy Technology Data Exchange (ETDEWEB)

    Abashidze, L.I.; Avdeichikov, V.V.; Beznogikh, G.G.; Bogatin, V.I.; Budilov, V.A.; Gorshkov, N.L.; Zlomanchuk, Y.; Zhidkov, N.K.; Lozhkin, O.V.; Mruvchinski, S.

    1985-08-01

    We have experimentally demonstrated the factorization of the cross sections for production of the isotopes /sup 3//sup ,//sup 4/He with kinetic energy T> or approx. =100 MeV emitted at an angle 90/sup 0/ in the lab from the nuclei C, Cu, and Au in bombardment by ..cap alpha.. particles with energy 3.33 GeV/nucleon and by protons with energy 6.6 GeV.

  6. Fine structure in the alpha decay of {sup 224} U

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Martens, A.; Hauschild, K.; Rezynkina, K. [CNRS-IN2P3, CSNSM, Universite Paris Sud, Orsay (France); Dorvaux, O.; Gall, B.; Dechery, F.; Faure, H. [CNRS-IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); Yeremin, A.V.; Chelnokov, M.L.; Chepigin, V.I.; Isaev, A.V.; Izosimov, I.N.; Katrasev, D.E.; Kuznetsov, A.N.; Kuznetsova, A.A.; Malyshev, O.N.; Popeko, A.G.; Sokol, E.A.; Svirikhin, A.I. [JINR, FLNR, Dubna (Russian Federation); Piot, J. [CNRS-IN2P3, GANIL, CEA-DSM, Caen (France); Rubert, J. [CNRS-IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); CNRS-IN2P3, LPSC, Universite Grenoble-Alpes, Grenoble (France)

    2014-08-15

    {sup 224}U nuclei were populated in fusion-evaporation reactions using a {sup 206}Pb target and an intense {sup 22}Ne beam. Fusion-evaporation residues were separated by the new separator SHELS at the FLNR, Dubna and implanted into a large-area double-sided silicon strip detector. Position- and time-correlated alpha decays were used to identify evaporation residues. A new α -decay line at 8095(11) keV was observed in this work and assigned as the decay from {sup 224}U to the first excited 2{sup +} in the daughter nucleus {sup 220}Th. Coincident photons were also observed allowing to unambiguously determine the excitation energy of the first excited 2{sup +} state in {sup 220}Th to be 386.5(1) keV and not 373.3(1)keV as previously reported. The half-life of {sup 224}U was measured to be 396(17)μs. (orig.)

  7. A fractional calculus approach to investigate the alpha decay processes

    International Nuclear Information System (INIS)

    In this study, the nuclear decay equation is taken under consideration by making use of fractional calculus. In this context, the first-order time derivative is changed to a Caputo fractional derivative hence, the resulting equation is the time fractional nuclear decay equation. The solution of this equation is obtained in terms of Mittag–Leffler function which plays an important role to study the non-Markovian feature of physical processes. As an application of this time fractional formalism, alpha decay half-life values have been calculated for Pb, Po, Rn, Ra, Th and U isotopes. Consequently, the theoretical half-life values have been obtained in consistent with the experimental data. The dependence of the order of fractional derivative μ being a measure of fractality of time, on the nuclear structure has been established. In the investigations carried out, we have arrived to the conclusion that for the μ values which are closed to one, where time becomes homogenous and continuous, the shell closure effects are predominant and that the fractional derivative order μ (i.e., fractality of time) and nuclear structure are closely related to each other. (author)

  8. Accumulation of glycation products in. cap alpha. -H pig lens crystallin and its bearing to diabetic cataract genesis

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, P.; Cabezas-Cerrato, J.

    1988-01-01

    The incorporation of /sup 11/C-glucose in native pig crystalline by in vitro incubation was found, after subsequent dialysis, to affect all 5 classes of crystallin separated by Sepharose CL-6B column chromatography. Though the radioactivity of the ..cap alpha..-H fraction was three times greater than that of any of the others, autoradiographs of SDS-PAGE gels showed /sup 11/C-glucose adducts to be present in all soluble protein subunits, without there being any evidence of preferential glycation of the ..cap alpha..-H subunits. The concentration of stable glycation products in the ..cap alpha..-H chromatographic fraction of soluble crystallins is suggested to be due the addition of glycated material to this fraction as result of glycation-induced hyperaggregation, and not because the ..cap alpha..-H subunits were especially susceptible to glycation.

  9. Determination of the M-matrix in d-. cap alpha. elastic scattering from a complete set of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, K.; Grueebler, W.; Sperisen, F.; Ghazi-Wakili, K.; Koenig, V.; Schmelzbach, P.A.; Vuaridel, B.; Bittcher, M.; Singy, D.; Ulbricht, J.

    1988-05-02

    Six polarization transfer coefficients of the d-..cap alpha.. elastic scattering have been measured at an incident deuteron energy of 11.9 MeV and a scattering angle theta/sub lab/ = 37.3/sup 0/. Together with earlier data on cross section and analyzing powers, a complete set of measurements allows to deduce the d-..cap alpha.. M-matrix directly from experiment.

  10. Control of. cap alpha. -amylase mRNA accumulation by gibberellic acid and calcium in barley aleurone layers

    Energy Technology Data Exchange (ETDEWEB)

    Deikman, J.; Jones, R.L.

    1985-01-01

    Pulse-labeling of barley (Hordeum vulgare L. cv Himalaya) aleurone layers incubated for 13 hours in 2.5 micromolar gibberellic acid (GA/sub 3/) with or without 5 millimolar CaCl/sub 2/ shows that ..cap alpha..-amylase isozymes 3 and 4 are not synthesized in vivo in the absence of Ca/sup 2 +/. No difference was observed in ..cap alpha..-amylase mRNA levels between layers incubated for 12 hours in 2.5 micromolar GA/sub 3/ with 5 millimolar CaCl/sub 2/ and layers incubated in GA/sub 3/ alone. RNA isolated from layers incubated for 12 hours in GA/sub 3/ with and without CA/sup 2 +/. A cDNA clone for ..cap alpha..-amylase was isolated and used to measure ..cap alpha..-amylase mRNA levels in aleurone layers incubated in the presence and absence of Ca/sup 2 +/ was translated in vitro and was found to produce the same complement of translation products regardless of the presence of Ca/sup 2 +/ in the incubation medium. Immunoprecipitation of translation products showed that the RNA for ..cap alpha..-amylase synthesized in Ca/sup 2 +/-deprived aleurone layers was translatable. Ca/sup 2 +/ is required for the synthesis of ..cap alpha..-amylase isozymes 3 and 4 at a step after mRNA accumulation and processing.

  11. Capillary electrophoretic study of thiolated alpha-cyclodextrin-capped gold nanoparticles with tetraalkylammonium ions.

    Science.gov (United States)

    Paau, Man Chin; Lo, Chung Keung; Yang, Xiupei; Choi, Martin M F

    2009-11-27

    Capillary zone electrophoresis (CZE) has been employed to characterize nanometer-sized thiolated alpha-cyclodextrin-capped gold nanoparticles (alpha-CD-S-AuNPs). The addition of tetrabutylammonium (Bu(4)N(+)) ions to the run buffer greatly narrows the migration peak of alpha-CD-S-AuNP. The optimal run buffer was determined to be 10mM Bu(4)N(+) in 30 mM phosphate buffer at pH 12 and an applied voltage of 15 kV. The effect of various tetraalkylammonium ions on the peak width and electrophoretic mobility (mu(e)) of alpha-CD-S-AuNP was studied in detail. Bu(4)N(+) ions assist in inter-linking the alpha-CD-S-AuNPs and narrowing the migration peak in CZE. This observation can be explained by the fact that each Bu(4)N(+) ion can simultaneously interact with several hydrophobic cavities of the surface-attached alpha-CDs on AuNPs. The TEM images show that alpha-CD-S-AuNPs with Bu(4)N(+) are linked together but in the absence of Bu(4)N(+), they are more dispersed. The migration mechanism in CZE is based on the formation of inclusion complexes between Bu(4)N(+) and alpha-CD-S-AuNPs which induces changes in the charge-to-size ratio of alpha-CD-S-AuNPs and mu(e). An inverse linear relationship (r(2)>0.998) exists between the mu(e) and size of alpha-CD-S-AuNPs in the core range 1.4-4.1 nm. The CZE analyses are rapid with migration time less than 4 min. A few nanoliters of each of the alpha-CD-S-AuNP samples were injected hydrodynamically at 0.5 psi for 5s. Our work confirms that CZE is an efficient tool for characterizing the sizes of alpha-CD-S-AuNPs using Bu(4)N(+) ions. PMID:19853853

  12. Involvement of prostaglandins F/sub 2. cap alpha. / and E/sub 1/ with rabbit endometrium

    Energy Technology Data Exchange (ETDEWEB)

    Orlicky, D.J.

    1985-01-01

    Several growth factors and hormones are thought to play a role in the growth control of endometrial cells. The authors have shown that prostaglandin F/sub 2..-->../ (PGF/sub 2..cap alpha../) is a growth factor for primary cultures of rabbit endometrium cultured in chemically-defined serum-free medium and that prostaglandin E/sub 1/ (PGE/sub 1/) antagonizes the PGF/sub 2..-->../ induction of growth. Both (/sup 3/H)PGF/sub 2..cap alpha../ and (/sup 3/H)PGE/sub 1/ bind in a time and temperature dependent, dissociable, saturable and specific manner. The binding of (/sup 3/H)PGF/sub 2..cap alpha../ and (/sup 3/H)PGE/sub 1/ can be both down and up regulated and is enzyme sensitive. PGE /sub 1/ stimulates intracellular cAMP synthesis and accumulation in a time and concentration dependent manner. PGF/sub 2..cap alpha../ probably exerts its effects through an amiloride-sensitive intermediate. Both PGF/sub 2..cap alpha../ and PGE/sub 1/ are constitutively synthesized by these primary cultures, and they have shown this synthesis to be both drug and hormone sensitive. They hypothesize that it is the ratio, rather than the absolute quantities, of PGF/sub 2..cap alpha../ and PGE/sub 1/ which is of more importance in the regulation of endometrial cell growth. Furthermore, they believe this regulation of endometrial growth plays a role in control of proliferation during the decidual response and that a derangement in the ratio of these prostaglandins may lead to either infertility or hyperplasia. The ability of these cultures to synthesize prostaglandins in a hormonally regulatable manner may be of importance in the study of dysmenorrhea and uterine cramping as caused by the myometrial contracting prostaglandin, PGF/sub 2..cap alpha../.

  13. Secondary. cap alpha. -deuterium kinetic isotope effects in solvolyses of ferrocenylmethyl acetate and benzoate in ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Sutic, D. (Univ. of Zagreb, Yugoslavia); Asperger, S.; Borcic, S.

    1982-12-17

    Secondary ..cap alpha..-deuterium kinetic isotope effects (KIE) in solvolyses of ferrocenyldideuteriomethyl acetate and benzoate were determined in 96% (v/v) ethanol, at 25/sup 0/C, as k/sub H//k/sub D/ = 1.24 and 1.26, respectively. The KIEs were also determined in the presence of 0.1 mol dm/sup -3/ lithium perchlorate: the k/sub H//k/ sub D/ values were 1.23 and 1.22 for acetate and benzoate complexes, respectively. The maximum KIE for the C-O bond cleavage of a primary substrate is as large as, or larger than, that of secondary derivatives, which is estimated to be 1.23 per deuterium. The measured KIE of about 12% per D therefore represents a strongly reduced effect relative to its maximum. The solvolyses exhibit ''a special salt effect''. This effect indicates the presence of solvent-separated ion pairs and the return to tight pairs. As the maximum KIE is expected in solvolyses involving transformation of one type of ion pair into another, the strongly reduced ..cap alpha..-D KIE supports the structure involving direct participation of electrons that in the ground state are localized at the iron atom. The alkyl-oxygen cleavage is accompanied by 10-15% acyl-oxygen cleavage.

  14. No effect of 5-fluorouracil on the properties of purified. cap alpha. -amylase from barley half-seeds

    Energy Technology Data Exchange (ETDEWEB)

    Rodaway, S.J.; Kende, H.

    1978-01-01

    Amylase has been purified from de-embryonated seeds of barley (Horedeum vulgare L. cv. Betzes) which have been incubated on 10/sup 6/M gibberellic acid (GA/sub 3/) following 3 days of imbibition in buffer. Incubation of the half-seeds in up to 10/sup -2/ M 5-fluorouracil (5-FU) during the entire incubation period, including imbibition, had no effect on any of the following characteristics of purified ..cap alpha..-amylase: thermal stability in the absence of calcium, molecular weight of the enzyme, isozyme composition, specific activity, or the amount of ..cap alpha..-amylase synthesized by the aleurone tissue. The synthesis of rRNA and tRNA was strongly inhibited by 5-FU, indicating that the analog had entered the aleurone cells. These results are not in agreement with those of Carlson (Nature New Biology 237: 39-41 (1972)) who found that treatment of barley aleurone with 10/sup -4/ M 5-FU to the addition of GA/sub 3/ resulted in decreased thermal stability of GA/sub 3/-induced ..cap alpha..-amylase and who interpreted this as evidence that the mRNA for ..cap alpha..-amylase was synthesized during the imbibition of the aleurone tissue and independently of gibberellin action. Results of the present experiments indicate that the thermal stability of highly purified ..cap alpha..-amylase is not altered by treatment of barley half-seeds with 5-FU, and that 5-FU cannot be used as a probe to examine the timing of ..cap alpha..-amylase mRNA synthesis.

  15. Alpha decay energies and half-lives for possibly synthesized superheavy elements

    Institute of Scientific and Technical Information of China (English)

    ZHI Qi-Jun; REN Zhong-Zhou; ZHANG Xiao-Ping; ZHOU Xiao-Hong; GAN Zai-Guo; QIN Zhi; XU Hu-Shan

    2008-01-01

    We investigate the ground state properties of some superheavy nuclei, which may be synthesized in future experiments. Special emphases are placed on the alpha decay energies and half-lives. The alpha decay energies and half-lives from different theoretical models are compared and discussed comprehensively. Through these calculations and comparisons, the optimal superheavy elements to be synthesized in future experiments are proposed theoretically.

  16. Alpha decay as a probe for the structure of neutron-deficient nuclei

    CERN Document Server

    Qi, Chong

    2016-01-01

    The advent of radioactive ion beam facilities and new detector technologies have opened up new possibilities to investigate the radioactive decays of highly unstable nuclei, in particular the proton emission, $\\alpha$ decay and heavy cluster decays from neutron-deficient (or proton-rich) nuclei around the proton drip line. It turns out that these decay measurements can serve as a unique probe for studying the structure of the nuclei involved. On the theoretical side, the development in nuclear many-body theories and supercomputing facilities have also made it possible to simulate the nuclear clusterization and decays from a microscopic and consistent perspective. In this article we would like to review the current status of these structure and decay studies in heavy nuclei, regarding both experimental and theoretical opportunities. We then discuss in detail the recent progress in our understanding of the nuclear $\\alpha$ formation probabilities in heavy nuclei and their indication on the underlying nuclear st...

  17. Study of rare alpha decays with scintillating bolometers

    Energy Technology Data Exchange (ETDEWEB)

    Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza University of Roma, Roma I-00185 (Italy); INFN, Sezione di Roma, Roma I-00185 (Italy)

    2013-08-01

    Rare α decays can be studied with an unprecedented sensitivity by means of scintillating bolometers, as these detectors can provide a large source mass as well as an excellent resolution and can disentangle the nature of the interacting particle thanks to the different light yield. As an example of the results that can be obtained with this technique, I report the conclusive test on the identification of {sup 209}Bi decay and the measurement of the half-life of this isotope. In addition, I present a measurement with a PbWO{sub 4} scintillating bolometer, in which the lead isotopes decays were studied.

  18. Alpha decay properties of heavy and superheavy elements

    Indian Academy of Sciences (India)

    G M Carmel Vigila Bai; J Umai Parvathiy

    2015-01-01

    Analysing accurately the lifetimes of -decay chains is an important tool to detect and study the properties of superheavy nuclei. 48Ca is used in the synthesis of superheavy nuclei = 106−118 at Dubna. The experimental work of 48Ca projectiles at Dubna has given an opportunity to study the superheavy element (SHE). Here, the -decay properties for = 106–118 are evaluated using our CYE model and are compared with the available experimental and theoretical values.

  19. Recent $\\alpha$ decay half-lives and analytic expression predictions including superheavy nuclei

    CERN Document Server

    Royer, G

    2008-01-01

    New recent experimental $\\alpha$ decay half-lives have been compared with the results obtained from previously proposed formulas depending only on the mass and charge numbers of the $\\alpha$ emitter and the Q$\\alpha$ value. For the heaviest nuclei they are also compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The correct agreement allows us to make predictions for the $\\alpha$ decay half-lives of other still unknown superheavy nuclei from these analytic formulas using the extrapolated Q$\\alpha$ of G. Audi, A. H. Wapstra, and C. Thibault [Nucl. Phys. A729, 337 (2003)].

  20. Study of the Alpha-Decay Chain for7753 194Rn with Relativistic Mean-Field Theory

    Institute of Scientific and Technical Information of China (English)

    SHENG Zong-Qiang; GUO Jian-You

    2008-01-01

    The structures of the nuclei on the alpha-decay chain of 194Rn are investigated in the deformed relativistic mean-field theory with the effective interaction TMA. We put an emphasis on the ground state properties of 194Rn. The calculated alpha-decay energies and lifetimes are both very close to the experimental data for 186pb and 190po. For 194 Rn, the deviations are a little large on both the alpha-decay energy and the lifetime. We also calculate the alpha-decay energies for the isotopes 192~208Rn. The tendency for the change of the alpha-decay energies with neutron number is correctly reproduced in the relativistic mean-field theory (RMF). In general, the RMF theory can give a good description of the alpha decay chain of 194Rn.

  1. Alpha-decay-induced fracturing in zircon: the transition from the crystalline to the metamict state

    International Nuclear Information System (INIS)

    A natural single crystal of zircon, ZrSiO4, from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 1016 and 0.8 x 1016 alpha-event per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 1016 alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides

  2. Alpha-decay--induced fracturing in zircon: the transition from the crystalline to the metamict state.

    Science.gov (United States)

    Chakoumakos, B C; Murakami, T; Lumpkin, G R; Ewing, R C

    1987-06-19

    A natural single crystal of zircon, ZrSiO(4,) from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10(16) and 0.8 x 10(16) alpha-events per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 10(16) alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides. PMID:17835739

  3. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Gal. cap alpha. 1-3Gal. beta. 1-4GlcNaC sequences

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.F.; Krivan, H.; Wilkins, T.; Smith, D.F.

    1987-05-01

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Gal..cap alpha..1-3Gal..beta..1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with ..cap alpha..-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified /sup 125/I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Gal..cap alpha..1-3Gal..beta..1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with ..cap alpha..-galactosidase abolished binding. Forsmann glycolipid, globoside, Gal..cap alpha..1-4 Gal..beta..1-4Glc-cer, and Gal..cap alpha..1-3Gal..beta..1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Gal..cap alpha..1-3Gal..beta..1-4GlcNAc.

  4. Role of nuclear surface tension coefficient in alpha decay process of the superheavy nuclei

    International Nuclear Information System (INIS)

    The present paper role of nuclear surface tension in alpha decay resulted from the need to improve the Isospin Cluster Model, where the excess of neutron and proton numbers are taken in account effectively of a nucleus in decay calculations. The appropriate value of nuclear surface tension coefficient in proximity potential which plays an important role to estimate the nuclear attraction between two nuclear surfaces is reviewed, in this model. The nuclear proximity force is proportional to the surface tension and its contribution necessarily should be appropriate. The synthesis of super heavy elements, formed by either of cold fusion or hot fusion process, is primarily decay through alpha-particle emission. The successive emission of alpha particles from a superheavy element ends at spontaneous fission

  5. H/sub. cap alpha. / monitors for the Advanced Limiter Test-II (ALT-II) on TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, T.

    1988-05-01

    The H/sub ..cap alpha../ monitor system installed on TEXTOR in conjunction with the Advanced Limiter Test-II (ALT-II) toroidal belt pump limiter is introduced. The monitors are used to study edge particle fluxes and recycling, correlations to confinement properties of core and edge plasma with ALT-II, and also high-power auxiliary heating (/approximately/5 MW) during long-pulse (/approximately/4-s) operation of TEXTOR. A model of the edge particle flux based on the H/sub ..cap alpha../ measurements is presented. The ALT-II experiments are to be carried out in various phases. Here we discuss the results obtained from the monitor system during the initial phase of operations following the installation of the ALT-II limiter, with ohmic heating only. 15 refs., 21 figs.

  6. On the Validity of the Geiger-Nuttall Alpha-Decay Law and its Microscopic Basis

    CERN Document Server

    Qi, C; Huyse, M; Liotta, R J; Van Duppen, P; Wyss, R

    2014-01-01

    The Geiger-Nuttall (GN) law relates the partial $\\alpha$-decay half-life with the energy of the escaping $\\alpha$ particle and contains for every isotopic chain two experimentally determined coefficients. The expression is supported by several phenomenological approaches, however its coefficients lack a fully microscopic basis. In this paper we will show that: 1) the empirical coefficients that appear in the GN law have a deep physical meaning and 2) the GN law is successful within the restricted experimental data sets available so far, but is not valid in general. We will show that, when the dependence of logarithm values of the $\\alpha$ formation probability on the neutron number is not linear or constant, the GN law is broken. For the $\\alpha$ decay of neutron-deficient nucleus $^{186}$Po, the difference between the experimental half-life and that predicted by the GN Law is as large as one order of magnitude.

  7. Alpha-decay-induced fracturing in zircon - The transition from the crystalline to the metamict state

    Science.gov (United States)

    Chakoumakos, Bryan C.; Murakami, Takashi; Lumpkin, Gregory R.; Ewing, Rodney C.

    1987-06-01

    Zonation due to alpha-decay damage in a natural single crystal of zircon from Sri Lanka is discussed. The zones vary in thickness on a scale from one to hundreds of microns. The uranium and thorium concentrations vary from zone to zone such that the alpha decay dose is between 0.2 x 10 to the 16th and 0.8 x 10 to the 16th alpha-events per milligram. The transition from the crystalline to the aperiodic metamict state occurs over this dose range. At doses greater than 0.8 x 10 to the 16th alpha events/mg there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.

  8. Study of the excited levels of 233Pa by the 237Np alpha decay

    International Nuclear Information System (INIS)

    The excited levels in 233Pa following the 237Np alpha decay have been studied, by performing different experiences to complete available data and supply new information. Thus, two direct alpha spectrum measurement, one alpha-gamma bidimensional coincidence experiment, three gamma-gamma and gamma-X ray coincidences and some other measurements of the gamma spectrum, direct and coincident with alpha-particles have been made. These last experiences have allowed to obviate usual radiochemical separation methods, the 233Pa radioactive descendent interferences being eliminated by means of the coincidence technic. As a result, a primary decay scheme has been elaborated, including 15 new gamma transitions and two new levels, not observed in the most recent works. (Author) 60 refs

  9. Determination of arsenic, antimony, and bismuth in silicon using 200 keV. cap alpha. -particle backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Hnatowicz, V.; Kvitek, J. (Ceskoslovenska Akademie Ved, Rez. Ustav Jaderne Fyziky); Krejci, P.; Rybka, V. (Tesla, Prague (Czechoslovakia)); Pelikan, L. (Technical University of Prague (Czechoslovakia). Dept. of Microelectronics)

    1982-11-16

    Concentration profiles of As, Sb, and Bi implanted into Si are studied using backscattering of the 200 keV ..cap alpha..-particles. A conventional ion implanter serves as a source of analyzing beam and the scattered particles are detected using a silicon surface barrier detector. Measured projected ranges R/sub P/ of implanted atoms are found to be in satisfactory agreement with theoretical predictions.

  10. Angular correlations and decay branching ratio for excited state of 7Li*(7,45 MeV) in reactions 7Li(alpha, alpha)7Li*

    International Nuclear Information System (INIS)

    Measurements of differential cross-sections of alpha-particle inelastic scattering by 7Li nuclei and 7Li(alpha, alpha 6Li)n, 7Li(alpha, alpha alpha)t reactions have been performed at the energy Ea = 27,2 MeV. Probability of 7Li*(7,45 MeV) decay into 6Li + n channel has been determined from the ratio of cross-sections measured in kinematically complete and incomplete experiments. The large discrepancy of this value (P 0,49 ± 0,06) and of those obtained at the study of 7Li*(7,45 MeV) decay in binary reactions can be explained by the influence of Coulomb field of accompanied alpha-particle on the decay of near-threshold resonances in three-particle reactions

  11. Half-lives with Yukawa proximity potential for alpha-decay process

    International Nuclear Information System (INIS)

    We intend to study the alpha-decay half-lives of some nuclei from ground state to ground state. We consider a potential model with Yukawa proximity potential. We see that the results are in good agreement with the experimental data. (author)

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

    CERN Document Server

    Maydanyuk, Sergei P; Zou, Li-Ping

    2015-01-01

    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 ...

  13. The Resonance Theory of Proton and Alpha Decay from Hot Sources

    CERN Document Server

    Karpeshin, F F; Vardaci, E; Brondi, A; Moro, R; Abramovich, S N; Serov, V I; Vardaci, Emanuele; Brondi, Augusto; Moro, Renata

    2005-01-01

    The consecutive microscopic solution is presented of the problem of tunneling of a particle through a potential barrier. The method is applied to the alpha and proton decay of compound systems formed in fusion reaction. Appearance of the peaks in the spectrum of emitted particles is predicted. The peaks correspond to quasistationary states inside the potential barrier.

  14. Investigation of a gas-catcher/ion guide system using alpha-decay recoil products

    Energy Technology Data Exchange (ETDEWEB)

    Peraejaervi, K. E-mail: kari.perajarvi@phys.jyu.fi; Huikari, J.; Rinta-Antila, S.; Dendooven, P

    2002-04-22

    {sup 219}Rn recoils from the alpha decay of {sup 223}Ra have been used to study the efficiency and delay time distributions of a gas-catcher/ion guide system. Ions with charge states up to +4 were coming out of the gas cell. Combining efficiency and delay time measurements, ion survival times in plasma free conditions can be deduced.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Alpha Decay Potential Barriers and Half-Lives and Analytical Formula Predictions for Superheavy Nuclei

    Science.gov (United States)

    Royer, Guy; Zhang, Hongfei

    The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault.

  17. Revisiting alpha decay-based near-light-speed particle propulsion.

    Science.gov (United States)

    Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu

    2016-08-01

    Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days.

  18. Alpha decay potential barriers and half-lives and analytical formula predictions for superheavy nuclei

    International Nuclear Information System (INIS)

    The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault. (author)

  19. Bremsstrahlung emission probability in the {alpha} decay of {sup 210}Po

    Energy Technology Data Exchange (ETDEWEB)

    Boie, Hans-Hermann

    2009-06-03

    A high-statistics measurement of bremsstrahlung emitted in the {alpha} decay of {sup 210}Po has been performed. The measured differential emission probabilities, which could be followed up to {gamma}-energies of {proportional_to} 500 keV, allow for the first time for a serious test of various model calculations of the bremsstrahlung accompanied {alpha} decay. It is shown that corrections to the {alpha}-{gamma} angular correlation due to the interference between the electric dipole and quadrupole amplitudes and due to the relativistic character of the process have to be taken into account. With the experimentally derived angular correlation the measured energydifferential bremsstrahlung emission probabilities show excellent agreement with the fully quantum mechanical calculation. (orig.)

  20. Angular correlation measurements for 4-{alpha} decaying states in {sup 16}O

    Energy Technology Data Exchange (ETDEWEB)

    Wuosmaa, A.H.; Back, B.B.; Betts, R.R. [and others

    1995-08-01

    Previous measurements of the {sup 12}C({sup 12}C,{sup 8}Be){sup 16}O{sup *}(4 {alpha}) reaction identified discrete levels in {sup 16}O which decay by breakup into 4 {alpha} particles through a number of different decay sequences, including {sup 16}O{sup *} {yields} {sup 8}Be + {sup 8}Be and {alpha} + {sup 12}C (O{sub 2}{sup +}). These states are observed in a range of excitation energies where resonances are observed in inelastic {alpha} + {sup 12}C scattering leading to the {sup 8}Be + {sup 8}Be and {alpha} + {sup 12}C final states. These resonances were associated with 4 {alpha}-particle chain configurations in {sup 16}O. Should the states populated in the {sup 12}C + {sup 12}C reaction possess this same extended structure, it would serve as an important piece of evidence supporting the idea that even more deformed structures are formed in the {sup 24}Mg compound system. In order to more firmly make this association, it is important to determine the spins of the states populated in the {sup 12}C + {sup 12}C reaction.

  1. Phenomenological formula for alpha-decay half-lives

    International Nuclear Information System (INIS)

    A phenomenological formula is presented for the partial half-life from the Q value for α decay. It is constructed in a conventional way by considering the penetrability of a charged particle in a spherical Coulomb potential. Parameters in the formula are fixed because they are determined by physical constants except for the following three adjustable parameters: the product of the collision frequency of an α particle and the formation probability, N; the distance between the charge radius and the radius of an inner point of the Coulomb barrier, r 0; and the odd-mass hindrance, h 0. The values obtained for the three adjustable parameters are reasonable, in contrast with those of conventional models such as the Viola-Seaborg formula. The root-mean-square deviations from experimental partial half-lives for even-even, odd-A, and odd-odd nuclei are 0.344, 0.740, and 0.940 (in log10), respectively. The obtained formula gives half-lives that are two or three times longer than those obtained using the Viola-Seaborg formula in the superheavy nuclear mass region. (author)

  2. Effects of alpha-decay on spent fuel corrosion behaviour

    International Nuclear Information System (INIS)

    An overview of results in the area of spent fuel characterization as nuclear waste is presented. These studies are focused on primary aspects of spent fuel corrosion, by considering different fuel compositions and burn ups, as well as a wide set of environmental conditions. The key parameter is the storage time of the fuel e.g. in view of spent fuel retrieval or in view of its final disposal. To extrapolate data obtainable from a laboratory-acceptable timescale to those expected after storage periods of interest have elapsed (amounting in the extreme case to geological ages) is a tough challenge. Emphasis is put on key aspects of fuel corrosion related to fuel properties at a given age and environmental conditions expected in the repository: e.g. the fuel activity (radiolysis effects), the effects of helium build-up and of groundwater composition. A wide range of techniques, from traditional leaching experiments to advanced electrochemistry, and of materials, including spent fuel with different compositions/burnups and analogues like the so-called alpha-doped UO2, are employed for these studies. The results confirm the safety of European underground repository concepts. (authors)

  3. Evidence for B0->rho0rho0 Decay and Implications for the CKM Angle alpha

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Ben-Haim, E; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Bettarini, S; Bettoni, D; Bevan, A J; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Boyd, J T; Bozzi, C; Brandt, T; Brau, J E; Briand, H; Brown, D N; Bruinsma, M; Brunet, S; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Castelli, G; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Dasu, S; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Escalier, M; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, W T; Forster, I J; Forti, F; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, W; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, F; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martin, E C; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Morris, J P; Muheim, F; Müller, D R; Nagel, M; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Osipenkov, I; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro-Vazquez, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Pelliccioni, M; Perazzo, A; Perl, M; Peruzzi, I M

    2006-01-01

    We search for the decays B0->rho0rho0, B0->rho0f0, and B0->f0f0 in a sample of about 384 million Upsilon(4S)->BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find evidence for B0->rho0rho0 with 3.5 sigma significance and measure the branching fraction BR = (1.07+-0.33+-0.19)10^-6 and longitudinal polarization fraction f_L = 0.87+-0.13+-0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the CKM unitarity angle alpha due to penguin contributions in B-> rho rho decays is 18 degrees at the 1 sigma level. We also set upper limits on the B0->rho0f0 and B0->f0f0 decay rates.

  4. Measurement of $\\alpha_{s}$ and the non-strange spectral functions in hadronic $\\tau$ decays with OPAL

    CERN Document Server

    Menke, S

    1999-01-01

    The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant alpha /sub s/, the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives alpha /sub s/(m/sub tau //sup 2/)=0.348+or-0.009/sub exp/+or-0.019/sub theo/ at the tau - mass scale and alpha /sub s/(m/sub Z//sup 2/)=0.1219+or-0.0010/sub exp/+or-0.0017/sub theo/ at the Z/sup 0/-mass scale. The values obtained for alpha /sub s/(m/sub Z//sup 2/) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3and 4.1 smaller, respectively. The `running' of the strong coupling between s /sub 0/ approximately=1.3 GeV/sup 2/ and s/sub 0/=m/sub tau //sup 2/ has been tested from direct f...

  5. Continuous three-dimensional radiation dosimetry in tissue-equivalent phantoms using electron paramagnetic resonance in L-. cap alpha. -alanine

    Energy Technology Data Exchange (ETDEWEB)

    Wielopolski, L.; Maryanski, M.; Ciesielski, B.; Forman, A.; Reinstein, L.E.; Meek, A.G.

    1987-07-01

    A new tissue-equivalent phantom material has been developed which also acts as a dosimeter. The new phantom material has a similar elemental composition to that of soft tissue and has a density 1.1 g/cm/sup 3/. The phantom has an agar-gel base, and contains crystallized L-..cap alpha..-alanine which traps radiation-induced free radicals. Samples from the phantom were analyzed by an electron paramagnetic resonance (EPR) spectrometer and the intensity of the EPR signal was related to the absorbed dose. When calibrated, the phantom material acts as a dosimeter, with applications in radiation therapy.

  6. O(N{sub f}{alpha}{sup 2}) corrections to muon decay

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, R.G. [Randall Laboratory pf Physics, Ann Arbor, Michigan (United States)

    1997-03-01

    The calculation of the O(N{sub f}{alpha}{sup 2}) corrections to muon decay is described. These are the 2-loop diagrams containing a massless fermion loop and they form an important gauge-invariant subclass. It is shown that all such diagrams can be expressed in terms of universal master integral. We focus on the calculation of box diagrams and in particular on the removal of the ir infrared divergences. (author) 14 refs, 2 figs

  7. Investigation of a gas-catcher/ion guide system using alpha-decay recoil products

    CERN Document Server

    Peraejaervi, K; Rinta-Antila, S; Dendooven, P

    2002-01-01

    sup 2 sup 1 sup 9 Rn recoils from the alpha decay of sup 2 sup 2 sup 3 Ra have been used to study the efficiency and delay time distributions of a gas-catcher/ion guide system. Ions with charge states up to +4 were coming out of the gas cell. Combining efficiency and delay time measurements, ion survival times in plasma free conditions can be deduced.

  8. Alpha-decay energies of superheavy nuclei for the Fayans functional

    CERN Document Server

    Tolokonnikov, S V; Kortelainen, M; Lutostansky, Yu S; Saperstein, E E

    2016-01-01

    Alpha-decay energies for several chains of super-heavy nuclei are calculated by using Fayans functional FaNDF$^0$. They are compared to the experimental data and predictions of two Skyrme functionals, SLy4 and SkM*, and of the macro-micro method as well. The corresponding lifetimes are calculated with the use of the semi-phenomenological formulas by Parkhomenko and Sobiczewski and by Royer and Zhang.

  9. Amino acid sequence of phospholipase A/sub 2/-. cap alpha. from the venom of Crotalus adamanteus

    Energy Technology Data Exchange (ETDEWEB)

    Heinrikson, R.L.; Krueger, E.T.; Keim, P.S.

    1977-07-25

    The complete amino acid sequence of Crotalus adamanteus venom phospholipase A/sub 2/-..cap alpha.. has been determined by analysis of the five tryptic peptides from the citraconylated, reduced, and S-(/sup 14/C)carboxamidomethylated enzyme. Earlier studies provided the information necessary to align the tryptic fragments so that secondary cleavage procedures to establish overlaps were unnecessary. The subunit in the phospholipase A/sub 2/-..cap alpha.. dimer is a single polypeptide chain containing 122 amino acids and seven disulfide bonds. The histidine residue implicated in the active site of mammalian phospholipases is at position 47 in the C. adamanteus enzyme and is located in a domain of the molecule which is highly homologous in sequence with corresponding regions of phospholipases from a variety of venom and pancreatic sources. Comparative sequence analysis has revealed insights with regard to the function and evolution of phospholipases A/sub 2/. Primary structural relationships observed among the snake venom enzymes parallel the phylogenetic classification of the venomous reptiles from which they were derived. It is proposed that phospholipases A/sub 2/ of this general type be divided into two groups depending upon the presence or absence of distinctive structural features elucidated in this study.

  10. Electron double ionization cross section in sodium obtained from K. cap alpha. sup(h) hypersatellite spectra

    Energy Technology Data Exchange (ETDEWEB)

    Lahtinen, J.; Keski-Rahkonen, O. (Laboratory of Physics, Helsinki University of Technology, Espoo, Finland)

    1983-05-01

    The K..cap alpha..sup(h) hypersatellite spectrum of Na metal has been measured in electron excitation with voltages from 4 to 25 kV. The spectrum shows lines with initial K/sup -2/ (K..cap alpha../sub 2/sup(h)) and K/sup -2/L/sup -1/ holes. The energies of these lines as well as the K/sup 2/ binding energy have been determined and compared with theoretical calculations. The intensity of the line group with K/sup -2/L/sup -1/ initial configuration relative to the K/sup -2/ group has been measured and found to be in agreement with simple shake-off calculation. The electron double ionization cross section (EDC) of the K-shell has been determined from both thick and thin target measurements using the method developed by Saijonmaa and Keski-Rahkonen, and found to yield equivalent results. The EDC has also been calculated theoretically using classical and quantum mechanical binary encounter approximations as devised by Saijonmaa. Theory reproduces fairly well the magnitude and the atomic number dependence of the EDC whereas the shape of the EDC-curve as function of energy deviates clearly from observed values.

  11. Unified description of the proton, alpha, cluster decays and spontaneously fissions half- life

    CERN Document Server

    Mavrodiev, Strachimir Cht

    2016-01-01

    Some time ago the possibility of classical (without Gamow tunneling) universal description of radioactive nuclei decay was demonstrated. Such possibility is basis on the classical interpretation of Bohmian Psi-field reality in Bohmian-Chetaev mechanics and the hypothesis for the presence of dissipative forces, generated from the Gryzinski translational precession of the charged particles spin, in Langevin- Kramers diffusion mechanism. In this paper is present an unified model of proton, alpha decay, cluster radioactivity and spontaneous fission half-life as explicit function which depends on the total decay energy and kinetic energy, the number of protons and neutrons of daughter product, the number of protons and neutrons of mother nuclei and from a set) unknown digital parameters. The Half- lifes of the 573 nuclei taken from NuDat database together with the recent experimental data from Oganessian provide a basis for discovering the explicit form of the Kramers solution of Langevin type equation in a framew...

  12. Updated determination of $\\alpha_s(m_\\tau^2)$ from tau decays

    CERN Document Server

    Pich, Antonio

    2016-01-01

    Using the most recent release of the ALEPH $\\tau$ decay data, we present a very detailed phenomenological update of the $\\alpha_s(m_\\tau^2)$ determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find $\\alpha_{s}^{(n_f=3)}(m_\\tau^2) = 0.328 \\pm 0.012$ which implies $\\alpha_{s}^{(n_f=5)}(M_Z^{2}) = 0.1197\\pm 0.0014$. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values.

  13. O(alpha_s^2) corrections to fermionic Higgs decays in the MSSM

    CERN Document Server

    Mihaila, L

    2010-01-01

    We compute the two-loop corrections of O(alpha_s^2) to the Yukawa couplings in the framework of the Minimal Supersymmetric Standard Model (MSSM). The calculation is performed using the effective Lagrangian approach under the approximation of neglecting the Higgs boson mass with respect to the top quark, gluino and all squark flavour masses. As an application we derive the O(alpha_s^2) corrections to the partial decay width of the lightest Higgs boson to a bottom quark pair. We find that the two-loop corrections are sizable for large values of tan_beta and low CP-odd Higgs boson mass. With our calculation of the O(alpha_s^2) corrections the remaining theoretical uncertainties reduce below a few percent.

  14. Investigation of $\\alpha$-decay rates of $^{221}$Fr, $^{224}$Ra and $^{226}$Ra in different environments

    CERN Multimedia

    2007-01-01

    It has recently been suggested, and indicated experimentally, that $\\alpha$- decay half-lives are modified by solid state effects in the surrounding environment. We propose here to measure with high accuracy the $\\alpha$-decay half-life of $^{221}$Fr, $^{224}$Ra and $^{226}$Ra in insulators and metals. Furthermore we plan to investigate the temperature dependency of the half-life in these materials (room temperature, 4 K and 10 mK).

  15. Revisiting alpha decay-based near-light-speed particle propulsion.

    Science.gov (United States)

    Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu

    2016-08-01

    Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days. PMID:27161512

  16. Shape coexistence and shell-model intruder states in the lead region studied by $\\alpha$ -decay

    CERN Multimedia

    2002-01-01

    % IS336 \\\\ \\\\ Low-lying 0$^+$ states in even-even nuclei near closed shells can be a manifestation of the coexistence of different shapes in the same nucleus. Deformed bandstructures built upon these 0$^+$ states, coexisting at low energy with the ground state band, have been observed in several regions of the nuclear chart, including the Z=82 region. Such structures have been found in the neutron-deficient even Pb nuclei and the mixing between intruder and normal states has been studied by the $\\alpha$- decay of $^{194, 196, 198}$Po towards the 0$^+$ excited and ground states in $^{190, 192, 194}$Pb using $\\alpha$-e-t coincidence events. It is expected that shape coexistence will occur in the light Po isotopes as well. Evidence for a deformed band at low excitation energy in $^{196, 198}$Po has been found in in-beam studies and the $\\alpha$-decay of $^{202}$Rn studied at ISOLDE revealed feeding to a 0$^+$~state at 816~keV in $^{198}$Po. \\\\ \\\\It is our intention to investigate the $^{194, 196}$Po nuclei with ...

  17. Special features of photoelectromagnetic effect and properties of recombination centers in germanium single crystals irradiated by. cap alpha. particles

    Energy Technology Data Exchange (ETDEWEB)

    Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-01-01

    Results of studies on a spatial distribution of defects arising in Ge crystals following ..cap alpha..-particle (40 MeV) irradiation are given. The distribution of defects playing the role of recombination centres is shown to produce the definite effect on diffusion-recombination processes in semiconductors. The carrier capture cross section on recombination centres is determined to be sigma approximately 10/sup -15/ cm/sup -2/. A representation of recombination wall appearing in the vicinity of radiation defect concentration peak is introduced. The experimental data are compared with the developed theoretical representations. It is shown that studies on the photoelectromagnetic effect can give information both on the pattern of radiation defect spatial distribution and recombination parameters of irradiated semiconductors.

  18. Characteristics of the photelectromagnetic effect and properties of recombination centers in germanium single crystals irradiated with. cap alpha. particles

    Energy Technology Data Exchange (ETDEWEB)

    Babichenko, V.S.; Kikoin, L.I.; Lazarev, S.D.; Rzhanov, A.E.; Filippov, V.I.

    1984-01-01

    The spatial distribution of defects created in Ge crystals by irradiation with 40-MeV ..cap alpha.. particles was investigated. The distribution of the defects acting as recombination centers had a decisive influence on the diffusion-recombination processes in this semiconductor. The carrier-capture cross section of the recombination centers (sigmaapprox.10/sup -15/ cm/sup 2/) was determined. A concept of a recombination wall, which appeared in the region of a maximum of the radiation defect concentration, was introduced. The experimental data were compared with theoretical representations. This comparison demonstrated that an investigation of the photoelectromagnetic effect could give information both on the nature of the spatial distribution of radiation defects and on the recombination parameters of an irradiated semiconductor.

  19. Space distributions and decay probability for excited state of 7Li*(7,45 MeV) in reaction 7Li(alpha, alpha6Li)n

    International Nuclear Information System (INIS)

    Differential cross-sections of excitation and decay of 7Li*(7,45 MeV) resonance into 6Li + n channel in three particle reaction 7Li(alpha, alpha6Li)n at alpha-particle energy of 27,2 MeV have been determined in kinematically complete and incomplete experiments. Usage of position sensitive detector made it possible to obtain the data on space distributions of decay events for full range of possible angles and to determine the total probability of this process, which value essentially differs from the data for binary reactions. This result is agreed with previously obtained [1] and confirms the theoretical calculations [2] of decay branching ratio for short lived near-threshold resonances in three particle reactions

  20. Systematic Study on Alpha Decay Half-Lives of Superheavy Nuclei

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The α-decay half-lives of a set of superheavy nuclear isotope chain from Z = 105 to 120 have been analyzed systematically within the WKB method, and some nuclear structure features are found. The decay barriers have been determined in the quasi-molecular shape path within the Generalized Liquid Drop Model (GLDM) including the proximity effects between nucleons in a neck and the mass and charge asymmetry. The results are in reasonable agreement with the published experimental data for the alpha decay half-lives of isotopes of charge 112, 114, and 116, of the element 294118 and of some decay products. A comparison of present calculations with the results by the DDM3Y effective interaction and by the Viola-Seaborg-Sobiczewski (VSS) formulae is also made. The experimental α decay half lives all stand in between the GLDM calculations and VSS formula results. This demonstrates the possibility of these models to provide reasonable estimates for the half-lives of nuclear decays by α emissions for the domain of SHN. The half-lives of these new nuclei are thus well tested from the reasonable consistence of the macroscopic, the microscopic, the empirical formulae and the experimental data. This also shows that the present data of SHN themselves are consistent.It could suggest that the present experimental claims on the existence of new elements Z = 110 ~ 118 are reliable.It is expected that greater deviations of a few SHN between the data and the model may be eliminated by further improvements on the precision of the measurements.

  1. Weak phases $\\gamma$ and $\\alpha$ from $B^{+}$, or $B^{0}$ and $B_{s}$ decays

    CERN Document Server

    Gronau, Michael; Gronau, Michael; Pirjol, Dan

    1999-01-01

    An improved method is presented for determining the weak angle $\\gamma$ of the unitarity triangle using decay rates for $B^+\\to K\\pi, B^+\\to K^+\\bar K^0$ and $B^+\\to \\pi^+\\eta$ (or $B^0\\to K\\pi$ and $B_s\\to K \\pi$), their CP-conjugate modes and the CP-averaged rate for $B^\\pm\\to\\pi^\\pm\\pi^{0}$. Using SU(3) symmetry, the annihilation (color-suppressed) contribution in $B^+(B^0)\\to K\\pi$ decays is subtracted away. Electroweak penguin effects are included in a model-independent way. The only significant SU(3) breaking effects are accounted for in the factorization approximation of tree amplitudes. The weak angle $\\alpha$ is obtained as a byproduct.

  2. A Brief Review of Ultra-Rare Alpha Decay Detection Technique

    CERN Document Server

    Tsyganov, Yu S

    2006-01-01

    Three approaches to the measurement of a rare alpha decaying products produced in heavy-ion induced nuclear reactions are described. One is based on a chemical extraction and following deposition of the nuclides under investigation onto the surface of the detector, whereas the second one is associated with long-lived products implanted into silicon detectors by using the electromagnetic separation technique. The third approach relates with an application of real-time mode detection of correlated energy-time-position recoil-alpha sequences from $^{48}$Ca-induced nuclear reactions with actinide targets, like $^{242, 244}$Pu, $^{245,248}$Cm, $^{243}$Am, and $^{249}$Cf. Namely with this technique it has became possible to provide a radical suppression of backgrounds in the full fusion (3-5$n$) reactions aimed at the synthesis of superheavy elements with Z=113-118.

  3. GAMCAT - a personal computer database on alpha particles and gamma rays from radioactive decay

    International Nuclear Information System (INIS)

    The GAMCAT database is a compilation of data describing the alpha particles and gamma rays that occur in the radioactive decay of all known nuclides, adapted for IBM Personal Computers and compatible systems. These compiled data have been previously published, and are now available as a compact database. Entries can be retrieved by defining the properties of the parent nuclei as well as alpha-particle and gamma-ray energies or any combination of these parameters. The system provides fast access to the data and has been completely written in C to run on an AT-compatible computer, with a hard disk and 640K of memory under DOS 2.11 or higher. GAMCAT is available from the Fachinformationszentrum Karlsruhe. (orig.)

  4. Extended systematics of alpha decay half lives for exotic superheavy nuclei

    CERN Document Server

    Budaca, A I; Silisteanu, I

    2016-01-01

    The experimentally available data on the alpha decay half lives and Q? values for 96 superheavy nuclei are used to fix the parameters for a modified version of the Brown empirical formula through two fitting procedures which enables its comparison with similar fits using Viola-Seaborg and Royer formulas. The new expressions provide very good agreement with experimental data having fewer or the same number of parameters. All formulas with the obtained parameters are then extrapolated to generate half lives predictions for 125 unknown superheavy alpha emitters. The nuclei where the employed empirical formulas maximally or minimally diverge are pointed out and a selection of 36 nuclei with exceptional superposition of predictions was made for experimental reference.

  5. Predictions on the alpha decay chains of superheavy nuclei with Z =121 within the range 290 $\\leq$ A $\\leq$ 339

    CERN Document Server

    Santhosh, K P

    2016-01-01

    A systematic study on the alpha decay half lives of various isotopes of superheavy element \\textit{Z} = 121 within the range 290 $\\leq$ A $\\leq$ 339 is presented for the first time using Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated $\\alpha$ decay half lives of the isotopes within our formalism match well with the values computed using Viola-Seaborg systematic, Universal curve of Poenaru et al., and the analytical formula of Royer. In our study by comparing the $\\alpha$ decay half lives with the spontaneous fission half lives, we have predicted $2\\alpha$ chain from $^{309, 311, 312}$121, $3\\alpha$ chain from $^{310}$121 and $1\\alpha$ chain from $^{313, 314}$121. Clearly our study shows that the isotopes of superheavy element \\textit{Z} = 121 within the mass range 309 $\\leq$ A $\\leq$ 314 will survive fission and can be synthesized and detected in the laboratory via alpha decay. We hope that our predictions will provide a new guide to future experiments.

  6. Relativistic (Z alpha)^2-Corrections and Leading Quantum Electrodynamic Corrections to the Two-Photon Decay Rate of Ionic States

    CERN Document Server

    Wundt, B J; 10.1103/PhysRevA.80.022505

    2009-01-01

    We calculate the relativistic corrections of relative order (Z alpha)^2$ to the two-photon decay rate of higher excited S and D states in ionic atomic systems, and we also evaluate the leading radiative corrections of relative order alpha (Z alpha)^2 ln[(Z alpha)^(-2)]. We thus complete the theory of the two-photon decay rates up to relative order alpha^3 ln(alpha). An approach inspired by nonrelativistic quantum electrodynamics is used. We find that the corrections of relative order (Z alpha)^2 to the two-photon decay are given by the zitterbewegung, the spin-orbit coupling and by relativistic corrections to the electron mass, and by quadrupole interactions. We show that all corrections are separately gauge-invariant with respect to a "hybrid" transformation from velocity to length gauge, where the gauge transformation of the wave function is neglected. The corrections are evaluated for the two-photon decay from 2S, 3S, 3D, and 4S states in one-electron (hydrogenlike) systems, with 1S and 2S final states.

  7. Angular and velocity distributions of secondary particles emitted in interaction of 3. 6-GeV/nucleon. cap alpha. particles and lead nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Antonenko, V.G.; Vinogradov, A.A.; Galitskii, V.M.; Grigor' yan, Y.I.; Ippolitov, M.S.; Karadzhev, K.V.; Kuz' min, E.A.; Man' ko, V.I.; Ogloblin, A.A.; Paramonov, V.V.; Tsvetkov, A.A.

    1980-04-01

    The technique is described and results presented of measurements of the velocity and angular distributions of pions, protons, and deuterons, and tritons emitted in bombardment of lead nuclei by ..cap alpha.. particles with energy 3.6 GeV/nucleon.

  8. Effect of trihydroxyoctadecadienoic acids on blood levels of prostaglandins E/sub 2/ and F/sub 2. cap alpha. / and of 5-hydroxyeicosatetraenoic acid in rats with alloxan diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Vartanyan, G.S.; Panosyan, A.G.; Karagezyan, K.G.; Gevorkyan, G.A.

    1986-09-01

    The effect of the trihydroxyoctadecadienoic acids (THODA) fraction on blood levels of some eicosanoids and, in particular, of prostaglandins E/sub 2/ and F/sub 2..cap alpha../(PGE/sub 2/ and PGF/sub 2..cap alpha../), and 5-hydroxyeicosatetraenoic acid (5-HETE) in rats with alloxan diabetes was studied. Concentrations of PGE/sub 2/, PGF/sub 2..cap alpha../, and 5-HETE in peripheral blood plasma were determined by radioimmunoassay. To assess the loss of substances during extraction and chromatography, /sup 3/H/sub 8/-PGE/sub 2/, /sup 3/H/sub 8/-PGF/sub 2..cap alpha.., and /sup 3/H/sub 8/-5-HETE were used. Plasma PGE/sub 2/, PGF/sub 2..cap alpha../, and 5-HETE levels in albino rats with alloxan diabetes and after injection of THODA are shown.

  9. Radioimmunological determination of 5. cap alpha. -pregnane-3,20-dione in the peripheral venous blood of pregnant women showing pathological estriol values and/or HPL values or gestosis, on the basis of the gestational age. Radioimmunologische Bestimmung des 5. cap alpha. -Pregnan-3,20-dion im peripheren Venenblut schwangerer Frauen einer Gruppe mit pathologischen Oestriol- bzw. HPL-Werten und einer Gestosegruppe in Abhaengigkeit vom Gestationsalter

    Energy Technology Data Exchange (ETDEWEB)

    Klemm-Wolfgramm, E.

    1984-01-01

    A modified method of extraction and radioimmunological determination (iodine-125) is described, designed to monitor the concentrations of 5..cap alpha..-pregnandione (5..cap alpha..-DHP) in patients showing a pathological course of pregnancy and to examine the role of 5..cap alpha..-DHP blood levels in the development of gestosis. In this study, a control group was compared with two patient groups showing either (a) gestosis or (b) reduced levels of estriol and/or HPL. (1) In gestosis, the levels of 5..cap alpha..-DHP showed significant reductions that were proportionate to the degree of the disease, whereas decreases in these hormone levels were only observed to a minor extent in connection with pathological values of estriol and/or HPL. (2) The age of the patient had no influence on the hormone concentrations. (3) The increases in 5..cap alpha..-DHP seen in multiparae were only slight and did not attain any statistical significance. (4) No links were established between the concentrations of HPL and 5..cap alpha..-DHP in the maternal plasma and the development of the fetus. (5) Significantly reduced values of 5..cap alpha..-DHP were determined in mothers showing disorders of fetoplacental function (birth weights between 2500 and 3500 g) or gestosis (birth weights above 3500 g). (6) There were no relationships between the maternal serum levels of estriol, HPL and 5..cap alpha..-DHP and the sex of the fetus. (TRV).

  10. Updated Measurement of the CKM Angle alpha Using B0->rho+rho- Decays

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B

    2006-09-26

    The authors present results from an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} using 316 fb{sup -1} of {Upsilon}(4S) {yields} B{bar B} decays observed with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They measure the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} branching fraction, longitudinal polarization fraction f{sub L}, and the CP-violating parameters S{sub long} and C{sub long}: {Beta}(B{sup 0} {yields} {rho}{sup +}{rho}{sup -}) = (23.5 {+-} 2.2(stat) {+-} 4.1(syst)) x 10{sup -6}, f{sub L} = 0.977 {+-} 0.024(stat){sub -0.013}{sup +0.015}(syst), S{sub long} = -0.19 {+-} 0.21(stat){sub -0.07}{sup +0.05}(syst), C{sub long} = -0.07 {+-} 0.15(stat) {+-} 0.06(syst). Using an isospin analysis of B {yields} {rho}{rho} decays they determine the angle {alpha} of the unitarity triangle. One of the two solutions, {alpha} [74,117]{sup o} at 68% CL, is compatible with the standard model. All results presented here are preliminary.

  11. Experimental aspects of the adiabatic approach in estimating the effect of electron screening on alpha decay

    Energy Technology Data Exchange (ETDEWEB)

    Karpeshin, F. F., E-mail: fkarpeshin@gmail.com [D.I. Mendeleev Institute for Metrology (VNIIM) (Russian Federation); Trzhaskovskaya, M. B. [National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)

    2015-12-15

    Special features of the effect of the electron shell on alpha decay that have important experimental implications are studied within the adiabatic approach. The magnitude of the effect is about several tenths of a percent or smaller, depending on the transition energy and on the atomic number. A dominant role of inner shells is shown: more than 80% of the effect is saturated by 1s electrons. This circumstance plays a crucial role for experiments, making it possible to measure this small effect by a difference method in the same storage rings via a comparison of, for example, decay probabilities in bare nuclei and heliumlike ions. The reasons behind the relative success and the applicability limits of the frozen-shell model, which has been used to calculate the effect in question for more than half a century, are analyzed. An interesting experiment aimed at studying charged alpha-particle states is proposed. This experiment will furnish unique information for testing our ideas of the interplay of nonadiabatic and adiabatic processes.

  12. Swelling induced by alpha decay in monazite and zirconolite ceramics: A XRD and TEM comparative study

    Science.gov (United States)

    Deschanels, X.; Seydoux-Guillaume, A. M.; Magnin, V.; Mesbah, A.; Tribet, M.; Moloney, M. P.; Serruys, Y.; Peuget, S.

    2014-05-01

    Zirconolite and monazite matrices are potential ceramics for the containment of actinides (Np, Cm, Am, Pu) which are produced over the reprocessing of spent nuclear fuel. Actinides decay mainly through the emission of alpha particles, which in turn causes most ceramics to undergo structural and textural changes (amorphization and/or swelling). In order to study the effects of alpha decays on the above mentioned ceramics two parallel approaches were set up. The first involved the use of an external irradiation source, Au, which allowed the deposited recoil energy to be simulated. The second was based on short-lived actinide doping with 238Pu, (i.e. an internal source), via the incorporation of plutonium oxide into both the monazite and zirconolite structures during synthesis. In both types of irradiation experiments, the zirconolite samples became amorphous at room temperature with damage close to 0.3 dpa; corresponding to a critical dose of 4 × 1018 α g-1 (i.e. ∼1.3 × 1021 keV cm-3). Both zirconolite samples also showed the same degree of macroscopic swelling at saturation (∼6%), with ballistic processes being the predominant damaging effect. In the case of the monazite however, the macroscopic swelling and amorphization were dependent on the nature of the irradiation. Externally, (Au), irradiated samples became amorphous while also demonstrating a saturation swelling of up to 8%. In contrast to this, the swelling of the 238Pu doped samples was much smaller at ∼1%. Also, unlike the externally (Au) irradiated monazite these 238Pu doped samples remained crystalline up to 7.5 × 1018 α g-1 (0.8 dpa). XRD, TEM and swelling measurements were used to fully characterize and interpret this behavior. The low swelling and the conservation of the crystalline state of 238Pu doped monazite samples indicates that alpha annealing took place within this material.

  13. Drosophila casein kinase I alpha regulates homolog pairing and genome organization by modulating condensin II subunit Cap-H2 levels.

    Directory of Open Access Journals (Sweden)

    Huy Q Nguyen

    Full Text Available The spatial organization of chromosomes within interphase nuclei is important for gene expression and epigenetic inheritance. Although the extent of physical interaction between chromosomes and their degree of compaction varies during development and between different cell-types, it is unclear how regulation of chromosome interactions and compaction relate to spatial organization of genomes. Drosophila is an excellent model system for studying chromosomal interactions including homolog pairing. Recent work has shown that condensin II governs both interphase chromosome compaction and homolog pairing and condensin II activity is controlled by the turnover of its regulatory subunit Cap-H2. Specifically, Cap-H2 is a target of the SCFSlimb E3 ubiquitin-ligase which down-regulates Cap-H2 in order to maintain homologous chromosome pairing, chromosome length and proper nuclear organization. Here, we identify Casein Kinase I alpha (CK1α as an additional negative-regulator of Cap-H2. CK1α-depletion stabilizes Cap-H2 protein and results in an accumulation of Cap-H2 on chromosomes. Similar to Slimb mutation, CK1α depletion in cultured cells, larval salivary gland, and nurse cells results in several condensin II-dependent phenotypes including dispersal of centromeres, interphase chromosome compaction, and chromosome unpairing. Moreover, CK1α loss-of-function mutations dominantly suppress condensin II mutant phenotypes in vivo. Thus, CK1α facilitates Cap-H2 destruction and modulates nuclear organization by attenuating chromatin localized Cap-H2 protein.

  14. Alpha Decay Half-Lives of Some Nuclei from Ground State to Ground State with Yukawa Proximity Potential

    Institute of Scientific and Technical Information of China (English)

    E.Javadimanesh; H.Hassanabadi; A.A.Rajabi; H.Rahimov; S.Zarrinkamar

    2012-01-01

    We study the half-lives of some nuclei via the alpha-decay process from ground state to ground state. To go through the problem, we have considered a potential model with Yukawa proximity potential and have thereby calculated the half-lives. The comparison with the existing data is motivating.

  15. Measurement of the Strong Coupling Constant $\\alpha_s$ and the Vector and Axial-Vector Spectral Functions in Hadronic Tau Decays

    CERN Document Server

    Ackerstaff, K; Allison, J; Altekamp, N; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Bartoldus, R; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bird, S D; Blobel, Volker; Bloodworth, Ian J; Bobinski, M; Bock, P; Böhme, J; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brown, R M; Burckhart, Helfried J; Burgard, C; Bürgin, R; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Davis, R; De Jong, S; del Pozo, L A; de Roeck, A; Desch, Klaus; Dienes, B; Dixit, M S; Doucet, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Eatough, D; Estabrooks, P G; Etzion, E; Evans, H G; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Fiedler, F; Fierro, M; Fischer, H M; Fleck, I; Folman, R; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon, J; Gascon-Shotkin, S M; Geich-Gimbel, C; Geralis, T; Giacomelli, G; Giacomelli, P; Gibson, V; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Gross, E; Grunhaus, Jacob; Gruwé, M; Hanson, G G; Hansroul, M; Hapke, M; Hargrove, C K; Hartmann, C; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herndon, M; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hillier, S J; Hobson, P R; Höcker, Andreas; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Joly, A; Jones, C R; Jovanovic, P; Junk, T R; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Koetke, D S; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kyberd, P; Lafferty, G D; Lanske, D; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Lee, A M; Lefebvre, E; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mannelli, M; Marcellini, S; Markopoulos, C; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Menke, S; Merritt, F S; Mes, H; Meyer, J; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mir, R; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nellen, B; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Oreglia, M J; Orito, S; Pálinkás, J; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharf, F; Scharff-Hansen, P; Schieck, J; Schmitt, B; Schmitt, S; Schöning, A; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Sittler, A; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Sproston, M; Stahl, A; Stephens, K; Steuerer, J; Stoll, K; Strom, D; Ströhmer, R; Tafirout, R; Talbot, S D; Tanaka, S; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomson, M A; Von Törne, E; Torrence, E; Towers, S; Trigger, I; Trócsányi, Z L; Tsur, E; Turcot, A S; Turner-Watson, M F; Van Kooten, R; Vannerem, P; Verzocchi, M; Vikas, P; Voss, H; Wäckerle, F; Wagner, A; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Yekutieli, G; Zacek, V; Zer-Zion, D

    1999-01-01

    The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant alpha_s, the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives alpha_s(mtau**2) = 0.348 +- 0.009 +- 0.019 at the tau-mass scale and alpha_s(mz**2) = 0.1219 +- 0.0010 +- 0.0017 at the Z-mass scale. The values obtained for alpha_s(mz**2) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3% and 4.1% smaller, respectively. The running of the strong coupling between s_0 ~1.3 GeV**2 and s_0 = mtau**2 has been tested from direct fits to the integrated differential hadronic decay rate R_tau. A test of the saturation of QCD sum rules at the tau-mass scale has been...

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

    CERN Document Server

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

    2011-01-01

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

  17. cap alpha. -L-iduronidase deficiency in mucopolysaccharidosis type I against a radio-labelled sulfated disaccharide substrate derived from dermatan sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Muller, V.J.; Hopwood, J.J. (Department of Chemical Pathology, The Adelaide Children' s Hospital Inc., North Adelaide, South Australia)

    1984-01-01

    ..cap alpha..-L-Iduronidase activity was assayed by incubation of a radiolabelled disaccharide, O-(..cap alpha..-L-idopyranosyluronic acid)-(1 arrow 3)-2,5 anhydro-D-(1, /sup 3/H)-talitol 4-sulfate (IdoA-anT4S) derived from dermatan sulfate, with homogenates of leucocytes, cultured amniotic cells and skin fibroblasts from normal individuals and patients affected with an ..cap alpha..-L-iduronidase-deficiency disorder (mucopolysaccharidosis type I, MPS I), parents of such patients and patients affected with other mucopolysaccharidoses. The assay clearly distinguished affected homozygotes from normal controls, heterozygotes and other mucopolysaccharidosis types. Preliminary results show that fibroblast homogenates from patients with the MPS I Hurler phenotype were virtually unable to hydrolyse IdoA-anT4S, whereas fibroblast homogenates from a patient with a relatively mild (Scheie) phenotype exhibited a residual activity with Vsub(max) value of 2.5 pmol/min/mg protein and an apparent Ksub(m) of 21 ..mu..mol/l compared to a range of 1020-2105 pmol/min/mg for Vsub(max) and 12-35 ..mu..mol/l for Ksub(m) for fibroblasts from normal controls.

  18. Influence of prostaglandins E/sub 2/ and F/sub 2. cap alpha. / on the zinc transport across rat mid-intestine in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Song, M.K.; Adham, N.F.; Lee, D.B.N.; Carmack, C.R.

    1986-03-05

    Effects of physiological (5.0 ..mu..M) and pharmacological (50 ..mu..M) doses of prostaglandins (PG) E/sub 2/ and F/sub 2..cap alpha../ on the zinc transport rate across rat jejunum mounted on a Ussing Chamber were determined. Zinc transport rate from mucosal to serosal direction was 4.82 +/- 0.81 n moles/hr/cm/sup 2/ whereas the opposite direction was 18.71 +/- 0.96 n moles/hr/cm/sup 2/. When 5.0 ..mu..M or 50 ..mu..M PGE/sub 2/ or PGF/sub 2..cap alpha../ were added into Ringers-Krebs bicarbonate solution containing 3 mM L-histidine and 0.5 mM /sup 65/Zn Cl/sub 2/ to the mucosal side of mucosa, no significant difference in /sup 65/Zn transport rate was observed compared to controls. However, 5.0 ..mu..M PGF/sub 2..cap alpha../ and 50 ..mu..M PGE/sub 2/ significantly inhibited zinc transport from mucosal to serosal direction. When PGs were added to the opposite side of mucosa, only 5.0 ..mu..M PGs significantly inhibited zinc transport from serosal to mucosal direction. Results suggest that PGs act on the inhibition of zinc transport across the basolateral membrane of columnar absorbing cells and that 50 ..mu..M PGE/sub 2/ was the most powerful inhibitor.

  19. Systematic study of $\\alpha$ decay half-lives for even-even nuclei within a two-potential approach

    CERN Document Server

    Sun, Xiao-Dong; Li, Xiao-Hua

    2015-01-01

    $\\alpha$ decay is a common and important process for natural radioactivity of heavy and superheavy nuclei. The $\\alpha$ decay half-lives for even-even nuclei from Z=62 to Z=118 are systematically researched based on the two-potential approach with a quasi-stationary state approximation. To describe the deviations between experimental half-lives and calculated results due to the nuclear shell structure, a hindrance factor related with $\\alpha$ particle preformation probability is introduced. Our results can well reproduce the experimental data equally to the density-dependent cluster model and the generalized liquid drop model. We also study the isospin effect of nuclear potential in this work. Considering the isospin effect the calculated results improved about 7.3$\\%$.

  20. Predicting decay in free-radical concentration in L-. alpha. -alanine following high-LET radiation exposures

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, J.W. (Risoe National Lab., Roskilde (Denmark)); Olsen, K.J. (University Hospital of Copenhagen, Herlev (Denmark))

    1989-01-01

    Efforts have been made to develop a model that will predict time-dependent decay in radiation-induced free-radical concentration in L-{alpha}-alanine following heavy-charged-particle exposures. The decay rate depends on radiation quality, dose and dose-rate. For low doses, the decay-rate is approx. 0.5 and 1.5% per year following {sup 60}Co {gamma}-ray exposures and Linac-produced X-ray or electron exposures. Decay rates, however, have been found to increase as measured from low average doses, sparse single tracks, of heavy charged particles. We have compared measured decay after exposures to low average doses from high-LET particles with predicted decay calculated as function of particle velocity and charge and detector parameters. The predicted decay is obtained by folding measured decay after Linac-produced electron exposures of very high doses into the calculated dose distribution around the heavy ion's path. Preliminary results show agreement between the experimental data and results obtained from this model, within the experimental uncertainty. (author).

  1. The Higgs-Boson Decay $H\\to gg$ to Order $\\alpha_s^5$ under the mMOM-Scheme

    CERN Document Server

    Zeng, Dai-Min; Wu, Xing-Gang; Shen, Jian-Ming

    2015-01-01

    We study the decay width of the Higgs-boson $H\\to gg$ up to order $\\alpha_s^5$ under the minimal momentum space subtraction scheme (mMOM-scheme). To improve the accuracy of perturbative QCD prediction, we adopt the principle of maximum conformality (PMC) to set its renormalization scales. A detailed comparison of the total decay width and the separate decay widths at each perturbative order before and after the PMC scale setting is presented. The PMC adopts the renormalization group equation to fix the optimal scales of the process. After the PMC scale setting, the scale-dependence for both the total and the separate decay widths are greatly suppressed, and the convergence of perturbative QCD series is improved. By taking the Higgs mass $M_H=125.09\\pm 0.21\\pm 0.11$ GeV, as recently given by the ATLAS and CMS collaborations, we predict $\\Gamma(H\\to gg)|_{\\rm mMOM, PMC} = 339.1\\pm 1.7^{+4.0}_{-2.4}$ keV, where the first error is for Higgs mass and the second error is the residual scale dependence by varying the...

  2. A systematic study of proton, alpha and cluster decays in Rhenium isotopes using the effective liquid drop model

    Science.gov (United States)

    Joseph, Deepthy Maria; Ashok, Nithu; Joseph, Antony

    2016-01-01

    Employing the effective liquid drop model (ELDM), half-lives of proton and alpha decays and probable cluster decays are computed and analyzed for different proton-rich and neutron-rich isotopes of Rhenium. The investigation fortifies the phenomenon of cluster radioactivity (CR) in rare earth nuclei and also affirms the pivotal role played by neutron magicity in cluster decays. ELDM data is compared with that of universal decay law (UDL) model and found to be more efficient than the latter one. Apparently, cluster emissions slacken as the neutron number of daughter nucleus goes up and the linear nature of Geiger-Nuttall (G-N) plots stays unaltered even if the surface potential is incorporated.

  3. 1. cap alpha. ,25-Dihydroxyvitamin D/sub 3/ inhibits. gamma. -interferon synthesis by normal human peripheral blood lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.; Koeffler, H.P.; Tobler, A.; Norman, A.W.

    1987-05-01

    1..cap alpha..,25-Dihydroxyvitamin D/sub 3/ (1,25-(OH)/sub 2/D/sub 3/), the biologically active metabolite of vitamin D/sub 3/, inhibited synthesis of ..gamma..-interferon (IFN-..gamma..) by phytohemagglutinin-activated peripheral blood lymphocytes (PBLs). A significant reduction of IFN-..gamma.. protein levels in PBL culture medium was achieved with a physiologic 1,25-(OH)/sub 2/D/sub 3/ concentration, 1,25-(OH)/sub 2/D/sub 3/ also inhibited accumulation of IFN-..gamma.. mRNA in activated PBLs in a dose-dependent fashion. The ability of 1,25-(OH)/sub 2/D/sub 3/ to modulate IFN-..gamma.. protein synthesis was unaltered in the presence of high concentrations of recombinant human interleukin 2. The suppression of IFN-..gamma.. synthesis by PBLs was specific for 1,25-(OH)/sub 2/D/sub 3/; the potencies of other vitamin D/sub 3/ metabolites were correlated with their affinities for the cellular 1,25-(OH)/sub 2/D/sub 3/ receptor. The time course of 1,25-(OH)/sub 2/D/sub 3/ receptor expression in phytohemagglutinin-activated PBLs was correlated with the time course of 1,25-(OH)/sub 2/D/sub 3/-mediated inhibition of IFN-..gamma.. synthesis. Finally, the authors examined the effects of 1,25-(OH)/sub 2/D/sub 3/ on the constitutive IFN-..gamma.. production by two human T-lymphocyte lines transformed by human T-lymphotropic virus type I. The cell lines were established from a normal donor (cell line S-LB1) and from a patient with vitamin D-dependent rickets type 2 (cell line Ab-VDR). IFN-..gamma.. synthesis by S-LB1 cells was inhibited in a dose-dependent fashion by 1,25-(OH)/sub 2/D/sub 3/, whereas IFN-..gamma.. synthesis by Ab-VDR cells was not altered by 1,25-(OH)/sub 2/D/sub 3/. The data presented in this study provide evidence for a role of 1,25-(OH)/sub 2/D/sub 3/ in immunoregulation.

  4. [alpha]-Decay damage effects in curium-doped titanate ceramic containing sodium-free high-level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Mitamura, Hisayoshi; Matsumoto, Seiichiro; Tsuboi, Takashi; Hashimoto, Masaaki; Togashi, Yoshihiro; Kanazawa, Hiroyuki (Japan Atomic Energy Research Inst., Ibaraki (Japan)); Stewart, M.W.A.; Vance, E.R.; Hart, K.P.; Ball, C.J. (Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales (Australia). Lucas Heights Research Labs.); White, T.J.

    1994-09-01

    A polyphase titanate ceramic incorporating sodium-free simulated high-level nuclear waste was doped with 0.91 wt% of [sup 224]Cm to accelerate the effects of long-term self-irradiation arising from [alpha] decays. The ceramic included three main constituent minerals: hollandite, perovskite, and zirconolite, with some minor phases. Although hollandite showed the broadening of its X-ray diffraction lines and small lattice parameter changes during damage in growth, the unit cell was substantially unaltered. Perovskite and zirconolite, which are the primary hosts of curium, showed 2.7% and 2.6% expansions, respectively, of their unit cell volumes after a dose of 12 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1]. Volume swelling due to damage in growth caused an exponential (almost linear) decrease in density, which reached 1.7% after a dose of 12.4 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1]. Leach tests on samples that had incurred doses of 2.0 [times] 10[sup 17] and 4.5 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1] showed that the rates of dissolution of cesium and barium were similar to analogous leach rates from the equivalent cold ceramic, while strontium and calcium leach rates were 2--15 times higher. Although the cerium, molybdenum, strontium, and calcium leach rates in the present material were similar to those in the curium-doped sodium-bearing titanate ceramic reported previously, the cesium leach rate was 3--8 times lower.

  5. Measurement of the CKM Angle Alpha at the BABAR Detector Using B Meson Decays to Rho Final States

    Energy Technology Data Exchange (ETDEWEB)

    Mihalyi, Attila; /Wisconsin U., Madison

    2006-10-16

    This thesis contains the results of an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} using 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a fitted signal yield of 617 {+-} 52 events, the longitudinal polarizations fraction, f{sub L}, of the decay is measured to be 0.978 {+-} 0.014(stat){sub -0.029}{sup +0.021}(syst). The nearly fully longitudinal dominance of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay allows for a measurement of the time dependent CP parameters S{sub L} and C{sub L}, where the first parameter is sensitive to mixing induced CP violation and the second one to direct CP violation. From the same signal yield, these values are found to be S{sub L} = -0.33 {+-} 0.24(stat){sub -0.14}{sup +0.08}(syst) and C{sub L} = - 0.03 {+-} 0.18(stat) {+-} 0.09(syst). The CKM angle {alpha} is then determined, using these results and the branching fractions and polarizations of the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} and B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. This measurement is done with an isospin analysis, in which a triangle is constructed from the isospin amplitudes of these three decay modes. A {chi}{sup 2} expression that includes the measured quantities expressed as the lengths of the sides of the isospin triangles is constructed and minimized to determine a confidence level on {alpha}. Selecting the solution compatible with the Standard Model, one obtains {alpha} = 100{sup o} {+-} 13{sup o}.

  6. Biochemical studies of mouse brain tubulin: colchicine binding (DEAE-cellulose filter) assay and subunits (. cap alpha. and. beta. ) biosynthesis and degradation (in newborn brain)

    Energy Technology Data Exchange (ETDEWEB)

    Tse, Cek-Fyne

    1978-01-01

    A DEAE-cellulose filter assay, measuring (/sup 3/H)colchicine bound to colchicine binding protein (CBP) absorbed on filter discs, has been modified to include lM sucrose in the incubation medium for complexing colchicine to CBP in samples before applying the samples to filter discs (single point assay). Due to the much greater stability of colchicine binding capacity in the presence of lM sucrose, multiple time-point assays and least squares linear regression analysis were not necessary for accurate determination of CBP in hybrid mouse brain at different stages of development. The highest concentrations of CBP were observed in the 160,000g supernatant and pellet of newborn brain homogenate. Further studies of the modified filter assay documented that the assay has an overall counting efficiency of 27.3%, that DEAE-cellulose filters bind and retain all tubulin in the assay samples, and that one molecule of colchicine binds approximately one molecule of tubulin dimer. Therefore, millimoles of colchicine bound per milligram total protein can be used to calculate tubulin content. With this technique tubulin content of brain supernatant was found to be 11.9% for newborn, and 7.15% for 11 month old mice. Quantitative densitometry was also used to measure mouse brain supernatant actin content for these two stages. In vivo synthesis and degradation rates of tubulin ..cap alpha.. and ..beta.. subunits of two day mouse brain 100,000g supernatant were studied after intracerebral injection of (/sup 3/H)leucine. Quantitative changes of the ratio of tritium specific activities of tubulin ..cap alpha.. and ..beta.. subunits with time were determined. The pattern of change was biphasic. During the first phase the ratio decreased; during the second phase the ratio increased continuously. An interpretation consistent with all the data in this study is that the ..cap alpha.. subunit is synthesized at a more rapid rate than the ..beta.. subunit. (ERB)

  7. Non-statistical decay and $\\alpha$-correlations in the $^{12}$C+$^{12}$C fusion-evaporation reaction at 95 MeV

    CERN Document Server

    Morelli, L; D'Agostino, M; Gulminelli, F; Bruno, M; Abbondanno, U; Appannababu, S; Barlini, S; Bini, M; Casini, G; Cinausero, M; Degerlier, M; Fabris, D; Gelli, N; Gramegna, F; Kravchuk, V L; Marchi, T; Pasquali, G; Piantelli, S; Valdré, S; Raduta, Ad R

    2014-01-01

    Multiple alpha coincidence and correlations are studied in the reaction $^{12}$C+$^{12}$C at 95 MeV for fusion-evaporation events completely detected in charge. Two specific channels with Carbon and Oxygen residues in coincidence with $\\alpha$-particles are addressed, which are associated with anomalously high branching ratios with respect the predictions by Hauser-Feshbach calculations. Triple alpha emission appears kinematically compatible with a sequential emission from a highly excited Mg. The phase space distribution of $\\alpha$-$\\alpha$ coincidences suggests a correlated emission from a Mg compound, leaving an Oxygen residue excited above the threshold for neutron decay. These observations indicate a preferential $\\alpha$ emission of $^{24}$Mg at excitation energies well above the threshold for $6-\\alpha$ decay.

  8. Yields of Gamma- and X-Ray Radiation of Alpha-Decays of 235U

    International Nuclear Information System (INIS)

    Precise knowledge of gamma- and X-rays emission probabilities of uranium isotopes is vital for accurate gamma-spectrometric determination of the isotopic composition and quantity of uranium. The peak intensity ratio methods employing high resolution gammaspectrometry and intrinsic efficiency calibration approach are known to provide most accurate and reliable isotopic information. When applied to unshielded and moderately shielded material, these methods largely benefit from de-convolution of the 90-100 keV narrow spectral interval, which contains intense gamma- and X-ray lines of major uranium isotopes 235U and 238U. These are the 92.37 keV and 92.79 keV gamma-rays of 238U/234Th, and the 93.35 keV ThKα1 X-rays from alpha-decay of 235U. Although the emission probability ratios of these lines were accurately established, their absolute yields are still lacking accuracy. For instance, as resulted from recent study, the yields of 234Th lines become corrected by 30%, compared with their previous values. This consequently raised a question regarding validity of the yield data for the 93.35 keV line of 235U and triggered the present experimental study. This study was later extended to the reexamination of emission probabilities of other 235U gamma-lines with energies above 205 keV. The experimental data used in the current work was collected using SRM 969 and CRM 146 reference uranium samples. (author)

  9. Theoretical study on the properties of new nuclide sup 2 sup 7 sup 1 110 and its alpha-decay chain

    CERN Document Server

    Ren Zhong Zhou

    2002-01-01

    The structures of the nuclei on the alpha decay chain of sup 2 sup 7 sup 1 110 are investigated using self-consistent relativistic mean-field (RMF) model. The calculated alpha-decay energies are in good agreement with experimental data. The theoretical lifetimes reasonably agree with the data. The properties of sup 2 sup 7 sup 5 112 are predicted. A discussion on the deformed shell around Z = 108 is made

  10. /sup 45/Ca efflux for myometrial cells: comparison of the effects of prostaglandin F/sub 2/. cap alpha. (PGF/sub 2/), oxytocin (OT) and arachidonate (A)

    Energy Technology Data Exchange (ETDEWEB)

    Katona, G.; Molnar, M.; Toth, M.; Hertelendy, F.

    1986-03-01

    The aim of this study was to measure PGF/sub 2..cap alpha../-induced Ca/sup 2 +/ release from uterine cells and to compare this to the actions of OT and A. Smooth muscle cells isolated from the uterus (shell gland) of laying hens were cultured for 7 days in M199 plus 10% fetal calf serum. The cells were treated with digitonin (20..mu..M) and preloaded with /sup 45/Ca for 40 min. Addition of PGF/sub 2..cap alpha../ caused a biphasic /sup 45/Ca-efflux. There was a small but significant /sup 45/Ca-release within 30 sec (rapid phase) followed by a larger one within 7 min (slow phase). In comparison, both OT and A stimulated /sup 45/Ca efflux during a single, slow phase. The maximal effect of A was observed at < 7 min, whereas that of OT was slower, peaking after 7 min. Mepacrin, an inhibitor of A release, attenuated the action of OT without having any effect on A promoted /sup 45/Ca-efflux. Indomethacin, an inhibitor of PG synthase, failed to suppress the Ca-releasing effect of A suggesting the A itself or a lipoxygenase product may have been responsible for the observed effects. Moreover, these results provide suggestive evidence that A release is an important step in the action of various uterotonic agents converging on the mobilization of intracellular Ca.

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

    Energy Technology Data Exchange (ETDEWEB)

    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}.

  12. Study of the decay B0(B0bar)-->rho+rho-, and constraints on the CKM angle alpha

    CERN Document Server

    Aubert, Bernard; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Le Clerc, C; Lynch, G; Merchant, A M; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel, G; de Monchenault; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Convery, M R; Cristinziani, M; De, G; Nardo; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della, G; Ricca; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2004-01-01

    Using a data sample of 89 million Y(4s)-->B0B0bar decays collected with the BaBar detector at the PEP-II asymmetric B Factory at SLAC, we measure the B0(B0bar)-->rho+rho- branching fraction as $(30\\pm 4 stat \\pm 5 syst) \\times 10^{-6}$ and a longitudinal polarization fraction of $f_L = 0.99 \\pm 0.03 stat ^{+0.04}_{-0.03} syst$. We measure the time-dependent-asymmetry parameters of the longitudinally polarized component of this decay as $C_L = -0.17\\pm 0.27 stat \\pm 0.14 syst$ and ${S_L} = -0.42 \\pm 0.42 stat \\pm 0.14 syst$. We present constraints on the CKM angle $\\alpha$.

  13. Evidence for the B0->rho0rho0 Decay and Implications for the CKM Angle alpha

    CERN Document Server

    Aubert, B; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo-Sánchez, P; Barrett, M; Ford, K E; Hart, A J; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes,S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van, N; Bakel, M; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H; al, et

    2006-01-01

    We search for the decays B0->rho0rho0, B0->rho0f0, and B0->f0f0 in a sample of about 348 million Upsilon(4S)->BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find evidence for B0->rho0rho0 with 3.0 sigma significance and measure the branching fraction B = (1.16 +0.37-0.36 +-0.27) 10^{-6} and longitudinal polarization fraction f_L = 0.86 +0.11-0.13 +-0.05. As a consequence, the uncertainty on the CKM unitarity angle alpha due to penguin contributions in B->rhorho decays is estimated to be 18 degrees at 1 sigma level. We also set upper limits on the B0->rho0f0 and B0->f0f0 decay rates. All results are preliminary.

  14. Properties of the Alpha Decay Chain Nuclei of 310126, 292120 and 298114

    Institute of Scientific and Technical Information of China (English)

    WANG Ting-Tai; JIANG Wei-Zhou; ZHANG Wei; WANG Kun; ZHU Zhi-Yuan

    2004-01-01

    @@ The properties of the α decay nuclei of 310126, 292120 and 298 114 are investigated in the deformed relativistic meanfield model. The nuclear properties are investigated with the TMA and NL-Z2 parameter sets, and comparedwith Moller's result [At. Data Nucl. Data Tables 59 (1995) 185]. The results show that the α decay energy increases systematically with the increasing proton number. Meanwhile, the a decay energy has a minimum value at the point of shell closure. It is also found that among the three nuclei, 292120 is more possible to be the next doubly magic nucleus.

  15. Alpha Decay Preformation Factors for Even-Even 280-316116 Superheavy Isotopes

    Science.gov (United States)

    Alsaif, Norah A. M.; Radiman, Shahidan; Yahaya, Redzuwan; Ahmed, Saad M. Saleh

    2016-06-01

    The success of the cluster formation model (CFM) in deriving an energy-dependent formula for the preformation factors of heavy nuclei has motivated us to expand this approach to the superheavy isotopes (SHI). In this paper, the alpha-cluster formation (preformation factor) behavior inside the parent nuclei of SHI with atomic number Z = 116 and neutron numbers 164 ≤ N ≤ 200 is determined using the alpha preformation formula contained within the CFM. The cluster formation energy of the alpha particles and the total energy of the parent nuclei are calculated on the basis of the various binding energies. Our results clearly show that the CFM remains valid for superheavy nuclei (SHN). In addition, our calculations reveal that the alpha clustering mechanism and formation probability in 280-316116 even-even SHI are similar to those of even-even heavy nuclei in a general sense.

  16. New search for correlated e{sup +}e{sup -} pairs in the {alpha} decay of {sup 241}Am

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R.; Belli, P.; Di Marco, A. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); Cappella, F.; D' Angelo, A.; Incicchitti, A. [INFN, Sezione Roma, Rome (Italy); Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R.; Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Dai, C.J.; He, H.L.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy, IHEP, Beijing (China); Montecchia, F. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Ye, Z.P. [Chinese Academy, IHEP, Beijing (China); University of Jing Gangshan, Jiangxi (China)

    2013-05-15

    A new search for production of correlated e{sup +}e{sup -} pairs in the {alpha} decay of {sup 241}Am has been carried out deep underground at the Gran Sasso National Laboratory of the INFN by using pairs of NaI(Tl) detectors of the DAMA/LIBRA set-up. The experimental data show an excess of double coincidences of events with energy around 511keV in faced pairs of detectors, which are not explained by known side reactions. This measured excess gives a relative activity {lambda} = (4.70{+-}0.63) x 10{sup -9} for the Internal Pair Production (IPP) with respect to the alpha decay of {sup 241}Am; this value is of the same order of magnitude as previous determinations. In a conservative approach the upper limit {lambda} < 5.5 x 10{sup -9} (90% C.L.) can be derived. It is worth noting that this is the first result on IPP obtained in an underground experiment, and that the {lambda} value obtained in the present work is independent of the live-time estimate. (orig.)

  17. A Study of B0 to rho+rho- Decays and Constraints on the CKM Angle alpha

    CERN Document Server

    Aubert, B; Boutigny, D; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Eigen, G; Ofte, I; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schröder, T; Steinke, M; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F R; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Wright, D M; Lange D J; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Fisher, P H; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Lo Secco,J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Hartfiel, B L; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cenci, R

    2007-01-01

    We present results from an analysis of B0 to rho+rho- decays using 383.6 million BB-bar pairs collected by the BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. The measurements of the B0 to rho+rho- branching fraction, longitudinal polarization fraction f_L, and the CP-violating parameters S_{long} and C_{long} are: B(B0-> rho+rho-) = (25.5 +/- 2.1 (stat) +3.6/-3.9 (syst))*10^-6 f_L = 0.992 +/- 0.024 (stat) +0.026/-0.013 (syst) S_{long} = -0.17 +/- 0.20 (stat) +0.05/-0.06 (syst) C_{long} = 0.01 +/- 0.15 (stat) +/- 0.06 (syst) We determine the unitarity triangle angle alpha, using an isospin analysis of B to rhorho decays. One of the two solutions, alpha = [73.1, 117.0] degrees at 68% CL is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry based approach.

  18. A Study of B0 to rho+rho- Decays and Constraints on theCKM Angle alpha

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2007-05-16

    The authors present results from an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decays using (383.6 {+-} 4.2) x 10{sup 6} B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The measurements of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} branching fraction, longitudinal polarization fraction f{sub L}, and the CP-violating parameters S{sub long} and C{sub long} are: {Beta}(B{sup 0} {yields} {rho}{sup +}{rho}{sup -}) = (25.5 {+-} 2.1(stat){sub -3.9}{sup +3.6}(syst)) x 10{sup -6}, f{sub L} = 0.992 {+-} 0.024(stat){sub -0.013}{sup +0.026}(syst), S{sub long} = -0.17 {+-} 0.20(stat){sub -0.06}{sup +0.05}(syst), C{sub long} = 0.01 {+-} 0.15(stat) {+-} 0.06(syst). The authors determine the unitarity triangle angle {alpha}, using an isospin analysis of B {yields} {rho}{rho} decays. One of the two solutions, {alpha} = [73.1, 117.0]{sup o} at 68% CL is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry based approach.

  19. Alpha-decay studies of the new isotopes sup 1 sup 9 sup 1 At and sup 1 sup 9 sup 3 At

    CERN Document Server

    Kettunen, H; Grahn, T; Greenlees, P T; Jones, P; Julin, R; Juutinen, S; Keenan, A; Kuusiniemi, P; Leino, M; Leppaenen, A P; Nieminen, P; Pakarinen, J; Rahkila, P; Uusitalo, J

    2003-01-01

    Detailed alpha-decay studies have been performed for the neutron-deficient isotopes sup 1 sup 9 sup 1 At and sup 1 sup 9 sup 3 At. The nuclei were produced in fusion-evaporation reactions of sup 5 sup 4 Fe and sup 5 sup 6 Fe ions with a sup 1 sup 4 sup 1 Pr target. The fusion products were separated in-flight using a gas-filled recoil separator and implanted into a position-sensitive silicon detector. The isotopes were identified using position, time and energy correlations between the implants and subsequent alpha-decays. Three alpha-decaying states were identified for sup 1 sup 9 sup 3 At and two for sup 1 sup 9 sup 1 At. The spin and parity of the initial states in the astatine isotopes were deduced based on unhindered alpha-decays to states in the bismuth daughter nuclei. In both astatine isotopes the 1/2 sup + intruder state was determined to be the ground state and a 7/2 sup - state to be the first-excited state. In sup 1 sup 9 sup 3 At the alpha-decay of the 13/2 sup + state was observed in coincidence...

  20. Extractive separation of micro amounts of rhenium from molybdenite by quinoline and a modified method of rhenium determination by. cap alpha. -furyl-dioxime

    Energy Technology Data Exchange (ETDEWEB)

    Dorz, D.; Dobrowolski, J. (Politechnika Gdanska (Poland))

    1979-01-01

    The extractive separation of rhenium(7) by quinoline in alkaline solution as well as a modification of the spectrophotometric method for the determination of micro amounts of rhenium in a molybdenite from copper-molybdenum ores from Mongolia, using ..cap alpha..-furyldioxime has been developed. On the basis of the extractive separation method of perrhenate ion by quinoline from alkaline solution, rhenium has been determined in molybdenite. The molybdenite was decomposed by four different methods. Two of these decomposition methods, the fusion of Na/sub 2/O/sub 2/ with NaOH and the sintering of CaO with KMnO/sub 4/ were found as the best ones.

  1. Description of alpha decay and cluster radioactivity in the dinuclear system model

    Science.gov (United States)

    Kuklin, S. N.; Adamian, G. G.; Antonenko, N. V.

    2016-03-01

    A unified description of cluster radioactivity and α-decay of cold nuclei in the dinuclear system model is proposed. Quantum dynamical fluctuations along the charge (mass) asymmetry coordinate determine the spectroscopic factor, and tunneling along the relative distance coordinate determines the penetrability of the barrier of the nucleus-nucleus interaction potential. A new method for calculating the spectroscopic factor is proposed. The hindrance factors for the orbital angular momentum transfer are studied. A potential reason for the half-life to deviate from the Geiger-Nuttall law in α-decays of neutron-deficient nuclei 194, 196Rn is found. The fine structure of α-decays of U and Th isotopes is predicted and characterized. The model is used to describe α-decays from the rotational band of even-even nuclei. The known half-lives in the regions of "lead" and "tin" radioactivities are reproduced well, and the most probable cluster yields are predicted. The cluster decay of excited nuclei is discussed. The relation of cluster radioactivity to spontaneous fission and highly deformed nuclear states is analyzed.

  2. Alpha-particle emission probabilities in the decay of {sup 240}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Sibbens, G., E-mail: goedele.sibbens@ec.europa.e [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Pomme, S.; Altzitzoglou, T. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Garcia-Torano, E. [Laboratorio de Metrologia de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Janssen, H.; Dersch, R.; Ott, O. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Martin Sanchez, A. [Departamento de Fisica, Universidad de Extremadura, Badajoz, E-06071 (Spain); Rubio Montero, M.P. [Departamento de Fisica Aplicada, Universidad de Extremadura, Merida, Badajoz, E-06800 (Spain); Loidl, M. [Laboratoire National Henri Becquerel, LNE/CEA-LIST, 91191 Gif-sur-Yvette (France); Coron, N.; Marcillac, P. de [Institut d' Astrophysique Spatiale, CNRS, 91405 Orsay Campus (France); Semkow, T.M. [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States)

    2010-07-15

    Sources of enriched {sup 240}Pu were prepared by vacuum evaporation on quartz substrates. High-resolution alpha-particle spectrometry of {sup 240}Pu was performed with high statistical accuracy using silicon detectors and with low statistical accuracy using a bolometer. The alpha-particle emission probabilities of six transitions were derived from the spectra and compared with literature values. Additionally, some alpha-particle emission probabilities were derived from {gamma}-ray intensity measurements with a high-purity germanium detector. The alpha-particle emission probabilities of the three main transitions at 5168.1, 5123.6 and 5021.2 keV were derived from seven aggregate spectra analysed with five different fit functions and the results were compatible with evaluated data. Two additional weak peaks at 4863.5 and 4492.0 keV were fitted separately, using the exponential of a polynomial function to represent the underlying tailing of the larger peaks. The peak at 4655 keV could not be detected by alpha-particle spectrometry, while {gamma}-ray spectrometry confirms that its intensity is much lower than expected from literature.

  3. Ground State Properties of New Element Z = 113 and Its Alpha Decay Chain

    Institute of Scientific and Technical Information of China (English)

    TAI Fei; CHEN Ding-Han; XU Chang; REN Zhong-Zhou

    2005-01-01

    @@ We investigate the ground state properties of the new element 278113 and of the α-decay chain with different models, where the new element Z = 113 has been produced at RIKEN in Japan by cold-fusion reaction [Morita et al.J.Phys.Soc.Jpn.73 (2004) 2593].The experimental decay energies are reproduced by the deformed relativistic mean-field model, by the Skyrme-Hartree-Fock (SHF) model, and by the macroscopic-microscopic model.Theoretical half-lives also reasonably agree with the data.Calculations further show that prolate deformation is important for the ground states of the nuclei in the α-decay chain of 278113.The common points and differences among different models are compared and discussed.

  4. Scalar correlator at [symbol: see text](alpha(s)4), Higgs boson decay into bottom quarks, and bounds on the light-quark masses.

    Science.gov (United States)

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

    2006-01-13

    We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications, we consider the [symbol: see text](alpha(s)4) corrections to the decay rate of the standard model Higgs boson into quarks, as well as the constraints on the strange quark mass following from QCD sum rules.

  5. Predictions on the alpha decay half lives of superheavy nuclei with Z = 113 in the range 255 ≤ A ≤ 314

    Science.gov (United States)

    Santhosh, K. P.; Augustine, A.; Nithya, C.; Priyanka, B.

    2016-07-01

    An intense study of the alpha decay properties of the isotopes on superheavy element with Z = 113 has been performed within the Coulomb and proximity potential model for deformed nuclei (CPPMDN) within the wide range 255 ≤ A ≤ 314. The predicted alpha decay half lives of 278113 and 282113 and the alpha half lives of their decay products are in good agreement with the experimental data. 6α chains and 4α chains predicted respectively for 278113 and 282113 are in agreement with the experimental observation. Our study shows that the isotopes in the mass range 278 ≤ A ≤ 286 will survive fission and can be synthesized and detected in the laboratory via alpha decay. In our study, we have predicted 6α chains from 279113, 4α chains from 286113, 3α chains from 280,281,283113, 2α chains from 284113 and 1α chain from 285113. We hope that these predictions will be a guideline for future experimental investigations.

  6. Search for shape coexistence in {sup 188,190}Pb via fine structure in the alpha decay of {sup 192,194}Po

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Davids, C.; Janssens, R.V.F. [and others

    1995-08-01

    The interaction between coexisting shapes in nuclei near closed shells was of great interest in the past decade. Excited 0{sup +} states at low energy can often be identified as the bandheads of structures with differing shapes built on those states, These structures were identified in {sup 190-198}Pb via beta decay and alpha decay {open_quotes}fine structure{close_quotes} studies. Coexistence of different shapes in Pb nuclei was predicted by Nilsson-Strutinsky calculations, in which both the oblate and prolate minima were predicted to have excitation energies near 1 MeV. It was our intention to continue the systematic study of the Pb nuclides by searching for excited O{sup +} states in {sup 188}Pb by observing the fine structure in the alpha decay of {sup 192}Po.

  7. Alpha decay in electron environments of increasing density: From the bare nucleus to compressed matter

    Energy Technology Data Exchange (ETDEWEB)

    Belloni, Fabio [Institute for Transuranium Elements, European Commission, Joint Research Centre, Postfach 2340, Karlsruhe (Germany)

    2016-02-15

    The influence of the electron environment on the α decay is elucidated. Within the frame of a simple model based on the generalized Thomas-Fermi theory of the atom, it is shown that the increase of the electron density around the parent nucleus drives a mechanism which shortens the lifetime. Numerical results are provided for {sup 144}Nd, {sup 154}Yb and {sup 210}Po. Depending on the nuclide, fractional lifetime reduction relative to the bare nucleus is of the order of 0.1-1% in free ions, neutral atoms and ordinary matter, but may reach up to 10% at matter densities as high as 10{sup 4}g/cm{sup 3}, in a high-Z matrix. The effect induced by means of state-of-the-art compression techniques, although much smaller than previously found, would however be measurable. The extent of the effect in ultra-high-density stellar environments might become significant and would deserve further investigation. (orig.)

  8. From beta-relaxation to alpha-decay: Atomistic picture from molecular dynamics simulations for glass-forming Ni0.5Zr0.5 melt

    International Nuclear Information System (INIS)

    In glass-forming melts the decay of structural fluctuation shows the well known transition from beta-relaxation (von-Schweidler law with exponent b) to alpha-decay (KWW law with exponent beta). Here we present results from molecular dynamics simulations for a metallic glass forming Ni0.5Zr0.5 model aimed at giving an understanding of this transition on the atomistic scale. At the considered temperature below mode coupling Tc, the dynamics of the system can be interpreted by residence of the particles in their neighbour cages and escape from the cages as rare processes. Our analysis yields that the fraction of residing particles is characterized by a hierarchical law in time, with von-Schweidler b explicitly related to the exponent of this law. In the alpha-decay regime the stretching exponent reflects, in addition, floating of the cages due to strain effects of escaped particles. Accordingly, the change from beta-relaxation to alpha-decay indicates the transition from low to large fraction of escaped particles.

  9. Feasibility of observing the {\\alpha} decay chains from isotopes of SHN with Z = 128, Z = 126, Z = 124 and Z = 122

    CERN Document Server

    Santhosh, K P; Nithya, C

    2016-01-01

    Taking the Coulomb and proximity potential model for deformed nuclei (CPPMDN) as the interacting potential for the post-scission region, the alpha decay properties of 34 isotopes of the superheavy nuclei with Z = 128 within the range 306 $\\leq$ A $\\leq$ 339 have been studied, considering both the parent and daughter nuclei to be deformed. The manuscript also deals with the decay properties of the isotopes of Z = 126 (within 288 $\\leq$ A $\\leq$ 339), Z = 124 (within 284 $\\leq$A $\\leq$ 339) and Z = 122 (within 280 $\\leq$ A $\\leq$ 339). The alpha decay half lives thus evaluated has been compared with the values evaluated using other theoretical models and it was seen that, our theoretical alpha decay half lives matches well with these values. Through the present study, we have underlined and have established the fact that, among the 192 isotopes considered in the present study, only those isotopes $^{321-324,328-335}$128, $^{318-320,323-327}$126, $^{305-308,315-322}$124 and $^{298-307,311-314}$122 can be synthes...

  10. A study of the recombination scheme dependence of jet production rates and of. alpha. sub s (Msub(Z sub 0 )) in hadronic Z sup 0 decays

    Energy Technology Data Exchange (ETDEWEB)

    Akrawy, M.Z.; Alexander, G.; Allison, J.; Allport, P.P.; Anderson, K.J.; Armitage, J.C.; Arnison, G.T.J.; Ashton, P.; Azuelos, G.; Baines, J.T.M.; Ball, A.H.; Banks, J.; Barker, G.J.; Barlow, R.J.; Batley, J.R.; Beck, A.; Becker, J.; Behnke, T.; Bell, K.W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I.J.; Bock, P.; Breuker, H.; Brown, R.M.; Brun, R.; Buijs, A.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Chrin, J.T.M.; Clarke, P.E.L.; Cohen, I.; Collins, W.J.; Conboy, J.E.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G.M.; Debu, P.; Deninno, M.M.; Dieckmann, A.; Dittmar, M.; Dixit, M.S.; Duchovni, E.; Duerdoth, I.P.; Dumans, D.J.P.; Elcombe, P.A.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fischer, H.M.; Fong, D.G.; French, M.T.; Fukunaga, C.; Gaidot, A.; Ganel, O.; Gary, J.W.; Gascon, J.; Geddes, N.I.; Gee, C.N.P.; Geich-Gimbel, C.; Gensler, S.W.; Gentit, F.X.; Giacomelli, G.; G; OPAL Collaboration

    1991-02-01

    Jet production rates in hadronic Z{sup 0} decays are studied using four different recombination schemes to define resolvable jets. The strong coupling constant {alpha}{sub s}(Msub(Z{sup 0})) is determined in fits of the corresponding O({alpha}{sub s}{sup 2}) QCD calculations to the differential 2-jet distributions D{sub 2}(y). Hadronisation corrections and renormalisation scale uncertainties are found to be different for each recombination scheme. Within their overall systematic uncertainties, the four schemes yield consistent values of {alpha}{sub s}(Msub(Z{sup 0})), leading to a final result of {alpha}{sub s}(Msub(Z{sup 0}))=0.118{plus minus}0.008. The error includes the experimental uncertainties ({plus minus}0.003), uncertainties of hadronisation corrections and of the degree of parton virtualities to which the data are corrected, as well as the uncertainty of choosing the renormalisation scale. (orig.).

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

    CERN Document Server

    Simakin, A V

    2011-01-01

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

  12. Properties of Z=120 nuclei and the \\alpha-decay chains of the (292,304)120 isotopes using relativistic and non-relativistic formalisms

    CERN Document Server

    Ahamad, Shakeb; Patra, S K

    2012-01-01

    The ground state and first intrinsic excited state of superheavy nuclei with Z=120 and N=160-204 are investigated using both non-relativistic Skyrme-Hartree-Fock and the axially deformed Relativistic Mean Field formalisms. We employ a simple BCS pairing approach for calculating the energy contribution from pairing interaction. The results for isotopic chain of binding energy, quadrupole deformation parameter, two neutron separation energies and some other observables are compared with the FRDM and some recent macroscopic-microscopic calculations. We predict superdeformed ground state solutions for almost all the isotopes. Considering the possibility of magic neutron number, two different mode of \\alpha-decay chains (292)120 and (304)120 are also studied within these frameworks. The Q_{\\alpha}-values and the half-life T^{\\alpha}_{1/2} for these two different mode of decay chains are compared with FRDM and recent macroscopic-microscopic calculations. The calculation is extended for the \\alpha-decay chains of 29...

  13. Synthesis of biological markers in fossil fuels. 4. C/sub 27/, C/sub 28/, and C/sub 29/ 13. beta. ,17. cap alpha. (H)-diasteranes

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, P.E.; Nelson, D.A.; Watt, D.S.; Reibenspies, J.H.; Anderson, O.P.; Seifert, W.K.; Moldowan, J.M.

    1985-12-27

    The rearrangement of 5-cholestene to (20epsilon)-13(17)-diacholestenes, separation of C-20 epimers, and further reduction provided an unambiguous synthesis of the biomarkers (20R)- and (20S)-13..beta..,17..cap alpha..(H)-diacholestanes. Repetition of this sequence using (24R)-5-campestene or (24R)-5-stigmastene provided the analogous C/sub 28/ and C/sub 29/ diasteranes. 15 references, 1 figure.

  14. Probing the statistical decay and alpha-clustering effects in 12c+12c and 14n+10b reactions

    CERN Document Server

    Morelli, Luca; Agostino, M D; Bruno, M; Gulminelli, F; Cinausero, M; Degerlier, M; Fabris, D; Gramegna, F; Marchi, T; Barlini, S; Bini, M; Casini, G; Gelli, N; Lopez, A; Pasquali, G; Piantelli, S; Valdre', S

    2013-01-01

    An experimental campaign has been undertaken at INFN Laboratori Nazionali di Legnaro, Italy, in order to progress in our understanding of the statistical properties of light nuclei at excitation energies above particle emission threshold, by measuring exclusive data from fusion-evaporation reactions. A first reaction 12C+12C at 7.9 AMeV beam energy has been measured, using the GARFIELD+Ring Counter experimental setup. Fusion-evaporation events have been exclusively selected. The comparison to a dedicated Hauser-Feshbach calculation allows us to give constraints on the nuclear level density at high excitation energy for light systems ranging from C up to Mg. Out-of-equilibrium emission has been evidenced and attributed both to entrance channel effects favoured by the cluster nature of reaction partners and, in more dissipative events, to the persistence of cluster correlations well above the 24Mg threshold for 6 alphas decay. The 24Mg compound nucleus has been studied with a new measurement 14N + 10B at 5.7 AM...

  15. Effect of. cap alpha. -tocopherol, butylated-hydroxytoluene and hydroxy-anisole on the activation and binding of aflatoxin B/sub 1/ to macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ch' ih, J.J.; Biedrzycka, D.; Devlin, T.M.

    1987-05-01

    The anti-oxidants, ..cap alpha..-tocopherol(TPA), butylated-hydroxy-toluene(BHT) and hydroxyanisole(BHA) inhibit the carcinogenic and toxic effects of a variety of chemical compounds, their effect on aflatoxin B/sub 1/ (AFB/sub 1/) activation and binding was examined utilizing rat liver microsomes and cells. With a NADPH generating system, oxygen, microsomes, (/sup 3/H)-AFB/sub 1/, 2.2 pmoles/h/mg protein was activated and bound to macromolecules. In hepatocytes, 3.4 and 1.4 pmoles of AFB/sub 1/ per 10/sup 6/ cells were taken up and bound to macromolecules, whereas the nucleic acid fraction contained 0.19 pmoles of bound AFB/sub 1/. Moderate decreases of AFB/sub 1/ activation and binding were observed when TPA was present in both cell-free and hepatocytes systems. Only in hepatocytes, BHT inhibited the AFB/sub 1/ uptake and binding to nucleic acids. BHA, however, inhibited microsomal activation of AFB/sub 1/ by 73%; maximum inhibition was reached at 1 mM. AFB/sub 1/ uptake, and binding to nucleic acids were inhibited by 65% and 79% by BHA. GSH-transferase activity of cells treated with these agents was not altered. The effect of BHA at various concentrations on AFB activation was compared with cytochrome P-450 inhibitors; the ED/sub 50/ of SKF 525A, BHA and metyrapone was 9 uM, 80 uM and 380 uM respectively. The data suggest that TPA, BHA and BHT exert their effect by different mechanisms.

  16. Experimental determination of prompt neutron decay constant of IPEN/MB-01 reactor by Rossi-{alpha} method; Determinacao experimental da constante de decaimento de neutrons prontos do reator IPEN/MB-01 via o metodo Rossi-{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, Renato; Santos, Adimir dos; Jerez, Rogerio; Bitelli, Ulysses D' Utra; Diniz, Ricardo; Madi, Tufic [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ryrkuram@ipen.br

    2005-07-01

    One major objective of this work is to experimentally estimate the prompt neutron decay constant, {alpha}, on the IPEN/MB-01 research reactor at Sao Paulo. In order to achieve our goal, we will use a microscopic noise technique called Rossi-{alpha} method. This method is based on the statistical nature of the fission-chain process. Using a coincidence acquisition system, the rationale is to experimentally determine the probability distribution of detecting neutrons from the same chain. Through a leastsquares fit of this distribution we estimate {alpha}=({beta}{sub eff}-{rho})/{lambda}. The {alpha} parameter will be measured for different sub-critical levels, and the ratio {beta}{sub eff}/{lambda} is obtained via extrapolation to {rho}=0. A specific acquisition system for Rossi-{alpha} measurements has been developed in order to achieve our objective. This system is based on a multichannel scaler controlled by virtual instruments that records the timing of all neutron events, allowing data analysis during the acquisition. The first measurements were performed using one BF{sub 3} detectors positioned at the center of the core of IPEN/MB-01 research reactor. In this work we will present a preliminary set of Rossi-{alpha} measurements performed on the IPEN/MB-01 research reactor at Sao Paulo. (author)

  17. Probing the charged Higgs quantum numbers through the decay H{sup +}{sub {alpha}} {yields} W{sup +}h{sup 0}{sub s}s

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Cruz, J L [Cuerpo Academico de PartIculas, Campos y Relatividad de la BUAP (Mexico); Felix-Beltran, O [Instituto de Fisica, UNAM, Apdo. Postal 20-364, Mexico 01000 D.F. (Mexico); Hernandez-Sanchez, J [Universidad Autonoma del Estado de Hidalgo, Carretera a Pachuca Tulancingo Km. 4.5, C. U., C.P. 42020, Pachuca Hidalgo (Mexico); Barradas-Guevara, E [Cuerpo Academico de PartIculas, Campos y Relatividad de la BUAP (Mexico)

    2006-05-15

    The vertex H{sup +}{sub {alpha}} {yields} W{sup -}h{sup 0}{sub s}s, involving the gauge boson W{sup {+-}} and the charged (H{sup {+-}}{sub {alpha}}) and neutral Higgs bosons (h{sup 0}{sub s}s), arises within the context of many extensions of the SM, and it can be used to probe the quantum numbers of the Higgs multiplet. After presenting a general discussion for the expected form of this vertex for arbitrary Higgs representations, we discuss its strength for an extended MSSM with one complex triplet. We find that in this model, there are regions of parameters where the decay H{sup +}{sub {alpha}} {yields} W{sup +}h{sup 0}{sub s}s, is kinematically allowed, and reaches Branching Ratios (BR) that may be detectable, thus allowing to test the properties of the Higgs sector.

  18. Thermal desorption gas chromatography and positron annihilation spectroscopy, contribution to alpha decay studies in actinide-doped matrices

    Energy Technology Data Exchange (ETDEWEB)

    Roudil, D.; Jegou, C.; Vella, F.; Folch, B.; Broudic, V. [Commissariat a l' energie Atomique, Rhone Valley Research Center, 30200 Bagnols-sur-Ceze (France); Pik, R. [CNRS-CRPG, 54506 Vandoeuvre-les-Nancy (France); Barthe, M. F. [CNRS-CEMHTI, 45071 Orleans (France); Cuney, M. [Universite de Nancy, CNRS, CREGU, 54506 Vandoeuvre-les-Nancy (France); Pipon, Y. [IPNL CNRS, IN2P3 UMR 5822, 69622 Villeurbanne (France)

    2009-07-01

    A thermal desorption system coupled with a gas analyzer has been adapted and nuclearized to investigate He behavior in actinide-doped samples used to simulate alpha decay aging. This technique widely used in standard laboratories allows measurements of the helium balance and reduced diffusion coefficients, and a preliminary evaluation of helium locations (related to defects and thermal annealing). In our system implemented in a hot cell, small samples are annealed at up to 1100 C degrees in controlled atmosphere. They are inserted in a 10 to 20 cm{sup 3} vessel connected to a micro gas chromatography detector. Initial system calibration allowed concentration measurements within about 10%. Comparisons with the CNRS/CRPG rare gas analysis laboratory at Nancy (France) were applied on natural uranium oxides originating from Oklo (Gabon) and Mistamisk (Canada). The latest results obtained on Mistamisk samples are in good agreement, with a maximum relative deviation of 14%. The data were used to determine the activation energy of about 1 eV.at{sup -1}. On (U,Pu)O{sub 2} and PuO{sub 2} samples the experiments highlight the impact of defects (up to 100 dpa) on He mobility. The defect population must now be characterized to improve our knowledge of He/defect interactions and mechanisms. In addition and synergy to the macroscopic release measurements by gas chromatography, positron annihilation spectroscopy, an effective nondestructive technique for vacancy defect investigation, was also developed and nuclearized in our hot cell laboratory as part of a project supported by the NOMADE and MATINEX research groups. Specific protocols for doped sample analysis were also developed and validated with UO{sub 2} and (U,Pu)O{sub 2} samples. (authors)

  19. Systematic study of favored \\alpha-decay half-lives of closed shell odd-A and doubly-odd nuclei related to ground and isomeric states

    CERN Document Server

    Sun, Xiao-Dong; Li, Xiao-Hua

    2016-01-01

    In this work, we systematically investigate the favored $\\alpha$-decay half-lives and $\\alpha$ preformation probabilities of both odd-$A$ and doubly-odd nuclei related to ground and isomeric states around the doubly magic cores at $Z=82$, $N=82$ and at $Z=82$, $N=126$, respectively, within a two-potential approach from the view of the valence nucleon (or hole). The results show that the $\\alpha$ preformation probability is linear related to $N_\\text{p}N_\\text{n}$ or $N_\\text{p}N_\\text{n}I$, where $N_\\text{p}$, $N_\\text{n}$, and $I$ are the number of valence protons (or holes), the number of valence neutrons (or holes), and the isospin of the parent nucleus, respectively. Fitting the $\\alpha$ preformation probabilities data extracted from the differences between experimental data and calculated half-lives without a shell correction, we give two analytic formulas of the $\\alpha$ preformation probabilities and the values of corresponding parameters. Using those formulas and the parameters, we calculate the $\\alp...

  20. Competition between alpha-decay and spontaneous fission at isotopes of superheavy elements Rf, Db, and Sg

    Energy Technology Data Exchange (ETDEWEB)

    Anghel, Claudia Ioana, E-mail: claudia.anghel@theory.nipne.ro [Department of Theoretical Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele, P.O.Box MG-6, RO-077125 (Romania); University of Bucharest, Faculty of Physics, RO-077125 Bucharest - Magurele (Romania); Silisteanu, Andrei Octavian [Radiopharmaceutical Research Center, Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele, P.O.Box MG-6, RO-077125 (Romania)

    2015-12-07

    The most important decay modes for heavy and superheavy nuclei are their α-decay and spontaneous fission. This work investigates the evolution and the competition of these decay modes in long isotopic sequences. The partial half-lives are given by minimal sets of parameters extracted from the fit of experimental data and theoretical results. A summary of the experimental and calculated α-decay and spontaneous fission half-lives of the isotopes of elements Rf, Db, and Sg is presented. Some half-life extrapolations for nuclides not yet known are also obtained.

  1. Competition between alpha-decay and spontaneous fission at isotopes of superheavy elements Rf, Db, and Sg

    International Nuclear Information System (INIS)

    The most important decay modes for heavy and superheavy nuclei are their α-decay and spontaneous fission. This work investigates the evolution and the competition of these decay modes in long isotopic sequences. The partial half-lives are given by minimal sets of parameters extracted from the fit of experimental data and theoretical results. A summary of the experimental and calculated α-decay and spontaneous fission half-lives of the isotopes of elements Rf, Db, and Sg is presented. Some half-life extrapolations for nuclides not yet known are also obtained

  2. Alpha-decay branching ratios to high-lying excited-states of the 242Cm→238pu→ 234U →230Th→226Rn decay chain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin-Juan; XU Chang; REN Zhong-Zhou

    2009-01-01

    We present a systematic calculation on the 0c-decay branching ratios to excited-states of an even-even α-decay chain 242Cm→238pu→234U →230Th→226Rn by the improved barrier penetration approach. The changes of the parities between the parent nuclei and the daughter nuclei are properly taken into account. The theoretical values are compared with the available experimental data and the deviation between them is within a factor of 5 in most cases.

  3. Improving the measurement of the CKM phase $\\phi_2 = \\alpha$ in $B \\to \\pi \\pi$ and $B \\to \\rho \\rho$ decays

    CERN Document Server

    Gronau, Michael

    2016-01-01

    CP-violating asymmetries in $B \\to \\pi \\pi$ and $B \\to \\rho \\rho$ decays can help specify the weak phase $\\phi_2 = \\alpha$ of the Cabibbo-Kobayashi-% Maskawa (CKM) matrix. We discuss the impact of improved measurements of these processes such as will be available in the near future, finding special value in better measurement of the time-dependent CP violation parameter $S_{00}$ in $B^0 \\to \\pi^0 \\pi^0$ and $B^0 \\to \\rho^0 \\rho^0$. Reducing the errors on $B \\to \\rho \\rho$ measurements by a factor of two can potentially lead to an error in $\\phi_2 = \\alpha$ just above $2^\\circ$, at which level isospin-breaking corrections must be considered.

  4. Study of alpha decay chains of superheavy nuclei and magic number beyond Z = 82 and N = 126

    International Nuclear Information System (INIS)

    We study various α-decay chains on the basis of the preformed cluster decay model. Our work targets the superheavy elements, which are expected to show extra stability at shell closure. Our computations identify the following combinations of proton and neutron numbers as the most stable nuclei: Z=112, N=161,163; Z=114, N=171,178,179; and Z=124, N=194. We also investigate the alternative of heavy cluster emissions in the decay chain of 301120, instead of α decay. Our study of cluster radioactivity shows that the half-life for 10Be decay in 289114 is larger, indicating enhanced stability at Z=114, N=175. Similar calculations concerning the emission of 14C and 34Si from 301120 find the more stable combinations Z=114, N=173, and Z=106, N=161, respectively. From the same parent, 301120, the emission of a 49−51Ca cluster yielding a Z=100, N=152 daughter is the most probable. (author)

  5. A Randomized Multicentre Phase II Trial Comparing Adjuvant Therapy in Patients with Interferon Alpha-2b and 5-FU Alone or in Combination with Either External Radiation Treatment and Cisplatin (CapRI) or Radiation alone regarding Event-Free Survival – CapRI-2

    International Nuclear Information System (INIS)

    The 5-year survival of patients with resected pancreatic adenocarcinoma is still unsatisfying. The ESPAC-1 and the CONKO 001 trial proofed that adjuvant chemotherapy improves 5-year survival significantly from approximately 14% to 21%. In parallel, investigators from the Virginia Mason Clinic reported a 5-year survival rate of 55% in a phase II trial evaluating a combination of adjuvant chemotherapy, immunotherapy and external beam radiation (CapRI-scheme). Two other groups confirmed in phase II trials these results to a certain extent. However, these groups reported severe gastrointestinal toxicity (up to 93% grade 3 or 4 toxicity). In a randomized controlled phase III trial, called CapRI, 110 patients were enrolled from 2004 to 2007 in Germany and Italy to check for reproducibility. Interestingly, much less gastrointestinal toxicity was observed. However, dose-reduction due to haematological side effects had to be performed in nearly all patients. First clinical results are expected for the end of 2009. CapRI-2 is an open, controlled, prospective, randomized, multicentre phase II trial with three parallel arms. A de-escalation of the CapRI-scheme will be tested in two different modifications. Patients in study arm A will be treated as outpatients with the complete CapRI-scheme consisting of cisplatin, Interferon alpha-2b and external beam radiation and three cycles of 5-fluorouracil continuous infusion. In study arm B the first de-escalation will be realised by omitting cisplatin. Next, patients in study arm C will additionally not receive external beam radiation. A total of 135 patients with pathologically confirmed R0 or R1 resected pancreatic adenocarcinoma are planned to be enrolled. Primary endpoint is the comparison of the treatment groups with respect to six-month event-free-survival. An event is defined as grade 3 or grade 4 toxicity, objective tumour recurrence, or death. The aim of this clinical trial is to evaluate de-escalation of the CapRI-scheme. It

  6. Theoretical and experimental \\alpha decay half-lives of the heaviest odd-Z elements and general predictions

    CERN Document Server

    Zhang, H F

    2007-01-01

    Theoretical decay half-lives of the heaviest odd-Z nuclei are calculated using the experimental Q value. The barriers in the quasimolecular shape path are determined within a Generalized Liquid Drop Model (GLDM) and the WKB approximation is used. The results are compared with calculations using the Density-Dependent M3Y (DDM3Y) effective interaction and the Viola-Seaborg-Sobiczewski (VSS) formulas. The calculations provide consistent estimates for the half-lives of the decay chains of these superheavy elements. The experimental data stand between the GLDM calculations and VSS ones in the most time. Predictions are provided for the decay half-lives of other superheavy nuclei within the GLDM and VSS approaches using the recent extrapolated Q of Audi, Wapstra, and Thibault [Nucl. Phys. A729, 337 (2003)], which may be used for future experimental assignment and identification.

  7. Cytochrome P450c17 (steroid 17. cap alpha. -hydroxylase/17,20 lyase): cloning of human adrenal and testis cDNAs indicates the same gene is expressed in both tissues

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B.; Picado-Leonard, J.; Haniu, M.; Bienkowski, M.; Hall, P.F.; Shively, J.E.; Miller, W.L.

    1987-01-01

    P450c17 is the single enzyme mediating both 17..cap alpha..-hydroxylase (steroid 17..cap alpha..-monooxygenase, EC 1.14.99.9) and 17,20 lyase activities in the synthesis of steroid hormones. It has been suggested that different P450c17 isozymes mediate these activities in the adrenal gland and testis. The authors sequenced 423 of the 509 amino acids (83%) of the porcine adrenal enzyme; based on this partial sequence, a 128-fold degenerate 17-mer was synthesized and used to screen a porcine adrenal cDNA library. This yielded a 380-base cloned cDNA, which in turn was used to isolate several human adrenal cDNAs. The longest of these, lambda hac 17-2, is 1754 base pairs long and includes the full-length coding region, the complete 3'-untranslated region, and 41 bases of the 5'-untranslated region. This cDNA encodes a protein of 508 amino acids having a predicted molecular weight of 57,379.82. High-stringency screening of a human testicular cDNA library yielded a partial clone containing 1303 identical bases. RNA gel blots and nuclease S1-protection experiments confirm that the adrenal and testicular P450c17 mRNAs are indistinguishable. These data indicate that the testis possesses a P450c17 identical to that in the adrenal. The human amino acid sequence is 66.7% homologous to the corresponding regions of the porcine sequence, and the human cDNA and amino acid sequences are 80.1 and 70.3% homologous, respectively, to bovine adrenal P450c17 cDNA. Both comparisons indicate that a central region comprising amino acid residues 160-268 is hypervariable among these species of P450c17.

  8. Phase III trial of postoperative cisplatin, interferon alpha-2b, and 5-FU combined with external radiation treatment versus 5-FU alone for patients with resected pancreatic adenocarcinoma – CapRI: study protocol [ISRCTN62866759

    Directory of Open Access Journals (Sweden)

    Schmitz-Winnenthal H

    2005-04-01

    Full Text Available Abstract After surgical intervention with curative intention in specialised centres the five-year survival of patients with carcinoma of the exocrine pancreas is only 15%. The ESPAC-1 trial showed an increased five-year survival of 21% achieved with adjuvant chemotherapy. Investigators from the Virginia Mason Clinic have reported a 5-year survival rate of 55% in a phase II trial evaluating adjuvant chemotherapy, immunotherapy and external-beam radiation. Design The CapRI study is an open, controlled, prospective, randomised multi-centre phase III trial. Patients in study arm A will be treated as outpatients with 5-Fluorouracil; Cisplatin and 3 million units Interferon alpha-2b for 5 1/2 weeks combined with external beam radiation. After chemo-radiation the patients receive continuous 5-FU infusions for two more cycles. Patients in study arm B will be treated as outpatients with intravenous bolus injections of folinic acid, followed by intravenous bolus injections of 5-FU given on 5 consecutive days every 28 days for 6 cycles. A total of 110 patients with specimen-proven R0 or R1 resected pancreatic adenocarcinoma will be enrolled. An interim analysis for patient safety reasons will be done one year after start of recruitment. Evaluation of the primary endpoint will be performed two years after the last patients' enrolment. Discussion The aim of this study is to evaluate the overall survival period attained by chemo-radiotherapy including interferon alpha 2b administration with adjuvant chemotherapy. The influence of interferon alpha on the effectiveness of the patients' chemoradiation regimen, the toxicity, the disease-free interval and the quality of life are analysed. Different factors are tested in terms of their potential role as predictive markers.

  9. Death cap

    DEFF Research Database (Denmark)

    Rudbæk, Torsten R; Kofoed, Pernille Bouteloup; Bove, Jeppe;

    2014-01-01

    Death cap (Amanita phalloides) is commonly found and is one of the five most toxic fungi in Denmark. Toxicity is due to amatoxin, and poisoning is a serious medical condition, causing organ failure with potential fatal outcome. Acknowledgement and clarification of exposure, symptomatic and focused...... treatment is of primary importance. No data from randomised, controlled trials on management exists, and there is not international consensus on treatment regime. We present amatoxin-case contacts to the Danish Poison Centre from 2006-2012 and summarize current knowledge and Danish recommendations...

  10. $\\alpha_s$ review (2016)

    CERN Document Server

    d'Enterria, David

    2016-01-01

    The current world-average of the strong coupling at the Z pole mass, $\\alpha_s(m^2_{Z}) = 0.1181 \\pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\\gamma$-p collisions; and photon F$_2$ structure function in $\\gamma\\,\\gamma$ collisions. These 14 $\\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.

  11. Origin of symmetry energy in finite nuclei and density dependence of nuclear matter symmetry energy from measured alpha-decay energies

    CERN Document Server

    Dong, Jianmin; Gu, Jianzhong

    2012-01-01

    Based on the Skyrme energy density functional, the spatial distribution of the symmetry energy of a finite nucleus is derived in order to examine whether the symmetry energy of a finite nucleus originates from its interior or from its surface. It is found that the surface part of a heavy nucleus contributes dominantly to its symmetry energy compared to its inner part. The symmetry energy coefficient $a_{\\text{sym}}({A})$ is then directly extracted and the ratio of the surface symmetry coefficient to the volume symmetry coefficient $\\kappa$ is estimated. Meanwhile, with the help of experimental alpha decay energies, a macroscopic method is developed to determine the symmetry energy coefficient of heavy nuclei. The resultant $a_{\\text{sym}}({A})$ is used to analyze the density dependence of the symmetry energy coefficient of nuclear matter around the saturation density, and furthermore, the neutron skin thickness of $^{208}\\text{Pb}$ is deduced which is consistent with the pygmy dipole resonance analysis. In ad...

  12. Reactor neutron activation analysis for aluminium in the presence of phosphorus and silicon. Contributions of /sup 28/Al activities from /sup 31/P (n,. cap alpha. ) /sup 28/Al and /sup 28/Si (n,p) /sup 28/Al reactions

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, Yoshihiko (Kinki Univ., Higashi-Osaka, Osaka (Japan). Faculty of Science and Technology); Iwata, Shiro; Sasajima, Kazuhisa; Yoshimasu, Fumio; Yase, Yoshiro

    1984-01-01

    Reactor neutron activation analysis for aluminium in samples containing phosphorus and silicon was studied. The experiments were performed by using pneumatic tube of the Kyoto University Reactor (KUR). At first, the ratios of the /sup 28/Al activity produced from /sup 27/Al(n, ..gamma..) /sup 28/Al reaction by thermal neutrons to that from /sup 31/P(n, ..cap alpha..)/sup 28/Al reaction by fast neutrons, and to that from /sup 28/Si(n, p)/sup 28/Al reaction were measured by ..gamma..-ray spectrometry. With a ratio of about 5 for the thermal to fast neutron flux of KUR, the ratio of the /sup 28/Al activity from aluminium to that from phosphorus was to be 812 +- 7, and to that from silicon 282 +- 3. Secondly, the contributions of /sup 28/Al activities from phosphorus and silicon and the determination limit of aluminium were calculated for various parameters, such as fast neutron flux, thermal to fast neutron flux ratio, amounts of phosphorus and silicon, etc. Thirdly, on the basis of these results, aluminium contents in spinal cords and brains of amyotrophic lateral sclerosis, Parkinsonism-dementia complex and control cases were determined.

  13. Measurement of the parity-violating asymmetry parameter $\\alpha_b$ and the helicity amplitudes for the decay $\\Lambda_b^0\\to J/\\psi\\Lambda^0$ with the ATLAS detector

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James

    2014-01-01

    A measurement of the parity-violating decay asymmetry parameter, $\\alpha_b$, and the helicity amplitudes for the decay $\\Lambda_b^0\\to J/\\psi(\\mu^+\\mu^-) \\Lambda^0 (p\\pi^-)$ is reported. The analysis is based on 1400 $\\Lambda_b^0$ and $\\bar{\\Lambda}_b^0$ baryons selected in $4.6~\\rm{fb}^{-1}$ of proton--proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the $\\Lambda_b^0$ and $\\bar{\\Lambda}_b^0$ samples under the assumption of $CP$ conservation, the value of $\\alpha_b$ is measured to be $0.30\\pm0.16 ({\\rm stat})\\pm 0.06 ({\\rm syst})$. This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.

  14. Synthesis of tritiated 1-alpha-methadol and 1-alpha-acetylmethadol

    Energy Technology Data Exchange (ETDEWEB)

    Thang, D.C.; Nam, N.H.; Pontikis, R. (Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Fernand Widal, 75 - Paris (France)); Pichat, L. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service des Molecules Marquees)

    1982-04-01

    dl-Methadone was resolved by crystallization of its ammonium d- ..cap alpha.. -bromocamphor-..pi..-sulfonate salt to give d-methadone. The latter in ethyl acetate solution was reduced with tritium gas to 1-..cap alpha..-methadol /sup 3/H in presence of Adams platinum oxide at normal temperature and pressure. Acetylation of 1-..cap alpha..-carbinol hydrochloride by means of acetyl chloride afforded 1-..cap alpha..-acetylmethadol /sup 3/H, specific activity: 20 Ci/mMole. The positions and extent of tritium labelling were determined by /sup 3/H NMR spectroscopy.

  15. Helium precipitation in. cap alpha. -Fe

    Energy Technology Data Exchange (ETDEWEB)

    Caspers, L.M.; van Veen, A.; Ypma, M.R.; van der Kolk, G.J. (Interuniversitair Reactor Inst., Delft (Netherlands))

    1982-03-16

    The filling of a vacancy with helium atoms is studied with a programme simulating the relaxation of lattice atoms around the complex. Three filling modes are described. Helium filled V/sub 2/, V/sub 3/, and V/sub 4/ complexes are also considered and the energetics of the mutation reactions of He/sub n/V ..-->.. He/sub m>n/V/sub 2/ ..-->.. He/sub p>m/V/sub 3/ ..-->.. He/sub q>p/V/sub 4/ is studied. It is shown that these mutation reactions are more probable when the emitted interstitials remain bound to the mutation products. The He/sub n/V/sub m/I/sub p/ complexes thus formed are stable against reduction, in agreement with experiments. Also the formation of these complexes could explain why helium precipitation proceeds in a two-dimensional way as observed by TEM. The general trend found in helium desorption measurements viz. a decrease in helium binding energy until some 6 to 10 He atoms are trapped and thereafter an increase in binding energy is also found in this computer simulation study.

  16. 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-/

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-30

    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.

  17. Orthopositronium lifetime. Analytic results in O ({alpha}) and O ({alpha}{sup 3} ln {alpha})

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Kotikov, A.V.; Veretin, O.L. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-06-15

    We present the O({alpha}) and O({alpha}{sup 3}ln {alpha}) corrections to the total decay width of orthopositronium in closed analytic form, in terms of basic transcendental numbers, which can be evaluated numerically to arbitrary precision. (orig.)

  18. Study of the excited levels of 233{sup P}a by the 237{sup N}p alpha decay; Estudio de los niveles excitados en el 233{sup P}a por la desintegracion alfa del 237{sup N}p

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.; Gaeta, R.; Vano, E.; Los Arcos, J. M.

    1978-07-01

    The excited levels in 233{sup P}a following the 237{sup N}p alpha decay have been studied, by performing different experiences to complete available data and supply new information. Thus, two direct alpha spectrum measurement, one alpha-gamma bidimensional coincidence experiment, three gamma-gamma and gamma-X ray coincidences and some other measurements of the gamma spectrum, direct and coincident with alpha-particles have been made. These last experiences have allowed to obviate usual radiochemical separation methods, the 233{sup P}a radioactive descendent interferences being eliminated by means of the coincidence technic. As a result, a primary decay scheme has been elaborated, including 15 new gamma transitions and two new levels, not observed in the most recent works. (Author) 60 refs.

  19. Circular polarization measurements of Lyman-[alpha] radiation from the decay of the 2[sup 2]P[sub j] states of hydrogen excited by 54. 4 eV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Sile Nic Chormaic; Slevin, J. (Saint Patrick' s Coll., Maynooth (Ireland)); Chwirot, S. (Uniwersytet Mikolaja Kopernika, Torun (Poland). Inst. Fizyki)

    1993-01-14

    New coincidence measurements are reported for the circular polarization of Lyman-[alpha] radiation resulting from the decay of 2[sup 2]P[sub j] states excited by electron impact at an incident energy of 54.4 eV in a range of scattering angles from 5[sup o] [<=] [theta][sub e] [<=] 40[sup o]. The data were obtained using a recently developed efficient polarization analyser for this spectral line and the statistical significance of the data is much better than for previously reported measurements. The data are analysed to yield values for the coherence parameter P[sup +] and show that spin exchange interactions play a significant, if unexpected, role in the dynamic range investigated. (author).

  20. Microtubule's conformational cap

    DEFF Research Database (Denmark)

    Chretien, D.; Janosi, I.; Taveau, J.C.;

    1999-01-01

    The molecular mechanisms that allow elongation of the unstable microtubule lattice remain unclear. It is usually thought that the GDP-liganded tubulin lattice is capped by a small layer of GTP- or GDP-P(i)-liganded molecules, the so called "GTP-cap". Here, we point-out that the elastic properties...

  1. Search for CP violation in hyperon decays.

    Energy Technology Data Exchange (ETDEWEB)

    Zyla, Piotr; Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K.; Choong, W.S.; Gidal, G.; Fu, Y.; Gu, P.; Jones, T.D.; Luk, K.B.; Turko, B.; James, C.; Volk, J.; Felix, J.; Burnstein, R.A.; Chakrovorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; Solomey, N.; Torun, Y.; White, C.G.; White, S.L.; Leros, N.; Perroud, J.P.; Gustafson, H.R.; Longo, M.J.; Lopez, F.; Park H.K.; Clark, K.; Jenkins, M.; Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Lu, L.; Nelson, K.S.

    2002-10-25

    Direct CP violation in nonleptonic hyperon decays can be established by comparing the decays of hyperons and anti-hyperons. For {Xi} decay to {Lambda} {pi} followed by {Lambda} to p{pi}, the proton distribution in the rest frame of Lambda is governed by the product of the decay parameters {alpha}{sub {Xi}} {alpha}{sub {Lambda}}. The asymmetry A{sub {Xi}{Lambda}}, proportional to the difference of {alpha}{sub {Xi}}{alpha}{sub {Lambda}} of the hyperon and anti-hyperon decays, vanishes if CP is conserved. We report on an analysis of a fraction of 1997 and 1999 data collected by the Hyper CP (E871) collaboration during the fixed-target runs at Fermilab. The preliminary measurement of the asymmetry is {Alpha}{sub {Xi}{Lambda}} = [-7 {+-} 12(stat) {+-} 6.2(sys)] x 10{sup -4}, an order of magnitude better than the present limit.

  2. Synchronous Changes of the Shape of Histograms Constructed from the Results of Measurements of 90-Sr Beta-Decay and 239-Pu Alpha-Decay Observed in More than 3000 km Distant Laboratories

    Directory of Open Access Journals (Sweden)

    Filin E. Y.

    2015-07-01

    Full Text Available It was discovered many years ago that histograms constructed from the results of mea- surements of various natural processes are not random. The histogram shape was demonstrated to be determined by the diurnal rotation and circumsolar movement of the Earth and to be independent of the nature of the process considered [1-17]. The results of those works change our basic views about stochasticity of natural processes. When the time series of physical measurements, which are traditionally considered stochastic, are transformed into the series of histograms constructed for an optimally small num- ber of the results (i.e., optimally short segment of the time series, one can see regular changes in the histogram shape. The paper illustrates the main manifestations of this phenomenon by comparing the results of 90 Sr -radioactivity and 239 Pu -decay mea- surements, with the distance between the laboratories in which the data were collected being about 3000 km.

  3. Level structure of 217Rn and 221Ra investigated in the alpha-decay 225Th → 221Ra → 217Rn

    International Nuclear Information System (INIS)

    The nuclei 221Ra and 217Rn have been investigated in the α-decay chain 225Th → 221Ra → 217Rn through γ-ray and conversion-electron studies. The short-lived 225Th nuclei (T1/2=8 min) were produced in the 226Ra(α, 5n) reaction, and γ-rays and conversion electrons were measured - between the irradiation periods - in coincidence with α-particles. In 221Ra the five lowest levels are interpreted as members of a K=5/2 parity-doublet with ΔEπ=104 keV. These levels, as well as a higher-lying Kπ=3/2+ band, are consistent with an octupole deformation of 221Ra, as expected from theoretical considerations. In 217Rn only three excited levels are observed, with a favoured α-decay to a 5/2+ excited level thus establishing positive parity for the ground state of 221Ra. (orig.)

  4. Direct correlation between a negative autoregulatory response element at the cap site of the herpes simplex virus type 1 IE175 (alpha 4) promoter and a specific binding site for the IE175 (ICP4) protein.

    OpenAIRE

    Roberts, M S; Boundy, A; O'Hare, P; Pizzorno, M C; Ciufo, D M; Hayward, G S

    1988-01-01

    In transient-expression assays, the IE175 (alpha 4) promoter region of herpes simple virus is down-regulated after cotransfection with DNA encoding its own protein product (IE175 or ICP4). The inhibition by IE175 proved to be highly specific for its own promoter region and did not act on either the herpes simplex virus type 1 IE110 (alpha 0) or human cytomegalovirus major immediate-early promoters. Furthermore, the inhibition was still exhibited by IE175 effector plasmids driven by strong het...

  5. The Higgs-boson decay H\\;\\to \\;{gg} up to {\\alpha }_{s}^{5}-order under the minimal momentum space subtraction scheme

    Science.gov (United States)

    Zeng, Dai-Min; Wang, Sheng-Quan; Wu, Xing-Gang; Shen, Jian-Ming

    2016-07-01

    We study the Higgs-boson decay width {{Γ }}(H\\to {gg}) up to {α }s5 order under the minimal momentum space subtraction (mMOM) scheme. A major uncertainty of a finite-order perturbative quantum chromodymaics (pQCD) prediction is the perceived ambiguity in setting the renormalization scale. In the present paper, to achieve a precise pQCD prediction without renormalization scale uncertainty, we adopt the principle of maximum conformality (PMC) to set the renormalization scale of the process. The PMC has a solid theoretical foundation, which is based on renormalization group invariance and utilizes the renormalization group equation to fix the renormalization scale of the process. The key point of the application of the PMC is how to correctly set the {β i } terms of the process to achieve the correct α s -running behavior at each perturbative order. It is found that the ambiguities in dealing with the {β i } terms of the decay width {{Γ }}(H\\to {gg}) under the \\bar{{{MS}}} scheme can be avoided by using the physical mMOM scheme. For this purpose, for the first time we provide the PMC scale-setting formulas within the mMOM scheme up to a four-loop level. By using the PMC, it is found that a more reliable pQCD prediction on {{Γ }}(H\\to {gg}) can indeed be achieved under the mMOM scheme. As a byproduct, the convergence of the resultant pQCD series has been greatly improved due to the elimination of renormalon terms. By taking the newly measured Higgs mass, M H = 125.09 ± 0.21 ± 0.11 GeV, our PMC prediction of the decay width is, {{Γ }}(H\\to {gg}){| }{{mMOM,}{{PMC}}}=339.3+/- {1.7}-2.4+3.7 keV, in which the first error is from the Higgs mass uncertainty and the second error is the residual renormalization scale dependence by varying the initial renormalization scale {μ }r\\in [{M}H/2,4{M}H].

  6. Comparison of U.S. Environmental Protection Agency's CAP88 PC Versions 3.0 and 4.0.

    Science.gov (United States)

    Jannik, Tim; Farfan, Eduardo B; Dixon, Ken; Newton, Joseph; Sailors, Christopher; Johnson, Levi; Moore, Kelsey; Stahman, Richard

    2015-08-01

    The Savannah River National Laboratory (SRNL) with the assistance of Georgia Regents University, completed a comparison of the U.S. Environmental Protection Agency's (U.S. EPA) environmental dosimetry code CAP88 PC V3.0 with the recently developed V4.0. CAP88 is a set of computer programs and databases used for estimation of dose and risk from radionuclide emissions to air. At the U.S. Department of Energy's Savannah River Site, CAP88 is used by SRNL for determining compliance with U.S. EPA's National Emission Standards for Hazardous Air Pollutants (40 CFR 61, Subpart H) regulations. Using standardized input parameters, individual runs were conducted for each radionuclide within its corresponding database. Some radioactive decay constants, human usage parameters, and dose coefficients changed between the two versions, directly causing a proportional change in the total effective dose. A detailed summary for select radionuclides of concern at the Savannah River Site (60Co, 137Cs, 3H, 129I, 239Pu, and 90Sr) is provided. In general, the total effective doses will decrease for alpha/beta emitters because of reduced inhalation and ingestion rates in V4.0. However, for gamma emitters, such as 60Co and 137Cs, the total effective doses will increase because of changes U.S. EPA made in the external ground shine calculations.

  7. A Phrygian Cap

    Directory of Open Access Journals (Sweden)

    Marie-Janne S. van Kamp

    2013-08-01

    Full Text Available A Phrygian cap is a congenital anomaly of the gallbladder with an incidence of 4%. It can simulate a mass in the liver during hepatobiliary imaging and is sometimes mistaken for pathology. A Phrygian cap, however, has no pathological significance and normally causes no symptoms. A case will be presented where a Phrygian cap was found by coincidence during surgery. The patient was operated for colon cancer with liver metastasis in segment V. He underwent a simultaneous right hemicolectomy and wedge resection of the liver lesion. During perioperative inspection, a gallbladder with a folded fundus was seen. This deformity was, in retrospective, detected on the preoperative MRI scan. The patient underwent cholecystectomy to make the wedge resection easier to perform. Otherwise, cholecystectomy for a Phrygian cap is only indicated in case of symptoms. Radiographic imaging can be helpful in narrowing the differential diagnosis. To our knowledge, there is no recent literature about the Phrygian cap and its imaging aspects. Nowadays, multiphase MRI, or multiphase CT in case of MRI contraindication, are the first choices of hepatobiliary imaging.

  8. 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-

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. Successful treatment of cap polyposis with infliximab.

    Science.gov (United States)

    Bookman, Ian D; Redston, Mark S; Greenberg, Gordon R

    2004-06-01

    Cap polyposis is a disorder characterized by bloody diarrhea with rectosigmoid polyps covered by a cap of fibropurulent exudate. The pathogenesis is unknown, but histological features suggest that mucosal prolapse may play a role. Drug therapies are usually unsuccessful, and treatment requires sigmoid resection or, if the disease recurs after initial surgical resection, panproctocolectomy. We report the case of a 36-year-old woman with characteristic clinical, endoscopic, and histological features of cap polyposis. Investigations included normal anorectal manometry and defecography, without evidence of prolapse. The patient's disease was unresponsive to treatment with mesalamine, antibiotics, lidocaine enemas, and corticosteroids. One infusion of infliximab 5 mg/kg provided dramatic symptomatic improvement but minimal endoscopic or histological change. After 4 infliximab infusions at 8-week intervals, endoscopy of the rectum and sigmoid colon was normal, and biopsies showed complete histological resolution of the inflammatory process. Well-being with normal endoscopy and histology has been maintained at 38 months, without further treatment. It was concluded that infliximab is effective therapy for cap polyposis and avoids the requirement for surgery. No clinical evidence was obtained to support mucosal prolapse as a causative factor, but the response to infliximab suggests a role for tumor necrosis factor-alpha in the pathogenesis of this disorder. PMID:15188181

  10. The strong coupling from tau decays without prejudice

    CERN Document Server

    Boito, Diogo; Jamin, Matthias; Mahdavi, Andisheh; Maltman, Kim; Osborne, James; Peris, Santiago

    2012-01-01

    We review our recent determination of the strong coupling \\alpha_s from the OPAL data for non-strange hadronic tau decays. We find that \\alpha_s(m^2_\\tau) =0.325+-0.018 using fixed-order perturbation theory, and \\alpha_s(m^2_\\tau)=0.347+-0.025 using contour-improved perturbation theory. At present, these values supersede any earlier determinations of the strong coupling from hadronic tau decays, including those from ALEPH data.

  11. Polarization in heavy quark decays

    Energy Technology Data Exchange (ETDEWEB)

    Alimujiang, K.

    2006-07-01

    In this thesis I concentrate on the angular correlations in top quark decays and their next.to.leading order (NLO) QCD corrections. I also discuss the leading.order (LO) angular correlations in unpolarized and polarized hyperon decays. In the first part of the thesis I calculate the angular correlation between the top quark spin and the momentum of decay products in the rest frame decay of a polarized top quark into a charged Higgs boson and a bottom quark in Two-Higgs-Doublet-Models: t({up_arrow}) {yields} b + H{sup +}. I provide closed form formulae for the O({alpha}{sub s}) radiative corrections to the unpolarized and the polar correlation functions for m{sub b}{ne}0 and m{sub b}=0. In the second part I concentrate on the semileptonic rest frame decay of a polarized top quark into a bottom quark and a lepton pair: t({up_arrow}){yields}X{sub b}+l{sup +}+{nu}{sub l}. I present closed form expressions for the O({alpha}{sub s}) radiative corrections to the unpolarized part and the polar and azimuthal correlations for m{sub b}{ne}0 and m{sub b}=0. In the last part I turn to the angular distribution in semileptonic hyperon decays. Using the helicity method I derive complete formulas for the leading order joint angular decay distributions occurring in semileptonic hyperon decays including lepton mass and polarization effects. (orig.)

  12. Investigation of probable decays in rhenium isotopes

    International Nuclear Information System (INIS)

    Making use of effective liquid drop model (ELDM), the feasibility of proton and alpha decays and various cluster decays is analysed theoretically. For different neutron-rich and neutron-deficient isotopes of Rhenium in the mass range 150 < A < 200, the half-lives of proton and alpha decays and probable cluster decays are calculated considering the barrier potential as the effective liquid drop one which is the sum of Coulomb, surface and centrifugal potentials. The calculated half-lives for proton decay from various Rhenium isotopes are then compared with the universal decay law (UDL) model to assess the efficiency of the present formalism. Geiger-Nuttal plots of the probable decays are analysed and their respective slopes and intercepts are evaluated

  13. Recoil-alpha-fission and recoil-alpha-alpha-fission events observed in the reaction Ca-48 + Am-243

    CERN Document Server

    Forsberg, U; Andersson, L -L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Golubev, P; Gregorich, K E; Gross, C J; Herzberg, R -D; Hessberger, F P; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Sarmiento, L G; Schädel, M; Yakushev, A; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Dobaczewski, J; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nazarewicz, W; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Shi, Y; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2015-01-01

    Products of the fusion-evaporation reaction Ca-48 + Am-243 were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum f\\"ur Schwerionenforschung. Amongst the detected thirty correlated alpha-decay chains associated with the production of element Z=115, two recoil-alpha-fission and five recoil-alpha-alpha-fission events were observed. The latter are similar to four such events reported from experiments performed at the Dubna gas-filled separator. Contrary to their interpretation, we propose an alternative view, namely to assign eight of these eleven decay chains of recoil-alpha(-alpha)-fission type to start from the 3n-evaporation channel 115-288. The other three decay chains remain viable candidates for the 2n-evaporation channel 115-289.

  14. Modes of decay in neutron-rich nuclei

    CERN Document Server

    Kumar, B; Singh, S K; Lahiri, C; Patra, S K

    2016-01-01

    We calculate the ground, first intrinsic excited states and density distribution for neutron-rich thorium and uranium isotopes, within the framework of relativistic mean field(RMF) approach using axially deformed basis. The total nucleon densities are calculated, from which the cluster-structures inside the parent nuclei are determined. The possible modes of decay, like {\\alpha}-decay and \\b{eta} -decay are analyzed. We find the neutron-rich isotopes are stable against {\\alpha}-decay, however they are very much unstable against \\b{eta} -decay. The life time of these nuclei predicted to be tens of second against \\b{eta} -decay.

  15. Identification of Cytoplasmic Capping Targets Reveals a Role for Cap Homeostasis in Translation and mRNA Stability

    Directory of Open Access Journals (Sweden)

    Chandrama Mukherjee

    2012-09-01

    Full Text Available The notion that decapping leads irreversibly to messenger RNA (mRNA decay was contradicted by the identification of capped transcripts missing portions of their 5′ ends and a cytoplasmic complex that can restore the cap on uncapped mRNAs. In this study, we used accumulation of uncapped transcripts in cells inhibited for cytoplasmic capping to identify the targets of this pathway. Inhibition of cytoplasmic capping results in the destabilization of some transcripts and the redistribution of others from polysomes to nontranslating messenger ribonucleoproteins, where they accumulate in an uncapped state. Only a portion of the mRNA transcriptome is affected by cytoplasmic capping, and its targets encode proteins involved in nucleotide binding, RNA and protein localization, and the mitotic cell cycle. The 3′ untranslated regions of recapping targets are enriched for AU-rich elements and microRNA binding sites, both of which function in cap-dependent mRNA silencing. These findings identify a cyclical process of decapping and recapping that we term cap homeostasis.

  16. Coefficient Alpha

    OpenAIRE

    Panayiotis Panayides

    2013-01-01

    Heavy reliance on Cronbach’s alpha has been standard practice in many validation studies. However, there seem to be two misconceptions about the interpretation of alpha. First, alpha is mistakenly considered as an indication of unidimensionality and second, that the higher the value of alpha the better. The aim of this study is to clarify these misconceptions with the use of real data from the educational setting. Results showed that high alpha values can be obtained in multidimensional scale...

  17. Performance of blasting caps

    Science.gov (United States)

    Bement, Laurence J. (Inventor); Schimmel, Morry L. (Inventor); Perry, Ronnie B. (Inventor)

    1993-01-01

    Common blasting caps are made from an aluminum shell in the form of a tube which is closed at both ends. One end, which is called the output end, terminates in a principal side or face, and contains a detonating agent which communicates with a means for igniting the detonating agent. The improvement of the present invention is a flat, steel foil bonded to the face in a position which is aligned perpendicularly to the longitudinal axis of the tube.

  18. Capping the Mortgage Interest Deduction

    OpenAIRE

    Anderson, John E.; Clemens, Jeffrey; Hanson, Andrew

    2007-01-01

    In this paper we examine the economic implications of several policy options for capping the mortgage interest deduction (MID). We extend the standard user–cost model of owner–occupied housing to include a cap on the mortgage size receiving tax–favored status. Our user–cost estimates for taxpayers with mortgages above the current–law cap are 4.41 percent higher than estimates from a model without the cap. We simulate the share of mortgage dollars that would be subject to three alternative cap...

  19. Quantum time scales in alpha tunneling

    CERN Document Server

    Kelkar, N G; Nowakowski, M

    2008-01-01

    The theoretical treatment of alpha decay by Gamow is revisited by investigating the quantum time scales in tunneling. The time spent by an alpha particle in front of the barrier and traversing it before escape is evaluated using microscopic alpha nucleus potentials. The half-life of a nucleus is shown to correspond to the time spent by the alpha knocking in front of the barrier. Calculations for medium and super heavy nuclei show that from a multitude of available tunneling time definitions, the transmission dwell time gives the bulk of the lifetime of the decaying state, in most cases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

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

  1. Validation of Geant4-based Radioactive Decay Simulation

    OpenAIRE

    Hauf, Steffen; Kuster, Markus; Batič, Matej; Bell, Zane W.; Dieter H.H. Hoffmann; Lang, Philipp M.; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    Radioactive decays are of concern in a wide variety of applications using Monte-Carlo simulations. In order to properly estimate the quality of such simulations, knowledge of the accuracy of the decay simulation is required. We present a validation of the original Geant4 Radioactive Decay Module, which uses a per-decay sampling approach, and of an extended package for Geant4-based simulation of radioactive decays, which, in addition to being able to use a refactored per-decay sampling, is cap...

  2. Giant-enhancement of extraordinary optical transmission through nanohole arrays blocked by plasmonic gold mushroom caps

    Science.gov (United States)

    Zhang, Qing; Hu, Pidong; Liu, Chengpu

    2015-01-01

    An improved plasmonic hole array nanostructure model with the holes blocked by gold mushroom caps is proposed and it can realize a giant transmission with efficiency up to 65%, 182% larger than the unblocked nanohole array, due to the strong coupling between caps and holes, which plays the role of a cavity antenna. Moreover, the numerical investigation confirms that it provides more consistency with the practical experimental situations, than the nanodisk model instead. As expected, the light transmission sensitively depends on the geometric parameters of this new nanostructure; as the cap-hole's gap or cap's diameter vary, there always exists an optimal transmission efficiency. More interesting is that the corresponding optimal wavelength decreases with the gap's increment or the diameter's decrement, particularly in an exponential decaying way, and the decay rate is obviously influenced by the cap's parameters.

  3. $b$-hadrons decays at ATLAS

    CERN Document Server

    Turchikhin, Semen; The ATLAS collaboration

    2016-01-01

    Recent results on $\\Lambda^0_b$ baryon and $B_c^+$ meson decay studies from the ATLAS experiment at the LHC are presented. These include measurement of the parity-violating asymmetry parameter $\\alpha_b$ and the helicity amplitudes for the $\\Lambda^0_b\\to J/\\psi\\Lambda^0_b$ decay, first observation of the $\\Lambda^0_b\\to\\psi(2S)\\Lambda^0_b$ decay and measurement of its rate relative to the $\\Lambda^0_b\\to J/\\psi\\Lambda^0$ decay, and study of the $B_c^+\\to J/\\psi D_s^{(*)+}$ decay properties.

  4. Saltstone Clean Cap Formulation

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C

    2005-04-22

    The current operation strategy for using Saltstone Vault 4 to receive 0.2 Ci/gallon salt solution waste involves pouring a clean grout layer over the radioactive grout prior to initiating pour into another cell. This will minimize the radiating surface area and reduce the dose rate at the vault and surrounding area. The Clean Cap will be used to shield about four feet of Saltstone poured into a Z-Area vault cell prior to moving to another cell. The minimum thickness of the Clean Cap layer will be determined by the cesium concentration and resulting dose levels and it is expected to be about one foot thick based on current calculations for 0.1 Ci Saltstone that is produced in the Saltstone process by stabilization of 0.2 Ci salt solution. This report documents experiments performed to identify a formulation for the Clean Cap. Thermal transient calculations, adiabatic temperature rise measurements, pour height, time between pour calculations and shielding calculations were beyond the scope and time limitations of this study. However, data required for shielding calculations (composition and specific gravity) are provided for shielding calculations. The approach used to design a Clean Cap formulation was to produce a slurry from the reference premix (10/45/45 weight percent cement/slag/fly ash) and domestic water that resembled as closely as possible the properties of the Saltstone slurry. In addition, options were investigated that may offer advantages such as less bleed water and less heat generation. The options with less bleed water required addition of dispersants. The options with lower heat contained more fly ash and less slag. A mix containing 10/45/45 weight percent cement/slag/fly ash with a water to premix ratio of 0.60 is recommended for the Clean Cap. Although this mix may generate more than 3 volume percent standing water (bleed water), it has rheological, mixing and flow properties that are similar to previously processed Saltstone. The recommended

  5. Tau decays

    International Nuclear Information System (INIS)

    The most recent experimental results of τ physics are reviewed. The covered topics include precision measurements of semihadronic τ decay and their impact on tau branching ratio budget, the current status of the tau consistency test, a determination of Michel parameters and τ neutrino helicity, and upper limits on lepton-number violating τ decays. (orig.)

  6. Decay properties of heavier nuclei and mass formula

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Masahiro [Ministry of Education, Science and Culture, Tokyo (Japan)

    2000-03-01

    The stabilities of heavy nuclei, including super-heavy elements, are governed by alpha decay and fission. Some exotic types of decay, such as heavy cluster decay, which does not occur so frequently as to govern stability, have been also reported. The half-time estimations of various types of decay are reviewed. And the possibility of decay, mainly in case of heavy cluster decay, is discussed with Q-value obtained from mass formulae as well. Some topics concerning other types of exotic decay are presented. Recent trends in the research on mass formula are reviewed from the historical point of view, to get perspectives of future development. (Yamamoto, A.)

  7. The 2009 Wolrd Average of $\\alpha_s (M_Z)$

    CERN Document Server

    Bethke, Siegfried

    2009-01-01

    Measurements of $\\alpha_s$, the coupling strength of the Strong Interaction between quarks and gluons, are summarised and an updated value of the world average of $\\alpha_s (M_Z)$ is derived. Building up on previous reviews, special emphasis is laid on the most recent determinations of $\\alpha_s$. These are obtained from $\\tau$-decays, from global fits of electroweak precision data and from measurements of the proton structure function $\\F_2$, which are based on perturbative QCD calculations up to $O(\\alpha_s^4)$; from hadronic event shapes and jet production in $\\epem$ annihilation, based on $O(\\alpha_s^3) $ QCD; from jet production in deep inelastic scattering and from $\\Upsilon$ decays, based on $O(\\alpha_s^2) $ QCD; and from heavy quarkonia based on unquenched QCD lattice calculations. Applying pragmatic methods to deal with possibly underestimated errors and/or unknown correlations, the world average value of $\\alpha_s (M_Z)$ results in $\\alpha_s (M_Z) = 0.1184 \\pm 0.0007$. The measured values of $\\alpha...

  8. Planar track model and the prediction of alpha-recoil aging in radwaste materials

    Energy Technology Data Exchange (ETDEWEB)

    Borg, J.; Dran, J.C.; Langevin, Y.; Maurette, M.; Petit, J.C.; Vassent, B. (Paris-11 Univ., 91 - Orsay (France). Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse)

    1982-10-01

    High fluences of low energy heavy ions generate very thin layers of radiation-damaged material on the surface of solid-state track detectors such as glasses and silicate minerals. For glasses, such layers undergo above a critical dose complex modifications in their chemical reactivity which strongly depend on the particular glass-leachant system. We have explained this striking threshold effect by the formation of a particular structural state on both crystalline and amorphous insulators, generated by the accumulation of individual damaged islands produced by the incident ions. We first recall our experimental technique that is based on an implantation of lead ions. Then we report on new experimental results on the ion-induced etchability of two very different insulating materials, muscovite mica and soda-lime glass which are conveniently described by a refined version of our planar track model. Finally, by assimilating such lead ions to recoil nuclei emitted during the ..cap alpha..-decay of actinide elements incorporated in radioactive waste storage materials (radwaste materials) we tentatively apply this new concept of planar track to the important problem of radiation stability of radwaste materials exposed to the internal irradiation with ..cap alpha..-recoils and subjected to corrosion by ground waters.

  9. Novel Multipin Electrode Cap System for Dry Electroencephalography.

    Science.gov (United States)

    Fiedler, P; Pedrosa, P; Griebel, S; Fonseca, C; Vaz, F; Supriyanto, E; Zanow, F; Haueisen, J

    2015-09-01

    Current usage of electroencephalography (EEG) is limited to laboratory environments. Self-application of a multichannel wet EEG caps is practically impossible, since the application of state-of-the-art wet EEG sensors requires trained laboratory staff. We propose a novel EEG cap system with multipin dry electrodes overcoming this problem. We describe the design of a novel 24-pin dry electrode made from polyurethane and coated with Ag/AgCl. A textile cap system holds 97 of these dry electrodes. An EEG study with 20 volunteers compares the 97-channel dry EEG cap with a conventional 128-channel wet EEG cap for resting state EEG, alpha activity, eye blink artifacts and checkerboard pattern reversal visual evoked potentials. All volunteers report a good cap fit and good wearing comfort. Average impedances are below 150 kΩ for 92 out of 97 dry electrodes, enabling recording with standard EEG amplifiers. No significant differences are observed between wet and dry power spectral densities for all EEG bands. No significant differences are observed between the wet and dry global field power time courses of visual evoked potentials. The 2D interpolated topographic maps show significant differences of 3.52 and 0.44% of the map areas for the N75 and N145 VEP components, respectively. For the P100 component, no significant differences are observed. Dry multipin electrodes integrated in a textile EEG cap overcome the principle limitations of wet electrodes, allow rapid application of EEG multichannel caps by non-trained persons, and thus enable new fields of application for multichannel EEG acquisition.

  10. Proton Decay

    OpenAIRE

    Raby, Stuart

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  11. Alpha Schottky junction energy source

    Science.gov (United States)

    Litz, Marc S.; Fan, Zhaoyang; Carroll, James J.; Bayne, Stephen

    2012-06-01

    Isotope batteries offer solutions for long-lived low-power sensor requirements. Alpha emitting isotopes have energy per decay 103 times that of beta emitters. Alpha particles are absorbed within 20 μm of most materials reducing shielding mitigation. However, damage to materials from the alphas limits their practical use. A Schottky Barrier Diode (SBD) geometry is considered with an alpha emitting contact-layer on a diamond-like crystal semiconductor region. The radiation tolerance of diamond, the safety of alpha particles, combined with the internal field of the SBD is expected to generate current useful for low-power electronic devices over decades. Device design parameters and calculations of the expected current are described.

  12. ATLAS end-cap detector

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Three scientists from the Institute of Nuclear Phyiscs at Novossibirsk with one of the end-caps of the ATLAS detector. The end-caps will be used to detect particles produced in the proton-proton collisions at the heart of the ATLAS experiment that are travelling close to the axis of the two beams.

  13. B decays

    CERN Document Server

    Stone, Sheldon

    1992-01-01

    The study of b quarks has now reached a stage where it is useful to review what has been learned so far and also to look at the implications of future studies. The most important observations thus far - measurement of the "B" lifetime, B 0 - B 0 mixing, and the observation of b? u transitions, as well as more mundane results on hadronic and semileptonic transitions - are described in detail by experimentalists who have been closely involved with the measurements. Theoretical progress in understanding b quark decays, including the mechanisms of hadronic and semileptonic decays, are described. S

  14. Buffett's Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting...

  15. Decay Probability Ratio of Pentaquark Theta^+ State

    CERN Document Server

    Chen, X; Ma, B Q; Chen, Xun; Mao, Yajun; Ma, Bo-Qiang

    2003-01-01

    The pentaquark state of $\\Theta^{+}(uudd\\bar{s})$ has been observed to decay with two decay modes: $\\Theta^+\\to n K^+$ and $\\Theta^+ \\to p K^0$. The decay probability ratio of the two decay modes is studied with general symmetry consideration of isospin, spin, and parity. We arrive at a result of the ratio $\\frac{\\Gamma(\\Theta^+\\to nK^+)}{\\Gamma(\\Theta^+\\to pK^0)} =\\frac{(\\alpha-\\beta)^2}{(\\alpha+\\beta)^2}(\\frac{k_1}{k_2})^{2L+1}$, which is valid for the $\\Theta^+$ state to be a pure isoscalar or isovector state, or an isotensor state with mixture of isoscalar and isovector components with coefficients $\\alpha$ and $\\beta$. The dependence on spin and parity of the pentaquark $\\Theta^+$ state is found to be small due to small difference between the center of mass decay momenta $k_1$ and $k_2$ of the two decay modes. Future experimental results about the decay probability ratio may provide information about the isospin configuration of the pentaquark $\\Theta^+$ state.

  16. ATLAS - End-Cap calorimeter

    CERN Multimedia

    2006-01-01

    The End-cap calorimeter was moved with the help of the rails and this calorimeter will measure the energy of particles close to the beam axis when protons collide. Cooling is important for maximum detector efficiency.

  17. Researchers dodge UK migration cap

    Science.gov (United States)

    Dacey, James

    2011-03-01

    Research scientists are among those to be prioritized under the UK government's new immigration rules that will impose an annual cap on the number of work visas issued to those from outside the European Union (EU).

  18. Genetics Home Reference: cap myopathy

    Science.gov (United States)

    ... or a spine that curves to the side ( scoliosis ). The name cap myopathy comes from characteristic abnormal ... health conditions: Diagnostic Tests Drug Therapy Surgery and Rehabilitation Genetic Counseling Palliative Care Related Information How are ...

  19. Perturbative expansion of tau hadronic spectral function moments and alpha_s extractions

    CERN Document Server

    Beneke, Martin; Jamin, Matthias

    2012-01-01

    Various moments of the hadronic spectral functions have been employed in the determination of the strong coupling alpha_s from tau decays. In this work we study the behaviour of their perturbative series under different assumptions for the large-order behaviour of the Adler function, extending previous work on the tau hadronic width. We find that the moments can be divided into a small number of classes, whose characteristics depend only on generic features of the moment weight function and Adler function series. Some moments that are commonly employed in alpha_s analyses from tau decays should be avoided because of their perturbative instability. This conclusion is corroborated by a simplified alpha_s extraction from individual moments. Furthermore, under reasonable assumptions for the higher-order behaviour of the perturbative series, fixed-order perturbation theory (FOPT) provides the preferred framework for the renormalization group improvement of all moments that show good perturbative behaviour. Finally...

  20. Alpha fetoprotein

    Science.gov (United States)

    Fetal alpha globulin; AFP ... Greater than normal levels of AFP may be due to: Cancer in testes , ovaries, biliary (liver secretion) tract, stomach, or pancreas Cirrhosis of the liver Liver cancer ...

  1. Decay scheme of the U235

    International Nuclear Information System (INIS)

    A study of the Th231 excited levels from the alpha decay of the U235, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U235, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs

  2. Azimuthal correlation between the $(\\vec{p}_l,\\vec{p}_{X_b})$ and $(\\vec{p}_l,\\vec{P}_t)$ planes in the semileptonic rest frame decay of a polarized top quark: An $O(\\alpha_s)$ effect

    CERN Document Server

    Groote, S; Kadeer, A; Körner, J G

    2006-01-01

    The azimuthal correlation between the planes formed by the vectors $(\\vec{p}_l,\\vec{p}_{X_b})$ and $(\\vec{p}_l,\\vec{P}_t)$ in the semileptonic rest frame decay of a polarized top quark $t(\\uparrow) \\to X_b + l^+ + \

  3. JENDL FP decay data file 2000

    Energy Technology Data Exchange (ETDEWEB)

    Katakura, Jun-ichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshida, Tadashi [Musashi Inst. of Tech., Tokyo (Japan); Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Nagakute, Aichi (Japan); Tachibana, Takahiro [Waseda Univ., Tokyo (Japan)

    2001-07-01

    A decay data file of fission product (FP) nuclides has been developed for the use in nuclear technology field as one of special purpose files of JENDL (Japanese Evaluated Nuclear Data Library) in the format of ENDF/B and it is called JENDL FP Decay Data File 2000. The file includes the decay data for 1229 fission product nuclides: 142 stable and 1087 unstable nuclides. The data included for a nuclide are decay modes, their Q values and branching ratios, average decay energy values of beta-rays, gamma-rays and alpha-particles and their spectral data. The primary source of the decay data is ENSDF (Evaluated Nuclear Structure Data File), which is the internationally recognized data file of nuclear structure properties. The data in ENSDF, however, cover only measured ones. The data of the short-lived nuclides needed for the application fields such as decay heat prediction are often incomplete or not measured because of their short half-lives. For such nuclides a theoretical model calculation is applied to derive the needed data such as average decay energies and spectral data. The data in JENDL FP Decay Data File 2000 have been tested by summation calculation comparing its results with measured data of decay heat values and aggregate fission product spectra of various fissioning nuclei. The comparison showed good agreement between the calculated results and the measured values. (author)

  4. Creation of polar cap patches

    Science.gov (United States)

    Hosokawa, K.; Taguchi, S.; Ogawa, Y.

    2014-12-01

    Polar cap patches, which are islands of enhanced plasma density drifting anti-sunward, are one of the outstanding phenomena in the polar cap F region ionosphere. In the last decade, data from all-sky airglow imagers have been extensively used for better understanding the propagation of patches in the central polar cap region. But still, it has been rather difficult to capture the birth of patches in their generation region near the dayside cusp, because, in most places, the dayside part of the polar cap ionosphere is sunlit even in winter. In Longyearbyen (78.1N, 15.5E), Norway, however, optical observations are possible near the dayside cusp region in a limited period around the winter solstice. This enables us to directly image how polar cap patches are born in the cusp. In this paper, we present a few intervals of daytime optical observations, during which polar cap patches were generated within the field-of-view of an all-sky imager in Longyearbyen. During all the intervals studied here, we identified several signatures of poleward moving auroral forms (PMAF) in the equatorward half of the field-of-view, which are known as ionospheric manifestations of dayside reconnection. Interestingly, patches were directly produced from such poleward moving auroral signatures and propagated poleward along the anti-sunward convection near the cusp. In the literature, Lorentzen et al. (2012) first reported such a direct production of patches from PMAFs. During the current observations, however, we succeeded in tracking the propagation of patches until they reached the poleward edge of the field-of-view of the imager. This confirms that the faint airglow structures produced from PMAFs were actually transported for a long distance towards the central polar cap area; thus, polar cap patches were produced. From this set of observations, we suggest that polar cap patches during moderately disturbed conditions (i.e, non-storm time conditions) can be directly produced by the

  5. Crystal structure of Bacillus anthracis transpeptidase enzyme CapD.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R.; Richter, S.; Zhang, R.; Anderson, V. J.; Missiakas, D.; Joachimiak, A.; Biosciences Division; Univ. of Chicago

    2009-09-04

    Bacillus anthracis elaborates a poly-{gamma}-d-glutamic acid capsule that protects bacilli from phagocytic killing during infection. The enzyme CapD generates amide bonds with peptidoglycan cross-bridges to anchor capsular material within the cell wall envelope of B. anthracis. The capsular biosynthetic pathway is essential for virulence during anthrax infections and can be targeted for anti-infective inhibition with small molecules. Here, we present the crystal structures of the {gamma}-glutamyltranspeptidase CapD with and without {alpha}-l-Glu-l-Glu dipeptide, a non-hydrolyzable analog of poly-{gamma}-d-glutamic acid, in the active site. Purified CapD displays transpeptidation activity in vitro, and its structure reveals an active site broadly accessible for poly-{gamma}-glutamate binding and processing. Using structural and biochemical information, we derive a mechanistic model for CapD catalysis whereby Pro{sup 427}, Gly{sup 428}, and Gly{sup 429} activate the catalytic residue of the enzyme, Thr{sup 352}, and stabilize an oxyanion hole via main chain amide hydrogen bonds.

  6. The North Zealand CAP Monitor

    DEFF Research Database (Denmark)

    Nielsen, Minna; Ravn, Pernille; Notander Clausen, Lise;

    2016-01-01

    nurses and two senior doctors. Direct observations of the clinical processes revealed problems of coordination, complex disease trajectories that did not fit with the pneumonia pathway, unclear guidelines and variation in their interpretation. Intervention We designed a measurement system to monitor...... patients with CAP and effects of interventions to improve the quality of their care. Based on current literature we defined and tested a set of indicators and designed an audit form, a database and a dashboard for presenting the results. Two nurses monthly audited randomly selected files of patients...... steps of the pneumonia pathway. Lessons learnt Quality of care for CAP was worse than expected. Defining and agreeing upon a set of indicators was difficult and time consuming but useful to improve our understanding of how care for CAP was in routine clinical practice. Several indicators we initially...

  7. Resonances in alpha-nuclei interaction

    Energy Technology Data Exchange (ETDEWEB)

    Karpeshin, F F [Fock Institute of Physics, St Petersburg State University, RU-198504 St Petersburg (Russian Federation); La Rana, G [Instituto Nazionale di Fisica Nucleare and Dipartimento di Scienze Fisiche dell' Universita di Napoli, Monte S. Angelo, via Cintia, 80126 Naples (Italy); Vardaci, Emanuele [Instituto Nazionale di Fisica Nucleare and Dipartimento di Scienze Fisiche dell' Universita di Napoli, Monte S. Angelo, via Cintia, 80126 Naples (Italy); Brondi, Augusto [Instituto Nazionale di Fisica Nucleare and Dipartimento di Scienze Fisiche dell' Universita di Napoli, Monte S. Angelo, via Cintia, 80126 Naples (Italy); Moro, Renata [Instituto Nazionale di Fisica Nucleare and Dipartimento di Scienze Fisiche dell' Universita di Napoli, Monte S. Angelo, via Cintia, 80126 Naples (Italy); Abramovich, S N [Russian Federal Nuclear Centre VNIIEF, RU-607190 Sarov, Nizhny Novgorod Region (Russian Federation); Serov, V I [Russian Federal Nuclear Centre VNIIEF, RU-607190 Sarov, Nizhny Novgorod Region (Russian Federation)

    2007-03-15

    Tunnelling of {alpha} particles through the Coulomb barrier is considered. The main attention is given to the effect of sharp peaks arising in the case of coincidence of the {alpha} energy with that of a quasistaionary state within the barrier. The question of the {alpha}-nucleus potential is discussed in this light. The method is applied to the {alpha} decay of a compound nucleus of {sup 135}Pr. The appearance of the peaks in the spectrum of emitted particles is predicted. They can give rise to 'anomalous' properties of some neutron resonances. The peaks can also be observed in the incoming {alpha}-nucleus channel. Observation of the peaks would give unique information about the {alpha}-nucleus potential.

  8. Workshop on Precision Measurements of alphas

    CERN Document Server

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

    2011-01-01

    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.

  9. SK Model and decay properties of 119299X

    International Nuclear Information System (INIS)

    In this work, using SK Model we try to study the alpha decay properties of the yet to be formed nucleus 119299X, the formation of which has been proposed by Zagrebaev et. al. The decay properties of other known odd and even superheavy nuclei have already been analyzed with this model

  10. From Blogs to Bottle Caps

    Science.gov (United States)

    Edinger, Ted

    2012-01-01

    There is a wonderful community of art educators connecting a once-isolated profession through blogging. Art educators around the world are sharing ideas and communicating with their peers through this amazing resource. In this article, the author describes the bottle cap mural at Tulip Grove Elementary School which was inspired by this exchange of…

  11. Determination of the Dalitz-plot parameter {alpha} for the decay {eta}{yields}3{pi}{sup 0} with the Crystal Ball at MAMI; Bestimmung des Dalitz-Plot-Parameters {alpha} fuer den Zerfall {eta} {yields} 3{pi}{sup 0} mit dem Crystal Ball am MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Unverzagt, Marc

    2008-05-26

    In order to determine the Dalitz-plot parameter {alpha} experiments were evaluated, Which were performed with the Crystal Ball/TAPS facility at the accelerator MAMI of the Institute for Nuclear Physics at the Johannes Gutenberg University in Mainz in the years 2004 and 2005. {eta} mesons wer produced via the reaction {gamma}p{yields}{eta}p. From four different analyses the following four in this thesis determined Dalitz-plot parameters with the given statistics resulted: {eta} without proton: {alpha}=-0.0314{+-}0.0013{sub -0.0014}{sup +0.0017} (1.1.10{sup 6} events), {eta} with proton: {alpha}=-0.0338{+-}0.0020{sub -0.0022}{sup +0.0019} (4.2.10{sup 5} events), {delta}{sup +} magnetic dipole moment without proton: {alpha}=-0.0277{+-}0.0013{sub -0.0019}{sup +0.0014} (7.1.10{sup 5} events), {delta}{sup +} magnetic dipole moment with proton: {alpha}=-0.0272{+-}0.0019{sub -0.0043}{sup +0.0022} (3.1.10{sup 5} events).

  12. Rescattering effects in eta --> 3pi decays

    CERN Document Server

    Schneider, Sebastian P; Ditsche, Christoph

    2010-01-01

    The isospin-breaking decay eta --> 3pi is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that respect, in particular the slope parameter alpha of the neutral decay channel causes some concern, since the one-loop prediction from chiral perturbation theory misses the experimental value substantially. We use the modified non-relativistic effective field-theory, a dedicated framework to analyze final-state interactions beyond one loop including isospin-breaking corrections, to extract charged and neutral Dalitz plot parameters. Matching to chiral perturbation theory at next-to-leading order, we find alpha = -0.025 +- 0.005, in marginal agreement with experimental findings. We derive a relation between charged and neutral decay parameters that points towards a significant tension between the most recent KLOE measurements of these observables.

  13. Afterglow-reabsorbed H/sub alpha/ line delay effect in an expanding laser plasma

    Energy Technology Data Exchange (ETDEWEB)

    Derzhiev, V.I.; Zhidkov, A.G.; Maiorov, S.A.; Yakovlenko, S.I.

    1987-11-28

    The absorption of H/sub ..cap alpha../ line radiation is shown to lead to delay and even to non-monotonic afterglowing if observed along the 'line' of the expanding laser plasma. This makes it possible to explain the emission character of the H/sub ..cap alpha../ line of the O VIII ion (lambda = 10.2 nm) in experiments with 'Novette' set-ups.

  14. The $\\alpha-\\alpha$ fishbone potential revisited

    CERN Document Server

    Day, J P; Elhanafy, M; Smith, E; Woodhouse, R; Papp, Z

    2011-01-01

    The fishbone potential of composite particles simulates the Pauli effect by nonlocal terms. We determine the $\\alpha-\\alpha$ fishbone potential by simultaneously fitting to two-$\\alpha$ resonance energies, experimental phase shifts and three-$\\alpha$ binding energies. We found that essentially a simple gaussian can provide a good description of two-$\\alpha$ and three-$\\alpha$ experimental data without invoking three-body potentials.

  15. Semileptonic Decays

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G.; /SLAC

    2012-10-02

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

  16. ATLAS End Cap toroid in upstanding position

    CERN Multimedia

    2005-01-01

    End Cap toroid The ATLAS End Cap toroid weights 240-ton and is 12-m diameter high. The parts of this vacuum vessel had to be integrated and tested so that End Cap Toroid has no leaks. After that it could be cooled down to 80 K.

  17. Analyses of hydraulic performance of velocity caps

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Degn Eskesen, Mark Chr.; Buhrkall, Jeppe;

    2014-01-01

    The hydraulic performance of a velocity cap has been investigated. Velocity caps are often used in connection with offshore intakes. CFD (computational fluid dynamics) examined the flow through the cap openings and further down into the intake pipes. This was combined with dimension analyses...

  18. 21 CFR 888.3000 - Bone cap.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  19. Dynamic Modeling of an Evapotranspiration Cap

    Energy Technology Data Exchange (ETDEWEB)

    Jacob J. Jacobson; Steven Piet; Rafael Soto; Gerald Sehlke; Harold Heydt; John Visser

    2005-10-01

    The U.S. Department of Energy is scheduled to design and install hundreds of landfill caps/barriers over the next several decades and these caps will have a design life expectancy of up to 1,000 years. Other landfill caps with 30 year design lifetimes are reaching the end of their original design life; the changes to these caps need to be understood to provide a basis for lifetime extension. Defining the attributes that make a successful cap (one that isolates the waste from the environment) is crucial to these efforts. Because cap systems such as landfill caps are dynamic in nature, it is impossible to understand, monitor, and update lifetime predictions without understanding the dynamics of cap degradation, which is most often due to multiple interdependent factors rather than isolated independent events. In an attempt to understand the dynamics of cap degradation, a computer model using system dynamics is being developed to capture the complex behavior of an evapotranspiration cap. The specific objectives of this project are to capture the dynamic, nonlinear feedback loop structures underlying an evapotranspiration cap and, through computer simulation, gain a better understanding of long-term behavior, influencing factors, and, ultimately, long-term cap performance.

  20. Alpha One Foundation

    Science.gov (United States)

    ... Tested Find Support Find Doctor What Is Alpha-1? Alpha-1 Antitrypsin Deficiency (Alpha-1) is a ... results for inhaled augmentation More News Our Number One Goal: Find a cure for Alpha-1. Website ...

  1. Traceability and the new CAP

    OpenAIRE

    Maraveyas, Napoleon N.; Doukas, Yannis El.

    2009-01-01

    The Common Agricultural Policy (CAP) was strongly criticized for the food safety crises of the 1990s which included Bovine Spongiform Encephalopathy (BSE), dioxin, foot and mouth disease and swine fever to name a few. Even though the first rules on food safety date from the very early days of the EU, a need was recognized to replace a number of these rules accumulated through the years, whose implementation was difficult to monitor, with a simpler and more comprehensive approach. The result w...

  2. Microscopic description of α-decay from superdeformed nuclei

    International Nuclear Information System (INIS)

    Superdeformed nuclei have been intensively investigated, both experimentally and theoretically, during the last decade. We have studied in this paper alpha decay from superdeformed nuclei. For this we have solved exactly the problem of penetration of the alpha particle through a deformed barrier. We have found that approximate treatments of the penetrability in terms of the deformation, as e. g. the WKB approximation or the classical treatment, are not valid for deformations larger than β2∼ 0.3. We have also presented a formalism to calculate the formation amplitude of alpha particles in superdeformed nuclei, a number which is necessary in evaluating the absolute decay widths. Since this calculation requires the use of single-particle states that can describe processes occurring outside the nuclear surface, we introduced a representation consisting of the eigenvalues of two different harmonic oscillator potentials. The low lying members of the representation correspond to the standard single-particle states used to describe bound properties, while the high lying members correspond to the eigenvalues of a shallow harmonic oscillator potential. Within this representation we used the HFB approximation to describe the structure of the superdeformed nuclei. This single-particle basis allows for a much faster convergency of the computed formation amplitude in the region beyond the nuclear surface, where the interaction becomes practically a Coulomb repulsion between the emitted alpha particle and the daughter nucleus. We can therefore perform calculations which would otherwise be prohibitive. We have thus found that the formation amplitude (and the corresponding alpha decay probability) decreases with the difference between the quadrupole deformations in the mother and daughter nuclei, although this is not a big effect. We assumed that the mother nucleus decays by electromagnetic transitions to the head of a superdeformed band. From here we considered that alpha decay

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

    CERN Document Server

    Pollmann, Tina; Kuźniak, 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.

  4. Perturbative expansion of tau hadronic spectral function moments and alpha_s extractions

    OpenAIRE

    Beneke, Martin; Boito, Diogo; Jamin, Matthias

    2012-01-01

    Various moments of the hadronic spectral functions have been employed in the determination of the strong coupling alpha_s from tau decays. In this work we study the behaviour of their perturbative series under different assumptions for the large-order behaviour of the Adler function, extending previous work on the tau hadronic width. We find that the moments can be divided into a small number of classes, whose characteristics depend only on generic features of the moment weight function and A...

  5. A split active site couples cap recognition by Dcp2 to activation

    OpenAIRE

    Floor, Stephen N.; Jones, Brittnee N.; Hernandez, Gail A.; Gross, John D.

    2010-01-01

    Decapping by Dcp2 is an essential step in 5′-3′ mRNA decay. In yeast, decapping requires an open-to-closed transition in Dcp2, though the link between closure and catalysis remains elusive. Here we show using NMR that cap binds conserved residues on both the catalytic and regulatory domains of Dcp2. Lesions in the cap-binding site on the regulatory domain reduce the catalytic step two orders of magnitude and block formation of the closed state whereas Dcp1 enhances the catalytic step by a fac...

  6. Heavy element and actinide decay data: UKHEDD-2 data files

    International Nuclear Information System (INIS)

    A re-evaluation has been made of the decay data for 126 heavy elements and actinides of direct application in nuclear fuel cycle calculations. Computer-based data files have been produced in ENDF/B-VI format, including lists of the references used to produce the proposed decay schemes and comments that identify their inadequacies. These evaluated data include half-lives, average decay energies, branching ratios, alpha, beta and gamma-ray energies and emission probabilities, internal conversion coefficients, spontaneous fission decay data and all associated uncertainties. (author)

  7. Gaseous alpha emitter diffusion studies using alpha track method

    International Nuclear Information System (INIS)

    Using a very accurate and sensitive analysis method such as alpha track method, the SSNTD group was able to undertake studies on the atomic and molecular processes taking place at low speed and/or very low concentrations, such as diffusion of gaseous alpha radionuclides in gaseous media. For practical application reasons, we began to study the diffusion in air for gaseous alpha radionuclides and aerosols carrying solid alpha radionuclides. The used alpha radionuclides were: Rn-222, as gaseous radionuclide and its solid descendants genetically related, attached to different particles from air, as radioactive aerosols. The source was included into an air tight device with a very well known volume. After 40 days, the radioactive equilibrium was established for all descendants, so that in the device there were the Rn-222 and its descendants, each of them having the same activity. The relative amount/activity ratio of each decay product, at any duration, for any initial mass of Ra-226 parent radionuclide, were calculated using the code UURASE, based on the Bateman general equations, for computing the U-238 radioactive series gamma accumulation. This was adapted for alpha accumulation as ALFAURASE programme. The device which contains the Ra-226 source can be coupled to the calibration system or to the diffusion system, without destroying the radioactive equilibrium. At this coupling, only the radioactive concentration is changed due to the variation of the volume. First of all the device was used for calibrating the CR-39 track detectors for both Rn-222 gaseous radionuclide and aerosol concentration measurements using, in the coupled calibration system, a special 'detector-container' equipped/or not with a filter used for radioactive aerosol stopping. The track detectors CR-39 were etched in NaOH 30%, for 7 hours at 70 deg. C and their studies were performed by optical microscopy using a stereo-microscope Wild M7S and a binocular Zeiss Jena microscope. (authors)

  8. Remote Optical Detection of Alpha Radiation

    International Nuclear Information System (INIS)

    Alpha emitting radiation sources are typically hard to detect with conventional detectors due to the short range of alpha particles in the air. However, previous studies have shown that remote detection of alpha radiation is possible by measuring the ionization-induced fluorescence of air molecules. The alpha-induced ultraviolet (UV) light is mainly emitted by molecular nitrogen and its fluorescence properties are well known. The benefit of this method is the long range of UV photons in the air. Secondly, the detection is possible also under a strong beta and gamma radiation backgrounds as they do not cause localized molecular excitation. In this work, the optical detection was studied using two different detection schemes; spectral separation of fluorescence from the background lighting and coincidence detection of UV photons originating from a single radiative decay event. Our spectrally integrated measurements have shown that one alpha decay event yields up to 400 fluorescence photons in the air and all these UV photons are induced in a 5 ns time-window. On the other hand, the probability of a background coincidence event in 5 ns scale is very rare compared to the number of background photons. This information can be applied in fluorescence coincidence filtering to discriminate the alpha radiation initiated fluorescence signal from much more intense background lighting. A device called HAUVA (Handheld Alpha UV Application) was built during this work for demonstration purposes. HAUVA utilizes spectral filtering and it is designed to detect alpha emitters from a distance of about 40 cm. Using specially selected room lighting, the device is able to separate 1 kBq alpha emitter from the background lighting with 1 second integration time. (author)

  9. Effect of Low Electric Fields on Alpha Scintillation Light Yield in Liquid Argon

    CERN Document Server

    Agnes, P; Alexander, T; Alton, A K; Asner, D M; Back, H O; Baldin, B; Biery, K; Bocci, V; Bonfini, G; Bonivento, W; Bossa, M; Bottino, B; Brigatti, A; Brodsky, J; Budano, F; Bussino, S; Cadeddu, M; Cadoni, M; Calaprice, F; Canci, N; Candela, A; Caravati, M; Cariello, M; Carlini, M; Catalanotti, S; Cavalcante, P; Chepurnov, A; Cicalò, C; Cocco, A G; Covone, G; D'Angelo, D; D'Incecco, M; Davini, S; De Cecco, S; De Deo, M; De Vincenzi, M; Derbin, A; Devoto, A; Di Eusanio, F; Di Pietro, G; Dionisi, C; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Giagu, S; Giganti, C; Giovanetti, G K; Goretti, A M; Granato, F; Gromov, M; Guan, M; Guardincerri, Y; Hackett, B R; Herner, K; Hughes, D; Humble, P; Hungerford, E V; Ianni, A; James, I; Johnson, T N; Jollet, C; Keeter, K; Kendziora, C L; Koh, G; Korablev, D; Korga, G; Kubankin, A; Li, X; Lissia, M; Loer, B; Lombardi, P; Longo, G; Ma, Y; Machulin, I N; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, C J; Meregaglia, A; Meyers, P D; Milincic, R; Miller, J D; Montanari, D; Monte, A; Mount, B J; Muratova, V N; Musico, P; Napolitano, J; Agasson, A Navrer; Odrowski, S; Oleinik, A; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Parmeggiano, S; Pelczar, K; Pelliccia, N; Pocar, A; Pordes, S; Pugachev, D A; Qian, H; Randle, K; Ranucci, G; Razeti, M; Razeto, A; Reinhold, B; Renshaw, A L; Rescigno, M; Riffard, Q; Romani, A; Rossi, B; Rossi, N; Rountree, D; Sablone, D; Saggese, P; Sands, W; Savarese, C; Schlitzer, B; Segreto, E; Semenov, D A; Shields, E; Singh, P N; Skorokhvatov, M D; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Trinchese, P; Unzhakov, E V; Verducci, M; Vishneva, A; Vogelaar, B; Wada, M; Walker, S; Wang, H; Wang, Y; Watson, A W; Westerdale, S; Wilhelmi, J; Wojcik, M M; Xiang, X; Xiao, X; Xu, J; Yang, C; Zhong, W; Zhu, C; Zuzel, G

    2016-01-01

    Measurements were made of scintillation light yield of alpha particles from the $^{222}$Rn decay chain within the DarkSide-50 liquid argon time projection chamber. The light yield was found to increase as the applied electric field increased, with alphas in a 200 V/cm electric field exhibiting a $\\sim$2% increase in light yield compared to alphas in no field.

  10. Measurement of the CKM Angle alpha with the B-factories.

    Energy Technology Data Exchange (ETDEWEB)

    Bevan, Adrian; /Liverpool U.

    2005-12-21

    B-meson decays involving b {yields} u transitions are sensitive to the Unitarity Triangle angle {alpha} (or {phi}{sub 2}). The B-factories at SLAC and KEK have made significant progress toward the measurement of {alpha} in recent years. This paper summarizes the results of the B-factories' constraints on {alpha}.

  11. Digital signal processing for radioactive decay studies

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Madurga, M.; Paulauskas, S. V. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Ackermann, D.; Heinz, S.; Hessberger, F. P.; Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64220, Darmstadt (Germany); Grzywacz, R. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Miernik, K.; Rykaczewski, K. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Tan, H. [XIA LLC, Hayward, CA 94544 (United States)

    2011-11-30

    The use of digital acquisition system has been instrumental in the investigation of proton and alpha emitting nuclei. Recent developments extend the sensitivity and breadth of the application. The digital signal processing capabilities, used predominately by UT/ORNL for decay studies, include digitizers with decreased dead time, increased sampling rates, and new innovative firmware. Digital techniques and these improvements are furthermore applicable to a range of detector systems. Improvements in experimental sensitivity for alpha and beta-delayed neutron emitters measurements as well as the next generation of superheavy experiments are discussed.

  12. Study of heavy particle decay from superheavy elements by SK model

    International Nuclear Information System (INIS)

    Heavy nuclei usually decay by alpha decay or spontaneous fission. These two decay modes are generally the most probable competing processes. Another less probable decay process is cluster radioactivity in which nuclei from carbon to silicon are emitted from Radium to Californium leading to the most stable daughter nucleus, lead. This work reports such a study using the cubic plus Yukawa plus exponential model of Shanmugam and Kamalaharan (SK)

  13. Derivation of a novel formula for α-decay half-life

    International Nuclear Information System (INIS)

    Based on the basic principle of quantal decay of particle, we derive a formula of logarithm of decay half-life of an alpha particle emitting from a radioactive nucleus. The process of decay is understood as the transition of the particle from an isolated quasi-bound state to a scattering state. In this picture, the decay width is a resonance width in the system consisting of an α-cluster and the residual nucleus

  14. Human skeletal uptake of natural alpha radioactivity from {sup 210}Pb-supported {sup 210}Po

    Energy Technology Data Exchange (ETDEWEB)

    Oyedepo, A.C

    1998-06-01

    This thesis contributes to increasing knowledge on the dosimetry of natural alpha-particle radiation in skeletal tissues, particularly in utero, and associated risks of malignancy. Alpha-particle radiation is an established aetiological factor of cancer. In the human body, polonium-210 decayed from skeletal lead-210 ({sup 210}Pb/{sup 210}Po) is the predominant natural alpha-emitter. {sup 210}Pb displaces calcium (Ca) in mineral hydroxyapatite, especially during periods of rapid bone growth and remodelling when Ca is laid down. It was therefore necessary to study alpha activity uptake and calcification concurrently within bone. Human studies were undertaken on: fetal vertebrae, 17 - 42 weeks of gestation, 74 samples; adult vertebrae, 40 - 95 years, 40 samples; and adult ribs, 20 - 95 years, 51 samples. Specimens were unconcentrated and weighed <5 g each. TASTRAK alpha-particle autoradiography was used to assess the bone activity concentration and spatial microdistribution of {sup 210}Pb/{sup 210}Po. Alpha track data were resolved by specially written software named SPATS (Selection Program for Analysing Track Structures). Ca and phosphorus (P) were biochemically determined. Results were examined for trends in bone type, gender and chronological ageing in humans. The main research findings were: 1) The Ca content of fetal vertebrae increased linearly at a weekly rate of 0.2g Ca 100 g{sup -1} wet bone (typical values of 2, 4, 6 g 100 g{sup -1} at 16, 26 and 36 weeks). 2) The P concentration also increased with advancing fetal age. 3) The Ca:P bone weight ratio rose from 1.7 to 2.2 by 32 gestational weeks. 4) The overall range in bone {sup 210}Pb/{sup 210}Po alpha activity was 0.25 - 1.1 Bq kg{sup -1} with correlation between activity concentration and fetal age (0.47 {+-} 0.05 Bq kg{sup -1} for 17 - 26 weeks, 0.67 {+-} 0.04 Bq kg{sup -1} for 32 - 42 weeks). 5) The correlation between increased alpha radioactivity and increased Ca concentration approximating to 0

  15. Satellite altimeter remote sensing of ice caps

    OpenAIRE

    Rinne, Eero Juhani

    2011-01-01

    This thesis investigates the use of satellite altimetry techniques for measuring surface elevation changes of ice caps. Two satellite altimeters, Radar Altimeter 2 (RA-2) and Geoscience Laser Altimeter System (GLAS) are used to assess the surface elevation changes of three Arctic ice caps. This is the first time the RA-2 has been used to assess the elevation changes of ice caps - targets much smaller than the ice sheets which are the instrument’s primary land ice targets. Algor...

  16. Extreme alpha-clustering in the 18O nucleus

    CERN Document Server

    Johnson, E D; Goldberg, V Z; Brown, S; Robson, D; Crisp, A M; Cottle, P D; Fu, C; Giles, J; Green, B W; Kemper, K W; Lee, K; Roeder, B T; Tribble, R E

    2009-01-01

    The structure of the 18O nucleus at excitation energies above the alpha decay threshold was studied using 14C+alpha resonance elastic scattering. A number of states with large alpha reduced widths have been observed, indicating that the alpha-cluster degree of freedom plays an important role in this N not equal Z nucleus. However, the alpha-cluster structure of this nucleus is very different from the relatively simple pattern of strong alpha-cluster quasi-rotational bands in the neighboring 16O and 20Ne nuclei. A 0+ state with an alpha reduced width exceeding the single particle limit was identified at an excitation energy of 9.9+/-0.3 MeV. We discuss evidence that states of this kind are common in light nuclei and give possible explanations of this feature.

  17. Synthesis, Characterization, and Tribological Behavior of Oleic Acid Capped Graphene Oxide

    Directory of Open Access Journals (Sweden)

    Tiedan Chen

    2014-01-01

    Full Text Available Graphene oxide (GO nanosheets were prepared by modified Hummers and Offeman methods. Furthermore, oleic acid (OA capped graphene oxide (OACGO nanosheets were prepared and characterized by means of Fourier transform-infrared spectroscopy (FT-IR, transmission electron microscopy (TEM, and X-ray diffraction (XRD. At the same time, the friction and wear properties of OA capped graphite powder (OACG, OACGO, and oleic acid capped precipitate of graphite (OACPG as additives in poly-alpha-olefin (PAO were compared using four-ball tester and SRV-1 reciprocating ball-on-disc friction and wear tester. By the addition of OACGO to PAO, the antiwear ability was improved and the friction coefficient was decreased. Also, the tribological mechanism of the GO was investigated.

  18. Auto-correlation and variance-to-mean measurements in a subcritical core obeying multiple alpha-modes

    Energy Technology Data Exchange (ETDEWEB)

    Bergloef, Carl, E-mail: calle@neutron.kth.se [Department of Reactor Physics, KTH Royal Institute of Technology, SE-106 91 Stockholm (Sweden); Fernandez-Ordonez, Manuel; Villamarin, David; Becares, Vicente; Gonzalez-Romero, Enrique M. [Nuclear Innovation Group, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Bournos, Victor [Joint Institute for Power and Nuclear Research, National Academy of Sciences, Akad. Krasina str. 99, Minsk (Belarus); Munoz-Cobo, Jose-Luis [Dept Ingenieria Quimica y Nuclear, Universidad Politechnica, Camino de Vera 14, 46022 Valencia (Spain)

    2011-02-15

    Neutron noise measurements based on the Rossi-{alpha} and Feynman-{alpha} methodologies have been performed in a heterogeneous subcritical system. It is shown that the traditional single alpha-mode formulations of the Rossi-{alpha} and Feynman-{alpha} methods are not applicable due to the presence of higher alpha-modes. Formalisms taking into account multiple alpha-modes are applied resulting in satisfactory results. Three alpha-modes could be identified using the Rossi-{alpha} method, whereas only two could be obtained using the Feynman-{alpha} method. In the Feynman-{alpha} case, the possibility to obtain the fastest decaying alpha-mode was diminished due to detector dead time effects. It was found that the slowest decaying alpha-mode does not exactly correspond to the prompt decay found in pulsed neutron source measurements, which confirms the results of previous studies. Strengths and weaknesses of the multiple alpha-mode Rossi-{alpha} and Feynman-{alpha} methods observed in this study are pointed out.

  19. Time-resolved and temperature-dependent photoluminescence studies on CdTe/ZnTe quantum dots with different ZnTe capping layer thicknesses

    International Nuclear Information System (INIS)

    We investigate the effects of the capping layer thickness on the optical properties of CdTe/ZnTe quantum dots (QDs). The time-resolved photoluminescence (PL) measurements used to study the carrier dynamics show a shorter decay time for CdTe/ZnTe QDs with decreasing thickness of the ZnTe cap layer due to an increase in the nonradiative surface recombination rate. The activation energy of the electrons confined in the CdTe/ZnTe QDs, as obtained from the temperature-dependent PL spectra, decreases with the thickness of the ZnTe cap layer. These results indicate that the carrier dynamics and activation energy of CdTe/ZnTe QDs are affected by the thickness of the ZnTe cap layer. - Highlights: ► Optical properties of CdTe/ZnTe quantum dots (QDs) are investigated. ► Different ZnTe capping layer thicknesses are used for the QDs. ► QD photoluminescence peak shifts to a higher energy with cap layer thickness increase. ► Decay time of QDs decreases with cap layer thickness decrease. ► Activation energy of QDs increases with cap layer thickness increase

  20. Boundary Harnack principle for $\\Delta + \\Delta^{\\alpha/2}$

    OpenAIRE

    Chen, Zhen-Qing; Kim, Panki; Song, Renming; Vondraček, Zoran

    2009-01-01

    For $d\\geq 1$ and $\\alpha \\in (0, 2)$, consider the family of pseudo differential operators $\\{\\Delta+ b \\Delta^{\\alpha/2}; b\\in [0, 1]\\}$ on $\\R^d$ that evolves continuously from $\\Delta$ to $\\Delta + \\Delta^{\\alpha/2}$. In this paper, we establish a uniform boundary Harnack principle (BHP) with explicit boundary decay rate for nonnegative functions which are harmonic with respect to $\\Delta +b \\Delta^{\\alpha/2}$ (or equivalently, the sum of a Brownian motion and an independent symmetric $\\a...

  1. Cluster decay in osmium isotopes using Hartree-Fock-Bogoliubov theory

    Science.gov (United States)

    Ashok, Nithu; Joseph, Deepthy Maria; Joseph, Antony

    2016-02-01

    Cluster radioactivity is a rare cold nuclear process which is intermediate between alpha decay and spontaneous fission. The present work is a theoretical investigation of the feasibility of alpha decay and cluster radioactivity from proton rich Osmium (Os) isotopes with mass number ranging from 162-190. Osmium forms a part of the transition region between highly deformed and spherical nuclei. Calculations have been done using unified fission model and Hartree-Fock-Bogoliubov (HFB) theory. We have chosen only those decays with half-lives falling in measurable range. Geiger-Nuttall plot has been successfully reproduced. The isotope which is most favorable to each decay mode has a magic daughter nucleus.

  2. Nature mangement, landscape and the CAP

    NARCIS (Netherlands)

    Brouwer, F.M.; Godeschalk, F.E.

    2004-01-01

    The integration of nature management, landscape and environmental concerns into the Common Agricultural Policy (CAP) has gained momentum with the CAP reforms adopted in June 2003. The report explores instruments and approaches that contribute to the inte-gration of nature conservation and landscape

  3. Microtubule dynamics: Caps, catastrophes, and coupled hydrolysis

    DEFF Research Database (Denmark)

    Flyvbjerg, H.; Holy, T.E.; Leibler, S.

    1996-01-01

    An effective theory is formulated for the dynamics of the guanosine triphosphate (GTP) cap believed to stabilize growing microtubules. The theory provides a ''coarse-grained'' description of the cap's dynamics. ''Microscopic'' details, such as the microtubule lattice structure and the fate of its...... data. A constant nonzero catastrophe rare, identical for both microtubule ends, is predicted at large growth rates. The delay time for dilution-induced catastrophes is stochastic with a simple distribution that fits the experimental one and, like the experimental one, does not depend on the rate of....... A recent experimental result for the size of the minimal cap that can stabilize a microtubule is shown to agree with the result predicted by the cap model, after its parameters have been extracted from previous experimental results. Thus the effective theory and cap model presented here provide a...

  4. Decay studies of a long lived high spin isomer of /sup 210/Bi

    Energy Technology Data Exchange (ETDEWEB)

    Tuggle, D.G.

    1976-08-01

    A source of approximately 30 ..mu..g of pure (> 90%) /sup 210m/Bi (J..pi.. = 9-) was prepared by irradiating /sup 209/Bi in a nuclear reactor. After chemical separations to remove /sup 210/Po from the irradiated bismuth sample were completed, the /sup 210/Bi was electromagnetically separated from the /sup 209/Bi by a series of two isotope separations to create the source mentioned above. This source was then used to conduct alpha, conversion electron, gamma, gamma-gamma coincidence, and alpha-gamma coincidence spectroscopic studies of the decay of /sup 210m/Bi. The partial half life for the alpha decay of /sup 210m/Bi was measured as 3.0 x 10/sup 6/ yr. A lower limit of 10/sup 13/ years was set for the partial half life for the decay of /sup 210m/Bi to /sup 210/Po. Alpha decay of /sup 210m/Bi to 8 excited states of /sup 206/Tl was observed. A lower limit of 10/sup -4/% was set for the branching ratio of the parity forbidden alpha decay of /sup 210/Bi to the /sup 206/Ti ground state. Theoretical decay rates for the alpha decays of /sup 210m/Bi, /sup 210/Bi, /sup 211/Po, and /sup 211m/Po were calculated using the method developed by Hans Mang. A comparison of the calculated and experimentally measured alpha decay rates of /sup 210m/Bi showed good agreement for the relative alpha decay rates.

  5. Is the Double Giant Dipole Resonance Process Responsible for Alpha Emission in Ternary Fission?

    Institute of Scientific and Technical Information of China (English)

    HAN Hong-Yin(韩洪银); WAND Yi-Hua(王屹华); G.Mouze

    2001-01-01

    The Monte Carlo program built on the double giant dipole resonance model proposed by Mouze et al. [Nuovo Cimento A 110(1997)1097] was employed to calculate the energy spectrum of alpha particles emitted in the spontaneous ternary fission of 252Cf. It has been found that in the case of the zero orbital angular momentum of alpha particles in the alpha decay of the fragments, the measured alpha spectrum can be reproduced approximately by the model without any adjustable parameter.

  6. Study of the ${\\beta}$-decay of $^{12}$B

    CERN Multimedia

    2002-01-01

    We propose to study the ${\\beta}$-decay of $^{12}$B with a modern segmented Si-detector array to get new and much improved information on states in $^{12}$C above the ${\\alpha}$-threshold. These states mainly decay into final states of three ${\\alpha}$-particles and their study therefore is a challenge for nuclear spectroscopy. The properties of these states is of high current interest for nuclear astrophysics and for the nuclear many-body problem in general. We ask for a total of 15 shifts.

  7. Fission decay of $^{282}$Cn studied using cranking inertia

    CERN Document Server

    Poenaru, D N

    2014-01-01

    Superheavy nuclei produced until now are decaying mainly by $\\alpha$~emission and spontaneous fission. Calculated $\\alpha$~decay half-lives are in agreement with experimental data within one order of magnitude. The discrepancy between theory and experiment can be as high as ten orders of magnitude for spontaneous fission. We analyze a way to improve the accuracy by using the action integral based on cranking inertia and a potential barrier computed by the macroscopic-microscopic method with a two-center shell model. Illustrations are given for $^{282}$Cn which has a measured fission half-life.

  8. Weak decays. [Lectures, phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  9. decays to baryons

    Indian Academy of Sciences (India)

    Torsten Leddig

    2012-11-01

    From inclusive measurements, it is known that about 7% of all mesons decay into final states with baryons. In these decays, some striking features become visible compared to mesonic decays. The largest branching fractions come with quite moderate multiplicities of 3–4 hadrons. We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

  10. Precise predictions for B -> Xc tau nu decay distributions

    CERN Document Server

    Ligeti, Zoltan

    2014-01-01

    We derive precise standard model predictions for the dilepton invariant mass and the tau energy distributions in inclusive B -> Xc tau nu decay. We include Lambda_QCD^2/m_b^2 and alpha_s corrections using the 1S short-distance mass scheme, and estimate shape function effects near maximal tau energy. These results can improve the sensitivity of b -> c tau nu related observables to beyond standard model physics.

  11. 3CAPS – a structural AP–site analogue as a tool to investigate DNA base excision repair

    Science.gov (United States)

    Schuermann, David; Scheidegger, Simon P.; Weber, Alain R.; Bjørås, Magnar; Leumann, Christian J.; Schär, Primo

    2016-01-01

    Abasic sites (AP-sites) are frequent DNA lesions, arising by spontaneous base hydrolysis or as intermediates of base excision repair (BER). The hemiacetal at the anomeric centre renders them chemically reactive, which presents a challenge to biochemical and structural investigation. Chemically more stable AP-site analogues have been used to avoid spontaneous decay, but these do not fully recapitulate the features of natural AP–sites. With its 3′–phosphate replaced by methylene, the abasic site analogue 3CAPS was suggested to circumvent some of these limitations. Here, we evaluated the properties of 3CAPS in biochemical BER assays with mammalian proteins. 3CAPS-containing DNA substrates were processed by APE1, albeit with comparably poor efficiency. APE1-cleaved 3CAPS can be extended by DNA polymerase β but repaired only by strand displacement as the 5′–deoxyribophosphate (dRP) cannot be removed. DNA glycosylases physically and functionally interact with 3CAPS substrates, underlining its structural integrity and biochemical reactivity. The AP lyase activity of bifunctional DNA glycosylases (NTH1, NEIL1, FPG), however, was fully inhibited. Notably, 3CAPS-containing DNA also effectively inhibited the activity of bifunctional glycosylases on authentic substrates. Hence, the chemically stable 3CAPS with its preserved hemiacetal functionality is a potent tool for BER research and a potential inhibitor of bifunctional DNA glycosylases. PMID:26733580

  12. Radiative Corrections to the 2E1 Decay Rate of the 2s-State in Hydrogen-Like Atoms

    OpenAIRE

    Karshenboim, Savely G.; Ivanov, Vladimir G.

    1997-01-01

    Radiative corrections to the 2E1 decay width of the 2s-state in the low-Z hydrogen-like system are examined within logarithmic approximation. The correction is found to be 2.025(1) alpha (Z alpha)^2 / pi log(Z alpha)^2 in units of the non-relativistic rate.

  13. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    Energy Technology Data Exchange (ETDEWEB)

    d' Enterria, David [CERN; Skands, Peter Z. [Monash U.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  14. Genetic ablation of root cap cells in Arabidopsis

    OpenAIRE

    Tsugeki, Ryuji; Fedoroff, Nina V.

    1999-01-01

    The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of...

  15. CAPS and INMS Major Accomplishments

    Science.gov (United States)

    Waite, J. Hunter

    2014-05-01

    The Cassini-Huygens Ion Neutral Mass Spectrometer (Cassini INMS) and the Cassini Plasma Spectrometer (CAPS) have provided "discovery" science at Titan, Enceladus, Rhea/Dione, and throughout the magnetosphere of Saturn during the course of the mission. In this talk we will review some of the major scientific achievements: 1) the discovery of an extremely complex ion neutral organic chemistry in Titan's upper atmosphere that forms the building blocks for aerosol processes below, 2) the discovery of gases and grains emanating from Enceladus' cryo-geysers that tell us about chemical processes in an interior sea, 3) the first direct compositional measurements of sputtered icy moon surfaces, 4) the clearest example to date of the complex plasma interchange processes that occur in rapidly rotating magnetospheres of gas giants, initiating global dynamic processes that enable Saturn to shed the plasma from Enceladus' plume, and complete with a myriad of longitudinal and solar local-time variations, and 5) the dominance of Enceladus water outgassing as a source of magnetospheric plasma that stretches out to Titan and provides oxygen that can convert Titan's rich nitrile populations into amino acids.

  16. CP violation in strange baryon decays: A report from Fermilab experiment 871

    Energy Technology Data Exchange (ETDEWEB)

    James, C.; Volk, J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K. [Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of (China); Choong, W.S.; Fuzesy, R.; Gidal, G.; Luk, K.B.; Turko, B.; Zyla, P. [University of California and Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Felix, J.; Moreno, G.; Sosa, M. [University of Guanajuato, 37000 Leon (Mexico); Burnstein, R.A.; Chakravorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; White, C.G.; White, S.L. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Leros, N.; Perroud, J.P. [University of Lausanne, CH-1015 Lausanne (Switzerland); Gustafson, H.R.; Longo, M.J.; Lopez, F. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Papavassiliou, V. [New Mexico State University, Las Cruces, New Mexico 88003 (United States); Clark, K.; Jenkins, M. [University of South Alabama, Mobile, Alabama 36688 (United States); Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Nelson, K. [University of Virginia, Charlottesville, Virginia 22901 (United States)

    1999-02-01

    Fermilab experiment 871, {ital HyperCP}, is a search for direct CP violation in {Xi} and {Lambda} hyperon decays. A non-zero value in the asymmetry parameter A, defined in terms of the decay parameter products {alpha}{sub {Xi}}{alpha}{sub {Lambda}} and {alpha}{sub {bar {Xi}}}{alpha}{sub {bar {Lambda}}}, would be unambiguous evidence for direct CP violation. The first data-taking run finished at the end of 1997 and accumulated over one billion {Xi}{sup {minus}} and {bar {Xi}}{sup +} decays. A sensitivity in A of {approx}10{sup {minus}4} is expected. A review of CP violation in hyperon decays is given, the {ital HyperCP} detector is described, and the status of the data analysis is discussed. {copyright} {ital 1999 American Institute of Physics.}

  17. Radon monitor and control system based upon alpha particle detection

    International Nuclear Information System (INIS)

    A system is designed for monitoring or controlling the level of radon in indoor air, based upon measuring alpha particles due to the decay of radon or its daughter atoms. In one embodiment, the alpha particle decay of radon itself is detected and analyzed to control a vent in the heating and air conditioning system to automatically keep the radon level below a preselected level. In another embodiment, the daughter atoms 218Po and 214Po are collected from the indoor air and their alpha particle decays are analyzed to provide a sensitive monitor of radon levels or to control vents in the HVAC system to reduce radon concentrations to permissible levels. In addition, the system provides information on the quality of the air filter and indicates when it needs servicing

  18. Ab initio alpha-alpha scattering

    CERN Document Server

    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.

  19. The pharmaceutical vial capping process: Container closure systems, capping equipment, regulatory framework, and seal quality tests.

    Science.gov (United States)

    Mathaes, Roman; Mahler, Hanns-Christian; Buettiker, Jean-Pierre; Roehl, Holger; Lam, Philippe; Brown, Helen; Luemkemann, Joerg; Adler, Michael; Huwyler, Joerg; Streubel, Alexander; Mohl, Silke

    2016-02-01

    Parenteral drug products are protected by appropriate primary packaging to protect against environmental factors, including potential microbial contamination during shelf life duration. The most commonly used CCS configuration for parenteral drug products is the glass vial, sealed with a rubber stopper and an aluminum crimp cap. In combination with an adequately designed and controlled aseptic fill/finish processes, a well-designed and characterized capping process is indispensable to ensure product quality and integrity and to minimize rejections during the manufacturing process. In this review, the health authority requirements and expectations related to container closure system quality and container closure integrity are summarized. The pharmaceutical vial, the rubber stopper, and the crimp cap are described. Different capping techniques are critically compared: The most common capping equipment with a rotating capping plate produces the lowest amount of particle. The strength and challenges of methods to control the capping process are discussed. The residual seal force method can characterize the capping process independent of the used capping equipment or CCS. We analyze the root causes of several cosmetic defects associated with the vial capping process.

  20. Capping stack: An industry in the making

    Institute of Scientific and Technical Information of China (English)

    Jack Chen; Li Xunke; Xie Wenhui; Kang Yongtian

    2013-01-01

    This paper gives an overview of recent development of the marine well containment system (MWCS)after BP Macondo subsea well blowout occurred on April 20,2010 in the Gulf of Mexico.Capping stack,a hardware utilized to contain blowout well at or near the wellhead is the center piece of MWCS.Accessibility to the dedicated capping stacks is gradually becoming a pre-requirement to obtain the permit for offshore drilling/workover,and the industry for manufacturing,maintenance,transportation and operation of the capping stack is in the making.

  1. Search for the Decay B0 --> rho0rho0

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allison, J; Allmendinger, T; Altenburg, D; Andreotti, M; Angelini, C; Anulli, F; Aston, D; Azzolini, V; Baak, M; Back, J J; Bailey, S; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Barate, R; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Berger, N; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bianchi, F; Biasini, M; Blanc, F; Blaylock, G; Blinov, A E; Blinov, V E; Bloom, P; Bóna, M; Bondioli, M; Bonneaud, G R; Borgland, A W; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Breon, A B; Briand, H; Brochard, F; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bulten, H; Burchat, Patricia R; Button-Shafer, J; Buzzo, A; Côté, D; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, E; Chen, J C; Chen, S; Cheng, B; Cheng, C H; Chevalier, N; Christ, S; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Colecchia, F; Coleman, J P; Contri, R; Convery, M R; Cormack, C M; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L M; Cristinziani, M; Crosetti, G; Çuhadar-Dönszelmann, T; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; Del Buono, L; Della Ricca, G; Di Lodovico, F; Dickopp, M; Dittongo, S; Dong, D; Dorfan, J; Dorigo, A; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckmann, R; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Elsen, E E; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Fabozzi, F; Faccini, R; Fan, S; Farbin, A; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B J; Frey, R; Fritsch, M; Fry, J R; Gabathuler, Erwin; Gaidot, A; Gaillard, J M; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Geddes, N I; Gill, M S; Giorgi, M A; Giraud, P F; Giroux, X; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Graham, M; Grancagnolo, S; Green, M G; Greene, M G; Grenier, G J; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hart, P A; Hartfiel, B L; Harton, J L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hicheur, A; Hill, E J; Hitlin, D G; Höcker, A; Hodgkinson, M C; Hollar, J J; Honscheid, K; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Igonkina, O; Innes, W R; Ivanchenko, V N; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jawahery, A; Jayatilleke, S M; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Knecht, N S; Koch, H; Kocian, M L; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kravchenko, E A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; Lacker, H M; Lae, C K; Lafferty, G D; Lamsa, J; Lanceri, L; Lange, D J; Langenegger, U; Lankford, A J; Laplace, S; Latham, T E; Lau, Y P; Lavin, D; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, H; Libby, J; Lillard, V; Lista, L; Liu, R; LoSecco, J M; Lo Vetere, M; Lockman, W S; Lombardo, V; London, G W; Long, O; Lou, X C; Lu, A; Lü, C; Luitz, S; Luppi, E; Lusiani, A; Lüth, V; Lutz, A M; Lynch, G; Lynch, H L; Lyon, A J; MacFarlane, D B; Macri, M; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Manfredi, P F; Mangeol, D J J; Marchiori, G; Margoni, M; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Meadows, B T; Messner, R; Meyer, T I; Meyer, W T; Miftakov, V; Mihályi, A; Mir, L M; Mohanty, G B; Mohapatra, A K; Mommsen, R K; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M; Morton, G W; Muheim, F; Müller, D R; Müller-Pfefferkorn, R; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; O'Grady, C P; Ocariz, J; Oddone, P J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Otto, S; Ozcan, V E; Paar, H P; Paick, K; Palano, A; Palombo, F; Pan, Y; Panetta, J; Panvini, R S; Paoloni, E; Paolucci, P; Parry, R J; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Perazzo, A; Perl, M; Peruzzi, I M; Petersen, B A; Petersen, T C; Petrak, S; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Pioppi, M; Piredda, G; Pivk, M; Plaszczynski, S; Playfer, S; Pompili, A; Poropat, P; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prepost, R; Pripstein, M; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rama, M; Rankin, P; Ratcliff, B N; Raven, G; Re, V; Reidy, J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roat, C; Roberts, D A; Robertson, S H; Robutti, E; Roe, N A; Röthel, W; Ronan, Michael T; Roney, J M; Rong, G; Roodman, A; Roos, L; Rosenberg, E I; Rotondo, M; Rubin, A E; Ryd, A; Saeed, M A; Safai-Tehrani, F; Saleem, M; Salnikov, A A; Salvatore, F; Samuel, A; Sanders, D A; Sandrelli, F; Santroni, A; Saremi, S; Sarti, A; Satpathy, A; Schalk, T; Schindler, R H; Schott, G; Schrenk, S; Schubert, J; Schubert, Klaus R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Sharma, V; Shelkov, V G; Shen, B C; Simani, M C; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Sloane, R J; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Soha, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spradlin, P; Stängle, H; Steinke, M; Stelzer, J; Stoker, D P; Stroili, R; Strom, D; Stugu, B; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; T'Jampens, S; Tan, P; Tantot, L; Taras, P; Taylor, F; Taylor, G P; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Therin, G; Thiebaux, C; Thiessen, D; Tiozzo, G; Tisserand, V; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Treadwell, E; Vasileiadis, G; Vasseur, G; Vavra, J; Verderi, M; Verkerke, W; Vitale, L; Voci, C; Voena, C; Vuagnin, G; Wagner, G; Wagner, S R; Wagoner, D E; Waldi, R; Walsh, J; Wang, K; Wang, P; Wappler, F R; Watson, A T; Weaver, M; Weidemann, A W; Weinstein, A J R; Wenzel, W A; Wilden, L; Williams, D C; Williams, J C; Willocq, S; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winter, M A; Wisniewski, W J; Wittgen, M; Won, E; Wong, Q K; Wormser, G; Wright, D H; Wright, D M; Wu, J; Wu, S L; Xie, Y; Yamamoto, R K; Yang, S; Yarritu, A K; Ye, S; Yéche, C; Yi, J; Young, C C; Yu, Z; Yumiceva, F X; Yushkov, A N; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Zito, M; De Sangro, R; Del Re, D; La Vaissière, C de

    2004-01-01

    The B --> rho0 rho0 decay mode is searched for in a data sample of about 227 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. No significant signal is observed, and an upper limit of 1.1 x 10e-6 (90% C.L.) on the branching fraction is set. Implications on the penguin contribution and constraints on the CKM angle alpha with B --> rho rho decays are discussed. All results are preliminary.

  2. Search for the Decay B^0 -> a^\\pm_1 \\rho^\\mp

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.

    2006-05-10

    The authors present a search for the rare B-meson decay B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}} with {alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}. We use (110 {+-} 1.2) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEp-II asymmetric-energy B Factory at SLAC. They obtain an upper limit of 30 x 10{sup -6} (90% C.L.) for the branching fraction product {Beta}(B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}}) {Beta}({alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}), where they assume that the {alpha}{sub 1}{sup {+-}} decays exclusively to {rho}{sup 0}{pi}{sup {+-}}.

  3. Non-exponential decay of atomic systems

    CERN Document Server

    Ishkhanyan, A M

    2014-01-01

    We discuss the possibility of non-exponential decay of various quantum quasi-stationary systems. This effect can occur at the times which are greater than the lifetime of a considered system. The mechanism for non-exponential depletion of an initial quasi-stationary state is the cutting of the energy spectrum of final continuous states at long times. We first consider the known examples of cold emission of electrons from metal, tunneling alpha-decay of atomic nuclei, and spontaneous decay in two-level systems. The new physical situations discussed are the single-photon atomic ionization by a weak electromagnetic field and tunneling ionization of atoms by a strong low-frequency electromagnetic field. In both cases the decay obeys a power-law dependence on the (long) interaction time. We find that the most promising possibility for observing non-exponential decay at long times is the single-photon ionization of negative atomic ions near the threshold.

  4. Workshop on High-precision $\\alpha_s$ measurements from LHC to FCC-ee

    CERN Document Server

    d'Enterria, David

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experiment...

  5. Rare Decays at LHCb

    Science.gov (United States)

    Hall, Sam

    2014-04-01

    Rare decays of beauty and charm hadrons provide an effective method of testing the Standard Model and probing possible new physics scenarios. The LHCb experiment has published a variety of interesting results in this field, some of which are presented here. In particular the measurements of the branching fractions of B(s)0 → μ+μ- which, in combination with CMS, resulted in the first observation of the Bs0 → μ+μ- decay. Other topics include searches for the rare decay D0 → μ+μ-, the lepton flavour violating decays B(s)0 → e±μ∓, and the observation of the ψ(4160) resonance in the region of low recoil in B+ → K+μ+μ- decay. New results on the angular analysis of the decay B0 → K*0μ+μ- with form factor independent observables are also shown.

  6. Circumpolar Active-Layer Permafrost System (CAPS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Circumpolar Active-Layer Permafrost System (CAPS) contains over 100 data sets pertaining to permafrost and frozen ground topics. It also contains detailed...

  7. C-CAP Land Cover, Niihau, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  8. C-CAP Land Cover, Molokai, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  9. C-CAP Land Cover, Lanai, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  10. Mapping of p140Cap phosphorylation sites

    DEFF Research Database (Denmark)

    Repetto, Daniele; Aramu, Simona; Boeri Erba, Elisabetta;

    2013-01-01

    protein, in which both EPLYA/EGLYA tyrosines were converted to phenylalanine, was no longer tyrosine phosphorylated, despite the presence of other tyrosine residues in p140Cap sequence. Moreover, this mutant lost its ability to bind the C-terminal Src kinase (Csk), previously shown to interact with p140...... phosphorylation and tunes its interactions with other regulatory molecules via post-translation modification. In this work, using mass spectrometry, we found that p140Cap is in vivo phosphorylated on tyrosine (Y) within the peptide GEGLpYADPYGLLHEGR (from now on referred to as EGLYA) as well as on three serine...... residues. Consistently, EGLYA has the highest score of in silico prediction of p140Cap phosphorylation. To further investigate the p140Cap function, we performed site specific mutagenesis on tyrosines inserted in EGLYA and EPLYA, a second sequence with the same highest score of phosphorylation. The mutant...

  11. C-CAP Hawaii 2005 Land Cover

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  12. C-CAP Land Cover, Maui, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of land derived from high resolution imagery and was analyzed according to the Coastal Change Analysis Program (C-CAP) protocol to determine...

  13. Ab initio alpha-alpha scattering

    Science.gov (United States)

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

    2015-12-01

    Processes such as the scattering of alpha particles (4He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei—nuclei with even and equal numbers of protons and neutrons—is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the ‘adiabatic projection method’ to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  14. Ab initio alpha-alpha scattering.

    Science.gov (United States)

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

    2015-12-01

    Processes such as the scattering of alpha particles ((4)He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei--nuclei with even and equal numbers of protons and neutrons--is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the 'adiabatic projection method' to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  15. Decay of 120Ba

    International Nuclear Information System (INIS)

    The decay of 120Ba has been studied with an on-line isotope separator. Its half-life was determined to be t1/2=24±2 s. A decay scheme is proposed, based on γ-γ, γ-X, and γ-β+ coincidence measurements, which takes account of all 16 observed γ rays. The total decay energy was measured to be QEC=50±0.3 MeV

  16. Effective Majorana neutrino decay

    CERN Document Server

    Duarte, Lucía; Peressutti, Javier; Sampayo, Oscar A

    2016-01-01

    We study the decay of heavy sterile Majorana neutrinos according to the interactions obtained from an effective general theory. We describe the two and three-body decays for a wide range of neutrino masses. The results obtained and presented in this work could be useful for the study of the production and detection of this particles in a variety of high energy physics experiments and astrophysical observations. We show in different figures the dominant branching ratios and the total decay width.

  17. Design and implementation of the CAPS receiver

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, based on analyses of the Chinese Area Positioning System (CAPS) satellite (GEO satellite) resources and signal properties, the signal power at the port of the receiver antenna is estimated, and the implementation projects are presented for a switching band C to band L CAPS C/A code receiver integrated with GPS receiver suite and for a CAPS dual frequency P code receiver. A microstrip receiving antenna is designed with high sensitivity and wide beam orientation, the RF front end of the C/A code and P code receivers, and a processor is designed for the navigation baseband. A single frequency CAPS C/A code receiver and a CAPS dual frequency P code receiver are built at the same time. A software process flow is provided, and research on relatively key techniques is also conducted, such as signal searching, code loop and carrier loop algorithms, a height assistant algorithm, a dual frequency difference speed measurement technique, a speed measurement technique using a single frequency source with frequency assistance, and a CAPS time correcting algorithm, according to the design frame of the receiver hardware. Research results show that the static plane positioning accuracy of the CAPS C/A code receiver is 20.5-24.6 m, height accuracy is 1.2-12.8 m, speed measurement accuracy is 0.13-0.3 m/s, dynamic plane positioning accuracy is 24.4 m, height accuracy is 3.0 m, and speed measurement accuracy is 0.24 m/s. In the case of C/A code, the timing accuracy is 200 ns, and it is also shown that the positioning accuracy of the CAPS precise code receiver (1σ ) is 5 m from south to north, and 0.8 m from east to west. Finally, research on positioning accuracy is also conducted.

  18. UNDERSTANDING FARMERS’ RESPONSES TO CAP REFORM

    OpenAIRE

    Menozzi, Davide; Fioravanzi, Martina; Donati, Michele

    2014-01-01

    The 2014-2020 Common Agricultural Policy (CAP) reform defines new rules for farmers including regionalization, crop diversification and ecological focus area (EFA). This paper aims to evaluate farmers’ intention to modify their behaviour because of the CAP reform, using the Theory of Planned Behaviour (TPB). A questionnaire was submitted to 71 Italian durum wheat producers assessing their intention to change durum wheat surface and to maintain as EFA part of the arable land. Subjective norms ...

  19. Alpha indirect conversion radioisotope power source

    Energy Technology Data Exchange (ETDEWEB)

    Sychov, Maxim [TRACE Photonics Inc., 1680 West Polk, Charleston, IL 61920 (United States)], E-mail: msychov@yahoo.com; Kavetsky, Alexandr; Yakubova, Galina; Walter, Gabriel; Yousaf, Shahid; Lin, Qian; Chan, Doris; Socarras, Heather; Bower, Kenneth [TRACE Photonics Inc., 1680 West Polk, Charleston, IL 61920 (United States)

    2008-02-15

    Advantages of radioisotope-powered electric generators include long service life, wide temperature range operation and high-energy density. We report development of a long-life generator based on indirect conversion of alpha decay energy. Prototyping used 300 mCi Pu-238 alpha emitter and AlGaAs photovoltaic cells designed for low light intensity conditions. The alpha emitter, phosphor screens, and voltaic arrays were assembled into a power source with the following characteristics: I{sub sc}=14 {mu}A; U{sub oc}=2.3 V; power output -21 {mu}W. Using this prototype we have powered an eight-digit electronic calculator and wrist watch.

  20. The Oklo Constraints on Alpha-Decay Half-Lives

    Science.gov (United States)

    Chaffin, Eugene; Molgaard, Joshua

    2003-11-01

    Beginning with Shlyakhter in 1976, Oklo natural reactor data have been used by many authors to put limits on the time variation of "constants" such as the fine structure constant and the strong coupling constant. The Sm-149 resonance absorption data constrain the depth of the nuclear potential well to a small margin of error, determined by various unknowns, such as the reactor temperature. Although this change in well depth is slight, nevertheless at certain critical values the number of nodes in the wavefunction can change precipitously, with a corresponding change in other quantities. We show that even these small variations could allow the U-238 half-life to vary by more than one order of magnitude.

  1. The Oklo Constraints on Alpha-Decay Half-Lives

    CERN Document Server

    Chaffin, E

    2003-01-01

    The Oklo data constrain the depth of the nuclear potential well to a small margin of error, determined by various unknowns, such as the reactor temperature. However, we show that even these small variations could allow the U-238 half-life to vary by more than one order of magnitude.

  2. Faddeev calculation of 3 alpha and alpha alpha Lambda systems using alpha alpha resonating-group method kernel

    CERN Document Server

    Fujiwara, Y; Kohno, M; Suzuki, Y; Baye, D; Sparenberg, J M

    2004-01-01

    We carry out Faddeev calculations of three-alpha (3 alpha) and two-alpha plus Lambda (alpha alpha Lambda) systems, using two-cluster resonating-group method kernels. The input includes an effective two-nucleon force for the alpha alpha resonating-group method and a new effective Lambda N force for the Lambda alpha interaction. The latter force is a simple two-range Gaussian potential for each spin-singlet and triplet state, generated from the phase-shift behavior of the quark-model hyperon-nucleon interaction, fss2, by using an inversion method based on supersymmetric quantum mechanics. Owing to the exact treatment of the Pauli-forbidden states between the clusters, the present three-cluster Faddeev formalism can describe the mutually related, alpha alpha, 3 alpha and alpha alpha Lambda systems, in terms of a unique set of the baryon-baryon interactions. For the three-range Minnesota force which describes the alpha alpha phase shifts quite accurately, the ground-state and excitation energies of 9Be Lambda are...

  3. News on C-12 from beta-decay studies

    NARCIS (Netherlands)

    Fynbo, HOU; Diget, CA; Prezado, Y; Aysto, J; Bergmann, UC; Cederkall, J; Dendooven, P; Fraile, LM; Franchoo, S; Fulton, BR; Huang, W; Huikari, J; Jeppesen, H; Jokinen, A; Jonson, B; Jones, P; Koster, U; Meister, M; Nilsson, T; Nyman, G; Borge, MJG; Riisager, K; Rinta-Antila, S; Vogelius, IS; Tengblad, O; Turrion, M; Wang, Y; Weissman, L; Wilhelmsen, K

    2004-01-01

    We discuss the importance of the spectroscopic properties of the resonances of C-12 just above the 3alpha-threshold, and review the existing experimental information of this region with emphasis on 0(+) and 2(+) states. A new experimental approach for studying the beta-decays of B-12 and N-12 is pre

  4. The GT resonance revealed in beta sup + -decay using new experimental techniques

    CERN Document Server

    Algora, A; Rubio, B; Taín, J L; Agramunt, J; Blomqvist, J M; Batist, L; Borcea, R; Collatz, R; Gadea, A; Gerl, J; Gierlik, M; aGórska, M; Guilbaud, O; Grawe, H; Hellström, M; Hu, Z; Janas, Z; Karny, M; Kirchner, R; Kleinheinz, P; Liu, W; Martínez, T; Moroz, F; Plochocki, A; Rejmund, M; Roeckl, E; Rykaczewski, K; Shibata, M; Szerypo, J; Wittmann, V

    1999-01-01

    The GT beta decay of sup 1 sup 5 sup 0 Ho has been studied with a Total Absorption Spectrometer (TAS), with an array of 6 Euroball CLUSTER Ge detectors (the CLUSTER CUBE), and with an alpha detector. The three techniques complement each other. The results provide the first observation of an extremely sharp resonance in GT beta decay.

  5. Measurements of sin2alpha/phi2 from B -> pipi, rhopi and rhorho modes

    CERN Document Server

    Bevan, A; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Nesom, G; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Fabozzi, F; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2004-01-01

    B meson decays involving b -> u transitions are sensitive to the unitarity triangle angle alpha (or phi2). The BaBar and Belle experiments have studied B-meson decays to pipi, rhopi and rhorho final states. It is possible to combine these measurements to constrain alpha with a precision of O(10 degrees) and a central value of approximately 100 degrees. These results are consistent with Standard Model expectations.

  6. Evaluation of (alpha,n) Induced Neutrons as a Background for Dark Matter Experiments

    OpenAIRE

    Mei, D.-M.; C. Zhang; Hime, A.

    2008-01-01

    Neutrons from ($\\alpha$,n) reactions through thorium and uranium decays are important sources of background for direct dark matter detection. The neutron yields and energy spectra from a range of materials that are used to build dark matter detectors are calculated and tabulated. In addition to thorium and uranium decays, we found that $\\alpha$ particles from samarium, often the dopant of the window materials of photomultiplier tubes (PMT), are also an important source of neutron yield. The r...

  7. Approximate formulation of redistribution in the Ly-alpha, Ly-beta, H-alpha system

    Science.gov (United States)

    Cooper, J.; Ballagh, R. J.; Hubeny, I.

    1989-01-01

    Simple approximate formulas are given for the coupled redistribution of Ly-alpha, Ly-beta, and H-alpha, by using well-defined approximations to an essentially exact formulation. These formulas incorporate all the essential physics including Raman scattering, lower state radiative decay, and correlated terms representing emission during a collision which must be retained in order that the emission coefficients are properly behaved in the line wings. Approximate expressions for the appropriate line broadening parameters are collected. Finally, practical expressions for the source functions are given. These are formulated through newly introduced nonimpact redistribution functions, which are shown to be reasonably approximated by existing (ordinary and generalized) redistribution functions.

  8. Rare Semileptonic Charm Decays

    CERN Document Server

    de Boer, Stefan

    2015-01-01

    An analysis of charm mesons decaying semileptonically via Flavor Changing Neutral Currents is presented. We calculate the Wilson coefficients within the Standard Model. A window in the decay distribution, where physics beyond the Standard Model could be measured is identified. Exemplary, we study effects of leptoquark models.

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

    OpenAIRE

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

    2006-01-01

    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 p...

  10. Exploring clustering in alpha-conjugate nuclei using the thick target inverse kinematic technique for multiple alpha emission

    Science.gov (United States)

    Barbui, M.; Hagel, K.; Gauthier, J.; Wuenschel, S.; Goldberg, V. Z.; Zheng, H.; Giuliani, G.; Rapisarda, G.; Kim, E.-J.; Liu, X.; Natowitz, J. B.; Desouza, R. T.; Hudan, S.; Fang, D.

    2015-10-01

    Searching for alpha cluster states analogous to the 12C Hoyle state in heavier alpha-conjugate nuclei can provide tests of the existence of alpha condensates in nuclear matter. Such states are predicted for 16O, 20Ne, 24Mg, etc. at excitation energies slightly above the decay threshold. The Thick Target Inverse Kinematics (TTIK) technique can be successfully used to study the breakup of excited self-conjugate nuclei into many alpha particles. The reaction 20Ne + α at 11 and 13 AMeV was studied at Cyclotron Institute at Texas A&M University. Here the TTIK method was used to study both single α-particle emission and multiple α-particle decays. Due to the limited statistics, only events with alpha multiplicity up to three were analyzed. The analysis of the three α-particle emission data allowed the identification of the Hoyle state and other 12C excited states decaying into three alpha particles. The results will be shown and compared with other data available in the literature. Another experiment is planned in August 2015 to study the system 28Si + α at 15 AMeV. Preliminary results will be shown. Supported by the U.S. DOE and the Robert A. Welch Foundation, Grant No. A0330.

  11. Effects of closure cap and liner on contaminant release rates from grouted wastes

    International Nuclear Information System (INIS)

    This paper describes a groundwater modeling study of waste disposal concepts using grouted waste forms. The focus of the study is on the effects of clay caps and concrete vaults on contaminant migration. The authors modeled three waste disposal scenarios: (1) Grouted waste was solidified in an earthen trench and covered with soil, there was no vault and no cap; (2) grouted waste was solidified in an earthen trench, the entire waste disposal facility was then closed under a clay cap; (3) grouted waste was solidified in a concrete vault and protected by the same closure as in 2. Because of the huge contrast in hydraulic conductivities and highly non-linear multi-phase flow characteristics, these waste disposal concepts presented a difficult problem for numerical simulation. Advanced fluid flow and contaminant transport codes were used to solve the problem. Among the codes tested, ECLIPSE out-performed other codes in speed, accuracy (smaller material balance errors) and capability in handling sophisticated scenarios. The authors used nitrate as a tracer for the simulation. Nitrate does not absorb in the solid phase and does not decay. As a result, predicted release rate based on nitrate is conservative. They also assumed that the facility is intact for 10,000 years. In other words, properties of the materials used for this study do not change with time. Predicted peak flux for the no vault and no closure case was 5.8 x 10-4 per year at 12 years. If a clay cap was installed, predicted peak flux was 8.5 x 10-5 per year at 110 years. If the grout was disposed in a concrete vault and covered by a clay cap, predicted peak flux became 4.4 x 10-6 per year at 8,000 years. Both concrete liner and clay cap can reduce the rate of contaminant release to the water table and delay the peak time

  12. Protective capping and surface passivation of III-V nanowires by atomic layer deposition

    Directory of Open Access Journals (Sweden)

    Veer Dhaka

    2016-01-01

    Full Text Available Low temperature (∼200 °C grown atomic layer deposition (ALD films of AlN, TiN, Al2O3, GaN, and TiO2 were tested for protective capping and surface passivation of bottom-up grown III-V (GaAs and InP nanowires (NWs, and top-down fabricated InP nanopillars. For as-grown GaAs NWs, only the AlN material passivated the GaAs surface as measured by photoluminescence (PL at low temperatures (15K, and the best passivation was achieved with a few monolayer thick (2Å film. For InP NWs, the best passivation (∼2x enhancement in room-temperature PL was achieved with a capping of 2nm thick Al2O3. All other ALD capping layers resulted in a de-passivation effect and possible damage to the InP surface. Top-down fabricated InP nanopillars show similar passivation effects as InP NWs. In particular, capping with a 2 nm thick Al2O3 layer increased the carrier decay time from 251 ps (as-etched nanopillars to about 525 ps. Tests after six months ageing reveal that the capped nanostructures retain their optical properties. Overall, capping of GaAs and InP NWs with high-k dielectrics AlN and Al2O3 provides moderate surface passivation as well as long term protection from oxidation and environmental attack.

  13. Protective capping and surface passivation of III-V nanowires by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dhaka, Veer, E-mail: veer.dhaka@aalto.fi; Perros, Alexander; Kakko, Joona-Pekko; Haggren, Tuomas; Lipsanen, Harri [Department of Micro- and Nanosciences, Micronova, Aalto University, P.O. Box 13500, FI-00076 (Finland); Naureen, Shagufta; Shahid, Naeem [Research School of Physics & Engineering, Department of Electronic Materials Engineering, Australian National University, Canberra ACT 2601 (Australia); Jiang, Hua; Kauppinen, Esko [Department of Applied Physics and Nanomicroscopy Center, Aalto University, P.O. Box 15100, FI-00076 (Finland); Srinivasan, Anand [School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, S-164 40 Kista (Sweden)

    2016-01-15

    Low temperature (∼200 °C) grown atomic layer deposition (ALD) films of AlN, TiN, Al{sub 2}O{sub 3}, GaN, and TiO{sub 2} were tested for protective capping and surface passivation of bottom-up grown III-V (GaAs and InP) nanowires (NWs), and top-down fabricated InP nanopillars. For as-grown GaAs NWs, only the AlN material passivated the GaAs surface as measured by photoluminescence (PL) at low temperatures (15K), and the best passivation was achieved with a few monolayer thick (2Å) film. For InP NWs, the best passivation (∼2x enhancement in room-temperature PL) was achieved with a capping of 2nm thick Al{sub 2}O{sub 3}. All other ALD capping layers resulted in a de-passivation effect and possible damage to the InP surface. Top-down fabricated InP nanopillars show similar passivation effects as InP NWs. In particular, capping with a 2 nm thick Al{sub 2}O{sub 3} layer increased the carrier decay time from 251 ps (as-etched nanopillars) to about 525 ps. Tests after six months ageing reveal that the capped nanostructures retain their optical properties. Overall, capping of GaAs and InP NWs with high-k dielectrics AlN and Al{sub 2}O{sub 3} provides moderate surface passivation as well as long term protection from oxidation and environmental attack.

  14. Decay of hypernuclei

    International Nuclear Information System (INIS)

    The pionic and non-mesonic decays of hypernuclei are discussed. In the first part, various decay processes which could be useful to obtain information of hypernuclear structure are discussed. The experimental data concerning the pionic and non-mesonic decays are discussed in the second part. As the experimental data, there are only few lifetime data and some crude data on the non-mesonic to π decay ratio. In the third and the fourth parts, some theoretical analyses are made on the pionic and the nonmesonic decays. DDHF calculation was performed for Λ and N systems by using Skyrme type ΛN and NN effective interactions. A suppression factor of the order of 10-3 for A nearly equal 100 was obtained. (Aoki, K.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John M.; Ellis, R.Keith

    2012-04-01

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

  16. 75 FR 49527 - Caps Visual Communications, LLC; Black Dot Group; Formerly Known as Caps Group Acquisition, LLC...

    Science.gov (United States)

    2010-08-13

    ... Employment and Training Administration Caps Visual Communications, LLC; Black Dot Group; Formerly Known as... Adjustment Assistance on June 24, 2010, applicable to workers of Caps Visual Communications, LLC, Black Dot..., Caps Visual Communications, LLC, Black Dot Group, formerly known as Caps Group Acquisition,...

  17. Review of alpha_s determinations

    CERN Document Server

    Pich, Antonio

    2013-01-01

    The present knowledge on the strong coupling is briefly summarized. The most precise determinations of alpha_s, at different energies, are reviewed and compared at the Z mass scale, using the predicted QCD running. The impressive agreement achieved between experimental measurements and theoretical predictions constitutes a beautiful and very significant test of Asymptotic Freedom, establishing QCD as the fundamental theory of the strong interaction. The world average value of the strong coupling is found to be alpha_s(M_Z^2)= 0.1186 \\pm 0.0007.

  18. Scenarios for a cap beyond 2013; Implications for EU27 agriculture and the cap budget

    NARCIS (Netherlands)

    Helming, J.F.M.; Terluin, I.J.

    2011-01-01

    An ex ante analysis of a set of five policy components (proposed post 2013 CAP measures) has been carried out for the 2014-2020 period, based on the EC Communication The CAP towards 2020 of 18 November 2010. The policy components are defined in such a way that they focus on the contribution of farme

  19. Estimated α-decay half-lives of even-even Z=120 SHEs in the range of neutron number 172 ≤ N ≤ 186

    International Nuclear Information System (INIS)

    The super heavy elements formed by either way of cold fusion or hot fusion process, are primarily decay through alpha-particle emission and after successive emission of alpha-particles it undergoes to spontaneous fission. Alpha particle emission from super heavy elements is an important and unique part of all the decay process. Different theoretical approaches are using alpha-decay characteristics as a tool to investigate the nuclear structure information of the unstable nuclei such as the ground state energy, the ground state and isomeric state half-life, the nuclear spin and parity, the nuclear deformation, the clustering, the shell effects and the interaction between nuclei

  20. Study of the decay asymmetry parameter and CP violation parameter in the Lambda(c)+ ---> Lambda pi+ decay

    Energy Technology Data Exchange (ETDEWEB)

    Link, J.M.; Yager, P.M.; /UC, Davis; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; /Rio de Janeiro, CBPF; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; /CINVESTAV, IPN; Agostino, L.; Cinquini, L.; Cumalat,; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN,

    2005-09-01

    Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter a{sub {Lambda}{sub c}} in {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +} decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter {Alpha} {triple_bond} a{sub {Lambda}{sub c}} + a{sub {ovr {Lambda}{sub c}}}/a{sub {Lambda}{sub c}} - a{sub {ovr {Lambda}{sub c}}}. We obtain a{sub {Lambda}{sub c}} = -0.78 {+-} 0.16 {+-} 0.13 and {Alpha} = -0.07 {+-} 0.19 {+-} 0.12 where errors are statistical and systematic.

  1. Analysis on the positioning precision of CAPS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As a newly developed satellite positioning system, the Chinese Area Positioning System (CAPS) is a typical direct sequence spread spectrum ranging system like GPS. The positioning precision of such navigation signals depends on many factors, including the pseudo-code rate, the signal to noise ratio, the processing methods for tracking loops and so on. This paper describes the CAPS link budget, the solution approach for CAPS positioning, focusing on the autocorrelation function feature of C/A code signals. The CAPS signal measurement precision is studied by the software approach together with theoretical analysis of the range resolution. Because the conventional Delay Lock Loop (DLL) is vul- nerable to the impact of noise, a narrow correlator and multiple correlators as well as the corresponding discrimination methods of phases are proposed, which improves the robustness of DLL and the code-phase resolution of the measurement. The results show that the improvement of the DLL structure and the discrimination method are the most important way to improve the ranging resolution. Theoretical analysis and experimental results show that a CAPS receiver could reach a 20-m positioning precision by using three satellites with a supported height from an altimeter.

  2. Martian north polar cap summer water cycle

    CERN Document Server

    Brown, Adrian J; Becerra, Patricio; Byrne, Shane

    2016-01-01

    A key outstanding question in Martian science is 'are the polar caps gaining or losing mass and what are the implications for past, current and future climate?' To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls=120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for ...

  3. Analysis on the positioning precision of CAPS

    Institute of Scientific and Technical Information of China (English)

    JI YuanFa; SUN XiYan

    2009-01-01

    As a newly developed satellite positioning system,the Chinese Area Positioning System (CAPS) Is a typical direct sequence spread spectrum ranging system like GPS.The positioning precision of such navigation signals depends on many factors,including the pseudo-code rate,the signal to noise ratio,the processing methods for tracking loops and so on.This paper describes the CAPS link budget,the solution approach for CAPS positioning,focusing on the autocorrelation function feature of C/A code signals.The CAPS signal measurement precision is studied by the software approach together with theoretical analysis of the range resolution.Because the conventional Delay Lock Loop (DLL) is vulnerable to the impact of noise,a narrow correlator and multiple correlatore as well as the corresponding discrimination methods of phases are proposed,which improves the robustness of DLL and the code-phase resolution of the measurement.The results show that the Improvement of the DLL structure and the discrimination method are the most important way to improve the ranging resolution.Theoretical analysis and experimental results show that a CAPS receiver could reach a 20-m positioning precision by using three satellites with a supported height from an altimeter.

  4. Corrosion resistance of pseudo-spin-valve systems: Pd vs. Ta capping layers

    Science.gov (United States)

    Matthes, P.; Albrecht, M.

    2016-08-01

    An analysis of both magnetic and magneto-transport properties in dependence of the corrosion resistance is presented for a pseudo-spin-valve (PSV) system with different capping layers. The magnetoresistive part of the sample consists of a [Co/Pd] multilayer with perpendicular magnetic anisotropy and a single Co layer with in-plane easy axis separated by a Cu spacer, forming a PSV system with crossed anisotropies. The samples were annealed under ambient conditions up to temperatures of 200 °C to facilitate the corrosion process. Whereas the magnetic properties are stable up to 100 °C independent of the capping layer, the giant magnetoresistance (GMR) effect is more sensitive on annealing. In case of Pd as capping layer, the GMR of the pseudo-spin-valve considerably degrades already after annealing at 60 °C, whereby even by thickening of the Pd layer up to 10 nm, no pronounced improvement was obtained. On the contrary, for Ta as capping layer the GMR ratio stays constant upon heating up to 100 °C, followed by a comparable moderate decay for even higher annealing temperatures.

  5. Nasute termite soldier frontal gland secretions. 1. Structure of Trinervi-2. beta. ,3. cap alpha. ,9. cap alpha. -triol 9-O acetate, a novel diterpene from Trinervitermes soldiers

    Energy Technology Data Exchange (ETDEWEB)

    Prestwich, G.D. (International Center of Insect Physiology and Ecology, Nairobi, Kenya); Tanis, S.P.; Springer, J.P.; Clardy, J.

    1976-09-15

    One of the major constituents, ''TG-2,'' of the soldier secretions of Trinervitermes gratiosus Sjostedt were studied by x-ray diffraction. The structure was determined to be a novel diterpene skeleton with a bridgehead double bond in an 11-membered ring. Bond angles and lengths were discussed, and a computer generated perspective drawing of the compound was presented. (DDA)

  6. New Precise Measurements of the $\\Xi^{0} \\to \\Lambda \\gamma$ and $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ Decay Asymmetries

    CERN Document Server

    Batley, J R; Lazzeroni, C; Munday, D J; Patel, M; Slater, M W; Wotton, S A; Arcidiacono, R; Bocquet, G; Ceccucci, A; Cundy, D; Doble, N; Falaleev, V; Gatignon, L; Gonidec, A; Grafstrom, P; Kubischta, W; Mikulec, I; Norton, A; Panzer-Steindel, B; Rubin, P; Wahl, H; Goudzovski, E; Hristov, P; Kekelidze, V; Litov, L; Madigozhin, D; Molokanova, N; Potrebenikov, Yu; Stoynev, S; Zinchenko, A; Monnier, E; Swallow, E; Winston, R; Sacco, R; Walker, A; Baldini, W; Gianoli, A; Dalpiaz, P; Frabetti, P L; Martini, M; Petrucci, F; Savrie, M; Scarpa, M; Calvetti, M; Collazuol, G; Iacopini, E; Ruggiero, G; Bizzeti, A; Lenti, M; Veltri, M; Behler, M; Eppard, K; Eppard, M; Hirstius, A; Kleinknecht, K; Koch, U; Marouelli, P; Masetti, L; Moosbrugger, U; Morales-Morales, C; Peters, A; Wanke, R; Winhart, A; Dabrowski, A; Fonseca Martin, T; Velasco, M; Cenci, P; Lubrano, P; Pepe, M; Anzivino, G; Imbergamo, E; Lamanna, G; Michetti, A; Nappi, A; Petrucci, M C; Piccini, M; Valdata, M; Cerri, C; Fantechi, R; Costantini, F; Fiorini, L; Giudici, S; Pierazzini, G; Sozzi, M; Mannelli, I; Cheshkov, C; Cheze, J B; De Beer, M; Debu, P; Gouge, G; Marel, G; Mazzucato, E; Peyaud, B; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Biino, C; Cartiglia, N; Marchetto, F; Pastrone, N; Clemencic, M; Goy Lopez, S; Menichetti, E; Wislicki, W; Dibon, H; Jeitler, M; Markytan, M; Neuhofer, G; Widhalm, L

    2010-01-01

    The decay asymmetries of the weak radiative Hyperon decays $\\Xi^{0}\\to \\Lambda \\gamma$ and $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52000 $\\Xi^{0}\\to \\Lambda \\gamma$ and 15000 $\\Xi^{0} \\to \\Sigma^{0}\\gamma$ decays, we obtain for the decay asymmetries $\\alpha_{\\Xi^{0}\\to \\Lambda\\gamma}$ = -0.704 +- 0.019$_{stat}$ +- 0.064$_{syst}$ and $\\alpha_{\\Xi^{0}\\to \\Sigma^{0}\\gamma}$ = -0.729 +- 0.030$_{stat}$ +- 0.076$_{syst}$, respectively. These results are in good agreement with previous experiments, but more precise.

  7. Maximum Alpha to Minimum Fission Pulse Amplitude for a Parallel-Plate and Hemispherical Cf-252 Ion-Chamber Instrumented Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Oberer, R.B.

    2000-12-07

    In an instrumented Cf-252 neutron source, it is desirable to distinguish fission events which produce neutrons from alpha decay events. A comparison of the maximum amplitude of a pulse from an alpha decay with the minimum amplitude of a fission pulse shows that the hemispherical configuration of the ion chamber is superior to the parallel-plate ion chamber.

  8. Radiative corrections in K --> 3 pi decays

    CERN Document Server

    Bissegger, M; Gasser, J; Kubis, B; Rusetsky, A

    2008-01-01

    We investigate radiative corrections to K --> 3 pi decays. In particular, we extend the non-relativistic framework developed recently to include real and virtual photons and show that, in a well-defined power counting scheme, the results reproduce corrections obtained in the relativistic calculation. Real photons are included exactly, beyond the soft-photon approximation, and we compare the result with the latter. The singularities generated by pionium near threshold are investigated, and a region is identified where standard perturbation theory in the fine structure constant alpha may be applied. We expect that the formulae provided allow one to extract S-wave pi pi scattering lengths from the cusp effect in these decays with high precision.

  9. Weak Decay of Hypernuclei

    CERN Document Server

    Alberico, W M

    2004-01-01

    The focus of these Lectures is on the weak decay modes of hypernuclei, with special attention to Lambda-hypernuclei. The subject involves many fields of modern theoretical and experimental physics, from nuclear structure to the fundamental constituents of matter and their interactions. The various weak decay modes of Lambda-hypernuclei are described: the mesonic mode and the non-mesonic ones. The latter are the dominant decay channels of medium--heavy hypernuclei, where, on the contrary, the mesonic decay is disfavoured by Pauli blocking effect on the outgoing nucleon. In particular, one can distinguish between one-body and two-body induced decays. Theoretical models employed to evaluate the (partial and total) decay widths of hypernuclei are illustrated, and their results compared with existing experimental data. Open problems and recent achievements are extensively discussed, in particular the determination of the ratio Gamma_n/Gamma_p, possible tests of the Delta I=1/2 rule in non-mesonic decays and the pu...

  10. Capping complex formation at the slow-growing end of the actin filament.

    Science.gov (United States)

    Kostyukova, A S

    2008-12-01

    Actin filaments are polar; their barbed (fast-growing) and pointed (slow-growing) ends differ in structure and dynamic properties. The slow-growing end is regulated by tropomodulins, a family of capping proteins that require tropomyosins for optimal function. There are four tropomodulin isoforms; their distributions vary depending on tissue type and change during development. The C-terminal half of tropomodulin contains one compact domain represented by alternating alpha-helices and beta-structures. The tropomyosin-independent actin-capping site is located at the C-terminus. The N-terminal half has no regular structure; however, it contains a tropomyosin-dependent actin-capping site and two tropomyosin-binding sites. One tropomodulin molecule can bind two tropomyosin molecules. Effectiveness of tropomodulin binding to tropomyosin depends on the tropomyosin isoform. Regulation of tropomodulin binding at the pointed end as well as capping effectiveness in the presence of specific tropomyosins may affect formation of local cytoskeleton and dynamics of actin filaments in cells. PMID:19216712

  11. Review of alpha_s determinations

    OpenAIRE

    Pich, Antonio

    2013-01-01

    The present knowledge on the strong coupling is briefly summarized. The most precise determinations of alpha_s, at different energies, are reviewed and compared at the Z mass scale, using the predicted QCD running. The impressive agreement achieved between experimental measurements and theoretical predictions constitutes a beautiful and very significant test of Asymptotic Freedom, establishing QCD as the fundamental theory of the strong interaction. The world average value of the strong coupl...

  12. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...... crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed...... as a strong ice wave. The ice cap leads to low transmission of energy into the crust such that charges need be larger than in conventional onshore experiments to obtain reliable seismic signals. The strong reflection coefficient at the base of the ice generates strong multiples which may mask for secondary...

  13. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    New measurements of the Σ+ and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K-p → Yπ where Y = Σ+ or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ+ → pγ to Σ+ → pπ0 and Λ → nγ to Λ → nπ0. The photons from weak radiative decays and from π0 decays were detected with modular NaI arrays. (orig.)

  14. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  15. Rare decays at LHCb

    CERN Document Server

    Lafferty, George

    2015-01-01

    We review recent results from the LHCb experiment on studies of particle decays that are forbidden or rare in the Standard Model. The studies include searches for lepton flavour violating decays of the $\\tau$ lepton and the $B$ and $D$ mesons, and of $B$ and $D$ meson decays that would be mediated by Majorana neutrinos. Results are also presented for the rare processes $B_s \\to \\mu^+\\mu^-$ and $B^0 \\to \\mu^+\\mu^-$, $D^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$, $b \\to s\\gamma$ transitions, and $B \\to K^{(*)}\\mu^+\\mu^-$.

  16. Alpha-cluster Condensations in Nuclei and Experimental Approaches for their Studies

    CERN Document Server

    von Oertzen, Wolfram

    2010-01-01

    The formation of alpha-clusters in nuclei close to the decay thresholds is discussed. These states can be considered to be boson-condensates, which are formed in a second order phase transition in a mixture of nucleons and alpha-particles. The de Broglie wavelength of the alpha-particles is larger than the nuclear diameter, therefore the coherent properties of the alpha-particles give particular effects for the study of such states. The states are above the thresholds thus the enhanced emission of multiple-alphas into the same direction is observed. The probability for the emission of multiple-alphas is not described by Hauser-Feshbach theory for compound nucleus decay.

  17. Martian north polar cap summer water cycle

    Science.gov (United States)

    Brown, Adrian J.; Calvin, Wendy M.; Becerra, Patricio; Byrne, Shane

    2016-10-01

    A key outstanding question in Martian science is "are the polar caps gaining or losing mass and what are the implications for past, current and future climate?" To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls = 120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for regions closer to the pole, and later for regions close to the periphery of the cap. The observations and calculations presented herein estimate that on average a water ice layer ∼70 microns thick is deposited during the Ls = 135-164 period. This is far larger than the results of deposition on the south pole during summer, where an average layer 0.6-6 microns deep has been estimated by Brown et al. (2014) Earth Planet. Sci. Lett., 406, 102-109.

  18. Non-leptonic decays of beauty decays

    CERN Document Server

    Bigi, Ikaros I; Shifman, M; Uraltsev, N; Vainshtein, A I

    1994-01-01

    "Anyone who keeps the ability to see beauty never grows old" (Franz Kafka). In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values.

  19. Study of alpha activity in the region of rare earths

    International Nuclear Information System (INIS)

    The alpha decay half-lives of the Nd144, Cd152 and Er162 isotopes were redetermined using Ilford L4 nuclear emulsions charged with rare earth complexes of natural isotopic composition. The results were compared to results obtained by other authors, and with results calculated by potential barrier penetration theory. (M.C.K.)

  20. Search for direct CP violation in {lambda} and {xi} hyperon decays

    Energy Technology Data Exchange (ETDEWEB)

    White, C. G.; Burnstein, R. A.; Carmack, M.; Chakravorty, A.; Chan, A.; Chen, Y. C.; Choong, W. S.; Clark, K.; Crisler, M.; Drapala, J.; Dukes, E. C.; Durandet, C.; Felix, J.; Gidal, G.; Gustafson, H. R.; Ho, C.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, M.; Kaplan, D. M.; Kou, Z.; Lederman, L. M.; Leros, N.; Longo, M. J.; Lopez, F.; Lopez, G.; Luebke, W.; Luk, K. B.; Nelson, K.; Papavassiliou, V.; Perroud, J. P.; Rajaram, D.; Rubin, H. A.; Saleh, N.; Sheng, J.; Sosa, M.; Teng, P. K.; Turko, B.; Volk, J.; White, S. L.; Yu, C.; Yu, Z.; Zyla, P

    1999-03-01

    A sensitive search for direct CP violation in {upsilon}{sup -} ({xi}-bar{sup +}) and {lambda} ({lambda}-bar) decays is underway at FNAL. Experiment E871 (HyperCP) intends to perform a precision measurement of the angular distribution of protons (anti-protons) with respect to the helicity axis in the rest frame of the {lambda} ({lambda}-bar). The slopes of these distributions give the decay parameters {alpha}{sub {upsilon}}{alpha}{sub {lambda}} and {alpha}{sub {xi}}{sub -bar}{alpha}{sub {lambda}}{sub -bar}. An asymmetry parameter A in terms of these decay parameters has been defined for which a non-zero value would be unambiguous evidence for direct CP violation. Theoretical predictions for A range from no asymmetry up to {approx} 10{sup -3}. HyperCP expects to measure A with an uncertainty of {approx} 2 x 10{sup -4}.

  1. Pharmacy benefit caps and the chronically ill.

    Science.gov (United States)

    Joyce, Geoffrey F; Goldman, Dana P; Karaca-Mandic, Pinar; Zheng, Yuhui

    2007-01-01

    In this paper we examine medication use among retirees with employer-sponsored drug coverage both with and without annual benefit limits. We find that pharmacy benefit caps are associated with higher rates of medication discontinuation across the most common therapeutic classes and that only a minority of those who discontinue use reinitiate therapy once coverage resumes. Plan members who reach their cap are more likely than others to switch plans and increase their rate of generic use; however, in most cases, the shift is temporary. Given the similarities between these plans and Part D, we make some inferences about reforms for Medicare.

  2. Assembling the CMS yoke end-caps

    CERN Multimedia

    Laurent Guiraud

    2001-01-01

    A crane is used to piece together one of the end-caps that will provide the path for magnetic flux return on the CMS experiment. A total of six end-cap discs will be assembled before being positioned on the barrel yoke to complete the huge 12 500 tonne cylinder yoke. The magnetic field produced will be greater than any other solenoid created to date at 4 T, 100 000 times greater than the Earth's natural magnetic field, and will store enough energy to melt 18 tonnes of gold.

  3. Design and implementation of the CAPS receiver

    Institute of Scientific and Technical Information of China (English)

    HU YongHui; HUA Yu; HOU Lei; WEI JingFa; WU JianFeng

    2009-01-01

    In this paper,baaed on analyses of the Chinese Area Positioning System (CAPS) satellite (GEO satellite) resources and signal properties,the signal power at the port of the receiver antenna is estimated,and the implementation projects are presented for a switching band C to band L CAPS C/A code receiver integrated with GPS receiver suite and for a CAPS dual frequency P code receiver.A microstrip receiving antenna is designed with high sensitivity and wide beam orientation,the RF front end of the C/A code and P code receivers,and a processor is designed for the navigation baseband.A single frequency CAPS C/A code receiver and a CAPS dual frequency P code receiver are built at the same time.A software process flow is provided,and research on relatively key techniques is also conducted,such as signal searching,code loop and carrier loop algorithms,a height assistant algorithm,a dual frequency difference speed measurement technique,a speed measurement technique using a single frequency source with frequency assistance,and a CAPS time correcting algorithm,according to the design frame of the receiver hardware.Research results show that the static plane positioning accuracy of the CAPS C/A code receiver is 20.5-24.6 m,height accuracy is 1.2-12.8 m,speed measurement accuracy is 0.13-0.3 m/s,dynamic plane positioning accuracy is 24.4 m,height accuracy is 3.0 m,and speed measurement accuracy is 0.24 m/s.In the case of C/A code,the timing accuracy is 200 ha,and it is also shown that the positioning accuracy of the CAPS precise code receiver (1σ) is 5 m from south to north,and 0.8 m from east to west.Finally,research on positioning accuracy is also conducted.

  4. Experimental investigation of decay properties of neutron deficient $^{116-118}$Ba isotopes and test of $^{112-115}$Ba beam counts

    CERN Multimedia

    We propose to study decay of neutron deficient isotopes $^{116-118}$Ba using Double Sided Silicon Strip Detector (DSSSD). To study delayed-proton and $\\alpha$-decay branching ratios of $^{116-118}$Ba are of special interest because of their vicinity to the proton drip line. The nuclear life-times and properties of the proton unstable states of Cs isotopes, populated through decay of $^{116-118}$Ba isotopes will be measured. In addition to that we propose beam development of $^{112-115}$Ba to study exotic decay properties of these neutron deficient nuclei and to search for super-allowed $\\alpha$-decay in future.

  5. CLEO Results B Decays

    CERN Document Server

    Cassel, David G

    2001-01-01

    Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements Vcb and Vub using new measurements of the branching fraction and photon energy spectrum of B -> s gamma decays. This report includes: the new CLEO measurements of B -> s gamma decays, Vcb, and Vub; the first results from CLEO III data -- studies of B -> K pi, pi pi, and K Kbar decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

  6. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  7. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

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

  8. Inflaton decay in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Endo, M.; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Yanagida, T.T. [Tokyo Univ. (Japan). Dept. of Physics]|[Tokyo Univ. (Japan). Research Center for the Early Universe

    2007-06-15

    We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3){sub C} gauge interactions. (orig.)

  9. Alpha-resonance structure in $^{11}$C studied via resonant scattering of $^{7}$Be+$\\alpha$ and $^{7}$Be($\\alpha$, $p$) reaction

    CERN Document Server

    Yamaguchi, H; Wakabayashi, Y; Kubono, S; Hashimoto, T; Hayakawa, S; Kawabata, T; Iwasa, N; Teranishi, T; Kwon, Y K; Binh, D N; Khiem, L H; Duy, N N

    2012-01-01

    The resonance structure in $^{11}$C is particularly of interest with regard to the astrophysical $^{7}$Be($\\alpha$, $\\gamma$) reaction, relevant at high temperature, and to the $\\alpha$-cluster structure in $^{11}$C. The measurement was to determine unknown resonance parameters for the high excited states of $^{11}$C. In particular, the $\\alpha$ decay width can be useful information to discuss $\\alpha$ cluster structure in $^{11}$C. New measurements of the $^{7}$Be+$\\alpha$ resonant scattering and the $^{7}$Be($\\alpha$, $p$)$^{10}$B reaction in inverse kinematics were performed for center-of-mass energy up to 5.5 MeV, and the resonances at excitation energies of 8.9--12.7 MeV in the compound $^{11}$C nucleus were studied. Inelastic scattering of $^{7}$Be+$\\alpha$ and the $^{7}$Be($\\alpha$, $p_1$)$^{10}$B$^*$ reaction were also studied with a simultaneous $\\gamma$-ray measurement. The measurements were performed at the low-energy RI beam facility CRIB (CNS Radioactive Ion Beam separator) of the Center for Nucl...

  10. Generalization of symmetric $\\alpha$-stable L\\'evy distributions for $q>1$

    OpenAIRE

    Umarov, Sabir; Tsallis, Constantino; Gell-Mann, Murray; Steinberg, Stanly

    2009-01-01

    The $\\alpha$-stable distributions introduced by L\\'evy play an important role in probabilistic theoretical studies and their various applications, e.g., in statistical physics, life sciences, and economics. In the present paper we study sequences of long-range dependent random variables whose distributions have asymptotic power law decay, and which are called $(q,\\alpha)$-stable distributions. These sequences are generalizations of i.i.d. $\\alpha$-stable distributions, and have not been previ...

  11. Experimental cross section of {sup 144}Sm({alpha},{gamma}){sup 148}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, E. [Atomki, Debrecen (Hungary); Fueloep, Zs. [Atomki, Debrecen (Hungary); Kiss, A.Z. [Atomki, Debrecen (Hungary); Rolfs, C. [Ruhr-Universitaet, Bochum (Germany); Trautvetter, H.-P. [Ruhr-Universitaet, Bochum (Germany); Greife, U. [Ruhr-Universitaet, Bochum (Germany); Junker, M. [Ruhr-Universitaet, Bochum (Germany); Arnould, M. [Universite Libre de Bruxelles, Bruxelles (Belgium); Rayet, M. [Universite Libre de Bruxelles, Bruxelles (Belgium); Oberhummer, H. [Technische Universitaet, Vienna (Austria)

    1997-08-04

    The cross section of the {sup 144}Sm({alpha},{gamma}){sup 148} Gd reaction has been measured in the bombarding energy range of 10.5-13.4 MeV, using activation method based on the off-line {alpha}-activity measurement of the {sup 148}Gd residual nucleus. The long measuring time of the alpha decay demanded the utilization of solid state nuclear track detectors (SSNTD). The first results are compared to the latest statistical model calculations. (orig.).

  12. Open Flavor Strong Decays

    Science.gov (United States)

    García-Tecocoatzi, H.; Bijker, R.; Ferretti, J.; Galatà, G.; Santopinto, E.

    2016-10-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified ^3P_0 model for the amplitudes and the U(7) algebraic model and the hypercentral quark model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  13. Aspects of B decays

    Energy Technology Data Exchange (ETDEWEB)

    Faller, Sven

    2011-03-04

    B-meson decays are a good probe for testing the flavour sector of the standard model of particle physics. The standard model describes at present all experimental data satisfactorily, although some ''tensions'' exist, i.e. two to three sigma deviations from the predictions, in particular in B decays. The arguments against the standard model are thus purely theoretical. These tensions between experimental data and theoretical predictions provide an extension of the standard model by new physics contributions. Within the flavour sector main theoretical uncertainties are related to the hadronic matrix elements. For exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays QCD sum rule techniques, which are suitable for studying hadronic matrix elements, however, with substantial, but estimable hadronic uncertainties, are used. The exploration of new physics effects in B-meson decays is done in an twofold way. In exclusive semileptonic anti B {yields} D{sup (*)}l anti {nu} decays the effect of additional right-handed vector as well as left- and right-handed scalar and tensor hadronic current structures in the decay rates and the form factors are studied at the non-recoil point. As a second approach one studied the non-leptonic B{sup 0}{sub s}{yields}J/{psi}{phi} and B{sup 0}{yields}J/{psi}K{sub S,L} decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B{sup 0}- anti B{sup 0} mixing phase. (orig.)

  14. Open flavor strong decays

    CERN Document Server

    García-Tecocoatzi, H; Ferretti, J; Galatà, G; Santopinto, E

    2016-01-01

    In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified $^3P_0$ model for the amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

  15. Decay-Assisted Laser Spectroscopy of Neutron-Deficient Francium

    CERN Document Server

    Lynch, K M; Bissell, M L; Budincevic, I; Cocolios, T E; De Groote, R P; De Schepper, S; Fedosseev, V N; Flanagan, K T; Franchoo, S; Garcia Ruiz, R F; Heylen, H; Marsh, B A; Neyens, G; Procter, T J; Rossel, R E; Rothe, S; Strashnov, I; Stroke, H H; Wendt, K D A

    2014-01-01

    This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment.

  16. Radioactive airborne effluents and the environmental impact assessment of CAP1400 nuclear power plant under normal operation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qiong; Guo, RuiPing; Zhang, ChunMing; Chen, XiaoQiu; Wang, Bo, E-mail: wangbo@chinansc.cn

    2014-12-15

    Highlights: • Typical radionuclides dispersion from CAP1400 under normal operation was simulated. • Modified Gaussian model considered radioactive decay, dry and wet deposition and so on. • The radioactive impact pathways on the public through atmosphere were compared. • The maximum individual effective dose was lower than the public irradiation limit. - Abstract: China Advanced Passive nuclear power plant with installed capacity reaching to 1400 MW (CAP1400) is independently designed as the China's state-of-the-art third generation nuclear power brand based on AP1000 technology digestion and absorption. The concentration of typical radionuclides dispersed from CAP1400 under normal operation was calculated with modified Gaussian model, considering mixed layer height, dry deposition, wet deposition, radioactive decay and so on. The atmospheric dispersion factors, ground deposition rate, individual dose and public dose were also investigated to estimate the radioactive effects of CAP1400 under normal operation on surrounding environment and human beings. The radioactive impact pathways on the public through atmosphere, such as immersion irradiation in the smoke plume, internal irradiation from ingestion and inhalation and external irradiation from surface deposition were briefly introduced with focus on the comparison of the maximum individual effective dose to different group from atmospheric dispersion. All computation results show that the maximum individual irradiation dose happened to children with total effective irradiation dose of 4.52E−03 mSv/y, which was lower than the public irradiation limit of 0.25 mSv/y.

  17. New ALPHA-2 magnet

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    On 21 June, members of the ALPHA collaboration celebrated the handover of the first solenoid designed for the ALPHA-2 experiment. The magnet has since been successfully installed and is working well.   Khalid Mansoor, Sumera Yamin and Jeffrey Hangst in front of the new ALPHA-2 solenoid. “This was the first of three identical solenoids that will be installed between now and September, as the rest of the ALPHA-2 device is installed and commissioned,” explains ALPHA spokesperson Jeffrey Hangst. “These magnets are designed to allow us to transfer particles - antiprotons, electrons and positrons - between various parts of the new ALPHA-2 device by controlling the transverse size of the particle bunch that is being transferred.” Sumera Yamin and Khalid Mansoor, two Pakistani scientists from the National Centre for Physics in Islamabad, came to CERN in February specifically to design and manufacture these magnets. “We had the chance to work on act...

  18. Alpha Anisotropy Studies of Near-Spherical and Deformed Nuclei

    CERN Multimedia

    Van Duppen, P

    2002-01-01

    % IS329 \\\\ \\\\ Although it was the first decay mode to be discovered, the process of $\\alpha$-particle emission is still poorly understood. A few years ago the first systematic study of anisotropic $\\alpha$-decay triggered renewed theoretical interest. Nevertheless, today the theories are still not adequate enough and more experimental data are urgently needed. We therefore measure the $\\alpha$-anisotropies of the favoured transitions of a number of near-spherical Rn and At isotopes, and of deformed nuclei near A=220. As the different models yield contradictory predictions for the transitions that are investigated, the measurements will allow to discern on their validity. They will at the same time provide the necessary basis for further theoretical developments.

  19. Scheme variations of the QCD coupling and hadronic $\\tau$ decays

    CERN Document Server

    Boito, Diogo; Miravitllas, Ramon

    2016-01-01

    The Quantum Chromodynamics (QCD) coupling, $\\alpha_s$, is not a physical observable of the theory since it depends on conventions related to the renormalization procedure. We introduce a definition of the QCD coupling, denoted by $\\widehat\\alpha_s$, whose running is explicitly renormalization scheme invariant. The scheme dependence of the new coupling $\\widehat\\alpha_s$ is parameterized by a single parameter $C$, related to transformations of the QCD scale $\\Lambda$. It is demonstrated that appropriate choices of $C$ can lead to substantial improvements in the perturbative prediction of physical observables. As phenomenological applications, we study $e^+e^-$ scattering and decays of the $\\tau$ lepton into hadrons, both being governed by the QCD Adler function.

  20. CAP Reform and the Doha Development Agenda

    NARCIS (Netherlands)

    van Dijck, P.; Faber, G.

    2004-01-01

    The CAP reforms that the EU accepted in June 2003 will partially decouple direct income payments to farmers from production and make these payments conditional on cross-compliance. The reforms are driven by enlargement of EU membership, budgetary constraints, mounting pressures from diverse animal w

  1. The Effectiveness of Caps on Political Lobbying

    NARCIS (Netherlands)

    Matejka, M.; Onderstal, A.M.; De Waegenaere, A.M.B.

    2002-01-01

    In this paper, we analyze a lobby game, modelled as an all-pay auction in which interest groups submit bids in order to obtain a political prize.The bids are restricted to be below a cap imposed by the government.For both an incomplete and a complete information setting we show the following results

  2. INTERNATIONAL WHEAT PRICE TRANSMISSION AND CAP REFORM

    OpenAIRE

    Thompson, Stanley R.; Bohl, Martin T.

    1999-01-01

    We illustrate how CAP policy reforms influence the transmission of world prices to domestic markets. Monthly wheat price data in Germany are used to obtain price transmission elasticities. Correctly accounting for structural breaks and the time series properties of the data yield transmission elasticities that differ dramatically among policy regimes.

  3. Knowledge Management at Cap Gemini Nederland

    NARCIS (Netherlands)

    M.J. Vlaanderen (Marie Jose)

    1998-01-01

    textabstractThe theme of this paper is knowledge management (KM) at an organization that provides information technology (IT) services. It is based on the results of a KM-survey of the Finance Division of Cap Gemini (CG) conducted during the spring of 1997.

  4. ATLAS: End-cap Toroid assembly

    CERN Multimedia

    2006-01-01

    In building 191 and building 180- assembly of this massive piece.To reach the top of the end-cap the cranes has to be used and during the assembly you can see welding and hear many tools running background.

  5. Emission of alpha particles and other light nuclei as a fission process

    International Nuclear Information System (INIS)

    The fission theory was successfully applied to the emission of alpha particles and other light nuclei from a heavy nucleus. Good agreement (within +-0.8 orders of magnitude) of the theoretical life times with experimental ones over a range of 24 orders of magnitude, was obtained. Three macroscopic models have been extended for the nuclear systems with different charge densities. A phenomenological shell correction was introduced. WKB approximation was used. By taking into account the nuclear deformation, the life-time of the alpha decay from a shape isomeric state was predicted. A new semiempirical relationship for the alpha decay life-time was derived. (author)

  6. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  7. Inclusive J/\\psi Production In \\Upsilon Decay Via Color-singlet Mechanism

    CERN Document Server

    He, Zhi-Guo

    2009-01-01

    We reconsider the tree level color-singlet contribution for the inclusive J/\\psi production in \\Upsilon decay with the \\alpha_{s}^{5} order QCD process \\Upsilon\\to J/\\psi+c\\bar{c}+g and \\alpha^{2}\\alpha_s^{2} order QED processes \\Upsilon\\to\\gamma^{\\ast}\\to J/\\psi+c\\bar{c} and \\Upsilon\\to J/\\psi+gg. It is found that the contribution of the QED process is compatible with that of the QCD process, and the numerical results for the QCD process alone is an order of magnitude smaller than the previous theoretical predictions, and our theoretical prediction in total is about an order of magnitude smaller than the recent CLEO measurement on the branching fraction B(\\Upsilon\\to J/\\psi+X). It indicates that the J/\\psi production mechanism in \\Upsilon decay is not well understood, and further theoretical work and experimental analysis are still necessary.

  8. Neutron bound {beta}- decay- BOB

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, M.; Berger, M.; Emmerich, R.; Faestermann, T.; Gutsmiedl, E.; Hartmann, F.J.; Paul, S.; Ruschel, S.; Schoen, J.; Schott, W.; Schubert, U.; Trautner, A. [Physik-Department, TUM, 85748 Garching (Germany); Engels, R. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Fierlinger, P. [Excellence Cluster Universe, TUM, 85748 Garching (Germany); Hertenberger, R. [Sektion Physik, LMU, 85748 Garching (Germany); Roehrmoser, R. [FRM2, TUM, 85748 Garching (Germany); Udem, T. [Max-Planck-Institut fuer Quantenphysik, 85748 Garching (Germany)

    2011-07-01

    The bound neutron {beta}-decay(BOB) into a hydrogen atom and an electron antineutrino is investigated.The hyper-fine-state population of the monoenergetic hydrogen atoms (326.3 eV) yields the neutrino left-handed-ness or a possible right-handed admixture and possible small scalar and tensor contributions to the weak force. Preexperiments to measure the BOB H(2s) atoms have been done or are being set up using ionizer and RF discharge proton sources, a Wien filter, Cs and Ar cells, a spin filter, electric counter and accelerating fields, a double focusing magnet and a solar blind PM for the Lyman-{alpha} photons. In a first experiment, the charge exchange of the H(2s) atoms into H{sup -}, offering a selective method to discriminate these states against background, is investigated. In a second step the number of background H(2s) resulting from protons interacting with the walls of the experimental setup are determined. For this a quenching E field and a solar blind PM are used.

  9. Targeted Alpha Therapy: From Alpha to Omega

    International Nuclear Information System (INIS)

    This review covers the broad spectrum of Targeted Alpha Therapy (TAT) research in Australia; from in vitro and in vivo studies to clinical trials. The principle of tumour anti-vascular alpha therapy (TAVAT) is discussed in terms of its validation by Monte Carlo calculations of vascular models and the potential role of biological dosimetry is examined. Summmary of this review is as follows: 1. The essence of TAT 2. Therapeutic objectives 3. TAVAT and Monte Carlo microdosimetry 4. Biological dosimetry 5. Preclinical studies 6. Clinical trials 7. What next? 8. Obstacles. (author)

  10. Co-Decaying Dark Matter

    OpenAIRE

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-01-01

    We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross-section, which is predicted to be boosted, and the decay rate ...

  11. Structure, stability and folding of the alpha-helix.

    Science.gov (United States)

    Doig, A J; Andrew, C D; Cochran, D A; Hughes, E; Penel, S; Sun, J K; Stapley, B J; Clarke, D T; Jones, G R

    2001-01-01

    Pauling first described the alpha-helix nearly 50 years ago, yet new features of its structure continue to be discovered, using peptide model systems, site-directed mutagenesis, advances in theory, the expansion of the Protein Data Bank and new experimental techniques. Helical peptides in solution form a vast number of structures, including fully helical, fully coiled and partly helical. To interpret peptide results quantitatively it is essential to use a helix/coil model that includes the stabilities of all these conformations. Our models now include terms for helix interiors, capping, side-chain interactions, N-termini and 3(10)-helices. The first three amino acids in a helix (N1, N2 and N3) and the preceding N-cap are unique, as their amide NH groups do not participate in backbone hydrogen bonding. We surveyed their structures in proteins and measured their amino acid preferences. The results are predominantly rationalized by hydrogen bonding to the free NH groups. Stabilizing side-chain-side-chain energies, including hydrophobic interactions, hydrogen bonding and polar/non-polar interactions, were measured accurately in helical peptides. Helices in proteins show a preference for having approximately an integral number of turns so that their N- and C-caps lie on the same side. There are also strong periodic trends in the likelihood of terminating a helix with a Schellman or alpha L C-cap motif. The kinetics of alpha-helix folding have been studied with stopped-flow deep ultraviolet circular dichroism using synchrotron radiation as the light source; this gives a far superior signal-to-noise ratio than a conventional instrument. We find that poly(Glu), poly(Lys) and alanine-based peptides fold in milliseconds, with longer peptides showing a transient overshoot in helix content.

  12. Facially amphiphilic thiol capped gold and silver nanoparticles

    OpenAIRE

    Bhat, Shreedhar; Maitra, Uday

    2008-01-01

    A series of bile acid-derived facially amphiphilic thiols have been used to cap sliver and gold nanoparticles. The self-assembling properties of these steroid-capped nanoparticles have been investigated and reported in this article.

  13. Facially amphiphilic thiol capped gold and silver nanoparticles

    Indian Academy of Sciences (India)

    Shreedhar Bhata; Uday Maitra

    2008-11-01

    A series of bile acid-derived facially amphiphilic thiols have been used to cap sliver and gold nanoparticles. The self-assembling properties of these steroid-capped nanoparticles have been investigated and reported in this article.

  14. Simulation of 125I induced DNA strand breaks in a CAP-DNA complex

    International Nuclear Information System (INIS)

    The E. coli catabolite gene activator protein (CAP)-DNA complex with 125I located at the position of the H5 atom of the cytosine near the centre was incorporated into the PARTRAC track structure code. DNA strand breaks due to irradiation were calculated by track structure and radical attack simulations: strand breaks due to neutralisation of the highly charged 125Te ion were derived from a semi-empirical distribution. According to the calculations, the neutralisation effect dominates the strand breakage frequency at 2 bases away from the 125I decay site on both strands. The first breakage distribution counted from a 32P labelled end on the strand with 125I agreed well with experimental data, but on the opposite strand, the calculated distribution is more concentrated around the decay site and its yield is about 20% larger than the measured data. (author)

  15. Cytochrome c-Capped Fluorescent Gold Nanoclusters: Imaging of Live Cells and Delivery of Cytochrome c.

    Science.gov (United States)

    Chattoraj, Shyamtanu; Amin, Md Asif; Bhattacharyya, Kankan

    2016-07-01

    Cytochrome c-capped fluorescent gold nanoclusters (Au-NCs) are used for imaging of live lung and breast cells. Delivery of cytochrome c inside the cells is confirmed by covalently attaching a fluorophore (Alexa Fluor 594) to cytochrome c-capped Au-NCs and observing fluorescence from Alexa 594 inside the cell. Mass spectrometry studies suggest that in bulk water, addition of glutathione (GSH) to cytochrome c-capped Au-NCs results in the formation of glutathione-capped Au-NCs and free apo-cytochrome c. Thus glutathione displaces cytochrome c as a capping agent. Using confocal microscopy, the emission spectra and decay of Au-NCs are measured in live cells. From the position of the emission maximum it is shown that the Au-NCs exist as Au8 in bulk water and as Au13 inside the cells. Fluorescence resonance energy transfer from cytochrome c-Au-NC (donor) to Mitotracker Orange (acceptor) indicates that the Au-NCs localise in the mitochondria of live cells. PMID:27028215

  16. Buffett’s Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting...

  17. Exploring plasmonic coupling in hole-cap arrays

    OpenAIRE

    Schmidt, Thomas M.; Maj Frederiksen; Vladimir Bochenkov; Sutherland, Duncan S

    2015-01-01

    The plasmonic coupling between gold caps and holes in thin films was investigated experimentally and through finite-difference time-domain (FDTD) calculations. Sparse colloidal lithography combined with a novel thermal treatment was used to control the vertical spacing between caps and hole arrays and compared to separated arrays of holes or caps. Optical spectroscopy and FDTD simulations reveal strong coupling between the gold caps and both Bloch Wave-surface plasmon polariton (BW-SPP) modes...

  18. Nuclear decay by emission of charged particle-superasymmetric fission process

    International Nuclear Information System (INIS)

    The macro-microscopic method, adapted for superasymmetric fission was applied to the alpha decay and other kinds of charged particles emission which are possible due to the nuclear shell structure. Three macroscopic models (the liquid drop model, the finite range of nuclear forces model and the Yukawa exponential model) are extended for nuclear systems with different charge densities. Various numerical methods for the computation of Coulomb and surface energy of a general shape nucleus are presented along with analytical results for some particular shapes. A phenomenological correction was used to obtain the experimental Q-value. This formalism was applied to the alpha decay from the ground state and from a fission isomeric state. A time dependent Hartree-Fock method is used to estimate the zero vibration energy. A new semiempirical formula giving the best estimates for the alpha decay lifetimes was derived and used to predict new alpha emitters. For this new mode of decay intermediate between alpha decay and the traditional fission, larger probabilities are obtained for the combinations of parent-nucleus-heavy cluster leading to a magic daughter nuclei or not too far from it

  19. Democratic decay of 6Be exposed by correlations

    CERN Document Server

    Egorova, I A; Grigorenko, L V; Chajecki, Z; Coupland, D; Elson, J M; Ghosh, T K; Howard, M E; Iwasaki, H; Kilburn, M; Lee, Jenny; Lynch, W G; Manfredi, J; Marley, S T; Sanetullaev, A; Shane, R; Shetty, D V; Sobotka, L G; Tsang, M B; Winkelbauer, J; Wuosmaa, A H; Youngs, M; Zhukov, M V

    2012-01-01

    The interaction of an E/A=70-MeV 7Be beam with a Be target was used to populate levels in 6Be following neutron knockout reactions. The three-body decay of the ground and first excited states into the alpha+p+p exit channel were detected in the High Resolution Array (HiRA). Precise three-body correlations extracted from the experimental data allowed us to obtain an insight into the mechanism of the three-body democratic decay. The correlation data are in a nice agreement with a three-cluster-model calculation and thus validate this theoretical approach over a broad energy range.

  20. Supersymmetric top quark decays

    International Nuclear Information System (INIS)

    The supersymmetric decays of the top quark into charged Higgs plus bottom, t → H+b, and into the supersymmetric partner of the top (u1) plus the lightest neutralino (χ10), t → u1χ10, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of the gauge group SU(2) x U(1). The possibility of detecting these decays at present, i.e. given the available bounds on supersymmetric parameters, is compared with the situation a Next e+e- Linear Collider would face if supersymmetric particles were still undiscovered at LEP II. The indirect implications for t → H+b and t → u1χ10 of a measurement of the bottom quark decay b → sγ at the Standard Model level are taken into account. (orig.)

  1. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → 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 B0 → D*- a{sub 0}+ 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 10-6. 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 γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  2. Alpha-particle diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Young, K.M.

    1991-01-01

    This paper will focus on the state of development of diagnostics which are expected to provide the information needed for {alpha}- physics studies in the future. Conventional measurement of detailed temporal and spatial profiles of background plasma properties in DT will be essential for such aspects as determining heating effectiveness, shaping of the plasma profiles and effects of MHD, but will not be addressed here. This paper will address (1) the measurement of the neutron source, and hence {alpha}-particle birth profile, (2) measurement of the escaping {alpha}-particles and (3) measurement of the confined {alpha}-particles over their full energy range. There will also be a brief discussion of (4) the concerns about instabilities being generated by {alpha}-particles and the methods necessary for measuring these effects. 51 refs., 10 figs.

  3. Imaging alpha particle detector

    Science.gov (United States)

    Anderson, D.F.

    1980-10-29

    A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  4. Electronic key system using alpha detection

    International Nuclear Information System (INIS)

    We have developed the new electronic key system utilizes random pulse from alpha-particle detection with PIN photo diode. The random pulse by natural decay of alpha source is stable under the every outside environment like as temperature, pressure, an electromagnetic wave, and so on. The stable and un-predicted signals of the random pulses are the most suitable as a source of authentication signal for the electric key system. The program made of manufacture side forms the key code under current electronic key. Therefore, the manufacture must keep the code data secret for long time. The new electronic key always identify between key body and each key by the original pulse data from alpha particles. It is reduce the control cost of security remarkably. Moreover, back ground noise can be ignored in the circuit and it doesn't need to enlarge a total number of activity. The activity of the alpha source is about 10-100 Bq in one module. (author)

  5. CMS end-cap yoke at the detector's assembly site.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    The magnetic flux generated by the superconducting coil in the CMS detector is returned via an iron yoke comprising three end-cap discs at each end (end-cap yoke) and five concentric cylinders (barrel yoke). This picture shows the first of three end-cap discs (red) seen through the outer cylinder of the vacuum tank which will house the superconducting coil.

  6. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  7. Fast Proton Decay

    OpenAIRE

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

    2009-01-01

    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 mos...

  8. Greening CAP payments: a missed opportunity?

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Alan

    2013-01-15

    At an important point in the current reform of the Common Agricultural Policy (CAP), a new IIEA policy brief by Professor Alan Matthews, one of the EU’s foremost experts on the topic, considers proposals to green direct farm payments. Professor Matthews argues that proposed greening of direct payments – the key innovation in the current round of CAP Reform – look likely to fail. While greening may survive as a concept, the likely outcome of the negotiations between Agriculture Ministers and the European Parliament will deliver little practical environmental benefit. The paper examines the rationale underpinning greening, arguing that it exists to justify the continuation of a large agricultural budget, explores reasons for the apparent failure of the proposals, and reflects on the implications for future efforts to better integrate environmental objectives into EU agriculture policy. This is the first in a series of Environment Nexus policy briefs by leading experts in the fields of agriculture, energy, climate change and water.

  9. Should we geoengineer larger ice caps?

    CERN Document Server

    Haqq-Misra, Jacob

    2015-01-01

    The climate of Earth is susceptible to catastrophes that could threaten the longevity of human civilization. Geoengineering to reduce incoming solar radiation has been suggested as a way to mediate the warming effects of contemporary climate change, but a geoengineering program for thousands of years could also be used to enlarge the size of the polar ice caps and create a permanently cooler climate. Such a large ice cap state would make Earth less susceptible to climate threats and could allow human civilization to survive further into the future than otherwise possible. Intentionally extending Earth's glacial coverage will require uninterrupted commitment to this program for millenia but would ultimately reach a cooler equilibrium state where geoengineering is no longer needed. Whether or not this program is ever attempted, this concept illustrates the need to identify preference among potential climate states to ensure the long-term success of civilization.

  10. Status of the AlCap experiment

    CERN Document Server

    Litchfield, R Phillip

    2015-01-01

    The AlCap experiment is a joint project between the COMET and Mu2e collaborations. Both experiments intend to look for the lepton-flavour violating conversion $\\mu + A \\rightarrow e + A$, using tertiary muons from high-power pulsed proton beams. In these experiments the products of ordinary muon capture in the muon stopping target are an important concern, both in terms of hit rates in tracking detectors and radiation damage to equipment. The goal of the AlCap experiment is to provide precision measurements of the products of nuclear capture on Aluminium, which is the favoured target material for both COMET and Mu2e. The results will be used for optimising the design of both conversion experiments, and as input to their simulations. Data was taken in December 2013 and is currently being analysed.

  11. ATLAS End-cap Part II

    CERN Multimedia

    2007-01-01

    The epic journey of the ATLAS magnets is drawing to an end. On Thursday 12 July, the second end-cap of the ATLAS toroid magnet was lowered into the cavern of the experiment with the same degree of precision as the first (see Bulletin No. 26/2007). This spectacular descent of the 240-tonne component, is one of the last transport to be completed for ATLAS.

  12. Polar cap size metrics study at CCMC

    Science.gov (United States)

    Rastaetter, L.; Kuznetsova, M. M.; Hesse, M.; Gombosi, T. I.; Raeder, J.; Weimer, D.

    2005-12-01

    The Community-Coordinated Modeling Center (CCMC) tests space physics models covering space from the Sun's corona to the Earth's ionosphere and makes them available for researchers through a run-on-request capability. The polar cap size and location as observed by global auroral imagers is used as a basis model to study the performance of global MHD simulation models and statistical models of the auroral ionosphere. With good confidence one can assume that auroral emissions are located within the closed magnetic field lines in a narrow region adjacent to the boundary of the open field line region of the polar cap. In this study we are using imager data from POLAR (FUV) for several events from 1997 to 2000 for which reasonable coverage is available. Simulation runs have been performed using the global magnetospheric models BATSRUS (T. Gombosi et al., U. Michigan) and OpenGGCM (J. Raeder, U. New Hampshire) as well as the Weimer (2000,2005) field-aligned current models (D. Weimer, Mission Research Corp.) fed with upstream solar wind data from the ACE or Geotail satellites. In addition to direct field line tracings available from the 3D MHD model outputs, we use field-aligned currents from both MHD models and the Weimer-2K model to determine the polar cap boundary by using the position of the maximum absolute FAC value in 16 local time sectors. We define skill scores that measure the agreement in the polar cap sizes and location between measurements and models as an example of implementations of metrics to track model performance and apply the analysis to a number of storm event days.

  13. Particle Entrainment in Spherical-Cap Wakes

    OpenAIRE

    Warncke, N.G.W.; Delfos, R.; Ooms, G.; Westerweel, J.

    2011-01-01

    In this work we study the preferential concentration of small particles in the turbulent wake behind a spherical-cap object. We present a model predicting the mean particle concentration in the near-wake as a function of the characteristic Stokes number of the problem, the turbulence level and the Froude number. We compare the model with our experimental results on this flow, measured in a vertical water tunnel.

  14. Translated origin spherical cap harmonic analysis

    OpenAIRE

    De Santis, A.; Istituto Nazionale di Geofisica, Roma, Italy

    1991-01-01

    The method of spherical cap harmonic analysis (SCHA), due to Haines (1985) is appropriate for regional geomagnetic field modelling as it includes the required potential field constraints and, for a given number of model parameters, describes shorter wavelength features than a global spherical harmonic model. If the origin of the coordinate system is moved from the centre of the Earth towards the surface then the Earth's surface is no longer equidistant from the origin. At the Earth's surface ...

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

    CERN Document Server

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

    2007-01-01

    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.

  16. Pulp-Capping with Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Peycheva Kalina

    2015-11-01

    Full Text Available There are two considerations for direct pulp capping - accidental mechanical pulp exposure and exposure caused by caries. Mineral trioxide aggregate (MTA was used as pulp-capping material to preserve the vitality of the pulpal tissues. Follow-up examinations revealed that treatment was successful in preserving pulpal vitality and continued development of the tooth. On the basis of available information, it appears that MTA is the material of choice for some clinical applications. Material and methods: Cases 18 - 8 teeth with grey MTA, 10 teeth with white MTA; diagnose: Pulpitis chronica ulcerosa, Electro pulpal test (EOD - 30-35 μA, pre-clinical X-ray - without changes in the structures, follow ups for 4 years. Successful treatments: without clinical symptoms and changes in the X-rays: 5 teeth with grey MTA, 8 teeth with white MTA for period of 4 years. Unsuccessful treatments: Clinical symptoms and sometimes changes in the X-ray: 3 with grey MTA, 2 with white MTA. MTA is an appropriate material for pulp-capping and follow-up examinations revealed that the treatment was successful in preserving pulpal vitality.

  17. The alpha channeling effect

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, N. J.

    2015-12-10

    Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled into useful energy, so as to heat fuel ions or to drive current. Such a channeling needs to be catalyzed by waves Waves can produce diffusion in energy of the alpha particles in a way that is strictly coupled to diffusion in space. If these diffusion paths in energy-position space point from high energy in the center to low energy on the periphery, then alpha particles will be cooled while forced to the periphery. The energy from the alpha particles is absorbed by the wave. The amplified wave can then heat ions or drive current. This process or paradigm for extracting alpha particle energy collisionlessly has been called alpha channeling. While the effect is speculative, the upside potential for economical fusion is immense. The paradigm also operates more generally in other contexts of magnetically confined plasma.

  18. Giant Dipole Resonance as a Fingerprint of $\\alpha$ Clustering Configurations in $^{12}$C and $^{16}$O

    CERN Document Server

    He, W B; Cao, X G; Cai, X Z; Zhang, G Q

    2014-01-01

    It is studied how the $\\alpha$ cluster degrees of freedom, such as $\\alpha$ clustering configurations close to the $\\alpha$ decay threshold in $^{12}$C and $^{16}$O, including the linear chain, triangle, square, kite, and tetrahedron, affect nuclear collective vibrations with a microscopic dynamical approach, which can describe properties of nuclear ground states well across the nuclide chart and reproduce the standard giant dipole resonance (GDR) of $^{16}$O quite nicely. It is found that the GDR spectrum is highly fragmented into several apparent peaks due to the $\\alpha$ structure. The different $\\alpha$ cluster configurations in $^{12}$C and $^{16}$O have corresponding characteristic spectra of GDR. The number and centroid energies of peaks in the GDR spectra can be reasonably explained by the geometrical and dynamical symmetries of $\\alpha$ clustering configurations. Therefore, the GDR can be regarded as a very effective probe to diagnose the different $\\alpha$ cluster configurations in light nuclei.

  19. Baryogenesis and proton decay

    International Nuclear Information System (INIS)

    The constraints are analyzed that proton decay experiments and cosmologically sound unification models impose on each other. An intermediate scale of around 1010 GeV arises from considerations on baryogenesis, inflation and supersymmetry breaking. An upper bound to the gravitino mass of about 50 TeV follows from current proton lifetime limits

  20. Hyperon Radiative Decay

    OpenAIRE

    Kaxiras, Efthimios; Soyeur, Madeleine; Moniz, Ernest J.

    1985-01-01

    The radiative decay widths of the low-lying strange baryons are calculated both within the relativistic quark bag model and the nonrelativistic potential model. These widths are found to depend sensitively upon the quark-model dynamics through multiplet mixing and q4¯q admixtures. The comparison between our calculated results and the very limited experimental data is discussed.

  1. Neutrinoless τ decays

    International Nuclear Information System (INIS)

    Lepton number and lepton flavor violation processes occur naturally in many extensions of the Standard Model. No evidence for such processes has been found so far. Recent searches for lepton number violating τ decays are reviewed within the context of the theoretical predictions

  2. Neutrinoless Double Beta Decay

    CERN Document Server

    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.

  3. Attention decay in science

    CERN Document Server

    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. Synthesis and characterization of TGA-capped CdTe nanoparticles embedded in PVA matrix

    International Nuclear Information System (INIS)

    This paper reports the synthesis and characterization of TGA-capped CdTe nanoparticles and its nanocomposite in a PVA matrix prepared by ex situ technique. The crystallite sizes of the CdTe nanoparticles and nanocomposite calculated from X-ray diffraction patterns are 6.07 and 7.75 nm with hexagonal structure, respectively. The spherical nature of the CdTe nanoparticles is confirmed from transmission electron microscopy measurements. Fourier transform infrared spectroscopy shows good interaction between the CdTe nanoparticles and PVA matrix. The absorption and emission spectra have also been studied. The stability of the TGA-capped CdTe nanoparticles increases after dispersion in a PVA matrix. In electrical measurements, the dark conductivity and the steady-state photoconductivity of CdTe nanocomposite thin films have been studied. The effect of temperature and intensity on the transient photoconductivity of CdTe nanocomposite is also studied. The values of differential life time have been calculated from the decay of photocurrent with time. The non-exponential decay of photoconductivity is observed indicating that the traps exist at all the energies in the band gap, making these materials suitable for various optoelectronic devices. (orig.)

  5. What Lies Below a Martian Ice Cap

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for larger annotated version This image (top) taken by the Shallow Radar instrument on NASA's Mars Reconnaissance Orbiter reveals the layers of ice, sand and dust that make up the north polar ice cap on Mars. It is the most detailed look to date at the insides of this ice cap. The colored map below the radar picture shows the topography of the corresponding Martian terrain (red and white represent higher ground, and green and yellow lower). The radar image reveals four never-before-seen thick layers of ice and dust separated by layers of nearly pure ice. According to scientists, these thick ice-free layers represent approximately one-million-year-long cycles of climate change on Mars caused by variations in the planet's tilted axis and its eccentric orbit around the sun. Adding up the entire stack of ice gives an estimated age for the north polar ice cap of about 4 million years a finding that agrees with previous theoretical estimates. The ice cap is about 2 kilometers (1.2 miles) thick. The radar picture also shows that the boundary between the ice layers and the surface of Mars underneath is relatively flat (bottom white line on the right). This implies that the surface of Mars is not sagging, or bending, under the weight of the ice cap and this, in turn, suggests that the planet's lithosphere, a combination of the crust and the strong parts of the upper mantle, is thicker than previously thought. A thicker lithosphere on Mars means that temperatures increase more gradually with depth toward the interior. Temperatures warm enough for water to be liquid are therefore deeper than previously thought. Likewise, if liquid water does exist in aquifers below the surface of Mars, and if there are any organisms living in that water, they would have to be located deeper in the planet. The topography data are from Mars Orbiter Laser Altimeter, which was flown on NASA's Mars Global Surveyor mission. NPLD stands

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

    OpenAIRE

    Gates, J. M.

    2008-01-01

    Isotopes of rutherfordium (258-261Rf) were produced in irradiations of 238U targets with 26Mg beams. Excitation functions were measured for the 4n, 5n and 6n exit channels. Production of 261Rf in the 3n exit channel with a cross section of 28+92-26 pb was observed. Alpha decay of 258Rf 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 259Rf, the electron capture/total decay branching ratio was measured t...

  7. Greenhouse gas emissions through cap barriers of landfills

    Energy Technology Data Exchange (ETDEWEB)

    Gourc, J.P.; Staub, M.; Simonin, R. [Grenoble Univ. (France). LTHE

    2009-07-01

    A study was conducted to examine the environmental impacts of landfill cap covers used to produce biogas. The sensitivity of the environmental performance of landfills on biogas collection and recovery systems as well as on cap cover characteristics was investigated. The study examined both soil and geosynthetic landfill cap covers used to maintain impermeability at landfill sites as well as to enable biogas recovery. Two types of cap cover were discussed: (1) a cover that enabled passive wetting of the landfill wastes through rainfall; and (2) an impermeable cap used to control leachate recirculation. The environmental impacts of both caps were discussed. The study showed that landfill cap covers are a significant means of sequestering greenhouse gases (GHGs).

  8. Energy of W distribution in top quark decays

    OpenAIRE

    Jeżabek, M.; Jünger, C.

    1993-01-01

    A relatively simple analytical formula is derived for the energy spectrum of $W$ boson in top quark decays $t\\to Wb$ including ${\\cal O}(\\alpha_s)$ radiative corrections. We discuss the accuracy of this formula and compare it to a more general albeit more complicated one derived in \\cite{CJK}~. A Monte Carlo algorithm for generation of $W$ energy spectrum is briefly described.

  9. Synthesis of N-hydroxycinnamides capped with a naturally occurring moiety as inhibitors of histone deacetylase.

    Science.gov (United States)

    Huang, Wei-Jan; Chen, Ching-Chow; Chao, Shi-Wei; Lee, Shoei-Sheng; Hsu, Fen-Lin; Lu, Yeh-Lin; Hung, Ming-Fang; Chang, Chung-I

    2010-04-01

    Histone deacetylase (HDAC) inhibitors are regarded as promising therapeutics for the treatment of cancer. All reported HDAC inhibitors contain three pharmacophoric features: a zinc-chelating group, a hydrophobic linker, and a hydrophobic cap for surface recognition. In this study we investigated the effectiveness of osthole, a hydrophobic Chinese herbal compound, as the surface recognition cap in hydroxamate-based compounds as inhibitors of HDAC. Nine novel osthole-based N-hydroxycinnamides were synthesized and screened for enzyme inhibition activity. Compounds 9 d, 9 e, 9 g exhibited inhibitory activities (IC(50)=24.5, 20.0, 19.6 nM) against nuclear HDACs in HeLa cells comparable to that of suberoylanilide hydroxamic acid (SAHA; IC(50)=24.5 nM), a potent inhibitor clinically used for the treatment of cutaneous T-cell lymphoma (CTCL). While compounds 9 d and 9 e showed SAHA-like activity towards HDAC1 and HDAC6, compound 9 g was more selective for HDAC1. Compound 9 d exhibited the best cellular effect, which was comparable to that of SAHA, of enhancing acetylation of either alpha-tubulin or histone H3. Molecular docking analysis showed that the osthole moiety of compound 9 d may interact with the same hydrophobic surface pocket exploited by SAHA and it may be modified to provide class-specific selectivity. These results suggest that osthole is an effective hydrophobic cap when incorporated into N-hydroxycinnamide-derived HDAC inhibitors. PMID:20209563

  10. Local versus nonlocal $\\alpha\\alpha$ interactions in $3\\alpha$ description of $^{12}$C

    CERN Document Server

    Suzuki, Y; Descouvemont, P; Fujiwara, Y; Matsumura, H; Orabi, M; Theeten, M

    2008-01-01

    Local $\\alpha \\alpha$ potentials fail to describe $^{12}$C as a $3\\alpha$ system. Nonlocal $\\alpha \\alpha$ potentials that renormalize the energy-dependent kernel of the resonating group method allow interpreting simultaneously the ground state and $0^+_2$ resonance of $^{12}$C as $3\\alpha$ states. A comparison with fully microscopic calculations provides a measure of the importance of three-cluster exchanges in those states.

  11. Characterization of cap binding proteins associated with the nucleus

    International Nuclear Information System (INIS)

    Eucaryotic mRNAs a carry 7-methylguanosine triphosphate residue (called cap structure) at their 5' terminus. The cap plays an important role in RNA recognition. Cap binding proteins (CBP) of HeLa cells were identified by photoaffinity labelling using the cap analogue γ-(32P)-(4-(benzoyl-phenyl)methylamido)-7-methylguanosine-5'-triphosphate (BP-m7GTP). Photoreaction of this cap analogue with HeLa cell initiation factors resulted in specific labelling of two polypeptides of Msub(r) 37000 and 26000. The latter was also labelled in crude initiation factors prepared from reticulocytes and is identical to the cap binding protein CBP I previously identified. These cap binding proteins were also affinity labelled in poliovirus infected cell extracts. Photoaffinity reaction with BP-m7GTP of whole HeLa cell homogenate showed three additional polypeptides with Msub(r) 120000, 89000 and 80000. These cap binding proteins were found to be associated with the nucleus and are therefore referred to as nuclear cap binding proteins, i.e. NCBP 1, NCBP 2 and NCBP 3. They were also present in splicing extracts. Photoaffinity labelling in these nuclear extracts was differentially inhibited by various cap analogues and capped mRNAs. Affinity chromatography on immobilized globin mRNA led to a partial separation of the three nuclear cap binding proteins. Chromatography on m7GTP-Sepharose resulted in a specific binding of NCBP 3. The different behaviour of the cap binding proteins suggests that they are functionally distinct and that they might be involved in different processes requiring cap recognition. (Author)

  12. Rare B decays at LEP

    CERN Document Server

    Kluit, P M

    2001-01-01

    The results of the LEP experiments for rare B decays will be reviewed, covering hadronic final states, radiative and other rare decays and results for the inclusive charmless branching ratio. (8 refs).

  13. Cold atmospheric plasma (CAP changes gene expression of key molecules of the wound healing machinery and improves wound healing in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Stephanie Arndt

    Full Text Available Cold atmospheric plasma (CAP has the potential to interact with tissue or cells leading to fast, painless and efficient disinfection and furthermore has positive effects on wound healing and tissue regeneration. For clinical implementation it is necessary to examine how CAP improves wound healing and which molecular changes occur after the CAP treatment. In the present study we used the second generation MicroPlaSter ß® in analogy to the current clinical standard (2 min treatment time in order to determine molecular changes induced by CAP using in vitro cell culture studies with human fibroblasts and an in vivo mouse skin wound healing model. Our in vitro analysis revealed that the CAP treatment induces the expression of important key genes crucial for the wound healing response like IL-6, IL-8, MCP-1, TGF-ß1, TGF-ß2, and promotes the production of collagen type I and alpha-SMA. Scratch wound healing assays showed improved cell migration, whereas cell proliferation analyzed by XTT method, and the apoptotic machinery analyzed by protein array technology, was not altered by CAP in dermal fibroblasts. An in vivo wound healing model confirmed that the CAP treatment affects above mentioned genes involved in wound healing, tissue injury and repair. Additionally, we observed that the CAP treatment improves wound healing in mice, no relevant side effects were detected. We suggest that improved wound healing might be due to the activation of a specified panel of cytokines and growth factors by CAP. In summary, our in vitro human and in vivo animal data suggest that the 2 min treatment with the MicroPlaSter ß® is an effective technique for activating wound healing relevant molecules in dermal fibroblasts leading to improved wound healing, whereas the mechanisms which contribute to these observed effects have to be further investigated.

  14. Cold atmospheric plasma (CAP) changes gene expression of key molecules of the wound healing machinery and improves wound healing in vitro and in vivo.

    Science.gov (United States)

    Arndt, Stephanie; Unger, Petra; Wacker, Eva; Shimizu, Tetsuji; Heinlin, Julia; Li, Yang-Fang; Thomas, Hubertus M; Morfill, Gregor E; Zimmermann, Julia L; Bosserhoff, Anja-Katrin; Karrer, Sigrid

    2013-01-01

    Cold atmospheric plasma (CAP) has the potential to interact with tissue or cells leading to fast, painless and efficient disinfection and furthermore has positive effects on wound healing and tissue regeneration. For clinical implementation it is necessary to examine how CAP improves wound healing and which molecular changes occur after the CAP treatment. In the present study we used the second generation MicroPlaSter ß® in analogy to the current clinical standard (2 min treatment time) in order to determine molecular changes induced by CAP using in vitro cell culture studies with human fibroblasts and an in vivo mouse skin wound healing model. Our in vitro analysis revealed that the CAP treatment induces the expression of important key genes crucial for the wound healing response like IL-6, IL-8, MCP-1, TGF-ß1, TGF-ß2, and promotes the production of collagen type I and alpha-SMA. Scratch wound healing assays showed improved cell migration, whereas cell proliferation analyzed by XTT method, and the apoptotic machinery analyzed by protein array technology, was not altered by CAP in dermal fibroblasts. An in vivo wound healing model confirmed that the CAP treatment affects above mentioned genes involved in wound healing, tissue injury and repair. Additionally, we observed that the CAP treatment improves wound healing in mice, no relevant side effects were detected. We suggest that improved wound healing might be due to the activation of a specified panel of cytokines and growth factors by CAP. In summary, our in vitro human and in vivo animal data suggest that the 2 min treatment with the MicroPlaSter ß® is an effective technique for activating wound healing relevant molecules in dermal fibroblasts leading to improved wound healing, whereas the mechanisms which contribute to these observed effects have to be further investigated.

  15. CP-violations in decays

    Indian Academy of Sciences (India)

    Y Sakai

    2006-11-01

    Recent results on CP-violation measurements in decays from energy asymmetric -factory experiments are reported. Thanks to large accumulated data samples, CP-violations in decays in mixing-decay interference and direct CP-violation are now firmly established. The measurements of three angles of the unitarity triangle from CP-violations of decays are quite consistent with the Standard Model expectations. These results strongly support the validity of the Kobayashi-Maskawa prescription of CP-violation.

  16. Rare Down Quark Decays

    Science.gov (United States)

    Tung, Kwong-Kwai Humphrey

    1992-01-01

    The rare decays bto sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the bto sgamma and bto s+gluon dipole operators. In this thesis, the problem is investigated by considering the contributions of the epsilon -scalar field and the epsilon -dimensional operators that distinguish between the two methods. The discrepancies are shown to come from the epsilon-dimensional four-quark operators in dimensional reduction and not from the epsilon -scalar field. In the decay bto sl^+l^ -, the intermediate of cc pairs in the charm-penguin diagram can form the resonance states J/psi and psi^'. In the published literature, there is a sign discrepancy in the Breit-Wigner amplitude for the resonance effects. Here, the sign difference is settled by considering the unitarity limit of the amplitude in the Argand diagram. The effects of the resonances are quite substantial on the invariant mass spectrum for this decay. However, they are shown to be negligible on the dilepton energy spectrum below 0.95 GeV. The energy spectrum is, thus, more useful than the invariant mass spectrum for measurements of the top -quark mass. The decays Bto K^*X are well modeled by the quark-level decays bto sX. In the quark model, the hadronization is done using a nonrelativistic wave function. In the decay B to K^*gamma, the large K ^* recoil creates an uncertainty in calculating the branching ratio using the quark model. The problem is explored by considering other meson processes where data exist. The data on the pi form factor and the omegapi^0 transition form factor suggest the necessity to retain relativistic spinor and meson normalizations in the quark -model; however, the data do not resolve the

  17. ALPHA-2: the sequel

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    While many experiments are methodically planning for intense works over the long shutdown, there is one experiment that is already working at full steam: ALPHA-2. Its final components arrived last month and will completely replace the previous ALPHA set-up. Unlike its predecessor, this next generation experiment has been specifically designed to measure the properties of antimatter.   The ALPHA team lower the new superconducting solenoid magnet into place. The ALPHA collaboration is working at full speed to complete the ALPHA-2 set-up for mid-November – this will give them a few weeks of running before the AD shutdown on 17 December. “We really want to get some experience with this device this year so that, if we need to make any changes, we will have time during the long shutdown in which to make them,” says Jeffrey Hangst, ALPHA spokesperson. “Rather than starting the 2014 run in the commissioning stage, we will be up and running from the get go.&...

  18. On the Analytic Estimation of Radioactive Contamination from Degraded Alphas

    CERN Document Server

    Kadel, Richard W

    2016-01-01

    The high energy spectrum of alpha particles emitted from a single isotope uniformly contaminating a bulk solid has a flat energy spectrum with a high end cutoff energy equal to the maximal alpha kinetic energy ($T_{\\alpha}$) of the decay. In this flat region of the spectrum, we show the surface rate $r_b\\text{\\,(Bq/keV-cm}^{2})$ arising from a bulk alpha contamination $\\rho_b$ (Bq/cm$^3$) from a single isotope is given by $r_b =\\rho_b \\Delta R/ 4 \\Delta E $, where $\\Delta E = E_1-E_2>0\\ $ is the energy interval considered (keV) in the flat region of the spectrum and $\\Delta R = R_2-R_1$, where $R_2$ ($R_1$) is the amount of the bulk material (cm) necessary to degrade the energy of the alpha from $T_{\\alpha}$ to $E_2$ ($E_1$). We compare our calculation to a rate measurement of alphas from $^{147}$Sm, ($15.32\\%\\,\\pm\\,0.03\\%$ of Sm($nat$) and half life of $(1.06\\,\\pm\\,0.01)\\times\\,10^{11} \\text{yr}$, and find good agreement, with the ratio between prediction to measurement of $100.2\\%\\pm 1.6\\%\\,\\text{(stat)}\\pm...

  19. Structural and decay properties of $Z=132,138$ superheavy nuclei

    CERN Document Server

    Rather, Asloob A; Usmani, A A; Kumar, Bharat; Patra, S K

    2016-01-01

    In this paper, we analyze the structural properties of $Z=132$ and $Z=138$ superheavy nuclei within the ambit of axially deformed relativistic mean-field framework with NL$3^{*}$ parametrization and calculate the total binding energies, radii, quadrupole deformation parameter, separation energies, density distributions. We also investigate the phenomenon of shape coexistence by performing the calculations for prolate, oblate and spherical configurations. For clear presentation of nucleon distributions, the two-dimensional contour representation of individual nucleon density and total matter density has been made. Further, a competition between possible decay modes such as $\\alpha$-decay, $\\beta$-decay and spontaneous fission of the isotopic chain of superheavy nuclei with $Z=132$ within the range 312 $\\le$ A $\\le$ 392 and 318 $\\le$ A $\\le$ 398 for $Z=138$ is systematically analyzed within self-consistent relativistic mean field model. From our analysis, we inferred that the $\\alpha$-decay and spontaneous fiss...

  20. Further limit on 3α decay of Hoyle state

    Directory of Open Access Journals (Sweden)

    Rana T. K.

    2014-03-01

    Full Text Available The quantitative contributions of various direct three alpha decay mechanisms in the decay of the famous Hoyle state, the 02+ resonant excited state of 12C at excitation energy of 7.65 MeV, has been estimated using 60 MeV α inelastic scattering on 12C target in complete kinematical measurement. Simultaneous optimisation of three different distributions (the relative energy of 8Be like pairs, the root mean square energy deviation and the radial projection of symmetric Dalitz plot derived from the experimental data with those generated from the Monte Carlo simulated event sets, have been done to arrive at a consistent estimation of the contributions of various direct decay modes.

  1. Taxon interactions control the distributions of cryoconite bacteria colonizing a High Arctic ice cap.

    Science.gov (United States)

    Gokul, Jarishma K; Hodson, Andrew J; Saetnan, Eli R; Irvine-Fynn, Tristram D L; Westall, Philippa J; Detheridge, Andrew P; Takeuchi, Nozomu; Bussell, Jennifer; Mur, Luis A J; Edwards, Arwyn

    2016-08-01

    Microbial colonization of glacial ice surfaces incurs feedbacks which affect the melting rate of the ice surface. Ecosystems formed as microbe-mineral aggregates termed cryoconite locally reduce ice surface albedo and represent foci of biodiversity and biogeochemical cycling. Consequently, greater understanding the ecological processes in the formation of functional cryoconite ecosystems upon glacier surfaces is sought. Here, we present the first bacterial biogeography of an ice cap, evaluating the respective roles of dispersal, environmental and biotic filtration occurring at local scales in the assembly of cryoconite microbiota. 16S rRNA gene amplicon semiconductor sequencing of cryoconite colonizing a Svalbard ice cap coupled with digital elevation modelling of physical parameters reveals the bacterial community is dominated by a ubiquitous core of generalist taxa, with evidence for a moderate pairwise distance-decay relationship. While geographic position and melt season duration are prominent among environmental predictors of community structure, the core population of taxa appears highly influential in structuring the bacterial community. Taxon co-occurrence network analysis reveals a highly modular community structured by positive interactions with bottleneck taxa, predominantly Actinobacteria affiliated to isolates from soil humus. In contrast, the filamentous cyanobacterial taxon (assigned to Leptolyngbya/Phormidesmis pristleyi) which dominates the community and binds together granular cryoconite are poorly connected to other taxa. While our study targeted one ice cap, the prominent role of generalist core taxa with close environmental relatives across the global cryosphere indicate discrete roles for cosmopolitan Actinobacteria and Cyanobacteria as respective keystone taxa and ecosystem engineers of cryoconite ecosystems colonizing ice caps. PMID:27261672

  2. Resting alpha activity predicts learning ability in alpha neurofeedback

    OpenAIRE

    Wenya eNan; Feng eWan; Mang I eVai; Agostinho eRosa

    2014-01-01

    Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the tr...

  3. Non-leptonic decays of charmed and beautiful particles

    Energy Technology Data Exchange (ETDEWEB)

    Buccella, F.; Forte, M. (Naples Univ. (Italy). Ist. di Fisica Teorica); Miele, G. (Naples Univ. (Italy). Dipt. di Scienze Fisiche Istituto Nazionale di Fisica Nucleare, Naples (Italy)); Ricciardi, G. (Scuola Normale Superiore, Pisa (Italy) Istituto Nazionale di Fisica Nucleare, Pisa (Italy))

    1990-09-01

    By fitting simultaneously the values of {xi}=1/N{sub c} and {alpha}{sub s}(m{sub c}{sup 2}) on the inclusive rates of the Cabibbo allowed decays D, F{yields}PP and D{yields}PV, which are independent of the final state interactions, we find {xi}=0 and {alpha}{sub s}(m{sub c}{sup 2})=0.44. In order to explain the rescattering of the final states produced in the non-leptonic decays of charmed D-particles and to make theoretical predictions for all the exclusive channels, we propose a rescattering model based on the production of resonances in SU(3)-symmetry. In the PP sector we predict a new multiplet of meson resonances 0{sup +} which allows us with few free parameters, to obtain a satisfactory agreement between theoretical predictions and experimental data. Unfortunately, such an agreement cannot be obtained in the PV sector, for which the presence of other rescattering effects is needed to balance the exotic channel D{sup +}{yields}PV. In the PV sector we do not use any free parameter. Finally, we also make predicitions for the Cabibbo allowed decay channels B{yields}PP, PV, without considering in this case the final state interactions, because of the high energy of the decay products. (orig.).

  4. Electroweak penguin B decays

    CERN Document Server

    Nikodem, Thomas

    2016-01-01

    Flavour Changing Neutral Currents (FCNC) are sensitive probes for physics beyond the Standard Model (SM), so-called New Physics. An example of a FCNC is the $b \\to s$ quark transition described by the electroweak penguin Feynman diagram shown in Figure 1. In the SM such FCNC are only allowed with a loop structure (as e:g: shown in the figure) and not by tree level processes. In the loops heavy particles appear virtually and do not need to be on shell. Therefore also not yet discovered heavy particles with up to a mass $\\mathcal{O}$(TeV) could virtually contribute significantly to observables. Several recent measurements of electroweak penguin B decays exhibit interesting tensions with SM predictions, most prominently in the angular observable $P'_5$ 5 of the decay $B^0 \\to K^{*0} \\mu^+ \\mu^1$[1], which triggered a lot of discussion in the theory community [2]-[14].

  5. Decay constants in geochronology

    Institute of Scientific and Technical Information of China (English)

    IgorM.Villa; PaulR.Renne

    2005-01-01

    Geologic time is fundamental to the Earth Sciences, and progress in many disciplines depends critically on our ability to measure time with increasing accuracy and precision. Isotopic geochronology makes use of the decay of radioactive nuclides as a help to quantify the histories of rock, minerals, and other materials. Both accuracy and precision of radioisotopic ages are, at present, limited by those of radioactive decay constants. Modem mass spectrometers can measure isotope ratios with a precision of 10-4 or better. On the other hand, the uncertainties associated with direct half-life determinations are, in most cases, still at the percent level. The present short note briefly summarizes progress and problems that have been encountered during the Working Group's activity.

  6. Decay of Hoyle state

    Indian Academy of Sciences (India)

    S Bhattacharya; T K Rana; C Bhattacharya; S Kundu; K Banerjee; T K Ghosh; G Mukherjee; R Pandey; P Roy

    2014-11-01

    The prediction of Hoyle state was necessitated to explain the abundance of carbon, which is crucial for the existence of life on Earth and is the stepping stone for understanding the abundance of other heavier elements. After the experimental confirmation of its existence, soon it was realized that the Hoyle state was `different’ from other excited states of carbon, which led to intense theoretical and experimental activities over the past few decades to understand its structure. In recent times, precision, high statistics experiments on the decay of Hoyle state have been performed at the Variable Energy Cyclotron Centre, to determine the quantitative contributions of various direct 3 decay mechanisms of the Hoyle state. The present results have been critically compared with those obtained in other recent experiments and their implications have been discussed.

  7. Rare b decays

    Energy Technology Data Exchange (ETDEWEB)

    Tung, K.K.H.

    1992-01-01

    The rare decays b [yields] sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the b [yields] s[gamma] and b [yields] s + gluon dipole operators. The problem is investigated by considering the contributions of the [epsilon]-scalar field and the [epsilon]-dimensional operators that distinguish between the methods. The discrepancies come from the [epsilon]-dimensional four-quark operators in dimensional reduction. In the decay b [yields] sl[sup +]l[sup [minus

  8. Cytostatic effect of L-lysine-. cap alpha. -oxidase from Trichoderma harzianum Rifai and Trichoderma viride

    Energy Technology Data Exchange (ETDEWEB)

    Khaduev, S.Kh.; Zhukova, O.S.; Dobrynin, Ya.V.; Soda, K.; Berezov, T.T.

    1987-09-01

    Comparative data is given on the effect of the new antitumor enzyme LO, obtained from a Soviet strain of Trichoderma harzianum Rifai and from Trichoderma viride from Japan, on DNA and RNA synthesis in human ovarian carcinoma cells in culture and also the results of the action of LO from Tr. harzianum Rifai on protein synthesis. Specific precursors were added to the samples 1 hour before the end of incubation time: /sup 3/H-thymidine, the precursor for DNA synthesis, /sup 3/H-uridine for RNA synthesis, and /sup 3/H-leucine for protein synthesis.

  9. GPS/CAPS dual-mode software receiver

    Institute of Scientific and Technical Information of China (English)

    NING ChunLin; SHI HuLi; HU Chao

    2009-01-01

    The positioning of the GPS or Chinese Area Positioning System (CAPS) software receiver was developed on a software receiver platform.The structure of the GPSlCAPS dual-mode software receiver was put forward after analyzing the differences in the satellite identification,ranging code,spread spectrum,coordinate system,time system,carrier band,and navigation data between GPS and CAPS.Based on Matlab software on a personal computer,baseband signal processing and positioning procedures were completed using real GPS and CAPS radio frequency signals received by two antennas.Three kinds of experiments including GPS positioning,CAPS positioning,and GPS/CAPS positioning were carried out.Stability and precision of the results were analyzed and compared.The experimental results show that the precision of CAPS is similar to that of GPS,while the positioning precision of the GPS/CAPS dual-mode software receiver is 1-2 m higher than that of CAPS or GPS.The smallest average variance of the positioning can be obtained by using the GPS/CAPS dual-mode software receiver.

  10. GPS/CAPS dual-mode software receiver

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The positioning of the GPS or Chinese Area Positioning System (CAPS) software receiver was developed on a software receiver platform. The structure of the GPS/CAPS dual-mode software receiver was put forward after analyzing the differences in the satellite identification, ranging code, spread spectrum, coordinate system, time system, carrier band, and navigation data between GPS and CAPS. Based on Matlab software on a personal computer, baseband signal processing and positioning procedures were completed using real GPS and CAPS radio frequency signals received by two antennas. Three kinds of experiments including GPS positioning, CAPS positioning, and GPS/CAPS positioning were carried out. Stability and precision of the results were analyzed and compared. The experimental results show that the precision of CAPS is similar to that of GPS, while the positioning precision of the GPS/CAPS dual-mode software receiver is 1-2 m higher than that of CAPS or GPS. The smallest average variance of the positioning can be obtained by using the GPS/CAPS dual-mode software receiver.

  11. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  12. Teleportation via decay

    Indian Academy of Sciences (India)

    S Bose; P L Knight; M B Plenio; V Vedral

    2001-02-01

    We present a rare example of a decay mechanism playing a constructive role in quantum information processing. We show how the state of an atom trapped in a cavity can be teleported to a second atom trapped in a distant cavity by the joint detection of photon leakage from the cavities. The scheme, which is probabilistic, requires only a single three level atom in a cavity. We also show how this scheme can be modified to a teleportation with insurance.

  13. Decay of Polarized Delta

    OpenAIRE

    Ramachandran, G.; Venkataraya; Vidya, M. S.; Balasubramanyam, J.; Padmanabha, G.

    2009-01-01

    The resonance $\\Delta(1232)$ with spin-parity ${3 \\over 2}^+$, which contributes dominantly to the reactions like $\\gamma N \\to \\pi N$ and $NN \\to NN\\pi$ at intermediate energies, may be expected to be produced in characteristically different polarized spin states. As such an analysis of the decay of polarized delta is presented, which may be utilized to probe empirically the production mechanism. It is shown that measurements of the angular distributions of the pion and the polarization of t...

  14. Rare D Decays

    CERN Document Server

    Casey, Brendan

    2007-01-01

    We discuss several recent measurements of rare charmed hadron decays. Focus is placed on radiative and annihilation topologies highlighting their sensitivity to new physics and pointing out the strengths and weaknesses of different channels. We compare the different measurement techniques employed at fixed target and $e^+e^-$ dedicated charm experiments, B-factories, and the Tevatron experiments. Comparisons are also made to similar topologies in the beauty, strange, and top systems where appropriate.

  15. Charmless B decays

    Directory of Open Access Journals (Sweden)

    Martens Aurélien

    2014-04-01

    Full Text Available During 2011, LHCb has collected an integrated luminosity of 1.1 fb−1, giving rise to a large variety of measurements. Amongst these, measurements of CP violation in B decays play a central role. In particular CP violation measurements in charmless transitions of B mesons are of interest since they provide new or improved constraints on new physics contributions. These proceedings concentrate on LHCb results made publicin the first half of the year 2012.

  16. Alpha particles in fusion research

    International Nuclear Information System (INIS)

    This collection of 39 (mostly view graph) presentations addresses various aspects of alpha particle physics in thermonuclear fusion research, including energy balance and alpha particle losses, transport, the influence of alpha particles on plasma stability, helium ash, the transition to and sustainment of a burning fusion plasma, as well as alpha particle diagnostics. Refs, figs and tabs

  17. Quantifying Solar Wind-Polar Cap Interactions

    Science.gov (United States)

    Urban, K. D.; Gerrard, A. J.; Lanzerotti, L. J.; Weatherwax, A. T.; Huang, Y.

    2015-12-01

    It is well known that the solar wind is a major driver of ultra-low frequency [ULF] power at ground locations from low to high latitudes. However, due to the scarcity of deep polar cap magnetometer sites, it is not clear when, where, or if this is true deep inside the polar cap on open field lines where interplanetary magnetic field [IMF] ULF waves could possibly be directly detected. Given recent observations of very large Joule heating estimates from DMSP data, together with the large heating reported by the CHAMP satellite, it is important to understand the degree to which ULF waves in the solar wind can directly cause such heating. Using a time series of lagged correlation sequences ("dynamic correlograms") between GSM Bz ULF power (computed via data obtained from NASA's Advanced Composition Explorer [ACE] ahead of Earth in the solar wind) and the horizontal ULF power (H^2=N^2+E^2) from ground-based magnetometers in Earth's southern polar cap, we investigate the direct penetration of ULF waves from the solar wind into the polar ionosphere during a gamut of space weather conditions at a distributed network of Automated Geophysical Observatories [AGOs] in Antarctica. To infer causation, a predicted lag correlation maximum at each time step is computed by simply dividing the associated distance of ACE from Earth by the concurrent bulk solar wind speed. This technique helps parse out direct penetration of solar wind ULF waves from other sources (e.g., via leakage from closed field line resonances due to the bulk solar wind plasma viscously interacting at dawn/dusk flanks inducing Kelvin-Helmholtz instabilities [KHI] or compressional modes induced by impulses in solar wind dynamic pressure). The identified direct-penetrating ULF waves are related to the DMSP-derived Poynting fluxes by regression analysis, and conclusions are drawn for the importance of the ULF source for the measured heating.

  18. Search for B+ meson decay to a1+ K*0

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /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 /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /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. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /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. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist 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

    2011-08-11

    We present a search for the decay B{sup +} --> {alpha}{sup +}{sub 1}(1260)K*{sup 0}(892). The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent 465 million B{anti B} pairs produced in e{sup +}e{sup -} annihilation at the energy of the {Upsilon}(4S). We find no significant signal and set an upper limit at 90% confidence level on the product of branching fractions B(B{sup +} --> {alpha}{sup +}{sub 1}(1260)K*{sup 0}(892)) x B({alpha}{sup +}{sub 1}(1260) --> {pi}{sup +}{pi}{sup -}{pi}{sup +}) of 1.8 x 10{sup -6}.

  19. Radioactive decay data tables

    International Nuclear Information System (INIS)

    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

  20. Groundstates of nonlinear Choquard equations: existence, qualitative properties and decay asymptotics

    CERN Document Server

    Moroz, Vitaly

    2012-01-01

    We consider a semilinear elliptic problem [- \\Delta u + u = (I_\\alpha \\ast \\abs{u}^p) \\abs{u}^{p - 2} u \\quad\\text{in (\\mathbb{R}^N),}] where (I_\\alpha) is a Riesz potential and (p>1). This family of equations includes the Choquard or nonlinear Schr\\"odinger-Newton equation. For an optimal range of parameters we prove the existence of a positive groundstate solution of the equation. We also establish regularity and positivity of the groundstates and prove that all positive groundstates are radially symmetric and monotone decaying about some point. Finally, we derive the decay asymptotics at infinity of the groundstates.

  1. Decay scheme of the U{sup 2}35; Esquema de desintegracion del U-235

    Energy Technology Data Exchange (ETDEWEB)

    Gaeta, R.

    1965-07-01

    A study of the Th{sup 2}31 excited levels from the alpha decay of the U{sup 2}35, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U{sup 2}35, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs.

  2. Lambda_b -> Lambda l+ l- decay within family non-universal Z' model

    OpenAIRE

    Aliev, T. M.; Savci, M.

    2012-01-01

    We perform a comprehensive analysis of the rare "Lambda_b -> Lambda l+ l-" decay in the framework of family non-universal Z' model. It is shown that Z' gives considerable contribution to the decay width. Zero positions of the forward-backward asymmetry and alpha_theta parameter are shifted to the left compared to the Standard Model result. The obtained results could be tested in near future at LHC-b.

  3. HyperCP (E871) experiment at Fermilab: search for direct CP violation in hyperon decays

    Energy Technology Data Exchange (ETDEWEB)

    Leros, N.; Burnstein, R.A.; Chakravorty, A.; Chan, A.; Chen, Y.C.; Choong, W.S.; Clark, K.; Dukes, E.C.; Durandet, C.; Felix, J.; Gidal, G.; Gustafson, H.R.; Ho, C.; Holmstrom, T.; Huang, M.; James, C.; Jenkins, M.; Jones, T.; Kaplan, D.M.; Lederman, L.M.; Longo, M.J.; Lopez, F.; Lu, L.C.; Luebke, W.; Luk, K.B.; Moreno, G.; Nelson, K.S.; Park, H.K.; Perroud, J.P.; Rajaram, D.; Rubin, H.A.; Sosa, M.; Teng, P.K.; Turko, B.; Volk, J.; White, C.; White, S.L.; Zyla, P

    2001-05-01

    The Fermilab HyperCP experiment has accumulated the world's largest sample of {xi}{sup -} and {xi}-bar{sup +} hyperon decays within two running periods in 1997 and 1999. The primary goal of the experiment is to search for direct CP violation in the decay sequences {xi}{sup -} {yields} {lambda} {pi}{sup -} {yields} p {pi}{sup -} {pi}{sup -} and {xi}-bar{sup +} {yields} {lambda}-bar {pi}{sup +} {yields} p-bar {pi}{sup +} {pi}{sup +}. A violation of CP would manifest itself as a difference between the angular distribution of the proton and the antiproton in the {lambda} and {lambda}-bar helicity frame. The amount of data is enough to reach a statistical sensitivity of 1.4 x 10{sup -4} in the CP violating asymmetry A{sub {xi}}{sub {lambda}} = ({alpha}{sub {xi}} {alpha}{sub {lambda}} - {alpha}{sub {xi}}{sub -bar} {alpha}{sub {lambda}}{sub -bar})/({alpha}{sub {xi}} {alpha}{sub {lambda}} + {alpha}{sub {xi}}{sub -bar} {alpha}{sub {lambda}}{sub -bar}). We present an analysis method used to take into account the slight differences in the production of the {xi}{sup -} and {xi}-bar{sup +} samples. A preliminary results on A{sub {xi}}{sub {lambda}} at the level of a few 10{sup -3} and based on a few percent of the 1997 data will be presented.

  4. Selection of filter media in alpha air monitors for emergency environmental monitoring

    International Nuclear Information System (INIS)

    We have developed an alpha air monitor which is possible to measure rapidly and sensitively the concentrations of airborne alpha-emitting particles, such as plutonium, for the environmental monitoring at an accident of nuclear reprocessing plant. The monitor is designed to collect airborne alpha-emitting particles by drawing the ambient air through a filter and to detect the activity by alpha spectroscopy. In order to achieve high-sensitive measurements, selection of a suitable filter used in the monitor is considerably important. The most important requirement for the filter is that it has a high surface collection efficiency to obtain the sharpness of the alpha energy spectrum. This makes it easy to distinguish the alpha-ray peak of plutonium from the alpha spectrum of naturally occurring radon decay products in the environment. And the filter is also desired to have low resistance of the air flow so that particles can be collected at a high flowrate. We have made a comparison of the surface collection efficiency and pressure drop for the various filters. Types of the test filters, most of which are commercially available in Japan, were glass fiber, cellulose-glass fiber, membrane and so on. The surface collection efficiency has been evaluated by the following two indices. One was the sharpness of alpha-ray energy peaks of thoron decay products generated in a laboratory and collected in the fibers. The other was the background counts of radon decay products in a plutonium region by measuring alpha-ray energy spectrum of radon decay products collected in the filters by sampling of dust in the atmosphere. It was found that the PTFE (polytetrafluoroethylene) membrane filter with backing had a high surface collection efficiency and low pressure drop. The results of the test are described in detail in this paper. (author)

  5. Column: Factors Affecting Data Decay

    Directory of Open Access Journals (Sweden)

    Kevin Fairbanks

    2012-06-01

    Full Text Available In nuclear physics, the phrase decay rate is used to denote the rate that atoms and other particles spontaneously decompose. Uranium-235 famously decays into a variety of daughter isotopes including Thorium and Neptunium, which themselves decay to others. Decay rates are widely observed and wildly different depending on many factors, both internal and external. U-235 has a half-life of 703,800,000 years, for example, while free neutrons have a half-life of 611 seconds and neutrons in an atomic nucleus are stable.We posit that data in computer systems also experiences some kind of statistical decay process and thus also has a discernible decay rate. Like atomic decay, data decay fluctuates wildly. But unlike atomic decay, data decay rates are the result of so many different interplaying processes that we currently do not understand them well enough to come up with quantifiable numbers. Nevertheless, we believe that it is useful to discuss some of the factors that impact the data decay rate, for these factors frequently determine whether useful data about a subject can be recovered by forensic investigation.(see PDF for full column

  6. Recent results on tau decays

    International Nuclear Information System (INIS)

    New preliminary ARGUS results on τ decays are presented. We have measured the inclusive 3-prong branching ratio as well as the exclusive branching ratios for 6 major τ decay channels: τ- → ε-ν-bareντ.τ- → μ-ν-barμντ.τ- → π- /K-ντ.τ- → π-π-π-ντ.τ- → π-π0ντ and τ- → π- π- π+ π0 ντ†. Our results are in contradiction to the recent CELLO measurements, which indicate that the τ decay problem disappeared. A search was made for 26 different neutrinoless τ decays. No evidence has been found, that the τ decay problem might be connected to such neutrinoless decays. In addition, the hadronic final states of τ decays into π π0ντ and π-π-π+ντ have been analyzed. (author)

  7. B decays to open charm

    CERN Document Server

    Haines, Susan Carol

    2016-01-01

    Studies of $B$ meson decays to states involving open charm mesons in data recorded by the LHCb experiment have resulted in first observations of several new decay modes, including $B_s^{0} \\rightarrow D_s^{*\\mp} K^{\\pm}$, $B_s^{0} \\rightarrow \\overline{D}^{0} K_S^{0}$ and $B^{+} \\rightarrow D^{+} K^{+} \\pi^{-}$ decays. An upper limit has been placed on the branching fraction of $B_s^{0} \\rightarrow \\overline{D}^{0} f_0(980)$ decays. Measurements of other branching fractions, such as those of $B_s^{0} \\rightarrow D_s^{(*)+} D_s^{(*)-}$ decays, are the most precise to date. Additionally, amplitude analyses of $B^{0} \\rightarrow \\overline{D}^{0} \\pi^{+} \\pi^{-}$ and $B^{0} \\rightarrow \\overline{D}^{0} K^{+} \\pi^{-}$ decays have been performed, alongside the first $CP$ violation analysis using the Dalitz plot of $B^{0} \\rightarrow D K^{+} \\pi^{-}$ decays.

  8. Macrophage Capping Protein CapG Is a Putative Oncogene Involved in Migration and Invasiveness in Ovarian Carcinoma

    Directory of Open Access Journals (Sweden)

    J. Glaser

    2014-01-01

    Full Text Available The actin binding protein CapG modulates cell motility by interacting with the cytoskeleton. CapG is associated with tumor progression in different nongynecologic tumor entities and overexpression in breast cancer cell lines correlates with a more invasive phenotype in vitro. Here, we report a significant CapG overexpression in 18/47 (38% of ovarian carcinomas (OC analyzed by qRealTime-PCR analyses. Functional analyses in OC cell lines through siRNA mediated CapG knockdown and CapG overexpression showed CapG-dependent cell migration and invasiveness. A single nucleotide polymorphism rs6886 inside the CapG gene was identified, affecting a CapG phosphorylation site and thus potentially modifying CapG function. The minor allele frequency (MAF of SNP rs6886 (c.1004A/G was higher and the homozygous (A/A, His335 genotype was significantly more prevalent in patients with fallopian tube carcinomas (50% as in controls (10%. With OC being one of the most lethal cancer diseases, the detection of novel biomarkers such as CapG could reveal new diagnostic and therapeutic targets. Moreover, in-depth analyses of SNP rs6886 related to FTC and OC will contribute to a better understanding of carcinogenesis and progression of OC.

  9. ON THE RELATIONSHIP BETWEEN THE CORONAL MAGNETIC DECAY INDEX AND CORONAL MASS EJECTION SPEED

    Energy Technology Data Exchange (ETDEWEB)

    Xu Yan; Liu Chang; Jing Ju; Wang Haimin, E-mail: yx2@njit.edu [Space Weather Research Lab, Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102-1982 (United States)

    2012-12-10

    Numerical simulations suggest that kink and torus instabilities are two potential contributors to the initiation and prorogation of eruptive events. A magnetic parameter called the decay index (i.e., the coronal magnetic gradient of the overlying fields above the eruptive flux ropes) could play an important role in controlling the kinematics of eruptions. Previous studies have identified a threshold range of the decay index that distinguishes between eruptive and confined configurations. Here we advance the study by investigating if there is a clear correlation between the decay index and coronal mass ejection (CME) speed. Thirty-eight CMEs associated with filament eruptions and/or two-ribbon flares are selected using the H{alpha} data from the Global H{alpha} Network. The filaments and flare ribbons observed in H{alpha} associated with the CMEs help to locate the magnetic polarity inversion line, along which the decay index is calculated based on the potential field extrapolation using Michelson Doppler Imager magnetograms as boundary conditions. The speeds of CMEs are obtained from the LASCO C2 CME catalog available online. We find that the mean decay index increases with CME speed for those CMEs with a speed below 1000 km s{sup -1} and stays flat around 2.2 for the CMEs with higher speeds. In addition, we present a case study of a partial filament eruption, in which the decay indices show different values above the erupted/non-erupted part.

  10. Selection of satellite constellation framework of CAPS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the idea of transmitting the satellite navigation and positioning system, taking the distribution and variation of the Position Dilution of Precision factor (PDOP), which is closely related with the precision of navigation and positioning, within the China area as the primary criterion, we analyze and discuss the tentative plan of constellation configuration consisting of geosynchronous orbit (GEO) communication satellites and inclined geosynchronous orbit (IGSO) satellites for the transmitting Chinese Area Positioning System (CAPS). We emphatically consider the effect on the PDOP by the three major orbit parameters including the inclination, eccentricity and right ascension of the ascend- ing node (RAAN) of IGSO satellites, to research the strategies of the constellation configuration of CAPS through software emulation. Various constellation configurations are analyzed and compared and the results show that the constellation configuration, consisting of three IGSO communication satellites in three orbits with the same inclination as 50°, the difference in RAAN as 120° and the same "8" shaped ground track centered near 115°E and four or five GEO communication satellites within 60°E to 150°E, can satisfy the requirement that Chinese domain is availably covered and the navigation and positioning with high precision could be obtained. Three relatively excellent constellation configurations are initially suggested and some concerned issues are discussed in this work.

  11. Magnetically capped rolled-up nanomembranes.

    Science.gov (United States)

    Streubel, Robert; Thurmer, Dominic J; Makarov, Denys; Kronast, Florian; Kosub, Tobias; Kravchuk, Volodymyr; Sheka, Denis D; Gaididei, Yuri; Schäfer, Rudolf; Schmidt, Oliver G

    2012-08-01

    Modifying the curvature in magnetic nanostructures is a novel and elegant way toward tailoring physical phenomena at the nanoscale, allowing one to overcome limitations apparent in planar counterparts. Here, we address curvature-driven changes of static magnetic properties in cylindrically curved magnetic segments with different radii of curvature. The curved architectures are prepared by capping nonmagnetic micrometer- and nanometer-sized rolled-up membranes with a soft-magnetic 20 nm thick permalloy (Ni(80)Fe(20)) film. A quantitative comparison between the magnetization reversal processes in caps with different diameters is given. The phase diagrams of magnetic equilibrium domain patterns (diameter versus length) are generated. For this, joint experimental, including X-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM), and theoretical studies are carried out. The anisotropic magnetostatic interaction in cylindrically curved architectures originating from the thickness gradient reduces substantially the magnetostatic interaction between closely packed curved nanowires. This feature is beneficial for racetrack memory devices, since a much higher areal density might be achieved than possible with planar counterparts.

  12. Comparison of Polar Cap (PC) index calculations.

    Science.gov (United States)

    Stauning, P.

    2012-04-01

    The Polar Cap (PC) index introduced by Troshichev and Andrezen (1985) is derived from polar magnetic variations and is mainly a measure of the intensity of the transpolar ionospheric currents. These currents relate to the polar cap antisunward ionospheric plasma convection driven by the dawn-dusk electric field, which in turn is generated by the interaction of the solar wind with the Earth's magnetosphere. Coefficients to calculate PCN and PCS index values from polar magnetic variations recorded at Thule and Vostok, respectively, have been derived by several different procedures in the past. The first published set of coefficients for Thule was derived by Vennerstrøm, 1991 and is still in use for calculations of PCN index values by DTU Space. Errors in the program used to calculate index values were corrected in 1999 and again in 2001. In 2005 DMI adopted a unified procedure proposed by Troshichev for calculations of the PCN index. Thus there exists 4 different series of PCN index values. Similarly, at AARI three different sets of coefficients have been used to calculate PCS indices in the past. The presentation discusses the principal differences between the various PC index procedures and provides comparisons between index values derived from the same magnetic data sets using the different procedures. Examples from published papers are examined to illustrate the differences.

  13. PANDA EMC backward end-cap mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Capozza, Luigi; Ceballos, Jorge; Lin, Dexu; Maas, Frank; Rodriguez, David; Valente, Roserio; Welzel, Felix [Helmholtz-Institut Mainz (Germany); Collaboration: PANDA-Collaboration

    2013-07-01

    The PANDA experiment at the FAIR facility will be a multipurpose hermetic spectrometer covering the full solid angle range. A key role for several physics cases will be played by the electromagnetic calorimeter. This includes ca. 15000 PbWO{sub 4} scintillating crystals arranged in a central barrel, a forward and a backward end-cap. The backward end-cap of the PANDA electromagnetic calorimeter is composed by 540 straight crystals covering the scattering angles between 147 {sup circle} and 161 {sup circle}. They are housed in the so-called alveoli which are carbon fibre boxes, providing both strength and low material budget. The crystals are to work at -25 C in order to improve the light yield. To achieve this temperature a cooling system and thermal insulation are needed. The cooling system removes the heat coming from the electronics and through walls, cables and mechanical supports. Vacuum insulated panels are installed as a thermal shielding. Avalanche Photodiodes (APD) have been chosen as photon detectors, since they are still functional under strong magnetic fields. ASIC chips will be used to amplify the APD signal, this preamplifier features low noise and low heat generation. Due to the weight of this detector, it will be supported from the outside of the PANDA target spectrometer in a counter lever arm position.

  14. Arrays of magnetic nanoparticles capped with alkylamines

    Indian Academy of Sciences (India)

    P John Thomas; P Saravanan; G U Kulkarni; C N R Rao

    2002-02-01

    Magnetic metal and metal oxide nanoparticles capped with alkylamines have been synthesized and characterized by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray analysis and magnetization measurements. Core-shell Pd–Ni particles with composition, Pd561Ni3000, (diameter ∼ 3.3 nm) are superparamagnetic at 5 K and organize themselves into two-dimensional crystalline arrays. Similar arrays are obtained with Pd561Ni3000Pd1500 nanoparticles containing an additional Pd shell. Magnetic spinel particles of -Fe2O3, Fe3O4 and CoFe2O4 of average diameters in the 4–6 nm range coated with octylamine are all supermagnetic at room temperature and yield close-packed disordered arrays. Relatively regular arrays are formed by dodecylamine-capped Fe3O4 nanoparticles (∼ 8.6 nm diameter) while well-ordered hexagonal arrays were obtained with octylamine-covered Co3O4 nanoparticles (∼ 4.2 nm diameter).

  15. Acoustic Monitoring of the Arctic Ice Cap

    Science.gov (United States)

    Porter, D. L.; Goemmer, S. A.; Chayes, D. N.

    2012-12-01

    Introduction The monitoring of the Arctic Ice Cap is important economically, tactically, and strategically. In the scenario of ice cap retreat, new paths of commerce open, e.g. waterways from Northern Europe to the Far East. Where ship-going commerce is conducted, the U.S. Navy and U.S. Coast Guard have always stood guard and been prepared to assist from acts of nature and of man. It is imperative that in addition to measuring the ice from satellites, e.g. Icesat, that we have an ability to measure the ice extent, its thickness, and roughness. These parameters play an important part in the modeling of the ice and the processes that control its growth or shrinking and its thickness. The proposed system consists of three subsystems. The first subsystem is an acoustic source, the second is an array of geophones and the third is a system to supply energy and transmit the results back to the analysis laboratory. The subsystems are described below. We conclude with a plan on how to tackle this project and the payoff to the ice cap modeler and hence the users, i.e. commerce and defense. System Two historically tested methods to generate a large amplitude multi-frequency sound source include explosives and air guns. A new method developed and tested by the University of Texas, ARL is a combustive Sound Source [Wilson, et al., 1995]. The combustive sound source is a submerged combustion chamber that is filled with the byproducts of the electrolysis of sea water, i.e. Hydrogen and Oxygen, an explosive mixture which is ignited via a spark. Thus, no additional compressors, gases, or explosives need to be transported to the Arctic to generate an acoustic pulse capable of the sediment and the ice. The second subsystem would be geophones capable of listening in the O(10 Hz) range and transmitting that data back to the laboratory. Thus two single arrays of geophones arranged orthogonal to each other with a range of 1000's of kilometers and a combustive sound source where the two

  16. Alpha/sub 1/ receptor coupling events initiated by methoxy-substituted tolazoline partial agonists

    Energy Technology Data Exchange (ETDEWEB)

    Wick, P.; Keung, A.; Deth, R.

    1986-03-01

    A series of mono- and dimethyoxy substituted tolazoline derivatives, known to be partial agonists at the alpha/sub 1/ receptor, were compared with the ..cap alpha../sub 1/ selective full agonist phenylephrine (PE) on isolated strips of rabbit aorta Agonist activity was evaluated in contraction, /sup 45/Ca influx, /sup 45/Ca efflux, and /sup 32/P-Phospholipid labelling studies. Maximum contractile responses for the 2-, 3-, and 3, 5- methoxy substituted tolazoline derivatives (10/sup -5/M) were 53.8, 67.6 and 99.7% of the PE (10/sup -5/M) response respectively. These same partial agonists caused a stimulation of /sup 45/Ca influx to the extent of 64, 86, and 95% of the PE response respectively. In /sup 45/Ca efflux studies, (a measure of the intracellular Ca/sup +2/ release) the tolazolines caused: 30%, 63%, and 78% of the PE stimulated level. /sup 32/P-Phosphatidic acid (PA) labelling was measured as an index of PI turnover after ..cap alpha../sub 1/ receptor stimulation. Compared to PE, the 2-, 3-, and 3,5- methoxy substituted tolazoline derivatives caused 22, 46, and 72% PA labelling. The above values are all in reasonable accord with the rank order or agonist activity shown in maximum contractile responses. The results of this investigation suggest that partial agonists stimulate ..cap alpha.. receptor coupling events at a level which is quantitatively comparable to their potencies in causing contraction of arterial smooth muscle.

  17. ALPHA MIS: Reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Lovin, J.K.; Haese, R.L.; Heatherly, R.D.; Hughes, S.E.; Ishee, J.S.; Pratt, S.M.; Smith, D.W.

    1992-02-01

    ALPHA is a powerful and versatile management information system (MIS) initiated and sponsored and by the Finance and Business Management Division of Oak Ridge National Laboratory, who maintain and develop it in concert with the Business Systems Division for its Information Center. A general-purpose MIS, ALPHA allows users to access System 1022 and System 1032 databases to obtain and manage information. From a personal computer or a data terminal, Energy Systems employees can use ALPHA to control their own report reprocessing. Using four general commands (Database, Select, Sort, and Report) they can (1) choose a mainframe database, (2) define subsets within it, (3) sequentially order a subset by one or more variables, and (4) generate a report with their own or a canned format.

  18. Identification of the DNA sequences encoding the large subunit of the mRNA-capping enzyme of vaccinia virus

    International Nuclear Information System (INIS)

    The DNA sequences encoding the large subunit of the mRNA-capping enzyme of vaccinia virus were located on the viral genome. The formation of an enzyme-guanylate covalent intermediate labeled with [alpha-32P]GTP allowed the identification of the large subunit of the capping enzyme and was used to monitor the appearance of the enzyme during the infectious cycle. This assay confirmed that after vaccinia infection, a novel 84,000-molecular-weight polypeptide corresponding to the large subunit was rapidly synthesized before viral DNA replication. Hybrid-selected cell-free translation of early viral mRNA established that vaccinia virus encoded a polypeptide identical in molecular weight with the 32P-labeled 84,000-molecular-weight polypeptide found in vaccinia virions. Like the authentic capping enzyme, this virus-encoded cell-free translation product bound specifically to DNA-cellulose. A comparison of the partial proteolytic digestion fragments generated by V8 protease, chymotrypsin, and trypsin demonstrated that the 32P-labeled large subunit and the [35S]methionine-labeled cell-free translation product were identical. The mRNA encoding the large subunit of the capping enzyme was located 3.1 kilobase pairs to the left of the HindIII D restriction fragment of the vaccinia genome. Furthermore, the mRNA was determined to be 3.0 kilobases in size, and its 5 and 3 termini were precisely located by S1 nuclease analysis

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

    CERN Document Server

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

    2015-01-01

    [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...

  20. Analysis list: Cap-H2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Cap-H2 Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Cap-H2....1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Cap-H2.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Ca...p-H2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cap-H2.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

  1. Design and Performance of Capping Layers for EUV Multilayer Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Bajt, S; Chapman, H N; Nuygen, N; Alameda, J; Robinson, J C; Malinowski, M; Gullikson, E; Aquila, A; Tarrio, C; Grantham, S

    2003-03-10

    The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.

  2. Analyses of Current And Wave Forces on Velocity Caps

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Buhrkall, Jeppe; Eskesen, Mark C. D.;

    2015-01-01

    Velocity caps are often used in connection with for instance offshore intake sea water for the use of for cooling water for power plants or as a source for desalinization plants. The intakes can also be used for river intakes. The velocity cap is placed on top of a vertical pipe. The vertical pipe......) this paper investigates the current and wave forces on the velocity cap and the vertical cylinder. The Morison’s force model was used in the analyses of the extracted force time series in from the CFD model. Further the distribution of the inlet velocities around the velocity cap was also analyzed in detail...

  3. Effect of swim cap model on passive drag.

    Science.gov (United States)

    Gatta, Giorgio; Zamparo, Paola; Cortesi, Matteo

    2013-10-01

    Hydrodynamics plays an important role in swimming because even small decreases in a swimmer's drag can lead to performance improvements. During the gliding phases of a race, the head of a swimmer is an important point of impact with the fluid, and the swim cap, even if it covers only a small portion of the swimmer's body, can have an influence on drag. The purpose of this study was to investigate the effects on passive drag (Dp) of wearing 3 different types of swim caps (LSC: a lycra cap; CSC: a silicone cap; HSC: a silicone helmet cap without seams). Sixteen swimmers were tested at 3 velocities (1.5, 1.7, 1.9 m·s), and the Dp measurements were repeated at each condition 5 times. A statistical analysis revealed significant differences in drag (p swim cap is the most rigid, the most adherent to the swimmer's head, and does not allow the formation of wrinkles compared with the other 2 investigated swim caps. Therefore, the following conclusions can be made: (a) swimmers should take care when selecting their swim cap if they want to improve the fluid dynamics at the "leading edge" of their body and (b) because Dp is affected by the swim cap model, care should be taken when comparing data from different studies, especially at faster investigated speeds.

  4. Measurements of the CKM Angle Alpha at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Is Radioactive Decay Really Exponential?

    CERN Document Server

    Aston, Philip J

    2012-01-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating meth...

  6. Hadronic Decays of Charm

    OpenAIRE

    Stenson, Kevin

    2001-01-01

    Recent hadronic charm decay results from fixed-target experiments are presented. New measurements of the D0 to K-K+K-pi+ branching ratio are shown as are recent results from Dalitz plot fits to D+ to K-K+pi+, pi+pi-pi+, K-pi+pi+, K+pi-pi+ and D_s+ to pi+pi-pi+, K+pi-pi+. These fits include measurements of the masses and widths of several light resonances as well as strong evidence for the existence of two light scalar particles, the pipi resonance sigma and the Kpi resonance kappa.

  7. Tau Decays into Kaons

    OpenAIRE

    Finkemeier, Markus; Mirkes, Erwin

    1995-01-01

    Predictions for semi-leptonic decay rates of the tau lepton into two and three meson final states with one or two kaons are derived, including a discussion of K_S pi- K_S, K_L pi- K_L and K_S pi- K_L. The hadronic matrix elements are expressed in terms of form factors, which can be predicted by chiral Lagrangians supplemented by informations about all possible low-lying resonances in the different channels. Isospin symmetry relations among the different final states are carefully taken into a...

  8. On the absence of appreciable half-life changes in alpha emitters cooled in metals to 1 Kelvin and below

    CERN Document Server

    Stone, N J; Richards, P; Stone, J R; Veskovic, M; Williams, D A

    2006-01-01

    The recent suggestion that dramatic changes may occur in the lifetime of alpha and beta decay when the activity, in a pure metal host, is cooled to a few Kelvin, is examined in the light of published low temperature nuclear orientation (LTNO) experiments, with emphasis here on alpha decay. In LTNO observations are made of the anisotropy of radioactive emissions with respect to an axis of orientation. Correction of data for decay of metallic samples held at temperatures at and below 1 Kelvin for periods of days and longer has been a routine element of LTNO experiments for many years. No evidence for any change of half life on cooling, with an upper level of less than 1%, has been found, in striking contrast to the predicted changes, for alpha decay, of several orders of magnitude. The proposal that such dramatic changes might alleviate problems of disposal of long-lived radioactive waste is shown to be unrealistic.

  9. Fluorescent heavy metal cation sensing with water dispersible 2MPA capped CdSe/ZnS quantum dots

    International Nuclear Information System (INIS)

    Here we report the fluorescence response of water dispersible CdSe/ZnS core–shell quantum dots capped with 2-mercaptopropionic acid (2MPA) towards different concentrations of heavy metal cations, namely mercury, lead and cadmium. Upon exposure to different concentrations of the various metal cations, a concentration-dependent decrease in the QDs’ fluorescence emission was observed, which was decaying exponential in nature. The greatest degree of quenching was achieved in the presence of mercury. The resultant quantum dots were subsequently characterised by UV–vis spectroscopy, photo-luminescent spectroscopy, Raman Spectroscopy and X-ray diffraction. The quantitative detection of mercury, lead and cadmium cations by these capped quantum dots makes them exciting candidates for heavy metal sensing applications

  10. Fluorescent heavy metal cation sensing with water dispersible 2MPA capped CdSe/ZnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, D., E-mail: vasudevand@rediffmail.com [Central Electrochemical Research Institute, Karaikudi 630006, Tamilnadu (India); Trinchi, Adrian; Hardin, Simon G.; Cole, Ivan S. [CSIRO Materials Science and Engineering, Private Bag 33, Clayton South MDC 3169 (Australia)

    2015-10-15

    Here we report the fluorescence response of water dispersible CdSe/ZnS core–shell quantum dots capped with 2-mercaptopropionic acid (2MPA) towards different concentrations of heavy metal cations, namely mercury, lead and cadmium. Upon exposure to different concentrations of the various metal cations, a concentration-dependent decrease in the QDs’ fluorescence emission was observed, which was decaying exponential in nature. The greatest degree of quenching was achieved in the presence of mercury. The resultant quantum dots were subsequently characterised by UV–vis spectroscopy, photo-luminescent spectroscopy, Raman Spectroscopy and X-ray diffraction. The quantitative detection of mercury, lead and cadmium cations by these capped quantum dots makes them exciting candidates for heavy metal sensing applications.

  11. Molecular decay of enamel matrix protein genes in turtles and other edentulous amniotes

    OpenAIRE

    Meredith Robert W; Gatesy John; Springer Mark S

    2013-01-01

    Abstract Background Secondary edentulism (toothlessness) has evolved on multiple occasions in amniotes including several mammalian lineages (pangolins, anteaters, baleen whales), birds, and turtles. All edentulous amniote clades have evolved from ancestors with enamel-capped teeth. Previous studies have documented the molecular decay of tooth-specific genes in edentulous mammals, all of which lost their teeth in the Cenozoic, and birds, which lost their teeth in the Cretaceous. By contrast wi...

  12. Comprehensive decay law for emission of charged particles and exotic cluster radioactivity

    Indian Academy of Sciences (India)

    Basudeb Sahu

    2014-04-01

    A general decay formula for the emission of charged particles from metastable nuclei is developed based on the basic phenomenon of resonances occurring in quantum scattering process under Coulomb-nuclear potential. It relates the half-lives of radioactive decays with the values of the outgoing elements with masses and charges of the nuclei involved in the decay. The relation is found to be a generalization of the Geiger–Nuttall law in radioactivity and explains well all the known emissions of charged particles including clusters, alpha and proton.

  13. BIPAL - a data library for computing the burnup of fissionable isotopes and products of their decay

    International Nuclear Information System (INIS)

    The BIPAL databank contains data on 100 heavy metal isotopes starting with 206Tl and finishing with 253Es. Four are stable, the others are unstable. The following data are currently stored in the databank: the serial number and name of isotopes, decay modes and, for stable isotopes, the isotopic abundance (%), numbers of P decays and Q captures, numbers of corresponding final products, branching ratios, half-lives and their units, decay constants, thermal neutron captures, and fission cross sections, and other data (mainly alpha, beta and gamma intensities). The description of data and a printout of the BIPAL library are presented. (J.B.)

  14. Measurement of the $\\eta\\to 3\\pi^{0}$ slope parameter $\\alpha$ with the KLOE detector

    CERN Document Server

    Ambrosino, F; Antonelli, M; Archilli, F; Beltrame, P; Bencivenni, G; Bini, C; Bloise, C; Bocchetta, S; Bossi, F; Branchini, P; Campana, P; Capon, G; Capussela, T; Ceradini, F; Ciambrone, P; De Lucia, E; De Santis, A; De Simone, P; De Zorzi, G; Denig, A; Di Domenico, A; Di Donato, C; Di Micco, B; Dreucci, M; Felici, G; Ferrari, A; Fiore, S; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Jacewicz, M; Kluge, W; Kulikov, V; Lee-Franzini, J; Martini, M; Massarotti, P; Meola, S; Miscetti, S; Moulson, M; Müller, S; Murtas, F; Napolitano, M; Nguyen, F; Palutan, M; Passeri, A; Patera, V; Perfetto, F; Santangelo, P; Sciascia, B; Sciubba, A; Spadaro, T; Taccini, C; Tortora, L; Valente, P; Venanzoni, G; Versaci, R; Xu, G

    2010-01-01

    We present a measurement of the slope parameter $\\alpha$ for the $\\eta\\to 3\\pi^{0}$ decay, with the KLOE experiment at the DA$\\Phi$NE $\\phi$-factory, based on a background free sample of $\\sim$ 17 millions $\\eta$ mesons produced in $\\phi$ radiative decays. By fitting the event density in the Dalitz plot we determine $\\alpha = -0.0301 \\pm 0.0035\\,stat\\;_{-0.0035}^{+0.0022}\\,syst\\,$. The result is in agreement with recent measurements from hadro- and photo-production experiments.

  15. Evaluation of (alpha,n) Induced Neutrons as a Background for Dark Matter Experiments

    CERN Document Server

    Mei, D -M; Hime, A

    2008-01-01

    Neutrons from ($\\alpha$,n) reaction through thorium and uranium decays are important sources of background for direct dark matter detection. Neutron yield and energy spectrum from a range of materials that are used to build dark matter detectors are calculated and tabulated. In addition to thorium and uranium decays, we found that $\\alpha$ particles from samarium that is often doped in the window material of photomultiplier (PMT) are also an important source of neutron yield. The results in this paper can be used as the input in the Monte Carlo simulation for many materials that will be used for next generation experiments.

  16. Evidence against solar influence on nuclear decay constants

    Directory of Open Access Journals (Sweden)

    S. Pommé

    2016-10-01

    Full Text Available The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10−6 to 10−5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  17. Evidence against solar influence on nuclear decay constants

    Science.gov (United States)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Unterweger, M.; Fitzgerald, R.; Bergeron, D. E.; Pibida, L.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2016-10-01

    The hypothesis that proximity to the Sun causes variation of decay constants at permille level has been tested and disproved. Repeated activity measurements of mono-radionuclide sources were performed over periods from 200 days up to four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and are attributable to instabilities in the instrumentation and measurement conditions. The most stable activity measurements of alpha, beta-minus, electron capture, and beta-plus decaying sources set an upper limit of 0.0006% to 0.008% to the amplitude of annual oscillations in the decay rate. Oscillations in phase with Earth's orbital distance to the Sun could not be observed within a 10-6 to 10-5 range of precision. There are also no apparent modulations over periods of weeks or months. Consequently, there is no indication of a natural impediment against sub-permille accuracy in half-life determinations, renormalisation of activity to a distant reference date, application of nuclear dating for archaeology, geo- and cosmochronology, nor in establishing the SI unit becquerel and seeking international equivalence of activity standards.

  18. 211Po - Comments on Evaluation of Decay Data

    International Nuclear Information System (INIS)

    This evaluation was completed in August 2009. The literature available by December 31st, 2008 was included. Evaluation Procedures: The Limitation of Relative Statistical Weight (LWM) method was applied for averaging numbers throughout this evaluation; this method was implemented by using the computer code LWEIGHT, ver. 4 (designed for Excel, MS Office). The uncertainty assigned to an average value in this evaluation is never lower than the lowest uncertainty of any of the experimental input values. Decay Scheme; 211Po decays 100% by alpha particle emissions, mainly to the ground state of 207Pb. The most recent evaluations of the 211Po nuclear structure and decay data, published in Nuclear Data Sheets, were done by E. Browne (2004) and M.J. Martin (1993). In the present evaluation, the spin, parity and energy of the levels, together with the multipolarities and mixing ratios of the γ-ray transitions, have been adopted from the A=207 ENSDF mass-chain evaluation 1993Ma73.This data evaluation refers only to the decay of the 211Po ground state, and not to the decay of the 211Po metastable state at 1462 keV (with a half-life of 25.2 s)

  19. Wood decay at sea

    Science.gov (United States)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  20. Co-Decaying Dark Matter

    CERN Document Server

    Dror, Jeff Asaf; Ng, Wee Hao

    2016-01-01

    We propose a new mechanism for thermal dark matter freezeout, termed Co-Decaying Dark Matter. Multi-component dark sectors with degenerate particles and out-of-equilibrium decays can co-decay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles, rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross-section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes co-decaying dark matter.

  1. Dark decay of Top quark

    CERN Document Server

    Kong, Kyoungchul; Park, Myeonghun

    2014-01-01

    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 new 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 sigma 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.

  2. Carpentier, la otra novela (cap. IV

    Directory of Open Access Journals (Sweden)

    Urbano Martínez Carmenate

    2014-07-01

    Full Text Available El presente ensayo está extraído de la obra inédita de Urbano Martínez Carmenate, Carpentier, la otra novela (cap. IV. Ofrece una mirada sobre los primeros años de la trayectoria profesional de Alejo Carpentier. Se muestra cómo, durante la década de 1920, se inicia como periodista y cronista teatral. A la vez, comienzan sus conexiones con el Grupo Minorista, que desempeña un papel destacado en la etapa republicana en Cuba. También se contempla su viaje a México en 1926, que constituye su primer contacto directo con la naturaleza y la cultura americanas.

  3. Carpentier, la otra novela (cap. IV

    Directory of Open Access Journals (Sweden)

    Urbano Martínez Carmenate

    2014-06-01

    Full Text Available El presente ensayo está extraído de la obra inédita de Urbano Martínez Carmenate, Carpentier, la otra novela (cap. IV. Ofrece una mirada sobre los primeros años de la trayectoria profesional de Alejo Carpentier. Se muestra cómo, durante la década de 1920, se inicia como periodista y cronista teatral. A la vez, comienzan sus conexiones con el Grupo Minorista, que desempeña un papel destacado en la etapa republicana en Cuba. También se contempla su viaje a México en 1926, que constituye su primer contacto directo con la naturaleza y la cultura americanas.

  4. Three-dimensional drift chambers of the DCBA experiment for neutrinoless double beta decay search

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T., E-mail: ishikawat@hakone.phys.metro-u.ac.j [Tokyo Metropolitan University, Hachioji, Tokyo 192-0398 (Japan); Igarashi, H.; Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji, Tokyo 192-0398 (Japan); Ishihara, N.; Iwai, G.; Iwase, H.; Kato, Y.; Kawai, M.; Kondou, Y.; Haruyama, T.; Inagaki, T.; Makida, Y.; Ohama, T.; Takahashi, K.; Yamada, Y. [High Energy Accel, Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Tashiro, E.; Ishizuka, T. [Shizuoka University, Naka, Hamamatsu, Shizuoka 432-8011 (Japan); Kitamura, S. [Nihon Institute of Medical Science, Iruma-gun, Saitama 350-0435 (Japan); Teramoto, Y. [Osaka City University, Sumiyoshi, Osaka 558-8585 (Japan); Nakano, I. [Okayama University, Okayama 700-8530 (Japan)

    2011-02-01

    The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutrinoless double beta decay (0{nu}{beta}{beta}). The half-life of 0{nu}{beta}{beta} is expected to give us the information of Majorana nature and the absolute mass scale of neutrinos. A prototype test apparatus DCBA-T2 has the energy resolution of about 150 keV (FWHM) around 1 MeV. In order to check the detector performance, engineering runs detecting double beta decay of {sup 100}Mo started in May 2009 using natural Mo, which contains 9.6% of {sup 100}Mo. Ten candidates of the double beta decay ({beta}{beta}) have been detected so far. It has been found that the background events due to {sup 214}Bi decay are distinguishable from the double beta decays by detecting {alpha}-particles from {sup 214}Po.

  5. A novel approach to the systematization of α-decaying nuclei, based on shell structures

    Science.gov (United States)

    Yarman, Tolga; Zaim, Nimet; Amon Susam, Lidya; Kholmetskii, Alexander; Arık, Metin; Azmi Altıntaş, Ali; Ozaydin, Fatih

    2016-05-01

    We provide a novel systematization of α-decaying nuclei, starting with the classically adopted mechanism. The decay half-life of an α-disintegrating nucleus is framed, supposing that i) the α-particle is born inside the parent, then ii) it keeps on hitting the barrier, while it runs back and forth inside the parent, and hitting each time the barrier, and iii) it finally tunnels through the barrier. One can, knowing the decay half-life, consider the probability that the α-particle is born within the parent, before it is emitted, as a parameter. Under all circumstances, the decay appears to be governed by the shell structure of the given nucleus. Our approach well allows to incorporate (not only even-even nuclei, but) all nuclei, decaying via throwing an alpha particle. Though herein, we limit ourselves with just even-even nuclei, in the aim of comparing our results with the existing Geiger-Nuttal results.

  6. Radiative Decay of Neutron-Unbound Intruder States in $^{19}$O

    CERN Document Server

    Dungan, R; Tripathi, Vandana; Volya, A; Kravvaris, K; Abromeit, B; Caussyn, D D; Morrow, S; Parker, J J; Tai, P -L; VonMoss, J M

    2015-01-01

    The $^{9}$Be($^{14}$C, $\\alpha$$\\gamma$) reaction at E$_{Lab}$=30 and 35 MeV was used to study excited states of $^{19}$O. The Florida State University (FSU) $\\gamma$ detector array was used to detect $\\gamma$ radiation in coincidence with charged particles detected and identified with a silicon $\\Delta$E-E particle telescope. Gamma decays have been observed for the first time from six states ranging from 368 to 2147 keV above the neutron separation energy (S$_{n}$=3962 keV) in $^{19}$O. The $\\gamma$ decaying states are interspersed among states previously observed to decay by neutron emission. The ability of electromagnetic decay to compete successfully with neutron decay is explained in terms of neutron angular momentum barriers and small spectroscopic factors implying higher spin and complex structure for these intruder states. These results illustrate the need for complementary experimental approaches to best illuminate the complete nuclear structure.

  7. The $\\alpha_S$ Dependence of Parton Distributions

    OpenAIRE

    Martin, A. D.; Stirling, W. J.; Roberts, R G

    1995-01-01

    We perform next-to-leading order global analyses of deep inelastic and related data for different fixed values of $\\alpha_S (M_Z^2)$. We present sets of parton distributions for six values of $\\alpha_S$ in the range 0.105 to 0.130. We display the $(x, Q^2)$ domains with the largest parton uncertainty and we discuss how forthcoming data may be able to improve the determination of the parton densities.

  8. Yrast decays in 43K

    International Nuclear Information System (INIS)

    High-spin states in 43K were studied using the 9Be(36S,pnγ)43K reaction. Threefold (pγ1γ2) coincidence data and γ-ray intensity ratios were used to establish a decay scheme and identify negative- and positive-parity yrast decay chains. The 15/2- yrast state is relatively poorly aligned prior to decay. Energies of positive-parity levels predicted by Johnstone are in good agreement with experiment

  9. Invariants of free turbulent decay

    OpenAIRE

    Llor, Antoine

    2006-01-01

    In practically all turbulent flows, turbulent energy decay is present and competes with numerous other phenomena. In Kolmogorov's theory, decay proceeds by transfer from large energy-containing scales towards small viscous scales through the "inertial cascade." Yet, this description cannot predict an actual decay rate, even in the simplest case of homogeneous isotropic turbulence (HIT). As empirically observed over 50 years, the steepness of the "infrared" spectrum - at scales larger than ene...

  10. Particle decay in inflationary cosmology

    OpenAIRE

    Boyanovsky, D.; de Vega, H. J.

    2004-01-01

    We investigate the relaxation and decay of a particle during inflation by implementing the dynamical renormalization group. This investigation allows us to give a meaningful definition for the decay rate in an expanding universe. As a prelude to a more general scenario, the method is applied here to study the decay of a particle in de Sitter inflation via a trilinear coupling to massless conformally coupled particles, both for wavelengths much larger and much smaller than the Hubble radius. F...

  11. Rare charm decays at LHCb

    CERN Document Server

    Kochebina, Olga

    2014-01-01

    Flavour-changing neutral current decays such as c ! ul + l are highly suppressed in the Standard Model, but may be enhanced by New Physics. The latest searches for such decays at LHCb based on 1.0 fb 1 of data collected in 2011 are presented in this document. Two decays, 2-body D 0 ! m + m and 3-body D + ( s ) ! p + m + m , are considered here

  12. Ramsey interaction with transverse decay

    Institute of Scientific and Technical Information of China (English)

    Xucheng Wang; Huadong Cheng; Liang Liu

    2012-01-01

    The Ramsey fringe contrast of a pulsed optically pumped cold atom clock is strongly affected by the transverse decay of the atomic sample.This letter calculates the Ramsey fringe with focus on transverse decay,and analyzes the Ramsey fringe contrast with different transverse decay rates.By fitting the experimental data,we obtain the transverse decay rate in a cold atom sample at an approximate value of 30.5 s-1,which is much smaller than that in a cell.

  13. Radioactive Decays in Geant4

    OpenAIRE

    Hauf, Steffen; Kuster, Markus; Batič, Matej; Bell, Zane W.; Dieter H.H. Hoffmann; Lang, Philipp M.; Neff, Stephan; Pia, Maria Grazia; Weidenspointner, Georg; Zoglauer, Andreas

    2013-01-01

    The simulation of radioactive decays is a common task in Monte-Carlo systems such as Geant4. Usually, a system either uses an approach focusing on the simulations of every individual decay or an approach which simulates a large number of decays with a focus on correct overall statistics. The radioactive decay package presented in this work permits, for the first time, the use of both methods within the same simulation framework - Geant4. The accuracy of the statistical approach in our new pac...

  14. Study of GRB light curve decay indices in the afterglow phase

    CERN Document Server

    Del Vecchio, Roberta; Ostrowski, Michał

    2016-01-01

    In this work we study the distribution of temporal power-law decay indices, $\\alpha$, in the Gamma Ray Burst (GRB) afterglow phase, fitted for $176$ GRBs (139 long GRBs, 12 short GRBs {\\it with extended emission} and 25 X-Ray Flashes (XRFs)) with known redshifts. These indices are compared to the values of characteristic afterglow luminosity, $L_a$, the time, $T_a^*$, and the decay index, $\\alpha_W$, derived with global light curve fitting using the \\cite{willingale07} model. This model fitting yields similar distributions of $\\alpha_W$ to the fitted $\\alpha$, but for individual bursts a difference can be significant. Analysis of the ($\\alpha$, $L_a$) distribution reveals only a weak correlation of these quantities. However, we discovered a significant regular trend when studying GRB $\\alpha$ values along the $L_a$ versus $T_a^*$ (LT) distribution, with systematic variation of $\\alpha$ parameter distribution with luminosity for any selected $T_a^*$. We analyze this systematics with respect to the fitted LT co...

  15. 47 CFR 52.109 - Permanent cap on number reservations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Permanent cap on number reservations. 52.109... (CONTINUED) NUMBERING Toll Free Numbers § 52.109 Permanent cap on number reservations. (a) A Responsible Organization may have in reserve status, at any one time, either 2000 toll free numbers or 7.5 percent of...

  16. 47 CFR 61.41 - Price cap requirements generally.

    Science.gov (United States)

    2010-10-01

    ... party to a merger, acquisition, or similar transaction shall continue to be subject to price cap... no later than one year following the effective date of such merger, acquisition, or similar... subject to price cap regulation, as that term is defined in § 61.3(ee), which are involved in...

  17. ATLAS end-caps 
on the move

    CERN Multimedia

    2007-01-01

    Two delicate and spectacular transport operations have been performed for ATLAS in recent weeks: the first end-cap tracker was installed in its final position, and one of the huge end-caps of the toroid magnet was moved to the top of the experiment’s shaft.

  18. Preparing an ATLAS toroid magnet end-cap for lowering

    CERN Multimedia

    Claudia Marcelloni

    2007-01-01

    One of the two 13-m high toroid magnet end-caps for the ATLAS experiment being transported from the construction hall to the experimental area. The end-cap will be lowered into the ATLAS cavern and attached to an end of the detector.

  19. Regulating Telecommunications : Lessons from U.S. Price Cap Experience

    OpenAIRE

    Jeffrey H. Rohlfs

    1996-01-01

    Price cap regulation uses a formula, set in advance, to determine the price increases for a firm's services for a period of several years. During this period, the firm may keep all the benefits of its incremental productivity gains. Customers can also benefit because the price cap formula may cause prices to rise less rapidly during the period. The sharpened incentives created may encourag...

  20. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Derek R.; Schweiger, Michael J.; Riley, Brian J.; Pokorny, Richard; Hrma, Pavel R.

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of molten glass. Knowing the temperature profile within a cold cap will help determine its characteristics and relate them to the rate of glass production. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Since a direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed where the textural features in a laboratory-made cold cap with a high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. To correlate the temperature distribution to microstructures within the cold cap, microstructures were identified of individual feed samples that were heat treated to set temperatures between 400°C and 1200°C and quenched. The temperature distribution within the cold cap was then established by correlating cold-cap regions with the feed samples of nearly identical structures and was compared with the temperature profile from a mathematical model.