High spin states and isomeric decays in doubly-odd {sup 208}Fr

Energy Technology Data Exchange (ETDEWEB)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R. [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Saha, S., E-mail: satyajit.saha@saha.ac.i [Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhowmik, R.K.; Gehlot, J.; Muralithar, S.; Singh, R.P. [Inter University Accelerator Centre, New Delhi 110067 (India); Jnaneswari, G. [Department of Physics, Andhra University, Vishakhapatnam 530003 (India); Mukherjee, G. [Variable Energy Cyclotron Centre, Kolkata 700064 (India); Mukherjee, B. [Department of Physics, Visva Bharati, Santiniketan 731235 (India)

2010-10-15

Neutron deficient isotopes of francium (Z=87, N{approx}121-123) as excited nuclei were produced in the fusion-evaporation reaction: {sup 197}Au({sup 16}O, xn) {sup 213-x}Fr at 100 MeV. The {gamma} rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd {sup 208}Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E{sub {gamma}=}194(2) keV isomeric transition, known from earlier observations, was measured to be T{sub 1/2}=233(18) ns. A second isomeric transition at E{sub {gamma}=}383(2) keV and T{sub 1/2}=33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

An Energy Decaying Scheme for Nonlinear Dynamics of Shells

Science.gov (United States)

Bottasso, Carlo L.; Bauchau, Olivier A.; Choi, Jou-Young; Bushnell, Dennis M. (Technical Monitor)

2000-01-01

A novel integration scheme for nonlinear dynamics of geometrically exact shells is developed based on the inextensible director assumption. The new algorithm is designed so as to imply the strict decay of the system total mechanical energy at each time step, and consequently unconditional stability is achieved in the nonlinear regime. Furthermore, the scheme features tunable high frequency numerical damping and it is therefore stiffly accurate. The method is tested for a finite element spatial formulation of shells based on mixed interpolations of strain tensorial components and on a two-parameter representation of director rotations. The robustness of the, scheme is illustrated with the help of numerical examples.

Catalog of gamma-rays unplaced in radioactive decay schemes

International Nuclear Information System (INIS)

Narita, Tsutomu; Kitao, Kensuke.

1991-03-01

A catalog is made for gamma-rays emitted in decay of radioactive nuclides but not placed in their decay schemes. It consists of two tables. In Table 1, the number of these unplaced gamma-ray components by a nuclide is given together with the fraction of total intensity of these gamma-rays to that of all observed gamma-rays. In Table 2, the unplaced gamma-rays are arranged in order of increasing energy. Each line of this table contains the gamma-ray energy, intensity, nuclide identification, and energies and intensities of the most prominent gamma-rays from the decay of the radionuclides. This catalog is a compilation from Evaluated Nuclear Structure Data File (ENSDF) maintained by National Nuclear Data Center at Brookhaven National Laboratory, of at February 1990. (author)

Schemes of radioactive decay, its interpretations in the scope of the radiological protection

International Nuclear Information System (INIS)

Mohamad, N.; Caro, R.A.; Bergoc, R.M.

1998-01-01

Full text: In our teaching experience we have verified that the interpretation of the symbols of radioactive decay schemes is one of the most difficult subject in the study of radioisotope methodologies for almost all professionals, and specially for those who have no solid background in mathematics or physics. The correct interpretation of decay schemes has fundamental importance for the proper election of measurement conditions and for performing the dosimetric and shielding calculations. Nuclides employed in Nuclear Medicine and Biomedicine are beta, gamma or beta/gamma emitters. Interpretation of decay schemes of beta emitters, by β + , β - or electronic capture are not difficult. In gamma emitting nuclides it is frequent that a particular level of energy is de-excited through more than one gamma transition of a given percentage and energy. On the other hand, it is also frequent that conversion electrons are emitted together with gamma photons, the proportion of which is usually given as the conversion factor, e/γ. The fraction of emitted photons is calculated as: 1 / [1+ (e/γ)], whereas the fraction of emitted conversion electrons is equal to: (e/γ) / [1+ (e/γ)]. Special attention should be given to the post-accommodation mechanism after disintegration in which orbital vacancies are produced: electron conversion or electron capture, in which the emission of X-rays and Auger electrons occur. All this information should be taken into account for the correct choice of measurement conditions, as well as internal and external dose calculations. In the present work we describe the analysis and interpretation of disintegration schemes in general and that of the most employed nuclides in Nuclear Medicine and Biomedicine. (author) [es

Track reconstruction of normal muon decays in the LAMPF TPC: one working scheme

International Nuclear Information System (INIS)

McKee, R.J.

1983-01-01

A working scheme for track reconstruction of normal muon decays in the LAMPF TPC is here outlined. Muon tracks stopping in the TPC and helical electron tracks from muon decay are both identified and fitted for complete event reconstruction. Because of certain geometrical characteristics of the TPC, novel techniques are deployed to find the tracks. Normal road tracing methods do not work reliably; they are replaced by, among other things, a random search technique that locates the helix's planar projection and a carefully worked-out method for correctly putting each coordinate on its proper turn in the helix

Method and program for decay scheme reconstruction based on formal logical analysis of gamma-gamma coincidence matrix

International Nuclear Information System (INIS)

Adam, J.; Tsupko-Sitnikov, V.M.

1996-01-01

A new, rigorously substantiated approach to construction of decay schemes on the basis of γ-γ coincidence data is described. Complete decay modes (concrete cascades of transitions from excited to the ground-state of a nucleus excited in a decay or a reaction) and continuity regions in complete modes (regions of successive transitions) are isolated by logical operations with rows (columns) of a symmetrical coincidence matrix where rows (columns) correspond to energies of coinciding transitions and matrix elements are unities and zeros, depending on the presence or absence of the given coincidence. To reject false complete modes and continuity regions arising from incompleteness of the coincidence data and errors in them, energy selection is introduced for complete modes and continuity regions, which demands that total energy of their constituent transitions should be equal to total energy of some other complete modes and continuity regions and to the energies of singles. With the continuity regions found, it is possible to order transitions in the selected complete modes and to algorithmize matching of complete modes into a decay scheme. 10 refs., 3 figs

Studies of α-spectra in 221Fr, 217At, 213Bi and 213Po decays

International Nuclear Information System (INIS)

Chumin, V.G.; Fominykh, V.I.; Furyaev, T.A.; Gromov, K.Ya.; Jabber, J.K.; Kalyapkin, K.V.; Kudrya, S.A.; Tsupko-Sitnikov, V.V.

1997-01-01

The alpha-recoil phenomenon is used to gain data on the weak components of the α-spectra of the nuclides from the 225 Ac equilibrium chain. It is established that there is no experimental basis for introducing the 450 keV level of 213 Bi in the 217 At decay and the 868 keV level of 209 Tl in the 213 Bi decay. Excitation of the 759 keV level in the 217 At decay is confirmed. The intensities of the 221 Fr, 217 At and 213 Bi β - -decay are measured

Scalar correlator, Higgs decay into quarks, and scheme variations of the QCD coupling

Energy Technology Data Exchange (ETDEWEB)

Jamin, Matthias [IFAE, BIST,Campus UAB, 08193 Bellaterra (Barcelona) (Spain); ICREA,Pg. Lluís Companys 23, 08010 Barcelona (Spain); Miravitllas, Ramon [IFAE, BIST,Campus UAB, 08193 Bellaterra (Barcelona) (Spain)

2016-10-12

In this work, the perturbative QCD series of the scalar correlation function Ψ(s) is investigated. Besides /rm ImΨ(s), which is relevant for Higgs decay into quarks, two other physical correlators, Ψ{sup ″}(s) and D{sup L}(s), have been employed in QCD applications like quark mass determinations or hadronic τ decays. D{sup L}(s) suffers from large higher-order corrections and, by resorting to the large-β{sub 0} approximation, it is shown that this is related to a spurious renormalon ambiguity at u=1. Hence, this correlator should be avoided in phenomenological analyses. Moreover, it turns out advantageous to express the quark mass factor, introduced to make the scalar current renormalisation group invariant, in terms of the renormalisation invariant quark mass m̂{sub q}. To further study the behaviour of the perturbative expansion, we introduce a QCD coupling α̂{sub s}, whose running is explicitly renormalisation scheme independent. The scheme dependence of α̂{sub s} is parametrised by a single parameter C, being related to transformations of the QCD scale parameter Λ. It is demonstrated that appropriate choices of C lead to a substantial improvement in the behaviour of the perturbative series for Ψ{sup ″}(s) and /rm ImΨ(s).

The investigation of the decay of the deformed 167Yb, 164Tm, 225Ac, 221Fr nuclei. Beta-spectrograph with positional-sensitive detector

International Nuclear Information System (INIS)

Butabaev, Yu.S.

1994-01-01

The decay of the deformed 167 Yb, 164 Tm, 225 Ac, 221 Fr nuclei is investigated in this work. For 167 Yb and 164 Tm decays the specters of the conversion electrons were measured. 32 γ-transitions were found for 167 Yb decay, 6 of which were found for the first time. The multipolarities for 9 γ-transitions were found. For 164 Tm decay 23 new γ-transitions were found. The theoretical investigations of the collective states in the nucleus were carried out. Octupole-rotatory line with k=1 - was found in the measurement of conversion electrons specters of the short-life nuclei. Device' nonlinearity was 0,04%. Resolution was Δβρ/βρ 0,11%. Effective light yield was 1-2 %. The decay of 225 Ac and 221 Fr nuclei were investigated. The investigations of α-γ -coincidence, α-γ - rays were carried out. 24 new γ -transitions for 225 Ac and 13 ones for 221 Fr were found. The new levels and their intensities were defined more precisely. Intensity balance calculations were carried out and the full populations of the nuclear levels were calculated. (author). 3 tabs.; 10 figs

Charged Higgs production from polarized top-quark decay in the 2HDM considering the general-mass variable-flavor-number scheme

Science.gov (United States)

Abbaspour, S.; Mohammad Moosavi Nejad, S.

2018-05-01

Charged Higgs bosons are predicted by some non-minimal Higgs scenarios, such as models containing Higgs triplets and two-Higgs-doublet models, so that the experimental observation of these bosons would indicate physics beyond the Standard Model. In the present work, we introduce a channel to indirect search for the charged Higgses through the hadronic decay of polarized top quarks where a top quark decays into a charged Higgs H+ and a bottom-flavored meson B via the hadronization process of the produced bottom quark, t (↑) →H+ + b (→ B + jet). To obtain the energy spectrum of produced B-mesons we present, for the first time, an analytical expression for the O (αs) corrections to the differential decay width of the process t →H+ b in presence of a massive b-quark in the General-Mass Variable-Flavor-Number (GM-VFN) scheme. We find that the most reliable predictions for the B-hadron energy spectrum are made in the GM-VFN scheme, specifically, when the Type-II 2HDM scenario is concerned.

Level Scheme of {sup 223}Fr; Estudio del esquema de niveles del {sup 223}Fr

Energy Technology Data Exchange (ETDEWEB)

Gaeta, R; Gonzalez, L; Roldan, C

1972-07-01

A study has been made of the decay of {sup 227}Ac at levels of {sub 223}Fr, means of alpha Spectrometers of Si barrier detector and gamma Spectrometers of Ge(Li). The rotational bands 1/2-(541 {down_arrow}), 1/2-(530 {up_arrow}) and 3/2-(532 {down_arrow}) have been identified, as well as two octupolar bands associated with the fundamental one. The results obtained indicate that the unified model is applicable in this intermediate zone of the nuclide chart. (Author) 150 refs.

Application of the Broad Energy Germanium detector: A technique for elucidating β-decay schemes which involve daughter nuclei with very low energy excited states

Energy Technology Data Exchange (ETDEWEB)

Venhart, M., E-mail: martin.venhart@savba.sk [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Wood, J.L. [Department of Physics, Georgia Institute of Technology, Atlanta GA 30332 (United States); Boston, A.J. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Cocolios, T.E. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); KU Leuven, Instituut voor Kern, en Stralingsfysica, B-3001 Leuven (Belgium); Harkness-Brennan, L.J.; Herzberg, R.-D.; Joss, D.T.; Judson, D.S. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Kliman, J.; Matoušek, V. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia); Motyčák, Š. [Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, SK-812 19 Bratislava (Slovakia); Page, R.D.; Patel, A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Petrík, K.; Sedlák, M.; Veselský, M. [Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava (Slovakia)

2017-03-21

A technique for elucidating β-decay schemes of isotopes with a large density of states at low excitation energy has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique is demonstrated using the example of {sup 183}Hg decay. Mass-separated samples of {sup 183}Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed γ-ray energies to be determined with a precision of a few tens of eV, which was sufficient for the analysis of the Rydberg-Ritz combinations (in conjunction with γ-γ coincidences) in the level scheme. The timestamped structure of the data was used for unambiguous separation of γ rays arising from the decay of {sup 183}Hg from those due to the daughter decays.

Decay scheme of the U235

International Nuclear Information System (INIS)

Gaeta, R.

1965-01-01

A study of the Th 2 31 excited levels from the alpha decay of the U 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 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

Level and decay schemes of even-A Se and Ge isotopes from (n,n'γ) reaction studies

Energy Technology Data Exchange (ETDEWEB)

Sigaud, J.; Patin, Y.; McEllistrem, M. T.; Haouat, G.; Lachkar, J.

1975-06-01

The energy levels and the decay schemes of {sup 76}Se, {sup 78}Se, {sup 80}Se, {sup 82}Se and {sup 76}Ge have been studied through the measurements of (n,n'γ) differential cross sections. Gamma-ray excitation functions have been measured between 2.0- and 4.1-MeV incident neutron energy, and angular distribution have been observed for all of these isotopes.

238Pu - Comments on Evaluation of Decay Data

International Nuclear Information System (INIS)

Chechev, V. P.

2013-01-01

This evaluation was done originally in March 2003, corrected in June 2004, and then updated in June 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2007Br04. Some expected weak gamma-ray transitions were not observed directly in 238 Pu α-decay but have been adopted from decay of 234 Pa and 234 Np

Beta decay of 31,32Na and 31Mg

International Nuclear Information System (INIS)

Klotz, G.; Baumann, P.; Bounajma, M.; Huck, A.; Knipper, A.; Walter, G.; Poves, A.; Retamosa, J.

1993-01-01

31,32 Na and 31 Mg beta decays were studied at the CERN on-line mass separator ISOLDE by gamma, gamma-gamma and neutron-gamma measurements. In the 31 Na decay, the assignment of previously reported γ transitions and the observation of a new level at 3760 keV lead to a revised decay scheme. In the 31 Mg → 31 Al decay, a new decay scheme involves ten β branches and three states are reported for the first time. New spectroscopic results have been obtained in the 32 Na β - decay. A previously non-interpreted 1436 keV γ ray is now assigned in the 32 Mg scheme. (author) 33 refs., 16 figs., 12 tabs

Strong decays of sc-bar mesons in the covariant oscillator quark model with the U tilde (4)DS x O(3, 1)L-classification scheme

International Nuclear Information System (INIS)

Maeda, Tomohito; Yamada, Kenji; Oda, Masuho; Ishida, Shin

2010-01-01

We investigate the strong decays with one pseudoscalar emission of charmed strange mesons in the covariant oscillator quark model. The wave functions of composite sc-bar mesons are constructed as the irreducible representations of the U tilde (4) DS xO(3,1) L . Through the observed mass and results of decay study we discuss a novel assignment of observed charmed strange mesons from the viewpoint of the U tilde (4) DS x O(3,1) L -classification scheme. It is shown that D s0 * (2317) and D s1 (2460) are consistently explained as ground state chiralons, appeared in the U tilde (4) DS xO(3,1) L scheme. Furthermore, it is also found that recently-observed D s1 * (2710) could be described as first excited state chiralon. (author)

SU(6), baryonic decays of B-mesons and CP

International Nuclear Information System (INIS)

Wu, D.

1990-01-01

In this paper the four fermion weak decay Hamiltonian is expressed in terms of quark-antiquark creation operators with specific spin orientations. Then the SU(6) symmetry of the strong interactions among light quarks is imposed to find 8 invariant decay amplitudes for two body charmful baryonic decays of the B-mesons, 3 S-waves, 4 P- waves and 1 D-wave. Λ c branching ratio and some exclusive branching ratios are calculated based on the assumption of two body dominance in baryonic decay modes. Results on two body mesonic decays are also given. Relation between the SU(6) scheme and the quark diagram scheme is discussed

Quark-diagram analysis of charmed-baryon decays

International Nuclear Information System (INIS)

Kohara, Y.

1991-01-01

The Cabibbo-allowed two-body nonleptonic decays of charmed baryons to a SU(3)-octet (or -decuplet) baryon and a pseudoscalar meson are examined on the basis of the quark-diagram scheme. Some relations among the decay amplitudes or rates of various decay modes are derived. The decays of Ξ c + to a decuplet baryon are forbidden

β decay of Na32

Science.gov (United States)

Mattoon, C. M.; Sarazin, F.; Hackman, G.; Cunningham, E. S.; Austin, R. A. E.; Ball, G. C.; Chakrawarthy, R. S.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Koopmans, K. A.; Leslie, J. R.; Phillips, A. A.; Schumaker, M. A.; Scraggs, H. C.; Schwarzenberg, J.; Smith, M. B.; Svensson, C. E.; Waddington, J. C.; Walker, P. M.; Washbrook, B.; Zganjar, E.

2007-01-01

The β-decay of Na32 has been studied using β-γ coincidences. New transitions and levels are tentatively placed in the level scheme of Mg32 from an analysis of γ-γ and β-γ-γ coincidences. The observation of the indirect feeding of the 2321 keV state in Mg32 removes some restrictions previously placed on the spin assignment for this state. No evidence of a state at 2117 keV in Mg32 is found. Previously unobserved weak transitions up to 5.4 MeV were recorded but could not be placed in the decay scheme of Na32.

Reaction schemes of immunoanalysis

International Nuclear Information System (INIS)

Delaage, M.; Barbet, J.

1991-01-01

The authors apply a general theory for multiple equilibria to the reaction schemes of immunoanalysis, competition and sandwich. This approach allows the manufacturer to optimize the system and provide the user with interpolation functions for the standard curve and its first derivative as well, thus giving access to variance [fr

Four pion decay modes of the f0(1500) resonance

International Nuclear Information System (INIS)

Vinh Mau, R.; Strohmeier-Presicek, M.; Gutsche, T.; Faessler, A.

1999-01-01

We investigate the two-body decay modes ρρ, ππ * (1300) and σσ of the f 0 (1500), all leading to the four pion decay channel, in a three-state mixing scheme, where the f 0 (1500) is a mixture of the lowest lying scalar glueball with the nearby isoscalar states of the 0 ++ Q Q-bar nonet. In the leading order of this scheme, the decay mechanism of the f 0 (1500) proceeds dominantly via its quarkonium components, which can be described in the framework of the 3 P 0 pair creation model. We predict the hierarchy of decay branching ratios B with B(ρρ) ≥ B(ππ) ≥ B(σσ) > B(ππ * ), providing a key signature of the proposed mixing scheme in this leading order approach. (authors)

Decay schemes of the radioactive nuclei A = 225 to 229. Skhemy raspada radioaktivnykh yader A = 225 - 229

Energy Technology Data Exchange (ETDEWEB)

Dzhelepov, B S; Ivanov, R B; Mikhailova, M A

1976-01-01

This monograph is devoted to properties of atomic nuclei with mass numbers A = 225 to 229. The book collects and systematizes all of the experimental data characterizing properties of radioactive isotopes: information concerning masses of nuclei, magnetic and electric moments, lifetimes of nuclear states, the most reliable information on characteristics of radiations, quantum characteristics of levels and other properties of the studied nuclei. On basis of a critical analysis of the totality of information, decay schemes of radioactive nuclei with mass numbers A = 225 to 229 were constructed, as well as the series of excited states of the isotopes which lie in this region of nuclei.

Genetic effects of decay by electron capture of radionuclides in yeasts cell

International Nuclear Information System (INIS)

Gracheva, L.M.; Korolev, V.G.

1984-01-01

Regularities of genetic effect on the yeast cell Saccharomyces cerevisiae, incorporated radionuclides decaying according to the scheme of k-capture- 7 Be, 54 Mn, 85 Sr are studied. It is known that this type of decay models the ionization of internal electron shells of atoms which is most probable when a cell is affected by external ionizing radiation. It is shown that the decay of radionuclides connecting with a DNA molecule in a cell according to the scheme of D-capture brings about a strong lethal effect. The relative mutagenic efficiency is much lower than that for gamma-radiation and many radionuclides decaying according to the scheme of B-decay. In the mutation spectrum induced by these radionuclides the increase in the number of mutations of the reading frame shift type is observed

Decay of 83Sr

International Nuclear Information System (INIS)

Yu Xiaohan; Shi Shuanghui; Gu Jiahui

1997-01-01

The decay of 83 Sr was reinvestigated using γ singles and γ-γ-t coincidence measurement. A new level scheme of Rb, which contains 41 excited levels and about 180 transitions, is constructed. 19 new levels were added to the old level scheme and 8 formerly adopted levels were denied. A new data set of branching ratio, log(ft) value and spin parity was obtained

Beta decay and strength distributions

International Nuclear Information System (INIS)

Hardy, J.C.

1980-01-01

With the increasing accessibility of nuclei far from stability, experimenters find themselves faced more and more often with complex β-decay schemes: nuclei with over 5 MeV of β-decay energy, exhibiting hundreds and perhaps thousands of transitions. A detailed level-by-level exposition of such schemes - for example, by studying β-delayed γ-rays - is at best prohibitively time consuming, and at worst actually impossible with current techniques. Furthermore, even if reliable schemes are obtained experimentally, their confrontation with theory is severely limited by the absence of theories sufficiently complete to account for such complex spectra. At best, it is the details of the first few excited states and the general features of the rest that are useful for comparison. From both points of view, experimental and theoretical, there is strong motivation to find a broader perspective, emphasizing these general features without being overwhelmed by a proliferation of detail

β decay studies of n-rich Cs isotopes with the ISOLDE Decay Station

Science.gov (United States)

Lică, R.; Benzoni, G.; Morales, A. I.; Borge, M. J. G.; Fraile, L. M.; Mach, H.; Madurga, M.; Sotty, C.; Vedia, V.; De Witte, H.; Benito, J.; Berry, T.; Blasi, N.; Bracco, A.; Camera, F.; Ceruti, S.; Charviakova, V.; Cieplicka-Oryńczak, N.; Costache, C.; Crespi, F. C. L.; Creswell, J.; Fernández-Martínez, G.; Fynbo, H.; Greenlees, P.; Homm, I.; Huyse, M.; Jolie, J.; Karayonchev, V.; Köster, U.; Konki, J.; Kröll, T.; Kurcewicz, J.; Kurtukian-Nieto, T.; Lazarus, I.; Leoni, S.; Lund, M.; Marginean, N.; Marginean, R.; Mihai, C.; Mihai, R.; Negret, A.; Orduz, A.; Patyk, Z.; Pascu, S.; Pucknell, V.; Rahkila, P.; Regis, J. M.; Rotaru, F.; Saed-Sami, N.; Sánchez-Tembleque, V.; Stanoiu, M.; Tengblad, O.; Thuerauf, M.; Turturica, A.; Van Duppen, P.; Warr, N.

2017-05-01

Neutron-rich Ba isotopes are expected to exhibit octupolar correlations, reaching their maximum in isotopes around mass A = 146. The odd-A neutron-rich members of this isotopic chain show typical patterns related to non-axially symmetric shapes, which are however less marked compared to even-A ones, pointing to a major contribution from vibrations. In the present paper we present results from a recent study focused on 148-150Cs β-decay performed at the ISOLDE Decay Station equipped with fast-timing detectors. A detailed analysis of the measured decay half-lives and decay scheme of 149Ba is presented, giving a first insight in the structure of this neutron-rich nucleus.

Observation of excited states and isomeric decays in doubly-odd 208Fr

International Nuclear Information System (INIS)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R.K.; Gehlot, J.; Jnaneswari, G.; Muralithar, S.; Singh, R.P.; Mukherjee, B.; Mukherjee, G.

2009-01-01

The nuclei near the doubly magic 208 Pb are predicted to exhibit various interesting structural phenomena, one of which is a wealth of isomerism. However, a detailed study of high spin states of 211, 212, 213 Fr has already been done. Structure of such trans-Lead nuclei can be interpreted in terms of the shell model states, and the high spin states of these nuclei are interpreted. One of the major interests in the spectroscopic investigation of these nuclei is the role played by the i 13/2 state in creating isomeric levels which decay through transitions of higher muiltipolarity, or are hindered by the close proximity of the levels below. A systematic study of these nuclei will possibly reveal many other interesting structural features

Decay of sup 7 sup 6 As

CERN Document Server

Camargo, S P D; Medeiros, J A G; Kenchian, G; Cruz, M T F

1998-01-01

The level structure of sup 7 sup 6 Se has been investigated by studying the gamma-rays emitted following the beta sup - decay of sup 7 sup 6 As. The energies and relative intensities of 45 gamma-rays have been determined with a better overall precision than previously. Two new transitions with 528.2 and 1232.4 keV have been found and placed in the level scheme. A new level, at 1791.5 keV excitation energy, is proposed. Seven transitions and three levels previously attributed to this decay scheme were not confirmed.

Non-charm hadronic decays of bottom baryons

International Nuclear Information System (INIS)

Kohara, Y.

1999-01-01

Two-body decay amplitudes of antitriplet bottom baryons Λ 0b , Θ 0 b and Θ -b to a decuplet baryon and a pseudoscalar meson are analyzed on the basis of the quark diagram scheme. Relations among the various decay rates to decuplet baryons are derived

Beta decay of 22O

International Nuclear Information System (INIS)

Hubert, F.; Dufour, J.P.; Moral, R. Del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

1991-01-01

22 O nuclei were produced as fragments of a 60 MeV/n 40 Ar beam interacting with a thick Be target. They were selected from all the produced nuclei with the LISE separator. γ spectra in coincidence with the β decay were measured. Partial decay scheme of 22 O is given. Similarities between experiments and calculations are discussed. (G.P.) 10 refs.; 3 figs

Measurement of W-Helicity Fractions in $t\\bar{t}$ decays and Search for Exotic Dihiggs Production in the $b\\bar{b}WW^*$ Decay Channel Using the ATLAS Detector

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00375951

Two analyses using the ATLAS detector at the Large Hadron Collider are presented. The first analysis uses 20.2 fb$^{-1}$ of data collected at a center of mass energy of $\\sqrt{s}=8$ TeV to produce a measurement of the helicity fractions of $W$ bosons produced in the semileptonic decays of top quark pairs. The helicity fractions are measured using both the leptonically and hadronically decaying $W$ bosons. The fractions measured using the leptonic $W$ are the most precise values obtained to date, and the fractions obtained using the $W$ decaying to quarks represent the first direct measurement using the hadronic $W$ decays in top quark pairs. The fitted fractions of longitudinal, left-handed, and right-handed polarization states using the leptonic $W$ are $F_{0}$ = $0.709 \\pm 0.019$, $F_{L}$ = $0.299 \\pm 0.015$, and $F_{R}$ = $−0.008 \\pm 0.014$ respectively. These results are in agreement with the Standard Model prediction of $F_{0}$ = 0.687 $\\pm$ 0.005, $F_{L}$ = 0.311 $\\pm$ 0.005, and $F_{R}$ = 0.0017 $\\pm...

The decay of 61Cu nucleus

International Nuclear Information System (INIS)

Zheng Wanhui; Gu Jiahui; Zhu Jiabi; Wang Gongqing

1988-01-01

The decay of 61 Cu nucleus has been investigated with Ge(Li) and H p Ge detector, semiconductor electron spectrometer and Ge(Li)-NaI γ-γ coincidence spectrometer. 35 γrays from 12 excited levels have been found. The single and coincidence spectra show that 545 keV, 1019keV γ fays and 1019keV energy level are wrong which appear in the 61 Cu decay scheme carried in > (the 7th edition 1978). the halflife time of 61 Cu nucleus and the internal conversion coefficient for 67 keV γ-transition are found to be T 1/2 =207.7±1.6min and α=0.12±0.01 respectively and then a decay scheme is proposed. In this paper more attention ia paid to discussing the energy levels of 1014, 1019, and 1997 keV as well as some weak γ rays

Three-body Supersymmetric Top Decays

CERN Document Server

Belyaev, A; Lola, S; Belyaev, Alexander; Ellis, John; Lola, Smaragda

2000-01-01

We discuss three-body supersymmetric top decays, in schemes both with andwithout R-parity conservation, assuming that sfermion masses are larger thanm_t. We find that MSSM top decays into chargino/neutralino pairs have a strongkinematic suppression in the region of the supersymmetric parameter spaceconsistent with the LEP limits, with a decay width =< 10^{-5} GeV. MSSM topdecays into neutralino pairs have less kinematical suppression, but require aflavour-changing vertex, and are likely to have a smaller rate. On the otherhand, R-violating decays to single charginos, neutralinos and conventionalfermions can be larger for values of the R-violating couplings still permittedby other upper limits. The cascade decays of the charginos and neutralinos maylead to spectacular signals with explicit lepton-number violation, such aslike-sign lepton events.

Spectroscopy of nuclei 215Fr and 219 Ac: a contribution to the study of the nuclear structure of light actinides

International Nuclear Information System (INIS)

Khazrouni, S.

1985-06-01

Using α-particle and γ-ray spectroscopy, it has been possible to establish the high spin pattern in 215 Fr and propose a decay scheme up to I π = (47/2 + ) containing six isomeric states. These results are interpreted using the recent version of the deformed Woods-Saxon model and the Strutinsky normalisation technique. A similar study in 219 Ac has revealed the existence of two quasi-bands each formed of states of alternating parity and connected by strong E1 transitions. This data for 219 Ac fits better with the stable octupole deformation model, mainly because of the high-spin parity doublets observed for the first time, than with the α-cluster model [fr

Double beta decay: introduction, motivations and last results

International Nuclear Information System (INIS)

Hubert, P.

1986-01-01

The double β decay process is the direct desexcitation from a nucleus (Z,A) to a nucleus (Z+2, A). Since long time ago, study of this process has been recognized as a very sensitive test of the lepton number non-conservation and therefore the double β decay process is strongly connected to the neutrino properties. This review starts with the main definitions and main motivations for such studies. Then the different experiments actually running and the most recent experimental results are exposed [fr

Evolution system study of a generalized scheme of relativistic magnetohydrodynamic

International Nuclear Information System (INIS)

Mahjoub, Bechir.

1977-01-01

A generalized scheme of relativistic magnetohydrodynamics is studied with a thermodynamical differential relation proposed by Fokker; this scheme takes account of interaction between the fluid and the magnetic field. Taking account of an integrability condition of this relation, the evolution system corresponding to this scheme is identical to the one corresponding to the usual scheme; it has the same characteristics; it is non-strictly hyperbolic with the same hypothesis of compressibility and it has, with respect to the Cauchy problem, an unique solution in a Gevrey class of index α=3/2 [fr

Spectroscopy of element 115 decay chains

Energy Technology Data Exchange (ETDEWEB)

Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2013-01-01

A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

Schemes for Greenberger-Horne-Zeilinger and cluster state preparation

International Nuclear Information System (INIS)

Song Jie; Xia Yan; Song Heshan

2008-01-01

Schemes to generate Greenberger-Horne-Zeilinger (GHZ) and cluster states of three atoms are proposed in a two-mode cavity. The advantages of the schemes are their robustness against decoherence due to spontaneous emission of the excited states and decay of the cavity modes. Moreover, the schemes can be generalized to generate N-atom entangled states

Spectroscopy of element 115 decay chains.

Science.gov (United States)

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

2013-09-13

A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

Study on the eγ coincidences in the 169Lu decay

International Nuclear Information System (INIS)

Batsev, S.; Bonch-Osmolovskaya, N.A.; Budzyak, A.; Kuznetsov, V.V.; Usmanov, R.R.

1979-01-01

The 169 Lu→ 169 Yb decay scheme was analyzed on the basis of measurements of eγ coincidence. The 169 Lu sources were obtained by irradiating a tantalum target by 660 MeV protons. The eγ-coincidence spectra were measured by an ironless β-spectrometer with a toroidal magnetic field and a detector. The γ-ray and eγ-coincidence spectra were processed by a computer. The results of processing the 169 Lu coincidence spectra are tabulated. No excited states of 169 Yb not confirmed by γγ and eγ coincidences (except for the head level of the 3/2 + (651) 720 keV band) remain in the 169 Lu decay scheme proposed. Weak transitions with the total intensity of no more than 3.3% per a 169 Lu decay have remained unarranged, they should discharge weakly excited levels of 169 Yb. Probabilities of the 169 Yb level population per a 169 Lu decay and the corresponding values of probabilities of transitions in them are presented. As a whole, the 169 Lu decay scheme involves 60 levels, 31 states of them are new

New information on the $\\beta$-decay of $^{11}$Li from Doppler broadened $\\gamma$-lines

CERN Document Server

Fynbo, H O U; Cederkäll, J; Courtin, S; Dessagne, P; Jonson, B; Le Scornet, G; Nilsson, T; Nyman, G H; Poirier, E; Riisager, K; Tengblad, O; Wilhelmsen, K

2004-01-01

The $\\gamma$-ray spectrum following $\\beta$-decay of $^{11}$Li has been remeasured at the ISOLDE facility at CERN. Two new transitions were observed through the use of large Ge-detectors. Most $\\gamma$-decays will follow P-delayed neutron emission. Information on the energy of the neutron is derived from analysis of the $\\gamma$-line-shape and used to construct a partial decay scheme for $^{11}$Li. Lifetime values for the 1$^{-}$ and 2$^{-}$ levels in $^{10}$Be are also derived. A new partial decay scheme is presented. (43 refs).

JENDL FP decay data file 2000 and the beta-decay theory

International Nuclear Information System (INIS)

Yoshida, Tadashi; Katakura, Jun Ichi; Tachibana, Takahiro

2002-01-01

JENDL FP Decay Data File 2000 has been developed as one of the special purpose files of the Japanese Evaluated Nuclear Data Library (JENDL), which constitutes a versatile nuclear data basis for science and technology. In the format of ENDF-6 this file includes the decay data for 1087 unstable fission product (FP) nuclides and 142 stable nuclides as their daughters. The primary purpose of this file is to use in the summation calculation of FP decay heat, which plays a critical role in nuclear safety analysis; the loss-of-coolant accident analysis of reactors, for example. The data for a given nuclide are its decay modes, the Q value, the branching ratios, the average energies released in the form of beta- and gamma-rays per decay, and their spectral data. The primary source of the decay data adopted here is the ENSDF (Evaluated Nuclear Structure Data File). The data in ENSDF, however, cover only the measured values. The data of the short-lived nuclides, which are essential for the decay heat calculations at short cooling times, are often fully lacking or incomplete even if they exist. This is mainly because of their short half-life nature. For such nuclides a theoretical model calculation is applied in order to fill the gaps between the true and the experimentally known decay schemes. In practice we have to predict the average decay energies and the spectral data for a lot of short-lived FPs by use of beta-decay theories. Thus the beta-decay theory plays a very important role in generating the FP decay data file

The Re-evaluation of 84Rb decay data

International Nuclear Information System (INIS)

Huang Xiaolong; Zhou Chunmei

1996-01-01

The 84 Rb is an important radionuclide and its decay data are fundamental data in nuclear applications. The decay data for 84 Rb were re-evaluated. The energies and intensities of γ rays and their internal conversion coefficients, energies and intensities of Auger electrons, conversion electrons and x-rays, were recommended. The decay scheme was also given. The balance of radiation rays intensities and energies was checked. (9 tabs., 2 figs.)

Proton Decay including extra Z0 bosons

International Nuclear Information System (INIS)

Li Tiezhong

1988-06-01

There exists an apparent discrepancy between proton decay experiment and simplest SU(5) prediction. Author suggested a scheme: if there exists an extra Z 0 boson then the experimental value of the proton decay may be caluclated from GUT and the good results of SU(5) can be preserved. The increasing fermions will be not bizarre

ENDF/B fission product decay data

International Nuclear Information System (INIS)

Rose, P.F.; Burrows, T.W.

1976-08-01

The fission product data have been organized by A-chains in order of ascending A from A = 72 to A = 167. The heading page is followed by more detailed information on the individual members of the chain in order of increasing Z and decreasing metastable state. The detailed information for each member includes the ENDF/B-IV File 1 comments and references if available and applicable to the decay data. Following the comments is a decay scheme of the nuclide tabulating the quantities T/sub 1 / 2 /, Q, branching ratio (BR), (E/sub γ/), (E/sub β/), and (E/sub α/). Uncertainties are given if available in the file. Independent fission yields are given, as well as thermal cross sections and resonance integrals as obtained from ENDF/B-IV. All energies listed in this publication are in keV, and all branching ratios (BR) sum to unity. If there are spectra in the decay data file, the decay scheme is followed by tables of photon, particle, and characteristic radiation. For cases in which the multipolarities could be obtained from the file the tables also contain information on x-rays, conversion electrons, and Auger electrons. Associated with the photon and particle radiation tables are the appropriate average energies per decay for each type of radiation, including neutrino radiation

(EC+β+) decay of 130Ce

International Nuclear Information System (INIS)

Xu Shuwei; Zhang Tianmei; Xie Yuanxiang; Ma Ruichang; Ge Yuanxiu; Guo Yingxiang; Wang Chunfang; Li Zhankui; Guo Bing; Xing Jianping; Guo Tianrui; Zhu Shaofei; Xu Wang; Du Jinzhou

1996-01-01

The nuclide 130 Ce was produced by a ( 16 O, 4n) reaction on an enriched 118 Sn target. Reaction products were transported to a shielded location by using a helium-jet tape transport system. A 22.9 min activity in chemically separated cerium sample was identified as 130 Ce. The (EC+β + ) decay scheme of 130 Ce was proposed for the first time. This scheme includes 108 γ-lines, 107 γ-lines among them being new. More than 13 1 + low-lying states of 130 La are populated in the decay of 130 Ce. Two new isomers with half-life of 77±10 ns and 17±5 ns were observed by means of delayed γ-γ coincidence measurements. (orig.). With 5 figs., 3 tabs

Detailed α -decay study of 180Tl

Science.gov (United States)

Andel, B.; Andreyev, A. N.; Antalic, S.; Barzakh, A.; Bree, N.; Cocolios, T. E.; Comas, V. F.; Diriken, J.; Elseviers, J.; Fedorov, D. V.; Fedosseev, V. N.; Franchoo, S.; Ghys, L.; Heredia, J. A.; Huyse, M.; Ivanov, O.; Köster, U.; Liberati, V.; Marsh, B. A.; Nishio, K.; Page, R. D.; Patronis, N.; Seliverstov, M. D.; Tsekhanovich, I.; Van den Bergh, P.; Van De Walle, J.; Van Duppen, P.; Venhart, M.; Vermote, S.; Veselský, M.; Wagemans, C.

2017-11-01

A detailed α -decay spectroscopy study of 180Tl has been performed at ISOLDE (CERN). Z -selective ionization by the Resonance Ionization Laser Ion Source (RILIS) coupled to mass separation provided a high-purity beam of 180Tl. Fine-structure α decays to excited levels in the daughter 176Au were identified and an α -decay scheme of 180Tl was constructed based on an analysis of α -γ and α -γ -γ coincidences. Multipolarities of several γ -ray transitions deexciting levels in 176Au were determined. Based on the analysis of reduced α -decay widths, it was found that all α decays are hindered, which signifies a change of configuration between the parent and all daughter states.

Beta decay is 151Pr into levels in 151Nd

International Nuclear Information System (INIS)

Shibata, Michihiro; Ikuta, Tomohiko; Taniguchi, Akihiro

1994-01-01

The β-decay of 59 151 Pr 92 to the levels in 60 151 Nd 91 has been studied from the fission products of 235 U using an on-line isotope separator (KUR-ISOL). Gamma-rays and conversion electrons have been measured. Conversion coefficients have been determined for the first time. The precise decay scheme is proposed up to 2430 keV. The newly observed 65 γ-rays and 16 levels are incorporated in it. The deduced level scheme of 151 Nd was compared to the calculated level scheme on the basis of the rotation-vibration coupling model with a Nilsson potential. Low-lying levels were well reproduced by this model. (author)

Beta decays of 126Cd and 126In to levels in 126In and 126Sn

International Nuclear Information System (INIS)

Gartner, M.L.

1979-01-01

A study of the beta decays of 126 Cd and 126 In using the TRISTAN on-line isotope separator facility is reported. Gamma-ray singles measurements were made for both decays usng Ge(Li) and LEPS (low energy photon spectrometer) detectors. In addition, gamma--gamma coincidence measurements and gamma multiscale measurements were made for both decays using Ge(Li) detectors. The half-life for 126 Cd was determined to be 0.506 +- 0.015 sec., and the half-lives for the low- and high-spin 126 In isomers were determined to be 1.83 +- 0.11 sec. and 1.96 +- 0.10 sec., respectively. A total of 11 gamma rays were observed in the decay of 126 Cd, and all but one were placed in a level scheme for 126 In. A total of 48 gamma rays were observed in the decay of the low- and high-spin 126 In isomers and all were placed in a level scheme for 126 Sn. Spin and parity assignments were deduced, whenever possible, on the basis of logft values and gamma decay selection rules. The 126 In decay schemes (one has been proposed for each isomer) are compared with earlier decay studies and with results from 124 Sn(t,p) 126 Sn reaction experiments. The systematics associated with the level schemes are discussed and a comparison is made with the nuclear shell model. 49 references

The Re-evaluation of {sup 84}Rb decay data

Energy Technology Data Exchange (ETDEWEB)

Xiaolong, Huang; Chunmei, Zhou [Chinese Nuclear Data Center, Beijing, BJ (China)

1996-06-01

The {sup 84}Rb is an important radionuclide and its decay data are fundamental data in nuclear applications. The decay data for {sup 84}Rb were re-evaluated. The energies and intensities of {gamma} rays and their internal conversion coefficients, energies and intensities of Auger electrons, conversion electrons and x-rays, were recommended. The decay scheme was also given. The balance of radiation rays intensities and energies was checked. (9 tabs., 2 figs.).

A control volume scheme for three-dimensional transport: buffer and matrix effect on a decay chain transport in the repository

International Nuclear Information System (INIS)

Lee, Y. M.; Hwang, Y. S.; Kim, S. G.; Kang, C. H.

2002-01-01

Using a three-dimensional numerical code, B3R developed for nuclide transport of an arbitrary length of decay chain in the buffer between the canister and adjacent rock in a high-level radioactive waste repository by adopting a finite difference method utilizing the control-volume scheme, some illustrative calculations have been done. A linear sorption isotherm, nuclide transport due to diffusion in the buffer and the rock matrix, and advection and dispersion along thin rigid parallel fractures existing in a saturated porous rock matrix as well as diffusion through the fracture wall into the matrix is assumed. In such kind of repository, buffer and rock matrix are known to be important physico-chemical barriers in nuclide retardation. To show effects of buffer and rock matrix on nuclide transport in HLW repository and also to demonstrate usefulness of B3R, several cases of breakthrough curves as well as three-dimensional plots of concentration isopleths associated with these two barriers are introduced for a typical case of decay chain of 234 U→ 230 Th→ 226 Ra, which is the most important chain as far as the human environment is concerned

Nuclear spectroscopy of neutron rich A = 147 nuclides: decay of 147Cs, 147Ba and 147La

International Nuclear Information System (INIS)

Shmid, M.; Chu, Y.Y.; Gowdy, G.M.

1981-01-01

A study of the beta decay of neutron rich nuclides of the A = 147 chain was carried out at the TRISTAN isotope separator. Half lives of 14 'Cs, 147 Ba and 147 La were measured. Six gamma lines are assigned to 147 Cs decay. A decay scheme for 147 Ba with levels up to 2 MeV is proposed for the first time. A partial decay scheme for 147 La is proposed, which confirms the previously existing one, with five new levels added from the present work

The decay of /sup 120/Xe

CERN Document Server

Münnich, F; Lode, D; Pessara, W; Schrader, H

1974-01-01

The decay scheme of 40 min /sup 120/Xe has been investigated using isotopically separated sources produced by the ISOLDE facility at CERN. A total number of 202 gamma -transitions has been observed in this decay; 188 of them have been placed in a level scheme involving 34 excited states in /sup 120/I. Most of these levels are based on the results of gamma - gamma coincidence experiments with two Ge(Li) detectors. Internal conversion coefficients have been obtained with a Si(Li) detector and a magnetic spectrometer. The half-life of 4 low- lying levels in /sup 120/I has been measured by delayed coincidence techniques. From these measurements, partial half-lives for some transitions have been deduced and are compared with the single- particle estimates. Two E2 transitions are strongly enhanced. (24 refs).

Electroweak penguin contributions to non-leptonic ΔF=1 decays at NNLO

International Nuclear Information System (INIS)

Buras, Andrzej J.; Gambino, Paolo; Haisch, Ulrich A.

2000-01-01

We calculate the O(α s ) corrections to the Z 0 -penguin and electroweak box diagrams relevant for non-leptonic ΔF=1 decays with F=S,B. This calculation provides the complete O(α W α s ) and O(α W α s sin 2 θ W m t 2 ) corrections (α W =α/sin 2 θ W ) to the Wilson coefficients of the electroweak penguin four quark operators relevant for non-leptonic K- and B-decays. We argue that this is the dominant part of the next-next-to-leading (NNLO) contributions to these coefficients. Our results allow us to reduce considerably the uncertainty due to the definition of the top quark mass present in the existing NLO calculations of non-leptonic decays. The NNLO corrections to the coefficient of the color singlet (V-A)x(V-A) electroweak penguin operator Q 9 relevant for B-decays are generally moderate, amount to a few percent for the choice m t (μ t =m t ) and depend only weakly on the renormalization scheme. Larger NNLO corrections with substantial scheme dependence are found for the coefficients of the remaining electroweak penguin operators Q 7 , Q 8 and Q 10 . In particular, the strong scheme dependence of the NNLO corrections to C 8 allows us to reduce considerably the scheme dependence of C 8 8 > 2 relevant for the ratio ε'/ε

Study of charmonium rare decays

International Nuclear Information System (INIS)

Brient, J.C.

1986-09-01

This thesis presents the study of rare decays of charmonium states formed in the interaction of an antiproton beam with an hydrogen gas jet target. Electromagnetic final states are used to sign the charmonium state formation (e + e - , e + e - + Χ, γγ). The selection of events used a two arms non magnetic spectrometer, with a charged track system, a threshold Cerenkov counter to tag the electron (positron), and an e.m. calorimeter. Energy scan technic have been used to observe the resonant formation through the excitation curves. Parameters of the states (mass, total and partial widths) are extracted from these curves using a statistical analysis. Two types of decays have been studied in this thesis: 1 P 1 charmonium state decay to the ψ (signed by its e + e - decay). In the energy scan around the center of gravity of the P charmonium states, we observe a cluster of 5 events, in a narrow mass range. This cluster correspond to a 2.7 σ signal. The most probable interpretation of this signal is given by a narrow resonance, with a mass of 3526. MeV. Due to the properties (mass, width and decay) of this signal, this could be interpreted as the 1 P 1 charmonium state. 2 photons decay of the η c and Χ 2 . 22 γγ events are observed, 15 in the η c region, and 7 in the Χ 2 region. This sample is interpreted as a direct observation of η c and Χ 2 decay into γγ. Parameters of these decays, (γγ partial width), are extracted using a maximum likekihood analysis. Theoretical models of charmonium explain correctly the properties of the charmonium, including the results presented in this thesis. 57 refs [fr

Systematic preservation of teeth and prophylaxis of dental decay on irradiated patients

International Nuclear Information System (INIS)

Horiot, J.C.; Schraub, S.

1975-01-01

200 patients were irradiated on the oral cavity and on salivary glands with doses of 3,000Rads and up. Teeth were preserved. A prophylactic treatment of dental decay was made using 5 minutes daily a fluoride gel into a carrier. The results showed an incidence of 5% for dental decay and 1% for osteo-radionecroses. Details are given about the selection of patients, the dental work-up and dental care before, during and after radiation therapy [fr

Heavy flavour decays at LEP

CERN Document Server

Rousseau, D H

2001-01-01

Recent heavy flavour results from LEP experiments are presented. Special emphasis is put on complex inclusive B reconstruction methods with high potentialities for lifetime, mixing, CP violation studies and new measurements of IVubl· The new world average of r8-f'r8o is 1.08 ± 0.03. The new world average of Re parameter measured in inclusive B0 decay is 0.001 ± 0.009. The new LEP average of JV ub I measured from inclusive b->ulv branching fraction is 4.

Detecting the (quasi-) two-body decays of /τ leptons in short-baseline neutrino oscillation experiments

Science.gov (United States)

Asratyan, A.; Balatz, M.; Boehnlein, D.; Childres, S.; Davidenko, G.; Dolgolenko, A.; Dzyubenko, G.; Kaftanov, V.; Kubantsev, M.; Reay, N. W.; Musser, J.; Rosenfeld, C.; Stanton, N. R.; Thun, R.; Tzanakos, G. S.; Verebryusov, V.; Vishnyakov, V.

1999-05-01

Novel detector schemes are proposed for the short-baseline neutrino experiments of next generation, aimed at exploring the large- Δm 2 domain of ν μ→ν τ oscillations in the appearance mode. These schemes emphasize good spectrometry for charged particles and for electromagnetic showers and efficient reconstruction of π0→ γγ decays. The basic elements are a sequence of relatively thin emulsion targets, immersed in magnetic field and interspersed with electronic trackers, and a fine-grained electromagnetic calorimeter built of lead glass. These elements act as an integral whole in reconstructing the electromagnetic showers. This conceptual scheme shows good performance in identifying the τ (quasi-) two-body decays by their characteristic kinematics and in selecting the electronic decays of the τ.

Detecting the (quasi-) two-body decays of τ leptons in short-baseline neutrino oscillation experiments

International Nuclear Information System (INIS)

Asratyan, A.; Balatz, M.; Boehnlein, D.; Childres, S.; Davidenko, G.; Dolgolenko, A.; Dzyubenko, G.; Kaftanov, V.; Kubantsev, M.; Reay, N.W.; Musser, J.; Rosenfeld, C.; Stanton, N.R.; Thun, R.; Tzanakos, G.S.; Verebryusov, V.; Vishnyakov, V.

1999-01-01

Novel detector schemes are proposed for the short-baseline neutrino experiments of next generation, aimed at exploring the large-Δm 2 domain of ν μ →ν τ oscillations in the appearance mode. These schemes emphasize good spectrometry for charged particles and for electromagnetic showers and efficient reconstruction of π 0 →γγ decays. The basic elements are a sequence of relatively thin emulsion targets, immersed in magnetic field and interspersed with electronic trackers, and a fine-grained electromagnetic calorimeter built of lead glass. These elements act as an integral whole in reconstructing the electromagnetic showers. This conceptual scheme shows good performance in identifying the τ (quasi-) two-body decays by their characteristic kinematics and in selecting the electronic decays of the τ

Scheme for quantum state manipulation in coupled cavities

Science.gov (United States)

Lin, Jin-Zhong

By controlling the parameters of the system, the effective interaction between different atoms is achieved in different cavities. Based on the interaction, scheme to generate three-atom Greenberger-Horne-Zeilinger (GHZ) is proposed in coupled cavities. Spontaneous emission of excited states and decay of cavity modes can be suppressed efficiently. In addition, the scheme is robust against the variation of hopping rate between cavities.

Weak decays and the dynamics of heavy quark production

International Nuclear Information System (INIS)

Milani, P.

1980-02-01

The parent-child relation governing the yield of particles arising from the subsequent decay of primarily-produced hadrons is investigated in the high-Psub(T) regime. An approximation scheme is developed and applied to the study of leptons and kaons coming from charged mesons produced in hadronic collisions. Correlations of the final particles are considered and a generalised Sternheimer relation, whereby given the moments of the decay distribution, the parent correlations may be simply extracted from the decay products, is developed. Finally the predictions of QCD for heavy quark production as observed through their weak decays, are investigated. (author)

Investigation of the 107Cd and 115Cd decay schemes and their application in neutron activation analysis

International Nuclear Information System (INIS)

Taha, M.

1980-01-01

The γ-decay of 107 Cd and 115 Cd was measured with a Ge(Li)-detector. In addition to improvements of the data of known transitions several transitions have been verified (sup(115m)Cd: 1074.18, 1596.18 keV, 107 Cd: 1142.47 keV). Some γ-lines were observed for the first time (sup(115m)Cd: 132.88, 1071.01, 1239.61 keV, 107 Cd: 132.62, 185.70, 474.56 keV). The results are interpreted by means of nuclear models. A k = 1/2-rotations band is verified by adding the 1071 and 1239 keV-states in the level scheme of 115 In. The multielement activation analysis was used for the detection of Cd traces in birch trees, which were taken from different environments. Evidence was found for the assumption that the Cd was taken up from the soil and enriched by the trees. (orig.)

Beta decay of /sup 39/Cl

International Nuclear Information System (INIS)

Wang, G.; Warburton, E.K.; Alburger, D.E.

1987-01-01

The β decay of /sup 39/Cl, produced in the /sup 37/Cl(t,p)/sup 39/Cl reaction at E/sub t/ = 3.1 MeV, has been investigated with a Ge-NaI(Tl) Compton-suppression γ-ray spectrometer. Nineteen γ-ray transitions were observed, including 10 previously known. Precision energy measurements were carried out on six of the strongest lines. In the proposed decay scheme a weak new β-ray branch is established to the 2950-keV level of /sup 39/Ar, and the populations of /sup 39/Ar levels at 2093 and 2433 keV are accounted for by γ-ray decays from higher excited states. Spin-parity assignments are given

Reinvestigation of 56Ni decay

International Nuclear Information System (INIS)

Sur, B.; Norman, E.B.; Lesko, K.T.; Browne, E.; Larimer, R.

1990-01-01

In a series of experiments, we have reinvestigated the decay of the doubly magic nucleus 56 Ni, which is believed to be copiously produced in supernovae. We have confirmed its previously known decay scheme and half-life, and have searched for several rare decay modes. We establish an upper limit of 5.8x10 -7 for the branching ratio of the second forbidden unique β + decay to the 158-keV level in 56 Co, leading to a lower limit of 2.9x10 4 yr for the half-life of fully ionized 56 Ni nuclei in cosmic rays. We also establish an upper limit of 5.0x10 -3 for the branching ratio of the isospin forbidden Fermi electron capture transition to the 1451-keV level in 56 Co, which in turn leads to an upper limit of 124 keV for the isospin mixing Coulomb matrix element of the 56 Ni ground state

Beta decay of 22O

International Nuclear Information System (INIS)

Hubert, F.; Dufour, J.P.; Moral, R. del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Delagrange, H.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

1989-01-01

The beta-gamma spectroscopic study of 22 O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n 40 Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from 22 O decay have been observed, from which a half-life of (2.25±0.15) s has been determined. Accurate excitation energies have been deduced for several states in 22 F. A partial beta decay scheme of 22 O has been established. Experimental results have been compared with shell model calculations. (orig.)

Two-body nonleptonic decays of charmed baryons

International Nuclear Information System (INIS)

Kohara, Y.

1998-01-01

Decay amplitudes of charmed baryons Λ c + , Ξ c 0 to an octet baryon and a pseudoscalar meson are calculated on the basis of the quark diagram scheme. restrictions imposed on the quark diagram amplitudes are also studied

Constraining neutrinoless double beta decay

International Nuclear Information System (INIS)

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

2012-01-01

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

Flavor-changing Z decays: A window to ultraheavy quarks

International Nuclear Information System (INIS)

Ganapathi, V.; Weiler, T.; Laermann, E.; Schmitt, I.; Zerwas, P.M.

1983-01-01

We study flavor-changing Z decays into quarks, Z→Q+q-bar, in the standard SU(2) x U(1) theory with sequential generations. Such decays occur in higher-order electroweak interactions, with a probability growing as the fourth power of the mass of the heaviest (virtual) quark mediating the transition. With the possible exception of Z→bs-bar, these decay modes are generally very rare in the three-generation scheme. However, with four generations Z→b'b-bar is observable if the t' mass is a few hundred GeV. Such decay modes could thus provide a glimpse of the ultraheavy-quark spectrum

Decay studies of Sr isotpes with high resolution and total absorption techniques

CERN Document Server

Perez-Cerdan, Ana-Belen

2012-04-03

High Resolution measurements The beta/EC decay of 77,78Sr and 76,78Rb have been studied in this work. Measurements were carried out of the energies and intensities of the emitted gamma-rays and conversion electrons as well as gamma-gamma and gamma-X-ray coincidences in the decays of 77,78Sr, which have extended our knowledge of their decay schemes including spin and parity assignments to the levels populated in the daughter nucleus, 77Rb and 78Rb respectively. For the decay of 78Sr, 16 new levels and 44 new gamma-ray transitions have been identified. The very much improved experimental knowledge of the 78Rb levels populated in the decay and the strong link between the parent and the daughter states has allowed us to infer some possible level configurations by comparison with HF+BCS calculations using the SG2 Skyrme force. For the decay of 77Sr, 9 new levels and 15 new gamma-ray transitions have been identified. The levels in the low energy part of the level scheme have been discussed in terms of HF+BCS+QRPA c...

KEWPIE: a dynamical cascade code for decaying exited compound nuclei

OpenAIRE

Bouriquet, Bertrand; Abe, Yasuhisa; Boilley, David

2003-01-01

A new dynamical cascade code for decaying hot nuclei is proposed and specially adapted to the synthesis of super-heavy nuclei. For such a case, the interesting channel is the tiny fraction that will decay through particles emission, thus the code avoids classical Monte-Carlo methods and proposes a new numerical scheme. The time dependence is explicitely taken into account in order to cope with the fact that fission decay rate might not be constant. The code allows to evaluate both statistical...

Analysis of subnanosecond fluorescence decay curves with a 5GHz real time detection system

International Nuclear Information System (INIS)

Cunin, B.; Heisel, F.; Knispel, G.; Miehe, J.A.; Sipp, B.

1975-01-01

This paper presents a detailed description and a review on the characteristics of a fast vacuum photoelectric cell associated with a high speed cathode ray tube. In addition, this system is used to measure short-lived fluorescence decay times [fr

Cosmological reconstruction of realistic modified F(R) gravities

International Nuclear Information System (INIS)

Nojiri, Shin'ichi; Odintsov, Sergei D.; Saez-Gomez, Diego

2009-01-01

The cosmological reconstruction scheme for modified F(R) gravity is developed in terms of e-folding (or, redshift). It is demonstrated how any FRW cosmology may emerge from specific F(R) theory. The specific examples of well-known cosmological evolution are reconstructed, including ΛCDM cosmology, deceleration with transition to phantom superacceleration era which may develop singularity or be transient. The application of this scheme to viable F(R) gravities unifying inflation with dark energy era is proposed. The additional reconstruction of such models leads to non-leading gravitational correction mainly relevant at the early/late universe and helping to pass the cosmological bounds (if necessary). It is also shown how cosmological reconstruction scheme may be generalized in the presence of scalar field.

Study of the influence of decay data in activation reaction cross section

International Nuclear Information System (INIS)

Huang Xiaolong; Lu Hanlin

2002-01-01

The effect of the decay data on the measured activation cross section is investigated carefully and testified by several examples. These decay data include the half-life of the product, γ branching ratio of the product and decay scheme. Present work shows that these effects must be considered carefully when evaluating the activation reaction cross section. Sometimes they are main reason for causing the discrepancies among the experimental data

Study on diverse passive decay heat removal approach and principle

International Nuclear Information System (INIS)

Lin Qian; Si Shengyi

2012-01-01

Decay heat removal in post-accident is one of the most important aspects concerned in the reactor safety analysis. Passive decay heat removal approach is used to enhance nuclear safety. In advanced reactors, decay heat is removed by multiple passive heat removal paths through core to ultimate heat sink by passive residual heat removal system, passive injection system, passive containment cooling system and so on. Various passive decay heat removal approaches are summarized in this paper, the common features and differences of their heat removal paths are analyzed, and the design principle of passive systems for decay heat removal is discussed. It is found that. these decay heat removal paths is combined by some basic heat transfer processes, by the combination of these basic processes, diverse passive decay heat removal approach or system design scheme can be drawn. (authors)

Beta-decay studies near 100Sn

International Nuclear Information System (INIS)

Rykaczewski, Krzysztof Piotr; Karny, M.; Batist, L.; Banu, A.; Becker, F.; Blazhev, A.; Burkard, K.; Bruchle, W.; Doring, J.; Faestermann, T.; Gorska, M.; Grawe, H.; Janas, Z.; Jungclaus, A.; Kavatsyuk, M.; Kavatsyuk, O.; Kirchner, R.; La Commara, M.; Mandal, S.; Mazzocchi, C.; Miernik, K.; Mukha, I.; Muralithar, S.; Plettner, C.; Plochocki, A.; Roeckl, E.; Romoli, M.; Schadel, M.; Schmidt, K.; Schwengner, R.; Zylicz, J.

2005-01-01

The β-decay of 102 Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the γ-γ coincidence data. The total experimental Gamow-Teller strength B GT exp of 102 Sn was deduced from the TAS data to be 4.2(9). A search for β-delayed γ-rays of 100 Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of 100 Sn in fusion-evaporation reaction between 58 Ni beam and 50 Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei

SU(3) properties of semileptonic and nonleptonic decays of mesons

International Nuclear Information System (INIS)

Montvay, I.

1977-11-01

The recent discovery of charmed D and F mesons led to an accumulation of a lot of information on the weak decays of these particles. The facts known at present are generally consistent with the Glashow-Iliopoulos-Maiami scheme for the weak currents, which are predicted the fourth flavour of quarks, the charm. The weak decays of the charmed mesons are governed by SU(3) rules analogous to the Okubo-Zweig-Iizuka rule for strong decays. Such Su(3) rules are given for semileptonic and nonleptonic decays of strange and charmed mesons. These relations depend on the colour structure of currents in the nonleptonic case. (D.P.)

In-beam alpha, electron, and gamma-ray spectroscopy of 215Fr

International Nuclear Information System (INIS)

Decman, D.J.; Grawe, H.; Kluge, H.; Maier, K.H.; Maj, A.; Menningen, M.; Roy, N.; Wiegner, W.

1983-01-01

The nucleus 215 Fr was studied using the 208 Pb( 11 B, 4n) and 204 Hg( 15 N, 4n) reactions. The measurements included α-γ, γ-γ, and e-e coincidence experiments as well as γ-ray and α-particle DPAD studies. The decay scheme gives levels up to a 3068 keV 39/2 - isomer with tsub(1/2)=(33 +- 5) ns as well as 3 shorter-lived isomers (tsub(1/2) approx.= 4 ns); g-factors have been measured for these isomers. The alpha-particle spectroscopy showed the existence of 4 longrange alphas which could be assigned to excited states in 215 Fr. tsub(1/2)( 215 Frsup(gs)) = (86+-5) ns has been remeasured. The negative parity states up to 1680 keV seem to be members of the π(h9/2) 5 9/2sup(ν)(g9/2) 2 configuration; a strong hindrance of M1 transitions is found. The higher lying states are compared with the DIPM model. (orig.)

Generalization of the event-based Carnevale-Hines integration scheme for integrate-and-fire models

NARCIS (Netherlands)

van Elburg, R.A.J.; van Ooyen, A.

2009-01-01

An event-based integration scheme for an integrate-and-fire neuron model with exponentially decaying excitatory synaptic currents and double exponential inhibitory synaptic currents has been introduced by Carnevale and Hines. However, the integration scheme imposes nonphysiological constraints on

Generalization of the Event-Based Carnevale-Hines Integration Scheme for Integrate-and-Fire Models

NARCIS (Netherlands)

van Elburg, Ronald A. J.; van Ooyen, Arjen

An event-based integration scheme for an integrate-and-fire neuron model with exponentially decaying excitatory synaptic currents and double exponential inhibitory synaptic currents has been introduced by Carnevale and Hines. However, the integration scheme imposes nonphysiological constraints on

Simulations of Bunch Merging in a Beta Beam Decay Ring

CERN Document Server

Heinrich, Daniel Christopher; Chance, Antoine

2011-01-01

To further study neutrino oscillation properties a Beta Beam facility has been proposed. Beta decaying ions with high kinetic energy are stored in a storage ring ("Decay Ring") with straight sections to create pure focused (anti) electron neutrino beams. However to reach high sensitivity to neutrino oscillation parameters in the experiment the bunched beam intensity and duty cycle in the DR have to be optimized. The first CERN-based scenario, using 6He and 18Ne as neutrino sources, has been studied using a bunch merging RF scheme. Two RF cavities at different frequencies are used to capture newly injected bunches and then merge them into the stored bunches. It was shown that this scheme could satisfy the requirements on intensity and duty cycle set by the experiment. This merging scheme has now been revised with new simulation software providing new results for 6He and 18Ne. Furthermore bunch merging has been studied for the second CERN-based scenario using 8Li and 8B.

Levels in 223Th populated by α decay of 227U

Science.gov (United States)

Kalaninová, Z.; Antalic, S.; Heßberger, F. P.; Ackermann, D.; Andel, B.; Kindler, B.; Laatiaoui, M.; Lommel, B.; Maurer, J.

2015-07-01

Levels in 223Th populated by the α decay of 227U were investigated using α -γ decay spectroscopy. The 227U isotope was produced in the fusion-evaporation reaction 22Ne +208Pb at the velocity filter separator for heavy-ion reaction products at Gesellschaft für Schwerionenforschung in Darmstadt (Germany). Several new excited levels and γ transitions were identified in 223Th . An improved α -decay scheme of 227U was suggested. The experimental α -decay energy spectrum of 227U was compared with the Monte Carlo simulation performed using the toolkit geant4.

KEWPIE: A dynamical cascade code for decaying exited compound nuclei

Science.gov (United States)

Bouriquet, Bertrand; Abe, Yasuhisa; Boilley, David

2004-05-01

A new dynamical cascade code for decaying hot nuclei is proposed and specially adapted to the synthesis of super-heavy nuclei. For such a case, the interesting channel is of the tiny fraction that will decay through particles emission, thus the code avoids classical Monte-Carlo methods and proposes a new numerical scheme. The time dependence is explicitely taken into account in order to cope with the fact that fission decay rate might not be constant. The code allows to evaluate both statistical and dynamical observables. Results are successfully compared to experimental data.

The analysis of predictability of recent alpha decay formulae and the alpha partial half-lives of some exotic nuclei

International Nuclear Information System (INIS)

Dasgupta-Schubert, N.; Reyes, M. A.; Tamez, V. A.

2009-01-01

Alpha decay is one of the two main decay modes of the heaviest nuclei, (SHE), and constitutes one of the dominant decay modes of highly neutron deficient medium mass nuclei ('exotics'). Thus identifying and characterizing the alpha decay chains form a crucial part of the identification of SHE. We report the extension of the previously developed method for the detailed and systematic investigation of the reliability of the three main extant analytical formulae of alpha decay half-lives: the generalized liquid drop model based formula of Royer et al. (FR), the Sobiczewski modified semi-empirical Viola-Seaborg formula (VSS) and the recent phenomenological formula of Sobiczewski and Parkhomenko (SP).

Readout and triggering of the Soudan 2 nucleon decay experiment

International Nuclear Information System (INIS)

Thron, J.L.

1984-01-01

The readout and triggering electronics for the Soudan 2 proton decay detector is presented. Pratically all the electronics is implemented in CMOS. The triggering scheme is highly flexible and software controllable

$\\alpha$-decay study of $^{182,184}$Tl

CERN Document Server

Van Beveren, C; Barzakh, A E; Cocolios, T E; de Groote, R P; Fedorov, D; Fedosseev, V N; Ferrer, R; Ghys, L; Huyse, M; Köster, U; Lane, J; Liberati, V; Lynch, K M; Marsh, B A; Molkanov, P L; Procter, T J; Rapisarda, E; Sandhu, K; Seliverstov, M D; Van Duppen, P; Venhart, M; Veselský, M

2016-01-01

α -decay spectroscopy of 182,184 Tl has been performed at the CERN isotope separator on-line ( ISOLDE ) facility. New fi ne-structure α decays have been observed for both isotopes. α -decay branching ratios of 0.089 ( 19 ) %, 0.047 ( 6 ) % and 1.22 ( 30 ) % have been deduced for the ( 10 − ) , ( 7 + ) and ( 2 − ) states respectively in 184 Tl and a lower limit of 0.49% for the α -decay branching ratio of 182 Tl. A new half-life of 9.5 ( 2 ) s for the ( 2 − ) state in 184 Tl and 1.9 ( 1 ) s for the low-spin state in 182 Tl has been deduced. Using α – γ coincidence analysis, multiple γ rays were observed de-exciting levels in 178,18 0 Au fed by 182,184 Tl α decays. The γ transitions connecting these low-lying states in 178,18 0 Au are essential to sort the data and possibly identify bands from in- beam studies in these isotopes. Owing to the complex fi ne-structure α decays and limited knowledge about the structure of the daughter nuclei, only partial level schemes could be constructed for bot...

Quasi two-body decays of D0 meson

International Nuclear Information System (INIS)

Terasaki, K.; Oneda, S.

1985-08-01

Quasi two-body decays of D 0 -meson are studied from an algebraic approach, using a hard meson extrapolation. In this innovation of old current algebra with new perspective, a reasonable unified description of K sub(S) → 2π and D 0 → K-barπ decays has been obtained previously, keeping only the contribution of ground state mesons to the now surviving surface term. In this paper, it is shown that quasi two-body decays can also be accomodated reasonably well in the same scheme. A distinctive feature of our result is that GAMMA(D 0 → phi K-bar 0 ) is sizable, while D 0 → rho 0 K-bar 0 is relatively suppressed. (author)

Nuclear structure from radioactive decay: Annual progress report

International Nuclear Information System (INIS)

Wood, J.L.

1988-01-01

The primary focus this year has been the continuing studies of intruder states and shape coexistence in the neutron-deficient Z /approximately/ 82 region. Most notably, an extensive region of odd-mass nuclei is emerging within which low-lying low-energy electric monopole (EO) transitions occur. This is a completely new nuclear structure phenomenon. The empirical results are based on on-line decay scheme spectroscopy of mass-separated isotopes at UNISOR. In particular, many transition multipolarities are determined from conversion electron subshell ratios observed in γ-gated electron coincidence spectra. This is a completely new nuclear spectroscopic technique. To cite a specific example: our studies of the 185 Au → 185 Pt decay scheme reveal at least 11 transitions with EO components. This is unprecedented in nuclear structure. The role of EO transitions is being pursued in the larger framework of a signature of shape coexistence in nuclei

Computer simulation of the natural U 238 and U 235 radioactive series decay

International Nuclear Information System (INIS)

Barna, A.; Oncescu, M.

1980-01-01

The principles of the computer simulation of a radionuclide decay - its decay scheme adoption and codification -, and the adoption principle of a radionuclide chain in a series are applied to the natural U 238 and U 235 series radionuclide decay computer simulation. Using the computer simulation data of these two series adopted chains, the decay characteristic quantities of the series radionuclides, the gamma spectra and the basic characteristics of each of these series are determined and compared with the experimental values given in the literature. (author)

Nuclear structure effects in the exotic decay of $^{225}$Ac via $^{14}$C emission

CERN Document Server

Bonetti, R; Guglielmetti, A; Matheoud, R; Migliorino, C; Pasinetti, A L; Ravn, H L

1993-01-01

By using a $^{225}$Ac source produced at the electromagnetic separator Isolde we collected on our track-recording glass detectors 305 $^{14}$C events from the radioactive decays of $^{225}$Ac and its daughter $^{221}$Fr and obtained, for $^{225}$Ac, a branching ratio B($^{14}$C/$\\alpha$)=(6.0 $\\pm$ 1.3) x 10$^{-12}$. Our result suggests that such a decay from an odd proton nucleus is dominated by transition to the ground or to the first excited state of daughter nucleus.

Applications of Rajeval technique for the evaluation of discrepant nuclear decay data

International Nuclear Information System (INIS)

Rajput, M.U.

2006-11-01

There are 4 levels 95NB below the decay energy in the Adopted Levels of the 93 micro 08 evaluation that are not reported in this decay scheme: these are 730 6 (5/2+), 799 5 (3/2), 1011 8 (5/2), and 1088keV. These levels have only been reported in reaction studies and their lemma decay modes are not known the 730 level would be fed fed by and allowed beta decay, so this evaluator suggests it is actually the 724 level and the J* assignment is incorrect. The failure to observe decays to the possible 799 and 1011 levels is surprising since these would be 1st forbidden decays and from beta decay systematics (73Ra10) could have branches of several percent. Therefore, one must rely on the fact that other lemda rays have not been reported to support the completeness of this scheme. If one leaves the values of 65F102 in the data set, it is desirable to use either the RAJEVAL or Normalized Residual method to treat this discrepancy. The RAJEVAL method increase the uncertainty for the 65F102 value from 0.2 to 0.88 and gives the resulting value of 64.032(6) while the Normalized Residual method increase this uncertainty to 0.58 and give a result of 64.032(6). So, the adopted value is the same for each of these three methods. (author)

Gluon fragmentation in T(1S) decays

International Nuclear Information System (INIS)

Bienlein, J.K.

1983-05-01

In T(1S) decays most observables (sphericity, charged multiplicity, photonic energy fraction, inclusive spectra) can be understood assuming that gluons fragment like quarks. New results from LENA use the (axis-independent) Fox-Wolfram moments for the photonic energy deposition. Continuum reactions show 'standard' Field-Feynman fragmentation. T(1S) decays show a significant difference in the photonic energy topology. It is more isotropic than with the Field-Feynman fragmentation scheme. Gluon fragmentation into isoscalar mesons (a la Peterson and Walsh) is excluded. But if one forces the leading particle to be isoscalar, one gets good agreement with the data. (orig.)

Nuclear spectroscopic investigations of the decay of /sup 155/Eu

Energy Technology Data Exchange (ETDEWEB)

Patt, B H

1974-01-01

The investigations carried out on the ..beta..-decay of /sup 155/Eu confirm some decay data of this nucleus and explain a few disagreements on the decay scheme. Using the half-life, the ..beta..-boundary energies and branching ratios, the log ft values of the individual ..beta..-transitions were calculated. Finally, by means of ..beta gamma..-coincidence measurements on the semiconductor spectrometer, the inner partial spectra ..beta../sub 3/ and ..beta../sub 4/ were separated for the first time. Form factor investigations were carried out on these spectra which, despite the high log ft values, confirm the allowed character of these transitions.

Decay of new mass-separated neutron-deficient La and Ce isotopes

International Nuclear Information System (INIS)

Genevey, J.; Gizon, A.; Idrissi, N.; Weiss, B.; Beraud, R.; Charvet, A.; Duffait, R.; Emsallem, A.; Meyer, M.; Ollivier, T.; Redon, N.

1987-01-01

By use of a He jet system coupled to a Bernas-Nier ion-source, several new mass-separated A = 122 - 127 isotopes reached in heavy ion fusion reactions at SARA have been identified and studied. From experimental decay properties of La isotopes, systematics of low-lying energy levels have been extended for even-even and odd-A barium. New informations on Ce decay schemes are briefly reported

The states of 73Se populated by the beta decay of 73Br

International Nuclear Information System (INIS)

Heiguchi, K.; Mitarai, S.; Min, B.J.; Kuroyanagi, T.

1987-01-01

Decay of mass-separated samples of the nuclide 73 Br have been investigated by means of an on-line isotope separator in the Tandem Accelerator Laboratory of Kyushu University. Twenty eight γ-rays were assigned to the decay of 73 Br. The half-life was measured to be 3.4±0.2 min. The decay scheme of 73 Br was constructed on the basis of γ-ray energies, intensities of γ-rays and conversion electrons, and relations of γγ-, βγ- and γ(ce)-coincidences. Spins and parities of the ten levels of 73 Se were assigned or limited according to log ft values, conversion coefficients and branching ratios of the transitions. Systematical trends in the level schemes of N=39 isotones 69 Zn, 71 Ge, 73 Se, 75 Kr and 77 Sr are discussed. (orig.)

Selected spectroscopic results on element 115 decay chains

International Nuclear Information System (INIS)

Rudolph, D.; Forsberg, U.; Golubev, P.; Sarmiento, L.G.; Yakushev, A.; Andersson, L.L.; Di Nitto, A.; Duellmann, Ch.E.; Gates, J.M.; Gregorich, K.E.

2015-01-01

Thirty correlated α-decay chains were observed in an experiment studying the fusion-evaporation reaction 48 Ca + 243 Am at the GSI Helmholtzzentrum fuer Schwerionenforschung. The decay characteristics of the majority of these 30 chains are consistent with previous observations and interpretations of such chains to originate from isotopes of element Z = 115. High-resolution α-photon coincidence spectroscopy in conjunction with comprehensive Monte-Carlo simulations allow to propose excitation schemes of atomic nuclei of the heaviest elements, thereby probing nuclear structure models near the 'Island of Stability' with unprecedented experimental precision. (author)

β decays on the rotational levels of the 5/2+[642] 169Yb band

International Nuclear Information System (INIS)

Dzhelepov, B.S.; Zhukovskij, N.N.; Shestopalova, S.A.

1993-01-01

Competing 169 Lu β decays into rotational levels of 5/2 + [642] 169 Yb band are considered. Schemes of resolved β decay into 3 levels of deformed nucleus rotational bands, γ transitions linked with excitation and discharge of 169 Yb 5/2, 7/2, 9/2, 5/2 + [642] levels are presented. Matrix elements of axial-vector decay are determined. Data on 12 γ transitions in 169 Lu are presented

Charm-conserving strangeness-changing two body hadronic decays of charmed baryons

International Nuclear Information System (INIS)

Khanna, M.P.

1993-10-01

The charm-conserving strangeness-changing two body hadronic decays of charmed baryons are examined in the SU(4) symmetry scheme. In addition to the 20''-Hamiltonian, we consider a 15-piece of the weak Hamiltonian which may arise due to SU(4) breaking or due to some non-conventional dynamics. The numerical estimates for decay widths of some of the modes are presented. (author). 15 refs, 3 tabs

Quark-mixing renormalization effects on the W-boson partial decay widths

International Nuclear Information System (INIS)

Almasy, A.A.; Kniehl, B.A.; Sirlin, A.

2008-10-01

We briefly review existing proposals for the renormalization of the Cabibbo- Kobayashi-Maskawa matrix and study their numerical effects on the W-boson partial decay widths. The differences between the decay widths predicted by the various renormalization schemes are generally negligible, while their deviations from the MS results are very small, except for W + → u anti b and W + →c anti b, where they reach approximately 4%. (orig.)

The Nucleus 59Cu. Complex Structure, Shape Evolution, Exotic Decay Modes

International Nuclear Information System (INIS)

Andreoiu, Corina

2002-08-01

High-spin states in the mass A∼60 region were populated using the state-of-art γ-ray spectrometers Gammasphere, Euroball, and GASP in conjunction with dedicated ancillary detectors. In particular, the 59 Cu nucleus was studied in several experiments, and a very extensive level scheme was determined. It comprises more than 320 transitions connecting about 150 excited states. Relative to mass, it is the most extensive level scheme known to date. Next to the spherical states at low excitation energy eight regular sequences of high-energy γ-ray transitions have been observed. They form rotational bands with various degree of deformation, which are interpreted in the light of the shell model and the configuration-dependent Cranked Nilsson-Strutinsky approach. One of the experiments was dedicated to the study of prompt particle decays. It revealed five prompt proton decays connecting five deformed states in three of the rotational bands in 59 Cu with three spherical states in the daughter nucleus 58 Ni. It is the first observation of the fine structure of the newly discovered prompt proton decay mode. The proton decays compete with the γ decay-out from the second minimum of the nuclear potential into the low-spin spherical states in the first minimum of the potential. The discrete γ decay-out mechanism of the yrast superdeformed band is investigated in detail. The nucleus 59 Zn, the mirror partner of 59 Cu, was identified for the first time, and the mirror symmetry of the T=1/2 A=59 pair is discussed

An attempt for revision of JNDC FP decay data file

International Nuclear Information System (INIS)

Katakura, Jun-ichi; Matsumoto, Zyun-itiro; Akiyama, Masatsugu; Yoshida, Tadashi; Nakasima, Ryozo.

1984-06-01

Some improvement of JNDC FP Decay Data File is tried by reexamining the decay scheme for several nuclides, since slight discrepancies are seen in detailed comparison of decay powers. As a results, it is found that the average beta- and gamma-energies should be modified for 88 Rb and 143 La among the nuclides reexamined in the present study. The JNDC file modified in 88 Rb and 143 La gives better agreement in most cases with experiments than the original JNDC file for cooling times longer than a few thousands seconds. However, the discrepancy for cooling times from a few hundreds to about 1500 seconds still remains. (author)

Nuclear Structure Effects in the Exotic Decay of $^{225}$Ac via $^{14}$C Emission

CERN Multimedia

2002-01-01

% IS323 \\\\ \\\\ We propose to build at Isolde a high intensity $^{225}$Ac source by $\\beta$-decay of $^{225}$(Ra+Fr) beam, to be used at the superconducting spectrometer SOLENO of IPN-Orsay in order to study a possible fine structure in the spectrum of $^{14}$C ions spontaneously emitted by $^{225}$Ac.

Zweig rule violation decays of the new particles

International Nuclear Information System (INIS)

Chaichian, M.; Hayashi, M.

1976-01-01

The specific decay modes of the new psi particles and their cascade products are considered according to an approximate scheme of sequential pole dominance proposed by Freund and Nambu, which is dictated by the dual model dynamics. Predictions and comparison with available data are presented. While asymptotically free gauge theory can trace the origin of violation of Zweig rule and the smallness of psi width, it can only give an estimate of the over-all violation of the rule and is not well suited for each decay channel separately. The sequential pole model fulfils this task. (Auth.)

Decay of mass-separated 189mHg (8.7 min) and 189gHg (7.7 min) to 189Au

International Nuclear Information System (INIS)

Wood, J.L.; Zganjar, E.F.; Semmes, P.B.

1996-01-01

The decays of 189 Hg (8.7 min; J π =13/2 + ) and 189 Hg (7.7 min; J π =3/2 - ) have been studied with mass-separated sources from the UNISOR facility. Multiscaled spectra of γ-rays, X-rays, and conversion electrons, as well as γγt, γXt, eγt, and eXt coincidences were obtained. Decay schemes have been constructed incorporating >95% of the decay intensities assigned to the high-spin and low-spin decays. The γ-ray gated conversion-electron spectra permitted the determination of 119 conversion-electron subshell ratios. Portions of the level scheme bear a remarkable resemblance to the heavier and lighter odd-mass Au isotopes. An extensive band of states is observed built upon the h 9/2 intruder state at 325 keV. This band is markedly different from the corresponding bands in 187 Au and 185 Au, indicating a major change in the cores, i.e. between 188 Pt and 186,184 Pt. Evidence for oblate-hole-prolate-particle symmetry in 189 Au is discussed. Completeness of complex decay schemes far from stability is addressed. (orig.)

Simple theory of nonleptonic kaon decays

International Nuclear Information System (INIS)

Scadron, M.D.; Choudhury, S.R.

1987-07-01

We first summarize (a) why the quark s-bar-d-bar loop transition dominated by the physical W + exchange controls the large ΔI=1/2 K π and K 2π o nonleptonic decay amplitudes, and (b) why the vacuum-saturated hadronic (implied W + ) current-current hamiltonian correctly explains the small ΔI-3/2 K 2π + decay. Then we study in greater detail a more complete hadronic D.K.π meson-W ± loop calculation of the ΔI=1/2 and ΔI=3/2 K 2π amplitudes and show that this picture further reinforces our original quark ΔI=1/2 and hadron vacuum-saturated ΔI=3/2 (long distance) scheme. (author). 29 refs, 8 figs

A=225 implantation for $^{221}$Fr source for TRIUMF atom trap

CERN Multimedia

The FrPNC Collaboration is mounting an atom trap for parity violation experiments and precision spectroscopy on francium atoms at TRIUMF's ISAC facility. We would like to use ISOLDE's capability of simultaneously implanting A=225 (while another experiment runs online) to make a long-lived source feeding $^{221}$Fr for tests of the trap. $^{225}$Ra $\\beta$-decays to $^{225}$Ac, which then $\\alpha$-decays, producing 100 keV $^{221}$Fr t$_{1/2}$= 4.8 minute recoils. The implanted A=225 source would be shipped to TRIUMF, where it would be held for several minutes at a time a few mm from the same yttrium foil that normally receives the ISAC beam. SRIM calculations imply that 20% of the $^{221}$Fr will be implanted in a 1 cm diameter spot on the yttrium. Then the yttrium foil is moved to the trap and heated to release the Fr atoms, just as in normal ISAC online operation. A test implantation will be done at 10$^{7}$/sec production for 1 day, testing whether carbon cracking on the implantation foil in the mass separ...

Droplet condensation in rapidly decaying pressure fields

International Nuclear Information System (INIS)

Peterson, P.F.; Bai, R.Y.; Schrock, V.E.; Hijikata, K.

1992-01-01

Certain promising schemes for cooling inertial confinement fusion reactors call for highly transient condensation in a rapidly decaying pressure field. After an initial period of condensation on a subcooled droplet, undesirable evaporation begins to occur. Recirculation within the droplet strongly impacts the character of this condensation-evaporation cycle, particularly when the recirculation time constant is of the order of the pressure decay time constant. Recirculation can augment the heat transfer, delay the onset of evaporation, and increase the maximum superheat inside the drop by as much as an order of magnitude. This numerical investigation identifies the most important parameters and physics characterizing transient, high heat flux droplet condensation. The results can be applied to conceptual designs of inertial confinement fusion reactors, where initial temperature differences on the order of 1,500 K decay to zero over time spans the order of tens of milliseconds

Absolute branching intensities in the decay of 92Rb to 92Sr

CERN Document Server

Lhersonneau, G; Rizzi, V; Alyakrinskiy, O; Lanchais, A; Volkov, Yu.M; Barzakh, A.E; Fedorov, D.V; Ionan, A.M; Ivanov, V.S; Mezilev, K.A; Moroz, F.V; Orlov, S.Yu; Panteleev, V.N; Lau, C; Bajeat, O; Essabaa, S; Leroy, R; Jardin, P; Stroe, L; 10.1103/PhysRevC.74.017308

2006-01-01

The branching of the 2+ to 0+ transition in 92Sr has been measured to 0.032(4) per 92Rb decay. It confirms an earlier measurement however discarded in nuclear data evaluations since in contradiction with accepted lower logft limits. The conflict could be solved assuming that close to half of the decay intensity, mostly as high-energy ground-state transitions, is missing in th edecay scheme.

Flavor-changing Z0 decay

International Nuclear Information System (INIS)

Axelrod, A.

1982-10-01

Chapter I reviews the phenomenological situation. Simple estimates of various rates are also provided in order to convey the physical intuition necessary to guide one through the equations and numbers that follow. Chapter II presents technical aspects of the general flavor changing Z 0 decay calculation, with emphasis on the integration scheme used. Chapter III describes a number of nontrivial checks on the calculation that were performed. Chapter IV contains the entire general algebraic result for the decay rate. Chapter V describes numerical aspects of the computer evaluation, and discusses the parameter values used and the results for the three generation case. A similar presentation for the four generation case is given in Chapter VI. Chapter VII describes what experimentalists should look for in a semiquantitative way. Some possibilities for rate enhancement, and some related processes are mentioned in Chapter VIII

Beta decay of 22O

International Nuclear Information System (INIS)

Hubert, F.; Dufour, J.P.; Del Moral, R.; Fleury, A.; Jean, D.; Pravikoff, M.S.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

1989-01-01

The study of light nuclei far from stability has been recently renewed by the possibility of production through the projectile fragmentation of intermediate energy heavy ion beams at GANIL. The results presented here have been obtained with the Projectile Fragments Isotopic Separation method developed at the LISE spectrometer. 22 O is a Tz = 3 nucleus and is the first in a series of seven such nuclei in the sd shell extending from 22 O to 24 Mg. Although the half life of 22 O was previously measured by Murphy et al., the present study is the first beta-gamma spectroscopy on this neutron rich nucleus. Five gamma lines have been attributed to the β decay of 22 O with a measured half life of T = (2.25±0.15)s and a partial decay scheme has been established

The Emergent Universe scheme and tunneling

Energy Technology Data Exchange (ETDEWEB)

Labraña, Pedro [Departamento de Física, Universidad del Bío-Bío, Avenida Collao 1202, Casilla 5-C, Concepción, Chile and Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos, Universitat (Spain)

2014-07-23

We present an alternative scheme for an Emergent Universe scenario, developed previously in Phys. Rev. D 86, 083524 (2012), where the universe is initially in a static state supported by a scalar field located in a false vacuum. The universe begins to evolve when, by quantum tunneling, the scalar field decays into a state of true vacuum. The Emergent Universe models are interesting since they provide specific examples of non-singular inflationary universes.

Radiative corrections in K→3π decays

International Nuclear Information System (INIS)

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

2009-01-01

We investigate radiative corrections to K→3π 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 α may be applied. We expect that the formulae provided allow one to extract S-wave ππ scattering lengths from the cusp effect in these decays with high precision

Bose-Einstein correlations in W-pair decays

CERN Document Server

Barate, R; Ghez, P; Goy, C; Jézéquel, S; Lees, J P; Martin, F; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Morawitz, P; Pacheco, A; Riu, I; Ruiz, H; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Boix, G; Buchmüller, O L; Cattaneo, M; Cerutti, F; Ciulli, V; Davies, G; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Gianotti, F; Greening, T C; Halley, A W; Hansen, J B; Harvey, J; Janot, P; Jost, B; Kado, M; Leroy, O; Maley, P; Mato, P; Minten, Adolf G; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tournefier, E; Valassi, Andrea; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Blondel, A; Brient, J C; Machefert, F P; Rougé, A; Swynghedauw, M; Tanaka, R; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Chalmers, M; Kennedy, J; Lynch, J G; Negus, P; O'Shea, V; Räven, B; Smith, D; Teixeira-Dias, P; Thompson, A S; Ward, J J; Cavanaugh, R J; Dhamotharan, S; Geweniger, C; Hanke, P; Hepp, V; Kluge, E E; Leibenguth, G; Putzer, A; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Marinelli, N; Martin, E B; Nash, J; Nowell, J; Przysiezniak, H; Sciabà, A; Sedgbeer, J K; Thompson, J C; Thomson, E; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Robertson, N A; Smizanska, M; Williams, M I; Giehl, I; Hölldorfer, F; Jakobs, K; Kleinknecht, K; Kröcker, M; Müller, A S; Nürnberger, H A; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H W; Zeitnitz, C; Ziegler, T; Aubert, Jean-Jacques; Bonissent, A; Carr, J; Coyle, P; Ealet, A; Fouchez, D; Tilquin, A; Aleppo, M; Antonelli, M; Gilardoni, S S; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Lefrançois, J; Serin, L; Veillet, J J; Videau, I; De Vivie de Régie, J B; Zerwas, D; Bagliesi, G; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Ferrante, I; Giassi, A; Gregorio, A; Ligabue, F; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Coles, J; Cowan, G D; Green, M G; Hutchcroft, D E; Jones, L T; Medcalf, T; Strong, J A; Botterill, David R; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Bloch-Devaux, B; Colas, P; Fabbro, B; Faïf, G; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Rosowsky, A; Seager, P; Trabelsi, A; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Loomis, C; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Hodgson, P N; Lehto, M H; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Grupen, Claus; Hess, J; Misiejuk, A; Prange, G; Sieler, U; Borean, C; Giannini, G; Gobbo, B; Pütz, J; Rothberg, J E; Wasserbaech, S R; Williams, R W; Armstrong, S R; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Von Wimmersperg-Töller, J H; Wu Sau Lan; Wu, X; Zobernig, G

2000-01-01

Bose-Einstein correlations are studied in semileptonicWW --> qqbarlnu and fully hadronic WW --> qqbarqqbar W-pair decays with the ALEPH detector at LEP at centre-of-mass energies of 172, 183 and 189GeV. They are compared with those made at the Z peak after correction for the different flavour compositions. A Monte Carlo model of Bose-Einsteincorrelations based on the JETSET hadronization scheme was tuned to the Z data and reproduces the correlations in the WW --> qqbarlnu events. The same Monte Carlo reproduces the correlations in the WW --> qqbarqqbarchannel assuming independent fragmentation of the two W's. A variant thismodel with Bose-Einstein correlations between decay products of different W's is disfavoured.

Search for R-Parity Violating Decays of Scalar Fermions at LEP

CERN Document Server

Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lawson, I.; Layter, J.G.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; 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, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

2000-01-01

A search for pair produced scalar fermions with couplings that violate R-parity has been performed using a data sample corresponding to an integrated luminosity of 56 pb-1 at a centre-of-mass energy of sqrt{s}= 183 GeV collected with the OPAL detector at LEP. An important consequence of R-parity breaking interactions is that the lightest supersymmetric particle is expected to be unstable. Searches for R-parity violating decays of charged sleptons, sneutrinos and stop quarks have been performed under the assumptions that the lightest supersymmetric particle decays promptly and that only one of the R-parity violating couplings is dominant for each of the decay modes considered. Such processes would yield multi-leptons, jets plus leptons or multi-jets, with or without missing energy, in the final state. No significant excess of such events has been observed. Limits on the production cross-sections of scalar fermions in R-parity violating scenarios are obtained. Mass exclusion regions are also presented in the fr...

Charm photoproduction. Decays and time of life of the strange-charm meson

International Nuclear Information System (INIS)

Magneville, C.

1988-07-01

In this thesis, decays and lifetimes of the charmed D +- and F mesons have been studied, using the datas of the NA14-2 experiment at CERN. We have filtered events with two kaons of opposite signs. We have used a silicon vertex detector, which consists of an active target and microstrips planes, in order to reconstruct and separate the interaction vertex from the decay vertex. Cuts on distance of flight have been made. This has allowed a good rejection of combinatorial background and the extraction of clean D +- , F (in KKπ) and Λ c (in pKπ) signals. We measure their times of flight and compare to the theoretical predictions [fr

Higgs-boson production and decay close to thresholds

International Nuclear Information System (INIS)

Kniehl, B.A.; Palisoc, C.P.; Sirlin, A.; New York Univ., NY

2000-07-01

At one loop in the conventional on-mass-shell renormalization scheme, the production and decay rates of the Higgs boson H exhibit singularities proportional to (2M V -M) -1/2 as the Higgs-boson mass M approaches from below the pair-production threshold of a vector boson V with mass M V . This problem is of phenomenological interest because the values 2M W and 2M Z , corresponding to the W- and Z-boson thresholds, lie within the M range presently favoured by electroweak precision data. We demonstrate how these threshold singularities are eliminated when the definitions of mass and total decay width of the Higgs boson are based on the complex-valued pole of its propagator. We illustrate the phenomenological implications of this modification for the partial width of the H → W + W - decay. (orig.)

Higgs-boson production and decay close to thresholds

International Nuclear Information System (INIS)

Kniehl, Bernd A.; Palisoc, Caesar P.; Sirlin, Alberto

2000-01-01

At one loop in the conventional on-mass-shell renormalization scheme, the production and decay rates of the Higgs-boson H exhibit singularities proportional to (2M V -M) -1/2 as the Higgs-boson mass M approaches from below the pair-production threshold of a vector boson V with mass M V . This problem is of phenomenological interest because the values 2M W and 2M Z , corresponding to the W- and Z-boson thresholds, lie within the M range presently favoured by electroweak precision data. We demonstrate how these threshold singularities are eliminated when the definitions of mass and total decay width of the Higgs-boson are based on the complex-valued pole of its propagator. We illustrate the phenomenological implications of this modification for the partial width of the H→W + W - decay

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.

Decay of 185Au: sign of shape coexistence in 185Pt

International Nuclear Information System (INIS)

Roussiere, B.; Bourgeois, C.; Kilcher, P.; Sauvage, J.; Porquet, M.G.

1984-01-01

The decay of 185 Au has been studied on-line with mass-separated sources from the ISOCELE facility. Precise conversion-electron measurements have been performed with a 180 0 magnetic spectrograph. Level scheme of 185 Pt has been established, and the Tsub(1/2)=33 min isomeric state has been located at 103.2 keV with respect to the Tsub(1/2)=71 min ground state. Two very converted transitions have been observed. The level scheme is discussed in the framework of an ''axial-rotor + quasi-particle'' approach: numerous states are interpreted assuming a prolate shape of the nucleus. Ten levels with low-spin and negative-parity (π - ) decay mainly to the 1/2 - [521] band via strong M1 transitions and are not expected from the calculations performed with the prolate cores. The possibility of shape coexistence is discussed

LHCb: Search for CP violation in $D^+ \\to K^-K^+\\pi^+$ decays at LHCb

CERN Multimedia

Gordon, Hamish

2012-01-01

A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \\to K^-K^+\\pi^+$ in a sample of approximately 370,000 decays is described. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.

The β+-electron capture decay of 73Kr

International Nuclear Information System (INIS)

Miehe, C.; Dessagne, P.; Pujol, Ch.; Walter, G.; Jonson, B.; Lindroos, M.

1999-01-01

The β + - electron capture decay of 73 Kr, produced at the ISOLDE CERN facility, has been studied by β-delayed proton and gamma emission. The established decay scheme involves 15 up to now unreported gamma emitting levels in 73 Br. The total proton branching ratio has been measured to be 0.0025±0.0003. From this work, a spin and parity 3/2 - is assigned to the 73 Kr ground state, on the basis of the allowed β branch to the 73 Br J π =1/2 - ground state and the feeding of the 5/2 + level located at 286 keV in 73 Br. (orig.)

Study of 193Os beta- decay

International Nuclear Information System (INIS)

Zahn, Guilherme Soares

2006-01-01

In this work, the excited levels of 193 Ir populated by the beta - decay of 193 Os (T 1/2 ∼ 30h) were investigated. For that purpose, ∼ 5 mg samples of 99%-enriched 192 Os were irradiated under a thermal neutron flux of ∼ 10 12 s -1 and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma (θ ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2 +; moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio (δ Ln+1 /L n ) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in 193 Ir. (author)

Reconstruction of B hadron decays at DELPHI

CERN Document Server

Salmi, Laura Tiina Maria

2006-01-01

This thesis describes three analyses related to heavy quarks. The analysis with the largest impact is the extraction of parameters of heavy quark decays using the lepton energy spectrum and the hadronic mass spectrum in semileptonic B decays. The extraction of the parameters allows to test the framework used to theoretically describe the decay of heavy mesons, and more accurate knowledge of the parameter values results in greater accuracy in the determination of the element |Vcb| of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix. The determination described in this thesis is important, since it is so far the only one where the full lepton energy spectrum has been used. The other determinations are based on using only a part of the spectrum. The first extraction of the parameters in the kinetic mass scheme was based on the statistical moments of the lepton energy spectrum and hadronic mass spectrum measured using the data collected at delphi. In the second analysis, the angular distribution of fragmen...

Search for CP violation in $D^{+} \\to K^{-}K^{+}\\pi^{+}$ decays

CERN Document Server

Aaij, R.; Adinolfi, M.; Adrover, C.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A.A.; Amato, S.; Amhis, Y.; Anderson, J.; Appleby, R.B.; Aquines Gutierrez, O.; Archilli, F.; Arrabito, L.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Bachmann, S.; Back, J.J.; Bailey, D.S.; Balagura, V.; Baldini, W.; Barlow, R.J.; Barschel, C.; Barsuk, S.; Barter, W.; Bates, A.; Bauer, C.; Bauer, Th.; Bay, A.; Bediaga, I.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Benayoun, M.; Bencivenni, G.; Benson, S.; Benton, J.; Bernet, R.; Bettler, M.O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bizzeti, A.; Bjornstad, P.M.; Blake, T.; Blanc, F.; Blanks, C.; Blouw, J.; Blusk, S.; Bobrov, A.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Bowcock, T.J.V.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Brisbane, S.; Britsch, M.; Britton, T.; Brook, N.H.; Brown, H.; Buchler-Germann, A.; Burducea, I.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Caicedo Carvajal, J.M.; Callot, O.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cattaneo, M.; Charles, M.; Charpentier, Ph.; Chiapolini, N.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P.E.L.; Clemencic, M.; Cliff, H.V.; Closier, J.; Coca, C.; Coco, V.; Cogan, J.; Collins, P.; Constantin, F.; Conti, G.; Contu, A.; Cook, A.; Coombes, M.; Corti, G.; Cowan, G.A.; Currie, R.; D'Almagne, B.; D'Ambrosio, C.; David, P.; De Bonis, I.; De Capua, S.; De Cian, M.; De Lorenzi, F.; De Miranda, J.M.; De Paula, L.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Degaudenzi, H.; Deissenroth, M.; Del Buono, L.; Deplano, C.; Deschamps, O.; Dettori, F.; Dickens, J.; Dijkstra, H.; Diniz Batista, P.; Donleavy, S.; Dordei, F.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dupertuis, F.; Dzhelyadin, R.; Eames, C.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; van Eijk, D.; Eisele, F.; Eisenhardt, S.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; d'Enterria, D.G.; Esperante Pereira, D.; Esteve, L.; Falabella, A.; Fanchini, E.; Farber, C.; Fardell, G.; Farinelli, C.; Farry, S.; Fave, V.; Fernandez Albor, V.; Ferro-Luzzi, M.; Filippov, S.; Fitzpatrick, C.; Fontana, M.; Fontanelli, F.; Forty, R.; Frank, M.; Frei, C.; Frosini, M.; Furcas, S.; Gallas Torreira, A.; Galli, D.; Gandelman, M.; Gandini, P.; Gao, Y.; Garnier, J-C.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauvin, N.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gibson, V.; Gligorov, V.V.; Gobel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Grabalosa Gandara, M.; Graciani Diaz, R.; Granado Cardoso, L.A.; Grauges, E.; Graziani, G.; Grecu, A.; Gregson, S.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Haefeli, G.; Haen, C.; Haines, S.C.; Hampson, T.; Hansmann-Menzemer, S.; Harji, R.; Harnew, N.; Harrison, J.; Harrison, P.F.; He, J.; Heijne, V.; Hennessy, K.; Henrard, P.; Hernando Morata, J.A.; van Herwijnen, E.; Hicks, E.; Hofmann, W.; Holubyev, K.; Hopchev, P.; Hulsbergen, W.; Hunt, P.; Huse, T.; Huston, R.S.; Hutchcroft, D.; Hynds, D.; Iakovenko, V.; Ilten, P.; Imong, J.; Jacobsson, R.; Jaeger, A.; Jahjah Hussein, M.; Jans, E.; Jansen, F.; Jaton, P.; Jean-Marie, B.; Jing, F.; John, M.; Johnson, D.; Jones, C.R.; Jost, B.; Kandybei, S.; Karacson, M.; Karbach, T.M.; Keaveney, J.; Kerzel, U.; Ketel, T.; Keune, A.; Khanji, B.; Kim, Y.M.; Knecht, M.; Koblitz, S.; Koppenburg, P.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kruzelecki, K.; Kucharczyk, M.; Kukulak, S.; Kumar, R.; Kvaratskheliya, T.; La Thi, V.N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R.W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Le Gac, R.; van Leerdam, J.; Lees, J.P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Li, L.; Li Gioi, L.; Lieng, M.; Liles, M.; Lindner, R.; Linn, C.; Liu, B.; Liu, G.; Lopes, J.H.; Lopez Asamar, E.; Lopez-March, N.; Luisier, J.; Machefert, F.; Machikhiliyan, I.V.; Maciuc, F.; Maev, O.; Magnin, J.; Malde, S.; Mamunur, R.M.D.; Manca, G.; Mancinelli, G.; Mangiafave, N.; Marconi, U.; Marki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martin, L.; Martin Sanchez, A.; Martinez Santos, D.; Martins Tostes, D.; Massafferri, A.; Mathe, Z.; Matteuzzi, C.; Matveev, M.; Maurice, E.; Maynard, B.; Mazurov, A.; McGregor, G.; McNulty, R.; Mclean, C.; Meissner, M.; Merk, M.; Merkel, J.; Messi, R.; Miglioranzi, S.; Milanes, D.A.; Minard, M.N.; Molina Rodriguez, J.; Monteil, S.; Moran, D.; Morawski, P.; Mountain, R.; Mous, I.; Muheim, F.; Muller, K.; Muresan, R.; Muryn, B.; Musy, M.; Mylroie-Smith, J.; Naik, P.; Nakada, T.; Nandakumar, R.; Nardulli, J.; Nasteva, I.; Nedos, M.; Needham, M.; Neufeld, N.; Nguyen-Mau, C.; Nicol, M.; Nies, S.; Niess, V.; Nikitin, N.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Orlandea, M.; Otalora Goicochea, J.M.; Owen, P.; Pal, B.; Palacios, J.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Parkes, C.; Parkinson, C.J.; Passaleva, G.; Patel, G.D.; Patel, M.; Paterson, S.K.; Patrick, G.N.; Patrignani, C.; Pavel-Nicorescu, C.; Pazos Alvarez, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perego, D.L.; Perez Trigo, E.; Perez-Calero Yzquierdo, A.; Perret, P.; Perrin-Terrin, M.; Pessina, G.; Petrella, A.; Petrolini, A.; Pie Valls, B.; Pietrzyk, B.; Pilar, T.; Pinci, D.; Plackett, R.; Playfer, S.; Plo Casasus, M.; Polok, G.; Poluektov, A.; Polycarpo, E.; Popov, D.; Popovici, B.; Potterat, C.; Powell, A.; du Pree, T.; Prisciandaro, J.; Pugatch, V.; Puig Navarro, A.; Qian, W.; Rademacker, J.H.; Rakotomiaramanana, B.; Rangel, M.S.; Raniuk, I.; Raven, G.; Redford, S.; Reid, M.M.; dos Reis, A.C.; Ricciardi, S.; Rinnert, K.; Roa Romero, D.A.; Robbe, P.; Rodrigues, E.; Rodrigues, F.; Rodriguez Perez, P.; Rogers, G.J.; Roiser, S.; Romanovsky, V.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Sabatino, G.; Saborido Silva, J.J.; Sagidova, N.; Sail, P.; Saitta, B.; Salzmann, C.; Sannino, M.; Santacesaria, R.; Santamarina Rios, C.; Santinelli, R.; Santovetti, E.; Sapunov, M.; Sarti, A.; Satriano, C.; Satta, A.; Savrie, M.; Savrina, D.; Schaack, P.; Schiller, M.; Schleich, S.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.H.; Schwemmer, R.; Sciubba, A.; Seco, M.; Semennikov, A.; Senderowska, K.; Sepp, I.; Serra, N.; Serrano, J.; Seyfert, P.; Shao, B.; Shapkin, M.; Shapoval, I.; Shatalov, P.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, O.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Skottowe, H.P.; Skwarnicki, T.; Smith, A.C.; Smith, N.A.; Sobczak, K.; Soler, F.J.P.; Solomin, A.; Soomro, F.; Souza De Paula, B.; Spaan, B.; Sparkes, A.; Spradlin, P.; Stagni, F.; Stahl, S.; Steinkamp, O.; Stoica, S.; Stone, S.; Storaci, B.; Straticiuc, M.; Straumann, U.; Styles, N.; Subbiah, V.K.; Swientek, S.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teodorescu, E.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Topp-Joergensen, S.; Tran, M.T.; Tsaregorodtsev, A.; Tuning, N.; Ubeda Garcia, M.; Ukleja, A.; Urquijo, P.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; Velthuis, J.J.; Veltri, M.; Vervink, K.; Viaud, B.; Videau, I.; Vieira, D.; Vilasis-Cardona, X.; Visniakov, J.; Vollhardt, A.; Voong, D.; Vorobyev, A.; Voss, H.; Wacker, K.; Wandernoth, S.; Wang, J.; Ward, D.R.; Webber, A.D.; Websdale, D.; Whitehead, M.; Wiedner, D.; Wiggers, L.; Wilkinson, G.; Williams, M.P.; Williams, M.; Wilson, F.F.; Wishahi, J.; Witek, M.; Witzeling, W.; Wotton, S.A.; Wyllie, K.; Xie, Y.; Xing, F.; Yang, Z.; Young, R.; Yushchenko, O.; Zavertyaev, M.; Zhang, F.; Zhang, L.; Zhang, W.C.; Zhang, Y.; Zhelezov, A.; Zhong, L.; Zverev, E.; Zvyagin, A.

2011-01-01

A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \\to K^- K^+\\pi^+$ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb$^{-1}$. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.

New Decay Studies of 66Ga

Science.gov (United States)

Kumar, Suresh; Ahmad, I.; Carpenter, M. P.; Chen, J.; Greene, J. P.; Kondev, F. G.; Zhu, S.

2014-03-01

High-energy γ rays with energies up to 5.0 MeV are emitted in the radioactive decay of 66Ga (T1/2 = 9.49 h). Thus, this radionuclide appears to be a suitable candidate for energy and efficiency calibrations of high-resolution, γ-ray spectrometers that are employed in studies of very neutron-rich nuclei which have large Qβ values. In addition, accurate emission probabilities of this isotope are of interest to medical imaging applications, owing to the existence of large β+ decay branches, which need to be characterized with better accuracy. Decay studies of 66Ga were initiated using the γ-ray spectroscopy technique. The source was produced by means of the 66Zn(p,n) reaction at a beam energy of 12 MeV. Singles and γ - γ coincidences measurements were carried out using a single Ge detector and Gammasphere, respectively. The previously known 66Ga decay scheme was extended and many new γ rays were placed in the daughter nuclide 66Zn. The work at ANL was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. S. Kumar acknowledges support from the Indo-US Science and Technology Forum for the award of a Research Fellowship.

Extensions to COGEND for ENDF/B-V output of spontaneous fission decay data

International Nuclear Information System (INIS)

Tobias, A.

1978-06-01

The computer code COGEND, used to produce ENDF/B-IV or -V format nuclear decay scheme data, has been modified in order to extend its range of application. Details are given of the additional facilities which permit the handling of spontaneous fission decay data including any associated continuous spectra. In order to accommodate these additional features it is necessary to increase the core region by 4 kilobytes. (author)

Effect of the upper-level decay on the resonantly enhanced four-wave mixing in a modified double-Λ system

International Nuclear Information System (INIS)

Kien, Fam Le; Hakuta, K.

2004-01-01

We study the continuous resonant four-wave mixing in a medium of atoms with a modified double-Λ level configuration. Under the far-off-resonance condition for a pair of levels, we reduce the five-level scheme to an effective three-level scheme, with a two-photon coupling between the two lower levels. We derive the exact steady-state solution to the density-matrix equations for the reduced scheme and obtain the wave-mixing equations for the fields in the continuous-wave regime. We show that the upper-level decay may substantially affect the resonantly enhanced wave-mixing process. We demonstrate that this decay shortens the conversion cycle rather than prolongs it

Approximation of the decay of fission and activation product mixtures

International Nuclear Information System (INIS)

Henderson, R.W.

1991-01-01

The decay of the exposure rate from a mixture of fission and activation products is a complex function of time. The exact solution of the problem involves the solution of more than 150 tenth order Bateman equations. An approximation of this function is required for the practical solution of problems involving multiple integrations of this function. Historically this has been a power function, or a series of power functions, of time. The approach selected here has been to approximate the decay with a sum of exponential functions. This produces a continuous, single valued function, that can be made to approximate the given decay scheme to any desired degree of closeness. Further, the integral of the sum is easily calculated over any period. 3 refs

NNLO QCD corrections to associated W H production and H →b b ¯ decay

Science.gov (United States)

Caola, Fabrizio; Luisoni, Gionata; Melnikov, Kirill; Röntsch, Raoul

2018-04-01

We present a computation of the next-to-next-to-leading-order (NNLO) QCD corrections to the production of a Higgs boson in association with a W boson at the LHC and the subsequent decay of the Higgs boson into a b b ¯ pair, treating the b quarks as massless. We consider various kinematic distributions and find significant corrections to observables that resolve the Higgs decay products. We also find that a cut on the transverse momentum of the W boson, important for experimental analyses, may have a significant impact on kinematic distributions and radiative corrections. We show that some of these effects can be adequately described by simulating QCD radiation in Higgs boson decays to b quarks using parton showers. We also describe contributions to Higgs decay to a b b ¯ pair that first appear at NNLO and that were not considered in previous fully differential computations. The calculation of NNLO QCD corrections to production and decay sub-processes is carried out within the nested soft-collinear subtraction scheme presented by some of us earlier this year. We demonstrate that this subtraction scheme performs very well, allowing a computation of the coefficient of the second-order QCD corrections at the level of a few per mill.

GRAP, Gamma-Ray Level-Scheme Assignment

International Nuclear Information System (INIS)

Franklyn, C.B.

2002-01-01

1 - Description of program or function: An interactive program for allocating gamma-rays to an energy level scheme. Procedure allows for searching for new candidate levels of the form: 1) L1 + G(A) + G(B) = L2; 2) G(A) + G(B) = G(C); 3) G(A) + G(B) = C (C is a user defined number); 4) L1 + G(A) + G(B) + G(C) = L2. Procedure indicates intensity balance of feed and decay of each energy level. Provides for optimization of a level energy (and associated error). Overall procedure allows for pre-defining of certain gamma-rays as belonging to particular regions of the level scheme, for example, high energy transition levels, or due to beta- decay. 2 - Method of solution: Search for cases in which the energy difference between two energy levels is equal to a gamma-ray energy within user-defined limits. 3 - Restrictions on the complexity of the problem: Maximum number of gamma-rays: 999; Maximum gamma ray energy: 32000 units; Minimum gamma ray energy: 10 units; Maximum gamma-ray intensity: 32000 units; Minimum gamma-ray intensity: 0.001 units; Maximum number of levels: 255; Maximum level energy: 32000 units; Minimum level energy: 10 units; Maximum error on energy, intensity: 32 units; Minimum error on energy, intensity: 0.001 units; Maximum number of combinations: 6400 (ca); Maximum number of gamma-ray types : 127

Decay of oak Wood provoked by fungus Stereum hirsutum (Willd. ex Fr. S. F. Gray. and its' essential physiological requirements

Directory of Open Access Journals (Sweden)

Mirić Milenko

2005-01-01

Full Text Available White rot fungi usually decompose cell walls of attacked wood destroying tissue elements (i.e. parenchyma cells, wood fibres, tension wood, tracheas etc in different amount, depending to wood-species as well as to its' zones. Different fungi secrete specific enzymes that are responsible for certain damages. As consequence, the wood structure use to be significantly and unfixable decomposed and changed. Microscopical analyses that have been run provided clear and indicative information relating to effects of fungal activity on wood tissue. Physiological requirements of fungi are for shore of the highest importance in understanding of mechanism of decaying process in the wood. The most important factors as like temperature and concentration of H ions, as well as main nutrients as sources of carbon, nitrogen and phosphorus can affect the behaviour of wood decaying fungi. The impacts of these factors on the growth and production on mycelial mass of Stereum hirsutum (Willd. ex Fr. S.F. Gray., have been investigated. This fungus is one of the most frequent appearing on the Sessile- and Pedunculate Oak weakened trees or felled logs, behaving as parasite as well as saprophyte. As a causer of Oak sapwood white rot S. hirsutum causes significant damages of wood at forest- as well as at industrial storages.

Level Scheme of 223Fr

International Nuclear Information System (INIS)

Gaeta, R.; Gonzalez, J.A.; Gonzalez, L.; Roldan, C.

1972-01-01

A study has been made of the decay of 2 27 Ac at levels of 223 F r, means of alpha Spectrometers of Si barrier detector and gamma Spectrometers of Ge(Li). The rotational bands 1/2-(541 ↓ ] , 1/2-(530 ↑ ) and 3/2-(532 ↓ ) have been identified, as well as two octupolar bands associated with the fundamental one. The results obtained indicate that the unified model is applicable in this intermediate zone of the nuclide chart. (Author) 150 refs

Study of sup 1 sup 9 sup 4 Tl sup g decay

CERN Document Server

Sudarshan, K; Tripathi, R; Goswami, A; Tomar, B S; Reddy, A V R

2003-01-01

Absolute gamma ray intensities in the decay of sup 1 sup 9 sup 4 Tl sup g have been measured following the radiochemical separation of sup 1 sup 9 sup 4 Pb produced in the reaction of sup 1 sup 9 F + sup 1 sup 8 sup 1 Ta. The (EC+beta sup +) branching ratios in the decay of sup 1 sup 9 sup 4 Tl sup g to various levels of sup 1 sup 9 sup 4 Hg were deduced. Three new levels are introduced in the decay scheme. A precise value of half life of sup 1 sup 9 sup 4 Pb (10.0+-0.4 min) is reported.

Spectroscopy of high spin states in sup(211,212,213)Fr

International Nuclear Information System (INIS)

Byrne, A.P.; Dracoulis, G.D.; Fahlander, C.; Hubel, H.; Poletti, A.R.; Stuchbery, A.E.; Gerl, J.; Davie, R.F.; Poletti, S.J.

1985-08-01

The level structures of 211 Fr, 212 Fr and 213 Fr have been observed to high spins, approx. 28(h/2π) (and excitation energies approx. 8 MeV) using a variety of gamma-ray spectroscopic techniques. The structure of these nuclides is discussed in terms of couplings of single particle states through empirical shell model calculations. Good agreement with experiment is obtained. In 212 Fr and 213 Fr core-excited configurations are required to explain the properties of the highest states. A number of long lived states were observed in each nucleus some of which decay by by enhanced E3 transitions. The E3 transition strengths are discussed

Radiative corrections in K{yields}3{pi} decays

Energy Technology Data Exchange (ETDEWEB)

Bissegger, M. [Institute for Theoretical Physics, University of Bern, Sidlerstr. 5, CH-3012 Bern (Switzerland); Fuhrer, A. [Institute for Theoretical Physics, University of Bern, Sidlerstr. 5, CH-3012 Bern (Switzerland); Physics Department, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0319 (United States); Gasser, J. [Institute for Theoretical Physics, University of Bern, Sidlerstr. 5, CH-3012 Bern (Switzerland); Kubis, B. [Helmholtz-Institut fuer Strahlen-und Kernphysik, Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany)], E-mail: kubis@itkp.uni-bonn.de; Rusetsky, A. [Helmholtz-Institut fuer Strahlen-und Kernphysik, Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany)

2009-01-01

We investigate radiative corrections to K{yields}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.

Nuclear decay scheme studies of 30-h 131Te/sup m/, 25-min 131Te/sup g/, and 55.5-min 105Cd

International Nuclear Information System (INIS)

Jackson, S.V.

1975-01-01

High-resolution Ge(Li) detectors have been used to observe γ-ray singles and coincidence spectra of 30-h 11 / 2 - , /sup 131m/Te, 25-min 3 / 2 + , and 55.5-min 5 / 2 + 105 Cd. Sources of /sup 131m/Te and /sup 131g/Te were produced by neutron irradiation of enriched 130 Te metal, and, in the case of /sup 131m/Te, were chemically purified to remove the 131 I daughter. A total of 190 and 80 γ-rays are attributed to the decays of /sup 131m/Te and /sup 131g/Te, respectively; and 174 and 77 of these transitions have been placed in a 131 I level scheme involving 52 excited states. Absolute β group intensities were determined for the transitions to 131 I levels. Spin and parity assignments were made for all observed levels. The β feeding from the 11 / 2 - /sup 131m/Te to the 7 / 2 + 131 I ground state was determined to be (5.2 +- 3.0) percent (log ft = 10.5). The isomeric transition of 11 / 2 - /sup 131m/Te to 3 / 2 + /sup 131g/Te was determined to be (22.2 +- 1.6) percent. The 6-nsec isomer in 131 I at 1797 keV has been assigned as 15 / 2 - and interpreted as a πν 1 ν 2 three quasi-particle state. Sources of 105 Cd were produced via the 106 Cd(n,2n) reaction on enriched 106 CdO using 14 MeV neutrons. A total of 274 γ-rays are attributed to the decay of 105 Cd, and 248 of these have been placed in a 105 Ag level scheme involving 50 excited states. Absolute values for the β + /EC transition intensities to 105 Ag levels were determined. The β + /EC feeding from the 5 / 2 + 105 Cd to the 7 / 2 + 25.5-keV isomeric state in 105 Ag was determined to be (51.4 +- 4.0) percent (log ft = 5.4). The experimentally determined level structures of 131 I and 105 Cd are interpreted in terms of the shell model and core excitation considerations with emphasis placed on the core coupling model and the three-particle models. (U.S.)

Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

Energy Technology Data Exchange (ETDEWEB)

Boulanger, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

1968-06-01

The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete mesurees, et les schemas de

Decay of /sup 125/Sb

Energy Technology Data Exchange (ETDEWEB)

Singh, K; Sahota, H S

1983-01-01

The 2.7 yr beta decay of /sup 125/Sb yields /sup 125/Te has been studied using Ge(Li), Si(Li) and Ge detectors and the directional correlation technique New lines at 58, 111, 642, 693 and 729 keV have been detected and fitted in the decay scheme in the already existing levels, besides the one suggested at 729 keV. The intensities of 20, 109, 111, 116, 172, 178 and 198 keV transitions have been measured more precisely than before. The ..gamma..-..gamma.. directional correlation measurements in the 208-463, 204-176 and 321-176 keV cascades have enabled to assign a uniquue spin 7/2/sup -/ to the 525 keV level. The multipole mixing ratios for the 204, 208 and 321 keV transitions have been found as M1 + (14.75 +- 3.55)%E2, M1 + (4.5 +- 2.0)%E2 and E1 + (2.70 +- 0.75)%M2, respectively.

Nuclear Structure of 124Xe Studied with β+/EC-Decay

Science.gov (United States)

Radich, A. J.; Garrett, P. E.; Allmond, J. M.; Andreoiu, C.; Ball, G. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Hackman, G.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A. T.; Leach, K. G.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E.; Starosta, K.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Wood, J. L.; Wong, J.; Williams, S. J.; Yates, S. W.

The nuclear structure of 124Xe was investigated using γ-ray spectroscopy following the β+/EC-decay of 124Cs. A very high-statistics data set was collected and γγ coincidence data was analyzed, greatly adding to the 124Xe level scheme. A new decay branch from the high-spin isomer of 124Cs was observed as well as weak E2 transitions into excited 0+ states in 124Xe. B(E2) transition strengths of such low-spin transitions are very important in determining collective properties, which are currently poorly characterized in the region of neutron-deficient xenon isotopes.

Projected study of neutronic decay of giant resonances and continuum states

International Nuclear Information System (INIS)

Blumenfeld, Y.; Chomaz, P.; Fortier, S.; Frascaria, N.; Gales, S.; Guillot, J.; Langevin, H.; Laurent, H.; Maison, J.M.; Nguyen Van Giai

1988-01-01

A project to study the decay of very excited states in nuclei is presented. A multidetector to measure these modes for excited structures situated beyond the neutron emission threshold is proposed. Coincidence experiments would allow a study of the wave functions of these elementary excitations and of the damping mechanisms in the nuclear domain. The definition of the characteristics of the system; tests to be carried out before selecting a detector; and nonscientific and nontechnical aspects of the project are also presented [fr

Level structures in 156Pm from 156Nd β - decay

International Nuclear Information System (INIS)

Sood, P.C.; Gowrishankar, R.; Sainath, M.; Singh, B.

2012-01-01

Level energies in two-quasiparticle (2qp) structures in 156 61 Pm 95 are evaluated using the phenomenological rotor-particle model for odd-odd deformed nuclei with the inclusion of the residual p-n interaction contribution. Using these results as location guides, the experimental data from a recent 156 Nd decay study are used to construct a level scheme for 156 Pm with excitation energies upto 550 keV, wherein 26 (out of 30) γ's reported in 156 Nd decay are incorporated. Spin-parities and configuration assignments are suggested for 15 levels, in addition to the two isomers, in this energy domain. These investigations point to the need for information on higher-energy γ's and on β-γ and γ-γ coincidence data from 156 Nd β-decay to confirm these assignments. (orig.)

Vector-like quarks and leptons, SU(5) ⊗ SU(5) grand unification, and proton decay

International Nuclear Information System (INIS)

Lee, Chang-Hun; Mohapatra, Rabindra N.

2017-01-01

SU(5) ⊗ SU(5) provides a minimal grand unification scheme for fermions and gauge forces if there are vector-like quarks and leptons in nature. We explore the gauge coupling unification in a non-supersymmetric model of this type, and study its implications for proton decay. The properties of vector-like quarks and intermediate scales that emerge from coupling unification play a central role in suppressing proton decay. We find that in this model, the familiar decay mode p→e + π 0 may have a partial lifetime within the reach of currently planned experiments.

Decay spectroscopy of neutron-rich nuclei around {sup 37,38}Al

Energy Technology Data Exchange (ETDEWEB)

Steiger, Konrad [Physik-Department E12, Technische Universitaet Muenchen (Germany); Collaboration: CAITEN-Collaboration

2013-07-01

An experiment at RIBF (Radioactive Isotope Beam Factory at RIKEN, Japan) investigated N=20 nuclei above {sup 29}F and the midshell region around {sup 37}Al. These nuclei were produced by relativistic projectile fragmentation of a 345 AMeV {sup 48}Ca primary beam from the superconducting ring cyclotron SRC with an average intensity of 70 pnA. The secondary cocktail beam was separated and identified with the BigRIPS fragment separator and the ZeroDegree spectrometer. The identified fragments were implanted in the CAITEN detector (Cylindrical Active Implantation Target for Efficient Nuclear-decay study). The main part of this detector is a highly segmented plastic scintillator with the shape of a hollow cylinder. To reduce background decay events the scintillator was moved axially and vertically similar to a tape-transport system. Implantations and decays were correlated in time and space. For the first time β-delayed γ-rays were measured in the neutron-rich isotopes {sup 37,38}Si (with three germanium clover detectors). From β-γ-γ coincidences partial level schemes could be constructed. The results were compared to shell model calculations and a tentative assignment for spins and parities of the experimental level schemes was possible. Significantly more precise half-lives for the implanted nuclei were measured.

Studying radiative B decays with the Atlas detector

International Nuclear Information System (INIS)

Viret, S.

2004-09-01

This thesis is dedicated to the study of radiative B decays with the ATLAS detector at the LHC (large hadron collider). Radiative decays belong to the rare decays family. Rare decays transitions involve flavor changing neutral currents (for example b → sγ), which are forbidden at the lowest order in the Standard Model. Therefore these processes occur only at the next order, thus involving penguin or box diagrams, which are very sensitive to 'new physics' contributions. The main goal of our study is to show that it would be possible to develop an online selection strategy for radiative B decays with the ATLAS detector. To this end, we have studied the treatment of low energy photons by the ATLAS electromagnetic calorimeter (ECal). Our analysis shows that ATLAS ECal will be efficient with these particles. This property is extensively used in the next section, where a selection strategy for radiative B decays is proposed. Indeed, we look for a low energy region of interest in the ECal as soon as the level 1 of the trigger. Then, photon identification cuts are performed in this region at level 2. However, a large part of the proposed selection scheme is also based on the inner detector, particularly at level 2. The final results show that large amounts of signal events could be collected in only one year by ATLAS. A preliminary significance (S/√B) estimation is also presented. Encouraging results concerning the observability of exclusive radiative B decays are obtained. (author)

Decays of 116Sb isomers to levels in 116Sn

International Nuclear Information System (INIS)

Gacsi, Z.; Raman, S.

1994-01-01

The excited states of 116 Sn were studied by means of the decays of the 15.8-min, 3 + 116 Sb ground state, and the 60.3-min, 8 - 116 Sb isomer. Over 50 γ rays were observed; these were incorporated into a level scheme consisting of 32 excited states. Except for one new level proposed at 3.986 MeV, the current study fully supports an exhaustive study of levels in 116 Sn reported earlier. The previous study was an attempt to develop a nearly ''complete'' level scheme of 116 Sn up to an excitation energy of 4.3 MeV

Critical evaluation of radioactive decay constants for 99Mo, 144Ce, 144Pr and 144Pm

International Nuclear Information System (INIS)

Grigor'yan, Yu.I.; Sokolovskij, L.L.; Chukreev, F.E.

1976-01-01

The decay schemes of 99 Mo, 144 Ce, 144 Pr, 144 Pm are reviewed on the basis of analysis of a large number of published experimental works. A knowledge of the decay constants of the first three nuclei, which are fission products, is of great importance in developing safeguards methods. Quantities characterizing the β-decay of 99 Mo, 144 Ce, 144 Pr and K-electron capture ( 144 Pm) are evaluated. Level schemes are plotted for the daughter nuclei. Evaluations are made in respect of the energies and intensities of γ-rays and conversion electrons accompanying β-decay and K-electron capture, internal conversion coefficients and transition multipolarities, level energies, spins, parities, and lifetimes of the ground and excited states of 99 Tc, 144 Pr, and 144 Nd. From the results obtained the 99 Mo- 99 Tc mass difference can be deduced and a new value of 1358.0 +- 3.0 keV is established instead of the previously used value of 1372.2 +- 3.9 keV. The analagous quantity for the nuclei 144 Pr- 144 Nd is taken as 2994.6 +- 3.2 keV instead of the value 2997.0 +- 3.0 keV. (author)

Scheme for entanglement concentration of unknown atomic entangled states by interference of polarized photons

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Yeon, Kyu-Hwang, E-mail: hfwang@ybu.edu.c, E-mail: szhang@ybu.edu.c [Department of Physics and BK21 Program for Device Physics, College of Natural Science, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of)

2010-12-14

Based on the interference effect of polarized photons, we propose a practical scheme for entanglement concentration of unknown atomic entangled states. In the scheme, two {lambda}{lambda}-type atoms belonging to different entangled pairs are individually trapped in two spatially separated cavities. By the subsequent detection of the polarized photons leaking out of the separate optical cavities, Alice and Bob as two distant parties can probabilistically extract one maximally entangled four-atom Greenberger-Horne-Zeilinger (GHZ) state from two identical partially entangled Einstein-Podolsky-Rosen (EPR) pairs. We also discuss the influence of cavity decay on the success probability of the scheme. The scheme is feasible and within the reach of current experimental technology.

Data processing in gamma spectrometry. Application to the decay schemes study; Traitement des informations en spectrometrie gamma application a l'etude de schemas de desintegration

Energy Technology Data Exchange (ETDEWEB)

Boulanger, J.P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, departement d' electronique generale, service d' instrumentation nucleaire

1968-06-01

The purpose of this thesis is the processing of the data issued from a gamma spectrometer, and its applications to the decay schemes study. The mathematical analysis of the full energy peaks, in connection with the very good resolution of semi-conductor detectors, leads to a very accurate determination of the energies. The resolution of complex spectra by the least squares method, completed by a spectra generating process, allows the calculation of branching ratios. Then, the handling of the two dimensional experiments permits the coincidence exam. For each of these methods, the calculation principle, then the systematics tests realized in order to prove their validity and to determine their application ranges as well as some experimental results appropriate to illustrate their possibilities, are presented. The energies of some nuclides, frequently used as standards have been thus measured and the decay schemes of {sup 134}Cs and {sup 110m}Ag determined precisely. (author) [French] Cette these est consacree aux methodes de traitement des informations issues d'un spectrometre {gamma}, et a leur application a l'etude des schemas de desintegration: l'analyse mathematique des pics d'absorption totale, conjuguee avec l'excellent pouvoir de resolution des detecteurs semi-conducteurs, conduit a une determination tres precise des energies. La decomposition des spectres complexes par la methode des moindres carres, completee par un procede de generation de spectres, autorise le calcul des rapports de branchement. Enfin le depouillement des experiences biparametriques permet l'examen des coincidences. Pour chacune de ces methodes, on expose le principe des calculs et les essais systematiques effectues afin d'eprouver leur validite et de definir leurs domaines d'application, ainsi que quelques resultats experimentaux propres a illustrer leurs possibilites. Les energies de quelques isotopes utilises couramment comme etalons ont ainsi ete

Stability and Convergence Analysis of Second-Order Schemes for a Diffuse Interface Model with Peng-Robinson Equation of State

KAUST Repository

Peng, Qiujin; Qiao, Zhonghua; Sun, Shuyu

2017-01-01

In this paper, we present two second-order numerical schemes to solve the fourth order parabolic equation derived from a diffuse interface model with Peng-Robinson Equation of state (EOS) for pure substance. The mass conservation, energy decay property, unique solvability and L-infinity convergence of these two schemes are proved. Numerical results demonstrate the good approximation of the fourth order equation and confirm reliability of these two schemes.

Stability and Convergence Analysis of Second-Order Schemes for a Diffuse Interface Model with Peng-Robinson Equation of State

KAUST Repository

Peng, Qiujin

2017-09-18

In this paper, we present two second-order numerical schemes to solve the fourth order parabolic equation derived from a diffuse interface model with Peng-Robinson Equation of state (EOS) for pure substance. The mass conservation, energy decay property, unique solvability and L-infinity convergence of these two schemes are proved. Numerical results demonstrate the good approximation of the fourth order equation and confirm reliability of these two schemes.

Simple schemes for generation of W-type multipartite entangled states and realization of quantum-information concentration

International Nuclear Information System (INIS)

Deng-Yu, Zhang; Shi-Qing, Tang; Li-Jun, Xie; Xiao-Gui, Zhan; Yin-Hua, Chen; Feng, Gao

2010-01-01

We propose simple schemes for generating W-type multipartite entangled states in cavity quantum electrodynamics (CQED). Our schemes involve a largely detuned interaction of Λ-type three-level atoms with a single-mode cavity field and a classical laser, and both the symmetric and asymmetric W states can be created in a single step. Our schemes are insensitive to both the cavity decay and atomic spontaneous emission. With the above system, we also propose a scheme for realizing quantum-information concentration which is the reverse process of quantum cloning. In this scheme, quantum-information originally coming from a single qubit, but now distributed into many qubits, is concentrated back to a single qubit in only one step. (general)

Conditional generation of the Greenberger-Horne-Zeilinger state of four distant atoms via cavity decay

International Nuclear Information System (INIS)

Zou, XuBo; Pahlke, K.; Mathis, W.

2003-01-01

We propose a scheme to generate a four-particle Greenberger-Horne-Zeilinger (GHZ) state of distant atoms that are trapped separately in leaky cavities. This scheme uses cavity decay to inject photons into a setup of optical devices that consist of a symmetric series of beam splitters and photon detectors. Photon detection on the output modes of the beam splitters projects the atom-cavity-system state onto the GHZ state. It is briefly pointed out that this scheme can be extended to generate GHZ states of 4m atoms

System reliability assessment via sensitivity analysis in the Markov chain scheme

International Nuclear Information System (INIS)

Gandini, A.

1988-01-01

Methods for reliability sensitivity analysis in the Markov chain scheme are presented, together with a new formulation which makes use of Generalized Perturbation Theory (GPT) methods. As well known, sensitivity methods are fundamental in system risk analysis, since they allow to identify important components, so to assist the analyst in finding weaknesses in design and operation and in suggesting optimal modifications for system upgrade. The relationship between the GPT sensitivity expression and the Birnbaum importance is also given [fr

IMPECC, new 4 π β γ coincidence system

International Nuclear Information System (INIS)

Bouchard, J.; Chauvenet, B.; Vatin, R.

1988-05-01

The new 4 π β γ coincidence system IMPECC which uses an extensible dead time circuit common to both channels is described. Correction formulae which take into account the particularities of the electronics are also presented. The use of two ADC's and the symmetry in the two channels gives us a very powerful instrument when measuring complex decay scheme radionuclides [fr

A new million-channel analyzer for complex nuclear spectroscopy studies and its application in measurements of the β decay of 149Pr

International Nuclear Information System (INIS)

Tenten, W.

1978-11-01

A million-channel analyzer with CAMAC instrumentation and PDP-11 control computer was developed and tested using the case of the β decay of 149 Pr and the γ decays of 149 Nd. A level scheme for 149 Nd was developed. (WL) [de

Scheme for the generation of three-atom Greenberger-Horne-Zeilinger states and teleportation of entangled atomic states

International Nuclear Information System (INIS)

Ye Liu; Guo Guangcan

2003-01-01

A scheme is proposed for the preparation of Greenberger-Horne-Zeilinger states for three atoms and for teleportation of an entangled atom pair by use of the triplet in cavity QED. The cavity is only virtually excited, and thus the scheme is insensitive to the cavity field states and the cavity decay. The preparation and teleportation can be achieved in a simple way

Measurement of the Exclusive and Inclusive Branching Fractions of $B^{0}_{s} \\to D^{(*)+}_{s}D^{(*)-}_{s}$ Decays at CDF and its Implications on the Decay Width Difference in the $B^{0}_{s}-B^{-0}_{s}$ Meson System

Energy Technology Data Exchange (ETDEWEB)

Horn, Dominik [Karlsruhe Inst. of Technology (KIT) (Germany)

2011-01-01

The purpose of this thesis is threefold: Firstly, new measurements of both the exclusive and semi-inclusive partial decay widths of $B^{0}_{s} \\to D^{(*)+}_{s}D^{(*)-}_{s}$ meson decays are presented. Secondly, the feasibility of extracting the unknown polarization components in $B^{0}_{s} \\to D^{(*)+}_{s}D^{(*)-}_{s}$ by partial reconstruction of this pseudo-scalar to vector-vector decay in a Monte Carlo driven analysis scheme is studied. Finally, based on the suggestions contributed by the theory community this study discusses how a measurement of the branching fraction of semi-inclusive decays $B^{0}_{s} \\to D^{(*)+}_{s}D^{(*)-}_{s}$ can contribute to gain insight about the relative decay width di erence in the B$0\\atop{s}$--B$0\\atop{s}$ meson system.

β Decay processes of neutron-rich isotopes of sodium and magnesium

International Nuclear Information System (INIS)

Guillemaud, D.

1982-01-01

The γ and n activities from the β decay of Na isotopes up to 34 Na, which are formed in high-energy fragmentation and analysed through mass-spectrometry techniques, are observed as well as those from their Mg descendants. Their intensities Isub(γ) and Isub(β) are measured; some radioactive half lives are determined. Delayed-neutron branching ratios Pn are measured. The existence of 35 Na is for the first time indicated. The position of the first excited 2 + level is taken as an indication of a stronger deformation for that isotope [fr

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

International Nuclear Information System (INIS)

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

2016-01-01

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 >150 km/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. - Highlights: • SRIM was used to study the alpha particle penetration depth and efficiency. • Correlation between thickness of decayable foil and propulsion force was established. • With the hypothesis of SAND, the travel time to Mars may be shortened to <20 days.

Radiative corrections of semileptonic hyperon decays Pt. 1

International Nuclear Information System (INIS)

Margaritisz, T.; Szegoe, K.; Toth, K.

1982-07-01

The beta decay of free quarks is studied in the framework of the standard SU(2) x U(1) model of weak and electromagnetic interactions. The so-called 'weak' part of radiative corrections is evaluated to order α in one-loop approximation using a renormalization scheme, which adjusts the counter terms to the electric charge, and to the mass of the charged and neutral vector bosons, Msub(w) and Msub(o), respectively. The obtained result is, to a good approximation, equal with the 'weak' part of radiative corrections for the semileptonic decay of any hyperon. It is shown in the model that the methods, which work excellently in case of the 'weak' corrections, do not, in general, provide us with the dominant part of the 'photonic' corrections. (author)

A background free double beta decay experiment

International Nuclear Information System (INIS)

Giomataris, I

2011-01-01

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

Contribution to study of effects consecutive to alpha decay of uranium 238 in some uranium compounds and uranium ores

International Nuclear Information System (INIS)

Ordonez-Regil, E.

1985-06-01

The consequences of alpha decay of 238 U in uranium compounds and in uranium bearing ores have been examined in two ways: leaching of 234 Th and determination of the activity ratio of 234 U and 238 U. The results have been interpreted mainly in terms of the ''hot'' character of the nascent 234 Th atoms [fr

Investigation of octupole deformations in the Fr217 nucleus by yrast spectroscopy

International Nuclear Information System (INIS)

Hulne, S.

1988-01-01

The spectroscopic characteristics of the yrast levels of Fr217 are determined. The level scheme up to a value of J = (39/2 + ) for angular momentum and parity is established. The production of the Fr217 nucleus in a heavy ion collision reaction was only possible by using a radioactive Pb210 target. The method for preparing the target is described. The Fr217 nucleus belongs to the category of nuclei showing octupole effects. Mass A = 217 seems to be the lower limit of the region where these effects occur [fr

$\\beta$-decay study of neutron-rich Tl and Pb isotopes

CERN Multimedia

It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

Nuclear-decay studies of neutron-rich rare-earth nuclides

International Nuclear Information System (INIS)

Chasteler, R.M.

1990-01-01

Neutron-rich rare-earth nuclei were produced in multinucleon transfer reactions of 170 Er and 176 Yb projectiles on nat W targets at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decays properties studied at the on-line mass separation facility OASIS. Two unknown isotopes, 169 Dy (t 1/2 = 39 ± 8 s) and 174 Er(t 1/2 = 3.3 ± 0.2 m) were discovered and their decay characteristics determined. The decay schemes for two previously identified isotopes, 168 Dy (t 1/2 = 8.8 ± 0.3 m) and 171 Ho (t 1/2 = 55 ± 3 s), were characterized. Evidence for a new isomer of 3.0 m 168 Ho g , 168 Ho m (t 1/2 = 132 ± 4 s) which decays by isomeric transition (IT) is presented. Beta particle endpoint energies were determined for the decay of 168 Ho g , 169 Dy, 171 Ho, and 174 Er, the resulting Qβ-values are: 2.93 ± 0.03, 3.2 ± 0.3, 3.2 ± 0.6, and 1.8 ± 0.2 MeV, respectively. These values were compared with values calculated using recent atomic mass formulae. Comparisons of various target/ion source geometries used in the OASIS mass separator facility for these multinucleon transfer reactions were performed. 73 refs., 40 figs., 11 tabs

Physical distributions of radon decay chain activities in air

International Nuclear Information System (INIS)

Rolle, R.

2004-01-01

The distribution of short-lived radon decay chain activities in air - in time, space and on aerosols - determines their exposure potential and measurement thereof. The radioactive decay constants and flow variables in a flow system combine, yielding activity concentration distributions and ratios of concentrations characteristic of the flow scheme, its source(s) and sink(s). The clock of 'internal' decay constants allows the unraveling of characteristics of the flow scheme from activity concentration measurements of individual members of a decay chain. Basic flow string calculations are shown. These can be assembled to define or simulate concentrations in a single- or multiple-compartment flow network. Response calculations to single- and multiple-step, or continuous changes in sources and sinks yield time-, spatial- and attachment-distributions. For the short-lived 222 Rn and 212 Pb decay chains the decay constants of the shorter-lived progeny in relation to the parent impose air activity ratios on successive chain members. Ratio limits had been used in the past to improve older grab-sampling- or integral gross-alpha measurement procedures for assessing exposure level. Assessment of individual concentrations, ratios and their distributions enables unravelling of dynamic flow systems, with restriction from the range of the parameters of flow and decay. An activity measuring instrument by itself represents a flow system with a response time distribution. Instrument response correction during continuous or quasi-continuous sampling and continuous spectrometric measurement allows far more accurate time-resolved measurement evaluation of continuously varying air concentrations, than previously attainable. Strong diurnal or even shorter (≤ 1 hr) changes probably are the norm in indoor and outdoor air activity concentrations. A mere average response evaluation, as used in steady state instrument calibration, and using less efficient instruments, is usually inadequate

Decay properties of some neutron-rich praseodymium isotopes

International Nuclear Information System (INIS)

Skarnemark, G.; Aronsson, P.O.; Stender, E.; Trautmann, N.; Kaffrell, N.; Bjoernstad, T.; Kvale, E.; Skarestad, M.

1976-01-01

Neutron-rich Pr isotopes produced in the thermal neutron-induced fission of 235 U have been investigated by means of γ-γ coincidence experiments. The nuclides have been separated from the fission product mixture, using the fast chemical separation system SISAK in connection with a gas jet recoil transport system. The results include assignments of several new γ-ray energies and partial decay schemes for 147 Pr, 148 Pr, 149 Pr and 150 Pr. (orig.) [de

Levels in 45K and 46K excited by the β decay of 45Ar and 46Ar

International Nuclear Information System (INIS)

Huck, A.; Klotz, G.; Knipper, A.; Miehe, C.; Walter, G.

1979-01-01

The nuclides 45 Ar and 46 Ar have been produced by spallation reactions on vanadium targets at Esub(p)=600MeV. The subsequent decays to 45 K and 46 K states have been studied. An intensity of 98.6+-0.6% was measured for the β transition of the 1.94MeV state in 46 K. A decay scheme involving 13 β branches has been established for 45 Ar, and the corresponding log values have been deduced. Eleven states are reported for the first time in the decay scheme of 45 Ar 1.42, 1.47, 1.72, 2.52, 2.57, 2.75, 3.31, 3.99, 4.04, 4.36 and 4.57MeV. From the lifetime, tau=4.6+-0.6ns, deduced from γ-γ delayed coincidences, the angular momentum of the 1081keV level has been established as (7/2) - on the basis of the transition strength of its γ decay. A survey on the 1fsub(7/2)→1dsub(3/2)M2 transition in odd K nuclei is presented and the observed hindrance factors are discussed

Inclusive weak decays of charmed mesons

International Nuclear Information System (INIS)

Matthews, C.G.

1993-01-01

Inclusive analysis provide a different insight into the understanding of weak decay physics. This thesis experimentally determines inclusive decay predictions of charmed D mesons. Exclusive decay predictions are also used from a variety of theoretical models to make predictions about inclusive properties. Both experimental and theoretical realms benefit from the new techniques presented in this thesis. Inclusive properties derived are the multiplicity distributions, average multiplicities and inclusive branching ratios of charged particles, charged and neutral kaons, and charged pions. The center-of-mass momentum spectra of charged and neutral kaons are also obtained. Additionally, in the theoretical realm only, the inclusive properties of neutral pions, and the center-of-mass momentum spectra of charged and neutral pions are determined. The experimental analysis, which uses data from the mark II experiment at the Stanford Linear Accelerator Center, employs an unfold technique utilizing fold matrices to obtain the charged particle and kaon properties. A new enhanced unfold technique involving fold tensors obtains the first-ever results for the inclusive charged pion properties. The average strange quark contents and the average charged lepton multiplicities of the D + , D 0 and D + 8 are also presented. In the theoretical analysis, the exclusive decay mode predictions from the factorization model for Bauer, Stech and Wirbel; the quark diagram scheme of Chau and Cheng; and the QCD sum rules model of Block and Shifman are processed to determine inclusive predictions will lead to a better understanding of the model. The thesis also derives inclusive predictions from the D meson exclusive branching ratios compiled by the Particle Data Group

Next-to-leading order prediction for the decay μ→e (e{sup +}e{sup −}) νν̄

Energy Technology Data Exchange (ETDEWEB)

Fael, M.; Greub, C. [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,CH-3012 Bern (Switzerland)

2017-01-19

We present the differential decay rates and the branching ratios of the muon decay with internal conversion, μ→e (e{sup +}e{sup −}) νν̄, in the Standard Model at next-to-leading order (NLO) in the on-shell scheme. This rare decay mode of the muon is among the main sources of background to the search for μ→eee decay. We found that in the phase space region where the neutrino energies are small, and the three-electron momenta have a similar signature as in the μ→eee decay, the NLO corrections decrease the leading-order prediction by about 10−20% depending on the applied cut.

Convergence of numerical schemes suitable for two dimensional nonlinear convection: application to the coupling of modes in a plasma

International Nuclear Information System (INIS)

Boukadida, T.

1988-01-01

The compatibility between accuracy and stability of the quasilinear equations is studied. Three stuations are analyzed: the discontinuous P-1 approximation of the first order quasilinear equation, the two dimensional version of the Lax-Friedrichs scheme and the coupling of modes in a plasma. For the one dimensional case, the proposed scheme matches the available data. In the two dimensional case, tests to show the explosion condition are performed. This investigation can be applied in laser-matter interactions, nonlinear optics and in many fields of physics [fr

β- decay of 150Ce to odd-odd 150Pr

International Nuclear Information System (INIS)

Kojima, Yasuaki; Shibata, Michihiro; Kosuga, Kazuto; Shima, Yosuke; Taniguchi, Akihiro; Hayashi, Hiroaki

2015-01-01

The β - decay of 150 Ce having a half-life of 6.05(7) s produced by the thermal-neutron-induced fission of 235 U has been studied using the on-line isotope separator at the Kyoto University Research Reactor. A decay scheme containing 18 excited levels and 55 γ-rays was constructed from γ-ray singles and γ-γ coincidence measurements. Of these, 9 levels and 37 γ-rays were newly placed. The dominant β-feeding observed at the 110 keV level of 150 Pr was found to be an allowed unhindered spin-flip transition. On the basis of the systematics of the neighboring nuclides, the Gallagher-Moszkowski coupling rules, and the selection rules for the β-decay of deformed nuclei, the Nilsson configurations of the ground and 110 keV states in 150 Pr were newly proposed to be π5/2 + [413]-ν3/2 - [521] and π5/2 - [532]-ν3/2 - [532], respectively. (author)

Beta decay of 30Na: experiment and theory

International Nuclear Information System (INIS)

Baumann, P.; Dessagne, P.; Huck, A.; Klotz, A.; Knipper, A.; Miehe, C.; Ramdane, M.; Walter, G.; Marguier, G.; Poves, A.

1988-01-01

The 30 Na β decay was studied on-line by means of mass-separation techniques. Gamma-ray, gamma-gamma, neutron-gamma spectra, neutron time-of-flight singles and γ-coincidence measurements, were registered. High-energy neutron branches (E n >2 MeV) were found complementing previouly reported data. A 30 Na β-decay scheme to 30 Mg bound and unbound states is established. The distribution of the transition strength as a function of the excitation energy for particle-unbound levels in 30 Mg is compared to shell-model calculations performed in the 0-12 MeV excitation energy range. An overall renormalization yields a B(GT) quenching factor of 0.28 substantially lower than generally observed in this mass region. Three levels in 29 Mg which are strongly populated via the 1n-channel are related to negative parity intruder states

New data on excited level scheme of 73Ge nucleus

International Nuclear Information System (INIS)

Kosyak, Yu.G.; Kaipov, D.K.; Chekushina, L.V.

1990-01-01

New data on the scheme of 73 Ge decay obtained by the method of reactor fast neutron inelastic scattering are presented. γ-Spectra from reaction 73 Ge(n, n'γ) 73 Ge at the angles of 90 and 124 deg of relatively incident neutron beam have been measured. Experimental populations of the levels are studied. 29 new γ-transitions have been identified, two new levels have been introduced

Nuclear decay data for dosimetry calculation. Revised data of ICRP Publication 38

International Nuclear Information System (INIS)

Endo, Akira; Yamaguchi, Yasuhiro

2005-02-01

New nuclear decay data used for dose calculation have been compiled for 1034 radionuclides, which are significant in medical, environmental and occupational exposures. The decay data were assembled from decay data sets of the Evaluated Nuclear Structure Data File (ENSDF), the latest version as of 2003. Basic nuclear properties in the ENSDF that are particularly important for calculating energies and intensities of radiations were examined and updated by referring to UNBASE2003/AME2003, the database for nuclear and decay properties of nuclides. In addition, modification of incomplete ENSDF was done for their format errors, level schemes, normalization records, and so on. The energies and intensities of emitted radiations by the nuclear decay and the subsequent atomic process were computed from the ENSDF using the computer code EDISTR04. EDISTR04 is an enhanced version of EDISTR used for assembling ICRP Publication 38 (ICRP38), and incorporates updates of atomic data and computation methods for calculating atomic radiations and spontaneous fission radiations. Quality assurance of the compiled data has been made by comparisons with various experimental data and decay databases prepared from different computer codes and data libraries. A package of the data files, called DECDC2 (Nuclear DECay Data for Dosimetry Calculation, Version 2), will succeed ICRP38 that has been used extensively in dose calculation and will be utilized in various fields. (author)

New physics effects on CP violation in B decays

International Nuclear Information System (INIS)

Nir, Y.

1993-01-01

The author reviews new physics effects on CP violation in B decays. In chapter 2 he introduces the formalism, and discusses the Standard Model picture of CP violation in B decays, with special emphasis on the cleanliness of the predictions. Chapter 3 gives a general discussion of new physics effects: he points out the ingredients in the analysis that are sensitive to new physics and deduces the type of new physics that is most likely to modify the Standard Model predictions. Explicit examples are given in chapter 4: a model with Z-mediated flavor changing neutral currents demonstrates in which ways the new physics will manifest itself in CP asymmetries in B decays; a supersymmetric model with open-quotes quark-squark alignmentclose quotes mechanism shows that supersymmetry may affect CP asymmetries in B decays, even though the minimal supersymmetric Standard Model does not; multi-scalar models may affect the asymmetries even in the absence of new CP violating phases; schemes for quark mass matrices will be crucially tested by the CP asymmetries. In chapter 5 he explains how, if deviations from the Standard Model predictions are measured, one will be able to learn detailed features of the New Physics that is responsible for that

Structure of doubly-odd nucleus 184Ir from the decay of 184Pt

International Nuclear Information System (INIS)

Ben Braham, A.; Bourgeois, C.; Kilcher, P.; Roussiere, B.; Sauvage, J.; Kreiner, A.J.; Porquet, M.G.

1987-01-01

States of 184 Ir populated through the β + /EC decay of 184 Pt, were studied using mass-separated sources and on-line γ-ray and e - spectroscopy techniques. A rather complete low-spin level scheme is established. Negative and positive parity structures are interpreted within the two-quasiparticle-plus-rotor model

Nuclear Data Sheets for A=217

Energy Technology Data Exchange (ETDEWEB)

Kondev, F. G.; McCutchan, E. A.; Singh, B.; Banerjee, K.; Bhattacharya, S.; Chakraborty, A.; Garg, S.; Jovancevic, N.; Kumar, S.; Rathi, S. K.; Roy, T.; Lee, J.; Shearman, R.

2018-01-01

The evaluated spectroscopic data are presented for 12 known nuclides with A=217 (Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa, U). For Tl-217, Pb-217, Pa-217, and U-217 nuclei, only information on the ground state is available. Levels in Bi-217 are known only from isomer decay following fragmentation reaction and those in At-217 and Rn-217 only from the a decay of Fr-221 and Ra-221, respectively. High spin levels in Ra-217 are mainly from 1987SuZY and 2011MuZZ which are a lab report and thesis, respectively. Due to differences between these studies, further experimental study is needed to firmly establish the level scheme.This evaluation was carried out as part of a joint IAEA-ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna and ICTP, Trieste, Aug 22 to Sept 2 2016. The evaluation work was coordinated by E.A. McCutchan (BNL). This work supersedes the previous previous A=217 evaluation (2003Ak06) by Y.A. Akovali.

Measurement of beta decay energies of short-lived neutron rich atomic nuclei in the mass range 101 ≤ A ≤ 106 and A=109

International Nuclear Information System (INIS)

Weikard, H.

1986-01-01

At the mass separator LOHENGRIN of the Laue-Langevin institute in Grenoble for 18 nuclei (Zr, Nb, Mo, Tc, Ru, and Rh nuclides) with masses 101 ≤ A ≤ 106 and A=109 Q β values were determined from measurement of beta decay energies. From the study of the isomerism in 102 Nb resulted that the energetic distance of the two isomers is certainly smaller than 200 keV, that it is probably even smaller than 100 keV. The decay scheme for 102 Nb could be extended by one level which is depopulated by two gamma lines. For the decay of the 109 Ru the approach of a decay scheme is given: Five new levels are proposed. The diagrams of the two-particle separation energies which could be extended in this thesis confirm the continuation of the deformation in the considered region. A deformed subshell at N=62 however cannot yet be clearly detected. (orig./HSI) [de

Decay of mass-separated 187Au (8.4 min) to 187Pt

International Nuclear Information System (INIS)

Gnade, B.E.; Fink, R.W.; Wood, J.L.

1983-01-01

The decay of 187 Au to 187 Pt has been studied with mass-separated sources from the UNISOR facility. Multiscaled spectra of γ-rays, X-rays, and conversion electrons, as well as γγt, Xγt, eγt, and eXt coincidences were obtained. The half-life of the 187 Au ground state was measured to be 8.4 +- 0.3 min. A decay scheme has been constructed incorporating 88% of the decay intensity assigned to 187 Au. The isub(13/2) band in 187 Pt is populated through low-spin band members. The levels at 260 and 288 keV are found to de-excite by EO transitions. From a γ-ray-gated K/β + ratio, the β-decay energy of 8.4 min 187 Au is deduced to be Qsub(EC)=3.90 +- 0.15 MeV. The positive-parity states in 187 Pt are compared with calculations made using the Nilsson model with a triaxial degree of freedom. The possibility that shape coexistence is present at low energy in 187 Pt is discussed. (orig.)

Application of stable adaptive schemes to nuclear reactor systems, (1)

International Nuclear Information System (INIS)

Fukuda, Toshio

1978-01-01

Parameter identification and adaptive control schemes are presented for a point reactor with internal feedbacks which lead to the nonlinearity of the overall system. Both are shown stable with new representation of the system, which corresponds to the nonminimal system representation, in the vein of the Model Reference Adaptive System (MRAS) via the Lyapunov's method. For the sake of the parameter identification, model parameters can be adjusted adaptively as soon as measurements start, while plant parameters can also adaptively be compensated through control input to reduce the output error between the model and the plant for the case of the adaptive control. In the case of the adaptive control, control schemes are presented for two cases, the case of the unknown decay constant of the delayed neutron and the case of the known constant. The adaptive control scheme for the latter case is shown extremely simpler than that for the former. Furthermore, when plant parameters vary slowly with time, computer simulations show that the proposed adaptive control scheme works satisfactorily enough to stabilize an unstable reactor and that it does even in the noise with small variance. (auth.)

Spatial eigensolution analysis of energy-stable flux reconstruction schemes and influence of the numerical flux on accuracy and robustness

Science.gov (United States)

Mengaldo, Gianmarco; De Grazia, Daniele; Moura, Rodrigo C.; Sherwin, Spencer J.

2018-04-01

This study focuses on the dispersion and diffusion characteristics of high-order energy-stable flux reconstruction (ESFR) schemes via the spatial eigensolution analysis framework proposed in [1]. The analysis is performed for five ESFR schemes, where the parameter 'c' dictating the properties of the specific scheme recovered is chosen such that it spans the entire class of ESFR methods, also referred to as VCJH schemes, proposed in [2]. In particular, we used five values of 'c', two that correspond to its lower and upper bounds and the others that identify three schemes that are linked to common high-order methods, namely the ESFR recovering two versions of discontinuous Galerkin methods and one recovering the spectral difference scheme. The performance of each scheme is assessed when using different numerical intercell fluxes (e.g. different levels of upwinding), ranging from "under-" to "over-upwinding". In contrast to the more common temporal analysis, the spatial eigensolution analysis framework adopted here allows one to grasp crucial insights into the diffusion and dispersion properties of FR schemes for problems involving non-periodic boundary conditions, typically found in open-flow problems, including turbulence, unsteady aerodynamics and aeroacoustics.

Compilation of nuclear decay data used for dose calculations. Data for radionuclides not listed in ICRP publication 38

Energy Technology Data Exchange (ETDEWEB)

Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tamura, Tsutomu

1999-07-01

Nuclear decay data used for dose calculations were compiled for 162 nuclides with half-lives greater than or equal to 10 min that are not listed in ICRP Publication 38 (Publ. 38) and their 28 daughter nuclides. Additional 14 nuclides that are considered to be important in fusion reactor facilities were also included. The data were compiled using decay data sets of the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Investigations of the data sets were performed to check their consistency by referring to recent literature and NUBASE, the database for nuclear and decay properties of nuclides, and by using the utility programs of ENSDF. Possible revisions of the data sets were made for their format and syntax errors, level schemes, normalization records, and so on. The revised data sets were processed by EDISTR in order to calculate the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays including annihilation photons, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformations of the radionuclides. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were presented in two types of format; Publ. 38 and NUCDECAY formats. This report provides the decay data in the Publ. 38 format along with decay scheme drawings. The data will be widely used for internal and external dose calculations in radiation protection. (author)

Levels of 250Cf populated in the decay of 250Bk

International Nuclear Information System (INIS)

Uecke, J.W.

1975-06-01

The nuclide 250 Bk undergoes β-decay with a half-life of 3.2 h to 13.1 y 250 Cf. A study is undertaken of the excited states in 250 Cf populated by 250 Bk decay which results from the α-decay of 276d 254 Es. The general features of published level schemes for these nuclei are consistent with predictions of the Nilsson and collective models; however, there remain many undiscovered transitions and ambiguous or uncertain level assignments. In an attempt to confirm predictions of current theoretical models which account for nuclear level assignments in this nucleus, these gamma transitions and their levels have been studied. Twenty-eight new γ-rays were determined. The decay of 250 Bk is investigated primarily by high resolution gamma-ray singles spectrometry and supported in part by two-parameter gamma-gamma coincidence spectrometry. The equipment, comprised of a Ge(HP) and a large volume Ge(Li) detector, a 4096-channel two-parameter analyzer, and a PDP-8/e computer system, permitted significant improvement in sensitivity and accuracy over previous investigations on this nucleus. (11 figures, 2 tables) (U.S.)

Level structures of 131,129Ce observed in beta decay

International Nuclear Information System (INIS)

Gizon, A.; Cata-Danil, G.; Gizon, J.; Nyako, B.M.; Paris, P.; Penev, I.; Plochocki, A.; Ruchowska, E.; Ur, C.A.; Weiss, B.

1996-01-01

The low-lying levels of the odd-mass nuclei 131 Ce and 129 Ce have been investigated by means of the β + /EC decays of 131g+m Pr and 129 Pr, respectively. The Pr nuclei were obtained by bombarding 94,96 Mo targets with a 255 MeV 40 Ca beam. The radioactivities produced in the reactions were transported with a He-jet device and γγt, Xγt, e - γt coincidence measurements were performed. Conversion electrons were measured with a magnetic spectrometer and transition multipolarities were deduced. On-line mass separation was used to select the 129 Pr β-decay. The resulting level schemes of 131,129,127 Ce are discussed in connection with level systematics and calculations performed by using the interacting boson-fermion model (IBFM). (orig.)

Decay out of superdeformed bands in Tb isotopes

International Nuclear Information System (INIS)

Petrache, C.M.; Beck, F.A.; Flibotte, S.; France, G. de; Theisen, C.; Vivien, J.P.

1995-01-01

Excited states in the 150,151,152 Tb isotopes have been investigated using the 130 Te( 27 Al, xn) reaction and the EUROGAM array. The theoretical interpretation of the level schemes has been performed in the framework of the deformed independent particle model. The feeding patterns of the normal-deformed states by the superdeformed bands in 150,151 Tb istopes have also been established. The results indicate that the decay-out mechanism of the bands is not of purely statistical nature, but depends on the configurations of both normal- and superdeformed states. (orig.)

Gamma decay and band structures in 46Ti

International Nuclear Information System (INIS)

Dracoulis, G.D.; Radford, D.C.; Poletti, A.R.

1978-03-01

The states of 46 Ti have been studied using the 43 Ca(α,nγ) reaction. The level and decay scheme of 46 Ti was deduced from γ-γ coincidence, γ-ray energy and intensity measurements. Spins are suggested on the basis of the γ-ray angular distribution, supported by relative excitation functions. The ground state band has been extended to spin 10 + , and about 20 new states are observed. Some of these can be grouped into rotational-like bands based on the 3 - state at 3.059 MeV and other excited states

Study on decay of 118Xe and 119Xe by means of mass-separator on-line with a synchrocyclotron

International Nuclear Information System (INIS)

Berlovich, Eh.E.; Batist, L.Kh.; Blinnikov, Yu.S.

1976-01-01

The decay of sup(118, 119)Xe isotopes has been investigated. An experimental device involving a mass-separator operating in line with a synchrocyclotron is briefly outlined. The elements to be investigated were isolated from a proton-irradiated target by the 'on-beam-chemistry' methods and transferred into the mass-separator ion source. The Xe separated ions are transported to detectors in an experimental ha ll. The energies and relative γ ray intensities of 118 Xe → 118 J and of 119 Xe → 119 J decays ar presented. The error of the γ ray energy determination does not exceed 0.6 keV. Obtained are the periods of half-life: for 118 Xe - (3.8+-0.9) min, for 119 Xe - (5.8+-0.3) min. The decay scheme for 119 Xe is made up. The scheme of 119 Xe levels is well inscribed into the general systematics of the J odd isotope levels. On the basis of obtained and known data the spin values are described to the 119 J levels

Two-body decays of gluino at full one-loop level in the quark-flavour violating MSSM.

Science.gov (United States)

Eberl, Helmut; Ginina, Elena; Hidaka, Keisho

2017-01-01

We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalisation is done in the [Formula: see text] scheme. The gluon and photon radiations are included by adding the corresponding three-body decay widths. We discuss the dependence of the gluino decay widths on the QFV parameters. The main dependence stems from the [Formula: see text]-[Formula: see text] mixing in the decays to up-type squarks, and from the [Formula: see text]-[Formula: see text] mixing in the decays to down-type squarks due to the strong constraints from B-physics on the other quark-flavour-mixing parameters. The full one-loop corrections to the gluino decay widths are mostly negative and of the order of about -10%. The QFV part stays small in the total width but can vary up to -8% for the decay width into the lightest [Formula: see text] squark. For the corresponding branching ratio the effect is somehow washed out by at least a factor of two. The electroweak corrections can be as large as 35% of the SUSY QCD corrections.

A gradient stable scheme for a phase field model for the moving contact line problem

KAUST Repository

Gao, Min

2012-02-01

In this paper, an efficient numerical scheme is designed for a phase field model for the moving contact line problem, which consists of a coupled system of the Cahn-Hilliard and Navier-Stokes equations with the generalized Navier boundary condition [1,2,4]. The nonlinear version of the scheme is semi-implicit in time and is based on a convex splitting of the Cahn-Hilliard free energy (including the boundary energy) together with a projection method for the Navier-Stokes equations. We show, under certain conditions, the scheme has the total energy decaying property and is unconditionally stable. The linearized scheme is easy to implement and introduces only mild CFL time constraint. Numerical tests are carried out to verify the accuracy and stability of the scheme. The behavior of the solution near the contact line is examined. It is verified that, when the interface intersects with the boundary, the consistent splitting scheme [21,22] for the Navier Stokes equations has the better accuracy for pressure. © 2011 Elsevier Inc.

Off-shell s→d transitions i K-decays

International Nuclear Information System (INIS)

Eeg, J.O.; Picek, I.

1992-07-01

The authors consider contributions to decays of K-mesons from effective lagrangians involving (iγ·D-m q ), where D μ is the covariant derivative and m q is a relevant quark mass. For this purpose an effective low-energy QCD is used, where the quarks are coupled to the pseudoscalar mesons π, K, η. These couplings are due to their Goldstone character and reflect chiral-symmetry breaking. Within this scheme it is shown explicitly that for the decays K→ππ and K→γγ, the physical effects of operators involving (iγ·D-m q ) are not zero, contrary to current statements. To be more specific, one obtains a zero effect only in the limit when the quark-meson interactions are switched off, that is for f π →∞. Numerically, one finds weak impact on the CP-conserving K→ππ amplitude, while the impact of K→γγ is substantial in the CP-violating case. 17 refs., 4 figs

Velocity and stress autocorrelation decay in isothermal dissipative particle dynamics

Science.gov (United States)

Chaudhri, Anuj; Lukes, Jennifer R.

2010-02-01

The velocity and stress autocorrelation decay in a dissipative particle dynamics ideal fluid model is analyzed in this paper. The autocorrelation functions are calculated at three different friction parameters and three different time steps using the well-known Groot/Warren algorithm and newer algorithms including self-consistent leap-frog, self-consistent velocity Verlet and Shardlow first and second order integrators. At low friction values, the velocity autocorrelation function decays exponentially at short times, shows slower-than exponential decay at intermediate times, and approaches zero at long times for all five integrators. As friction value increases, the deviation from exponential behavior occurs earlier and is more pronounced. At small time steps, all the integrators give identical decay profiles. As time step increases, there are qualitative and quantitative differences between the integrators. The stress correlation behavior is markedly different for the algorithms. The self-consistent velocity Verlet and the Shardlow algorithms show very similar stress autocorrelation decay with change in friction parameter, whereas the Groot/Warren and leap-frog schemes show variations at higher friction factors. Diffusion coefficients and shear viscosities are calculated using Green-Kubo integration of the velocity and stress autocorrelation functions. The diffusion coefficients match well-known theoretical results at low friction limits. Although the stress autocorrelation function is different for each integrator, fluctuates rapidly, and gives poor statistics for most of the cases, the calculated shear viscosities still fall within range of theoretical predictions and nonequilibrium studies.

Alpha-gamma decay studies of 253No and its daughter products 253Md, 249Fm

International Nuclear Information System (INIS)

Hessberger, F.P.; Antalic, S.; Kalaninova, Z.; Saro, S.; Venhart, M.; Ackermann, D.; Heinz, S.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Lommel, B.; Mann, R.; Sulignano, B.; Hofmann, S.; Streicher, B.; Leino, M.; Nishio, K.

2012-01-01

Nuclear structure and decay of the isotope 253 No and its decay products 249 Fm and 253 Md were investigated by means of α - γ spectroscopy. Besides the established strong γ transitions from the 9/2 - [734] Nilsson level in 249 Fm, populated predominantly by the α decay of 253 No, into the ground-state (gs) rotational band, a couple of weaker γ lines (58.3, 129.2, 209.3 and 669.5keV) were observed and placed into the 249 Fm level scheme. The transition from the 7/2 - level in 249 Es, populated by the α decay of 253 Md, into the 9/2 + member of the gs rotational band, so far established for other odd-mass Es isotopes, was observed clearly. GEANT4 simulations were performed to investigate the influence of energy summing between α particles and conversion electrons (CE) on the shape of the α spectra at different implantation energies, leading to evidence for a weak α decay branch of 253 No into the gs of 249 Fm or the ground-state rotational band, respectively. (orig.)

Consistent treatment of ground deposition together with species growth and decay during atmospheric transport

International Nuclear Information System (INIS)

Murphy, B.D.; Nelson, C.B.; Ohr, S.Y.

1981-01-01

We discuss the adaptation of a trajectory model to an initial pollutant species and a series of successor species at mesoscale distances. The effect of source height is discussed since it is important in determining close-in ground level concentration, which influences plume depletion due to dry deposition. A scheme is outlined which handles deposition and species decay in a consistent manner and which does so for an arbitrary number of successor pollutant species. This scheme is discussed in terms of a Lagrangian trajectory model which accounts for initial source height and which calculates ground-level concentrations out to mesoscale distances

Extension of loop quantum gravity to f(R) theories.

Science.gov (United States)

Zhang, Xiangdong; Ma, Yongge

2011-04-29

The four-dimensional metric f(R) theories of gravity are cast into connection-dynamical formalism with real su(2) connections as configuration variables. Through this formalism, the classical metric f(R) theories are quantized by extending the loop quantization scheme of general relativity. Our results imply that the nonperturbative quantization procedure of loop quantum gravity is valid not only for general relativity but also for a rather general class of four-dimensional metric theories of gravity.

Decay rate of reindeer pellet-groups

Directory of Open Access Journals (Sweden)

Anna Skarin

2008-06-01

Full Text Available Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus. During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus tidigare. I omr

Improving perfusion quantification in arterial spin labeling for delayed arrival times by using optimized acquisition schemes

International Nuclear Information System (INIS)

Kramme, Johanna; Diehl, Volker; Madai, Vince I.; Sobesky, Jan; Guenther, Matthias

2015-01-01

The improvement in Arterial Spin Labeling (ASL) perfusion quantification, especially for delayed bolus arrival times (BAT), with an acquisition redistribution scheme mitigating the T1 decay of the label in multi-TI ASL measurements is investigated. A multi inflow time (TI) 3D-GRASE sequence is presented which adapts the distribution of acquisitions accordingly, by keeping the scan time constant. The MR sequence increases the number of averages at long TIs and decreases their number at short TIs and thus compensating the T1 decay of the label. The improvement of perfusion quantification is evaluated in simulations as well as in-vivo in healthy volunteers and patients with prolonged BATs due to age or steno-occlusive disease. The improvement in perfusion quantification depends on BAT. At healthy BATs the differences are small, but become larger for longer BATs typically found in certain diseases. The relative error of perfusion is improved up to 30% at BATs > 1500 ms in comparison to the standard acquisition scheme. This adapted acquisition scheme improves the perfusion measurement in comparison to standard multi-TI ASL implementations. It provides relevant benefit in clinical conditions that cause prolonged BATs and is therefore of high clinical relevance for neuroimaging of steno-occlusive diseases.

Neutron decay, semileptonic hyperon decay and the Cabibbo model

International Nuclear Information System (INIS)

Siebert, H.W.

1989-01-01

The decay rates and formfactor ratios of neutron decay and semileptonic hyperon decays are compared in the framework of the Cabibbo model. The results indicate SU(3) symmetry breaking. The Kobayashi-Maskawa matrix element V us determined from these decays is in good agreement with the value determined from K→πeν decays, and with unitarity of the KM-matrix. (orig.)

Comprehending isospin breaking effects of X (3872 ) in a Friedrichs-model-like scheme

Science.gov (United States)

Zhou, Zhi-Yong; Xiao, Zhiguang

2018-02-01

Recently, we have shown that the X (3872 ) state can be naturally generated as a bound state by incorporating the hadron interactions into the Godfrey-Isgur quark model using a Friedrichs-like model combined with the quark pair creation model, in which the wave function for the X (3872 ) as a combination of the bare c c ¯ state and the continuum states can also be obtained. Under this scheme, we now investigate the isospin-breaking effect of X (3872 ) in its decays to J /ψ π+π- and J /ψ π+π-π0. By coupling its dominant continuum parts to J /ψ ρ and J /ψ ω through the quark rearrangement process, one could obtain the reasonable ratio of B (X (3872 )→J /ψ π+π-π0)/B (X (3872 )→J /ψ π+π-)≃ (0.58 - 0.92 ) . It is also shown that the D ¯D* invariant mass distributions in the B →D ¯D*K decays could be understood qualitatively at the same time. This scheme may provide more insight into the enigmatic nature of the X (3872 ) state.

Additive operator-difference schemes splitting schemes

CERN Document Server

Vabishchevich, Petr N

2013-01-01

Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

Retrieval program system of Chinese Evaluated (frequently useful) Nuclear Decay Database

International Nuclear Information System (INIS)

Huang Xiaolong; Zhou Chunmei

1995-01-01

The Chinese Evaluated (frequently useful) Nuclear Decay Database has been set up in MICRO-VAX-11 computer at Chinese Nuclear Data Center (CNDC). For users' convenience, the retrieval program system of the database is written. Retrieval can be carried out for one nucleus or multi-nucleus. The retrieved results can be displayed on terminal screen or output to M3081 printer and laser printer in ENSDF format, table report or scheme diagrams

A study of the Roper resonance as a hybrid state from J/ψ decays

International Nuclear Information System (INIS)

Ping, R.G.; Chiang, H.C.; Zou, B.S.

2004-01-01

The structure of the Roper resonance as a hybrid baryon is investigated through studying the transitional amplitudes in J/ψ->p-bar N*, N-bar *N* decays. We begin with perturbative QCD to describe the dynamical process for the J/ψ->3q-bar +3q decay to the lowest order of αs, and by extending the modified quark creation model to the J/ψ energy region to describe the J/ψ->3q-bar +3q+g process. The nonperturbative effects are incorporated by a simple quark model of baryons to evaluate the angular distribution parameters and decay widths for the processes J/ψ->p-bar N*, N-bar *N*. From fitting the decay width of J/ψ->γpp-bar to the experimental data, we extract the quark-pair creation strength gI=15.40-bar GeV. Our numerical results for J/ψ->p-bar N*, N-bar *N* decays show that the branching ratios for these decays are quite different if the Roper resonance is assumed to be a common 3q state or a pure hybrid state. For testing its mixing properties, we present a scheme to construct the Roper wave function by mixing vertical bar qqqg> state with a normal vertical bar qqq,2s> state. Under this picture, the ratios of the decay widths to that of the J/ψ->pp-bar decay are re-evaluated versus the mixing parameter. A test of the hybrid nature of the Roper resonance in J/ψ decays is discussed

Alpha-gamma decay studies of 255No

International Nuclear Information System (INIS)

Hessberger, F.P.; Ackermann, D.; Kindler, B.; Kojouharov, I.; Kuusiniemi, P.; Lommel, B.; Mann, R.; Hofmann, S.; Antalic, S.; Saro, S.; Streicher, B.; Venhart, M.; Leino, M.; Nishio, K.; Popeko, A.G.; Yeremin, A.V.; Sulignano, B.

2006-01-01

The decay of 255 No was investigated by means of α-γ spectroscopy. The isotope was produced in the reactions 208 Pb( 48 Ca,n) 255 No, 209 Bi( 48 Ca,2n) 255 Lr EC → 255 No, and 238 U( 22 Ne,5n) 255 No. Levels of the daughter nucleus 251 Fm were assigned by α-γ coincidence measurements and on the basis of systematics. Level energies were determined precisely using measured γ-rays. The results are compared with the known level schemes of the lighter N=151 isotones 247 Cm and 249 Cf as well as with data for 253 No. (orig.)

Dipion decay modes of the UPSILON family from a universal epsilon coupling

International Nuclear Information System (INIS)

Coffou, E.; Martinis, M.; Mikuta-Martinis, V.

1986-01-01

In the framework of a universal-epsilon-coupling scheme we obtain predictions for the decay rates of UPSILON'→UPSILONππ, UPSILON''→UPSILONππ, and UPSILON''→UPSILON'ππ in agreement with CLEO and CUSB measurements. We also predict the shape of the dipion mass distribution for these transitions. The shape predicted for UPSILON'→UPSILONππ is found to be in excellent agreement with experiment

Higgs boson decay into b-quarks at NNLO accuracy

Science.gov (United States)

Del Duca, Vittorio; Duhr, Claude; Somogyi, Gábor; Tramontano, Francesco; Trócsányi, Zoltán

2015-04-01

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

Higgs boson decay into b-quarks at NNLO accuracy

CERN Document Server

Del Duca, Vittorio; Somogyi, Gábor; Tramontano, Francesco; Trócsányi, Zoltán

2015-01-01

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

Tentative of observation of the ρ+ → π+ + γ decay mode

International Nuclear Information System (INIS)

Daudin, A.; Jabiol, M.A.; Kochowski, C.; Lewin, C.; Rogozinski, A.

1964-01-01

One of the purposes of the 1.6 GeV/c π + p experiment, carried out in the 50 cm Saclay hydrogen bubble chamber, was to observe the ρ + → π + γ radiative decay mode in π + p → π + p γ interactions. A 6 mm thick lead plate, set at the outgoing part of the chamber, was used to convert γ into e + e - . Among the γ observed arising directly from the investigated interactions, no event originates from a π + γ compound in the region of ρ + . This gives an upper limit of 2 per cent for the branching ratio (ρ + → π + γ) / (ρ + → π + γ + ρ + → π + π 0 ). (authors) [fr

Weak decays of doubly heavy baryons. Multi-body decay channels

Energy Technology Data Exchange (ETDEWEB)

Shi, Yu-Ji; Wang, Wei; Xing, Ye; Xu, Ji [Shanghai Jiao Tong University, INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology, MOE Key Laboratory for Particle Physics, Astrophysics and Cosmology, School of Physics and Astronomy, Shanghai (China)

2018-01-15

The newly-discovered Ξ{sub cc}{sup ++} decays into the Λ{sub c}{sup +}K{sup -}π{sup +}π{sup +}, but the experimental data has indicated that this decay is not saturated by any two-body intermediate state. In this work, we analyze the multi-body weak decays of doubly heavy baryons Ξ{sub cc}, Ω{sub cc}, Ξ{sub bc}, Ω{sub bc}, Ξ{sub bb} and Ω{sub bb}, in particular the three-body nonleptonic decays and four-body semileptonic decays. We classify various decay modes according to the quark-level transitions and present an estimate of the typical branching fractions for a few golden decay channels. Decay amplitudes are then parametrized in terms of a few SU(3) irreducible amplitudes. With these amplitudes, we find a number of relations for decay widths, which can be examined in future. (orig.)

Chiral symmetry and eta, eta' → 3π decays. Grand unified theories

International Nuclear Information System (INIS)

Roiesnel, C.

1982-11-01

Two different topics related to symmetry breaking are discussed. First the eta, eta' → 3π decays are presented. The amplitudes eta, eta' → 3π are calculated with the square root threshold singularity induced by the strong pion-pion final state interaction properly taken into account. It is shown that the eta' → 3π decay rate depends sensitively upon an improved treatment of the pseudoscalar nonet mass matrix. Then symmetry-breaking effects in grand unified theories are discussed. The threshold effects in a spontaneously broken gauge theory are studied. In particular a computation of the symmetry-breaking effects in the SU(5) grand unified theory including those of the breaking of SU(2)xU(1) is presented. As an application a precise value of the superheavy gauge boson mass Mx is given. It is possible in SU(5) to define a natural effective weak angle theta w(μ) for any scale μ, below as well as above Mw, and the predicted curve for sin 2 theta w(μ) is given [fr

Is nuclear structure relevant to non-mesonic hyper-nuclear weak decay?

International Nuclear Information System (INIS)

Wu, H.C.; Ponce, W.A.

2001-01-01

Full text: The focus of existing studies of the non-mesonic hypernuclear weak decay has been on the two-body process ΛN → NN, whereas the investigation on effects of nuclear structure is relatively rare. Some authors even assumed that the nuclear structure is irrelevant to the non mesonic hypernuclear weak decay. In this work we try to reveal the importance of nuclear structure in non mesonic weak decay of the Λ - hypernuclei through examining the relevance of many-body properties as well as the single particle properties of different nuclear models. For hypernucleus 12 Λ C, a comparison between the L-S coupling (realized by the symmetry model SU(4) x SU(3) and the j-j coupling (realized by the single particle shell model) gives an estimate of the range of nuclear structure effects. It has been found that while the total decay rate is almost independent of coupling schemes, the ratio Γn/Γp has a difference of around 30% between the two limits of many-body wave functions. There also exists a strong dependence of the total decay rate and the ratio Γn/Γp on the single particle properties of shell model, such as the binding energy of nucleon and the parameters of harmonic oscillator orbits, etc. Therefore, one may conclude that the nuclear structure is relevant to the non-mesonic hypernuclear weak decay. With the mechanism of ΛN → NN transition being restricted to one pion exchange (OPE) only, the consequences of possible contribution from the ΔI = 3/2 channel is investigated in a phenomenological manner. It has been shown that a mixing of ΔI = 3/2 channel will change the total decay rate as well as the ratio Γn/Γp considerably. (Author)

Weak decays

International Nuclear Information System (INIS)

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

Constraining f(R gravity in solar system, cosmology and binary pulsar systems

Directory of Open Access Journals (Sweden)

Tan Liu

2018-02-01

Full Text Available The f(R gravity can be cast into the form of a scalar–tensor theory, and scalar degree of freedom can be suppressed in high-density regions by the chameleon mechanism. In this article, for the general f(R gravity, using a scalar–tensor representation with the chameleon mechanism, we calculate the parametrized post-Newtonian parameters γ and β, the effective gravitational constant Geff, and the effective cosmological constant Λeff. In addition, for the general f(R gravity, we also calculate the rate of orbital period decay of the binary system due to gravitational radiation. Then we apply these results to specific f(R models (Hu–Sawicki model, Tsujikawa model and Starobinsky model and derive the constraints on the model parameters by combining the observations in solar system, cosmological scales and the binary systems.

Nonlinear evolution of f(R) cosmologies. I. Methodology

International Nuclear Information System (INIS)

Oyaizu, Hiroaki

2008-01-01

We introduce the method and the implementation of a cosmological simulation of a class of metric-variation f(R) models that accelerate the cosmological expansion without a cosmological constant and evade solar-system bounds of small-field deviations to general relativity. Such simulations are shown to reduce to solving a nonlinear Poisson equation for the scalar degree of freedom introduced by the f(R) modifications. We detail the method to efficiently solve the nonlinear Poisson equation by using a Newton-Gauss-Seidel relaxation scheme coupled with the multigrid method to accelerate the convergence. The simulations are shown to satisfy tests comparing the simulated outcome to analytical solutions for simple situations, and the dynamics of the simulations are tested with orbital and Zeldovich collapse tests. Finally, we present several static and dynamical simulations using realistic cosmological parameters to highlight the differences between standard physics and f(R) physics. In general, we find that the f(R) modifications result in stronger gravitational attraction that enhances the dark matter power spectrum by ∼20% for large but observationally allowed f(R) modifications. A more detailed study of the nonlinear f(R) effects on the power spectrum are presented in a companion paper.

Nuclear decay data files of the Dosimetry Research Group

International Nuclear Information System (INIS)

Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

1993-12-01

This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ''MIRD: Radionuclide Data and Decay Schemes.'' The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory

Multilocus sequence typing scheme for the Mycobacterium abscessus complex.

Science.gov (United States)

Macheras, Edouard; Konjek, Julie; Roux, Anne-Laure; Thiberge, Jean-Michel; Bastian, Sylvaine; Leão, Sylvia Cardoso; Palaci, Moises; Sivadon-Tardy, Valérie; Gutierrez, Cristina; Richter, Elvira; Rüsch-Gerdes, Sabine; Pfyffer, Gaby E; Bodmer, Thomas; Jarlier, Vincent; Cambau, Emmanuelle; Brisse, Sylvain; Caro, Valérie; Rastogi, Nalin; Gaillard, Jean-Louis; Heym, Beate

2014-01-01

We developed a multilocus sequence typing (MLST) scheme for Mycobacterium abscessus sensu lato, based on the partial sequencing of seven housekeeping genes: argH, cya, glpK, gnd, murC, pta and purH. This scheme was used to characterize a collection of 227 isolates recovered between 1994 and 2010 in France, Germany, Switzerland and Brazil. We identified 100 different sequence types (STs), which were distributed into three groups on the tree obtained by concatenating the sequences of the seven housekeeping gene fragments (3576bp): the M. abscessus sensu stricto group (44 STs), the "M. massiliense" group (31 STs) and the "M. bolletii" group (25 STs). SplitTree analysis showed a degree of intergroup lateral transfers. There was also evidence of lateral transfer events involving rpoB. The most prevalent STs in our collection were ST1 (CC5; 20 isolates) and ST23 (CC3; 31 isolates). Both STs were found in Europe and Brazil, and the latter was implicated in a large post-surgical procedure outbreak in Brazil. Respiratory isolates from patients with cystic fibrosis belonged to a large variety of STs; however, ST2 was predominant in this group of patients. Our MLST scheme, publicly available at www.pasteur.fr/mlst, offers investigators a valuable typing tool for M. abscessus sensu lato in future epidemiological studies throughout the world. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Measurements of hyperon semileptonic decays at the CERN Super Proton Synchrotron

International Nuclear Information System (INIS)

Bourquin, M.; Chatelus, Y.; Brown, R.M.

1983-06-01

Results on five different hyperon semileptonic decays from the WA2 experiment, performed in the CERN SPS charged hyperon beam, have been analysed within the framework of the Cabibbo model. For the first time, the inconsistencies, which inevitably occur when the results from different experiments are combined, have been avoided in these comprehensive fits to high statistics data from a single hyperon decay experiment. Excellent agreement with the basic Cabibbo model has been obtained using the WA2 data either alone or together with neutron lifetime measurements. These results contrast strongly with other recent Cabibbo analyses which have indicated the presence of SU(3) breaking effects. Using additional information on ft values for superallowed nuclear Fermi transitions, an upper limit on the mixing parameter sintheta 3 in the Kobayashi-Maskawa six quark scheme has been obtained. (author)

Investigation of excited states and isomer decay in doubly odd 208Fr

International Nuclear Information System (INIS)

Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R.K.; Gehlot, J.; Jnaneswari, G.; Muralithar, S.; Singh, R.P.; Mukherjee, B.; Mukherjee, G.

2008-01-01

A systematic study of the 212 Fr nuclei will reveal many other interesting features like the interplay of the single particle and the collective degrees of freedom in generating high angular momenta, collectively, if any, in these nuclei at higher spins, and possibly many more

Levels and transitions in 160Dy following the decay of 160Tb

International Nuclear Information System (INIS)

Noordin bin Ibrahim; Stewart, N.M.

1989-01-01

The level scheme of 160 Dy has been established from γ-γ coincidence measurement following the β-decay of 160 Tb. Ge(Li) detectors were coupled to a Dual Parameter Spectrometer for data collection. A total of fifteen new gamma transitions were observed. Two energy levels at 1285 and 1288 keV were confirmed while four levels at 1349, 1670, 1694 and 1804 keV were found to be populated for the first time from β-decay of 160 Tb: Three levels at 1230, 1338 and 1507 keV are newly suggested. Relative intensities for the transitions and branching ratios of the energy levels were determined. Comparisons are made with theoretical predictions of IBA calculations, two considerations were taken: normal shell closure (Z 50/82) and subshell closure (Z = 64). (author)

Godunov-type schemes for hydrodynamic and magnetohydrodynamic modeling

International Nuclear Information System (INIS)

Vides-Higueros, Jeaniffer

2014-01-01

The main objective of this thesis concerns the study, design and numerical implementation of finite volume schemes based on the so-Called Godunov-Type solvers for hyperbolic systems of nonlinear conservation laws, with special attention given to the Euler equations and ideal MHD equations. First, we derive a simple and genuinely two-Dimensional Riemann solver for general conservation laws that can be regarded as an actual 2D generalization of the HLL approach, relying heavily on the consistency with the integral formulation and on the proper use of Rankine-Hugoniot relations to yield expressions that are simple enough to be applied in the structured and unstructured contexts. Then, a comparison between two methods aiming to numerically maintain the divergence constraint of the magnetic field for the ideal MHD equations is performed and we show how the 2D Riemann solver can be employed to obtain robust divergence-Free simulations. Next, we derive a relaxation scheme that incorporates gravity source terms derived from a potential into the hydrodynamic equations, an important problem in astrophysics, and finally, we review the design of finite volume approximations in curvilinear coordinates, providing a fresher view on an alternative discretization approach. Throughout this thesis, numerous numerical results are shown. (author) [fr

Higgs boson decay into b-quarks at NNLO accuracy

Energy Technology Data Exchange (ETDEWEB)

Duca, Vittorio Del [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati,Via E. Fermi 40, I-00044 Frascati (Italy); Duhr, Claude [PH Department, TH Unit, CERN,CH-1211 Geneva 23 (Switzerland); Center for Cosmology, Particle Physics and Phenomenology (CP3),Université Catholique de Louvain, Chemin du Cyclotron 2,B-1348 Louvain-La-Neuve (Belgium); Somogyi, Gábor [University of Debrecen and MTA-DE Particle Physics Research Group,H-4010 Debrecen, PO Box 105 (Hungary); Tramontano, Francesco [Dipartimento di Fisica, Università degli studi di Napoli andINFN - Sezione di Napoli, 80125 Napoli (Italy); Trócsányi, Zoltán [University of Debrecen and MTA-DE Particle Physics Research Group,H-4010 Debrecen, PO Box 105 (Hungary)

2015-04-08

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

Study of neutron rich nuclei by delayed neutron decay using the Tonnerre multidetector; Etude de la decroissance par neutrons retardes de noyaux legers riches en neutrons avec le multidetecteur tonnerre

Energy Technology Data Exchange (ETDEWEB)

Timis, C.N

2001-07-01

A new detection array for beta delayed neutrons was built. It includes up to 32 plastic scintillation counters 180 cm long located at 120 cm from the target. Neutron energy spectra are measured by time-of-flight in the 300 keV-15 MeV range with good energy resolution. The device was tested with several known nuclei. Its performances are discussed in comparison with Monte Carlo simulations. They very high overall detection efficiency on the TONNERRE array made it possible to study one and two neutron emission of {sup 11}Li. A complete decay scheme was obtained. The {sup 33}Mg and {sup 35}Al beta decays were investigated for the first time by neutron and gamma spectroscopy. Complete decay schemes were established and compared to large scale shell-model calculations. (authors)

Study of the Riemann problem and construction of multidimensional Godunov-type schemes for two-phase flow models

International Nuclear Information System (INIS)

Toumi, I.

1990-04-01

This thesis is devoted to the study of the Riemann problem and the construction of Godunov type numerical schemes for one or two dimensional two-phase flow models. In the first part, we study the Riemann problem for the well-known Drift-Flux, model which has been widely used for the analysis of thermal hydraulics transients. Then we use this study to construct approximate Riemann solvers and we describe the corresponding Godunov type schemes for simplified equation of state. For computation of complex two-phase flows, a weak formulation of Roe's approximate Riemann solver, which gives a method to construct a Roe-averaged jacobian matrix with a general equation of state, is proposed. For two-dimensional flows, the developed methods are based upon an approximate solver for a two-dimensional Riemann problem, according to Harten-Lax-Van Leer principles. The numerical results for standard test problems show the good behaviour of these numerical schemes for a wide range of flow conditions [fr

Efficient full decay inversion of MRS data with a stretched-exponential approximation of the ? distribution

Science.gov (United States)

Behroozmand, Ahmad A.; Auken, Esben; Fiandaca, Gianluca; Christiansen, Anders Vest; Christensen, Niels B.

2012-08-01

We present a new, efficient and accurate forward modelling and inversion scheme for magnetic resonance sounding (MRS) data. MRS, also called surface-nuclear magnetic resonance (surface-NMR), is the only non-invasive geophysical technique that directly detects free water in the subsurface. Based on the physical principle of NMR, protons of the water molecules in the subsurface are excited at a specific frequency, and the superposition of signals from all protons within the excited earth volume is measured to estimate the subsurface water content and other hydrological parameters. In this paper, a new inversion scheme is presented in which the entire data set is used, and multi-exponential behaviour of the NMR signal is approximated by the simple stretched-exponential approach. Compared to the mono-exponential interpretation of the decaying NMR signal, we introduce a single extra parameter, the stretching exponent, which helps describe the porosity in terms of a single relaxation time parameter, and helps to determine correct initial amplitude and relaxation time of the signal. Moreover, compared to a multi-exponential interpretation of the MRS data, the decay behaviour is approximated with considerably fewer parameters. The forward response is calculated in an efficient numerical manner in terms of magnetic field calculation, discretization and integration schemes, which allows fast computation while maintaining accuracy. A piecewise linear transmitter loop is considered for electromagnetic modelling of conductivities in the layered half-space providing electromagnetic modelling of arbitrary loop shapes. The decaying signal is integrated over time windows, called gates, which increases the signal-to-noise ratio, particularly at late times, and the data vector is described with a minimum number of samples, that is, gates. The accuracy of the forward response is investigated by comparing a MRS forward response with responses from three other approaches outlining

Classification of decays involving variable decay chains with convolutional architectures

CERN Multimedia

CERN. Geneva

2018-01-01

Vidyo contribution We present a technique to perform classification of decays that exhibit decay chains involving a variable number of particles, which include a broad class of $B$ meson decays sensitive to new physics. The utility of such decays as a probe of the Standard Model is dependent upon accurate determination of the decay rate, which is challenged by the combinatorial background arising in high-multiplicity decay modes. In our model, each particle in the decay event is represented as a fixed-dimensional vector of feature attributes, forming an $n \\times k$ representation of the event, where $n$ is the number of particles in the event and $k$ is the dimensionality of the feature vector. A convolutional architecture is used to capture dependencies between the embedded particle representations and perform the final classification. The proposed model performs outperforms standard machine learning approaches based on Monte Carlo studies across a range of variable final-state decays with the Belle II det...

Simulation of decay processes and radiation transport times in radioactivity measurements

Energy Technology Data Exchange (ETDEWEB)

García-Toraño, E., E-mail: e.garciatorano@ciemat.es [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Peyres, V. [Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Bé, M.-M.; Dulieu, C.; Lépy, M.-C. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), Bldg 602, PC111, 91191 Gif-sur-Yvette Cedex (France); Salvat, F. [Facultat de Física (FQA and ICC), Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)

2017-04-01

The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

EC/β+ decay of 161Er

International Nuclear Information System (INIS)

Kalinnikov, V.G.; Ibraheem, Y.S.; Stegailov, V.I.

2004-01-01

Full text: The study of odd-proton nuclei in rare-earth region has been performed to get more information on the nuclear structure of these nuclei. In the framework of a program at the ISOL complex of YASNAPP-2 at JINR to study the decay of odd-nuclei, 161 Er has been investigated. The experiments have been focused on the 161 Ho level scheme populated in the EC/β + decay of 161 Er for which a few results have been previously reported [1,2]. Spectra of single γ-ray, γ-γ coincidence and internal conversion electrons were measured. There are appreciable disagreements between results of some γ-ray intensities obtained by us and in [2]. The greatest difference was for relative γ-ray intensity of the 11.28 keV, which has reported value I γ ∼ 10 (I γ 211 =1000) in [2], but this leads to an overpopulation of the 211 keV level by 14% of the decay [3]. The relative intensities of transitions with Eγ γ211 =1000). Inaccuracy of Iγ in [2] is probably due to a sudden change in the efficiency curve of their Ge(Li) detector in the low energy region while our HPGe detector feature a much smoother variation in the efficiency curve in this γ-ray energy region. Besides, the levels earlier introduced by us in [4], three new levels in 161 Ho were proposed from γ-γ coincidences at energies 693.2 keV, 859.6 keV, and 957.97 keV. Spins, parities and Nilsson quantum characteristics of some 161 Ho levels were established

Gaseous release of radioactive iodine from decaying plants. I. Release following foliar and root uptake

International Nuclear Information System (INIS)

Saas, Arsene; Grauby, Andre

1975-12-01

Iodine uptake by plants is a significant link in the contamination of the food chain. Long half-live iodine was studied considering foliar and root uptake, loss by rain scavenging, residue decay or outgassing in order to assess two aspects of the problem: the importance of outgassing and the effect of the route of transfer on iodine losses. It appeared that iodine release was a function of the vegetal type, there were differences according to the pattern of absorption (via leaf or root) and the processes of iodine release were usually related to biochemical mechanisms [fr

Branching ratios and CP asymmetries in the decay B → VV

International Nuclear Information System (INIS)

Kramer, G.; Palmer, W.F.

1991-06-01

We carry out a systematic study of branching ratios, angular correlations, and CP asymmetries in the decay of neutral and charged B mesons to final states consisting of two vector mesons. The renormalization group improved effective Hamiltonian is evaluated in the vacuum insertion (factorization) approximation. OZI suppressed and annihilation terms are neglected. Current matrix elements are evaluated using the wave functions of Bauer, Stech and Wirbel. Branching ratios and angular correlations among subsequent decays of the vector mesons are calculated for 34 channels and a comparison is made with the data. As a first approximation, the calculational scheme provides a useful framework with which to organize the data. Interesting direct CP asymmetries are particularly evident in K*ω and K*ρ final states, where branching ratios are moderate. They are excellent probes of penguin term influence on decay amplitudes. Even larger direct asymmetries are present in ωρ and ρρ final states where, however, branching ratios are low and results are very model dependent. We show how B 0 -B 0 mixing phases are influenced by phases in the direct amplitudes. The effect is particularly strong for K* 0 D* 0 final states. (orig.)

Proton decay theory

International Nuclear Information System (INIS)

Marciano, W.J.

1983-01-01

Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay

Generic calculation of two-body partial decay widths at the full one-loop level

Science.gov (United States)

Goodsell, Mark D.; Liebler, Stefan; Staub, Florian

2017-11-01

We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson as well as scalar decays into two fermions, two gauge bosons, two scalars or a scalar and a gauge boson. We present the relevant generic expressions for virtual and real corrections. Whereas wave-function corrections are determined from on-shell conditions, the parameters of the underlying model are by default renormalised in a \\overline{ {DR}} (or \\overline{ {MS}}) scheme. However, the user can also define model-specific counter-terms. As an example we discuss the renormalisation of the electric charge in the Thomson limit for top-quark decays in the standard model. One-loop-induced decays are also supported. The framework additionally allows the addition of mass and mixing corrections induced at higher orders for the involved external states. We explain our procedure to cancel infrared divergences for such cases, which is achieved through an infrared counter-term taking into account corrected Goldstone boson vertices. We compare our results for sfermion, gluino and Higgs decays in the minimal supersymmetric standard model (MSSM) against the public codes SFOLD, FVSFOLD and HFOLD and explain observed differences. Radiatively induced gluino and neutralino decays are compared against the original implementation in SPheno in the MSSM. We exactly reproduce the results of the code CNNDecays for decays of neutralinos and charginos in R-parity violating models. The new version SARAH 4.11.0 by default includes the calculation of two-body decay widths at the full one-loop level. Current limitations for certain model classes are described.

Generic calculation of two-body partial decay widths at the full one-loop level

Energy Technology Data Exchange (ETDEWEB)

Goodsell, Mark D. [UPMC Univ. Paris 06 (France); Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Sorbonne Univ., Paris (France); Liebler, Stefan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Staub, Florian [Karlsruhe Institute for Technology, Karlsruhe (Germany). Inst. for Theoretical Physics; Karlsruhe Institute for Technology, Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Physics

2017-04-15

We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson as well as scalar decays into two fermions, two gauge bosons, two scalars or a scalar and a gauge boson. We present the relevant generic expressions for virtual and real corrections. Whereas wavefunction corrections are determined from on-shell conditions, the parameters of the underlying model are by default renormalised in a DR (or MS) scheme. However, the user can also define model-specific counter-terms. As an example we discuss the renormalisation of the electric charge in the Thomson limit for top-quark decays in the standard model. One-loop induced decays are also supported. The framework additionally allows the addition of mass and mixing corrections induced at higher orders for the involved external states. We explain our procedure to cancel infra-red divergences for such cases, which is achieved through an infra-red counter-term taking into account corrected Goldstone boson vertices. We compare our results for sfermion, gluino and Higgs decays in the minimal supersymmetric standard model (MSSM) against the public codes SFOLD, FVSFOLD and HFOLD and explain observed differences. Radiative induced gluino and neutralino decays are compared against the original implementation in SPheno in the MSSM. We exactly reproduce the results of the code CNNDecays for decays of neutralinos and charginos in R-parity violating models. The new version SARAH 4.11.0 by default includes the calculation of two-body decay widths at the full one-loop level. Current limitations for certain model classes are described.

Generic calculation of two-body partial decay widths at the full one-loop level

Energy Technology Data Exchange (ETDEWEB)

Goodsell, Mark D. [Sorbonne Universites, UPMC Univ Paris 06, UMR 7589, LPTHE, Paris (France); CNRS, UMR 7589, LPTHE, Paris (France); Liebler, Stefan [DESY, Hamburg (Germany); Staub, Florian [Karlsruhe Institute of Technology, Institute for Theoretical Physics (ITP), Karlsruhe (Germany); Karlsruhe Institute of Technology, Institute for Nuclear Physics (IKP), Eggenstein-Leopoldshafen (Germany)

2017-11-15

We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson as well as scalar decays into two fermions, two gauge bosons, two scalars or a scalar and a gauge boson. We present the relevant generic expressions for virtual and real corrections. Whereas wave-function corrections are determined from on-shell conditions, the parameters of the underlying model are by default renormalised in a DR (or MS) scheme. However, the user can also define model-specific counter-terms. As an example we discuss the renormalisation of the electric charge in the Thomson limit for top-quark decays in the standard model. One-loop-induced decays are also supported. The framework additionally allows the addition of mass and mixing corrections induced at higher orders for the involved external states. We explain our procedure to cancel infrared divergences for such cases, which is achieved through an infrared counter-term taking into account corrected Goldstone boson vertices. We compare our results for sfermion, gluino and Higgs decays in the minimal supersymmetric standard model (MSSM) against the public codes SFOLD, FVSFOLD and HFOLD and explain observed differences. Radiatively induced gluino and neutralino decays are compared against the original implementation in SPheno in the MSSM. We exactly reproduce the results of the code CNNDecays for decays of neutralinos and charginos in R-parity violating models. The new version SARAH 4.11.0 by default includes the calculation of two-body decay widths at the full one-loop level. Current limitations for certain model classes are described. (orig.)

Generic calculation of two-body partial decay widths at the full one-loop level

International Nuclear Information System (INIS)

Goodsell, Mark D.; Liebler, Stefan; Staub, Florian; Karlsruhe Institute for Technology, Eggenstein-Leopoldshafen

2017-04-01

We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson as well as scalar decays into two fermions, two gauge bosons, two scalars or a scalar and a gauge boson. We present the relevant generic expressions for virtual and real corrections. Whereas wavefunction corrections are determined from on-shell conditions, the parameters of the underlying model are by default renormalised in a DR (or MS) scheme. However, the user can also define model-specific counter-terms. As an example we discuss the renormalisation of the electric charge in the Thomson limit for top-quark decays in the standard model. One-loop induced decays are also supported. The framework additionally allows the addition of mass and mixing corrections induced at higher orders for the involved external states. We explain our procedure to cancel infra-red divergences for such cases, which is achieved through an infra-red counter-term taking into account corrected Goldstone boson vertices. We compare our results for sfermion, gluino and Higgs decays in the minimal supersymmetric standard model (MSSM) against the public codes SFOLD, FVSFOLD and HFOLD and explain observed differences. Radiative induced gluino and neutralino decays are compared against the original implementation in SPheno in the MSSM. We exactly reproduce the results of the code CNNDecays for decays of neutralinos and charginos in R-parity violating models. The new version SARAH 4.11.0 by default includes the calculation of two-body decay widths at the full one-loop level. Current limitations for certain model classes are described.

Search for neutral Higgs bosons decaying to tau pairs at the CMS experiment

International Nuclear Information System (INIS)

Choudhury, S.

2012-01-01

The thesis describes a study of the tau-pair final state in the semi-leptonic decay mode into muon and hadrons using proton-proton collisions data at a center-of-mass energy of 7 TeV using the CMS detector at the CERN Large Hadron Collider. The performance of tau-lepton reconstruction and identification algorithm is studied using a data sample of proton-proton collisions at √ = 7 TeV, corresponding to an integrated luminosity of 36 pb -1 . The tau leptons that decay into one charged hadron with or without the association of neutral hadrons is reconstructed using Particle-Flow object reconstruction technique with a novel tau identification algorithm called the Hadron Plus Strips (HPS) algorithm in the CMS tracker and electromagnetic calorimeter. The reconstruction efficiency of the algorithm is measured using τ leptons produced in Z-boson decays. The hadronically decaying tau lepton mis-identification rate for jets produced in association with a W boson is also determined. The first measurement of inclusive Z →ττ production in pp collisions at the LHC is presented in muon + hadrons final state using a data sample of 36 pb -1 . The measured cross-section is in good agreement with the next-to-next-to-leading order (NNLO) QCD prediction. After establishing the Z boson in di-tau decay mode, an inclusive search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions is performed at a center-of-mass energy of 7 TeV. The results are based on a data sample corresponding to an integrated luminosity of 36 pb -1 and 4.6 fb -1 recorded by the CMS experiment in the year 2010 and 2011 respectively. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross-section times the branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent bounds in the MSSM parameter space. (author) [fr

β-decay properties in the Cs decay chain

Science.gov (United States)

Benzoni, G.; Lică, R.; Borge, M. J. G.; Fraile, L. M.; IDS Collaboration

2018-02-01

The study of the decay of neutron-rich Cs isotopes has two main objectives: on one side β decay is a perfect tool to access the low-spin structures in the daughter Ba nuclei, where the evolution of octupole deformed shapes can be followed, while, on the other hand, the study of the gross properties of these decays, in terms of decay rates and branching to delayed-neutron emission, are fundamental inputs for the modelling of the r-process in the Rare-Earth Elements peak. Results obtained at CERN-ISOLDE are discussed within this framework and compared to existing data and predictions from state-of-the-art nuclear models.

Single-hole and three-quasiparticle levels in 131Sn observed in the decay of sup(131g,m1,m2)In

International Nuclear Information System (INIS)

Fogelberg, B.; Blomqvist, J.

1984-01-01

The β - decay of mass-separated 131 In has been studied. Three different β-decaying states were found of which one is a high-spin isomer at about 4.1 MeV excitation energy. The level scheme for 131 Sn shows the full set of neutron single-hole levels below about 2.5 MeV and a number of three-quasiparticle levels in the region from about 4 to 7 MeV. The half-life of the 4846.7 keV level was determined to 300 ns. Some data on the decays of 131 Sn and sup(127,129)In are also reported. (orig.)

Conversion electrons from high-statistics β-decay measurements with the 8π spectrometer at TRIUMF-ISAC

Science.gov (United States)

Garrett, P. E.; Jigmeddorj, B.; Radich, A. J.; Andreoiu, C.; Ball, G. C.; Bangay, J. C.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Cross, D. S.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Green, K. L.; Hackman, G.; Hadinia, B.; Leach, K. G.; Michetti-Wilson, J.; Orce, J. N.; Rajabali, M. M.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C.; Svensson, C. E.; Triambak, S.; Wang, Z. M.; Williams, S. J.; Wood, J. L.; Wong, J.; Yates, S. W.; Zganjar, E. F.

2016-09-01

The 8π spectrometer, located at TRIUMF-ISAC, was the world's most powerful spectrometer dedicated to β-decay studies until its decommissioning in early 2014 for replacement with the GRIFFIN array. An integral part of the 8π spectrometer was the Pentagonal Array for Conversion Electron Spectroscopy (PACES) consisting of 5 Si(Li) detectors used for charged-particle detection. PACES enabled both γ - e- and e- - e- coincidence measurements, which were crucial for increasing the sensitivity for discrete e- lines in the presence of large backgrounds. Examples from a 124Cs decay experiment, where the data were vital for the expansion of the 124Cs decay scheme, are shown. With suffcient statistics, measurements of conversion coeffcients can be used to extract the E0 components of Jπ → Jπ transitions for J ≠ 0, which is demonstrated for data obtained in 110In→110Cd decay. With knowledge of the shapes of the states involved, as obtained, for example, from the use of Kumar-Cline shape invariants, the mixing of the states can be extracted.

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

International Nuclear Information System (INIS)

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

1978-01-01

The excited levels in 233 P a following the 237 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 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

Neutron density decay constant in a non-multiplying lattice of finite size

International Nuclear Information System (INIS)

Deniz, V.C.

1965-01-01

This report presents a general theory, using the integral transport method, for obtaining the neutron density decay constant in a finite non-multiplying lattice. The theory is applied to obtain the expression for the diffusion coefficient. The case of a homogeneous medium with 1/v absorption and of finite size in all directions is treated in detail, assuming an isotropic scattering law. The decay constant is obtained up to the B 6 term. The expressions for the diffusion coefficient and for the diffusion cooling coefficient are the same as those obtained for a slab geometry by Nelkin, using the expansion in spherical harmonics of the Fourier transform in the spatial variable. Furthermore, explicit forms are obtained for the flux and the current. It is shown that the deviation of the actual flux from a Maxwellian is the flux generated in the medium, extended to infinity and deprived of its absorbing power, by various sources, each of which has a zero integral over all velocities. The study of the current permits the generalization of Fick's law. An independent integral method, valid for homogeneous media, is also presented. (author) [fr

Evaluation of triggering schemes for KM3NeT

Energy Technology Data Exchange (ETDEWEB)

Seitz, T., E-mail: Thomas.Seitz@physik.uni-erlangen.de [Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Herold, B., E-mail: Bjoern.Herold@physik.uni-erlangen.de [Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Shanidze, R., E-mail: shanidze@physik.uni-erlangen.de [Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

2013-10-11

The future neutrino telescope KM3NeT, to be built in the Mediterranean Sea, will be the largest of its kind. It will include nearly two hundred thousand photomultiplier tubes (PMT) mounted in multi-PMT digital optical modules (DOM). The dominant source of the PMT signals is decays of {sup 40}K and marine fauna bioluminescence. Selection of neutrino and muon events from this continuous optical background signals requires the implementation of fast and efficient triggers. Various schemes for the filtering of background data and the selection of neutrino and muon events were evaluated for the KM3NeT telescope using Monte Carlo simulations.

Nuclear structure from radioactive decay. Annual progress report

International Nuclear Information System (INIS)

Wood, J.L.

1986-01-01

The primary focus has been studies of intruder states and shape coexistence in the neutron-deficient Z equal to 82 region. Most notably, the structure of the neutron-deficient Au isotopes has been studied by on-line decay scheme spectroscopy of mass-separated isotopes at UNISOR, by on-line low-temperature nuclear orientation of mass-separated isotopes at LISOL, and by on-line laser atomic hyperfine spectroscopy of mass-separated isotopes at ISOLDE. Theoretical studies of neutron-deficient Au isotopes have been made. The most dramatic result is the observation of a sudden large increase in the mean-square charge radius between 187 Au and 186 Au, seen in the laser spectroscopy measurements as ISOLDE

Nuclear structure from radioactive decay: Annual progress report

International Nuclear Information System (INIS)

Wood, J.L.

1987-01-01

The primary focus this year has been studies of intruder states and shape coexistence in the neutron-deficient Z ∼ 82 region. Most notably, the existence and conditions for the occurrence of electric monopole (E0) transitions have been considerably clarified. This has been a topic of considerable confusion. On-line decay scheme spectroscopy of mass-separated isotopes at UNISOR (in a collaboration with LSU) has now completely resolved all points of disagreement. These studies are part of a larger program directed towards building a complete picture of shape coexistence. It is becoming evident that E0 transitions are a key signature to shape coexistence. Thus, their correct identification and location are crucial

μ→3e and μ→eγ decays in the model with neutrino and heavy neutral leptons mixing

International Nuclear Information System (INIS)

Ovchinnikova, A.A.

1978-01-01

Muon number nonconservation is discussed within the framework of the renormalizable model of Decker and Pestieau. To renormalize this model four heavy leptons are added. Then the gauge group SU(2)xU(1) is considered. Besides standard left doublets, the right ones in which mixing of neutrino and neutral heavy leptons takes place are introduced. In such a scheme the neutral current of charged leptons is a pure vector. Then the branching ratios of μ→3e and μ→eγ decays are evaluated. It has been shown that these quantities greatly depend upon neutrino masses. If neutrino has a mass about 0.65 MeV, the μ→eγ decay probability may well be close to its experimentally determined upper limit. It this model the μ→3e decay rate is a/π times less than the μ→eγ decay rate

In-trap decay spectroscopy for {beta}{beta} decays

Energy Technology Data Exchange (ETDEWEB)

Brunner, Thomas

2011-01-18

The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

In-trap decay spectroscopy for ββ decays

International Nuclear Information System (INIS)

Brunner, Thomas

2011-01-01

The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in ββ decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from β decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and β detection with almost no β-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in ββ decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in ββ decays. These branches are typically of the order of 10 -5 and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating β background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge detectors, for the detection of X-rays, were

Decay tank

International Nuclear Information System (INIS)

Matsumura, Seiichi; Tagishi, Akinori; Sakata, Yuji; Kontani, Koji; Sudo, Yukio; Kaminaga, Masanori; Kameyama, Iwao; Ando, Koei; Ishiki, Masahiko.

1990-01-01

The present invention concerns an decay tank for decaying a radioactivity concentration of a fluid containing radioactive material. The inside of an decay tank body is partitioned by partitioning plates to form a flow channel. A porous plate is attached at the portion above the end of the partitioning plate, that is, a portion where the flow is just turned. A part of the porous plate has a slit-like opening on the side close to the partitioning plate, that is, the inner side of the flow at the turning portion thereof. Accordingly, the primary coolants passed through the pool type nuclear reactor and flown into the decay tank are flow caused to uniformly over the entire part of the tank without causing swirling. Since a distribution in a staying time is thus decreased, the effect of decaying 16 N as radioactive nuclides in the primary coolants is increased even in a limited volume of the tank. (I.N.)

β-decay spectroscopy of neutron-rich 160,161,162Sm isotopes

Directory of Open Access Journals (Sweden)

Patel Z.

2016-01-01

Full Text Available Neutron-rich 160,161,162Sm isotopes have been populated at the RIBF, RIKEN via β first time. β-coincident γ rays were observed in all three isotopes including γ rays from the isomeric decay of 160Sm and 162Sm. The isomers in 160Sm and 162Sm have previously been observed but have been populated via β decay for the first time. The isomeric state in 162Sm is assigned a 4−v72+[ 633 ]⊗v12−[ 521 ]${4^ - }v{{7 \\over 2}^ + }\\left[ {633} \\right] \\otimes v{{1 \\over 2}^ - }\\left[ {521} \\right]$ configuration based on the decay pattern. The level schemes of 160Sm and 162Sm are presented. The ground states in the parent nuclei 160Pm and 162Pm are both assigned a 6−v72+[633]⊗π52−[532]${6^ - }v{{7 \\over 2}^ + }\\left[ {633} \\right] \\otimes \\pi {{5 \\over 2}^ - }\\left[ {532} \\right]$ configuration based on the population of states in the daughter nuclei. Blocked BCS calculations were performed to further investigate the spin-parities of the ground states in 160Pm, 161Pm, and 162Pm, and the isomeric state in 162Sm

On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

Directory of Open Access Journals (Sweden)

Wang Daoshun

2010-01-01

Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

Role of various Dirac covariants in the BS wave functions in decay constant calculations of pseudoscalar mesons using a power counting scheme

International Nuclear Information System (INIS)

Bhatnagar, S.; Mahecha, J.

2008-09-01

We have employed the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz to calculate the leptonic decay constants of unequal mass pseudoscalar mesons. In the Dirac structure of BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated incorporating both Leading Order (LO) as well as Next-to-leading Order (NLO) Dirac covariants. The contribution of both LO as well as NLO covariants to decay constants are studied in detail in this paper. The results are found to improve dramatically, and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function of a hadron. (author)

aCORN: An experiment to measure the electron-antineutrino correlation coefficient in free neutron decay.

Science.gov (United States)

Collett, B; Bateman, F; Bauder, W K; Byrne, J; Byron, W A; Chen, W; Darius, G; DeAngelis, C; Dewey, M S; Gentile, T R; Hassan, M T; Jones, G L; Komives, A; Laptev, A; Mendenhall, M P; Nico, J S; Noid, G; Park, H; Stephenson, E J; Stern, I; Stockton, K J S; Trull, C; Wietfeldt, F E; Yerozolimsky, B G

2017-08-01

We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.

Search for two-{gamma} sum-energy peaks in the decay out of superdeformed bands

Energy Technology Data Exchange (ETDEWEB)

Blumenthal, D.; Khoo, T.L.; Lauritsen, T. [and others

1995-08-01

The spectrum of {gamma}rays decaying out of the superdeformed (SD) band in {sup 192}Hg has a quasicontinuous distribution. Whereas methods to construct level schemes from discrete lines in coincidence spectra are well established, new techniques must still be developed to extract information from coincidences involving quasicontinuous {gamma}rays. From an experiment using Eurogam, we obtained impressively clean 1- and 2-dimensional {gamma} spectra from pairwise or single gates, respectively, on the transitions of the SD band in {sup 192}Hg. We investigated methods to exploit the 2-dimensional quasicontinuum spectra coincident with the SD band to determine the excitation energy of the SD band above the normal yrast line. No strong peaks were observed in the 2-{gamma} sum spectra; only candidates of peaks at a 2-3 {sigma} level were found. This suggests that 2-{gamma} decay is not the dominant decay branch out of SD bands, consistent with the observed multiplicity of 3.2. We shall next search for peaks in sum-spectra of 3 {gamma}s.

Analysis of core calculation schemes for advanced water reactors

International Nuclear Information System (INIS)

Nicolas, Anne

1989-01-01

This research thesis addresses the analysis of the core control of sub-moderated water reactors with plutonium fuel and varying spectrum. Firstly, a calculation scheme is defined, based on transport theory for the three existing assembly configurations. It is based on the efficiency analysis of the control cluster and of the flow sheet shape in the assembly. Secondly, studies of the assembly with control cluster and within a theory of diffusion with homogenization or detailed assembly representation are performed by taking the environment into account in order to assess errors. Thirdly, due to the presence of a very efficient absorbent in control clusters, a deeper physical analysis requires the study of the flow gradient existing at the interface between assemblies. A parameter is defined to assess this gradient, and theoretically calculated by using finite elements. Developed software is validated [fr

The ηc → pp-bar decay and a quark-diquark model of the nucleon: the contribution of scalar-vector diquark transition

International Nuclear Information System (INIS)

Anselmino, M.; Soares, J.; Caruso, F.; Joffily, S.

1991-01-01

The η c decay into proton-antiproton cannot be explained by a lowest order perturbative QCD quark scheme. Trying to improve a previous result where diquarks were also considered as nucleon's constituents, the contribution of the spin-flip transition between scalar and vector diquarks inside the nucleon is computed and is shown to be strictly zero. This result excludes the possibility of understanding why this decay is experimentally observed with a branching ratio much greater than those of other charmonium decays into the same final state, X0,1,2 → pp-bar, successfully described by pQCD in terms of quark and diquark components of the protons. A theoretical explanation of this decay rate is then still lacking and it is suggested that pseudoscalar glueballs might play an important role in solving the puzzle. The experimental results are also briefly discussed. (author)

Hadronic decay of late-decaying particles and big-bang nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Kawasaki, Masahiro [Research Center for the Early Universe, Graduate School of Science, University of Tokyo, Tokyo 113-0033 (Japan)]. E-mail: masahiro_kawasaki@mac.com; Kohri, Kazunori [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Moroi, Takeo [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2005-10-06

We study the big-bang nucleosynthesis (BBN) scenario with late-decaying exotic particles with lifetime longer than {approx}1 s. With a late-decaying particle in the early universe, predictions of the standard BBN scenario can be significantly altered. Therefore, we derive constraints on its primordial abundance. We pay particular attention to hadronic decay modes of such particles. We see that the non-thermal production process of D, {sup 3}He and {sup 6}Li provides a stringent upper bound on the primordial abundance of late-decaying particles with hadronic branching ratio.

Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

International Nuclear Information System (INIS)

Endo, Akira; Yamaguchi, Yasuhiro

2001-03-01

New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of α particles, β particles, γ rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt γ rays, delayed γ rays, and β particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

Energy Technology Data Exchange (ETDEWEB)

Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-03-01

New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

Rare decays and CP asymmetries in charged B decays

International Nuclear Information System (INIS)

Deshpande, N.G.

1991-01-01

The theory of loop induced rare decays and the rate asymmetry due to CP violation in charged B Decays in reviewed. After considering b → sγ and b → se + e - decays, the asymmetries for pure penguin process are estimated first. A larger asymmetry can result in those modes where a tree diagram and a penguin diagram interfere, however these estimates are necessarily model dependent. Estimates of Cabbibo suppressed penguins are also considered

Study of the shock ignition scheme in inertial confinement fusion

International Nuclear Information System (INIS)

Lafon, M.

2011-01-01

The Shock Ignition (SI) scheme is an alternative to classical ignition schemes in Inertial Confinement Fusion. Its singularity relies on the relaxation of constraints during the compression phase and fulfilment of ignition conditions by launching a short and intense laser pulse (∼500 ps, ∼300 TW) on the pre-assembled fuel at the end of the implosion.In this thesis, it has been established that the SI process leads to a non-isobaric fuel configuration at the ignition time thus modifying the ignition criteria of Deuterium-Tritium (DT) against the conventional schemes. A gain model has been developed and gain curves have been inferred and numerically validated. This hydrodynamical modeling has demonstrated that the SI process allows higher gain and lower ignition energy threshold than conventional ignition due to the high hot spot pressure at ignition time resulting from the ignitor shock propagation.The radiative hydrodynamic CHIC code developed at the CELIA laboratory has been used to determine parametric dependences describing the optimal conditions for target design leading to ignition. These numerical studies have enlightened the potential of SI with regards to saving up laser energy, obtain high gains but also to safety margins and ignition robustness.Finally, the results of the first SI experiments performed in spherical geometry on the OMEGA laser facility (NY, USA) are presented. An interpretation of the experimental data is proposed from mono and bidimensional hydrodynamic simulations. Then, different trails are explored to account for the differences observed between experimental and numerical data and alternative solutions to improve performances are suggested. (author) [fr

a Search for Nucleon Decay with Multiple Muon Decays

Science.gov (United States)

Phillips, Thomas James

A search was made for nucleon decays which result in multiple delayed muon decays using the HPW (Harvard -Purdue-Wisconsin) water Cerenkov detector. The HPW detector consists of 680 metric tons of purified water instrumented with 704 five-inch photomultiplier tubes. The phototubes are situated on a volume array with a lattice spacing of approximately one meter, and the inside walls of the detector are lined with mirrors. This combination of mirrors and a volume array of phototubes gives the HPW detector a low trigger energy threshold and a high muon decay detection efficiency. The detector is surrounded by wire chambers to provide an active shield, and is located at a depth of 1500 meters-of-water-equivalent in the Silver King Mine in Park City, Utah. The entire HPW data set, consisting of 17.2 million events collec- ted during 282 live days between May 1983 and October 1984, was analyzed. No contained events with multiple muon decays were found in a 180 ton fiducial volume. This is consistent with the background rate from neutrino interactions, which is expected to be 0.7 (+OR-) 0.2 events. The calculated lower lifetime limit for the decay mode p (--->) (mu)('+)(mu)('+)(mu)('-) is: (tau)/B.R. = 1 x 10('31) years (90% C.L.). Limits are calculated for ten other proton decay modes and five bound neutron decay modes, most of which are around 4 x 10('30) years (90% C.L.). No previous studies have reported results from direct searches for eight of these modes.

A fully discrete energy stable scheme for a phase filed moving contact line model with variable densities and viscosities

KAUST Repository

Zhu, Guangpu

2018-01-26

In this paper, a fully discrete scheme which considers temporal and spatial discretizations is presented for the coupled Cahn-Hilliard equation in conserved form with the dynamic contact line condition and the Navier-Stokes equation with the generalized Navier boundary condition. Variable densities and viscosities are incorporated in this model. A rigorous proof of energy stability is provided for the fully discrete scheme based on a semi-implicit temporal discretization and a finite difference method on the staggered grids for the spatial discretization. A splitting method based on the pressure stabilization is implemented to solve the Navier-Stokes equation, while the stabilization approach is also used for the Cahn-Hilliard equation. Numerical results in both 2-D and 3-D demonstrate the accuracy, efficiency and decaying property of discrete energy of the proposed scheme.

Renormalization scheme-dependence of perturbative quantum chromodynamics corrections to quarkonia

International Nuclear Information System (INIS)

Dentamaro, A.V.

1985-05-01

QCD radiative corrections to physical quantities are studied using Stevenson's principle of minimal sensitivity (PMS) to define the renormalization. We examine several naive potentials (Cornell group, power law and logarithmic), as well as the more sophisticated Richardson model in order to determine the spectra for the non-relativistic heavy charmonium and bottomonium systems. Predictions are made for the values of hyperfine splittings, leptonic and hadronic decay widths and E1 transition rates for these families of mesons. It is shown that good agreement with experimental data may be achieved by using a constant value of Λ/sub QCD/, which is determined by the PMS scheme and the potential model

Radioactive Decay

Science.gov (United States)

Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

Measurements of multipolarities in 227Ra as tests of evidence for stable octupole deformation

International Nuclear Information System (INIS)

Borge, M.J.G.; Burke, D.G.; Gietz, H.; Hill, P.; Kaffrell, N.

1987-01-01

Multipolarities of ∝30 transitions in 227 Ra have been established by measuring conversion electrons following the β - decay of 227 Fr. For this purpose a 'mini-orange'-type electron spectrometer has been constructed. The 227 Fr isotopes were produced by the ISOLDE on-line separator at the CERN Synchro-cyclotron. Internal conversion coefficients were obtained from singles spectra and also from simultaneous γe - and γγ coincidence measurements. The new results support the placement of levels and transitions in the earlier level scheme but require changes in the previously assigned parities for four of the levels. Also, one E0 transition was identified. The results are consistent with previous interpretations for most of the levels that have been used to argue in favour of a small permanent octupole deformation for 227 Ra. (orig.)

Hadron energy spectrum in polarized top-quark decays considering the effects of hadron and bottom quark masses

Energy Technology Data Exchange (ETDEWEB)

Nejad, S.M.M. [Yazd University, Faculty of Physics, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, P.O.Box 19395-5531, Tehran (Iran, Islamic Republic of); Balali, Mahboobe [Yazd University, Faculty of Physics, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

2016-03-15

We present the analytical expressions for the next-to-leading order corrections to the partial decay width t(↑) → bW{sup +}, followed by b @→ H{sub b}X, for nonzero b-quark mass (m{sub b} ≠ 0) in the fixed-flavor-number scheme (FFNs). To make the predictions for the energy distribution of outgoing hadrons H{sub b}, as a function of the normalized H{sub b}-energy fraction x{sub H}, we apply the general-mass variable-flavor-number scheme (GM-VFNs) in a specific helicity coordinate system where the polarization of top quark is evaluated relative to the b-quark momentum. We also study the effects of gluon fragmentation and finite hadron mass on the hadron energy spectrum so that hadron masses are responsible for the low x{sub H} threshold. In order to describe both the b-quark and the gluon hadronizations in top decays we apply realistic and nonperturbative fragmentation functions extracted through a global fit to the e{sup +}e{sup -} annihilation data from CERN LEP1 and SLAC SLC by relying on their universality and scaling violations. (orig.)

Off-lattice pattern recognition scheme for kinetic Monte Carlo simulations

International Nuclear Information System (INIS)

Nandipati, Giridhar; Kara, Abdelkader; Shah, Syed Islamuddin; Rahman, Talat S.

2012-01-01

We report the development of a pattern-recognition scheme for the off-lattice self-learning kinetic Monte Carlo (KMC) method, one that is simple and flexible enough that it can be applied to all types of surfaces. In this scheme, to uniquely identify the local environment and associated processes involving three-dimensional (3D) motion of an atom or atoms, space around a central atom is divided into 3D rectangular boxes. The dimensions and the number of 3D boxes are determined by the accuracy with which a process needs to be identified and a process is described as the central atom moving to a neighboring vacant box accompanied by the motion of any other atom or atoms in its surrounding boxes. As a test of this method to we apply it to examine the decay of 3D Cu islands on the Cu(100) and to the surface diffusion of a Cu monomer and a dimer on Cu(111) and compare the results and computational efficiency to those available in the literature.

Electroweak one-loop corrections to the decay of the charged vector boson

International Nuclear Information System (INIS)

Bardin, D.Yu.; Riemann, S.; Riemann, T.

1986-01-01

The electroweak radiative corrections to the decay widths of the W-boson, GITA(W → lanti v, anti ud, anti cs), have been calculated in the standard theory. The results are presented in terms of an electroweak form factor rhosup(W), and their dependence on msub(t) and Msub(Hsub(W)) (masses of t-quark and higgs boson) is studied. Typically value of rhosup(W)-1 is of an order of one per cent. The difference rhosub(qq')sup(W) is negligible, 0.045%. The calculational scheme used is described in detail

Investigation of the accumulation kinetics of free radicals under irradiation of some polymethylmethacrylate co-polymers in the 270-400 K temperature range

Energy Technology Data Exchange (ETDEWEB)

Pivovarov, S P; Poljakov, A I; Rjabikin, Y A; Philippov, N L; Bitenbaev, M I [AN Kazakhskoj SSR, Alma-Ata. Inst. Yadernoj Fiziki

1982-02-01

In the present work, anomalous shapes of free radical (FR) accumulation curves found under PMMA copolymers irradiation in the T >= 300/sup 0/ K temperature range have been studied. With the irradiation dose increase the FR concentration in PMMA increases up to a definite maximal value and then starts falling. It is stated that appearance of slopes on the FR accumulation curves is not associated with possible changes of the FR relaxation characteristics. The second order of the FR decay reactions is estimated with the activation energy E = 8.3 kcal/mol. It is suggested that the FR decay processes in the irradiation temperature range T >= 300/sup 0/ K are due to the fast decay of macrochains according to the 'unzipping' mechanism.

Investigation of the accumulation kinetics of free radicals under irradiation of some polymethylmethacrylate co-polymers in the 270-400 K temperature range

International Nuclear Information System (INIS)

Pivovarov, S.P.; Poljakov, A.I.; Rjabikin, Y.A.; Philippov, N.L.; Bitenbaev, M.I.

1982-01-01

In the present work, anomalous shapes of free radical (FR) accumulation curves found under PMMA copolymers irradiation in the T >= 300 0 K temperature range have been studied. With the irradiation dose increase the FR concentration in PMMA increases up to a definite maximal value and then starts falling. It is stated that appearance of slopes on the FR accumulation curves is not associated with possible changes of the FR relaxation characteristics. The second order of the FR decay reactions is estimated with the activation energy E = 8.3 kcal/mol. It is suggested that the FR decay processes in the irradiation temperature range T >= 300 0 K are due to the fast decay of macrochains according to the 'unzipping' mechanism. (author)

The Monte-Carlo code DECAY to simulate the decay of baryon and meson resonances

International Nuclear Information System (INIS)

Haenssgen, K.; Ritter, S.

1983-01-01

The code DECAY simulates the decay of unpolarized baryon and meson resonances in the laboratory frame. DECAY treats some resonances among these all baryon resonances of the spin 3/2 + decuplet and all meson resonances of the spin 1 - nonet. A given resonance decays via two or three particle decay steps until all decay products are stable particles. Program summary and code description are given. (author)

Decay of hypernuclei

International Nuclear Information System (INIS)

Bando, H.

1985-01-01

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.)

Implementation of a turbulent orographic form drag scheme in WRF and its application to the Tibetan Plateau

Science.gov (United States)

Zhou, Xu; Yang, Kun; Wang, Yan

2018-04-01

Sub-grid-scale orographic variation (smaller than 5 km) exerts turbulent form drag on atmospheric flows and significantly retards the wind speed. The Weather Research and Forecasting model (WRF) includes a turbulent orographic form drag (TOFD) scheme that adds the drag to the surface layer. In this study, another TOFD scheme has been incorporated in WRF3.7, which exerts an exponentially decaying drag from the surface layer to upper layers. To investigate the effect of the new scheme, WRF with the old scheme and with the new one was used to simulate the climate over the complex terrain of the Tibetan Plateau from May to October 2010. The two schemes were evaluated in terms of the direct impact (on wind fields) and the indirect impact (on air temperature and precipitation). The new TOFD scheme alleviates the mean bias in the surface wind components, and clearly reduces the root mean square error (RMSEs) in seasonal mean wind speed (from 1.10 to 0.76 m s-1), when referring to the station observations. Furthermore, the new TOFD scheme also generally improves the simulation of wind profile, as characterized by smaller biases and RMSEs than the old one when referring to radio sounding data. Meanwhile, the simulated precipitation with the new scheme is improved, with reduced mean bias (from 1.34 to 1.12 mm day-1) and RMSEs, which is due to the weakening of water vapor flux at low-level atmosphere with the new scheme when crossing the Himalayan Mountains. However, the simulation of 2-m air temperature is little improved.

Two loop O(αsGFmt2) corrections to the fermionic decay rates of the standard-model Higgs boson

International Nuclear Information System (INIS)

Kniehl, B.A.

1994-05-01

Low- and intermediate mass Higgs bosons decay preferably into fermion pairs. The one-loop electroweak corrections to the respective decay rates are dominated by a flavour-independent term of O(G F m t 2 ). We calculate the two-loop gluon correction to this term. It turns out that this correction screens the leading high-m t behaviour of the one-loop result by roughly 10%. We also present the two-loop QCD correction to the contribution induced by a pair of fourth-generation quarks with arbitrary masses. As expected, the inclusion of the QCD correction considerably reduces the renormalization-scheme dependence of the prediction. (orig.)

The next enriched xenon observatory. A search for neutrinoless double beta decay

Energy Technology Data Exchange (ETDEWEB)

Bayerlein, Reimund; Hufschmidt, Patrick; Jamil, Ako; Schneider, Judith; Wagenpfeil, Michael; Wrede, Gerrit; Ziegler, Tobias; Hoessl, Juergen; Anton, Gisela; Michel, Thilo [ECAP, Friedrich-Alexander-Universitaet Erlangen-Nuernberg (Germany)

2016-07-01

The question whether the neutrino could be its own antiparticle is still not answered. The most practical way to test this is the search for the neutrinoless double beta decay. The half-life of this decay is related to the value of a linear combination of the masses of the neutrino mass eigenstates and therefore provides information about the absolute mass scale of neutrinos. The nEXO experiment - the successor of EXO200 - is currently under research and development. The baseline concept comprises a single-phase liquid xenon (LXe) time projection chamber (TPC) filled with about 5 tons of liquid xenon enriched to about 80% Xe-136 as the double beta decay nuclide. In order to fully cover the range of the effective Majorana neutrino mass in the inverted hierarchy scheme, excellent energy resolution is required. Therefore, a position-resolving, low-noise charge readout and very efficient light collection and detection are mandatory. For the purpose of very low background levels radiopure Silicon Photomultipliers (SiPMs) have to be used to detect the scintillation light of LXe. Due to the large half-life a huge detector mass and long term measurement are needed. In this talk the baseline-concept of the experimental setup is presented.

On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

Energy Technology Data Exchange (ETDEWEB)

Vermeire, B.C., E-mail: brian.vermeire@concordia.ca; Witherden, F.D.; Vincent, P.E.

2017-04-01

First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier–Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor–Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

Science.gov (United States)

Vermeire, B. C.; Witherden, F. D.; Vincent, P. E.

2017-04-01

First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier-Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor-Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

International Nuclear Information System (INIS)

Vermeire, B.C.; Witherden, F.D.; Vincent, P.E.

2017-01-01

First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier–Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor–Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

Study of the odd mass transition nuclei: 185Hg, 187Hg, 189Hg and 183Ir

International Nuclear Information System (INIS)

Zerrouki, A.

1979-01-01

The radioactive decay of 185 Tl, 186 Tl, 187 Tl has been studied on the isotope separator Isocele II working on line with the Orsay synchrocyclotron from Au( 3 He,xn) reactions: the emitted α lines have been measured and the main γ lines belonging to the 187 Tl→ 187 Hg decay have been identified. The 185 Hg, 187 Hg, 189 Hg high spin states have been studied using the following (HI,xn) reactions obtained on the Strasbourg MP Tandem: 168 Er( 24 Mg,xn) 187 Hg, 188 Hg, 166 Er( 24 Mg,xn) 185 Hg, 186 Hg, 157 Gd( 32 S,xn) 184 Hg, 185 Hg, 158 Gd( 32 S,5n) 185 Hg and 175 Lu( 19 F,5n) 189 Hg. The excitation functions are indicated and a high spin level scheme of 189 Hg is proposed: it is compared to the 'quasiparticle + triaxial rotor' model predictions. A level scheme of 183 Ir is proposed from the data collected at Isolde II (CERN) by Dr. SCHUCK: it is analysed within the framework of the same theoretical model used above [fr

Study of some odd-mass nuclei with 51 neutrons or 51 protons

International Nuclear Information System (INIS)

Duffait, Roger.

1976-01-01

The level schemes of 93 Mo, 113 Sb, 115 Sb and 119 Sb nuclei were studied. The knowledge of the sup(93m+g)Tc decays was improved. The 2,0 min 113 Te isotope was produced and studied for the first time; two 115 Te isomers with neighbouring half-lives were found and ambiguities on the 115 Te nature cleared up. The sup(119m+g)Te decays were studied with the help of isotopically separated sources and the 119 Sb level scheme was revised. The 93 Mo and 119 Sb level lifetimes were studied using Doppler-shift attenuation method (DSAM) using (p,nγ) reactions at the Van de Graaff accelerator of the University of Lyon. On the whole 16 lifetimes were measured. The experimental results were interpreted in the unified model by intermediate coupling between particle states and the even-even vibrational core; attempts to improve the interpretation by using a semi-microscopical model with the delta surface interaction were made and the two calculations were compared [fr

Beta-decay and decay heat. Summary report of consultants' meeting

International Nuclear Information System (INIS)

Nicols, A.L.

2006-01-01

Experts on decay data and decay heat calculations participated in a Consultants' Meeting organized at IAEA Headquarters on 12-14 December 2005. Debate focused on the validation of decay heat calculations as a function of cooling time for fuel irradiated in power reactors through comparisons with experimental benchmark data. Both the current understanding and quantification of mean beta and gamma decay energies were reviewed with respect to measurements and the Gross Theory of Beta Decay. Particular emphasis was placed on the known development of total absorption gamma-ray spectroscopy (TAGS), and detailed discussions took place to formulate the measurement requirements for mean beta and gamma data of individual radionuclides. This meeting was organized in cooperation with the OECD/NEA Working Party for Evaluation and Cooperation (WPEC). Proposals and recommendations were made to resolve particular difficulties, and an initial list of fission products was produced for TAGS studies. The discussions, conclusions and recommendations of the meeting are briefly described in this report. (author)

CP violation in K decays and rare decays

International Nuclear Information System (INIS)

Buchalla, G.

1996-12-01

The present status of CP violation in decays of neutral kaons is reviewed. In addition selected rare decays of both K and B mesons are discussed. The emphasis is in particular on observables that can be reliably calculated and thus offer the possibility of clean tests of standard model flavor physics. 105 refs

High-resolution positron Q-value measurements and nuclear-structure studies far from the stability line. Progress report

International Nuclear Information System (INIS)

Avignone, F.T. III.

1981-01-01

Extensive data analysis and theoretical analysis has been done to complete the extensive decay scheme investigation of 206 208 Fr and the level structures of 206 208 Rn. A final version of a journal article is presented in preprint form. Extensive Monte Carlo calculations have been made to correct the end point energies of positron spectra taken with intrinsic Ge detectors for annihilation radiation interferences. These calculations were tested using the decay of 82 Sr which has previously measured positron branches. This technique was applied to the positron spectra collected at the on-line UNISOR isotope separator. The reactions used were 60 Ni( 20 Ne;p2n) 77 Rb and 60 Ni( 20 Ne;pn) 78 Rb. Values for 5, γ-β + coincidence positron end point energies are given for the decay of 77 Rb. The implied Q-value is 5.075 +- 0.010 MeV. A complete paper on the calculated corrections is presented. A flow chart of a more complete program which accounts for positrons scattering out of the detector and for bremsstralung radiation is also presented. End-point energies of four β + branches in 77 Rb are given as well as a proposed energy level scheme of 75 Kr based on γ-γ coincidence data taken at UNISOR

Charm Decays at BABAR

International Nuclear Information System (INIS)

Charles, M.

2004-01-01

The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D 0 → l + l - are presented and new upper limits on these processes are established. Second, a measurement of the branching fraction of the isospin-violating hadronic decay D* s (2112) + → D s + π 0 relative to the radiative decay D* s (2112) + → D s + γ is made. Third, the decays of D* sJ (2317) + and D sJ (2460) + mesons are studied and ratios of branching fractions are measured. Fourth, Cabibbo-suppressed decays of the Λ c + are examined and their branching fractions measured relative to Cabibbo-allowed modes. Fifth, the Χ c 0 is studied through its decays to Χ - π + and (Omega) - K + ; in addition to measuring the ratio of branching fractions for Χ c 0 produced from the c(bar c) continuum, the uncorrected momentum spectrum is measured, providing clear confirmation of Χ c 0 production in B decays

Rare B decays, rare τ decays, and grand unification

International Nuclear Information System (INIS)

Sher, M.; Yuan, Y.

1991-01-01

In multi-Higgs-boson extensions of the standard model, tree-level flavor-changing neutral currents exist naturally, unless suppressed by some symmetry. For a given rate, the exchanged scalar or pseudoscalar mass is very sensitive to the flavor-changing coupling between the first two generations. Since the Yukawa couplings of the first two generations are unknown and certainly very small, bounds which rely on some assumed value of this flavor-changing coupling are quite dubious. One might expect the size (and reliability) of the Yukawa couplings involving the third generation to be greater. In this paper, we consider processes involving τ's and B's, and determine the bounds on the flavor-changing couplings which involve third-generation fields. The strongest bound in the quark sector comes from B-bar B mixing and in the lepton sector, surprisingly, from μ→eγ. It is then noted that the flavor-changing couplings in the quark sector are related to those in the lepton sector in many grand unified theories, and one can ask whether an analysis of rare τ decays or rare B decays will provide the strongest constraints. We show that rare B decays provide the strongest bounds, and that no useful information can be obtained from rare τ decays. It is also noted that the most promising decay modes are B→Kμτ and B s →μτ, and we urge experimenters to look for rare decay modes of the B in which a τ is in the final state

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

Measurement of free neutron lifetime by electron decay detection with a migration chamber

International Nuclear Information System (INIS)

Grivot, P.

1988-01-01

In this study, the different aspects of the realization of the experimental setup are successively described: creation of a pulsed monochromatic neutron beam, design and construction of a detector for neutron decay electrons, development of electronics and of the data acquisition system, measurement of the helium-3 density in a gaseous mixture. A mechanical system called double chopper and a monochromator crystal are used to obtain neutron bursts with a length of about 28 cm and a velocity of 846 m/s. The electron detector is a time projection chamber (TPC) filled at atmospheric pressure with a helium-4 (93%), helium-3 (10 -5 %) and carbon dioxide (7%) mixture. The problems encountered during the data acquisition with the neutron beam and preliminary results from analysis are also presented [fr

Genetic effects of decay of tritium incorporated into cells of yeast Saccharomyces cerevisiae. 5. Lethal and mutagenic effects and the nature of mutations induced by /sup 3/H decay in the 6-th position of thymine

Energy Technology Data Exchange (ETDEWEB)

Ivanov, E.L.; Korolev, V.G. (AN SSSR, Leningrad. Inst. Yadernoj Fiziki)

1982-03-01

Lethal and mutagenous effects as well as nature of mutations induced with /sup 3/H decay in the sixth position of thymine (6-/sup 3/H-T) have been studied. Inactivation probability of haploid yeasts constituted ..cap alpha..=(6.1+-1.0)x10/sup -3/ decay/sup -1/ or ..cap alpha..=(7.6+-1.3)x10/sup -5/ rad/sup -1/, and probability of mutation appearance in genes ade 1, ade -K is (2.8+-1.7)x10/sup -8/ decay/sup -1/ or K=(3.5+-2.1)x10/sup -10/ rad/sup -1/. Lethal and mutageneous effects of 6-/sup 3/H-T don't differ considerably from those for /sup 3/H decay in the fifth position of thymine (5-/sup 3/H-T). From the point of view of frequency of transversions and mutations of read-out frame shift type induced in ade 2 gene, 6-/sup 3/H-T doesn't differ from 5-/sup 3/H-T. However, in comparison with the latter 6-/sup 3/H-T causes appearance of a larger amount of AT ..-->.. GTs transitions. A scheme, according to which 5 methyl barbituric acid (5MBK) is a finite product of /sup 3/H decay in the sixth position of thymine, is suggested. The results obtained point to that fact that 5MBK represents weak mutageneous damage of thymine causing the exchange of AT pair.

β decay and isomeric properties of neutron-rich Ca and Sc isotopes

International Nuclear Information System (INIS)

Crawford, H. L.; Mantica, P. F.; Berryman, J. S.; Stoker, J. B.; Janssens, R. V. F.; Carpenter, M. P.; Kay, B. P.; Lauritsen, T.; Zhu, S.; Broda, R.; Cieplicka, N.; Fornal, B.; Grinyer, G. F.; Minamisono, K.; Hoteling, N.; Stefanescu, I.; Walters, W. B.

2010-01-01

The isomeric and β-decay properties of neutron-rich 53-57 Sc and 53,54 Ca nuclei near neutron number N=32 are reported, and the low-energy level schemes of 53,54,56 Sc and 53-57 Ti are presented. The low-energy level structures of the 21 Sc isotopes are discussed in terms of the coupling of the valence 1f 7/2 proton to states in the corresponding 20 Ca cores. Implications with respect to the robustness of the N=32 subshell closure are discussed, as well as the repercussions for a possible N=34 subshell closure.

Visual cues for woodpeckers: light reflectance of decayed wood varies by decay fungus

Science.gov (United States)

O'Daniels, Sean T.; Kesler, Dylan C.; Mihail, Jeanne D.; Webb, Elisabeth B.; Werner, Scott J.

2018-01-01

The appearance of wood substrates is likely relevant to bird species with life histories that require regular interactions with wood for food and shelter. Woodpeckers detect decayed wood for cavity placement or foraging, and some species may be capable of detecting trees decayed by specific fungi; however, a mechanism allowing for such specificity remains unidentified. We hypothesized that decay fungi associated with woodpecker cavity sites alter the substrate reflectance in a species-specific manner that is visually discriminable by woodpeckers. We grew 10 species of wood decay fungi from pure cultures on sterile wood substrates of 3 tree species. We then measured the relative reflectance spectra of decayed and control wood wafers and compared them using the receptor noise-limited (RNL) color discrimination model. The RNL model has been used in studies of feather coloration, egg shells, flowers, and fruit to model how the colors of objects appear to birds. Our analyses indicated 6 of 10 decayed substrate/control comparisons were above the threshold of discrimination (i.e., indicating differences discriminable by avian viewers), and 12 of 13 decayed substrate comparisons were also above threshold for a hypothetical woodpecker. We conclude that woodpeckers should be capable of visually detecting decayed wood on trees where bark is absent, and they should also be able to detect visually species-specific differences in wood substrates decayed by fungi used in this study. Our results provide evidence for a visual mechanism by which woodpeckers could identify and select substrates decayed by specific fungi, which has implications for understanding ecologically important woodpecker–fungus interactions.

Properties of low-lying intruder states in $^{34}$Al and $^{34}$Si sequentially populated in $\\beta$-decay of $^{34}$Mg

CERN Multimedia

A low-lying long-lived (26±1 ms) isomer in $^{34}$Al has been observed recently and assigned as 1$^{+}$ state of intruder character. It was populated in $^{36}$S fragmentation and feeds, in $\\beta$-decay, the 0$_{2}^{+}$ state in $^{34}$Si whose excitation energy and lifetime were determined in an electron-positron pairs spectroscopy experiment. In the present experiment we intend to measure for the first time the $\\gamma$-rays following the $\\beta$-decay of $^{34}$Mg. Despite the interest for $^{34}$Mg, the up-right corner of the “N$\\thicksim$20 island of inversion”, the only information on its $\\beta$-decay is the lifetime of 20±10 ms, determined from $\\beta$-neutron coincidences. As a result of the proposed experiment, we expect to place the first transitions in the level scheme of $^{34}$Al and to strongly populate the newly observed isomer, measuring its excitation energy, if the branching ratio to 4$^{−}$ ground state is significant. Theoretical estimations for the $\\beta$-decay of the new isome...

Rare Decays at LHCb

CERN Document Server

Belyaev, Ivan

2006-01-01

Rare loop-induced decays are sensitive to New Physics in many Standard Model extensions. In this paper we discuss the reconstruction of the radiative penguin decays $B^0_d \\to K^{*0} \\gamma, B^0_s \\to \\phi \\gamma , B^0_d \\to \\omega \\gamma, \\Lambda_b \\to \\Lambda \\gamma$, the electroweak penguin decays $B^0_d \\to K^{*0} \\mu^+ \\mu^-, B^+_u \\to K^+ \\mu^+ \\mu^-$, the gluonic penguin decays $B^0_d \\to \\phi K^0_S, B^0_s \\to \\phi \\phi$, and the decay $B^0_s \\to \\mu^+\\mu^-$ at LHCb. The selection criteria, evaluated efficiencies, expected annual yields and $B/S$ estimates are presented.

Approximation of bivariate copulas by patched bivariate Fréchet copulas

KAUST Repository

Zheng, Yanting; Yang, Jingping; Huang, Jianhua Z.

2011-01-01

Bivariate Fréchet (BF) copulas characterize dependence as a mixture of three simple structures: comonotonicity, independence and countermonotonicity. They are easily interpretable but have limitations when used as approximations to general dependence structures. To improve the approximation property of the BF copulas and keep the advantage of easy interpretation, we develop a new copula approximation scheme by using BF copulas locally and patching the local pieces together. Error bounds and a probabilistic interpretation of this approximation scheme are developed. The new approximation scheme is compared with several existing copula approximations, including shuffle of min, checkmin, checkerboard and Bernstein approximations and exhibits better performance, especially in characterizing the local dependence. The utility of the new approximation scheme in insurance and finance is illustrated in the computation of the rainbow option prices and stop-loss premiums. © 2010 Elsevier B.V.

Approximation of bivariate copulas by patched bivariate Fréchet copulas

KAUST Repository

Zheng, Yanting

2011-03-01

Bivariate Fréchet (BF) copulas characterize dependence as a mixture of three simple structures: comonotonicity, independence and countermonotonicity. They are easily interpretable but have limitations when used as approximations to general dependence structures. To improve the approximation property of the BF copulas and keep the advantage of easy interpretation, we develop a new copula approximation scheme by using BF copulas locally and patching the local pieces together. Error bounds and a probabilistic interpretation of this approximation scheme are developed. The new approximation scheme is compared with several existing copula approximations, including shuffle of min, checkmin, checkerboard and Bernstein approximations and exhibits better performance, especially in characterizing the local dependence. The utility of the new approximation scheme in insurance and finance is illustrated in the computation of the rainbow option prices and stop-loss premiums. © 2010 Elsevier B.V.

Lethal Effect on Bacterium of Decay of Incorporated Radioactive Atoms (3H, 14C, 32P)

International Nuclear Information System (INIS)

Apelgot, Sonia

1968-01-01

The biological effect of decay of 3 H, 14 C and 32 P incorporated into a bacterium depends on the nature of the organic molecule labelled, on the position of the isotope within it and on the isotope itself. In sum, results obtained to date show that: The decay of 3 H atoms incorporated into certain macromolecules of a bacterium causes sterilization through ionization by the ß - particle emitted; transmutation is of negligible importance. This self-irradiation is comparable in effect with X-rays and is affected in a similar manner by the same factors: temperature, presence of a radioprotector, radiosensitivity of the strain. Decay of 14 C or 32 P atoms incorporated into bacterial DNA is lethal because of the transmutation effect; ionizations produced by emitted ß - particles may be disregarded. Survival curves for 32 P transmutations depend on the experimental conditions. Some of the results obtained with 32 P are similar to those obtained with X-rays, e.g. effects of temperature, radical capture and oxygen, while others are similar to those of u.v. light, e.g., effect of growth conditions. Comparative tests made with 32 P indicate that the recoil energy of transmutation is not the phenomenon responsible for the lethal effect observed. Comparison of the results obtained after X-irradiation or decay of 3 H or 32 P incorporated into the DNA of bacteria of the same strain of E. coli shows that the efficiency of a 32 P transmutation is about four times greater than that of an ionization produced at random within the same DNA. (author) [fr

Asymptotic preserving and all-regime Lagrange-Projection like numerical schemes: application to two-phase flows in low mach regime

International Nuclear Information System (INIS)

Girardin, Mathieu

2014-01-01

Two-phase flows in Pressurized Water Reactors belong to a wide range of Mach number flows. Computing accurate approximate solutions of those flows may be challenging from a numerical point of view as classical finite volume methods are too diffusive in the low Mach regime. In this thesis, we are interested in designing and studying some robust numerical schemes that are stable for large time steps and accurate even on coarse meshes for a wide range of flow regimes. An important feature is the strategy to construct those schemes. We use a mixed implicit-explicit strategy based on an operator splitting to solve fast and slow phenomena separately. Then, we introduce a modification of a Suliciu type relaxation scheme to improve the accuracy of the numerical scheme in some regime of interest. Two approaches have been used to assess the ability of our numerical schemes to deal with a wide range of flow regimes. The first approach, based on the asymptotic preserving property, has been used for the gas dynamics equations with stiff source terms. The second approach, based on the all-regime property, has been used for the gas dynamics equations and the homogeneous two-phase flows models HRM and HEM in the low Mach regime. We obtained some robustness and stability properties for our numerical schemes. In particular, some discrete entropy inequalities are shown. Numerical evidences, in 1D and in 2D on unstructured meshes, assess the gain in term of accuracy and CPU time of those asymptotic preserving and all-regime numerical schemes in comparison with classical finite volume methods. (author) [fr

Evidence for the electromagnetic decay instability driven by two plasmon decay

International Nuclear Information System (INIS)

Baker, K.L.; Afeyan, B.B.; Estabrook, K.G.; Drake, R.P.

1997-01-01

This paper examines the electromagnetic decay instability (EDI) and its role in laser-produced plasmas. The electromagnetic decay instability provides another channel through which parametric instabilities involving Langmuir waves can saturate. In the case where EDI is pumped by the Langmuir waves associated with two plasmon decay, EDI is shown to present an explanation for ω o /2 emission from laser-produced plasmas which is consistent with experimental observations

Measurement of Inclusive Radiative B -Meson Decay B -> X_s gamma

Energy Technology Data Exchange (ETDEWEB)

Ozcan, V.E.; /SLAC /Stanford U., Appl. Phys. Dept.

2006-01-06

Radiative decays of the B meson, B {yields} X{sub s}{gamma}, proceed via virtual flavor changing neutral current processes that are sensitive to contributions from high mass scales, either within the Standard Model of electroweak interactions or beyond. In the Standard Model, these transitions are sensitive to the weak interactions of the top quark, and relatively robust predictions of the inclusive decay rate exist. Significant deviation from these predictions could be interpreted as indications for processes not included in the minimal Standard Model, like interactions of charged Higgs or SUSY particles. The analysis of the inclusive photon spectrum from B {yields} X{sub s}{gamma} decays is rather challenging due to high backgrounds from photons emitted in the decay of mesons in B decays as well as e{sup +}e{sup -} annihilation to low mass quark and lepton pairs. Based on 88.5 million B{bar B} events collected by the BABAR detector, the photon spectrum above 1.9 GeV is presented. By comparison of the first and second moments of the photon spectrum with QCD predictions (calculated in the kinetic scheme), QCD parameters describing the bound state of the b quark in the B meson are extracted: m{sub b} = (4.45 {+-} 0.16) GeV/c{sup 2}; {mu}{sub {pi}}{sup 2} = (0.65 {+-} 0.29) GeV{sup 2}. These parameters are useful input to non-perturbative QCD corrections to the semileptonic B decay rate and the determination of the CKM parameter |V{sub ub}|. Based on these parameters and heavy quark expansion, the full branching fraction is obtained as: {Beta}(B {yields} X{sub s}{gamma}){sup E{sub {gamma}}>1.6 GeV} = (4.05 {+-} 0.32(stat) {+-} 0.38(syst) {+-} 0.29(model)) x 10{sup -4}. This result is in good agreement with previous measurements, the statistical and systematic errors are comparable. It is also in good agreement with the theoretical Standard Model predictions, and thus within the present errors there is no indication of any interactions not accounted for in the

Tau decays

International Nuclear Information System (INIS)

Golutvin, A.

1994-09-01

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.)

Measurement of m_top via neutrino weighting in the dilepton decay channels at DØ

Energy Technology Data Exchange (ETDEWEB)

Temple, Jeffrey Willard [Univ. of Arizona, Tucson, AZ (United States)

2006-01-01

A measurement of the top quark mass from dilepton decay channels is presented, using approximately 360 pb^-1 of data colleced by the DØ experiment at Fermilab. The mass is measured from a total of 21 candidate dilepton events, using the neutrino weighting scheme. The measured mass is found to be 175.6±10.7 (stat.)±6.0(syst.) GeV. This result eement with the current world average of the top quark mass.

Reducing medical claims cost to Ghana?s National Health Insurance scheme: a cross-sectional comparative assessment of the paper- and electronic-based claims reviews

OpenAIRE

Nsiah-Boateng, Eric; Asenso-Boadi, Francis; Dsane-Selby, Lydia; Andoh-Adjei, Francis-Xavier; Otoo, Nathaniel; Akweongo, Patricia; Aikins, Moses

2017-01-01

Background A robust medical claims review system is crucial for addressing fraud and abuse and ensuring financial viability of health insurance organisations. This paper assesses claims adjustment rate of the paper- and electronic-based claims reviews of the National Health Insurance Scheme (NHIS) in Ghana. Methods The study was a cross-sectional comparative assessment of paper- and electronic-based claims reviews of the NHIS. Medical claims of subscribers for the year, 2014 were requested fr...

A Classification Scheme for Glaciological AVA Responses

Science.gov (United States)

Booth, A.; Emir, E.

2014-12-01

A classification scheme is proposed for amplitude vs. angle (AVA) responses as an aid to the interpretation of seismic reflectivity in glaciological research campaigns. AVA responses are a powerful tool in characterising the material properties of glacier ice and its substrate. However, before interpreting AVA data, careful true amplitude processing is required to constrain basal reflectivity and compensate amplitude decay mechanisms, including anelastic attenuation and spherical divergence. These fundamental processing steps can be difficult to design in cases of noisy data, e.g. where a target reflection is contaminated by surface wave energy (in the case of shallow glaciers) or by energy reflected from out of the survey plane. AVA methods have equally powerful usage in estimating the fluid fill of potential hydrocarbon reservoirs. However, such applications seldom use true amplitude data and instead consider qualitative AVA responses using a well-defined classification scheme. Such schemes are often defined in terms of the characteristics of best-fit responses to the observed reflectivity, e.g. the intercept (I) and gradient (G) of a linear approximation to the AVA data. The position of the response on a cross-plot of I and G then offers a diagnostic attribute for certain fluid types. We investigate the advantages in glaciology of emulating this practice, and develop a cross-plot based on the 3-term Shuey AVA approximation (using I, G, and a curvature term C). Model AVA curves define a clear lithification trend: AVA responses to stiff (lithified) substrates fall discretely into one quadrant of the cross-plot, with positive I and negative G, whereas those to fluid-rich substrates plot diagonally opposite (in the negative I and positive G quadrant). The remaining quadrants are unoccupied by plausible single-layer responses and may therefore be diagnostic of complex thin-layer reflectivity, and the magnitude and polarity of the C term serves as a further indicator

Testing the standard model with precision calculations of semileptonic B-decays

International Nuclear Information System (INIS)

Turczyk, Sascha S.

2011-01-01

Measurements in the flavour sector are very important to test the Standard Model, since most of the free parameters are related to flavour physics. We are discussing semileptonic B-meson decays, from which an important parameter, vertical stroke V cb vertical stroke, is extracted. First we discuss higher-order non-perturbative corrections in inclusive semileptonic decays of B mesons. We identify the relevant hadronic matrix elements up to 1/m 5 b and estimate them using an approximation scheme. Within this approach the e ects on the integrated rate and on kinematic moments are estimated. Similar estimates are presented for B → X s + γ decays. Furthermore we investigate the role of so-called ''intrinsic-charm'' operators in this decay, which appear first at order 1/m 3 b in the heavy-quark expansion. We show by explicit calculation that - at scales μ ≤ m c - the contributions from ''intrinsic-charm'' effects can be absorbed into short-distance coefficient functions multiplying, for instance, the Darwin term. Then, the only remnant of ''intrinsic charm'' are logarithms of the form ln(m 2 c /m 2 b ), which can be resummed by using renormalization-group techniques. As long as the dynamics at the charm quark scale is perturbative, α s (m c ) 3 b . However, ''intrinsic charm'' leads at the next order to terms with inverse powers of the charm mass: 1/m 3 b x 1/m 2 c . Parametrically they complement the estimate of the potential impact of 1/m 4 b contributions, which we will explore. In this context, we draw semiquantitative conclusions for the expected scale of weak annihilation in semileptonic B decays, both for its valence and non-valence components. The last part is dedicated to a complementary measurement of vertical stroke V cb vertical stroke from exclusive B → D (*) l anti ν l . Since this determination shows a slight tension with respect to the inclusive one, we investigate wether a non standard model contribution may distort the extraction. (orig.)

Evaluation of the separation and purification of 227Th from its decay progeny by anion exchange and extraction chromatography

International Nuclear Information System (INIS)

Ivanov, P.I.; Collins, S.M.; Es, E.M. van; García-Miranda, M.; Jerome, S.M.; Russell, B.C.

2017-01-01

Thorium-227 is currently undergoing evaluation as a potential radionuclide for targeted cancer therapy, and as such a high chemical purity of the material is required. To establish a reliable procedure for radiochemical isolation of 227 Th from the parent 227 Ac and decay progeny, which includes the radiotherapeutic 223 Ra, the performance of three different separation schemes based on ion-exchange and extraction chromatography have been evaluated. The results suggest that both ion exchange and extraction chromatographic techniques can be successfully used for the separation of 227 Th from its decay progeny, however extraction chromatographic resins demonstrate favourable performance in terms of Th recovery and purification from radionuclide impurities. - Highlights: • Development of a radiochemical separation of 227 Th from residual 227Ac as well as from decay progeny. • Evaluation of ion-exchange and extraction chromatography techniques. • TEVA resin demonstrates favourable performance in terms of Th recovery and purification. • Developed method is applicable to both nuclear medicine and environmental analysis.

Development of a 3D cell-centered Lagrangian scheme for the numerical modeling of the gas dynamics and hyper-elasticity systems

International Nuclear Information System (INIS)

Georges, Gabriel

2016-01-01

High Energy Density Physics (HEDP) flows are multi-material flows characterized by strong shock waves and large changes in the domain shape due to rare faction waves. Numerical schemes based on the Lagrangian formalism are good candidates to model this kind of flows since the computational grid follows the fluid motion. This provides accurate results around the shocks as well as a natural tracking of multi-material interfaces and free-surfaces. In particular, cell-centered Finite Volume Lagrangian schemes such as GLACE (Godunov-type Lagrangian scheme Conservative for total Energy) and EUCCLHYD (Explicit Unstructured Cell-Centered Lagrangian Hydrodynamics) provide good results on both the modeling of gas dynamics and elastic-plastic equations. The work produced during this PhD thesis is in continuity with the work of Maire and Nkonga [JCP, 2009] for the hydrodynamic part and the work of Kluth and Despres [JCP, 2010] for the hyper elasticity part. More precisely, the aim of this thesis is to develop robust and accurate methods for the 3D extension of the EUCCLHYD scheme with a second-order extension based on MUSCL (Monotonic Upstream-centered Scheme for Conservation Laws) and GRP (Generalized Riemann Problem) procedures. A particular care is taken on the preservation of symmetries and the monotonicity of the solutions. The scheme robustness and accuracy are assessed on numerous Lagrangian test cases for which the 3D extensions are very challenging. (author) [fr

Decays of supernova neutrinos

International Nuclear Information System (INIS)

Lindner, Manfred; Ohlsson, Tommy; Winter, Walter

2002-01-01

Supernova neutrinos could be well-suited for probing neutrino decay, since decay may be observed even for very small decay rates or coupling constants. We will introduce an effective operator framework for the combined description of neutrino decay and neutrino oscillations for supernova neutrinos, which can especially take into account two properties: one is the radially symmetric neutrino flux, allowing a decay product to be re-directed towards the observer even if the parent neutrino had a different original direction of propagation. The other is decoherence because of the long baselines for coherently produced neutrinos. We will demonstrate how to use this effective theory to calculate the time-dependent fluxes at the detector. In addition, we will show the implications of a Majoron-like decay model. As a result, we will demonstrate that for certain parameter values one may observe some effects which could also mimic signals similar to the ones expected from supernova models, making it in general harder to separate neutrino and supernova properties

Rare psi decays

International Nuclear Information System (INIS)

Partridge, R.

1986-01-01

Slightly more than ten years have passed since the psi was discovered, yet the study of psi decays continues to be an active and fruitful area of research. One reason for such longevity is that each successive experiment has increased their sensitivity over previous experiments either by improving detection efficiency or by increasing statistics. This has allowed the observation and, in some cases, detailed studies of rare psi decays. Branching ratios of ≅10-/sup 4/ are now routinely studied, while certain decay channels are beginning to show interesting effects at the 10-/sup 5/ level. Future experiments at the Beijing Electron Positron Collider (BEPC) have the potential for increasing sensitivities by one or two orders of magnitude, thus enabling many interesting studies impossible with current data samples. The author first examines the extent to which psi decays can be used to study electroweak phenomena. The remainder of this work is devoted to the more traditional task of using the psi to study quarks, gluons, and the properties of the strong interaction. Of particular interest is the study of radioactive psi decays, where a number of new particles have been discovered. Recent results regarding two of these particles, the θ(1700) and iota(1450), are discussed, as well as a study of the quark content of the eta and eta' using decays of the psi to vector-pseudoscalar final states

Studying radiative B decays with the Atlas detector; Etude des desintegrations radiatives des mesons B dans le detecteur ATLAS

Energy Technology Data Exchange (ETDEWEB)

Viret, S

2004-09-01

This thesis is dedicated to the study of radiative B decays with the ATLAS detector at the LHC (large hadron collider). Radiative decays belong to the rare decays family. Rare decays transitions involve flavor changing neutral currents (for example b {yields} s{gamma}), which are forbidden at the lowest order in the Standard Model. Therefore these processes occur only at the next order, thus involving penguin or box diagrams, which are very sensitive to 'new physics' contributions. The main goal of our study is to show that it would be possible to develop an online selection strategy for radiative B decays with the ATLAS detector. To this end, we have studied the treatment of low energy photons by the ATLAS electromagnetic calorimeter (ECal). Our analysis shows that ATLAS ECal will be efficient with these particles. This property is extensively used in the next section, where a selection strategy for radiative B decays is proposed. Indeed, we look for a low energy region of interest in the ECal as soon as the level 1 of the trigger. Then, photon identification cuts are performed in this region at level 2. However, a large part of the proposed selection scheme is also based on the inner detector, particularly at level 2. The final results show that large amounts of signal events could be collected in only one year by ATLAS. A preliminary significance (S/{radical}B) estimation is also presented. Encouraging results concerning the observability of exclusive radiative B decays are obtained. (author)

Studying radiative B decays with the Atlas detector; Etude des desintegrations radiatives des mesons B dans le detecteur ATLAS

Energy Technology Data Exchange (ETDEWEB)

Viret, S

2004-09-01

This thesis is dedicated to the study of radiative B decays with the ATLAS detector at the LHC (large hadron collider). Radiative decays belong to the rare decays family. Rare decays transitions involve flavor changing neutral currents (for example b {yields} s{gamma}), which are forbidden at the lowest order in the Standard Model. Therefore these processes occur only at the next order, thus involving penguin or box diagrams, which are very sensitive to 'new physics' contributions. The main goal of our study is to show that it would be possible to develop an online selection strategy for radiative B decays with the ATLAS detector. To this end, we have studied the treatment of low energy photons by the ATLAS electromagnetic calorimeter (ECal). Our analysis shows that ATLAS ECal will be efficient with these particles. This property is extensively used in the next section, where a selection strategy for radiative B decays is proposed. Indeed, we look for a low energy region of interest in the ECal as soon as the level 1 of the trigger. Then, photon identification cuts are performed in this region at level 2. However, a large part of the proposed selection scheme is also based on the inner detector, particularly at level 2. The final results show that large amounts of signal events could be collected in only one year by ATLAS. A preliminary significance (S/{radical}B) estimation is also presented. Encouraging results concerning the observability of exclusive radiative B decays are obtained. (author)

α-decay chains and cluster-decays of superheavy 269-27110 nuclei

International Nuclear Information System (INIS)

Sushil Kumar; Rajesh Kumar; Balasubramaniam, M.; Gupta, Raj K.

2001-01-01

Due to the availability of radioactive nuclear beams (RNB) and the advancement in accelerator technology, it is now possible to synthesize very heavy elements (Z> 100), called superheavy elements. It is a well established fact that these superheavy elements, due to their shorter lifetime, decay via successive alpha emissions and at a later stage undergo spontaneous fission. Several such decay chains are now observed. An attempt is made to fit all such known decay chains and the results of the three observed α-decay chains of Z=110 ( 269-271 10) nuclei are presented. The model used is the preformed cluster model (PCM). Also, an attempt is made for the first time to find the possibility of any branching to heavy-cluster emissions in these chains

SYMPOSIUM: Rare decays

Energy Technology Data Exchange (ETDEWEB)

Anon.

1989-04-15

Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions.

CP violation in B decay

OpenAIRE

Yamamoto, Hitoshi

2001-01-01

We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

Charmless B-decays at LHCb

CERN Document Server

Eklund, Lars

2016-01-01

These proceedings summarise three recent papers from the LHCb Collaboration in the area of charmless b-decays. The branching fraction for the decay $\\text{B}_{s}^{0}\\rightarrow \\phi \\phi$ is measured and a search for the highly suppressed decay $\\text{B}^{0}\\rightarrow \\phi \\phi$ is performed. The decay $\\text{B}_{s}^{0}\\rightarrow {\\eta}'{\\eta}'$ is observed for the first time and the CP asymmetries in the decays $\\text{B}^{+}\\rightarrow {\\eta}'\\text{K}^{+}$ and $\\text{B}^{+}\\rightarrow \\phi \\text{K}^{+}$ are measured. Finally, the decay $\\text{B}^{0}\\rightarrow \\rho^{0}\\rho^{0}$ is observed for the first time and its longitudinal polarisation is measured.

Aspects of B decays

International Nuclear Information System (INIS)

Faller, Sven

2011-01-01

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 → D (*) l anti ν 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 → D (*) l anti ν 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 0 s →J/ψφ and B 0 →J/ψK S,L decays discussing CP violating effects in the time-dependent decay amplitudes by considering new physics phase in the B 0 - anti B 0 mixing phase. (orig.)

Exact analysis of Packet Reversed Packet Combining Scheme and Modified Packet Combining Scheme; and a combined scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2007-07-01

Packet combining scheme is a well defined simple error correction scheme for the detection and correction of errors at the receiver. Although it permits a higher throughput when compared to other basic ARQ protocols, packet combining (PC) scheme fails to correct errors when errors occur in the same bit locations of copies. In a previous work, a scheme known as Packet Reversed Packet Combining (PRPC) Scheme that will correct errors which occur at the same bit location of erroneous copies, was studied however PRPC does not handle a situation where a packet has more than 1 error bit. The Modified Packet Combining (MPC) Scheme that can correct double or higher bit errors was studied elsewhere. Both PRPC and MPC schemes are believed to offer higher throughput in previous studies, however neither adequate investigation nor exact analysis was done to substantiate this claim of higher throughput. In this work, an exact analysis of both PRPC and MPC is carried out and the results reported. A combined protocol (PRPC and MPC) is proposed and the analysis shows that it is capable of offering even higher throughput and better error correction capability at high bit error rate (BER) and larger packet size. (author)

Analytical approximations for the long-term decay behavior of spent fuel and high-level waste

International Nuclear Information System (INIS)

Malbrain, C.M.; Deutch, J.M.; Lester, R.K.

1982-01-01

Simple analytical approximations are presented that describe the radioactivity and radiogenic decay heat behavior of high-level wastes (HLWs) from various nuclear fuel cycles during the first 100,000 years of waste life. The correlations are based on detailed computations of HLW properties carried out with the isotope generation and depletion code ORIGEN 2. The ambiguities encountered in using simple comparisons of the hazards posed by HLWs and naturally occurring mineral deposits to establish the longevity requirements for geologic waste disposal schemes are discussed

Rare B decays at LHCb

CERN Document Server

Puig Navarro, Albert

2017-01-01

Rare decays are flavour changing neutral current processes that allow sensitive searches for phenomena beyond the Standard Model (SM). In the SM, rare decays are loop-suppressed and new particles in SM extensions can give significant contributions. The very rare decay $B^0_s\\to\\mu^+\\mu^-$ in addition helicity suppressed and constitutes a powerful probe for new (pseudo) scalar particles. Of particular interest are furthermore tests of lepton universality in rare $b\\to s\\ell^+\\ell^-$ decays. The LHCb experiment is designed for the study of b-hadron decays and ideally suited for the analysis of rare decays due to its high trigger efficiency, as well as excellent tracking and particle identification performance. Recent results from the LHCb experiment in the area of rare decays are presented, including tests of lepton universality and searches for lepton flavour violation.

MODEL RADIOACTIVE RADON DECAY

Directory of Open Access Journals (Sweden)

R.I. Parovik

2012-06-01

Full Text Available In a model of radioactive decay of radon in the sample (222Rn. The model assumes that the probability of the decay of radon and its half-life depends on the fractal properties of the geological environment. The dependencies of the decay parameters of the fractal dimension of the medium.

Measurement of the initial conversion ratio in AQUILON and EDF 2 reactors

International Nuclear Information System (INIS)

Bergeron, J.; Le Baud, P.; Sautiez, B.

1968-01-01

In natural uranium fuelled reactors, it is important to know the initial conversion ratio, i.e. the ratio of uranium 238 absorption to uranium 235 destruction. The separation of absorption products from fission products is a difficult feature in the measurement of the conversion ratio. A physical method was chosen, the γγ coincidence technique which uses the properties of the decay scheme of neptunium 239 and allows the neptunium activity to be separated from the fission product activity, with some corrections. Detectors of natural uranium are used. The accuracy obtained in the measurements is of the order of 2%. (authors) [fr

Rare and forbidden decays

CERN Document Server

Trampetic, Josip

2002-01-01

In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors, are the second step. Small effects due to the long-distance, spectator contributions, etc. are discussed next. The second section we started with non-leptonic decays, typically $B \\to \\pi\\pi, K\\pi, \\rho\\pi,...$ We describe in more detail our prediction for decays dominated by the $b\\to s \\eta_c$ transition. Reports on the most recent experimental results are given at the end of each subsection. In the second part of the lectures I discuss decays forbidden by the Lorentz and gauge invariance, and due to the violation of the angular moment conservation, generally called the Standard Model-forbiden decays. However, the non-commutative QED and/or non-commutative Standard Model (NCSM), developed in a series of works in the last few years allow some of those decay modes. These ar...

Radioactive decay and labeled compounds

International Nuclear Information System (INIS)

Anon.

1991-01-01

This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

SYMPOSIUM: Rare decays

International Nuclear Information System (INIS)

Anon.

1989-01-01

Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

Sampling the fermi distribution for β-decay energy input to EGS4

International Nuclear Information System (INIS)

Nelson, W.R.; Liu, J.

1992-06-01

A general method is presented for sampling the kinetic energy of electrons emitted during the β-decay process. Two computer codes (BETACDF and BETASAM) have been created to demonstrate and check the sampling scheme. The main purpose of this exercise is to come up with a convenient way to incorporate β-spectra sampling as a front-end to the EGS4 code. This should aid in the solution of a number of problems of current interest, ranging from the design of detectors for experiments in search of 17-keV neutrinos, to establishing a better understanding of the role of β rays in the dosimetry around SLAC beam device

B decays to open charm

CERN Document Server

AUTHOR|(CDS)2073670

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.

Production of the isotope /sup 105/In and investigation of the decay /sup 105/In. -->. /sup 105/Cd

Energy Technology Data Exchange (ETDEWEB)

Rivier, J; Moret, R [Institut des Sciences Nucleaires, 38 - Grenoble (France)

1975-01-01

A new isotope, /sup 105/In, was produced by means of the reaction /sup 106/Cd(p,2n). The half-life of the ground state is 5.1 +- 0.3 min. There is an isomeric level at 674.1 keV (T/sub 1/2/ = 55 +- 5 sec). Thirty-two transitions have been found, and a decay scheme has been set up through a study of the ..gamma.. spectrum and by coincidence techniques.

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.)

Tetrahedral-Mesh Simulation of Turbulent Flows with the Space-Time Conservative Schemes

Science.gov (United States)

Chang, Chau-Lyan; Venkatachari, Balaji; Cheng, Gary C.

2015-01-01

isotropic turbulent flow decay, at a relatively high turbulent Mach number, show a nicely behaved spectral decay rate for medium to high wave numbers. The high-order CESE schemes offer very robust solutions even with the presence of strong shocks or widespread shocklets. The explicit formulation in conjunction with a close to unity theoretical upper Courant number bound has the potential to offer an efficient numerical framework for general compressible turbulent flow simulations with unstructured meshes.

Size of isospin breaking in charged $K_{l4}$ decay

CERN Document Server

Nehme, A

2005-01-01

We evaluate the size of isospin breaking corrections to form factors f and g of the K/sub l4/ decay process K/sup +/ to pi /sup +/ pi /sup -/l/sup +/vl which is actually measured by the extended NA48 setup at CERN. We found that, keeping apart the effect of Coulomb interaction, isospin breaking does not affect the moduli. This is due to the cancellation between corrections of electromagnetic origin and those generated by the difference between up and down quark masses. On the other hand, electromagnetism affects considerably the phases if the infrared divergence is dropped out using a minimal subtraction scheme. Consequently, the greatest care must be taken in the extraction of pi pi phase shifts from experiment.

Nucleon distribution apmlitudes and proton decay matrix elements on the lattice

Energy Technology Data Exchange (ETDEWEB)

Braun, Vladimir M.; Goeckeler, Meinulf [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, Roger [Edinburgh Univ. (GB). School of Physics] (and others)

2008-11-15

Baryon distribution amplitudes (DAs) are crucial for the theory of hard exclusive reactions. We present a calculation of the first few moments of the leading-twist nucleon DA within lattice QCD. In addition we deal with the normalization of the next-to-leading (twist-four) DAs. The matrix elements determining the latter quantities are also responsible for proton decay in Grand Unified Theories. Our lattice evaluation makes use of gauge field configurations generated with two flavors of clover fermions. The relevant operators are renormalized nonperturbatively with the final results given in the MS scheme. We find that the deviation of the leading-twist nucleon DA from its asymptotic form is less pronounced than sometimes claimed in the literature. (orig.)

Strength loss in decayed wood

Science.gov (United States)

Rebecca E. Ibach; Patricia K. Lebow

2014-01-01

Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

Interatomic Coulombic decay following the Auger decay: Experimental evidence in rare-gas dimers

International Nuclear Information System (INIS)

Ueda, K.; Fukuzawa, H.; Liu, X.-J.; Sakai, K.; Pruemper, G.; Morishita, Y.; Saito, N.; Suzuki, I.H.; Nagaya, K.; Iwayama, H.; Yao, M.; Kreidi, K.; Schoeffler, M.; Jahnke, T.; Schoessler, S.; Doerner, R.; Weber, Th.; Harries, J.; Tamenori, Y.

2008-01-01

Interatomic Coulombic decay (ICD) in Ar 2 , ArKr and Kr 2 following Ar 2p or Kr 3d Auger decay has been investigated by means of momentum-resolved electron-ion-ion coincidence spectroscopy. This sequential decay leads to Coulombic dissociation into dication and monocation. Simultaneously determining the kinetic energy of the ICD electron and the kinetic energy release between the two atomic ions, we have been able to unambiguously identify the ICD channels. We find that, in general, spin-conserved ICD, in which the singlet (triplet) dicationic state produced via the atomic Auger decay preferentially decays to the singlet (triplet) state, transferring the energy to the other atom, is faster than spin-flip ICD, in which the Auger final singlet (triplet) dicationic state decays to the triplet (singlet) state. However, spin-flip ICD may take place when spin-conserved ICD becomes energetically forbidden. Dipole-forbidden ICDs from Kr 2+ (4s -21 S)-B (B = Ar or Kr) to Kr 2+ (4p -21 D, 3 P)-B + are also observed

Finite Boltzmann schemes

NARCIS (Netherlands)

Sman, van der R.G.M.

2006-01-01

In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

Radionuclide table. Pt. 1

International Nuclear Information System (INIS)

Legrand, Jean; Perolat, J.-P.; Lagoutine, Frederic; Le Gallic, Yves.

The evaluation of the following 29 radionuclides is presented: 22 Na, 24 Na, sup(24m)Na, 51 Cr, 54 Mn, 57 Co, 58 Co, sup(58m)Co, 60 Co, sup(60m)Co, 75 Se, 103 Ru, sup(103m)Rh, sup(110m)Ag- 110 Ag, 109 Cd, 125 Sb, sup(125mTe), 125 I, 133 Xe, sup(133m)Xe, 131 Cs, 134 Cs, sup(134m)Cs, 139 Ce, 144 Ce- 144 Pr, 144 Pr, 169 Er, 186 Re, 203 Hg. The introduction contains a brief description of radioactive processes and the evaluation rules followed. The best values and associated uncertainties are given for each radionuclide for the major parameters of the decay scheme and the radiation intensities emitted, together with a decay table. Gamma, X-rays and sometimes conversion electron spectra are also provided [fr

Stabilized linear semi-implicit schemes for the nonlocal Cahn-Hilliard equation

Science.gov (United States)

Du, Qiang; Ju, Lili; Li, Xiao; Qiao, Zhonghua

2018-06-01

Comparing with the well-known classic Cahn-Hilliard equation, the nonlocal Cahn-Hilliard equation is equipped with a nonlocal diffusion operator and can describe more practical phenomena for modeling phase transitions of microstructures in materials. On the other hand, it evidently brings more computational costs in numerical simulations, thus efficient and accurate time integration schemes are highly desired. In this paper, we propose two energy-stable linear semi-implicit methods with first and second order temporal accuracies respectively for solving the nonlocal Cahn-Hilliard equation. The temporal discretization is done by using the stabilization technique with the nonlocal diffusion term treated implicitly, while the spatial discretization is carried out by the Fourier collocation method with FFT-based fast implementations. The energy stabilities are rigorously established for both methods in the fully discrete sense. Numerical experiments are conducted for a typical case involving Gaussian kernels. We test the temporal convergence rates of the proposed schemes and make a comparison of the nonlocal phase transition process with the corresponding local one. In addition, long-time simulations of the coarsening dynamics are also performed to predict the power law of the energy decay.

To decay or not to decay - or both ! quantum mechanics of spontaneous emission

DEFF Research Database (Denmark)

Kristensen, Philip Trøst; Lodahl, Peter; Mørk, Jesper

2008-01-01

We discuss calculations of spontaneous emission from quantum dots in photonic crystals and show how the decay depends on the intrinsic properties of the emitter as well as the position. A number of fundamentally different types of spontaneous decay dynamics are shown to be possible, including...... counter intuitive situations in which the quantum dot decays only partially....

Axigluon decays of toponium

International Nuclear Information System (INIS)

Faustov, R.N.; Vasilevskaya, I.G.

1990-01-01

Chiral-colour model predicts the existence of axigluons which is an octet of massive axial-vector gauge bosons. In this respect toponium decays into axigluons and gluons are of interest. The following toponium decays are considered: θ → Ag, θ → AAg, θ → ggg → AAg. The width of toponium S-state decays is calculated under various possible values of axigluon mass

Half-life determination of T{sub z} = -1 and T{sub z} = -(1)/(2) proton-rich nuclei and the β decay of {sup 58}Zn

Energy Technology Data Exchange (ETDEWEB)

Kucuk, L.; Oktem, Y.; Cakirli, R.B.; Ganioglu, E.; Susoy, G. [Istanbul University, Department of Physics, Istanbul (Turkey); Orrigo, S.E.A.; Montaner-Piza, A.; Rubio, B. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Fujita, Y. [Osaka University, Department of Physics, Toyonaka, Osaka (Japan); Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka (Japan); Gelletly, W. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); University of Surrey, Department of Physics, Guildford, Surrey (United Kingdom); Blank, B.; Ascher, P.; Giovinazzo, J.; Grevy, S. [Centre d' Etudes Nucleaires de Bordeaux Gradignan, CNRS/IN2P3 - Universite de Bordeaux, Gradignan (France); Adachi, T.; Fujita, H.; Tamii, A. [Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka (Japan); Algora, A. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Inst. of Nuclear Research of the Hung. Acad. of Sciences, Debrecen (Hungary); France, G. de; Oliveira Santos, F. de; Thomas, J.C. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); Marques, F.M. [Laboratoire de Physique Corpusculaire de Caen, ENSICAEN, UNICAEN, IN2P3/CNRS, Caen (France); Molina, F. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Comision Chilena de Energia Nuclear, Casilla 188-D, Santiago (Chile); Perrot, L. [IPN Orsay, Orsay (France); Raabe, R. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Srivastava, P.C. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Caen (France); Indian Institute of Technology, Department of Physics, Roorkee (India)

2017-06-15

We have measured the β-decay half-lives of 16 neutron-deficient nuclei with T{sub z} = -1/2 and -1, ranging from chromium to germanium. They were produced in an experiment carried out at GANIL and optimized for the production of {sup 58}Zn, for which in addition we present the decay scheme and absolute Fermi and Gamow-Teller transition strengths. Since all of these nuclei lie on the rp-process pathway, the T{sub 1/2} values are important ingredients for the rp-process reaction flow calculations and for models of X-ray bursters. (orig.)

NEPTUNE: a modular scheme for the calculation of light water reactors

International Nuclear Information System (INIS)

Kavenoky, A.

1975-01-01

The NEPTUNE modular scheme has been developed to provide the physicist and the design engineer with a single system of codes for the calculation of light water reactors. The APOLLO code is included in NEPTUNE for the multigroup transport treatment of cells, groups of cells and complete fuel assemblies; few groups cross section libraries are automatically transmitted to the reactor multidimensional diffusion modules. In the reactor phase, 1D and 2D diffusion calculations can be performed by use of the finite difference method; 2D and 3D calculations are done respectively by the BILAN and TRIDENT modules using the finite element method. For the depletion calculation coarse and refined computations are offered. NEPTUNE is characterized by two special features for the data processing: the OTOMAT system which provides a virtual memory simulation and the intervention Monitor which allow to disconnect the computation modules and the control modules [fr

RADIATIVE PENGUIN DECAYS FROM BABAR

Energy Technology Data Exchange (ETDEWEB)

Eigen, Gerald

2003-08-28

Electroweak penguin decays provide a promising hunting ground for Physics beyond the Standard Model (SM). The decay B {yields} X{sub s}{gamma}, which proceeds through an electromagnetic penguin loop, already provides stringent constraints on the supersymmetric (SUSY) parameter space. The present data samples of {approx}1 x 10{sup 8} B{bar B} events allow to explore radiative penguin decays with branching fractions of the order of 10{sup -6} or less. In this brief report they discuss a study of B {yields} K*{ell}{sup +}{ell}{sup -} decay modes and a search for B {yields} {rho}({omega}){gamma} decays.

Charmless Hadronic Beauty Decays at LHCb

Directory of Open Access Journals (Sweden)

Williams Timothy

2017-01-01

Full Text Available A summary of six LHCb results on the topic of charmless hadronic b-hadron decays is presented. These are comprised of: a search for the decay Bs0→Ks0K+K− and updated branching fraction measurements of B(s0→Ks0h+h′− decays (h=K,π [1]; the first observation of the decays B0→pp¯π+π−,  Bs0→pp¯K+K−,Bs0→pp¯K+π− and strong evidence for the decay B0→pp¯K+K− [2]; the first observation of the decay Bs0→pΛ¯K− [3]; a search for the decay Bs0→φη′ [4]; the first observation of the decay Ξb−→pK−K− [5] and evidence for CP-violation in Λb0→pπ−π+π− decays [6].

Measurement of the proton asymmetry (C) in free neutron β-decay with Perkeo III

Energy Technology Data Exchange (ETDEWEB)

Raffelt, Lukas Michael

2016-10-19

The decay of polarized neutrons can be used to search for Physics Beyond the Standard Model. The non-isotropic angular distributions of the decay particles are parity violating and reveal the true nature of the weak interaction. Many observables are available in the decay of polarized neutrons, but the decay itself is only described by three parameters, which allows searches for new physics in a combined analysis. Measurements of the electron angular correlation coefficient (A) can be used to precisely determine the ratio of the axial to the vector coupling constant. The proton angular correlation coefficient (C) has only been measured once by a predecessor of this experiment. We measured the proton asymmetry with a similar proton detector, but employed a new measuring scheme allowing the collection of the worlds first data on the proton energy dependence of the proton asymmetry. At the current state of the analysis, a statistical uncertainty on the value of C of 0.8 % in each of the two detectors can be reached. For a final value, studies of systematic effects based on field simulations and tracking are still missing. For this measurement I designed and constructed a new detector. For the first time the scintillator was coated with a transparent conductive coating and together with the new CAD milled light-guides in a four-side readout configuration the low energy performance of the detector could be increased. Several systematic effects have been studied, especially the Point Spread Function of the magnetic transport system.

JNDC FP decay data file

International Nuclear Information System (INIS)

Yamamoto, Tohru; Akiyama, Masatsugu

1981-02-01

The decay data file for fission product nuclides (FP DECAY DATA FILE) has been prepared for summation calculation of the decay heat of fission products. The average energies released in β- and γ-transitions have been calculated with computer code PROFP. The calculated results and necessary information have been arranged in tabular form together with the estimated results for 470 nuclides of which decay data are not available experimentally. (author)

Prompt neutrinos from atmospheric charm in the general-mass variable-flavor-number scheme

International Nuclear Information System (INIS)

Benzke, M.; Garzelli, M.V.; Kniehl, B.A.; Kramer, G.; Moch, S.; Sigl, G.

2017-08-01

We present predictions for the prompt-neutrino flux arising from the decay of charmed mesons and baryons produced by the interactions of high-energy cosmic rays in the Earth's atmosphere, making use of a QCD approach on the basis of the general-mass variable-flavor-number scheme for the description of charm hadroproduction at NLO, complemented by a consistent set of fragmentation functions. We compare the theoretical results to those already obtained by our and other groups with different theoretical approaches. We provide comparisons with the experimental results obtained by the IceCube Collaboration in two different analyses and we discuss the implications for parton distribution functions.

Exclusive semileptonic B-meson decays

International Nuclear Information System (INIS)

Hagiwara, K.; Martin, A.D.; Wade, M.F.

1989-01-01

We study the semileptonic processes anti B → D * lanti ν and anti B → Dlanti ν and show that the invariant hadronic form factors describing the decays can be measured directly by observing the angular correlations of the decay products. We emphasize that this allows an almost model-independent determination of the V cb quark mixing-matrix element. We examine the theoretical models for the form factors in terms of the spectator quark approach. We present a general formalism for semileptonic decays which includes lepton mass effects, since the decay into τ-leptons may be important as background events in the search for rare decay modes involving missing particles. (orig.)

Shannon entropy and particle decays

Science.gov (United States)

Carrasco Millán, Pedro; García-Ferrero, M. Ángeles; Llanes-Estrada, Felipe J.; Porras Riojano, Ana; Sánchez García, Esteban M.

2018-05-01

We deploy Shannon's information entropy to the distribution of branching fractions in a particle decay. This serves to quantify how important a given new reported decay channel is, from the point of view of the information that it adds to the already known ones. Because the entropy is additive, one can subdivide the set of channels and discuss, for example, how much information the discovery of a new decay branching would add; or subdivide the decay distribution down to the level of individual quantum states (which can be quickly counted by the phase space). We illustrate the concept with some examples of experimentally known particle decay distributions.

Ultra-Rare B Decays

International Nuclear Information System (INIS)

Grinstein, Benjamin

2004-01-01

A good place to look for deviations from the Standard Model is in decay modes of B mesons, like purely leptonic decays B → lv, for which a very long Standard Model lifetime is due to an accidental suppression of the decay amplitude. For other rare decay modes involving no hadrons in the final state (e.g., B → γl+l-, B → γlvl and B → vv-barγ) new results on QCD factorization in exclusive processes show that all the decay rates are given in terms of a single universal form factor. Hence, trustworthy relations between different processes can be used to test the Standard Model of electroweak interactions. Sometimes, surprisingly, a large energy expansion may allow computation when a hadron is in the final state. An example is B → πl+l- which can be used to settle the ambiguity in α from a measurement of sin2α from CP asymmetries

Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

Science.gov (United States)

Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

2012-04-01

The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

International Nuclear Information System (INIS)

Rajput, M.U.; Ali, N.; Hussain, S.; Mujahid, S.A.; MacMahon, D.

2012-01-01

The radionuclide 125 Sb is a long-lived fission product, which decays to 125 Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125 Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125 Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125 Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

Visible neutrino decay at DUNE

Energy Technology Data Exchange (ETDEWEB)

Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

2017-05-09

If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

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.)

Inflaton decay in supergravity

International Nuclear Information System (INIS)

Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.

2007-06-01

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) C gauge interactions. (orig.)

Decay of mass-separated 3.0min 195gBi to levels in 195Pb and shape coexistence in the neutron-deficient odd-mass Pb isotopes

International Nuclear Information System (INIS)

Griffin, J.C.; Braga, R.A.; Fink, R.W.; Bingham, C.R.; Coenen, E.; Huyse, M.; Duppen, P. van

1991-01-01

The radioactive decay of mass-separated 3.0 m 195g Bi to 195 Pb has been studied with the UNISOR and LISOL facilities. Time-sequenced spectra of γ-rays, X-rays, and conversion electrons have been obtained, together with γγt, γXt, eγt, and eXt coincidence data. From this information, a decay scheme has been constructed consisting of 23 excited states and 34 transitions in 195 Pb. Transitions with E0 multipole admixtures, indicative of shape coexistence, have been found to de-excite positive-parity levels at 1093, 1329, and 1380 keV. The beta-decay energy of the 195 Bi ground state is deduced to be Q EC =4800 +600 -550 keV based on the measurement of γ-ray-gated K/β + ratios. The excitation energy of the i 13/2 isomer in 195 Pb has been determined to be 203±4 keV from the α-decays of 199m,g Po. (orig.)

β-delayed p-decay of proton-rich nuclei ^23Al and ^31Cl and explosive H-burning in novae

Science.gov (United States)

Trache, L.; Banu, A.; Hardy, J. C.; McCleskey, M.; Simmons, E.; Tabacaru, G.; Tribble, R. E.; Aysto, J.; Jokinen, A.; Saastamoinen, A.; Davinson, T.; Woods, P. J.; Achouri, L.; Roeder, B.

2008-10-01

We developed a technique to measure β-delayed proton-decay of proton-rich nuclei produced and separated with MARS at TAMU. In particular, we studied the decay of ^23Al and ^31Cl, both important for understanding explosive H-burning in novae. We have pulsed the beam, implanting the source nuclei moving at about 40 MeV/u in a thin Si strip detector, and then measured β-p and β-γ coincidences simultaneously. The states populated above the proton threshold in ^23Mg and ^31S, respectively, may proton decay. They are resonances in the reaction ^22Na(p,γ)^23Mg (crucial for the depletion of ^22Na in ONe novae) and in ^30P(p,γ)^31S (critical point in explosive H-burning in novae), but the protons emitted have very low energies, starting at about 200 keV, an experimental challenge. The setup and the results are described. The β-decay schemes were established for both nuclei, and IAS identified. The technique has shown a remarkable selectivity to β-delayed charged particle emission and shown to work even at radioactive beam rates of a few pps, for rare isotopes with lifetimes as low as 10s msec.

The π+ Decay of Light Hypernuclei

International Nuclear Information System (INIS)

Gibson, B.F.

1999-01-01

The observed π + emission from the weak decay of the 4 Λ He hypernucleus has been an intriguing puzzle for more than 30 years, because the Lambda decays in free space only by emission of a π - or a π 0 . We re-examine this puzzling weak decay with our focus upon a decay mechanism involving the Σ + N r a rrow π + nN decay of a virtual Σ + , stemming from ΛN to ΣN conversion (mixing) within the hypernucleus. We emphasize the observed energy distribution of the observed π + s compared to that of π - s in standard mesonic decay as well as the isotropic angular distribution of the π + s. Competing suggestions to explain the positive pion weak decay have been offered. A possible search for π + decay from the other Λ hypernuclei is explored as means to test our hypothesis

Search for new mechanism of CP violation through tau decay and semileptonic decay at hadrons

International Nuclear Information System (INIS)

Tsai, Yung Su.

1996-11-01

If CP is violated in any decay process involving leptons it will signify the existence of a new force (called the X boson) responsible for CP violation that may be the key to understanding matter-antimatter asymmetry in the universe. The author discusses the signatures of CP violation in (1) the decay of tau lepton, and (2) the semileptonic decay of π, K, D, B and t particles by measuring the polarization of the charged lepton in the decay. The author discusses how the coupling constants and their phases of the coupling of the X boson to 9 quark vertices and 3 lepton vertices can be obtained through 12 decay processes

Decay constants and radiative decays of heavy mesons in light-front quark model

International Nuclear Information System (INIS)

Choi, Ho-Meoyng

2007-01-01

We investigate the magnetic dipole decays V→Pγ of various heavy-flavored mesons such as (D,D*,D s ,D s *,η c ,J/ψ) and (B,B*,B s ,B s *,η b ,Υ) using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors F VP (q 2 ) for V→Pγ* decays are obtained in the q + =0 frame and then analytically continued to the timelike region by changing q perpendicular to iq perpendicular in the form factors. The coupling constant g VPγ for real photon case is then obtained in the limit as q 2 →0, i.e. g VPγ =F VP (q 2 =0). The weak decay constants of heavy pseudoscalar and vector mesons are also calculated. Our numerical results for the decay constants and radiative decay widths for the heavy-flavored mesons are overall in good agreement with the available experimental data as well as other theoretical model calculations

Sigma beta decay

International Nuclear Information System (INIS)

Newman, D.E.

1975-01-01

Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

Charmless decays of the B-meson in perturbative QCD

International Nuclear Information System (INIS)

Libo Guo; Dongsheng Du; Lianshou Liu

1999-01-01

Using the perturbative QCD method and Chau's six-quark-graph scheme, we report a theoretical calculation of exclusive nonleptonic decays of the B meson into two light pseudoscalar mesons in the context of the low-energy effective Hamiltonian. The contributions from both tree-level and one-loop diagrams are taken into account. Under the approximation of neglecting light quark and light meson masses, we find that (i) within perturbative QCD there is no singularity which exists in the computation of spacelike penguin diagrams when the BSW model is used; (ii) the contributions from spacelike-type (W-annihilation, W-exchange, spacelike penguin and penguin-annihilation) graphs are strongly suppressed relative to those from timelike-type (external W-emission, internal W-emission and timelike penguin) ones; (iii) our results are well below the experimental upper limits but lower than the BSW ones. (author)

β-delayed charged particle decays of neutron-deficient nuclei 20Mg and 23Si and 22Si

International Nuclear Information System (INIS)

Babo, Mathieu

2016-01-01

The neutron-deficient nuclei 20 Mg, 23 Si and 22 Si were produced by fragmentation at NSCL, at MSU (USA), and implanted into an array of 3 double sided stripped Si detectors, surrounded by 16 high-purity Ge detectors. This novel arrangement allowed the detection of the charged particles emitted by the unbound excited states in coincidence with the γ rays emitted by the de-excitation of the daughter. The βp decay of 20 Mg is very well-known and therefore was used to test and optimize the analysis program. The β-delayed proton transitions to the first 3 excited states in 19 Ne were identified and compared to previous measurements. The half-life, the branching ratio of the transitions and the excitation energies, including the IAS, were measured and are in good agreement with the adopted values. The study of the β+ decay of 23 Si allowed the identification of 14 excited states in 23 Al. The emission of 2 protons from the IAS was unambiguously identified. The measurement of the IAS energy allowed a better determination of the mass excess of 23 Si, giving 23.27 (7) MeV. A possible β3p decay channel was also tentatively identified. Most of the theoretical predictions are in favor of a 2-proton radioactive 22 Si. The β2p decays to the first excited state and the ground state of 20 Na were identified. The branching ratio of the decay to the IAS is 2.05 (44) %, and the IAS excitation energy was measured to be 9040 (54) keV. The additional measurement of the half-life gives T 1/2 = 30.38 (45) ms, and allowed the determination of the partial half-life. In this study, we propose a parameterization of the statistical rate function f for the superallowed Fermi β decays. This allow the first indirect mass measurement of 22 Si ground state, 31.49 (14) MeV. The two-proton threshold is then S2p = 645 (100) keV and does not allow 2p radioactivity. (author) [fr

Iconic decay in schizophrenia.

Science.gov (United States)

Hahn, Britta; Kappenman, Emily S; Robinson, Benjamin M; Fuller, Rebecca L; Luck, Steven J; Gold, James M

2011-09-01

Working memory impairment is considered a core deficit in schizophrenia, but the precise nature of this deficit has not been determined. Multiple lines of evidence implicate deficits at the encoding stage. During encoding, information is held in a precategorical sensory store termed iconic memory, a literal image of the stimulus with high capacity but rapid decay. Pathologically increased iconic decay could reduce the number of items that can be transferred into working memory before the information is lost and could thus contribute to the working memory deficit seen in the illness. The current study used a partial report procedure to test the hypothesis that patients with schizophrenia (n = 37) display faster iconic memory decay than matched healthy control participants (n = 28). Six letters, arranged in a circle, were presented for 50 ms. Following a variable delay of 0-1000 ms, a central arrow cue indicated the item to be reported. In both patients and control subjects, recall accuracy decreased with increasing cue delay, reflecting decay of the iconic representation of the stimulus array. Patients displayed impaired memory performance across all cue delays, consistent with an impairment in working memory, but the rate of iconic memory decay did not differ between patients and controls. This provides clear evidence against faster loss of iconic memory representations in schizophrenia, ruling out iconic decay as an underlying source of the working memory impairment in this population. Thus, iconic decay rate can be added to a growing list of unimpaired cognitive building blocks in schizophrenia.

Particle decay in inflationary cosmology

International Nuclear Information System (INIS)

Boyanovsky, D.; Vega, H.J. de

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. For superhorizon modes we find that the decay is of the form η Γ 1 with η being conformal time and we give an explicit expression for Γ 1 to leading order in the coupling which has a noteworthy interpretation in terms of the Hawking temperature of de Sitter space-time. We show that if the mass M of the decaying field is << H then the decay rate during inflation is enhanced over the Minkowski space-time result by a factor 2H/πM. For wavelengths much smaller than the Hubble radius we find that the decay law is e with C(η) the scale factor and α determined by the strength of the trilinear coupling. In all cases we find a substantial enhancement in the decay law as compared to Minkowski space-time. These results suggest potential implications for the spectrum of scalar density fluctuations as well as non-Gaussianities

Radical Abstraction Reactions with Concerted Fragmentation in the Chain Decay of Nitroalkanes

Science.gov (United States)

Denisov, E. T.; Shestakov, A. F.

2018-05-01

Reactions of the type X• + HCR2CH2NO2 → XH + R2C=CH2 + N•O2 are exothermic, due to the breaking of weak C-N bonds and the formation of energy-intensive C=C bonds. Quantum chemistry calculations of the transition state using the reactions of Et• and EtO• with 2-nitrobutane shows that such reactions can be categorized as one-step, due to the extreme instability of the intermediate nitrobutyl radical toward decay with the formation of N•O2. Kinetic parameters that allow us to calculate the energy of activation and rate constant of such a reaction from its enthalpy are estimated using a model of intersecting parabolas. Enthalpies, energies of activation, and rate constants are calculated for a series of reactions with the participation of Et•, EtO•, RO•2, N•O2 radicals on the one hand and a series of nitroalkanes on the other. A new kinetic scheme of the chain decay of nitroalkanes with the participation of abstraction reactions with concerted fragmentation is proposed on the basis of the obtained data.

Three-body decays: structure, decay mechanism and fragment properties

International Nuclear Information System (INIS)

Alvarez-Rodriguez, R.; Jensen, A.S.; Fedorov, D.V.; Fynbo, H.O.U.; Kirsebom, O.S.; Garrido, E.

2009-01-01

We discuss the three-body decay mechanisms of many-body resonances. R-matrix sequential description is compared with full Faddeev computation. The role of the angular momentum and boson symmetries is also studied. As an illustration we show the computed ?-particle energy distribution after the decay of 12 C(1 + ) resonance at 12.7 MeV. This article is based on the presentation by R. Alvarez-Rodriguez at the Fifth Workshop on Critical Stability, Erice, Sicily. (author)

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

Is Radioactive Decay Really Exponential?

OpenAIRE

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 ...

Study of {sup 193}Os beta{sup -} decay; Estudo do decaimento beta{sup -} do {sup 193}Os

Energy Technology Data Exchange (ETDEWEB)

Zahn, Guilherme Soares

2006-07-01

In this work, the excited levels of {sup 193}Ir populated by the beta{sup -} decay of {sup 193}Os (T{sub 1/2} {approx} 30h) were investigated. For that purpose, {approx} 5 mg samples of 99%-enriched {sup 192}Os were irradiated under a thermal neutron flux of {approx} 10{sup 12} s{sup -1} and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma ({theta} ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2{sup +;} moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio ({delta}{sub Ln+1}/L{sub n}) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in {sup 193}Ir. (author)

CP-violations in B decays

Indian Academy of Sciences (India)

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 ...

Investigation of the 168Hf electron capture decay using fast radiochemical separation

International Nuclear Information System (INIS)

Trubert, D.; Hussonnois, M.; Brillard, L.; Barci, V.; Ardisson, G.; Szeglowski, Z.; Constantinescu, O.

1995-01-01

The (EC + β + ) decay of 168 Hf, produced by the 156 Gd ( 16 O,4n) reaction, has been studied, with high efficiency HPGe coaxial detectors, using on-line measurements carried out with the RACHEL setup, built to investigate the chemical properties of transactinide elements. Off-line measurements were also carried out using catcher collection technique. Energies and intensities of 119 γ-lines are reported among which only two were known in the earlier study of Chu and Reednick. The 168 Lu level scheme built on the basis of single and γ-γ coincidence measurements, allows the interpretation of more than 79 γ-transitions, between 38 excited states reported for the first time. (orig.)

Adaptive protection scheme

Directory of Open Access Journals (Sweden)

R. Sitharthan

2016-09-01

Full Text Available This paper aims at modelling an electronically coupled distributed energy resource with an adaptive protection scheme. The electronically coupled distributed energy resource is a microgrid framework formed by coupling the renewable energy source electronically. Further, the proposed adaptive protection scheme provides a suitable protection to the microgrid for various fault conditions irrespective of the operating mode of the microgrid: namely, grid connected mode and islanded mode. The outstanding aspect of the developed adaptive protection scheme is that it monitors the microgrid and instantly updates relay fault current according to the variations that occur in the system. The proposed adaptive protection scheme also employs auto reclosures, through which the proposed adaptive protection scheme recovers faster from the fault and thereby increases the consistency of the microgrid. The effectiveness of the proposed adaptive protection is studied through the time domain simulations carried out in the PSCAD⧹EMTDC software environment.

Study and conception of the decay ring of a neutrino facility using the β decays of the helium 6 and neon 18 nuclei produced by an intense beam of protons hitting various targets

International Nuclear Information System (INIS)

Chance, A.

2007-09-01

The study of the neutrino oscillation between its different flavours needs pure and very intense flux of energetic, well collimated neutrinos with a well determined energy spectrum. So, a dedicated machine seems necessary nowadays. Among the different concepts of neutrino facilities, the one which will be studied here, called Beta-Beams, lies on the neutrino production by beta decay of radioactive ions after their acceleration. More precisely, the thesis is focused on the study and the design of the race-track-shaped storage ring of the high energy ions. Its aim is to store the ions until decaying. After a brief description of the neutrino oscillation mechanism and a review of the different experiments, an introduction to the neutrino facility concept and more precisely to the Beta-Beams will be given. Then, the issues linked to the Beta-Beams will be presented. After a description of the beam transport formalism, a first design and the optical properties of the ring will be then given. The effects of the misalignment and of the field errors in the dipoles have been studied. The dynamic aperture optimization is then realized. Handling of the decay losses or the energy collimation scheme will be developed. The off-momentum injection needed in presence of a circulating beam will be explained. Finally, the specific radiofrequency program needed by the beam merging will be presented. (author)

Comparative study of numerical schemes of TVD3, UNO3-ACM and optimized compact scheme

Science.gov (United States)

Lee, Duck-Joo; Hwang, Chang-Jeon; Ko, Duck-Kon; Kim, Jae-Wook

1995-01-01

Three different schemes are employed to solve the benchmark problem. The first one is a conventional TVD-MUSCL (Monotone Upwind Schemes for Conservation Laws) scheme. The second scheme is a UNO3-ACM (Uniformly Non-Oscillatory Artificial Compression Method) scheme. The third scheme is an optimized compact finite difference scheme modified by us: the 4th order Runge Kutta time stepping, the 4th order pentadiagonal compact spatial discretization with the maximum resolution characteristics. The problems of category 1 are solved by using the second (UNO3-ACM) and third (Optimized Compact) schemes. The problems of category 2 are solved by using the first (TVD3) and second (UNO3-ACM) schemes. The problem of category 5 is solved by using the first (TVD3) scheme. It can be concluded from the present calculations that the Optimized Compact scheme and the UN03-ACM show good resolutions for category 1 and category 2 respectively.

Beta Decay Study of the T{sub z}=−2{sup 56}Zn Nucleus and the Determination of the Half-Lives of a Few fp-shell Nuclei

Energy Technology Data Exchange (ETDEWEB)

Rubio, B., E-mail: Berta.Rubio@ific.uv.es [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Orrigo, S.E.A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Kucuk, L. [Department of Physics, Istanbul University, Istanbul (Turkey); Montaner-Pizá, A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Fujita, Y. [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); RCNP, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Fujita, H. [RCNP, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Blank, B. [CENBG, Université Bordeaux 1, UMR 5797 CNRS/IN2P3, BP 120, F-33175 Gradignan (France); Gelletly, W. [Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey (United Kingdom); Adachi, T. [RCNP, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Agramunt, J.; Algora, A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Ascher, P. [CENBG, Université Bordeaux 1, UMR 5797 CNRS/IN2P3, BP 120, F-33175 Gradignan (France); Bilgier, B. [Department of Physics, Istanbul University, Istanbul (Turkey); Cáceres, L. [GANIL, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen (France); Cakirli, R.B. [Department of Physics, Istanbul University, Istanbul (Turkey); France, G. de [GANIL, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen (France); Ganioğlu, E. [Department of Physics, Istanbul University, Istanbul (Turkey); Gerbaux, M.; Giovinazzo, J.; Grevy, S. [CENBG, Université Bordeaux 1, UMR 5797 CNRS/IN2P3, BP 120, F-33175 Gradignan (France); and others

2014-06-15

This paper concerns the experimental study of the β decay properties of few proton-rich fp-shell nuclei. The nuclei were produced at GANIL in fragmentation reactions, separated with the LISE spectrometer and stopped in an implantation detector surrounded by Ge detectors. The β-delayed gammas, β-delayed protons and the exotic β-delayed gamma-proton emission have been studied. Preliminary results are presented. The decay of the T{sub z}=−2 nucleus {sup 56}Zn has been studied in detail. Information from the β-delayed protons and β-delayed gammas has been used to deduce the decay scheme. The exotic beta-delayed gamma-proton decay has been observed for the first time in the fp-shell. The interpretation of the data was made possible thanks to the detailed knowledge of the mirror Charge Exchange (CE) process and the gamma de-excitation of the states in {sup 56}Co, the mirror nucleus of {sup 56}Cu.

B decays

CERN Document Server

Stone, Sheldon

1994-01-01

This book reviews the study of b quarks and also looks at the implications of future studies. The most important observations thus far - including measurement of the ""B"" lifetime and observations of b -> u transitions - as well as the more mundane results of 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. Synthesizing the experimental and theoretical information, the authors d

A Stable Marching on-in-time Scheme for Solving the Time Domain Electric Field Volume Integral Equation on High-contrast Scatterers

KAUST Repository

Sayed, Sadeed Bin

2015-05-05

A time domain electric field volume integral equation (TD-EFVIE) solver is proposed for characterizing transient electromagnetic wave interactions on high-contrast dielectric scatterers. The TD-EFVIE is discretized using the Schaubert- Wilton-Glisson (SWG) and approximate prolate spherical wave (APSW) functions in space and time, respectively. The resulting system of equations can not be solved by a straightforward application of the marching on-in-time (MOT) scheme since the two-sided APSW interpolation functions require the knowledge of unknown “future” field samples during time marching. Causality of the MOT scheme is restored using an extrapolation technique that predicts the future samples from known “past” ones. Unlike the extrapolation techniques developed for MOT schemes that are used in solving time domain surface integral equations, this scheme trains the extrapolation coefficients using samples of exponentials with exponents on the complex frequency plane. This increases the stability of the MOT-TD-EFVIE solver significantly, since the temporal behavior of decaying and oscillating electromagnetic modes induced inside the scatterers is very accurately taken into account by this new extrapolation scheme. Numerical results demonstrate that the proposed MOT solver maintains its stability even when applied to analyzing wave interactions on high-contrast scatterers.

A Stable Marching on-in-time Scheme for Solving the Time Domain Electric Field Volume Integral Equation on High-contrast Scatterers

KAUST Repository

Sayed, Sadeed Bin; Ulku, Huseyin; Bagci, Hakan

2015-01-01

A time domain electric field volume integral equation (TD-EFVIE) solver is proposed for characterizing transient electromagnetic wave interactions on high-contrast dielectric scatterers. The TD-EFVIE is discretized using the Schaubert- Wilton-Glisson (SWG) and approximate prolate spherical wave (APSW) functions in space and time, respectively. The resulting system of equations can not be solved by a straightforward application of the marching on-in-time (MOT) scheme since the two-sided APSW interpolation functions require the knowledge of unknown “future” field samples during time marching. Causality of the MOT scheme is restored using an extrapolation technique that predicts the future samples from known “past” ones. Unlike the extrapolation techniques developed for MOT schemes that are used in solving time domain surface integral equations, this scheme trains the extrapolation coefficients using samples of exponentials with exponents on the complex frequency plane. This increases the stability of the MOT-TD-EFVIE solver significantly, since the temporal behavior of decaying and oscillating electromagnetic modes induced inside the scatterers is very accurately taken into account by this new extrapolation scheme. Numerical results demonstrate that the proposed MOT solver maintains its stability even when applied to analyzing wave interactions on high-contrast scatterers.

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.)

Effective Majorana neutrino decay

Energy Technology Data Exchange (ETDEWEB)

Duarte, Lucia [Instituto de Fisica, Facultad de Ingenieria,Universidad de la Republica, Montevideo (Uruguay); Romero, Ismael; Peressutti, Javier; Sampayo, Oscar A. [Universidad Nacional de Mar del Plata, Departamento de Fisica, Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR) CONICET, UNMDP, Mar del Plata (Argentina)

2016-08-15

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 these 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. (orig.)

Statistical decay of giant resonances

International Nuclear Information System (INIS)

Dias, H.; Teruya, N.; Wolynec, E.

1986-01-01

Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the resutls on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monople giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excelent agreement with recent experimental data, showing that the decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

Statistical decay of giant resonances

International Nuclear Information System (INIS)

Dias, H.; Teruya, N.; Wolynec, E.

1986-02-01

Statistical calculations to predict the neutron spectrum resulting from the decay of Giant Resonances are discussed. The dependence of the results on the optical potential parametrization and on the level density of the residual nucleus is assessed. A Hauser-Feshbach calculation is performed for the decay of the monopole giant resonance in 208 Pb using the experimental levels of 207 Pb from a recent compilation. The calculated statistical decay is in excellent agreement with recent experimental data, showing that decay of this resonance is dominantly statistical, as predicted by continuum RPA calculations. (Author) [pt

A high-order solver for aerodynamic flow simulations and comparison of different numerical schemes

Science.gov (United States)

Mikhaylov, Sergey; Morozov, Alexander; Podaruev, Vladimir; Troshin, Alexey

2017-11-01

An implementation of high order of accuracy Discontinuous Galerkin method is presented. Reconstruction is done for the conservative variables. Gradients are calculated using the BR2 method. Coordinate transformations are done by serendipity elements. In computations with schemes of order higher than 2, curvature of the mesh lines is taken into account. A comparison with finite volume methods is performed, including WENO method with linear weights and single quadrature point on a cell side. The results of the following classical tests are presented: subsonic flow around a circular cylinder in an ideal gas, convection of two-dimensional isentropic vortex, and decay of the Taylor-Green vortex.

An evaluation of nodalization/decay heat/ volatile fission product release models in ISAAC code

Energy Technology Data Exchange (ETDEWEB)

Song, Yong Mann; Park, Soo Yong; Kim, Dong Ha

2003-03-01

An ISAAC computer code, which was developed for a Level-2 PSA during 1995, has developed mainly with fundamental models for CANDU-specific severe accident progression and also the accident-analyzing experiences are limited to Level-2 PSA purposes. Hence the system nodalization model, decay model and volatile fission product release model, which are known to affect fission product behavior directly or indirectly, are evaluated to both enhance understanding for basic models and accumulate accident-analyzing experiences. As a research strategy, sensitivity studies of model parameters and sensitivity coefficients are performed. According to the results from core nodalization sensitivity study, an original 3x3 nodalization (per loop) method which groups horizontal fuel channels into 12 representative channels, is evaluated to be sufficient for an optimal scheme because detailed nodalization methods have no large effect on fuel thermal-hydraulic behavior, total accident progression and fission product behavior. As ANSI/ANS standard model for decay heat prediction after reactor trip has no needs for further model evaluation due to both wide application on accident analysis codes and good comparison results with the ORIGEN code, ISAAC calculational results of decay heat are used as they are. In addition, fission product revaporization in a containment which is caused by the embedded decay heat, is demonstrated. The results for the volatile fission product release model are analyzed. In case of early release, the IDCOR model with an in-vessel Te release option shows the most conservative results and for the late release case, NUREG-0772 model shows the most conservative results. Considering both early and late release, the IDCOR model with an in-vessel Te bound option shows mitigated conservative results.

Many-particle leptonic decays of hypernuclei

International Nuclear Information System (INIS)

Lyul'ka, V.A.

1982-01-01

Leptonic decays of light hypernuclei of the type /sup A/X/sub Λ/→/sup A/-1X+p+l - +nu-bar occurring with a fairly large energy release (compared to π - meson decays) are studied. The energy and angular distributions of the decay products are calculated taking into account the strong interaction in the final state in the p-/sup A/-1X system and also the Pauli principle. The study is carried out for different sets of the kinematic variables describing decays of this type. It is shown that the effect of the final-state interaction significantly determines the energy distributions of the interacting particles and weakly affects the analogous lepton distributions in decays of this type. It is shown that it is necessary to take this effect into account in analyzing other types of hypernuclear decays with a similar energy release, namely, mesonless decays

Neutrinoless Double Beta Decay Experiments

International Nuclear Information System (INIS)

Garfagnini, A.

2014-08-01

Neutrinoless double beta decay is the only process known so far able to test the neutrino intrinsic nature: its experimental observation would imply that the lepton number is violated by two units and prove that neutrinos have a Majorana mass components, being their own anti-particle. While several experiments searching for such a rare decay have been per- formed in the past, a new generation of experiments using different isotopes and techniques have recently released their results or are taking data and will provide new limits, should no signal be observed, in the next few years to come. The present contribution reviews the latest public results on double beta decay searches and gives an overview on the expected sensitivities of the experiments in construction which will be able to set stronger limits in the near future. EXO and KamLAND-Zen experiments are based on the decay of Xe 136 , GERDA and MAJORANA experiments are based on the decay of Ge 76 , and the CUORE experiment is based on the decay of Te 130

JEF-2.2 radioactive decay data

International Nuclear Information System (INIS)

1994-08-01

This work deals with the JEF-2.2 radioactive decay data and is divided into four tables. The first table presents the origin of the JEF-2.2 radioactive decay data and subsequent modifications. The second one is a summary of the JEF-2.2 radioactive decay data file. The third one describes the JEF-2.2 fission products and the main decay and fission yield data. The last one consists of the main decay parameters from the JEF-2.2, ENDF/B-VI and JNDC-2.0 libraries. (O.L.). 100 figs., 4 tabs

Decay spectroscopy of neutron-rich nuclei with the CAITEN detector

Energy Technology Data Exchange (ETDEWEB)

Steiger, Konrad [Physik-Department E12, Technische Universitaet Muenchen (Germany); Collaboration: CAITEN-Collaboration

2012-07-01

An experiment in fall 2010 at the RIBF (Radioactive Ion Beam Factory at RIKEN, Japan) investigated the neutron-rich nuclei in the neighborhood of {sup 30}Ne and {sup 36}Mg. These nuclei were produced by relativistic projectile fragmentation of a 345 AMeV {sup 48}Ca primary beam which was delivered from the superconducting ring cyclotron SRC with an average intensity of 70 pnA. The secondary cocktail beam was separated and identified with the BigRIPS fragment separator and the ZeroDegree spectrometer. The unambiguous particle identification was achieved by measuring the energy loss, time of flight and magnetic rigidity event-by-event. The identified fragments were implanted in the CAITEN detector (Cylindrical Active Implantation Target for Efficient Nuclear-decay study). The main part of this detector is a 4 x 10{sup 4}-fold segmented plastic scintillator with the shape of a hollow cylinder. To reduce background events the scintillator was moved continuously in axial and vertical direction (similar to a tape-transporting system). Implantations and decays were correlated in time and space. {gamma}-rays were detected with three germanium clover detectors. For the first time {beta}-delayed gammas were measured in the neutron-rich isotopes {sup 36-38}Si. The status of the analysis and preliminary results including new half-life values and tentative level schemes for these very exotic nuclei are presented.

Dental Caries (Tooth Decay)

Science.gov (United States)

... Materials Contact Us Home Research Data & Statistics Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Dental Caries (Tooth Decay)

Science.gov (United States)

... Contact Us Home Research Data & Statistics Share Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Decay data evaluation project: Evaluation of 52Mn and 52mMn nuclear decay data

Science.gov (United States)

Luca, Aurelian

2017-09-01

All nuclear decay data within the 52Fe-52m,52Mn-52Cr decay chain have been evaluated at IFIN-HH, Romania, as part of an IAEA coordinated research project (F41029) and incorporated into the Decay Data Evaluation Project (DDEP). Both 52Fe and daughter 52Mn are two potentially promising radionuclides to be incorporated into suitable radiopharmaceuticals for PET and SPECT imaging. The decay data evaluation of 52Fe has previously been published and reported to the IAEA Nuclear Data Section. Equivalent DDEP evaluations for 52Mn and 52mMn have also been completed recently, and are presented in summary form below. These improved decay data sets have also been reported to the IAEA in detail, and are highly suitable in dose rate calculations for their application in nuclear medicine.

Weak radiative hyperon decays

International Nuclear Information System (INIS)

Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

1990-01-01

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 + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

Rare decays of B-mesons

International Nuclear Information System (INIS)

Ali, A.

1991-07-01

This paper is organized as follows. First, we discuss the decay rates for b → (s,d) + γ in the lowest order (1 loop) and including the QCD corrections in the effective Hamiltonian method. The photon energy spectrum in the inclusive decays B → X s + γ is evaluated in this approach and the dominant background from the CC decays B → X c + γ is presented. Next, we discuss the calculations for the inclusive decays b → s + anti l (l = e,μ,ν), including the QCD corrections. Finally, we summarize rate estimates for the exclusive rare decays of the B-meson, B → K*γ, and B → (K,K*) anti l (l = e,μ,ν), as well as B o s,d → γγ and B o s,d → l + l - with (l = e,μ,r). (orig./HSI)

The β-decay Paul trap: A radiofrequency-quadrupole ion trap for precision β-decay studies

International Nuclear Information System (INIS)

Scielzo, N.D.; Li, G.; Sternberg, M.G.; Savard, G.; Bertone, P.F.; Buchinger, F.; Caldwell, S.; Clark, J.A.; Crawford, J.; Deibel, C.M.; Fallis, J.; Greene, J.P.

2012-01-01

The β-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision β-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following β decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of β-decay angular correlations in the decay of 8 Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup α particles. Many other β-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.

The {beta}-decay Paul trap: A radiofrequency-quadrupole ion trap for precision {beta}-decay studies

Energy Technology Data Exchange (ETDEWEB)

Scielzo, N.D., E-mail: scielzo1@llnl.gov [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Li, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Sternberg, M.G.; Savard, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Bertone, P.F. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Buchinger, F. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Caldwell, S. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Clark, J.A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Crawford, J. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Deibel, C.M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824 (United States); Fallis, J. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); Greene, J.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); and others

2012-07-21

The {beta}-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision {beta}-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following {beta} decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of {beta}-decay angular correlations in the decay of {sup 8}Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup {alpha} particles. Many other {beta}-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.

Total β-decay energies and atomic masses in regions far from β-stability

International Nuclear Information System (INIS)

Aleklett, K.

1977-01-01

This thesis is a summary of experimental investigations on total β-decay energies and deduced atomic masses of nuclei far from the region of β-stability. The Qsub(β) values are given for isotopes of Zn, Ga, Ge, As, Br, Rb, In, Sn, Sb, Te, Cs, Fr, Ra and Ac, with β-unstable nuclei. These unstable nuclei have very short half-lives, often below 10s, and the experimental techniques for the production, separation and collection of these short-lived nuclei are described. Neutron deficient nuclides were produced by spallation, in the ISOLDE facility, and neutron deficient nuclides were produced by thermal neutron induced fission of 235 U in the OSIRIS facility. β-spectra were recorded using an Si(Li)-detector and a coincidence system. Qsub(β) values obtained from mass formulae have been compared with experimental values obtained in different mass regions and a comparison made between results obtained from different droplet mass formulae. (B.D.)

Study of the decay 184Hg→184Au (Tsub(1/2)=30s)

International Nuclear Information System (INIS)

Nettles, W.G.; Beraud, R.; Cole, J.D.; Hamilton, J.H.; Ramayya, A.V.; Kawakami, H.; Spejewski, E.H.

1978-01-01

The radioactive decay of 184 Hg to 184 Au was studied on line with the UNISOR isotope separator. The 184 mass chain was entered at 184 Tl and 184 Hg by bombarding an isotopically-enriched target of 180 W with 14 N ions of 177 MeV. Multiscale singles and γ-γ-time coincidence studies were carried out. No previous levels have been assigned to 184 Au. From the coincidence data eight levels at 156.2, 159.1, 247.7, 282.8, 295.1, 392.4, 418.0 and 412.4 keV are assigned and two tentative levels at 534.0 and 551.6 keV are proposed. By using the delayed coincidence technique, a half-life of 36+-6 nanoseconds was measured for the 156.2 keV first-excited level and upper limits of 2 nanoseconds were determined for the half-lives of levels at 159.1, 247.7, 295.1 and 392.4 keV [fr

Excited state transitions in 2νββ decays of {sup 76}Ge from phase I of the GERDA experiment

Energy Technology Data Exchange (ETDEWEB)

Wester, Thomas [IKTP, TU Dresden (Germany); Collaboration: GERDA-Collaboration

2015-07-01

The Germanium Detector Array GERDA is an experiment searching for the neutrinoless double beta decay in {sup 76}Ge. The observation of such a decay would prove the Majorana character of the neutrino and could provide a hint about the neutrino mass and possibly identify the mass hierarchy scheme. The half life of the neutrino accompanied double beta decay (2νββ) of {sup 76}Ge has been measured by GERDA Phase I with unprecedented precision. The observed spectrum comes mostly from the transition from the 0{sup +} ground state of {sup 76}Ge to the 0{sup +} ground state of {sup 76}Se. However, phase space suppressed 2νββ transitions to excited states of {sup 76}Se exist as well. At current state, the predicted half lives for such decays vary by several orders of magnitude, due to the large uncertainties in the nuclear matrix elements and the available nuclear models. An observation would therefore help to constrain model parameters and decrease those uncertainties. This study investigates the 2νββ decay of {sup 76}Ge into various excited states of {sup 76}Se using the data from GERDA Phase I. An event counting method is performed based on coincident events between two germanium detectors. Several analysis parameters are optimized with the help of Monte Carlo simulations to maximize the sensitivity. The presentation discusses the procedure and results of this analysis.

Induced nuclear beta decay

International Nuclear Information System (INIS)

Reiss, H.R.

1986-01-01

Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

Reduction of environmental impact by FR cycle deployment

International Nuclear Information System (INIS)

Katoh, Atsushi; Nakai, Ryodai

2005-03-01

In this report radioactive waste generations in terms of disposal volume or disposal field equivalent, and the radioactive toxicity of HLW are evaluated to clarify the promising nuclear scenario for the sake of realization of sustainable society in 21st century. This analysis was conducted based on the outcomes of the mass flow evaluation tool 'FAMILY-21' which calculates a material balance for TRU in the following scenarios. 1) LWR once-through scenario, 2) Pu partly recycling in LWR scenario, 3) Pu full recycling in LWR scenario, 4) FBR deployment scenario, 5) Interim storage scenario. The result shows that the cumulative area of low level radioactive waste (LLW) disposal field at 2150 in the FR cycle deployment scenario is 1.8 times larger than that in the LWR once-through scenario. The area of LLW disposal field at 2150 is a few km 2 in all the scenarios. In contrast, the cumulative area of high level radioactive waste (HLW) disposal field at 2150 in the FR cycle deployment scenario is less than half of that in the LWR once-through scenario. The area of HLW disposal field at 2150 is about 10 times of the area of LLW disposal field. Moreover, the FR deployment reduces the radioactive toxicity of HLW by U/TRU recycling, and shortens the period to decay under the natural Uranium toxicity level. Considering the area of radioactive waste disposal field and the radioactive toxicity of HLW, the advantage of the FR cycle deployment is indicated quantitatively from the viewpoint of the environmental burden reduction. (author)

Three-body charmless B decays workshop

Energy Technology Data Exchange (ETDEWEB)

Ben-Haim, E.; Chauveau, J.; Hartfiel, B.; Ocariz, J. [Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE), 75 - Paris (France); Charles, J. [LPT, 13 - Marseille (France)

2006-07-01

The purpose of this workshop was multifarious: -) to present and discuss the current experimental perspectives based on the full expected statistics from B-factories by 2008, -) to share and further develop analysis methods, -) to present and discuss the theoretical work on the subject, -) to discuss the future of B-factories, and -) to establish a work plan until 2009. The contributions have focused on 3 body charmless B decays and mostly 3 body hadronic charmless B decays, they have also dealt with semileptonic decays, radiative decays, charm and charmonium decays, and scattering processes. This document gathers the slides of the presentations.

Constraints on hadronically decaying dark matter

Energy Technology Data Exchange (ETDEWEB)

Garny, Mathias [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Tran, David [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy

2012-05-15

We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

Three-body charmless B decays workshop

International Nuclear Information System (INIS)

Ben-Haim, E.; Chauveau, J.; Hartfiel, B.; Ocariz, J.; Charles, J.

2006-01-01

The purpose of this workshop was multifarious: -) to present and discuss the current experimental perspectives based on the full expected statistics from B-factories by 2008, -) to share and further develop analysis methods, -) to present and discuss the theoretical work on the subject, -) to discuss the future of B-factories, and -) to establish a work plan until 2009. The contributions have focused on 3 body charmless B decays and mostly 3 body hadronic charmless B decays, they have also dealt with semileptonic decays, radiative decays, charm and charmonium decays, and scattering processes. This document gathers the slides of the presentations

Constraints on hadronically decaying dark matter

International Nuclear Information System (INIS)

Garny, Mathias; Ibarra, Alejandro; Tran, David; Minnesota Univ., Minneapolis, MN

2012-05-01

We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons.We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

Search for new mechanism of CP violation through decay of leptons and semileptonic decay of hadrons

International Nuclear Information System (INIS)

Tsai, Y.S.

1996-11-01

If CP is violated in any decay process involving leptons it will signify the existence of a new scalar boson (called the X boson) responsible for CP violation that may be the key to understanding matter-antimatter asymmetry in the universe. The authors discuss the signatures of CP violation in (1) the decay of tau and mu leptons, and (2) the semileptonic decay of π, K, D, B and t particles by measuring the polarization of the charged lepton in the decay. The authors discuss how the coupling constants and their phases of the coupling of the X boson to 9 quark vertices and 3 lepton vertices can be obtained through 12 decay processes

The Higgs boson inclusive decay channels $H \\to b\\bar{b}$ and $H \\to gg$ up to four-loop level

OpenAIRE

Wang, Sheng-Quan; Wu, Xing-Gang; Zheng, Xu-Chang; Shen, Jian-Ming; Zhang, Qiong-Lian

2013-01-01

The principle of maximum conformality (PMC) has been suggested to eliminate the renormalization scheme and renormalization scale uncertainties, which are unavoidable for the conventional scale setting and are usually important errors for theoretical estimations. In this paper, by applying PMC scale setting, we analyze two important inclusive Standard Model Higgs decay channels, H→bb¯ and H→gg , up to four-loop and three-loop levels, respectively. After PMC scale setting, it is found that the ...

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

Isospin Mixing in Nuclei Around N ∼ Z and the Superallowed β-Decay

International Nuclear Information System (INIS)

Satula, W.; Dobaczewski, J.; Nazarewicz, W.; Rafalski, M.

2011-01-01

Theoretical approaches that use one-body densities as dynamical variables, such as Hartree-Fock or the density functional theory (DFT), break isospin symmetry both explicitly, by virtue of charge-dependent interactions, and spontaneously. To restore the spontaneously broken isospin symmetry, we implemented the isospin-projection scheme on top of the Skyrme-DFT approach. This development allows for consistent treatment of isospin mixing in both ground and exited nuclear states. In this study, we apply this method to evaluate the isospin impurities in ground states of even-even and odd-odd N ∼ Z nuclei. By including simultaneous isospin and angular-momentum projection, we compute the isospin-breaking corrections to the 0 + → 0 + superallowed β-decay. (authors)

Decay of 132Cs and nuclear structure of 132Xe

International Nuclear Information System (INIS)

Cruz, M.T.F. da; Goldman, I.D.

1989-02-01

Gamma spectroscopy, coincidence and angular correlation experiments were performed, in an extensive study of 132 Cs decay. The population intensities of states in 132 Ba were measured, some upper limits were determined and the value of the transition to the 4 1 + state of 132 Ba has drastically changed. A new gamma transition of 688 KeV was detected and located in the level scheme of 132 Xe. The angular correlation measurements were performed with a Ge(Li)-NaI(Tl) spectrometer and helped in choosing the spin value for the 1804 KeV state of 132 Xe. Kumar-Baranger-type calculations were performed for the 132 Xe fairly good results. The resulting potential energy surface for 132 Xe is very different from that of Gneuss and Greiner model, suggesting the need for any quadrupole moment measurement for this nucleus. (author) [pt

Level structure of 149Nd. The decay of 149Pr

International Nuclear Information System (INIS)

Pinston, J.A.; Roussille, R.; Sadler, G.; Tenten, W.; Bocquet, J.P.; Pfeiffer, B.; Warner, D.D.

1977-01-01

The decay of 149 Pr (Tsub(1/2) = 2.2 min) has been studied using the two fission product separators JOSEF and LOHENGRIN to produce the 149 Pr nucleus. A level scheme for 149 Nd has been established. The β-branching of log ft values for the excited levels were deduced from the analysis of γ-intensity balances. Furthermore, the spins and parities for most of the excited states observed were obtained from the comparison between the present work, the neutron capture results and the pick-up reactions. The positive parity levels have been described with the Nilsson model with Coriolis and ΔN = 2 interactions included. The properties of the negative parity states cannot be explained as easily; however, it has been attempted to extract the structure of the ground state and the first excited states. (orig.) [de

Weak decays of heavy quarks

International Nuclear Information System (INIS)

Gaillard, M.K.

1978-08-01

The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references

Evidence of interatomic Coulombic decay in ArKr after Ar 2p Auger decay

International Nuclear Information System (INIS)

Morishita, Y; Saito, N; Suzuki, I H; Fukuzawa, H; Liu, X-J; Sakai, K; Pruemper, G; Ueda, K; Iwayama, H; Nagaya, K; Yao, M; Kreidi, K; Schoeffler, M; Jahnke, T; Schoessler, S; Doerner, R; Weber, T; Harries, J; Tamenori, Y

2008-01-01

We have identified interatomic Coulombic decay (ICD) processes in the ArKr dimer following Ar 2p Auger decay, using momentum-resolved electron-ion-ion coincidence spectroscopy and simultaneously determining the kinetic energy of the ICD electron and the KER between Ar 2+ and Kr + . We find that the spin-conserved ICD processes in which Ar 2+ (3p -3 3d) 1 P and 3 P decay to Ar 2+ (3p -2 ) 1 D and 3 P, respectively, ionizing the Kr atom, are significantly stronger than the spin-flip ICD processes in which Ar 2+ (3p -3 3d) 1 P and 3 P decay to Ar 2+ (3p -2 ) 3 P and 1 D, respectively

The Decay Data Evaluation Project (DDEP) and the JEFF-3.3 radioactive decay data library: Combining international collaborative efforts on evaluated decay data

Science.gov (United States)

Kellett, Mark A.; Bersillon, Olivier

2017-09-01

The Decay Data Evaluation Project (DDEP), is an international collaboration of decay data evaluators formed with groups from France, Germany, USA, China, Romania, Russia, Spain and the UK, mainly from the metrology community. DDEP members have evaluated over 220 radionuclides, following an agreed upon methodology, including a peer review. Evaluations include all relevant parameters relating to the nuclear decay and the associated atomic processes. An important output of these evaluations are recommendations for new measurements, which can serve as a basis for future measurement programmes. Recently evaluated radionuclides include: 18F, 59Fe, 82Rb, 82Sr, 88Y, 90Y, 89Zr, 94mTc, 109Cd, 133Ba, 140Ba, 140La, 151Sm and 169Er. The DDEP recommended data have recently been incorporated into the JEFF-3.3 Radioactive Decay Data Library. Other sources of nuclear data include 900 or so radionuclides converted from the Evaluated Nuclear Structure Data File (ENSDF), 500 from two UK libraries (UKPADD6.12 and UKHEDD2.6), the IAEA Actinide Decay Data Library, with the remainder converted from the NUBASE evaluation of nuclear properties. Mean decay energies for a number of radionuclides determined from total absorption gamma-ray spectroscopy (TAGS) have also been included, as well as more recent European results from TAGS measurements performed at the University of Jyväskylä by groups from the University of Valencia, Spain and SUBATECH, the University of Nantes, France. The current status of the DDEP collaboration and the JEFF Radioactive Decay Data Library will be presented. Note to the reader: the pdf file has been changed on September 22, 2017.

CP violation in rare K decays

International Nuclear Information System (INIS)

Ecker, G.

1990-01-01

The investigation of rare K decays calls for a unified treatment of short- and long-distance aspects as provided by chiral perturbation theory. For the standard model with three generations, the theoretical predictions for signals of CP violation in those decays are reviewed. With direct CP violation as the main target, special emphasis is given to the charge asymmetries in charged K decays and to the especially rare decays K L → π 0 ll-bar. Time dependent rate asymmetries in K 0 decays and the longitudinal muon polarization in K L → μ + μ - are also discussed. 50 refs., 3 figs., 1 tab. (Author)

Colour schemes

DEFF Research Database (Denmark)

van Leeuwen, Theo

2013-01-01

This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

B decays to baryons

Indian Academy of Sciences (India)

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.

Fine structure of cluster decays

International Nuclear Information System (INIS)

Dumitrescu, O.

1993-07-01

Within the one level R-matrix approach the hindrance factors of the radioactive decays in which are emitted α and 14 C - nuclei are calculated. The generalization to radioactive decays in which are emitted heavier clusters such as e.g. 20 O, 24 Ne, 25 Ne, 28 Mg. 30 Mg, 32 Si and 34 Si is straightforward. The interior wave functions are supposed to be given by the shell model with effective residual interactions (e.g. the large scale shell model code-OXBASH - in the Michigan State University version for nearly spherical nuclei or by the enlarged superfluid model - ESM - recently proposed for deformed nuclei). The exterior wave functions are calculated from a cluster - nucleus double - folding model potential obtained with the M3Y interaction. As examples of the cluster decay fine structure we analyzed the particular cases of α - decay of 241 Am and 14 C -decay of 233 Ra. Good agreement with the experimental data is obtained. (author). 78 refs, 2 figs, 6 tabs

The generation of the Greenberger-Horne-Zeilinger state of four distant atoms conditioned on cavity decay

International Nuclear Information System (INIS)

Pahlke, Kai; Zou Xubo; Mathis, Wolfgang

2004-01-01

We show a way to use an optical device set-up to generate the four-particle Greenberger-Horne-Zeilinger (GHZ) state of atoms, which are trapped separately in leaky cavities. Based on cavity decay, photons are transferred from the atom-cavity systems to a symmetric series of beam splitters and photon detectors. The events of photon detection on the output modes of the beam splitters project the state of the atom-cavity systems onto the GHZ state. It is briefly pointed out how this scheme can be extended to generate GHZ states of 4m atoms

Rare beauty and charm decays

International Nuclear Information System (INIS)

Blake, T.

2016-01-01

Rare beauty and charm decays can provide powerful probes of physics beyond the Standard Model. These proceedings summarise the latest measurements of rare beauty and charm decays from the LHCb experiment at the end of Run 1 of the LHC. Whilst the majority of the measurements are consistent with SM predictions, small differences are seen in the rate and angular distribution of b → sℓ"+ℓ"− decay processes.

Beta decay and rhenium cosmochronology

International Nuclear Information System (INIS)

Ashktorab, K.

1992-01-01

Among the problems which limit the use of the 187 Re/ 187 Os isobaric pair as a cosmochronometer for the age of the galaxy and the universe are the uncertainties in the partial half-lives of the continuum and bound state decays of 187 Re. While the total half-life of the decay is well established, the partial half-life for the continuum decay is uncertain, and several measurements are not compatible. A high temperature quartz proportional counter was used in this work to remeasure the continuum β - decay of 187 Re. The β endpoint energy for the decay of neutral 187 Re to singly ionized 187 Os of 2.75 ± 0.06 keV agrees with the earlier results. The corresponding half-life of (45 ± 3) x 10 9 years improves and agrees with the earlier measurement of Payne and Drever and refutes other measurements. Based on the new half-life for the continuum decay and a total half-life of (43.5 ± 1.3) x 10 9 years reported by Linder et al., the branching ratio for the bound state decay into discrete atomic states is estimated to be (3 ± 6)% in agreement with the most recent calculated theoretical branching ratio of approximately 1%. Anomalies in beta spectra reported by J.J. Simpson and others have been attributed to a 17 keV heavy-neutrino admixture. If confirmed, the implications from the existence of such a neutrino for particle and astrophysics would be significant. A multiwire open-quotes wall-lessclose quotes stainless steel proportional counter has been used in the present work to investigate the spectral shape of the β decay of 63 Ni. No anomalies in the spectral shape were observed which could be attributed to the presence of 17 keV heavy neutrino

On t-quark decay

International Nuclear Information System (INIS)

Chizhov, M.V.

1995-07-01

An extended electroweak model with second rank antisymmetric tensor field is proposed. The effective interactions resulting from the exchange of these fields have specific dependence on the transfer momentum. This leads to the introduction of new model-independent muon decay parameters (Mod. Phys. Lett. A9 (1994) 2979), which can be measured experimentally in SLAC and TRIUMF. The new tensor interactions can effect the three-particles semileptonic meson decays (Mod. Phys. Lett. A8 (1993) 2753). In this connection it will be interesting to propose new experiments on K + → l + νγ, K + → π 0 l + ν decays in DAΦNE. The K L -K s mass difference sets constraints on the tensor particles masses. The mass of the lightest tensor particle could be less than the t-quark mass. Therefore the lightest tensor particle may give an additional to the W-boson contribution into the t- quark decay with the same signature. (author). 10 refs, 2 figs

Black hole decay as geodesic motion

International Nuclear Information System (INIS)

Gupta, Kumar S.; Sen, Siddhartha

2003-01-01

We show that a formalism for analyzing the near-horizon conformal symmetry of Schwarzschild black holes using a scalar field probe is capable of describing black hole decay. The equation governing black hole decay can be identified as the geodesic equation in the space of black hole masses. This provides a novel geometric interpretation for the decay of black holes. Moreover, this approach predicts a precise correction term to the usual expression for the decay rate of black holes

Testing the standard model with precision calculations of semileptonic B-decays

Energy Technology Data Exchange (ETDEWEB)

Turczyk, Sascha S.

2011-01-14

Measurements in the flavour sector are very important to test the Standard Model, since most of the free parameters are related to flavour physics. We are discussing semileptonic B-meson decays, from which an important parameter, vertical stroke V{sub cb} vertical stroke, is extracted. First we discuss higher-order non-perturbative corrections in inclusive semileptonic decays of B mesons. We identify the relevant hadronic matrix elements up to 1/m{sup 5}{sub b} and estimate them using an approximation scheme. Within this approach the e ects on the integrated rate and on kinematic moments are estimated. Similar estimates are presented for B {yields} X{sub s} + {gamma} decays. Furthermore we investigate the role of so-called ''intrinsic-charm'' operators in this decay, which appear first at order 1/m{sup 3}{sub b} in the heavy-quark expansion. We show by explicit calculation that - at scales {mu} {<=} m{sub c} - the contributions from ''intrinsic-charm'' effects can be absorbed into short-distance coefficient functions multiplying, for instance, the Darwin term. Then, the only remnant of ''intrinsic charm'' are logarithms of the form ln(m{sup 2}{sub c}/m{sup 2}{sub b}), which can be resummed by using renormalization-group techniques. As long as the dynamics at the charm quark scale is perturbative, {alpha}{sub s}(m{sub c}) << 1, this implies that no additional non-perturbative matrix elements aside from the Darwin and the spin-orbit term have to be introduced at order 1/m{sup 3}{sub b}. However, ''intrinsic charm'' leads at the next order to terms with inverse powers of the charm mass: 1/m{sup 3}{sub b} x 1/m{sup 2}{sub c}. Parametrically they complement the estimate of the potential impact of 1/m{sup 4}{sub b} contributions, which we will explore. In this context, we draw semiquantitative conclusions for the expected scale of weak annihilation in semileptonic B decays, both for its

Generic Schemes for Single-Molecule Kinetics. 3: Self-Consistent Pathway Solutions for Nonrenewal Processes.

Science.gov (United States)

Piephoff, D Evan; Cao, Jianshu

2018-04-23

We recently developed a pathway analysis framework (paper 1) for describing single-molecule kinetics for renewal (i.e., memoryless) processes based on the decomposition of a kinetic scheme into generic structures. In our approach, waiting time distribution functions corresponding to such structures are expressed in terms of self-consistent pathway solutions and concatenated to form measurable probability distribution functions (PDFs), affording a simple way to decompose and recombine a network. Here, we extend this framework to nonrenewal processes, which involve correlations between events, and employ it to formulate waiting time PDFs, including the first-passage time PDF, for a general kinetic network model. Our technique does not require the assumption of Poissonian kinetics, permitting a more general kinetic description than the usual rate approach, with minimal topological restrictiveness. To demonstrate the usefulness of this technique, we provide explicit calculations for our general model, which we adapt to two generic schemes for single-enzyme turnover with conformational interconversion. For each generic scheme, wherein the intermediate state(s) need not undergo Poissonian decay, the functional dependence of the mean first-passage time on the concentration of an external substrate is analyzed. When conformational detailed balance is satisfied, the enzyme turnover rate (related to the mean first-passage time) reduces to the celebrated Michaelis-Menten functional form, consistent with our previous work involving a similar scheme with all rate processes, thereby establishing further generality to this intriguing result. Our framework affords a general and intuitive approach for evaluating measurable waiting time PDFs and their moments, making it a potentially useful kinetic tool for a wide variety of single-molecule processes.

Determination of the radiative decay width of the positive K*+(890) meson

International Nuclear Information System (INIS)

Chandlee, C.D.

1983-01-01

A systematic study of the coherent excitation of high energy pions and kaons by nuclear targets has been completed at Fermilab (Experiment 272) with the intent of extracting the radiative decay widths of the various vector and tensor mesons. This work was initiated to furnish experimental results for comparison with theoretical predictions based on unitary symmetry schemes, quark models, and vector dominance models with the hope of shedding light on the structure of the quark-antiquark system. The work presented here deals with data collected during the second running period of E272 on the excitation of incident 200 GeV/c K + by copper and lead targets for the purpose of precisely determining the radiative width from the transition K* + (890) → K + γ. The experiment was performed in the MIE secondary beam line of the Meson Lab utilizing an enhanced, Cherenkov tagged, positive kaon beam, a forward charged particle spectrometer consisting of drift and proportional wire chambers, and a liquid argon colorimeter for photon detection. A Primakoff type analysis of excitation in the nuclear Coulomb field including a strong contribution to the coherent production process from isoscalar exchange was applied to data for both the K + π 0 and K/sub S/ 0 π + decay modes of the K* +

Three-Phased Wake Vortex Decay

Science.gov (United States)

Proctor, Fred H.; Ahmad, Nashat N.; Switzer, George S.; LimonDuparcmeur, Fanny M.

2010-01-01

A detailed parametric study is conducted that examines vortex decay within turbulent and stratified atmospheres. The study uses a large eddy simulation model to simulate the out-of-ground effect behavior of wake vortices due to their interaction with atmospheric turbulence and thermal stratification. This paper presents results from a parametric investigation and suggests improvements for existing fast-time wake prediction models. This paper also describes a three-phased decay for wake vortices. The third phase is characterized by a relatively slow rate of circulation decay, and is associated with the ringvortex stage that occurs following vortex linking. The three-phased decay is most prevalent for wakes imbedded within environments having low-turbulence and near-neutral stratification.

Rare KL decays at Fermilab

International Nuclear Information System (INIS)

Schnetzer, St.

1997-01-01

Recent results and the future prospects for rare K L decay at Fermilab are described. A summary of all rare decay results from E799 Phase I (the 1991 run) are presented. Three new results: K L → e + e - μ + μ - , K L → π 0 μe, and π 0 → e + e - e + e - are discussed in detail. Improvements for KTeV (the 1996-1997 run) are discussed and the expected sensitivities listed. Finally, the KAMI program for rare decays with the Main Injector (2000 and beyond) is presented with emphasis on a search for the decay K L → π 0 νν-bar at O(10 -12 ) single-event-sensitivity. (author)

Is neutrinoless double beta decay suppressed

International Nuclear Information System (INIS)

Tomoda, T.

1989-01-01

Much effort has been devoted to the study of nuclear double beta decay, since the observation of a neutrinoless double beta (OνΒΒ) decay would be clear evidence that the electron neutrino is a Majorana particle. The OνΒΒ decay is caused by a finite Majorana neutrino mass and/or an admixture of right-handed leptonic currents. In order to relate these quantities to OνΒΒ decay rates, we need nuclear matrix elements, which are model dependent. One of the possibilities of testing nuclear models employed in such analysis is to calculate the experimentally known rates of ΒΒ decay with emission of two neutrinos (2νΒΒ decay) which occurs independently of the nature of the neutrino. There was a long-standing difficulty in such attempts that the calculated 2νΒΒ decay rates turned out to be always too large by one to two orders of magnitude. Trying to overcome such difficulty, Klapdor and Grotz as well as Vogel and Zirnbauer showed in their calculation using schematic effective interactions such that 2νΒΒ decay rates can get reduced considerably due to the nuclear ground state correlations. This paper reports that the suppression is ascribed to that of the virtual Gamow-Teller transitions from the excited 1 + states of the intermediate odd-odd -even nucleus

The weak decay of helium hypernuclei

International Nuclear Information System (INIS)

Athanas, M.J.

1992-08-01

A Λ hyperon replaces a neutron in a nucleus to form a hypernucleus via the A X(K - , π - ) Λ A X reaction at 750 MeV/c (Brookhaven Experiment 788). The free Λ decay rates Γ(Λ → pπ - ) and Γ(Λ → nπ 0 ) are diminished due to Pauli blocking; but a non-mesonic decay mode, nucleon stimulated decay NΛ → Nn, is present and is detected via the energetic decay nucleon(s) (∼ 400MeV/c). Measurements of the various hypernuclear decay rates Γ(Λ → pπ - ), Γ(Λ → nπ 0 ) and Γ(Λn → nn) provides insight into the strong modification of the weak interaction such as the baryon-baryon ΔI =1/2 rule. The hypernuclear state is isolated by momentum analysis of (K - , π - ) target reaction. Out-of-beam large volume scintillation detectors and tracking chambers axe used to make particle identification of the hypernuclear decay products by time-of-flight, dE/dx, and range. The kinetic energy of the decay neutrons are measured by time of flight using the large volume 100 element neutron detector system. The hypernuclear lifetime is directly measured using precision scintillator counters and tracking chambers. Measurements of the various decay rates as well as the total lifetime are discussed for Λ 4 He

Development of limiting decay heat values

International Nuclear Information System (INIS)

Khotylev, V.A.; Thompson, J.W.; Gibb, R.A.

1999-01-01

A number of tools are used in the assessment of decay heat during an outage of the CANDU-6. Currently, the technical basis for all of these tools is 'CANDU Channel Decay Power', Reference 1. The methods used in that document were limited to channel decay powers. However, for most outage support analysis, decay heat limits are based on bundle heats. Since the production of that document in 1977, new versions of codes, and updates of general-purpose and CANDU-specific libraries have become available. These tools and libraries have both a more formal technical basis than Reference 1, and also a more formal validation base. Using these tools it is now possible to derive decay heat with more specific input parameters, such as fuel composition, heat per unit of fuel, and irradiation history, and to assign systematically derived uncertainty allowances to such decay heat values. In particular, we sought to examine a broad range of likely bundle histories, and thus establish a set of limiting bundle decay beat values, that could serve as a bounding envelope for use in Nuclear Safety Analysis. (author)

Multiple photon emission in heavy particle decays

International Nuclear Information System (INIS)

Asakimori, K.; Burnett, T.H.; Cherry, M.L.

1994-03-01

Cosmic ray interactions, at energies above 1 TeV/nucleon, in emulsion chambers flown on high altitude balloons have yielded two events showing apparent decays of a heavy particle into one charged particle and four photons. The photons converted into electron pairs very close to the decay vertex. Attempts to explain this decay topology with known particle decays are presented. Unless both events represent a b → u transition, which is statistically unlikely, then other known decay modes for charmed or bottom particles do not account satisfactorily for these observations. This could indicate, possibly, a new decay channel. (author). 7 refs, 6 figs, 2 tabs

Inclusive J/{psi} and {psi}(2S) production from b-hadron decay in p anti p and pp collisions

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, Paolo; Kniehl, Bernd A.; Kramer, Gustav [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2013-09-15

We study the inclusive production of J/{psi} and (2S) mesons originating from the decays of bottom-flavored hadrons produced in p anti p collisions at the Fermilab Tevatron and in pp collisions at the CERN LHC. We work at next-to-leading order in the general-mass variable-flavor-number scheme (GM-VFNS) implemented with nonperturbative fragmentation functions fitted to e{sup +}e{sup -} data of inclusive b-hadron production exploiting their universality. The three-momentum distributions of the charmonia are extracted from B-decay data in the framework of nonrelativistic-QCD factorization. Comparing the theoretical predictions thus obtained with transverse-momentum distributions measured by the CDF II, ALICE, ATLAS, CMS, and LHCb Collaborations, we find excellent overall agreement as for both absolute normalization and lineshape, which provides a nontrivial test of the GM-VFNS over wide ranges of center-of-mass energy, transverse momentum, and rapidity.

The decay width of stringy hadrons

Directory of Open Access Journals (Sweden)

Jacob Sonnenschein

2018-02-01

We fit the theoretical decay width to experimental data for mesons on the trajectories of ρ, ω, π, η, K⁎, ϕ, D, and Ds⁎, and of the baryons N, Δ, Λ, and Σ. We examine both the linearity in L and the exponential suppression factor. The linearity was found to agree with the data well for mesons but less for baryons. The extracted coefficient for mesons A=0.095±0.015 is indeed quite universal. The exponential suppression was applied to both strong and radiative decays. We discuss the relation with string fragmentation and jet formation. We extract the quark–diquark structure of baryons from their decays. A stringy mechanism for Zweig suppressed decays of quarkonia is proposed and is shown to reproduce the decay width of ϒ states. The dependence of the width on spin and flavor symmetry is discussed. We further apply this model to the decays of glueballs and exotic hadrons.

Complex degradation processes lead to non-exponential decay patterns and age-dependent decay rates of messenger RNA.

Directory of Open Access Journals (Sweden)

Carlus Deneke

Full Text Available Experimental studies on mRNA stability have established several, qualitatively distinct decay patterns for the amount of mRNA within the living cell. Furthermore, a variety of different and complex biochemical pathways for mRNA degradation have been identified. The central aim of this paper is to bring together both the experimental evidence about the decay patterns and the biochemical knowledge about the multi-step nature of mRNA degradation in a coherent mathematical theory. We first introduce a mathematical relationship between the mRNA decay pattern and the lifetime distribution of individual mRNA molecules. This relationship reveals that the mRNA decay patterns at steady state expression level must obey a general convexity condition, which applies to any degradation mechanism. Next, we develop a theory, formulated as a Markov chain model, that recapitulates some aspects of the multi-step nature of mRNA degradation. We apply our theory to experimental data for yeast and explicitly derive the lifetime distribution of the corresponding mRNAs. Thereby, we show how to extract single-molecule properties of an mRNA, such as the age-dependent decay rate and the residual lifetime. Finally, we analyze the decay patterns of the whole translatome of yeast cells and show that yeast mRNAs can be grouped into three broad classes that exhibit three distinct decay patterns. This paper provides both a method to accurately analyze non-exponential mRNA decay patterns and a tool to validate different models of degradation using decay data.

On the decay of homogeneous isotropic turbulence

Science.gov (United States)

Skrbek, L.; Stalp, Steven R.

2000-08-01

Decaying homogeneous, isotropic turbulence is investigated using a phenomenological model based on the three-dimensional turbulent energy spectra. We generalize the approach first used by Comte-Bellot and Corrsin [J. Fluid Mech. 25, 657 (1966)] and revised by Saffman [J. Fluid Mech. 27, 581 (1967); Phys. Fluids 10, 1349 (1967)]. At small wave numbers we assume the spectral energy is proportional to the wave number to an arbitrary power. The specific case of power 2, which follows from the Saffman invariant, is discussed in detail and is later shown to best describe experimental data. For the spectral energy density in the inertial range we apply both the Kolmogorov -5/3 law, E(k)=Cɛ2/3k-5/3, and the refined Kolmogorov law by taking into account intermittency. We show that intermittency affects the energy decay mainly by shifting the position of the virtual origin rather than altering the power law of the energy decay. Additionally, the spectrum is naturally truncated due to the size of the wind tunnel test section, as eddies larger than the physical size of the system cannot exist. We discuss effects associated with the energy-containing length scale saturating at the size of the test section and predict a change in the power law decay of both energy and vorticity. To incorporate viscous corrections to the model, we truncate the spectrum at an effective Kolmogorov wave number kη=γ(ɛ/v3)1/4, where γ is a dimensionless parameter of order unity. We show that as the turbulence decays, viscous corrections gradually become more important and a simple power law can no longer describe the decay. We discuss the final period of decay within the framework of our model, and show that care must be taken to distinguish between the final period of decay and the change of the character of decay due to the saturation of the energy containing length scale. The model is applied to a number of experiments on decaying turbulence. These include the downstream decay of turbulence in

LevelScheme: A level scheme drawing and scientific figure preparation system for Mathematica

Science.gov (United States)

Caprio, M. A.

2005-09-01

LevelScheme is a scientific figure preparation system for Mathematica. The main emphasis is upon the construction of level schemes, or level energy diagrams, as used in nuclear, atomic, molecular, and hadronic physics. LevelScheme also provides a general infrastructure for the preparation of publication-quality figures, including support for multipanel and inset plotting, customizable tick mark generation, and various drawing and labeling tasks. Coupled with Mathematica's plotting functions and powerful programming language, LevelScheme provides a flexible system for the creation of figures combining diagrams, mathematical plots, and data plots. Program summaryTitle of program:LevelScheme Catalogue identifier:ADVZ Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVZ Operating systems:Any which supports Mathematica; tested under Microsoft Windows XP, Macintosh OS X, and Linux Programming language used:Mathematica 4 Number of bytes in distributed program, including test and documentation:3 051 807 Distribution format:tar.gz Nature of problem:Creation of level scheme diagrams. Creation of publication-quality multipart figures incorporating diagrams and plots. Method of solution:A set of Mathematica packages has been developed, providing a library of level scheme drawing objects, tools for figure construction and labeling, and control code for producing the graphics.

7 CFR 51.490 - Decay.

Science.gov (United States)

2010-01-01

... FRESH FRUITS, VEGETABLES AND OTHER PRODUCTS 1,2 (INSPECTION, CERTIFICATION, AND STANDARDS) United States Standards for Grades of Cantaloups 1 Definitions § 51.490 Decay. Decay means breakdown, disintegration or...

D meson hadronic decays at CLEO-c

Energy Technology Data Exchange (ETDEWEB)

Yang, Fan; /Fermilab

2011-01-01

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

CP-violation in B-decays and B-decay properties at ATLAS experiment

CERN Document Server

Smizanska, Maria; The ATLAS collaboration

2015-01-01

ATLAS has a wide programme to study the production cross section and decay properties of particles with beauty, as well as charmonium and bottomonium states. The main part of the talk will discuss the ATLAS full Run-1 analysis of mixing and CP violation in the decay of Bs meson to J/psi Phi, observed in the final state mu+mu-K+K-. The different amplitudes contributing to the process are studied through the time dependence of the angular distribution, and the average lifetime and lifetime difference between the two eigenstate BH and BL, and of the CP violating phase phi_s are extracted. The presentation will also cover selected latest ATLAS studies in the field of B-hadron decay properties.

CP violation in B decays

International Nuclear Information System (INIS)

Kayser, B.

1990-01-01

The study of CP-violating effects in B decays will be a good test of whether CP violation is caused by the known weak interaction. If this is its origin, then large, cleanly-predicted CP-violating effects are expected in certain neutral B decays to hadronic CP eigenstates. The phenomenology of CP violation in the B system is reviewed, and the genesis of these large effects is explained. In this it is shown that large, cleanly-predicted effects are also expected in some decays to states which are not CP eigenstates. The combined study of the latter decays and those to CP eigenstates may make it possible to obtain a statistically-significant CP-violating signal with fewer B mesons that would otherwise be required

Searching for displaced Higgs boson decays

Science.gov (United States)

Csáki, Csaba; Kuflik, Eric; Lombardo, Salvator; Slone, Oren

2015-10-01

We study a simplified model of the Standard Model (SM) Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs boson decays below 10 cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at √{s }=13 TeV . With 20 fb-1 of data, we find that Higgs branching ratios down to 2 ×1 0-4 can be probed for centimeter decay lengths.

Field-Reversed Configuration Formation Scheme Utilizing a Spheromak and Solenoid Induction

International Nuclear Information System (INIS)

Gerhardt, S.P.; Belova, E.V.; Yamada, M.; Ji, H.; Ren, Y.; McGeehan, B.; Inomoto, M.

2008-01-01

A new field-reversed configuration (FRC) formation technique is described, where a spheromak transitions to a FRC with inductive current drive. The transition is accomplished only in argon and krypton plasmas, where low-n kink modes are suppressed; spheromaks with a lighter majority species, such as neon and helium, either display a terminal tilt-mode, or an n=2 kink instability, both resulting in discharge termination. The stability of argon and krypton plasmas through the transition is attributed to the rapid magnetic diffusion of the currents that drive the kink-instability. The decay of helicity during the transition is consistent with that expected from resistivity. This observation indicates a new scheme to form a FRC plasma, provided stability to low-n modes is maintained, as well as a unique situation where the FRC is a preferred state

Scheme for generating the singlet state of three atoms trapped in distant cavities coupled by optical fibers

Energy Technology Data Exchange (ETDEWEB)

Wang, Dong-Yang [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wen, Jing-Ji [College of Foundation Science, Harbin University of Commerce, Harbin, Heilongjiang 150028 (China); Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wang, Hong-Fu, E-mail: hfwang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhu, Ai-Dong [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhang, Shou, E-mail: szhang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China)

2015-09-15

An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.

Search for proton decay: introduction

International Nuclear Information System (INIS)

Goldhaber, M.

1984-01-01

In interpreting contained events observed in various proton decay detectors one can sometimes postulate, though usually not unambiguously, a potential decay mode of the proton, called a candidate. It is called a candidate, because for any individual event it is not possible to exclude the possibility that it is instead due to cosmic ray background, chiefly atmospheric neutrinos. Some consistency checks are proposed which could help establish proton decay, if it does occur in the presently accessible lifetime window

Beta-decay study of T{sub z}=-2 proton-rich nucleus {sup 24}Si

Energy Technology Data Exchange (ETDEWEB)

Ichikawa, Y.; Iwasaki, H.; Nakao, T.; Ong, H.J.; Onishi, T.K.; Suzuki, D.; Suzuki, H.; Suzuki, M.K. [University of Tokyo, Department of Physics, Tokyo (Japan); Kubo, T.; Aoi, N.; Fukuda, N.; Motobayashi, T.; Yamada, K.N.; Sakurai, H. [RIKEN, RIKEN Nishina Center, Saitama (Japan); Banerjee, V.; Chakrabarti, A. [Variable Energy Cyclotron Centre, Kolkata (India); Kubono, S.; Yamaguchi, H. [University of Tokyo, Center for Nuclear Study, Tokyo (Japan); Nakabayashi, T.; Nakamura, T.; Okumura, T. [Tokyo Institute of Technology, Department of Physics, Tokyo (Japan); Teranishi, T. [Kyushu University, Department of Physics, Fukuoka (Japan)

2009-12-15

{beta} -decay spectroscopy on a T{sub z}=-2 proton-rich nucleus {sup 24}Si was performed. The decay scheme of {sup 24}Si was reconstructed by the {beta} -delayed {gamma} -ray and proton measurements. Two {beta} branches to the bound 1{sub 1}{sup +} and 1{sub 2}{sup +} states in {sup 24}Al were observed for the first time. The observation of the allowed transition firmly established the spin-parity assignment for the 1{sub 2}{sup +} states. The branching ratios to the 1{sub 1}{sup +} and 1{sub 2}{sup +} states were determined to be 31(4)% and 23.9(15)%, respectively. The branching ratios to three unbound states in {sup 24}Al including a new level at 6.735MeV were also determined for the first time. The level structure of {sup 24}Al was compared with its mirror nucleus {sup 24}Na. The Thomas-Ehrman shift on the 1{sub 2}{sup +} state indicates s -wave dominance in the state as well as a characteristic behavior of the weakly bound s-wave proton in {sup 24}Al. (orig.)

Radiative decays of B mesons at LHCb

CERN Document Server

Soomro, Fatima; Golutvin, Andrei

2011-01-01

This thesis is dedicated to the study of radiative decays of $B$ mesons at LHC$b$. At quark level, such decays are a $b\\to s\\gamma$ transition and take place via a penguin loop and are sensitive to virtual contribution of New Physics, which can be indicated by an increase in the decay rates. These decays also offer the possibility to test the V-A structure of the Standard Model coupling in the processes mediated by loop penguin diagrams. In the decay $B_s \\to \\phi\\gamma$, New Physics contribution can be probed by measuring the polarization of the photon in this decay. Systematic effects in the proper time reconstruction of the $B_s$ in $B_s \\to \\phi\\gamma$ can bias the photon polarization measurement in this decay, which will reduce the sensitivity on the relevant New Physics parameter. The author studied those effects and developed ideas to calibrate them using $B_d\\to K^{*}\\gamma$ and $B_s\\to J/\\psi\\phi$ decays as control channels. These studies are mostly Monte Carlo based due to a relatively small data ...

Vacancy decay in endohedral atoms

International Nuclear Information System (INIS)

Amusia, M. Ya.; Baltenkov, A. S.

2006-01-01

It is demonstrated that the fullerene shell dramatically affects the radiative and Auger vacancy decay of an endohedral atom A-C 60 . The collectivized electrons of the C 60 shell add new possibilities for radiative and nonradiative decays similar to that in ordinary atoms where the vacancies in the initial and final state almost always belong to different subshells. It is shown that the smallness of the atomic shell radii as compared to that of the fullerene shell provides an opportunity to derive the simple formulas for the probabilities of the electron transitions. It is shown that the radiative and Auger (or Koster-Kronig) widths of the vacancy decay due to electron transition in the atom A in A-C 60 acquire an additional factor that can be expressed via the polarizability of the C 60 at transition energy. It is demonstrated that due to an opening of the nonradiative decay channel for vacancies in subvalent subshells the decay probability increases by five to six orders of magnitude

CRBRP decay heat removal systems

International Nuclear Information System (INIS)

Hottel, R.E.; Louison, R.; Boardman, C.E.; Kiley, M.J.

1977-01-01

The Decay Heat Removal Systems for the Clinch River Breeder Reactor Plant (CRBRP) are designed to adequately remove sensible and decay heat from the reactor following normal shutdown, operational occurrences, and postulated accidents on both a short term and a long term basis. The Decay Heat Removal Systems are composed of the Main Heat Transport System, the Main Condenser and Feedwater System, the Steam Generator Auxiliary Heat Removal System (SGAHRS), and the Direct Heat Removal Service (DHRS). The overall design of the CRBRP Decay Heat Removal Systems and the operation under normal and off-normal conditions is examined. The redundancies of the system design, such as the four decay heat removal paths, the emergency diesel power supplies, and the auxiliary feedwater pumps, and the diversities of the design such as forced circulation/natural circulation and AC Power/DC Power are presented. In addition to overall design and system capabilities, the detailed designs for the Protected Air Cooled Condensers (PACC) and the Air Blast Heat Exchangers (ABHX) are presented

Decay modes of two repulsively interacting bosons

International Nuclear Information System (INIS)

Kim, Sungyun; Brand, Joachim

2011-01-01

We study the decay of two repulsively interacting bosons tunnelling through a delta potential barrier by a direct numerical solution of the time-dependent Schroedinger equation. The solutions are analysed according to the regions of particle presence: both particles inside the trap (in-in), one particle in and one particle out (in-out) and both particles outside (out-out). It is shown that the in-in probability is dominated by the exponential decay, and its decay rate is predicted very well from outgoing boundary conditions. Up to a certain range of interaction strength, the decay of in-out probability is dominated by the single-particle decay mode. The decay mechanisms are adequately described by simple models.

The weak decay of helium hypernuclei

Energy Technology Data Exchange (ETDEWEB)

Athanas, Michael J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States)

1992-08-01

A Λ hyperon replaces a neutron in a nucleus to form a hypernucleus via the ^AX(K^-, π^-) $A\\atop{Λ}$X reaction at 750 MeV/c (Brookhaven Experiment 788). The free Λ decay rates Γ(Λ → pπ^-) and Γ(Λ → nπ⁰) are diminished due to Pauli blocking; but a non-mesonic decay mode, nucleon stimulated decay NΛ → Nn, is present and is detected via the energetic decay nucleon(s) (~ 400MeV/c). Measurements of the various hypernuclear decay rates Γ(Λ → pπ^-), Γ(Λ → nπ⁰) and Γ(Λn → nn) provides insight into the strong modification of the weak interaction such as the baryon-baryon ΔI ={1/2} rule. The hypernuclear state is isolated by momentum analysis of (K^-, π^-) target reaction. Out-of-beam large volume scintillation detectors and tracking chambers axe used to make particle identification of the hypernuclear decay products by time-of-flight, dE/dx, and range. The kinetic energy of the decay neutrons are measured by time of flight using the large volume 100 element neutron detector system. The hypernuclear lifetime is directly measured using precision scintillator counters and tracking chambers. Measurements of the various decay rates as well as the total lifetime are discussed for $4\\atop{Λ}$He.

Charmed-B decays at BaBar

International Nuclear Information System (INIS)

Tisserand, Vincent

2004-01-01

We present recent results on charmed-B decays using data collected by the BaBaR experiment at the PEP-II storage ring. This report is subdivided in 3 parts. In a first step, we present preliminary results on the measurement of the branching fractions of seven color-suppressed anti B 0 -meson decays into D (*)0 π 0 , D (*)0 η, D (*)0 ω, and D 0 η ' . Then we discuss the preliminary measurement of the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B - →D 0 K - )/B(B - →D 0 π - ), where the D 0 is possibly reconstructed in the CP-even π - π + and K - K + modes. For the D 0 decays into CP-eigenstates, a search for a direct CP asymmetry is performed. For the same category of decay processes, we show a precise preliminary measurement of both the branching fraction of B - decaying to D *0 K *- and of the fraction of longitudinal polarization in this decay. Finally, we present a study where the 22 possible B decays to anti D (*) D * K are reconstructed exclusively. The branching fractions of the anti B 0 and of the B + to anti D (*) D (*) K are presented and a search for decays B→anti D (*) D sJ + (→D (*)0 K + ), where the D sJ + represents the orbitally excited D s states, is also discussed. (orig.)

Packet reversed packet combining scheme

International Nuclear Information System (INIS)

Bhunia, C.T.

2006-07-01

The packet combining scheme is a well defined simple error correction scheme with erroneous copies at the receiver. It offers higher throughput combined with ARQ protocols in networks than that of basic ARQ protocols. But packet combining scheme fails to correct errors when the errors occur in the same bit locations of two erroneous copies. In the present work, we propose a scheme that will correct error if the errors occur at the same bit location of the erroneous copies. The proposed scheme when combined with ARQ protocol will offer higher throughput. (author)

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).

Higgs decays and brane gravi-vectors

International Nuclear Information System (INIS)

Clark, T. E.; Liu Boyang; Love, S. T.; Xiong, C.; Veldhuis, T. ter

2008-01-01

Higgs boson decays in flexible brane world models with stable, massive gravi-vectors are considered. Such vectors couple bilinearly to the standard model fields through either the standard model energy-momentum tensor, the weak hypercharge field strength, or the Higgs scalar. The role of the coupling involving the extrinsic curvature is highlighted. It is found that within the presently allowed parameter space, the decay rate of the Higgs into two gravi-vectors (which would appear as an invisible Higgs decay) can be comparable to the rate for any of the standard model decay modes.

Simulation of branched serial first-order decay of atrazine and metabolites in adapted and nonadapted soils

Science.gov (United States)

Webb, Richard M.; Sandstrom, Mark W.; Jason L. Krutz,; Dale L. Shaner,

2011-01-01

In the present study a branched serial first-order decay (BSFOD) model is presented and used to derive transformation rates describing the decay of a common herbicide, atrazine, and its metabolites observed in unsaturated soils adapted to previous atrazine applications and in soils with no history of atrazine applications. Calibration of BSFOD models for soils throughout the country can reduce the uncertainty, relative to that of traditional models, in predicting the fate and transport of pesticides and their metabolites and thus support improved agricultural management schemes for reducing threats to the environment. Results from application of the BSFOD model to better understand the degradation of atrazine supports two previously reported conclusions: atrazine (6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine) and its primary metabolites are less persistent in adapted soils than in nonadapted soils; and hydroxyatrazine was the dominant primary metabolite in most of the soils tested. In addition, a method to simulate BSFOD in a one-dimensional solute-transport unsaturated zone model is also presented.

Probing the N = Z Line via β Decay

International Nuclear Information System (INIS)

Markku Oinonen

1999-01-01

This contribution reports several beta-decay studies performed at ISOLDE On-Line Mass Separator at CERN recently for nuclei close to N = Z line. Beta decay of 58 Zn provides a possibility to compare Gamow-Teller strength extracted from complementary beta-decay studies and charge-exchange reactions. Measurement on beta-decay half-life of 70 Kr shows importance of experimental information in modeling the path of the astrophysical rp process. Decay of 71 Kr is an example of a mirror beta decay and extends the systematics of these particular decays towards highly deformed region close to A = 80

103Pd decay

International Nuclear Information System (INIS)

Belyavenko, V.S.; Borozenets, G.P.; Vishnevskij, I.N.; Zheltonozhskij, V.A.

1986-01-01

103 Pd decay in different chemical states has been investigated. The change of the partial half-life period equal to 0.67±0.15% has been detected. The γ-spectrum has been measured to a high precision. The new data have been obtained on population probabilities of 103 Rh excited states and the total energy of decay for 103 Pd has been determined to a high precision (543.0±0.8). The values of log ft have been determined

The decay width of stringy hadrons

Science.gov (United States)

Sonnenschein, Jacob; Weissman, Dorin

2018-02-01

In this paper we further develop a string model of hadrons by computing their strong decay widths and comparing them to experiment. The main decay mechanism is that of a string splitting into two strings. The corresponding total decay width behaves as Γ = π/2 ATL where T and L are the tension and length of the string and A is a dimensionless universal constant. We show that this result holds for a bosonic string not only in the critical dimension. The partial width of a given decay mode is given by Γi / Γ =Φi exp ⁡ (- 2 πCmsep2 / T) where Φi is a phase space factor, msep is the mass of the "quark" and "antiquark" created at the splitting point, and C is a dimensionless coefficient close to unity. Based on the spectra of hadrons we observe that their (modified) Regge trajectories are characterized by a negative intercept. This implies a repulsive Casimir force that gives the string a "zero point length". We fit the theoretical decay width to experimental data for mesons on the trajectories of ρ, ω, π, η, K*, ϕ, D, and Ds*, and of the baryons N, Δ, Λ, and Σ. We examine both the linearity in L and the exponential suppression factor. The linearity was found to agree with the data well for mesons but less for baryons. The extracted coefficient for mesons A = 0.095 ± 0.015 is indeed quite universal. The exponential suppression was applied to both strong and radiative decays. We discuss the relation with string fragmentation and jet formation. We extract the quark-diquark structure of baryons from their decays. A stringy mechanism for Zweig suppressed decays of quarkonia is proposed and is shown to reproduce the decay width of ϒ states. The dependence of the width on spin and flavor symmetry is discussed. We further apply this model to the decays of glueballs and exotic hadrons.

Decay of superdeformed bands

International Nuclear Information System (INIS)

Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

1995-01-01

One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

Rare B-decays in the standard model

International Nuclear Information System (INIS)

Ali, A.; Greub, C.; Mannel, T.

1993-02-01