Bremsstrahlung in $\\alpha$ Decay
Takigawa, N; Hagino, K; Ono, A; Brink, D M
1999-01-01
A quantum mechanical analysis of the bremsstrahlung in $\\alpha$ decay of $^{210}$Po is performed in close reference to a semiclassical theory. We clarify the contribution from the tunneling, mixed, outside barrier regions and from the wall of the inner potential well to the final spectral distribution, and discuss their interplay. We also comment on the validity of semiclassical calculations, and the possibility to eliminate the ambiguity in the nuclear potential between the alpha particle and daughter nucleus using the bremsstrahlung spectrum.
Andreev, Andrei; Antalic, S; Ackermann, D.; Bianco, L.; Franchoo, S.; S. Heinz; F. P. Hessberger; Hofmann, S.; Huyse, Marc; Kojouharov, I.; Kindler, B.; Lommel, B.; Mann, R.; Nishio, K; R.D.Page
2009-01-01
Detailed alpha-decay studies of the neutron-deficient isotope At-194 have been performed in the complete fusion reaction Fe-56+Pr-141 -> At-194+3n at the velocity filter SHIP. Two alpha-decaying isomeric states with half-lives of T-1/2(At-194(m1))=310(8) ms and T-1/2(At-194(m2))=253(10) ms were identified in this nucleus. Their complex decays to the states in the daughter nucleus Bi-190 are discussed in the article. We propose that similar to the case of the neighboring At-191,At-192,At-193,A...
Unified model for alpha-decay and alpha-capture
A unified model for alpha-decay and alpha-capture is discussed. Simultaneously the half-lives for alpha-transition between ground states as well as ground and excited states and alpha-capture cross-sections by spherical magic or near-magic nuclei are well described in the framework of this model. Using these data the alpha-nucleus potential is obtained. The simple empirical relations for handy evaluation of the half-lives for alpha-transition, which take into account both the angular momentum and parity of alpha-transition, are presented
Alpha decay property of Pb parent
In this work, the half-lives of alpha decay have been calculated from 182-210Pb nuclei, both in two sphere approximation and taking care the deformation effects and compared with the available theoretical and experimental data
Alpha decay favoured isotopes of some superheavy nuclei: Spontaneous fission versus alpha decay
Kiren, O V; Bubbly, S G
2013-01-01
Spontaneous fission and alpha decay are the main decay modes for superheavy nuclei. The superheavy nuclei which have small alpha decay half-life compared to spontaneous fission half-life will survive fission and can be detected in the laboratory through alpha decay. We have studied the alpha decay half-life and spontaneous half-life of some superheavy elements in the atomic range Z = 100-130. Spontaneous fission half-lives of superheavy nuclei have been calculated using the phenomenological formula and the alpha decay half-lives using Viola-Seaborg-Sobiczewski formula (Sobiczewski et al. 1989), semi empirical relation of Brown (1992) and formula based on generalized liquid drop model proposed by Dasgupta-Schubert and Reyes (2007). The results are reported here.
Radially anisotropic systems with $r^{-\\alpha}$ forces: equilibrium states
Di Cintio, Pierfrancesco; Nipoti, Carlo
2015-01-01
We continue the study of collisionless systems governed by additive $r^{-\\alpha}$ interparticle forces by focusing on the influence of the force exponent $\\alpha$ on radial orbital anisotropy. In this preparatory work we construct the radially anisotropic Osipkov-Merritt phase-space distribution functions for self-consistent spherical Hernquist models with $r^{-\\alpha}$ forces and $1\\leq\\alpha<3$. The resulting systems are isotropic at the center and increasingly dominated by radial orbits at radii larger than the anisotropy radius $r_a$. For radially anisotropic models we determine the minimum value of the anisotropy radius $r_{ac}$ as a function of $\\alpha$ for phase-space consistency (such that the phase-space distribution function is nowhere negative for $r_a\\geq r_{ac}$). We find that $r_{ac}$ decreases for decreasing $\\alpha$, and that the amount of kinetic energy that can be stored in the radial direction relative to that stored in the tangential directions for marginally consistent models increases...
Alpha decay chain of 292116 nucleus
Study of superheavy nuclides is of current interest for theoretical physicists as well experimentalists. The present work describes the alpha decay chain of 292116 terminating at 224Pb with corresponding half-lives. Some of these nuclides are reportedly superdeformed but yet stable
Single particle level scheme for alpha decay
The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)
Alpha Decay, Shell Structure, and New Elements
PENZhong-Zhou; TAIFei; SHENWen-Qing
2003-01-01
We systematically analyze the experimental data of alpha decay in even-even heavy nuclei far from stability and find that the Geiger-Nuttall law brea~s for an isotopic chain when its neutron number is across a marc number or there is a deformed subshell. This break can be used to identify new magic numbers of superheavy nuclei. It is also discovered that there is a new linear relation between the logarithm of half-life and the reciprocal of the square root of decay energy for N = 126 and N = 152 isotones. It could be a new law of alpha decay for nuclei with magic neutron numbers but the physics behind it is to be explored. The significance of these researches for the search of new elements is discussed.
211 Po alpha decay level scheme
The fine structure of alpha decay was discovered by Rosenblum in 1929 by measuring the range of the emitted particle in the air. Usually, attempts to investigate this phenomenon were effected theoretically by calculating the overlaps between the wave function of the parent and the antisymmetric product between the wave functions of the nascent fragments for different configurations after the scission. However, quantitatively this phenomenon was not explained rigorously. In earlier papers, a theory based on the Landau--Zener effect was developed in order to describe quantitatively the cluster decay fine structure phenomenon. It was claimed that the same effect can also direct the fine structure in the case of alpha decay. It was also evidenced that the fine structure can be explained as the promotion of the unpaired nucleon on upper levels belonging to the daughter during the decay process in the field created by the emitted nascent fragment. In this context, the first step in the construction of such a theory for alpha decay is to develop a two-centre diagram of the levels during the whole decay process beginning with the levels of the parent nucleus, following the energetic variations of these levels up to the final configuration given by the separated daughter and alpha particle. Of course, in our representation it is only intended to treat the alpha cluster with a smooth potential in order to estimate the influence of the emitted particle on the daughter levels during the decay and it is not assumed that the oscillator well is appropriate for the description of an alpha nucleus. The Landau-Zener promotion mechanism takes place between levels belonging to the nascent heavy nucleus, so that only the influence of the potential attributed to the alpha particle is taken into consideration. The level scheme is plotted for a nuclear shape parametrisation given by two intersected spheres of different radii as described. The parent and the daughter do not have pronounced
Alpha Decay, Shell Structure, and New Elements
REN Zhong-Zhou; TAI Fei; SHEN Wen-Qing
2003-01-01
We systematically analyze the experimental data of alpha decay in even-even heavy nuclei far from stabilityand find that the Geiger-Nuttall law breaks for an isotopic chain when its neutron number is across a magic numberor there is a deformed subshell. This break can be used to identify new magic numbers of superheavy nuclei. It is alsodiscovered that there is a new linear relation between the logarithm of half-life and the reciprocal of the square root ofdecay energy for N = 126 and N = 152 isotones. It could be a new law of alpha decay for nuclei with magic neutronnumbers but the physics behind it is to be explored. The significance of these researches for the search of new elementsis discussed.
Davids, C.N.; Henderson, D.J.; Hermann, R. [and others
1995-08-01
The {alpha}-decay energy of {sup 181}Pb was measured as 7211(10) keV and 7044(15). In the first study the isotope was produced in {sup 90}Zr bombardments of {sup 94}Mo and, after traversing a velocity filter, implanted in a position-sensitive Si detector; no half life for {sup 181}Pb was reported. In the second study the isotope was produced in {sup 40}Ca bombardments of {sup 144}Sm and transported to a position in front of a Si(Au) surface barrier detector with a fast He-gas-jet capillary system; an estimate of 50 ms was determined for the {sup 181}Pb half life. Recently we investigated {sup 181}Pb {alpha} decay at ATLAS as part of a survey experiment in which a l-pnA beam of 400-MeV {sup 92}Mo was used to irradiate targets of {sup 89}Y, {sup 90,92,94}Zr, and {sup 92}Mo to examine yields for one- and two-nucleon evaporation products from symmetric cold-fusion reactions. Recoiling nuclei of interest were passed through the Fragment Mass Analyzer and implanted in a double-sided silicon strip detector for {alpha}-particle assay. With the {sup 90}Zr target we observed a group at 7065(20) keV which was correlated with A = 181 recoils and had a half life of 45(20) ms. Our new results for {sup 181}Pb therefore agreed with those of the second study. There was no indication in the {sup 90}Zr + {sup 92}Mo data of the 7211(10)-keV {alpha} particles seen by Keller et al. The interested reader is referred to the 1993 atomic mass evaluation wherein the input {alpha}-decay energies and resultant masses of the light Pb isotopes (including {sup 181}Pb) are discussed.
Calculation of nuclear radius using alpha decay
Using a Quantum Theory approach for the Alpha-Decay process, a formula is deduced for determination of the nuclear radius of the s-state, that is, a nuclear model with a spherical shell. The hypothesis that it is possible to individualize the alpha particle and the daughter nucleus at the moment of the alpha particle emission is considered. In considered in these conditions, the treatment of a two body problem considered as point particles, repelling each other by Coulomb's Law. Using the new values of the fundamental physical constants, experimentally determinated, by substitution of their numerical values in the proposed, new values of nuclear radii are obtained. These values are compared with those found in the literature. (author)
alpha-nucleus potentials, alpha-decay half-lives, and shell closures for superheavy nuclei
Mohr, Peter
2006-01-01
Systematic alpha-nucleus folding potentials are used to analyze alpha-decay half-lives of superheavy nuclei. Preformation factors of about several per cent are found for all nuclei under study. The systematic behavior of the preformation factors and the volume integrals of the potentials allows to predict alpha-decay energies and half-lives for unknown nuclei. Shell closures can be determined from measured alpha-decay energies using the discontinuity of the volume integral at shell closures. ...
An anisotropic universe due to dimension-changing vacuum decay
Scargill, James H C
2015-01-01
In this paper we consider the question of observational signatures of a false vacuum decay event in the early universe followed by a period of inflation; in particular, motivated by the string landscape, we consider decays in which the parent vacuum has a smaller number of large dimensions than the current vacuum, which leads to an anisotropic universe. We go beyond previous studies, and examine the effects on the CMB temperature and polarisation power spectra, due to both scalar and tensor modes, and consider not only late-time effects but also the full cosmological perturbation theory at early times. We find that whilst the scalar mode behaves as one would expect, and the effects of anisotropy at early times are sub-dominant to the late-time effects already studied, for the tensor modes in fact the the early-time effects grow with multipole and can become much larger than one would expect, even dominating over the late-time effects. Thus these effects should be included if one is looking for such a signal i...
Random numbers spring from alpha decay
Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Clark, N.A.; Tyler, S.A.
1980-05-01
Congruential random number generators, which are widely used in Monte Carlo simulations, are deficient in that the number they generate are concentrated in a relatively small number of hyperplanes. While this deficiency may not be a limitation in small Monte Carlo studies involving a few variables, it introduces a significant bias in large simulations requiring high resolution. This bias was recognized and assessed during preparations for an accident analysis study of nuclear power plants. This report describes a random number device based on the radioactive decay of alpha particles from a /sup 235/U source in a high-resolution gas proportional counter. The signals were fed to a 4096-channel analyzer and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts (0 for an even count and 1 for an odd count) were then assembled in sequence to form 31-bit binary random numbers and transcribed to a magnetic tape. This cycle was repeated as many times as were necessary to create 3 million random numbers. The frequency distribution of counts from the present device conforms to the Brockwell-Moyal distribution, which takes into account the dead time of the counter (both the dead time and decay constant of the underlying Poisson process were estimated). Analysis of the count data and tests of randomness on a sample set of the 31-bit binary numbers indicate that this random number device is a highly reliable source of truly random numbers. Its use is, therefore, recommended in Monte Carlo simulations for which the congruential pseudorandom number generators are found to be inadequate. 6 figures, 5 tables.
Random numbers spring from alpha decay
Congruential random number generators, which are widely used in Monte Carlo simulations, are deficient in that the number they generate are concentrated in a relatively small number of hyperplanes. While this deficiency may not be a limitation in small Monte Carlo studies involving a few variables, it introduces a significant bias in large simulations requiring high resolution. This bias was recognized and assessed during preparations for an accident analysis study of nuclear power plants. This report describes a random number device based on the radioactive decay of alpha particles from a 235U source in a high-resolution gas proportional counter. The signals were fed to a 4096-channel analyzer and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts (0 for an even count and 1 for an odd count) were then assembled in sequence to form 31-bit binary random numbers and transcribed to a magnetic tape. This cycle was repeated as many times as were necessary to create 3 million random numbers. The frequency distribution of counts from the present device conforms to the Brockwell-Moyal distribution, which takes into account the dead time of the counter (both the dead time and decay constant of the underlying Poisson process were estimated). Analysis of the count data and tests of randomness on a sample set of the 31-bit binary numbers indicate that this random number device is a highly reliable source of truly random numbers. Its use is, therefore, recommended in Monte Carlo simulations for which the congruential pseudorandom number generators are found to be inadequate. 6 figures, 5 tables
Sensitivity of alpha-decay to the real alpha-nucleus potential
The information which can be obtained from studies of low energy alpha-particle scattering from heavy nuclei and from alpha-decay is discussed. The sensitivity of calculated widths and lifetimes for alpha-decay to the real nuclear potential is examined in detail using a formalism based on the unified theory of nuclear reactions. It is shown that a combined study of alpha-decay and alpha-particle scattering at energies near the Coulomb barrier should give a very precise determination of the barrier height and radius, although there is a more uniquely defined separation distance some way beyond the barrier. (orig.)
HOLDEN, H.E.
2003-08-08
In his review of radionuclides for dating purposes, Roth noted that there were a large number of nuclides, normally considered ''stable'' but which are radioactive with a very long half-life. Roth suggested that I review the data on the half-life values of these long-lived nuclides for the 2001 Atomic Weights Commission meeting in Brisbane. I provided a report, BNL-NCS-68377, to fulfill Roth's request. Peiser has now made a similar suggestion that I review these data for our next Commission meeting in Ottawa for their possible inclusion in our Tables. These half-life values for long-lived nuclides include those due to various decay modes, {alpha}-decay, {beta}-decay, electron capture decay, {beta}{beta}-decay, proton decay and spontaneous fission decay. This data review (post Brisbane) provides an update to the recommendation of the 2001 review.
Alpha decay by cubic plus Yukawa plus exponential model
The half life of alpha decay in some nuclei by using cubic plus Yukawa plus exponential model (CYCM) of Shanmugam and Kamalaharan is calculated in this project and compared with the available experimental values
New experimental limits on the alpha decays of lead isotopes
Beeman, J W; Cardani, L; Casali, N; Di Domizio, S; Fiorini, E; Gironi, L; Nagorny, S S; Nisi, S; Orio, F; Pattavina, L; Pessina, G; Piperno, G; Pirro, S; Previtali, E; Rusconi, C; Tomei, C; Vignati, M
2013-01-01
For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg.
$\\alpha_{s}$ from the (revised) ALEPH data for $\\tau$ decay
Boito, Diogo; Maltman, Kim; Osborne, James; Peris, Santiago
2014-01-01
We present a new analysis of $\\alpha_s$ from hadronic $\\tau$ decays based on the recently revised ALEPH data. The analysis is based on a strategy which we previously applied to the OPAL data. We critically compare our strategy to the one traditionally used and comment on the main differences. Our analysis yields the values $\\alpha_s(m_\\tau^2)=0.296\\pm 0.010$ using fixed-order perturbation theory, and $\\alpha_s(m_\\tau^2)=0.310\\pm 0.014$ using contour-improved perturbation theory. Averaging these values with our previously obtained values from the OPAL data, we find $\\alpha_s(m_\\tau^2)=0.303\\pm 0.009$, respectively, $\\alpha_s(m_\\tau^2)=0.319\\pm 0.012$, as the most reliable results for $\\alpha_s$ from $\\tau$ decays currently available.
Unified approach to alpha decay calculations
C S Shastry; S M Mahadevan; K Aditya
2014-05-01
With the discovery of a large number of superheavy nuclei undergoing decay through emissions, there has been a revival of interest in decay in recent years. In the theoretical study of decay the -nucleus potential, which is the basic input in the study of -nucleus systems, is also being studied using advanced theoretical methods. In the light of these, theWentzel–Kramers–Brillouin (WKB) approximation method often used for the study of decay is critically examined and its limitations are pointed out. At a given energy, the WKB expression uses barrier penetration formula for the determination of the transmission coefficient. This approach utilizes the -nucleus potential only at the barrier region and ignores it elsewhere. In the present era, when one has more precise experimental information on decay parameters and better understanding of -nucleus potential, it is desirable to use a more precise method for the calculation of decay parameters. We describe the analytic -matrix (SM) method which gives a procedure for the calculation of decay energy and mean life in an integrated way by evaluating the resonance pole of the -matrix in the complex momentum or energy plane. We make an illustrative comparative study of WKB and -matrix methods for the determination of decay parameters in a number of superheavy nuclei.
Alpha-decay properties of 261Bh
The isotope 261Bh was produced in the reaction 209Bi(54Cr,2n)261Bh and its α decay has been remeasured. It was found that it populates by an unhindered transition of ∼ 10 MeV an excited level at E* >350 keV in the daughter nucleus 257Db. The latter decays by internal transitions either into the isomeric state or the ground state. A somewhat improved half-life value of T1/2=11.8+3.9-2.4 ms was obtained for 261Bh. The data support the previous assignment of the α activities 257Db (1) and 257Db (2) to the isomer and to the ground state, respectively. No evidence for an isomeric state in 261Bh decaying by α emission was found. Based on the experimental results and theoretical calculations a partial decay scheme of 261Bh including spin and parity assignments of the ground-state and excited levels in the daughter nucleus 257Db populated by the α decay and succeeding internal transitions have been suggested. 261Bh represents so far the heaviest nucleus for which such an attempt has been made. No spontaneous fission (SF) events that could be attributed to 261Bh were observed, resulting in an SF branching bSF*=22 MeV. (orig.)
Order (alpha^2 Gamma, alpha^3 Gamma) Binding Effects in Orthopositronium Decay
Hill, Richard J.; Lepage, G. Peter
2000-01-01
We present a new, simplified analysis of the low-energy electron-positron interaction, and use the resulting effective theory to calculate the binding effects that contribute to the decay rate, Gamma, of orthopositronium, through Order(alpha^3 ln(alpha) Gamma). We express the total decay rate in terms of the annihilation rate for a free electron and positron at threshold, which has just recently been computed to sufficient precision. Our result corrects errors in a previous analysis.
Effective liquid drop description for alpha decay of atomic nuclei
Tavares, O.A.P.; Duarte, S.B. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Rodriguez, O.; Guzman, F. [Instituto Superior de Ciencia y Tecnologia Nuclear (ISCTN), La Habana (Cuba); Goncalves, M. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Garcia, F. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica
1998-06-01
Alpha decay half-lives are presented in the framework of an effective liquid drop model for different combination of mass transfer descriptions and inertia coefficients. Calculated half-life-values for ground-state to ground-state favoured alpha transitions are compared with available, updated experimental data. Results have shown that the present model is very suitable to treat the alpha decay process on equal foot as cluster radioactivity and cold fission processes. Better agreement with the data is found when the sub-set of even-even alpha emitters are considered in the calculation. (author) 44 refs., 5 figs., 3 tabs.; e-mail: telo at ird.gov.br
Fine Structure of 211 Po Alpha Decay
Recently, a theory based on the Landau-Zener effect was developed intending to describe quantitatively the cluster decay fine structure phenomenon. It was claimed that the same promotion effect can also govern the fine structure in the case of α-decay. This formalism intends to explain the fine structure of α-decay by considering single-particle transitions due to the radial and the rotational couplings. The levels with the same good quantum numbers associated to some symmetries of the system cannot in general intersect, but exhibit quasi-crossings, or pseudo-crossings, or avoided level crossings. The system is characterised by an axial symmetry, therefore the good quantum numbers are the projections of the nucleon spin Ω. The radial coupling causes transitions of the unpaired nucleon near the avoided level crossings. True crossings can also be obtained between levels characterized by different quantum numbers. Generally, the rotational coupling has a maximum strength in the vicinity of the true crossings. Transitions due to both couplings are taken into account in order to explain the excitations of the unpaired nucleon. For a tunnelling velocity of 9 x 106 fm/fs, the ratio between the intensity for transitions to the first excited state and to the ground state was found to be 0.0071 and the obtained ratio of the same parameter between the second excited state and the ground state was 0.0062, in good agreement with experimental data. These calculations suggest that the α-decay fine structure phenomenon can be explained quantitatively by describing the decaying system with molecular models and it can be stated that the quantitative characteristics of this phenomenon are ruled by dynamical effects. (author)
Comparison of semiempirical formulae for alpha decay half-lives
The semiempirical relationships given by Froeman, Wapstra et al., Viola and Seaborg, Hornshoj et al., Taagepera and Nurmia, Keller and Munzel for alpha decay half-lives are compared with experimental results and with a new formula derived by the authors form the fission theory of alpha decay in even-even, odd-even, even-odd and odd-odd nuclei. By taking into consideration the shell effects, the new formula allows one to obtain a better agreement with experimental data, even in the neighbourhood of the magic numbers
Energy Decay Laws in Strongly Anisotropic Magnetohydrodynamic Turbulence
We investigate the influence of a uniform magnetic field B0=B0eparallel on energy decay laws in incompressible magnetohydrodynamic (MHD) turbulence. The nonlinear transfer reduction along B0 is included in a model that distinguishes parallel and perpendicular directions, following a phenomenology of Kraichnan. We predict a slowing down of the energy decay due to anisotropy in the limit of strong B0, with distinct power laws for energy decay of shear- and pseudo-Alfven waves. Numerical results from the kinetic equations of Alfven wave turbulence recover these predictions, and MHD numerical results clearly tend to follow them in the lowest perpendicular planes
Cluster radioactivity and alpha decay of superheavy nuclei
The competition of cluster radioactivity and α decay is investigated in the region of superheavy (SH) nuclei with atomic numbers Z = 104 - 124. Calculations of half-lives within analytical super-asymmetrical fission (ASAF) model are performed by using different theoretical mass tables to determine the energy released, Q. For α decay the ASAF calculations are compared with semFIS (semi-empirical fission model). A trend toward shorter half-lives and larger branching ratios relative to alpha decay for heavier SHs was observed
$\\alpha_s$ from the updated ALEPH data for hadronic $\\tau$ decays
Boito, Diogo; Maltman, Kim; Osborne, James; Peris, Santiago
2015-01-01
We extract the strong coupling $\\alpha_s(m_\\tau^2)$ from the recently updated ALEPH non-strange spectral functions obtained from hadronic $\\tau$ decays. We apply a self-consistent analysis method, first tested in the analysis of OPAL data, to extract $\\alpha_s(m_\\tau^2)$ and non-perturbative contributions. The analysis yields $\\alpha_s^{\\rm FO}(m_\\tau^2)=0.296\\pm0.010 $, using Fixed Order Perturbation Theory (FOPT), and $\\alpha^{\\rm CI}_s(m_\\tau^2)= 0.310\\pm0.014$, using Contour Improved Perturbation Theory (CIPT). The weighted average of these results with those previously obtained from OPAL data give $\\alpha_s^{\\rm FO}(m_\\tau^2)=0.303\\pm 0.009$ and $\\alpha_s^{\\rm CI}(m_\\tau^2)=0.319\\pm 0.012$, which gives, after evolution to the $Z$ boson mass scale, $\\alpha^{\\rm FO}_s(m_Z^2)=0.1165\\pm0.0012 $ and $\\alpha_s^{\\rm CI}(m_Z^2)=0.1185\\pm0.0015 $, respectively. We observe that non-perturbative effects limit the accuracy with which $\\alpha_s$ can be extracted from $\\tau$ decay data.
Alpha Decay in the Complex Energy Shell Model
Betan, R Id
2012-01-01
Alpha emission from a nucleus is a fundamental decay process in which the alpha particle formed inside the nucleus tunnels out through the potential barrier. We describe alpha decay of $^{212}$Po and $^{104}$Te by means of the configuration interaction approach. To compute the preformation factor and penetrability, we use the complex-energy shell model with a separable T=1 interaction. The single-particle space is expanded in a Woods-Saxon basis that consists of bound and unbound resonant states. Special attention is paid to the treatment of the norm kernel appearing in the definition of the formation amplitude that guarantees the normalization of the channel function. Without explicitly considering the alpha-cluster component in the wave function of the parent nucleus, we reproduce the experimental alpha-decay width of $^{212}$Po and predict an upper limit of T_{1/2}=5.5x10^{-7} sec for the half-life of $^{104}$Te. The complex-energy shell model in a large valence configuration space is capable of providing ...
Bremsstrahlung during $\\alpha$-decay: quantum multipolar model
Maydanyuk, Sergei P
2008-01-01
In this paper the improved multipolar model of bremsstrahlung accompanied the $\\alpha$-decay is presented. The angular formalism of calculations of the matrix elements, being enough complicated component of the model, is stated in details. A new definition of the angular (differential) probability of the photon emission in the $\\alpha$-decay is proposed where direction of motion of the $\\alpha$-particle outside (with its tunneling inside barrier) is defined on the basis of angular distribution of its spacial wave function. In such approach, the model gives values of the angular probability of the photons emission in absolute scale, without its normalization on experimental data. Effectiveness of the proposed definition and accuracy of the spectra calculations of the bremsstrahlung spectra are analyzed in their comparison with experimental data for the $^{210}{\\rm Po}$, $^{214}{\\rm Po}$, $^{226}{\\rm Ra}$ and $^{244}{\\rm Cm}$ nuclei, and for some other nuclei predictions are performed (in absolute scale). With ...
Decay properties of /sup 186/Pb and the lead alpha-decay rate anomaly
Toth, K.S.; Ellis-Akovali, Y.A.; Bingham, C.R.; Moltz, D.M.; Carter, H.K.; Mlekodaj, R.L.; Spejewski, E.H.; Sousa, D.C.
1984-01-01
Alpha-decay transitions between ground states of doubly-even nuclei are taken to represent unhindered decays. Reduced widths for these s-wave transitions behave in a regular fashion as a function of both neutron and atomic number. They are largest for nuclei two or four particles beyond a closed shell (with sharp minima at the shell) and they then decrease as the next closure is approached. The s-wave widths for /sup 186/ /sup 188/ /sup 190/ /sup 192/Pb, however, have been reported to behave anomalously, i.e., they purportedly increase by a factor of 30 between /sup 186/Pb (N = 104) and /sup 192/Ob (N = 110) instead of decreasing as one nears N = 126. Theoretical calculations have not reproduced this unusual behavior. The (electron-capture (EC) + ..beta../sup +/) strengths were deduced from K x-ray intensities. A number of corrections are involved in such determinations. We undertook the investigation of the (EC + ..beta../sup +/) decay schemes of these neutron-deficient lead isotopes, in conjunction with studies of their ..cap alpha..-decay properties, to obtain more reliable ..cap alpha..-branching ratios. Herein we present new information on /sup 186/Pb and discuss the partial ..cap alpha.. half-lives for /sup 192/Pb, /sup 190/Pb, /sup 188/Pb, and /sup 186/Pb together with ..cap alpha..-decay rates for even-even nuclei with Z greater than or equal to 78.
Alpha-decay properties of 266Bh
The isotope of 266Bh was produced and identified definitely in bombardments of 243Am target with 162 MeV 26Mg ions at HIRFL. Identification was made by observation of correlated α-particle decays between the Bh isotopes and their Db and Lr daughters using a rotating wheel system. The measured α energy for 266Bh is (9.03 ± 0.08) MeV, and this value close to the 9.07 MeV for 266Bh observed in the first chain of element 113 at RIKEN. The half-life of 266Bh is (0.66)-0.26+0.59s. The Qα value derived from this experiment fits well into the general trend in a 'Qα-N systematics' for the isotopes with Z=107. (authors)
Alpha-decay properties of {sup 261}Bh
Hessberger, F.P.; Ackermann, D.; Heinz, S.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R. [Helmholtzzentrum fuer Schwerionenforschung GmbH, GSI, Darmstadt (Germany); Antalic, S. [Comenius University Bratislava, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Hofmann, S. [Helmholtzzentrum fuer Schwerionenforschung GmbH, GSI, Darmstadt (Germany); Goethe-Universitaet Frankfurt, Institut fuer Physik, Frankfurt (Germany)
2010-02-15
The isotope {sup 261}Bh was produced in the reaction {sup 209}Bi({sup 54}Cr,2n){sup 261}Bh and its {alpha} decay has been remeasured. It was found that it populates by an unhindered transition of {approx} 10 MeV an excited level at E{sup *} >350 keV in the daughter nucleus {sup 257}Db. The latter decays by internal transitions either into the isomeric state or the ground state. A somewhat improved half-life value of T{sub 1/2}=11.8{sup +3.9} {sub -2.4} ms was obtained for {sup 261}Bh. The data support the previous assignment of the {alpha} activities {sup 257}Db (1) and {sup 257}Db (2) to the isomer and to the ground state, respectively. No evidence for an isomeric state in {sup 261}Bh decaying by {alpha} emission was found. Based on the experimental results and theoretical calculations a partial decay scheme of {sup 261}Bh including spin and parity assignments of the ground-state and excited levels in the daughter nucleus {sup 257}Db populated by the {alpha} decay and succeeding internal transitions have been suggested. {sup 261}Bh represents so far the heaviest nucleus for which such an attempt has been made. No spontaneous fission (SF) events that could be attributed to {sup 261}Bh were observed, resulting in an SF branching b{sub SF}< 0.05. The measured production cross-section is (64{+-}15) pb at E{sup *}=22 MeV. (orig.)
On surface clustering and Pauli principle effects in alpha decay
The importance of the correct description of nuclear surface region in alpha decay calculations is pointed out. A model is proposed takinq into account explicitly surface clustering and Pauli principle effects which are essential in this region. A method for solving the main integrodifferential equation of the model by using the oscillator shell basis and the Collatz method is worked out. The first numerical results are obtained for nonlocal potential of the atpha particle-daughter nucleus interaction
Thermalization of anisotropic quark–gluon plasma produced by decays of color flux tubes
Kinetic equations are used to study the thermalization of an anisotropic quark–gluon plasma produced by decays of color flux tubes possibly created during the very early stages of relativistic heavy-ion collisions. The decay rates of the initial color tubes are given by the Schwinger formula, while the collision terms are taken in the relaxation time approximation. By connecting the relaxation time with viscosity we analyze production and thermalization processes in the plasma characterized by different values of the ratio of the shear viscosity to entropy density
Simulations of the anisotropic kinetic and magnetic alpha effects
Brandenburg, A
2007-01-01
The validity of a closure called the minimal tau approximation (MTA), is tested in the context of dynamo theory, wherein triple correlations are assumed to provide relaxation of the turbulent electromotive force. Under MTA, the alpha effect in mean field dynamo theory becomes proportional to a relaxation time scale multiplied by the difference between kinetic and current helicities. It is shown that the value of the relaxation time is positive and, in units of the turnover time at the forcing wavenumber, it is of the order of unity. It is quenched by the magnetic field -- roughly independently of the magnetic Reynolds number. However, this independence becomes uncertain at large magnetic Reynolds number. Kinetic and current helicities are shown to be dominated by large scale properties of the flow.
Alpha Decay Width of $^{212}$Po from a quartetting wave function approach
Xu, Chang; Röpke, G; Schuck, P; Funaki, Y; Horiuchi, H; Tohsaki, A; Yamada, T; Zhou, Bo
2015-01-01
A microscopic calculation of $\\alpha$-cluster preformation probability and $\\alpha$ decay width in the typical $\\alpha$ emitter $^{212}$Po is presented. Results are obtained by improving a recent approach to describe $\\alpha$ preformation in $^{212}$Po [Phys. Rev. C 90, 034304 (2014)] implementing four-nucleon correlations (quartetting). Using the actually measured density distribution of the $^{208}$ Pb core, the calculated alpha decay width of $^{212}$Po agrees fairly well with the measured one.
$\\alpha_s$ analyses from hadronic tau decays with OPAL and ALEPH data
Boito, Diogo; Maltman, Kim; Peris, Santiago
2016-01-01
Recently, we extracted the strong coupling, $\\alpha_s(m_\\tau^2)$, from the revised ALEPH data for non-strange hadronic tau decays. Our analysis is based on a method previously used for the determination of the strong coupling from OPAL data. In our strategy, we employ different moments of the spectral functions both with and without pinching, including Duality Violations, in order to obtain fully self-consistent analyses that do not rely on untested assumptions (such as the smallness of higher dimension contributions in the OPE). Here we discuss the $\\alpha_s$ values obtained from the ALEPH and the OPAL data, the robustness of the analysis, as well as non-perturbative contributions from DVs and the OPE. We show that, although the $\\alpha_s$ determination is sound, non-perturbative effects limit the accuracy with which one can extract the strong coupling from tau decay data. Finally, we discuss the compatibility of the data sets and the possibility of a combined analysis.
{alpha}{sub s} from {tau} decays revisited
Boito, D.R. [Institut fuer Theoretische Teilchenphysik und Kosmologie, RWTH Aachen University, D-52074 Aachen (Germany); Cata, O. [Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Arnold Sommerfeld Centre for Theoretical Physics, D-80333 Muenchen (Germany); Golterman, M. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Jamin, M. [ICREA and IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Maltman, K. [Department of Math and Statistics, York University, Toronto, ON M3J 1P3 (Canada); CSSM, University of Adelaide, Adelaide, SA 5005 (Australia); Osborne, J. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Peris, S. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)
2012-04-15
Being a determination at low energies, the analysis of hadronic {tau} decay data provides a rather precise determination of the strong coupling {alpha}{sub s} after evolving the result to M{sub Z}. At such a level of precision, even small non-perturbative effects become relevant for the central value and error. While those effects had been taken into account in the framework of the operator product expansion, contributions going beyond it, so-called duality violations, have previously been neglected. The following investigation fills this gap through a finite-energy sum rule analysis of {tau} decay spectra from the OPAL experiment, including duality violations and performing a consistent fit of all appearing QCD parameters. The resulting values for {alpha}{sub s}(M{sub {tau}}) are 0.307(19) in fixed-order perturbation theory and 0.322(26) in contour-improved perturbation theory, which translates to the n{sub f}=5 values 0.1169(25) and 0.1187(32) at M{sub Z}, respectively.
Lyman-alpha Forest Constraints on Decaying Dark Matter
Wang, Mei-Yu; Peter, Annika H G; Zentner, Andrew R; Purcell, Chris W
2013-01-01
We present an analysis of high-resolution N-body simulations of decaying dark matter cosmologies focusing on the statistical properties of the transmitted Lyman-alpha forest flux in the high-redshift intergalactic medium. In this type of model a dark matter particle decays into a slightly less massive stable dark matter daughter particle and a comparably light particle. The small mass splitting provides a non-relativistic kick velocity V_k to the daughter particle resulting in free-streaming and subsequent damping of small-scale density fluctuations. Current Lyman-alpha forest power spectrum measurements probe comoving scales up to ~ 2-3 h^-1 Mpc at redshifts z ~ 2-4, providing one of the most robust ways to probe cosmological density fluctuations on relatively small scales. The suppression of structure growth due to the free-streaming of dark matter daughter particles also has a significant impact on the neutral hydrogen cloud distribution, which traces the underlying dark matter distribution well at high re...
Alpha decay and nuclear deformation: the case for favoured alpha transitions of even-even emitters
Alpha decay half-life for ground-state to ground-state transitions of 174 even-even alpha emitters has been calculated from a simple, Gamow-like model in which the quadrupole deformation of the product nucleus (assumed to have an ellipsoidal shape) is taken into account. The assumption made is that before tunnelling through a purely Coulomb potential barrier the two-body system oscillates isotropically, thus giving rise to an equivalent, average polar direction θ0 (referred to the symmetry axis of the ellipsoid) for alpha emission. It is shown that the experimental half-life data are much better reproduced by the present description than in the spherical shaped approximation for the daughter nucleus. (author)
Fine structure in the alpha decay of {sup 224} U
Lopez-Martens, A.; Hauschild, K.; Rezynkina, K. [CNRS-IN2P3, CSNSM, Universite Paris Sud, Orsay (France); Dorvaux, O.; Gall, B.; Dechery, F.; Faure, H. [CNRS-IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); Yeremin, A.V.; Chelnokov, M.L.; Chepigin, V.I.; Isaev, A.V.; Izosimov, I.N.; Katrasev, D.E.; Kuznetsov, A.N.; Kuznetsova, A.A.; Malyshev, O.N.; Popeko, A.G.; Sokol, E.A.; Svirikhin, A.I. [JINR, FLNR, Dubna (Russian Federation); Piot, J. [CNRS-IN2P3, GANIL, CEA-DSM, Caen (France); Rubert, J. [CNRS-IN2P3, IPHC, Universite de Strasbourg, Strasbourg (France); CNRS-IN2P3, LPSC, Universite Grenoble-Alpes, Grenoble (France)
2014-08-15
{sup 224}U nuclei were populated in fusion-evaporation reactions using a {sup 206}Pb target and an intense {sup 22}Ne beam. Fusion-evaporation residues were separated by the new separator SHELS at the FLNR, Dubna and implanted into a large-area double-sided silicon strip detector. Position- and time-correlated alpha decays were used to identify evaporation residues. A new α -decay line at 8095(11) keV was observed in this work and assigned as the decay from {sup 224}U to the first excited 2{sup +} in the daughter nucleus {sup 220}Th. Coincident photons were also observed allowing to unambiguously determine the excitation energy of the first excited 2{sup +} state in {sup 220}Th to be 386.5(1) keV and not 373.3(1)keV as previously reported. The half-life of {sup 224}U was measured to be 396(17)μs. (orig.)
A fractional calculus approach to investigate the alpha decay processes
In this study, the nuclear decay equation is taken under consideration by making use of fractional calculus. In this context, the first-order time derivative is changed to a Caputo fractional derivative hence, the resulting equation is the time fractional nuclear decay equation. The solution of this equation is obtained in terms of Mittag–Leffler function which plays an important role to study the non-Markovian feature of physical processes. As an application of this time fractional formalism, alpha decay half-life values have been calculated for Pb, Po, Rn, Ra, Th and U isotopes. Consequently, the theoretical half-life values have been obtained in consistent with the experimental data. The dependence of the order of fractional derivative μ being a measure of fractality of time, on the nuclear structure has been established. In the investigations carried out, we have arrived to the conclusion that for the μ values which are closed to one, where time becomes homogenous and continuous, the shell closure effects are predominant and that the fractional derivative order μ (i.e., fractality of time) and nuclear structure are closely related to each other. (author)
Study of alpha-decay half-lives with deformed, oriented daughter nuclei
In this paper, Coulomb and proximity potential model has been applied to calculate the half-lives of alpha-decay for isotopes around N = Z = 50. Using this model, we investigated the influence of deformation and orientation of daughter nucleus on alpha-decay half-lives. Two orientations (90° and 180°) with quadrupole deformation are applied to study the role of daughter orientation in alpha-decay process. It is found that the deformation and orientation of daughter nucleus affects the alpha-decay half-life and changes the slope and intercept of linear relation between log10(T1/2) and Q-1/2. (author)
A microscopic description for the alpha decay of nuclei using a realistic effective interaction
Basu, D N
2002-01-01
The process of alpha disintegration has been studied theoretically in the framework of a microscopic superasymmetric fission model (MSAFM). The nuclear interaction potential required for the alpha decay process has been calculated by folding in the density distribution functions of the alpha nucleus and the daughter nucleus with a realistic effective interaction. The nuclear microscopic alpha-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently results in a parameter free calculation for the half lives of the alpha decays of nuclei. The model is successful in calculating the half lives of the alpha disintegration processes of nuclei.
Contributions to the study of heavy and superheavy nuclei stability in alpha-decay
Alpha-decay is treated in this work on the complete analogy of transfer reactions by means of nuclear shell models with continuous spectrum nucleons. Certain phenomenologically obtained or microscope evaluated data on low energy interactions between alpha-particles and nuclei, when related to nuclear structure data within the unified theory of nuclear reactions, allow of an improved accuracy in determining the alpha-particle wave function as well as of an estimation of alpha-probabilities in good keeping with experimental ones. The problem of alpha lifetimes thus narrows to the resolution of some homogeneous and inhomogeneous differential equations systems including the optic potential and the alpha formfactors. (author)
Alpha decay as a probe for the structure of neutron-deficient nuclei
Qi, Chong
2016-01-01
The advent of radioactive ion beam facilities and new detector technologies have opened up new possibilities to investigate the radioactive decays of highly unstable nuclei, in particular the proton emission, $\\alpha$ decay and heavy cluster decays from neutron-deficient (or proton-rich) nuclei around the proton drip line. It turns out that these decay measurements can serve as a unique probe for studying the structure of the nuclei involved. On the theoretical side, the development in nuclear many-body theories and supercomputing facilities have also made it possible to simulate the nuclear clusterization and decays from a microscopic and consistent perspective. In this article we would like to review the current status of these structure and decay studies in heavy nuclei, regarding both experimental and theoretical opportunities. We then discuss in detail the recent progress in our understanding of the nuclear $\\alpha$ formation probabilities in heavy nuclei and their indication on the underlying nuclear st...
Ground state properties of the newly discovered nucleus 265Bh and it's alpha decay chain
The properties of the nuclei belonging to the newly discovered alpha-decay chain starting from 265Bh have been studied. The axially deformed relativistic mean field (RMF) calculation with the force TMA and NL-Z2 has been performed in the blocked BCS approximation. Some ground state properties such as the binding energies, deformations, spins and parties, as well as Q-values of the alpha decay for this decay chain have been calculated and compared with known experimental data. Good agreement is observed. The single-particle spectrum of the nucleus 265Bh has been studied. (authors)
Study of rare alpha decays with scintillating bolometers
Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza University of Roma, Roma I-00185 (Italy); INFN, Sezione di Roma, Roma I-00185 (Italy)
2013-08-01
Rare α decays can be studied with an unprecedented sensitivity by means of scintillating bolometers, as these detectors can provide a large source mass as well as an excellent resolution and can disentangle the nature of the interacting particle thanks to the different light yield. As an example of the results that can be obtained with this technique, I report the conclusive test on the identification of {sup 209}Bi decay and the measurement of the half-life of this isotope. In addition, I present a measurement with a PbWO{sub 4} scintillating bolometer, in which the lead isotopes decays were studied.
Alpha-particle momentum distributions from 12C decaying resonances
The computed α particle momentum distributions from the decay of low-lying 12C resonances are shown. The wave function of the decaying fragments is computed by means of the complex scaled hyperspherical adiabatic expansion method. The large-distance part of the wave functions is crucial and has to be accurately calculated. We discuss energy distributions, angular distributions and Dalitz plots for the 4+, 1+ and 4- states of 12C. (author)
Alpha decay properties of heavy and superheavy elements
G M Carmel Vigila Bai; J Umai Parvathiy
2015-01-01
Analysing accurately the lifetimes of -decay chains is an important tool to detect and study the properties of superheavy nuclei. 48Ca is used in the synthesis of superheavy nuclei = 106−118 at Dubna. The experimental work of 48Ca projectiles at Dubna has given an opportunity to study the superheavy element (SHE). Here, the -decay properties for = 106–118 are evaluated using our CYE model and are compared with the available experimental and theoretical values.
Alpha-decay-induced fracturing in zircon: the transition from the crystalline to the metamict state
A natural single crystal of zircon, ZrSiO4, from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 1016 and 0.8 x 1016 alpha-event per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 1016 alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides
Chakoumakos, B C; Murakami, T; Lumpkin, G R; Ewing, R C
1987-06-19
A natural single crystal of zircon, ZrSiO(4,) from Sri Lanka exhibited zonation due to alpha-decay damage. The zones vary in thickness on a scale from one to hundreds of micrometers. The uranium and thorium concentrations vary from zone to zone such that the alpha-decay dose is between 0.2 x 10(16) and 0.8 x 10(16) alpha-events per milligram (0.15 to 0.60 displacement per atom). The transition from the crystalline to the aperiodic metamict state occurs over this dose range. Differential expansion of individual layers due to variations in their alpha-decay dose caused a systematic pattern of fractures that do not propagate across aperiodic layers. High-resolution transmission electron microscopy revealed a systematic change in the microstructure from a periodic atomic array to an aperiodic array with increasing alpha-decay dose. At doses greater than 0.8 x 10(16) alpha-events per milligram there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides. PMID:17835739
Contingency of alpha decay in 287-306120 isotopes of SHE
In recent years the synthesis and identification of super heavy nuclei has a particular attention in the field of nuclear physics. Many theoretical calculations have been done to study the properties of even-Z Super heavy elements (SHE). Durate et al. applied the effective liquid drop model to predict the alpha decay, cluster emission and cold fission half-life values of nuclei on the region of super heavy elements, defined by 155 ≤ N ≤ 220 and 110 ≤ Z ≤ 135. In the case of super heavy elements spontaneous fission and alpha decay are the main decay modes. Super heavy nuclei which have relatively small alpha decay half times compared to spontaneous fission half lives will survive fission and thus can be detected in the laboratory through α-decay. The present paper aims to predict possibility of alpha decay in the element Z = 120 isotopes using CYE model and the spontaneous fission half lives are computed using the phenomenological formula
Role of nuclear surface tension coefficient in alpha decay process of the superheavy nuclei
The present paper role of nuclear surface tension in alpha decay resulted from the need to improve the Isospin Cluster Model, where the excess of neutron and proton numbers are taken in account effectively of a nucleus in decay calculations. The appropriate value of nuclear surface tension coefficient in proximity potential which plays an important role to estimate the nuclear attraction between two nuclear surfaces is reviewed, in this model. The nuclear proximity force is proportional to the surface tension and its contribution necessarily should be appropriate. The synthesis of super heavy elements, formed by either of cold fusion or hot fusion process, is primarily decay through alpha-particle emission. The successive emission of alpha particles from a superheavy element ends at spontaneous fission
Study of the excited levels of 233Pa by the 237Np alpha decay
The excited levels in 233Pa following the 237Np alpha decay have been studied, by performing different experiences to complete available data and supply new information. Thus, two direct alpha spectrum measurement, one alpha-gamma bidimensional coincidence experiment, three gamma-gamma and gamma-X ray coincidences and some other measurements of the gamma spectrum, direct and coincident with alpha-particles have been made. These last experiences have allowed to obviate usual radiochemical separation methods, the 233Pa radioactive descendent interferences being eliminated by means of the coincidence technic. As a result, a primary decay scheme has been elaborated, including 15 new gamma transitions and two new levels, not observed in the most recent works. (Author) 60 refs
On the Validity of the Geiger-Nuttall Alpha-Decay Law and its Microscopic Basis
Qi, C; Huyse, M; Liotta, R J; Van Duppen, P; Wyss, R
2014-01-01
The Geiger-Nuttall (GN) law relates the partial $\\alpha$-decay half-life with the energy of the escaping $\\alpha$ particle and contains for every isotopic chain two experimentally determined coefficients. The expression is supported by several phenomenological approaches, however its coefficients lack a fully microscopic basis. In this paper we will show that: 1) the empirical coefficients that appear in the GN law have a deep physical meaning and 2) the GN law is successful within the restricted experimental data sets available so far, but is not valid in general. We will show that, when the dependence of logarithm values of the $\\alpha$ formation probability on the neutron number is not linear or constant, the GN law is broken. For the $\\alpha$ decay of neutron-deficient nucleus $^{186}$Po, the difference between the experimental half-life and that predicted by the GN Law is as large as one order of magnitude.
Alpha-decay-induced fracturing in zircon - The transition from the crystalline to the metamict state
Chakoumakos, Bryan C.; Murakami, Takashi; Lumpkin, Gregory R.; Ewing, Rodney C.
1987-01-01
Zonation due to alpha-decay damage in a natural single crystal of zircon from Sri Lanka is discussed. The zones vary in thickness on a scale from one to hundreds of microns. The uranium and thorium concentrations vary from zone to zone such that the alpha decay dose is between 0.2 x 10 to the 16th and 0.8 x 10 to the 16th alpha-events per milligram. The transition from the crystalline to the aperiodic metamict state occurs over this dose range. At doses greater than 0.8 x 10 to the 16th alpha events/mg there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.
Alpha-decay-induced fracturing in zircon - The transition from the crystalline to the metamict state
Chakoumakos, Bryan C.; Murakami, Takashi; Lumpkin, Gregory R.; Ewing, Rodney C.
1987-06-01
Zonation due to alpha-decay damage in a natural single crystal of zircon from Sri Lanka is discussed. The zones vary in thickness on a scale from one to hundreds of microns. The uranium and thorium concentrations vary from zone to zone such that the alpha decay dose is between 0.2 x 10 to the 16th and 0.8 x 10 to the 16th alpha-events per milligram. The transition from the crystalline to the aperiodic metamict state occurs over this dose range. At doses greater than 0.8 x 10 to the 16th alpha events/mg there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.
Measurements of differential cross-sections of alpha-particle inelastic scattering by 7Li nuclei and 7Li(alpha, alpha 6Li)n, 7Li(alpha, alpha alpha)t reactions have been performed at the energy Ea = 27,2 MeV. Probability of 7Li*(7,45 MeV) decay into 6Li + n channel has been determined from the ratio of cross-sections measured in kinematically complete and incomplete experiments. The large discrepancy of this value (P 0,49 ± 0,06) and of those obtained at the study of 7Li*(7,45 MeV) decay in binary reactions can be explained by the influence of Coulomb field of accompanied alpha-particle on the decay of near-threshold resonances in three-particle reactions
Beta-alpha correlation in the decay of 20Na
The β-α angular correlation has been measured in the allowed positron decay of 20Na to the 7.42 MeV state of 20Ne. The correlation is of the form 1+a(mean)cos(theta) + p(mean)cos2(theta). p(mean)=-0.003+-0.005 is found in reasonable agreement with expectations based on the conserved vector current theory. (Auth.)
Improved Determination of the CKM Angle alpha from B to pi pi decays
Bóna, M; Franco, E; Lubicz, V; Martinelli, G; Parodi, F; Pierini, M; Roudeau, P; Schiavi, C; Silvestrini, L; Sordini, V; Stocchi, A; Vagnoni, V
2007-01-01
Motivated by a recent paper that compares the results of the analysis of the CKM angle alpha in the frequentist and in the Bayesian approaches, we have reconsidered the information on the hadronic amplitudes, which helps constraining the value of alpha in the Standard Model. We find that the Bayesian method gives consistent results irrespective of the parametrisation of the hadronic amplitudes and that the results of the frequentist and Bayesian approaches are equivalent when comparing meaningful probability ranges or confidence levels. We also find that from B to pi pi decays alone the 95% probability region for alpha is the interval [80^o,170^o], well consistent with recent analyses of the unitarity triangle where, by using all the available experimental and theoretical information, one gets alpha = (93 +- 4)^o. Last but not least, by using simple arguments on the hadronic matrix elements, we show that the unphysical region alpha ~ 0, present in several experimental analyses, can be eliminated.
Half-lives with Yukawa proximity potential for alpha-decay process
We intend to study the alpha-decay half-lives of some nuclei from ground state to ground state. We consider a potential model with Yukawa proximity potential. We see that the results are in good agreement with the experimental data. (author)
Alpha-Decay of $^{211}Po$ on the 1633 keV $^{207}Pb$ level
Chumin, V G; Malikov, Sh R; Norseev, Yu V; Samatov, Z K; Fominykh, V I; Cherevatenko, A P; Yurkova, L V
2000-01-01
In investigations of gamma-spectrum of ^{211}At and daughter ^{211}Po and ^{207}Bi isotopes a new branch of the alpha-decay on the ^{207}Pb 1633 keV level is discovered. Its intensity is 8.1 cdot 10^{-4} %.
Can a many-nucleon structure be visible in bremsstrahlung emission during $\\alpha$ decay?
Maydanyuk, Sergei P; Zou, Li-Ping
2015-01-01
We analyze if the nucleon structure of the $\\alpha$ decaying nucleus can be visible in the experimental bremsstrahlung spectra of the emitted photons which accompany such a decay. We develop a new formalism of the bremsstrahlung model taking into account distribution of nucleons in the $\\alpha$ decaying nuclear system. We conclude the following: (1) After inclusion of the nucleon structure into the model the calculated bremsstrahlung spectrum is changed very slowly for a majority of the $\\alpha$ decaying nuclei. However, we have observed that visible changes really exist for the $^{106}{\\rm Te}$ nucleus ($Q_{\\alpha}=4.29$ MeV, $T_{1/2}$=70 mks) even for the energy of the emitted photons up to 1 MeV. This nucleus is a good candidate for future experimental study of this task. (2) Inclusion of the nucleon structure into the model increases the bremsstrahlung probability of the emitted photons. (3) We find the following tendencies for obtaining the nuclei, which have bremsstrahlung spectra more sensitive to the ...
The Resonance Theory of Proton and Alpha Decay from Hot Sources
Karpeshin, F F; Vardaci, E; Brondi, A; Moro, R; Abramovich, S N; Serov, V I; Vardaci, Emanuele; Brondi, Augusto; Moro, Renata
2005-01-01
The consecutive microscopic solution is presented of the problem of tunneling of a particle through a potential barrier. The method is applied to the alpha and proton decay of compound systems formed in fusion reaction. Appearance of the peaks in the spectrum of emitted particles is predicted. The peaks correspond to quasistationary states inside the potential barrier.
Plutonium-238 alpha-decay damage study of the ceramic waste form.
Frank, S M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Barber, T L [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Cummings, D G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; DiSanto, T [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Esh, D W [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; Giglio, J J [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Goff, K M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Johnson, S G [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Kennedy, J R [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Jue, J-F [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Noy, M [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; O' Holleran, T P [U.S. Department of Energy, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415; Sinkler, W [UOP LLC, 25 E Algonquin Road, Des Plaines, IL 60017
2006-03-27
An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with {sup 238}Pu which has a much greater specific activity than {sup 239}Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10{sup 18} alpha-decays/gram of material. An equivalent time period for a similar dose of {sup 239}Pu would require approximately 1100 years. After four years of exposure to {sup 238}Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the {sup 238}Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) {sup 238}Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell
The measurement of CKM-angle $alpha$ using decays of $B^0_d \\ r ightarrow pi^+ pi^- pi^0$
Jacholkowska, A
2000-01-01
The preliminary study of the decay Bo->3pi to extract the CKM--angle alpha is presented. The theoretical background to the extraction of alpha using the decay Bo->3pi and its advantages over using the decay Bo->2pi are outlined. Studies of the selection of the decays Bo->3pi will be presented. In particular, the use of a discriminant variable to suppress background w ill be described. In addition,studies of the extraction of alpha are presented and the possible sensitivity after 1 and 5 years of LHC running are given.
Bremsstrahlung emission probability in the {alpha} decay of {sup 210}Po
Boie, Hans-Hermann
2009-06-03
A high-statistics measurement of bremsstrahlung emitted in the {alpha} decay of {sup 210}Po has been performed. The measured differential emission probabilities, which could be followed up to {gamma}-energies of {proportional_to} 500 keV, allow for the first time for a serious test of various model calculations of the bremsstrahlung accompanied {alpha} decay. It is shown that corrections to the {alpha}-{gamma} angular correlation due to the interference between the electric dipole and quadrupole amplitudes and due to the relativistic character of the process have to be taken into account. With the experimentally derived angular correlation the measured energydifferential bremsstrahlung emission probabilities show excellent agreement with the fully quantum mechanical calculation. (orig.)
The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault. (author)
Zhang, Linfeng
2015-01-01
The $\\alpha$-decay energies ($Q_\\alpha$) are systematically investigated with the nuclear masses for $10 \\leq Z \\leq 120$ isotopes obtained by the relativistic continuum Hartree-Bogoliubov (RCHB) theory with the covariant density functional PC-PK1, and compared with available experimental values. It is found that the $\\alpha$-decay energies deduced from the RCHB results present similar pattern as those from available experiments. Owing to the large predicted $Q_\\alpha$ values ($\\geq$ 4 MeV), many undiscovered heavy nuclei in the proton-rich side and super-heavy nuclei may have large possibilities for $\\alpha$-decay. The influence of nuclear shell structure on $\\alpha$-decay energies is also analysed.
Alpha-decay damage of Cm-doped perovskite
Curium-doped perovskite slurry, which had the nominal composition of Ca0.98919(CM,Pu)0.01081Al0.01081Ti0.98919O3, was calcined at 750 C for 2 h and then hot-pressed at 1,250 C and 29MPa for 2 h. The hot-pressed cylinder samples had the specific 244Cm activity of 22.3 GBq/g on 31 March 1993. Their average density was 4.083 g/cm3 after the samples got a cumulative dose of 0.7 x 1017 α decays/g. The rate of density change was slightly larger in the present perovskite material than in Cm-doped Synroc reported previously. Half-disk perovskite specimens, which had accumulated doses of 1.6 x 1017 and 4.0 x 1017 α decays/g, were MCC-1 leach tested in pH ∼2 solution at 90 C and 2.3 g/m2/day, respectively. These high leach rates caused a significant increase in pH in the later stage of the leaching runs. As-leached surfaces of Cm-doped perovskite showed the formation of anatase (TiO2). For the first 28 days, the Ca and Cm leach rates at the two different doses increased with leach time. More damaged specimens tended to give higher leach rates. In the final 28-day leaching run, both leach rates at the two different doses converged on each lower value although the Cm leach rate was lower than the Ca leach rate by a factor of >20. Nonradioactive perovskite material showed similar changes in Ca leach rate and pH to the Cm-doped one although the as-leached surfaces of the former material showed much higher degree of alteration of perovskite to anatase
Angular correlation measurements for 4-{alpha} decaying states in {sup 16}O
Wuosmaa, A.H.; Back, B.B.; Betts, R.R. [and others
1995-08-01
Previous measurements of the {sup 12}C({sup 12}C,{sup 8}Be){sup 16}O{sup *}(4 {alpha}) reaction identified discrete levels in {sup 16}O which decay by breakup into 4 {alpha} particles through a number of different decay sequences, including {sup 16}O{sup *} {yields} {sup 8}Be + {sup 8}Be and {alpha} + {sup 12}C (O{sub 2}{sup +}). These states are observed in a range of excitation energies where resonances are observed in inelastic {alpha} + {sup 12}C scattering leading to the {sup 8}Be + {sup 8}Be and {alpha} + {sup 12}C final states. These resonances were associated with 4 {alpha}-particle chain configurations in {sup 16}O. Should the states populated in the {sup 12}C + {sup 12}C reaction possess this same extended structure, it would serve as an important piece of evidence supporting the idea that even more deformed structures are formed in the {sup 24}Mg compound system. In order to more firmly make this association, it is important to determine the spins of the states populated in the {sup 12}C + {sup 12}C reaction.
Effects of alpha-decay on spent fuel corrosion behaviour
An overview of results in the area of spent fuel characterization as nuclear waste is presented. These studies are focused on primary aspects of spent fuel corrosion, by considering different fuel compositions and burn ups, as well as a wide set of environmental conditions. The key parameter is the storage time of the fuel e.g. in view of spent fuel retrieval or in view of its final disposal. To extrapolate data obtainable from a laboratory-acceptable timescale to those expected after storage periods of interest have elapsed (amounting in the extreme case to geological ages) is a tough challenge. Emphasis is put on key aspects of fuel corrosion related to fuel properties at a given age and environmental conditions expected in the repository: e.g. the fuel activity (radiolysis effects), the effects of helium build-up and of groundwater composition. A wide range of techniques, from traditional leaching experiments to advanced electrochemistry, and of materials, including spent fuel with different compositions/burnups and analogues like the so-called alpha-doped UO2, are employed for these studies. The results confirm the safety of European underground repository concepts. (authors)
Phenomenological formula for alpha-decay half-lives
A phenomenological formula is presented for the partial half-life from the Q value for α decay. It is constructed in a conventional way by considering the penetrability of a charged particle in a spherical Coulomb potential. Parameters in the formula are fixed because they are determined by physical constants except for the following three adjustable parameters: the product of the collision frequency of an α particle and the formation probability, N; the distance between the charge radius and the radius of an inner point of the Coulomb barrier, r 0; and the odd-mass hindrance, h 0. The values obtained for the three adjustable parameters are reasonable, in contrast with those of conventional models such as the Viola-Seaborg formula. The root-mean-square deviations from experimental partial half-lives for even-even, odd-A, and odd-odd nuclei are 0.344, 0.740, and 0.940 (in log10), respectively. The obtained formula gives half-lives that are two or three times longer than those obtained using the Viola-Seaborg formula in the superheavy nuclear mass region. (author)
Measurement of the branching ratio for beta-delayed alpha decay of 16N
Refsgaard, J; Dijck, E A; Fynbo, H O U; Lund, M V; Portela, M N; Raabe, R; Randisi, G; Renzi, F; Sambi, S; Sytema, A; Willmann, L; Wilschut, H W
2015-01-01
While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 25% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor.
Evidence for B0->rho0rho0 Decay and Implications for the CKM Angle alpha
Aubert, B; Abrams, G S; Adye, T; Ahmed, S; Alam, M S; Albert, J; Aleksan, R; Allen, M T; Allison, J; Altenburg, D D; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Asgeirsson, D J; Aston, D; Azzolini, V; Baak, M A; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, Sw; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Bechtle, P; Beck, T W; Behera, P K; Bellini, F; Ben-Haim, E; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Bettarini, S; Bettoni, D; Bevan, A J; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, V E; Bloom, P C; Blount, N L; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Boyd, J T; Bozzi, C; Brandt, T; Brau, J E; Briand, H; Brown, D N; Bruinsma, M; Brunet, S; Buchanan, C; Bugg, W; Bukin, A D; Bula, R; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Carpinelli, M; Cartaro, C; Castelli, G; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Chen, X R; Cheng, C H; Chia, Y M; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Corwin, L A; Cossutti, F; Cottingham, W N; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cunha, A; Curry, S; Côté, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Dasu, S; Dauncey, P D; David, P; Davier, M; Davis, C L; De Nardo, Gallieno; De Sangro, R; Del Amo-Sánchez, P; Del Buono, L; Del Re, D; Della Ricca, G; Denig, A G; Di Lodovico, F; Di Marco, E; Dingfelder, J C; Dong, L; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Dvoretskii, A; Ebert, M; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Escalier, M; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fang, F; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, W T; Forster, I J; Forti, F; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; Gaz, A; George, K A; Giorgi, M A; Gladney, L; Glanzman, T; Godang, R; Golubev, V B; Gowdy, S J; Gradl, W; Graham, M T; Graugès-Pous, E; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jain, V; Jasper, H; Jawahery, A; Jessop, C P; Kadyk, J A; Kagan, H; Karyotakis, Yu; Kass, R; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Klose, V; Knecht, N S; Koch, H; Kolb, J A; Kolomensky, Yu G; Kovalskyi, D; Kowalewski, R V; Kozanecki, W; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Lankford, A J; Latham, T E; Latour, E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, S; Li, X; Lista, L; Liu, F; Liu, H; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; Long, O; Lopes-Pegna, D; Lopez-March, N; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martin, E C; Martínez-Vidal, F; Mattison, T S; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Mclachlin, S E; Meadows, B T; Mellado, B; Menges, W; Merkel, J; Messner, R; Meyer, N T; Meyer, W T; Mir, L M; Mishra, K; Mohanty, G B; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morganti, M; Morganti, S; Morii, M; Morris, J P; Muheim, F; Müller, D R; Nagel, M; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nicholson, H; Nikolich, M B; Nogowski, R; Nugent, I M; O'Grady, C P; Ocariz, J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Osipenkov, I; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, B; Pan, Y; Panduro-Vazquez, W; Paoloni, E; Paolucci, P; Pappagallo, M; Park, W; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Pelliccioni, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petrella, A; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Piredda, G; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prencipe, E; Prepost, R; Pripstein, M; Prudent, X; Pruvot, S; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rahmat, R; Rama, M; Ratcliff, B N; Raven, G; Regensburger, J J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roberts, D A; Robertson, A I; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Röthel, W; Sacco, R; Saeed, M A; Saleem, M; Salnikov, A A; Salvati, E; Salvatore, F; Sanders, D A; Santroni, A; Saremi, S; Schalk, T; Schenk, S; Schilling, C J; Schindler, R H; Schofield, K C; Schott, G; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Serrano, J; Sharma, V; Shen, B C; Sherwood, D J; Simard, M; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Tackmann, K; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Thiebaux, C; Thompson, J M; Tisserand, V; Todyshev, K Yu; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasseur, G; Vavra, J; Verderi, M; Viaud, F B; Vitale, L; Voci, C; Voena, C; Volk, A; Wacker, K; Wagner, A P; Wagner, S R; Waldi, R; Walker, D; Walsh, J J; Wang, P; Wang, W F; Wappler, F R; Watson, A T; Weaver, M; Wenzel, W A; West, T J; Wilden, L; Williams, D C; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Winklmeier, F; Winstrom, L O; Wisniewski, W J; Wittgen, M; Wong, Q K; Wormser, G; Wren, A C; Wright, D H; Wright, D M; Wu, J; Wu, S L; Wulsin, H W; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J I; Yi, K; Young, C C; Yu, Z; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T; al, et
2006-01-01
We search for the decays B0->rho0rho0, B0->rho0f0, and B0->f0f0 in a sample of about 384 million Upsilon(4S)->BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find evidence for B0->rho0rho0 with 3.5 sigma significance and measure the branching fraction BR = (1.07+-0.33+-0.19)10^-6 and longitudinal polarization fraction f_L = 0.87+-0.13+-0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the CKM unitarity angle alpha due to penguin contributions in B-> rho rho decays is 18 degrees at the 1 sigma level. We also set upper limits on the B0->rho0f0 and B0->f0f0 decay rates.
Single universal curve for Alpha decay derived from semi-microscopic calculations
Ismail, M; Ellithi, A Y; Abdurrahman, A
2015-01-01
The universal curve is one of the simple ways to get preliminary information about the Alpha-decay half-life times of heavy nuclei. We try to find parameterization for the universal curve of Alpha decay based on semi-microscopic calculations, starting from the realistic M3Y-Reid nucleon-nucleon interaction. Within the deformed density-dependent cluster model, the penetration probability and the assault frequency are calculated using the WKB penetration probability. The deformations of daughter nuclei and the ground-state spin and parity of the involved nuclei are considered. We found that it is accurate enough to express the assault frequency, for all studied decays, either as a function of the mass number of the parent nuclei or as a constant average value. The average preformation probability of the Alpha cluster inside four groups of 166 even(Z)-even(N), 117 odd-even, 141 even-odd, and 72 odd-odd Alpha-emitters are obtained, individually. The effect of participating unpaired nucleons in the involved nuclei...
Highly anisotropic decay rate of single quantum dots in photonic crystal membranes
Wang, Qin; Stobbe, Søren; Nielsen, Henri Thyrrestrup; Hofmann, Holger; Kamp, Martin; Friess, Benedikt; Worschech, Lukas; Schlereth, Thomas; Hofling, Sven; Lodahl, Peter
We measured the variation of spontaneous emission rates with polarization for self-assembled single quantum-dots in photonic crystal membranes, and obtained a maximum anisotropy factor of 6 between decay rates of the two nondegenerate bright states....
ALPHA - The long-term passive decay heat removal and aerosol retention program
The Paul Scherrer Institute initiated the major new experimental and analytical program ALPHA in 1990. The program is aimed at understanding the long-term decay heat removal and aerosol questions for the next generation of Passive Light Water Reactors. The ALPHA project currently includes four major items: the large-scale, integral system behaviour test facility PANDA, which will be used to examine multidimensional effects of the SBWR decay heat removal system; an investigation of the thermal hydraulics of natural convection and mixing in pools and large volumes (LINX); a separate-effects study of aerosols transport and deposition in plenum and tubes (AIDA); while finally, data from the PANDA facility and supporting separate effects tests will be used to develop and qualify models and provide validation of relevant system codes. The paper briefly reviews the above four topics and current status of the experimental facilities. (author). 3 refs, 12 figs
O(N{sub f}{alpha}{sup 2}) corrections to muon decay
Stuart, R.G. [Randall Laboratory pf Physics, Ann Arbor, Michigan (United States)
1997-03-01
The calculation of the O(N{sub f}{alpha}{sup 2}) corrections to muon decay is described. These are the 2-loop diagrams containing a massless fermion loop and they form an important gauge-invariant subclass. It is shown that all such diagrams can be expressed in terms of universal master integral. We focus on the calculation of box diagrams and in particular on the removal of the ir infrared divergences. (author) 14 refs, 2 figs
Alpha-decay energies of superheavy nuclei for the Fayans functional
Tolokonnikov, S V; Kortelainen, M; Lutostansky, Yu S; Saperstein, E E
2016-01-01
Alpha-decay energies for several chains of super-heavy nuclei are calculated by using Fayans functional FaNDF$^0$. They are compared to the experimental data and predictions of two Skyrme functionals, SLy4 and SkM*, and of the macro-micro method as well. The corresponding lifetimes are calculated with the use of the semi-phenomenological formulas by Parkhomenko and Sobiczewski and by Royer and Zhang.
O(alpha_s^2) corrections to fermionic Higgs decays in the MSSM
Mihaila, L
2010-01-01
We compute the two-loop corrections of O(alpha_s^2) to the Yukawa couplings in the framework of the Minimal Supersymmetric Standard Model (MSSM). The calculation is performed using the effective Lagrangian approach under the approximation of neglecting the Higgs boson mass with respect to the top quark, gluino and all squark flavour masses. As an application we derive the O(alpha_s^2) corrections to the partial decay width of the lightest Higgs boson to a bottom quark pair. We find that the two-loop corrections are sizable for large values of tan_beta and low CP-odd Higgs boson mass. With our calculation of the O(alpha_s^2) corrections the remaining theoretical uncertainties reduce below a few percent.
Updated determination of $\\alpha_s(m_\\tau^2)$ from tau decays
Pich, Antonio
2016-01-01
Using the most recent release of the ALEPH $\\tau$ decay data, we present a very detailed phenomenological update of the $\\alpha_s(m_\\tau^2)$ determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find $\\alpha_{s}^{(n_f=3)}(m_\\tau^2) = 0.328 \\pm 0.012$ which implies $\\alpha_{s}^{(n_f=5)}(M_Z^{2}) = 0.1197\\pm 0.0014$. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values.
Pairing gaps and Fermi energies at scission for 296Lv alpha-decay
Mirea, M
2014-01-01
The pairing corrections, the single particle occupation numbers, are investigated within density-dependent delta interaction formalism for pairing residual interactions. The potential barrier is computed in the framework of the macroscopic-microscopic model. The microscopic part is based on the Woods-Saxon two center shell model. The alpha-decay of a superheavy element is treated, by paying a special attention to the region of the scission configurations. The sequence of nuclear shapes follows the superasymmetric fission path for alpha decay. It was found that the pairing gaps of the states that reach asymptotically the potential well of the alpha particle have large values at scission but become zero after scission. The 1s1/2 single particle levels of the nascent alpha particle are fully occupied while the superior levels are empties in the scission region and remains in the same states during the penetration of the Coulomb barrier. The projection of the numbers of particle on the two fragments are obtained ...
Unified description of the proton, alpha, cluster decays and spontaneously fissions half- life
Mavrodiev, Strachimir Cht
2016-01-01
Some time ago the possibility of classical (without Gamow tunneling) universal description of radioactive nuclei decay was demonstrated. Such possibility is basis on the classical interpretation of Bohmian Psi-field reality in Bohmian-Chetaev mechanics and the hypothesis for the presence of dissipative forces, generated from the Gryzinski translational precession of the charged particles spin, in Langevin- Kramers diffusion mechanism. In this paper is present an unified model of proton, alpha decay, cluster radioactivity and spontaneous fission half-life as explicit function which depends on the total decay energy and kinetic energy, the number of protons and neutrons of daughter product, the number of protons and neutrons of mother nuclei and from a set) unknown digital parameters. The Half- lifes of the 573 nuclei taken from NuDat database together with the recent experimental data from Oganessian provide a basis for discovering the explicit form of the Kramers solution of Langevin type equation in a framew...
2007-01-01
It has recently been suggested, and indicated experimentally, that $\\alpha$- decay half-lives are modified by solid state effects in the surrounding environment. We propose here to measure with high accuracy the $\\alpha$-decay half-life of $^{221}$Fr, $^{224}$Ra and $^{226}$Ra in insulators and metals. Furthermore we plan to investigate the temperature dependency of the half-life in these materials (room temperature, 4 K and 10 mK).
Wang, Qin; Stobbe, Søren; Nielsen, Henri Thyrrestrup; Hofmann, Holger; Kamp, Martin; Schlereth, thomas; Höfling, Sven; Lodahl, Peter
We have systematically measured the variation of the spontaneous emission rate with polarization for self-assembled single quantum dots in two-dimensional photonic crystal membranes and obtained a maximum anisotropy factor of 6 between the decay rates of the two nondegenerate bright exciton states....
Highly anisotropic decay rates of single quantum dots in photonic crystal membranes
Wang, Qin; Stobbe, Søren; Nielsen, Henri Thyrrestrup; Hofmann, H.; Kamp, M.; Schlereth, T.W.; Höfling, S.; Lodahl, Peter
We have measured the variation of the spontaneous emission rate with polarization for self-assembled single quantum dots in two-dimensional photonic crystal membranes. We observe a maximum anisotropy factor of 6 between the decay rates of the two bright exciton states. This large anisotropy is at...
Araújo, Vitor; Melbourne, Ian
2015-01-01
We prove exponential decay of correlations for a class of $C^{1+\\alpha}$ uniformly hyperbolic skew product flows, subject to a uniform nonintegrability condition. In particular, this establishes exponential decay of correlations for an open set of geometric Lorenz attractors. As a special case, we show that the classical Lorenz attractor is robustly exponentially mixing.
Shape coexistence and shell-model intruder states in the lead region studied by $\\alpha$ -decay
2002-01-01
% IS336 \\\\ \\\\ Low-lying 0$^+$ states in even-even nuclei near closed shells can be a manifestation of the coexistence of different shapes in the same nucleus. Deformed bandstructures built upon these 0$^+$ states, coexisting at low energy with the ground state band, have been observed in several regions of the nuclear chart, including the Z=82 region. Such structures have been found in the neutron-deficient even Pb nuclei and the mixing between intruder and normal states has been studied by the $\\alpha$- decay of $^{194, 196, 198}$Po towards the 0$^+$ excited and ground states in $^{190, 192, 194}$Pb using $\\alpha$-e-t coincidence events. It is expected that shape coexistence will occur in the light Po isotopes as well. Evidence for a deformed band at low excitation energy in $^{196, 198}$Po has been found in in-beam studies and the $\\alpha$-decay of $^{202}$Rn studied at ISOLDE revealed feeding to a 0$^+$~state at 816~keV in $^{198}$Po. \\\\ \\\\It is our intention to investigate the $^{194, 196}$Po nuclei with ...
Revisiting alpha decay-based near-light-speed particle propulsion.
Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu
2016-08-01
Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days. PMID:27161512
Differential cross-sections of excitation and decay of 7Li*(7,45 MeV) resonance into 6Li + n channel in three particle reaction 7Li(alpha, alpha6Li)n at alpha-particle energy of 27,2 MeV have been determined in kinematically complete and incomplete experiments. Usage of position sensitive detector made it possible to obtain the data on space distributions of decay events for full range of possible angles and to determine the total probability of this process, which value essentially differs from the data for binary reactions. This result is agreed with previously obtained [1] and confirms the theoretical calculations [2] of decay branching ratio for short lived near-threshold resonances in three particle reactions
Extended systematics of alpha decay half lives for exotic superheavy nuclei
Budaca, A I; Silisteanu, I
2016-01-01
The experimentally available data on the alpha decay half lives and Q? values for 96 superheavy nuclei are used to fix the parameters for a modified version of the Brown empirical formula through two fitting procedures which enables its comparison with similar fits using Viola-Seaborg and Royer formulas. The new expressions provide very good agreement with experimental data having fewer or the same number of parameters. All formulas with the obtained parameters are then extrapolated to generate half lives predictions for 125 unknown superheavy alpha emitters. The nuclei where the employed empirical formulas maximally or minimally diverge are pointed out and a selection of 36 nuclei with exceptional superposition of predictions was made for experimental reference.
A brief review of ultra-rare alpha decay detection technique
Three approaches to the measurement of rare alpha decaying products produced in heavy-ion induced nuclear reactions are described. One is based on a chemical extraction and following deposition of the nuclides under investigation onto the surface of the detector, whereas the second one is associated with long-lived products implanted into silicon detectors by using the electromagnetic separation technique. The third approach relates with an application of real-time mode detection of correlated energy-time-position recoil-alpha sequences from 48Ca-induced nuclear reactions with actinide targets, like 242,244Pu, 245,248Cm, 243Am, and 249Cf. Namely with this technique it has became possible to provide a radical suppression of backgrounds in the full fusion (3-5n) reactions aimed at the synthesis of superheavy elements with Z = 113-118
A Brief Review of Ultra-Rare Alpha Decay Detection Technique
Tsyganov, Yu S
2006-01-01
Three approaches to the measurement of a rare alpha decaying products produced in heavy-ion induced nuclear reactions are described. One is based on a chemical extraction and following deposition of the nuclides under investigation onto the surface of the detector, whereas the second one is associated with long-lived products implanted into silicon detectors by using the electromagnetic separation technique. The third approach relates with an application of real-time mode detection of correlated energy-time-position recoil-alpha sequences from $^{48}$Ca-induced nuclear reactions with actinide targets, like $^{242, 244}$Pu, $^{245,248}$Cm, $^{243}$Am, and $^{249}$Cf. Namely with this technique it has became possible to provide a radical suppression of backgrounds in the full fusion (3-5$n$) reactions aimed at the synthesis of superheavy elements with Z=113-118.
GAMCAT - a personal computer database on alpha particles and gamma rays from radioactive decay
The GAMCAT database is a compilation of data describing the alpha particles and gamma rays that occur in the radioactive decay of all known nuclides, adapted for IBM Personal Computers and compatible systems. These compiled data have been previously published, and are now available as a compact database. Entries can be retrieved by defining the properties of the parent nuclei as well as alpha-particle and gamma-ray energies or any combination of these parameters. The system provides fast access to the data and has been completely written in C to run on an AT-compatible computer, with a hard disk and 640K of memory under DOS 2.11 or higher. GAMCAT is available from the Fachinformationszentrum Karlsruhe. (orig.)
Issues in Determining {alpha}{sub s} from Hadronic {tau} Decay and Electroproduction Data
Boito, D. [Departament de Fisica and IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Cata, O. [Departament de Fisica Teorica and IFIC Universitat de Valencia-CSIC, E-46071 Valencia (Spain); Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Arnold Sommerfeld Center for Theoretical Physics, D80333 Muenchen (Germany); Golterman, M. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Jamin, M. [ICREA, IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain); Maltman, K. [Dept. Math and Statistics, York University, Toronto, ON Canada M3J 1P3 (Canada); CSSM, University of Adelaide, Adelaide, SA Australia 5005 (Australia); Osborne, J. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Peris, S. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)
2012-04-15
We discuss some key issues associated with duality-violating and non-perturbative OPE contributions to the theoretical representations of light quark current-current two-point functions and relevant to precision determinations of {alpha}{sub s} from hadronic {tau} decay and electroproduction cross-section data. We demonstrate that analyses with an explicit representation of duality-violating effects are required to bring theoretical errors in such extractions under control, motivating the accompanying paper in these proceedings, which presents the results of such an analysis.
Simulation of alpha decay of actinides in iron phosphate glasses by ion irradiation
Dube, Charu L.; Stennett, Martin C.; Gandy, Amy S.; Hyatt, Neil C.
2016-03-01
A surrogate approach of ion beam irradiation is employed to simulate alpha decay of actinides in iron phosphate nuclear waste glasses. Bismuth and helium ions of different energies have been selected for simulating glass matrix modification owing to radiolysis and ballistic damage due to recoil atoms. Structural modification and change in coordination number of network former were probed by employing Reflectance Fourier-Transform Infrared (FT-IR), and Raman spectroscopies as a consequence of ion irradiation. Depolymerisation is observed in glass sample irradiated at intermediate energy of 2 MeV. Helium blisters of micron size are seen in glass sample irradiated at low helium ion energy of 30 keV.
In the framework of Bohmian quantum mechanics supplemented with the Chetaev theorem on stable trajectories in dynamics in the presence of dissipative forces we have shown the possibility of the classical (without tunneling) universal description of radioactive decay of heavy nuclei, in which under certain conditions the so-called noise-induced transition is generated or, in other words, the stochastic channel of alpha decay, cluster radioactivity and spontaneous fission conditioned by the Kramers diffusion mechanism. Based on the ENSDF database we have found the parametrized solutions of the Kramers equation of Langevin type by Alexandrov dynamic auto--regularization method (FORTRAN code REGN-Dubna). These solutions describe with high accuracy the dependence of the half-life (decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products. The verification of inverse problem solution in the framework of the universal Kramers description of the alpha decay, cluster radioactivity and spontaneous fission, which was based on the newest experimental data for alpha decay of even-even superheavy nuclei (Z = 114, 116, 118), has shown good coincidence of the experimental and theoretical half-life dependence on alpha-decay energy
Anisotropic strain in {alpha}-plane GaN and polarization dependence of the Raman peaks
Katsikini, M.; Ves, S.; Dimitrakopulos, G.P. [School of Physics, Aristotle University of Thessaloniki (Greece); Arvanitidis, J. [School of Physics, Aristotle University of Thessaloniki (Greece); Department of Applied Sciences, Technological Educational Institute of Thessaloniki, Sindos (Greece); Christofilos, D. [Physics Division, School of Technology, Aristotle University of Thessaloniki (Greece); Tsiakatouras, G.; Tsagaraki, K.; Georgakilas, A. [Department of Physics, Microelectronics Research Group, University of Crete, Heraklion (Greece); IESL, FORTH, Heraklion (Greece)
2012-06-15
The strain anisotropy of a-plane GaN epilayers is studied by polarization-dependent Raman spectroscopy. The intensity dependence of the A{sub 1}(TO), E{sub 1}(TO) and E{sub 2}{sup 2} Raman peaks for an almost strain-free epilayer is well explained by using Raman tensors of C{sub 6v} symmetry. However, the corresponding angular dependence for anisotropically strained GaN with vertical stroke {epsilon}{sub xx} - {epsilon}{sub yy} vertical stroke {proportional_to}6 x 10{sup -3} (where x parallel a and y parallel m axes) dictates the use of a perturbation term of C{sub 2v} symmetry that accounts for the orthorhombic distortion of the hexagonal unit cell. The consideration of this term elucidates the appearance of the E{sub 2}{sup 2} mode for such epilayer orientations where it is forbidden by the hexagonal symmetry. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Karpeshin, F. F., E-mail: fkarpeshin@gmail.com [D.I. Mendeleev Institute for Metrology (VNIIM) (Russian Federation); Trzhaskovskaya, M. B. [National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)
2015-12-15
Special features of the effect of the electron shell on alpha decay that have important experimental implications are studied within the adiabatic approach. The magnitude of the effect is about several tenths of a percent or smaller, depending on the transition energy and on the atomic number. A dominant role of inner shells is shown: more than 80% of the effect is saturated by 1s electrons. This circumstance plays a crucial role for experiments, making it possible to measure this small effect by a difference method in the same storage rings via a comparison of, for example, decay probabilities in bare nuclei and heliumlike ions. The reasons behind the relative success and the applicability limits of the frozen-shell model, which has been used to calculate the effect in question for more than half a century, are analyzed. An interesting experiment aimed at studying charged alpha-particle states is proposed. This experiment will furnish unique information for testing our ideas of the interplay of nonadiabatic and adiabatic processes.
Special features of the effect of the electron shell on alpha decay that have important experimental implications are studied within the adiabatic approach. The magnitude of the effect is about several tenths of a percent or smaller, depending on the transition energy and on the atomic number. A dominant role of inner shells is shown: more than 80% of the effect is saturated by 1s electrons. This circumstance plays a crucial role for experiments, making it possible to measure this small effect by a difference method in the same storage rings via a comparison of, for example, decay probabilities in bare nuclei and heliumlike ions. The reasons behind the relative success and the applicability limits of the frozen-shell model, which has been used to calculate the effect in question for more than half a century, are analyzed. An interesting experiment aimed at studying charged alpha-particle states is proposed. This experiment will furnish unique information for testing our ideas of the interplay of nonadiabatic and adiabatic processes
Studies on alpha-decay damage of high actinide-doped glasses in Japan
Accelerated experiments using the actinide doping technique were performed to investigate the effects of alpha-decay on the properties of nuclear waste glasses at high radiation doses. (1) The microstructural changes of a simulated waste glass irradiated with doping of 238PuO2 (0.96 wt%) and 244CmO2 (1.64 wt%) were observed by use of a pre-shadowed carbon replica technique in combination with scanning electron microscopy (SEM). In the glass irradiated at a dose of 1 x 1019 α-decays/g, bubbles with a radius from 0.15μm to 0.35μm were observed. The average bubble radius and its density were 0.23μm and 1 x 1017 bubbles/m3, respectively. The observation of bubbles in the glass annealed after irradiation indicated that the average radius decreased with annealing time. The bubble radius as a function of annealing time was calculated on the basis of the helium diffusion model with two chemical processes, i.e. trapping at bubbles and re-solution from bubbles into glass matrix. The calculated curve was in good agreement with the observed data. (2) A fully radioactive borosilicate waste glass, containing the actual high-level radioactive liquid waste generated from the Tokai Reprocessing Plant of Power Reactor and Nuclear Fuel Development Corporation (PNC), was prepared by Japan Atomic Energy Research Institute (JAERI), and a powder mixture of the ground fully radioactive glass and 244CmO2 (1.0 x 1010 Bq/g-glass, 0.4 wt%) was melted at 1200 deg C for 2 hours. The homogeneity of curium-doped glass samples was confirmed by the density measurement, heat load measurement and alpha autoradiography. The properties of the irradiated samples were investigated by the mass spectrometer for helium determination, the optical microscope, the electron probe micro-analyzer, the densitometer, the Soxhlet and MCC-1 leach testing apparatus. By measuring the amount of helium released from the samples, more than 99% of helium remained in the matrix at room temperature. The density of the
Deschanels, X.; Seydoux-Guillaume, A. M.; Magnin, V.; Mesbah, A.; Tribet, M.; Moloney, M. P.; Serruys, Y.; Peuget, S.
2014-05-01
Zirconolite and monazite matrices are potential ceramics for the containment of actinides (Np, Cm, Am, Pu) which are produced over the reprocessing of spent nuclear fuel. Actinides decay mainly through the emission of alpha particles, which in turn causes most ceramics to undergo structural and textural changes (amorphization and/or swelling). In order to study the effects of alpha decays on the above mentioned ceramics two parallel approaches were set up. The first involved the use of an external irradiation source, Au, which allowed the deposited recoil energy to be simulated. The second was based on short-lived actinide doping with 238Pu, (i.e. an internal source), via the incorporation of plutonium oxide into both the monazite and zirconolite structures during synthesis. In both types of irradiation experiments, the zirconolite samples became amorphous at room temperature with damage close to 0.3 dpa; corresponding to a critical dose of 4 × 1018 α g-1 (i.e. ∼1.3 × 1021 keV cm-3). Both zirconolite samples also showed the same degree of macroscopic swelling at saturation (∼6%), with ballistic processes being the predominant damaging effect. In the case of the monazite however, the macroscopic swelling and amorphization were dependent on the nature of the irradiation. Externally, (Au), irradiated samples became amorphous while also demonstrating a saturation swelling of up to 8%. In contrast to this, the swelling of the 238Pu doped samples was much smaller at ∼1%. Also, unlike the externally (Au) irradiated monazite these 238Pu doped samples remained crystalline up to 7.5 × 1018 α g-1 (0.8 dpa). XRD, TEM and swelling measurements were used to fully characterize and interpret this behavior. The low swelling and the conservation of the crystalline state of 238Pu doped monazite samples indicates that alpha annealing took place within this material.
Albert, J B; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; O'Sullivan, K; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Robinson, A; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wright, J D; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya
2015-01-01
Alpha decays in the EXO-200 detector are used to measure the fraction of charged $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Bi}$ daughters created from alpha and beta decays, respectively. $^{222}\\mathrm{Rn}$ alpha decays in liquid xenon (LXe) are found to produce $^{218}\\mathrm{Po}^{+}$ ions $50.3 \\pm 3.0\\%$ of the time, while the remainder of the $^{218}\\mathrm{Po}$ atoms are neutral. The fraction of $^{214}\\mathrm{Bi}^{+}$ from $^{214}\\mathrm{Pb}$ beta decays in LXe is found to be $76.4 \\pm 5.7\\%$, inferred from the relative rates of $^{218}\\mathrm{Po}$ and $^{214}\\mathrm{Po}$ alpha decays in the LXe. The average velocity of $^{218}\\mathrm{Po}$ ions is observed to decrease for longer drift times. Initially the ions have a mobility of $0.390 \\pm 0.006~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$, and at long drift times the mobility is $0.219 \\pm 0.004~\\mathrm{cm}^2/(\\mathrm{kV}~\\mathrm{s})$. Time constants associated with the change in mobility during drift of the $^{218}\\mathrm{Po}^{+}$ ions are found to be propor...
Hibbs, Ryan E; Johnson, David A; Shi, Jianxin; Hansen, Scott B; Taylor, Palmer
2005-12-20
The three-fingered alpha-neurotoxins have played a pivotal role in elucidating the structure and function of the muscle-type and neuronal alpha7 nicotinic acetylcholine receptors (nAChRs). To advance our understanding of the alpha-neurotoxin-nAChR interaction, we examined the flexibility of alpha-neurotoxin bound to the acetylcholine-binding protein (AChBP), which shares structural similarity and sequence identities with the extracellular domain of nAChRs. Because the crystal structure of five alpha-cobratoxin molecules bound to AChBP shows the toxins projecting radially like propeller "blades" from the perimeter of the donut-shaped AChBP, the toxin molecules should increase the frictional resistance and thereby alter the hydrodynamic properties of the complex. alpha-Bungarotoxin binding had little effect on the frictional coefficients of AChBP measured by analytical ultracentrifugation, suggesting that the bound toxins are flexible. To support this conclusion, we measured the anisotropy decay of four site-specifically labeled alpha-cobratoxins (conjugated at positions Lys(23), Lys(35), Lys(49), and Lys(69)) bound to AChBP and free in solution and compared their anisotropy decay properties with fluorescently labeled cysteine mutants of AChBP. The results indicated that the core of the toxin molecule is relatively flexible when bound to AChBP. When hydrodynamic and anisotropy decay analyses are taken together, they establish that only one face of the second loop of the alpha-neurotoxin is immobilized significantly by its binding. The results indicate that bound alpha-neurotoxin is not rigidly oriented on the surface of AChBP but rather exhibits segmental motion by virtue of flexibility in its fingerlike structure. PMID:16342951
Alpha-decay properties of /sup 205-208/Fr: Identification of 206Fr/sup m/
Alpha-particle and γ-ray spectral measurements were made for /sup 205-208/Fr. A new a emitter (T/sub 1/2/ = 0.7 +- 0.1 sec and E/sub a/ = 6.930 +- 0.005 MeV) was observed and identified with the decay of a previously unknown isomer in 206Fr. From the a particle and g ray intensities, a decay branching ratios were deduced for /sup 205-208/Fr utilizing available information concerning the nuclides' (electron capture+positron) decay properties. Reduced widths were calculated and compared with those of neighboring nuclei
Ackerstaff, K; Allison, J; Altekamp, N; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Bartoldus, R; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bird, S D; Blobel, Volker; Bloodworth, Ian J; Bobinski, M; Bock, P; Böhme, J; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brown, R M; Burckhart, Helfried J; Burgard, C; Bürgin, R; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Davis, R; De Jong, S; del Pozo, L A; de Roeck, A; Desch, Klaus; Dienes, B; Dixit, M S; Doucet, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Eatough, D; Estabrooks, P G; Etzion, E; Evans, H G; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Fiedler, F; Fierro, M; Fischer, H M; Fleck, I; Folman, R; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon, J; Gascon-Shotkin, S M; Geich-Gimbel, C; Geralis, T; Giacomelli, G; Giacomelli, P; Gibson, V; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Gross, E; Grunhaus, Jacob; Gruwé, M; Hanson, G G; Hansroul, M; Hapke, M; Hargrove, C K; Hartmann, C; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herndon, M; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hillier, S J; Hobson, P R; Höcker, Andreas; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Joly, A; Jones, C R; Jovanovic, P; Junk, T R; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Koetke, D S; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kyberd, P; Lafferty, G D; Lanske, D; Lauber, J; Lautenschlager, S R; Lawson, I; Layter, J G; Lazic, D; Lee, A M; Lefebvre, E; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mannelli, M; Marcellini, S; Markopoulos, C; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Menke, S; Merritt, F S; Mes, H; Meyer, J; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mir, R; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nellen, B; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Oreglia, M J; Orito, S; Pálinkás, J; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharf, F; Scharff-Hansen, P; Schieck, J; Schmitt, B; Schmitt, S; Schöning, A; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Sittler, A; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Sproston, M; Stahl, A; Stephens, K; Steuerer, J; Stoll, K; Strom, D; Ströhmer, R; Tafirout, R; Talbot, S D; Tanaka, S; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomson, M A; Von Törne, E; Torrence, E; Towers, S; Trigger, I; Trócsányi, Z L; Tsur, E; Turcot, A S; Turner-Watson, M F; Van Kooten, R; Vannerem, P; Verzocchi, M; Vikas, P; Voss, H; Wäckerle, F; Wagner, A; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Yekutieli, G; Zacek, V; Zer-Zion, D
1999-01-01
The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Operator Product Expansion a simultaneous determination of the strong coupling constant alpha_s, the non-perturbative operators of dimension 6 and 8 and of the gluon condensate has been performed. Different perturbative descriptions have been compared to the data. The Contour Improved Fixed Order Perturbation Theory gives alpha_s(mtau**2) = 0.348 +- 0.009 +- 0.019 at the tau-mass scale and alpha_s(mz**2) = 0.1219 +- 0.0010 +- 0.0017 at the Z-mass scale. The values obtained for alpha_s(mz**2) using Fixed Order Perturbation Theory or Renormalon Chain Resummation are 2.3% and 4.1% smaller, respectively. The running of the strong coupling between s_0 ~1.3 GeV**2 and s_0 = mtau**2 has been tested from direct fits to the integrated differential hadronic decay rate R_tau. A test of the saturation of QCD sum rules at the tau-mass scale has been...
Structure effects in the region of superheavy elements via the $\\alpha$-decay chain of $^{293}$118
Gupta, Raj K; Kumar, Rajesh; Balasubramaniam, M; Scheid, W; 10.1088/0954-3899/28/11/310
2011-01-01
The $\\alpha$-decay chain of $^{293}$118, first proposed in the Berkeley cold fusion experiment $^{208}$Pb($^{86}$Kr,1n) and now retracted, is calculated by using the preformed cluster model (PCM) of one of us (RKG). Also, the possible branchings of $\\alpha$-particles to heavier cluster decays of all the parents in this chain are calculated for the first time. The calculated Q-values, penetrabilities and preformation factors for $\\alpha$-decays suggest that the $^{285}$114 nucleus with Z=114, N=171 is a magic nucleus, either due to the magicity of Z=114, or of N=172 or of both. The N=172 is proposed to be a magic number in certain relativistic mean-field calculations, but with Z=120. The calculated cluster decays point to new interesting possibilities of $^{14}$C decay of the $^{281}$112 parent, giving rise to a (reasonably) deformed Z=106, N=161, $^{267}$106 daughter (N=162 being now established as the deformed magic shell) or to a doubly magic $^{48}$Ca cluster emitted from any of the parent nucleus in the $...
Systematic study of $\\alpha$ decay half-lives for even-even nuclei within a two-potential approach
Sun, Xiao-Dong; Li, Xiao-Hua
2015-01-01
$\\alpha$ decay is a common and important process for natural radioactivity of heavy and superheavy nuclei. The $\\alpha$ decay half-lives for even-even nuclei from Z=62 to Z=118 are systematically researched based on the two-potential approach with a quasi-stationary state approximation. To describe the deviations between experimental half-lives and calculated results due to the nuclear shell structure, a hindrance factor related with $\\alpha$ particle preformation probability is introduced. Our results can well reproduce the experimental data equally to the density-dependent cluster model and the generalized liquid drop model. We also study the isospin effect of nuclear potential in this work. Considering the isospin effect the calculated results improved about 7.3$\\%$.
Hansen, J.W. (Risoe National Lab., Roskilde (Denmark)); Olsen, K.J. (University Hospital of Copenhagen, Herlev (Denmark))
1989-01-01
Efforts have been made to develop a model that will predict time-dependent decay in radiation-induced free-radical concentration in L-{alpha}-alanine following heavy-charged-particle exposures. The decay rate depends on radiation quality, dose and dose-rate. For low doses, the decay-rate is approx. 0.5 and 1.5% per year following {sup 60}Co {gamma}-ray exposures and Linac-produced X-ray or electron exposures. Decay rates, however, have been found to increase as measured from low average doses, sparse single tracks, of heavy charged particles. We have compared measured decay after exposures to low average doses from high-LET particles with predicted decay calculated as function of particle velocity and charge and detector parameters. The predicted decay is obtained by folding measured decay after Linac-produced electron exposures of very high doses into the calculated dose distribution around the heavy ion's path. Preliminary results show agreement between the experimental data and results obtained from this model, within the experimental uncertainty. (author).
Joseph, Deepthy Maria; Ashok, Nithu; Joseph, Antony
2016-01-01
Employing the effective liquid drop model (ELDM), half-lives of proton and alpha decays and probable cluster decays are computed and analyzed for different proton-rich and neutron-rich isotopes of Rhenium. The investigation fortifies the phenomenon of cluster radioactivity (CR) in rare earth nuclei and also affirms the pivotal role played by neutron magicity in cluster decays. ELDM data is compared with that of universal decay law (UDL) model and found to be more efficient than the latter one. Apparently, cluster emissions slacken as the neutron number of daughter nucleus goes up and the linear nature of Geiger-Nuttall (G-N) plots stays unaltered even if the surface potential is incorporated.
Santhosh, K P; Nithya, C; Priyanka, B
2016-01-01
An intense study of the alpha decay properties of the isotopes of superheavy element Z=113 have been performed within the Coulomb and proximity potential model for deformed nuclei (CPPMDN) within the wide range 255 l.e. A l.e. 314. The predicted alpha decay half lives of $^{278}$113 and $^{282}$113 and the alpha half lives of their decay products are in good agreement with the experimental data. 6{\\alpha) chains and 4{\\alpha} chains predicted respectively for $^{278}$113 and $^{282}$113 are in agreement with the experimental observation. Our study shows that the isotopes in the mass range 278 l.e. A l.e. 286 will survive fission and can be synthesized and detected in the laboratory via alpha decay. In our study, we have predicted 6{\\alpha} chains from $^{279}$113, 4{\\alpha} chains from $^{286}$113, 3{\\alpha} chains from $^{280,281,283}$113, 2{\\alpha} chains from $^{284}$113 and 1{\\alpha} chain from $^{285}$113. We hope that these predictions will be a guideline for future experimental investigations.
Mitamura, Hisayoshi; Matsumoto, Seiichiro; Tsuboi, Takashi; Hashimoto, Masaaki; Togashi, Yoshihiro; Kanazawa, Hiroyuki (Japan Atomic Energy Research Inst., Ibaraki (Japan)); Stewart, M.W.A.; Vance, E.R.; Hart, K.P.; Ball, C.J. (Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales (Australia). Lucas Heights Research Labs.); White, T.J.
1994-09-01
A polyphase titanate ceramic incorporating sodium-free simulated high-level nuclear waste was doped with 0.91 wt% of [sup 224]Cm to accelerate the effects of long-term self-irradiation arising from [alpha] decays. The ceramic included three main constituent minerals: hollandite, perovskite, and zirconolite, with some minor phases. Although hollandite showed the broadening of its X-ray diffraction lines and small lattice parameter changes during damage in growth, the unit cell was substantially unaltered. Perovskite and zirconolite, which are the primary hosts of curium, showed 2.7% and 2.6% expansions, respectively, of their unit cell volumes after a dose of 12 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1]. Volume swelling due to damage in growth caused an exponential (almost linear) decrease in density, which reached 1.7% after a dose of 12.4 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1]. Leach tests on samples that had incurred doses of 2.0 [times] 10[sup 17] and 4.5 [times] 10[sup 17] [alpha] decays[center dot]g[sup [minus]1] showed that the rates of dissolution of cesium and barium were similar to analogous leach rates from the equivalent cold ceramic, while strontium and calcium leach rates were 2--15 times higher. Although the cerium, molybdenum, strontium, and calcium leach rates in the present material were similar to those in the curium-doped sodium-bearing titanate ceramic reported previously, the cesium leach rate was 3--8 times lower.
Measurement of the CKM Angle Alpha at the BABAR Detector Using B Meson Decays to Rho Final States
Mihalyi, Attila; /Wisconsin U., Madison
2006-10-16
This thesis contains the results of an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} using 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a fitted signal yield of 617 {+-} 52 events, the longitudinal polarizations fraction, f{sub L}, of the decay is measured to be 0.978 {+-} 0.014(stat){sub -0.029}{sup +0.021}(syst). The nearly fully longitudinal dominance of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay allows for a measurement of the time dependent CP parameters S{sub L} and C{sub L}, where the first parameter is sensitive to mixing induced CP violation and the second one to direct CP violation. From the same signal yield, these values are found to be S{sub L} = -0.33 {+-} 0.24(stat){sub -0.14}{sup +0.08}(syst) and C{sub L} = - 0.03 {+-} 0.18(stat) {+-} 0.09(syst). The CKM angle {alpha} is then determined, using these results and the branching fractions and polarizations of the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} and B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. This measurement is done with an isospin analysis, in which a triangle is constructed from the isospin amplitudes of these three decay modes. A {chi}{sup 2} expression that includes the measured quantities expressed as the lengths of the sides of the isospin triangles is constructed and minimized to determine a confidence level on {alpha}. Selecting the solution compatible with the Standard Model, one obtains {alpha} = 100{sup o} {+-} 13{sup o}.
New evaluation of alpha decay half-life of 190Pt isotope for the Pt-Os dating system
A semiempirical model based on the quantum mechanical tunnelling mechanism of alpha emission from nuclei has been used to evaluate the half-life of the Pt isotopes. For the important naturally occurring 190Pt isotope, the radiogenic parent in the 190 Pt → 186Os dating system, the model yielded a half-life value of (3.7± 0.3) versus 1011 y. This is comparable to (3.2±0.1) versus 1011 y which was obtained in the last direct counting experiment to measure the alpha activity of 190Pt (Tavares and Terranova, Rad. Measurem. 27 (1997) 19). A literature survey of available alpha decay half-life values for 190Pt isotope is also reported. The significant discrepancies found between data obtained by direct counting, indirect geological methods and different calculation models are analysed and discussed. (author)
Dynamical aspects of a wave packet which tunnels through a potential barrier have been studied by solving numerically the time dependent Schroedinger equation in one and two dimensions. Concerning potentials with several wells, this approach have shown the strong influence of the details of the potential upon the tunneling probabilities (resonance). Alpha decay (decay of a quasi-stationary state) was studied also by solving this equation. A time dependent decay rate was observed. In particular, there is a transient time before the asymptotic limit is reached. A new method was proposed to determine tunneling times. Lastly, this procedure was applied in the case of the symmetric fission. Fission rates of vibrational quasi-stationary states of different energies were calculated. Transient times and saddle to scission times were derived
Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient VMAS/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, τc is presented for all possible cases of spontaneous nuclear break-up such that -7.30 10 τc [S] 10(τ/τc) > -17.0, where τ is the total half-life of the parent nucleus. (author)
Yields of Gamma- and X-Ray Radiation of Alpha-Decays of 235U
Precise knowledge of gamma- and X-rays emission probabilities of uranium isotopes is vital for accurate gamma-spectrometric determination of the isotopic composition and quantity of uranium. The peak intensity ratio methods employing high resolution gammaspectrometry and intrinsic efficiency calibration approach are known to provide most accurate and reliable isotopic information. When applied to unshielded and moderately shielded material, these methods largely benefit from de-convolution of the 90-100 keV narrow spectral interval, which contains intense gamma- and X-ray lines of major uranium isotopes 235U and 238U. These are the 92.37 keV and 92.79 keV gamma-rays of 238U/234Th, and the 93.35 keV ThKα1 X-rays from alpha-decay of 235U. Although the emission probability ratios of these lines were accurately established, their absolute yields are still lacking accuracy. For instance, as resulted from recent study, the yields of 234Th lines become corrected by 30%, compared with their previous values. This consequently raised a question regarding validity of the yield data for the 93.35 keV line of 235U and triggered the present experimental study. This study was later extended to the reexamination of emission probabilities of other 235U gamma-lines with energies above 205 keV. The experimental data used in the current work was collected using SRM 969 and CRM 146 reference uranium samples. (author)
Larios, Adam; Titi, Edriss S
2010-01-01
We establish global existence and uniqueness theorems for the two-dimensional non-diffusive Boussinesq system with viscosity only in the horizontal direction, which arises in Ocean dynamics. This work improves the global well-posedness results established recently by R. Danchin and M. Paicu for the Boussinesq system with anisotropic viscosity and zero diffusion. Although we follow some of their ideas, in proving the uniqueness result, we have used an alternative approach by writing the transported temperature (density) as $\\theta = \\Delta\\xi$ and adapting the techniques of V. Yudovich for the 2D incompressible Euler equations. This new idea allows us to establish uniqueness results with fewer assumptions on the initial data for the transported quantity $\\theta$. Furthermore, this new technique allows us to establish uniqueness results without having to resort to the paraproduct calculus of J. Bony. We also propose an inviscid $\\alpha$-regularization for the two-dimensional inviscid, non-diffusive Boussinesq s...
Shestermanov, K.E.; Vasiliev, A.N; /Serpukhov, IHEP; Butler, J.; Derevschikov, A.A.; Kasper, P.; Kiselev, V.V.; Kravtsov, V.I.; Kubota, Y.; Kutschke, R.; Matulenko, Y.A.; Minaev, N.G.; /Serpukhov, IHEP /Fermilab /Minnesota U. /Syracuse U. /INFN, Milan
2005-12-01
A precise measurement of the angle {alpha} in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract {alpha} is provided by B{sup 0} {yields} {rho}{pi} decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tre and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on {alpha} better than 5{sup o}.
Experimental determination of the decay constant Alpha in the zero power reactor SUR 100 BE
The paper discusses experiments with a pulsed source and Rossi-Alpha experiments. In the first case, the effects of higher harmonies and detector position are investigated. In the Rossi-Alpha method, the interest was centered on the correlation between reactivity source strength and method of measurement. (RW/AK)
Study of the decay B0(B0bar)-->rho+rho-, and constraints on the CKM angle alpha
Aubert, Bernard; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Le Clerc, C; Lynch, G; Merchant, A M; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel, G; de Monchenault; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Convery, M R; Cristinziani, M; De, G; Nardo; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della, G; Ricca; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H
2004-01-01
Using a data sample of 89 million Y(4s)-->B0B0bar decays collected with the BaBar detector at the PEP-II asymmetric B Factory at SLAC, we measure the B0(B0bar)-->rho+rho- branching fraction as $(30\\pm 4 stat \\pm 5 syst) \\times 10^{-6}$ and a longitudinal polarization fraction of $f_L = 0.99 \\pm 0.03 stat ^{+0.04}_{-0.03} syst$. We measure the time-dependent-asymmetry parameters of the longitudinally polarized component of this decay as $C_L = -0.17\\pm 0.27 stat \\pm 0.14 syst$ and ${S_L} = -0.42 \\pm 0.42 stat \\pm 0.14 syst$. We present constraints on the CKM angle $\\alpha$.
Wei, Xing
2016-01-01
We investigate numerically the decay of isotropic, rotating, magnetohydrodynamic (MHD), and rotating MHD flows in a periodic box. The Reynolds number $Re$ defined with the box size and the initial velocity is $100$ at which the flows are in a weakly nonlinear regime, i.e. not laminar but far away from the fully turbulent state. The decay of isotropic flow has two stages, the first stage for the development of small scales and the second stage for the viscous dissipation. In the rapidly rotating flow, fast rotation induces the inertial wave and causes the large-scale structure to inhibit the development of the first stage and retard the flow decay. In the MHD flow, the imposed field also causes the large-scale structure but facilitates the flow decay in the first stage because of the energy conversion from flow to magnetic field. Magnetic Reynolds number $Rm$ is important for the dynamics of the MHD flow, namely a high $Rm$ induces the Alfv\\'en wave but a low $Rm$ cannot. In the rotating MHD flow, slower rotat...
Properties of the Alpha Decay Chain Nuclei of 310126, 292120 and 298114
WANG Ting-Tai; JIANG Wei-Zhou; ZHANG Wei; WANG Kun; ZHU Zhi-Yuan
2004-01-01
@@ The properties of the α decay nuclei of 310126, 292120 and 298 114 are investigated in the deformed relativistic meanfield model. The nuclear properties are investigated with the TMA and NL-Z2 parameter sets, and comparedwith Moller's result [At. Data Nucl. Data Tables 59 (1995) 185]. The results show that the α decay energy increases systematically with the increasing proton number. Meanwhile, the a decay energy has a minimum value at the point of shell closure. It is also found that among the three nuclei, 292120 is more possible to be the next doubly magic nucleus.
Improved Determination of the CKM Angle alpha from B to pi pi decays
UTfit Collaboration; Bona, M.; Ciuchini, M.; Franco, E.; Lubicz, V.; Martinelli, G; Parodi, F.; Pierini, M.; Roudeau, P.; Schiavi, C.; Silvestrini, L.; Sordini, V.; Stocchi, A.; Vagnoni, V.
2007-01-01
Motivated by a recent paper that compares the results of the analysis of the CKM angle alpha in the frequentist and in the Bayesian approaches, we have reconsidered the information on the hadronic amplitudes, which helps constraining the value of alpha in the Standard Model. We find that the Bayesian method gives consistent results irrespective of the parametrisation of the hadronic amplitudes and that the results of the frequentist and Bayesian approaches are equivalent when comparing meanin...
A Study of B0 to rho+rho- Decays and Constraints on theCKM Angle alpha
Aubert, B.
2007-05-16
The authors present results from an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decays using (383.6 {+-} 4.2) x 10{sup 6} B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The measurements of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} branching fraction, longitudinal polarization fraction f{sub L}, and the CP-violating parameters S{sub long} and C{sub long} are: {Beta}(B{sup 0} {yields} {rho}{sup +}{rho}{sup -}) = (25.5 {+-} 2.1(stat){sub -3.9}{sup +3.6}(syst)) x 10{sup -6}, f{sub L} = 0.992 {+-} 0.024(stat){sub -0.013}{sup +0.026}(syst), S{sub long} = -0.17 {+-} 0.20(stat){sub -0.06}{sup +0.05}(syst), C{sub long} = 0.01 {+-} 0.15(stat) {+-} 0.06(syst). The authors determine the unitarity triangle angle {alpha}, using an isospin analysis of B {yields} {rho}{rho} decays. One of the two solutions, {alpha} = [73.1, 117.0]{sup o} at 68% CL is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry based approach.
A Study of B0 to rho+rho- Decays and Constraints on the CKM Angle alpha
Aubert, B; Boutigny, D; Karyotakis, Yu; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Graugès-Pous, E; López, L; Palano, A; Eigen, G; Ofte, I; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes-Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo-Sánchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schröder, T; Steinke, M; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Bequilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F R; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Wright, D M; Lange D J; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Fisher, P H; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, Gallieno; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Lo Secco,J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Chauveau, J; David, P; Del Buono, L; De La Vaissière, C; Hamon, O; Hartfiel, B L; Leruste, P; Malcles, J; Ocariz, J; Pérez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Röthel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H
2007-01-01
We present results from an analysis of B0 to rho+rho- decays using 383.6 million BB-bar pairs collected by the BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. The measurements of the B0 to rho+rho- branching fraction, longitudinal polarization fraction f_L, and the CP-violating parameters S_{long} and C_{long} are: B(B0-> rho+rho-) = (25.5 +/- 2.1 (stat) +3.6/-3.9 (syst))*10^-6 f_L = 0.992 +/- 0.024 (stat) +0.026/-0.013 (syst) S_{long} = -0.17 +/- 0.20 (stat) +0.05/-0.06 (syst) C_{long} = 0.01 +/- 0.15 (stat) +/- 0.06 (syst) We determine the unitarity triangle angle alpha, using an isospin analysis of B to rhorho decays. One of the two solutions, alpha = [73.1, 117.0] degrees at 68% CL is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry based approach.
New search for correlated e{sup +}e{sup -} pairs in the {alpha} decay of {sup 241}Am
Bernabei, R.; Belli, P.; Di Marco, A. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Fisica, Rome (Italy); Cappella, F.; D' Angelo, A.; Incicchitti, A. [INFN, Sezione Roma, Rome (Italy); Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R.; Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Dai, C.J.; He, H.L.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy, IHEP, Beijing (China); Montecchia, F. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipartimento di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Tretyak, V.I. [Institute for Nuclear Research, Kyiv (Ukraine); Ye, Z.P. [Chinese Academy, IHEP, Beijing (China); University of Jing Gangshan, Jiangxi (China)
2013-05-15
A new search for production of correlated e{sup +}e{sup -} pairs in the {alpha} decay of {sup 241}Am has been carried out deep underground at the Gran Sasso National Laboratory of the INFN by using pairs of NaI(Tl) detectors of the DAMA/LIBRA set-up. The experimental data show an excess of double coincidences of events with energy around 511keV in faced pairs of detectors, which are not explained by known side reactions. This measured excess gives a relative activity {lambda} = (4.70{+-}0.63) x 10{sup -9} for the Internal Pair Production (IPP) with respect to the alpha decay of {sup 241}Am; this value is of the same order of magnitude as previous determinations. In a conservative approach the upper limit {lambda} < 5.5 x 10{sup -9} (90% C.L.) can be derived. It is worth noting that this is the first result on IPP obtained in an underground experiment, and that the {lambda} value obtained in the present work is independent of the live-time estimate. (orig.)
Alpha-particle emission probabilities in the decay of {sup 240}Pu
Sibbens, G., E-mail: goedele.sibbens@ec.europa.e [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Pomme, S.; Altzitzoglou, T. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Garcia-Torano, E. [Laboratorio de Metrologia de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Janssen, H.; Dersch, R.; Ott, O. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Martin Sanchez, A. [Departamento de Fisica, Universidad de Extremadura, Badajoz, E-06071 (Spain); Rubio Montero, M.P. [Departamento de Fisica Aplicada, Universidad de Extremadura, Merida, Badajoz, E-06800 (Spain); Loidl, M. [Laboratoire National Henri Becquerel, LNE/CEA-LIST, 91191 Gif-sur-Yvette (France); Coron, N.; Marcillac, P. de [Institut d' Astrophysique Spatiale, CNRS, 91405 Orsay Campus (France); Semkow, T.M. [Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States)
2010-07-15
Sources of enriched {sup 240}Pu were prepared by vacuum evaporation on quartz substrates. High-resolution alpha-particle spectrometry of {sup 240}Pu was performed with high statistical accuracy using silicon detectors and with low statistical accuracy using a bolometer. The alpha-particle emission probabilities of six transitions were derived from the spectra and compared with literature values. Additionally, some alpha-particle emission probabilities were derived from {gamma}-ray intensity measurements with a high-purity germanium detector. The alpha-particle emission probabilities of the three main transitions at 5168.1, 5123.6 and 5021.2 keV were derived from seven aggregate spectra analysed with five different fit functions and the results were compatible with evaluated data. Two additional weak peaks at 4863.5 and 4492.0 keV were fitted separately, using the exponential of a polynomial function to represent the underlying tailing of the larger peaks. The peak at 4655 keV could not be detected by alpha-particle spectrometry, while {gamma}-ray spectrometry confirms that its intensity is much lower than expected from literature.
Description of alpha decay and cluster radioactivity in the dinuclear system model
Kuklin, S. N.; Adamian, G. G.; Antonenko, N. V.
2016-03-01
A unified description of cluster radioactivity and α-decay of cold nuclei in the dinuclear system model is proposed. Quantum dynamical fluctuations along the charge (mass) asymmetry coordinate determine the spectroscopic factor, and tunneling along the relative distance coordinate determines the penetrability of the barrier of the nucleus-nucleus interaction potential. A new method for calculating the spectroscopic factor is proposed. The hindrance factors for the orbital angular momentum transfer are studied. A potential reason for the half-life to deviate from the Geiger-Nuttall law in α-decays of neutron-deficient nuclei 194, 196Rn is found. The fine structure of α-decays of U and Th isotopes is predicted and characterized. The model is used to describe α-decays from the rotational band of even-even nuclei. The known half-lives in the regions of "lead" and "tin" radioactivities are reproduced well, and the most probable cluster yields are predicted. The cluster decay of excited nuclei is discussed. The relation of cluster radioactivity to spontaneous fission and highly deformed nuclear states is analyzed.
Duarte, S.B.; Tavares, O.A.P.; Guzman, F.; Dimarco, A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Garcia, F. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Rodriguez, O. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Instituto Superior de Ciencias e Tecnologia Nucleares, La Habana (Cuba); Goncalves, M. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)
2002-01-01
Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient V{sub MAS}/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, {tau}{sub c} is presented for all possible cases of spontaneous nuclear break-up such that -7.30 <{approx_equal} log{sub 10} {tau}{sub c} [S] <{approx_equal} 27.50 and log {sub 10}({tau}/{tau}{sub c}) > -17.0, where {tau} is the total half-life of the parent nucleus. (author)
Ground State Properties of New Element Z = 113 and Its Alpha Decay Chain
TAI Fei; CHEN Ding-Han; XU Chang; REN Zhong-Zhou
2005-01-01
@@ We investigate the ground state properties of the new element 278113 and of the α-decay chain with different models, where the new element Z = 113 has been produced at RIKEN in Japan by cold-fusion reaction [Morita et al.J.Phys.Soc.Jpn.73 (2004) 2593].The experimental decay energies are reproduced by the deformed relativistic mean-field model, by the Skyrme-Hartree-Fock (SHF) model, and by the macroscopic-microscopic model.Theoretical half-lives also reasonably agree with the data.Calculations further show that prolate deformation is important for the ground states of the nuclei in the α-decay chain of 278113.The common points and differences among different models are compared and discussed.
Wang, Chi-Jen; Han, Yong; Walen, Holly; Russell, Selena M.; Thiel, Patricia A.; Evans, James W.
2013-10-01
Submonolayer homoepitaxial fcc (110) systems display behavior reflecting strong anisotropy at lower temperatures, including one-dimensional decay during Ostwald ripening of rectangular islands maintaining constant width in the (001) direction. To appropriately describe this behavior, we first develop a refined continuum Burton-Cabrera-Frank formalism, which accounts for a lack of equilibration of island shape and importantly also for inhibited incorporation of adatoms at almost-faceted (1¯10) island edges through effective kinetic coefficients. This formalism is shown to describe accurately the adatom diffusion fluxes between islands and thus island evolution for a complex experimental island configuration, as confirmed by matching results from realistic atomistic simulations for this configuration. This approach also elucidates basic dependencies of flux on island geometry and temperature. Second, a further refinement is presented incorporating separate terrace and edge adatom density fields either in a continuum setting or alternatively in a spatially discrete diffusion equation setting. The second approach allows more flexibility and accuracy in accounting for edge-diffusion kinetics including corner rounding, a lack of equilibration of the edge adatom density at (1¯10) island edges, and the effect of rare kinks on (1¯10) island edges. Finally and significantly, it suggests facile two-way corner rounding at the island periphery during island decay, contrasting the previous picture.
On the decay of compound nuclei following alpha-particle and 12C induced reactions
Multiple coincidence rates have been measured using a detector system consisting of a Ge(Li) spectrometer and eight NaI(Tl) or eight liquid scintillators. Reactions induced by α-particles with energies of 51-55 MeV and 118 MeV 12C ions are studied. The data are analysed to give the first and second central moments of the distribution of the number of γ-rays feeding individual levels in the final nuclei. When these numbers are compared to spin distributions calculated with the statistical model code GROGI the relative importance of dipole and quadrupole deexcitation modes can be ascertained. In particular, in the 122Te(α,4n)122Xe reaction the γ-decay prior to the entry into the ground band is well described as a statistical process proceeding to 50% by dipole and 50% by quadrupole radiation. In the 166Er(α,4n)166Yb and 192Os(α,4n)192Pt reactions the relative amount of quadrupole radiation is larger and it seems that the dipole and quadrupole decay takes place via separate cascades. In the 164Dy(12C,7-8n) reactions the average multiplicity is independent of spin, suggesting that the nucleus forgets the spin of the entry state before the process enters into the ground band. In the 176Yb(12C,8n)180Os reaction, finally, the nucleus difinitely retains memory of the entry state during the decay. In this last case the multiplicity measurement is combined with a γ-ray singles measurement to give an average excitation energy prior to the α-decay and the average moment of inertia characterising the decay of the high-spin states. (orig.)
Microdosimetry of alpha-emitting decay products in tissue using conventional film autoradiography
Presented work describes a practical method using conventional photographic films; specifically, Ilford Pan F Plus 135-36, Black and White, ISO 50 film for obtaining images of alpha tracks. A variety of alpha radiation sources including electrodeposited planchets, Bomarc soil, and samples of bone containing 226Ra were placed directly on the film for up to 3 days. Post-exposure the film was developed using standard darkroom techniques with Kodak D-76 developer for 7 min, stop bath, and fixer. Tracks consisting of five or more grains were counted using an Olympus BX51 microscope at 910 magnification in a 9 cm2 circular field-of-view. Initial analysis shows an efficiency of approximately 34.9 % with an uncertainty in track counts of ±2.4 % for the monoenergetic particles. (author)
On the validity of the Geiger–Nuttall alpha-decay law and its microscopic basis
The Geiger–Nuttall (GN) law relates the partial α-decay half-life with the energy of the escaping α particle and contains for every isotopic chain two experimentally determined coefficients. The expression is supported by several phenomenological approaches, however its coefficients lack a fully microscopic basis. In this paper we will show that: (1) the empirical coefficients that appear in the GN law have a deep physical meaning, and (2) the GN law is successful within the restricted experimental data sets available so far, but is not valid in general. We will show that, when the dependence of logarithm values of the α formation probability on the neutron number is not linear or constant, the GN law is broken. For the α decay of neutron-deficient nucleus 186Po, the difference between the experimental half-life and that predicted by the GN law is as large as one order of magnitude
Zhu Jian
2010-01-01
Full Text Available Abstract Fluorescence quenching spectrometry was applied to study the interactions between gold colloidal nanoparticles and alpha-fetoprotein (AFP. Experimental results show that the gold nanoparticles can quench the fluorescence emission of adsorbed AFP effectively. Furthermore, the intensity of fluorescence emission peak decreases monotonously with the increasing gold nanoparticles content. A mechanism based on surface plasmon resonance–induced non-radiative decay was investigated to illuminate the effect of a dielectric shell on the fluorescence quenching ability of gold nanoparticles. The calculation results show that the increasing dielectric shell thickness may improve the monochromaticity of fluorescence quenching. However, high energy transfer efficiency can be obtained within a wide wavelength band by coating a thinner dielectric shell.
The systematics of the experimental data of alpha-decay fine structure in the even-even nuclei above lead are examined. The representation of relative branching ratios (b.r.) and hindrance factors (HF) for the 2+1, 4+1, and 6+1 states within the valence correlation schemes (as a function of NpNn or P = NpNn/(Np + Nn)) proves useful, as it provides smooth trajectories that can be discussed in parallel with the development of collectivity. It is shown that practically all recent theoretical calculations are not able to account for some of the most conspicuous features presented by the evolution of the branching ratios and hindrance factors. These are: a practically exponential increase of the b.r.'s and HF's for the 2+1 state of collective nuclei (above P approx. 4.0); a pronounced maximum around P approx. 7.5 of the same quantities for the 4+1 state, a region where these nuclei have usually been considered as well deformed rotors; and the decrease of these quantities for the 6+1 state in the interval of P from 4.0 to about 8.0. The observed evolutions of these fine structure quantities do not appear to be correlated with different structure indicators deduced from the low-lying level schemes, with the exception of the HF of the 2+ state which is reasonably well correlated with a parameter that describes the nuclear rigidity, indicating the necessity of going beyond the rigid rotor description of the nuclei considered in this study. It is also necessary that a simultaneous description of both electromagnetic transitions and alpha decay fine structure data is achieved by the theoretical calculations.
Meirellesfilho, C.; Liang, Edison P.
1994-01-01
There has been, recently, a revival of the stability problem of accretion disks. Much of this renewed interest is due to recent observational data on transient soft X-ray novae, which are low-mass X-ray binaries. It is widely believed that nonsteady mass transfer from the secondary onto the compact primary, through an accretion disk, is the reason for the observed spectacular events in the form of often repetitive outbursts, with recurrence times ranging from 1 to 60 yr and duration time on the scale of months. Though not having reached yet a consensus about the nature of the mechanism that regulates the mass transfer, the disk thermal instability model seems to be favored by the fact that the rise in the hard X-ray luminosity is prior to the rise in the soft X-ray luminosity, while the mass transfer instability model seems to be hindered by the fact that the luminosity during quiescence is unable to trigger the thermal instability. However, it should be stressed that, remarkably, the X-ray light curves of these X-ray novae all show overall exponential decays, a feature quite difficult to reproduce in the framework of the viscous disk model, which yields powerlike luminosity decay. Taking into account this observational constraint, we have studied the temporal evolution of perturbations in the accretion rate, under the assumption that alpha is radial and parameter dependent. The chosen dependence is such that the model can reproduce limit cycle behavior (the system is locally unstable but globally stable). However, the kind of dependence we are looking for in alpha does not allow us to use the usual Shakura and Sunyaev procedure in the sense that we no longer can obtain a linearized continuity equation without explicit dependence on the accretion rate. This is so because now we cannot eliminate the accretion rate by using the angular momentum conservation equation.
Bolometric detection of the recoil spectrum in the alpha decay of 210Po
Bolometers at low temperature are being developed as particle spectrometers and potential detectors of dark matter particles through the measurement of recoil energies. A successful observation of the recoil spectrum from a Po electrodeposited source was made for the first time with the use of a 2 mm3 composite-composite diamond bolometer operated in a 300 mK cryostat. The measured recoil ratio is 0.98±0.06 recoil/alpha above 50 keV, with the well defined peak in the spectrum at 101±2.5 keV. ((orig.))
α-decay damage and recrystallization in natural zircon (with dose ranging from 0.06 to 23.3x1018 α-events g-1) were studied using polarized reflection infrared spectroscopy. The experimental results show that α-decay damage leads to a gradual decrease in reflectivity and a loss of anisotropy of IR spectra. Recrystallization of damaged zircon is found as a multi-stage process with a strong dependence on the initial degree of damage. In weakly and moderately damaged samples the major recrystallization takes place near 1000 K. Annealed samples recrystallize epitaxially along their original crystallographic orientations. A highly damaged zircon with radiation dose of 15.9x1018 α-events g-1 decomposes into SiO2 and ZrO2 near 1100 K. In this sample the growth of ZrSiO4 from the binary oxides occurs between 1400 and 1500 K. An additional IR signal peaked near 790 cm-1 is detected in moderately damaged samples annealed at temperatures higher than 800 K. This peak is sharp and isotropic. The peak tends to disappear at temperatures above 1400 K. This signal may be related to an unknown intermediate phase caused by heating of radiation-damaged zircon. Alternatively, the signal may be due to the structural distortions near the boundaries between the amorphized and crystalline regions. (author)
Ahmad, I.; Davids, C.; Janssens, R.V.F. [and others
1995-08-01
The interaction between coexisting shapes in nuclei near closed shells was of great interest in the past decade. Excited 0{sup +} states at low energy can often be identified as the bandheads of structures with differing shapes built on those states, These structures were identified in {sup 190-198}Pb via beta decay and alpha decay {open_quotes}fine structure{close_quotes} studies. Coexistence of different shapes in Pb nuclei was predicted by Nilsson-Strutinsky calculations, in which both the oblate and prolate minima were predicted to have excitation energies near 1 MeV. It was our intention to continue the systematic study of the Pb nuclides by searching for excited O{sup +} states in {sup 188}Pb by observing the fine structure in the alpha decay of {sup 192}Po.
Belloni, Fabio [Institute for Transuranium Elements, European Commission, Joint Research Centre, Postfach 2340, Karlsruhe (Germany)
2016-02-15
The influence of the electron environment on the α decay is elucidated. Within the frame of a simple model based on the generalized Thomas-Fermi theory of the atom, it is shown that the increase of the electron density around the parent nucleus drives a mechanism which shortens the lifetime. Numerical results are provided for {sup 144}Nd, {sup 154}Yb and {sup 210}Po. Depending on the nuclide, fractional lifetime reduction relative to the bare nucleus is of the order of 0.1-1% in free ions, neutral atoms and ordinary matter, but may reach up to 10% at matter densities as high as 10{sup 4}g/cm{sup 3}, in a high-Z matrix. The effect induced by means of state-of-the-art compression techniques, although much smaller than previously found, would however be measurable. The extent of the effect in ultra-high-density stellar environments might become significant and would deserve further investigation. (orig.)
Akrawy, M.Z.; Alexander, G.; Allison, J.; Allport, P.P.; Anderson, K.J.; Armitage, J.C.; Arnison, G.T.J.; Ashton, P.; Azuelos, G.; Baines, J.T.M.; Ball, A.H.; Banks, J.; Barker, G.J.; Barlow, R.J.; Batley, J.R.; Beck, A.; Becker, J.; Behnke, T.; Bell, K.W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I.J.; Bock, P.; Breuker, H.; Brown, R.M.; Brun, R.; Buijs, A.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Chrin, J.T.M.; Clarke, P.E.L.; Cohen, I.; Collins, W.J.; Conboy, J.E.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G.M.; Debu, P.; Deninno, M.M.; Dieckmann, A.; Dittmar, M.; Dixit, M.S.; Duchovni, E.; Duerdoth, I.P.; Dumans, D.J.P.; Elcombe, P.A.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fischer, H.M.; Fong, D.G.; French, M.T.; Fukunaga, C.; Gaidot, A.; Ganel, O.; Gary, J.W.; Gascon, J.; Geddes, N.I.; Gee, C.N.P.; Geich-Gimbel, C.; Gensler, S.W.; Gentit, F.X.; Giacomelli, G.; G; OPAL Collaboration
1991-02-01
Jet production rates in hadronic Z{sup 0} decays are studied using four different recombination schemes to define resolvable jets. The strong coupling constant {alpha}{sub s}(Msub(Z{sup 0})) is determined in fits of the corresponding O({alpha}{sub s}{sup 2}) QCD calculations to the differential 2-jet distributions D{sub 2}(y). Hadronisation corrections and renormalisation scale uncertainties are found to be different for each recombination scheme. Within their overall systematic uncertainties, the four schemes yield consistent values of {alpha}{sub s}(Msub(Z{sup 0})), leading to a final result of {alpha}{sub s}(Msub(Z{sup 0}))=0.118{plus minus}0.008. The error includes the experimental uncertainties ({plus minus}0.003), uncertainties of hadronisation corrections and of the degree of parton virtualities to which the data are corrected, as well as the uncertainty of choosing the renormalisation scale. (orig.).
Simakin, A V
2011-01-01
Experimental results are presented on laser-induced accelerated alpha-decay of Uranium-232 nuclei under laser exposure of Au nanoparticles in aqueous solutions of its salt. It is demonstrated that the decrease of alpha-activity strongly depends on the peak intensity of the laser radiation in the liquid and is highest at several terawatt per square centimeter. The decrease of alpha-activity of the exposed solutions is accompanied by the deviation of gamma-activities of daughter nuclides of Uranium-232 from their equilibrium values. Possible mechanisms of the laser influence on the alpha-activity are discussed on the basis of the amplification of the electric field of laser wave on metallic nanoparticles.
Ahamad, Shakeb; Patra, S K
2012-01-01
The ground state and first intrinsic excited state of superheavy nuclei with Z=120 and N=160-204 are investigated using both non-relativistic Skyrme-Hartree-Fock and the axially deformed Relativistic Mean Field formalisms. We employ a simple BCS pairing approach for calculating the energy contribution from pairing interaction. The results for isotopic chain of binding energy, quadrupole deformation parameter, two neutron separation energies and some other observables are compared with the FRDM and some recent macroscopic-microscopic calculations. We predict superdeformed ground state solutions for almost all the isotopes. Considering the possibility of magic neutron number, two different mode of \\alpha-decay chains (292)120 and (304)120 are also studied within these frameworks. The Q_{\\alpha}-values and the half-life T^{\\alpha}_{1/2} for these two different mode of decay chains are compared with FRDM and recent macroscopic-microscopic calculations. The calculation is extended for the \\alpha-decay chains of 29...
In glass-forming melts the decay of structural fluctuation shows the well known transition from beta-relaxation (von-Schweidler law with exponent b) to alpha-decay (KWW law with exponent beta). Here we present results from molecular dynamics simulations for a metallic glass forming Ni0.5Zr0.5 model aimed at giving an understanding of this transition on the atomistic scale. At the considered temperature below mode coupling Tc, the dynamics of the system can be interpreted by residence of the particles in their neighbour cages and escape from the cages as rare processes. Our analysis yields that the fraction of residing particles is characterized by a hierarchical law in time, with von-Schweidler b explicitly related to the exponent of this law. In the alpha-decay regime the stretching exponent reflects, in addition, floating of the cages due to strain effects of escaped particles. Accordingly, the change from beta-relaxation to alpha-decay indicates the transition from low to large fraction of escaped particles.
Kim, C S
1999-01-01
At the first PPPP workshop, I gave a review talk on physics of B and CP-phases. In my talk, I explained DRG method and our extension to extract CP angles $\\alpha$ and $\\gamma$ from measurements of the decay rates of $B_{d,s}^0 discrete ambiguities are removed, fewer assumptions are necessary, and the method works even if all strong phases vanish. I also talked on several other topics.
Diaz-Cruz, J L [Cuerpo Academico de PartIculas, Campos y Relatividad de la BUAP (Mexico); Felix-Beltran, O [Instituto de Fisica, UNAM, Apdo. Postal 20-364, Mexico 01000 D.F. (Mexico); Hernandez-Sanchez, J [Universidad Autonoma del Estado de Hidalgo, Carretera a Pachuca Tulancingo Km. 4.5, C. U., C.P. 42020, Pachuca Hidalgo (Mexico); Barradas-Guevara, E [Cuerpo Academico de PartIculas, Campos y Relatividad de la BUAP (Mexico)
2006-05-15
The vertex H{sup +}{sub {alpha}} {yields} W{sup -}h{sup 0}{sub s}s, involving the gauge boson W{sup {+-}} and the charged (H{sup {+-}}{sub {alpha}}) and neutral Higgs bosons (h{sup 0}{sub s}s), arises within the context of many extensions of the SM, and it can be used to probe the quantum numbers of the Higgs multiplet. After presenting a general discussion for the expected form of this vertex for arbitrary Higgs representations, we discuss its strength for an extended MSSM with one complex triplet. We find that in this model, there are regions of parameters where the decay H{sup +}{sub {alpha}} {yields} W{sup +}h{sup 0}{sub s}s, is kinematically allowed, and reaches Branching Ratios (BR) that may be detectable, thus allowing to test the properties of the Higgs sector.
Sun, Xiao-Dong; Li, Xiao-Hua
2016-01-01
In this work, we systematically investigate the favored $\\alpha$-decay half-lives and $\\alpha$ preformation probabilities of both odd-$A$ and doubly-odd nuclei related to ground and isomeric states around the doubly magic cores at $Z=82$, $N=82$ and at $Z=82$, $N=126$, respectively, within a two-potential approach from the view of the valence nucleon (or hole). The results show that the $\\alpha$ preformation probability is linear related to $N_\\text{p}N_\\text{n}$ or $N_\\text{p}N_\\text{n}I$, where $N_\\text{p}$, $N_\\text{n}$, and $I$ are the number of valence protons (or holes), the number of valence neutrons (or holes), and the isospin of the parent nucleus, respectively. Fitting the $\\alpha$ preformation probabilities data extracted from the differences between experimental data and calculated half-lives without a shell correction, we give two analytic formulas of the $\\alpha$ preformation probabilities and the values of corresponding parameters. Using those formulas and the parameters, we calculate the $\\alp...
Anghel, Claudia Ioana, E-mail: claudia.anghel@theory.nipne.ro [Department of Theoretical Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele, P.O.Box MG-6, RO-077125 (Romania); University of Bucharest, Faculty of Physics, RO-077125 Bucharest - Magurele (Romania); Silisteanu, Andrei Octavian [Radiopharmaceutical Research Center, Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele, P.O.Box MG-6, RO-077125 (Romania)
2015-12-07
The most important decay modes for heavy and superheavy nuclei are their α-decay and spontaneous fission. This work investigates the evolution and the competition of these decay modes in long isotopic sequences. The partial half-lives are given by minimal sets of parameters extracted from the fit of experimental data and theoretical results. A summary of the experimental and calculated α-decay and spontaneous fission half-lives of the isotopes of elements Rf, Db, and Sg is presented. Some half-life extrapolations for nuclides not yet known are also obtained.
The most important decay modes for heavy and superheavy nuclei are their α-decay and spontaneous fission. This work investigates the evolution and the competition of these decay modes in long isotopic sequences. The partial half-lives are given by minimal sets of parameters extracted from the fit of experimental data and theoretical results. A summary of the experimental and calculated α-decay and spontaneous fission half-lives of the isotopes of elements Rf, Db, and Sg is presented. Some half-life extrapolations for nuclides not yet known are also obtained
Gronau, Michael
2016-01-01
CP-violating asymmetries in $B \\to \\pi \\pi$ and $B \\to \\rho \\rho$ decays can help specify the weak phase $\\phi_2 = \\alpha$ of the Cabibbo-Kobayashi-% Maskawa (CKM) matrix. We discuss the impact of improved measurements of these processes such as will be available in the near future, finding special value in better measurement of the time-dependent CP violation parameter $S_{00}$ in $B^0 \\to \\pi^0 \\pi^0$ and $B^0 \\to \\rho^0 \\rho^0$. Reducing the errors on $B \\to \\rho \\rho$ measurements by a factor of two can potentially lead to an error in $\\phi_2 = \\alpha$ just above $2^\\circ$, at which level isospin-breaking corrections must be considered.
Alpha Anisotropy Studies of Near-Spherical and Deformed Nuclei
Van Duppen, P
2002-01-01
% IS329 \\\\ \\\\ Although it was the first decay mode to be discovered, the process of $\\alpha$-particle emission is still poorly understood. A few years ago the first systematic study of anisotropic $\\alpha$-decay triggered renewed theoretical interest. Nevertheless, today the theories are still not adequate enough and more experimental data are urgently needed. We therefore measure the $\\alpha$-anisotropies of the favoured transitions of a number of near-spherical Rn and At isotopes, and of deformed nuclei near A=220. As the different models yield contradictory predictions for the transitions that are investigated, the measurements will allow to discern on their validity. They will at the same time provide the necessary basis for further theoretical developments.
Alpha-decays to members of ground-state rotational band of heavy even-even nuclei
We apply a simple barrier penetration approach to calculate α-decay branching ratios to members of ground-state rotational band of heavy even-even nuclei. The influence of α-decay energy, the angular momentum of α-particle, and the excitation probability of the daughter nucleus is taken into account in our calculations. The theoretical branching ratios of α-transitions are found to agree with the available experimental data well. (author)
Ledoux, R.J.; Ordonez, C.E.; Bechara, M.J.; Al-Juwair, H.A.; Lavelle, G.; Cosman, E.R.
1984-09-01
Excitation functions of the /sup 12/C(/sup 12/C, ..cap alpha..)/sup 20/Ne reaction were measured at Theta/sub lab/ = 7.5/sup 0/ between E/sub c.m./ = 14-40 MeV and angular distributions were measured from E/sub c.m./ = 17.8 to 20.6 MeV. Summed yields reveal prominent intermediate structure resonances over the entire range which correlate well to resonances previously observed in elastic data. The resonances show enhanced decays to excited rotational bands in /sup 20/Ne with reduced widths comparable to those for the elastic channel and an order of magnitude greater than those for the /sup 20/Ne ground state band. A discussion is given of the resonances as shape-isomeric states in a shell model secondary minimum in /sup 24/Mg, and of the selective alpha decay as being transitions to states of related configuration in /sup 20/Ne.
Ledoux, R.J.; Ordoez, C.E.; Bechara, M.J.; Al-Juwair, H.A.; Lavelle, G.; Cosman, E.R.
1984-09-01
Excitation functions of the /sup 12/C(/sup 12/C,..cap alpha..) /sup 20/Ne reaction were measured at theta/sub lab/ = 7.5/sup 0/ between E/sub c.m./ = 14--40 MeV and angular distributions were measured from E/sub c.m./ = 17.8 to 20.6 MeV. Summed yields reveal prominent intermediate structure resonances over the entire range which correlate well to resonances previously observed in elastic data. The resonances show enhanced decays to excited rotational bands in /sup 20/Ne with reduced widths comparable to those for the elastic channel and an order of magnitude greater than those for the /sup 20/Ne ground state band. A discussion is given of the resonances as shape-isomeric states in a shell model secondary minimum in /sup 24/Mg, and of the selective alpha decay as being transitions to states of related configuration in /sup 20/Ne.
Krueger, Felix; Wilsenach, Heinrich; Zuber, Kai [IKTP TU-Dresden, Dresden (Germany)
2014-07-01
Alpha decays from long living isotopes are one of the limiting backgrounds for experiments searching for rare decays with stringent background constrains, such as neutrinoless double beta decay experiments. It is thus very important to accurately measure the half-lives of these decays, in order to properly model their background contribution. Therefore, it is important to be able to measure half-lives from alpha decays of the order of 1 x 10{sup 15} yr. A measurement of such a long lived decay imposes, however, a series of challenges, where the correct discrimination between background and true signal is critical. There is also a more general interest in such long living half-life measurements, as their value depends crucially on the underlying nuclear model. This work proposes a setup to measure long lived alpha decays, based on the design of the Frisch-Grid ionisation chamber. It is shown that the proposed design provides a good separation of signal and background events. It is also demonstrated that, with pulse shape analysis, it is possible to constrain the source position of the decay, further improving the quality of the data. A discussion of the characterisation of the detector is also presented as well as some results obtained with calibration sources.
Alpha decays from long living isotopes are one of the limiting backgrounds for experiments searching for rare decays with stringent background constrains, such as neutrinoless double beta decay experiments. It is thus very important to accurately measure the half-lives of these decays, in order to properly model their background contribution. Therefore, it is important to be able to measure half-lives from alpha decays of the order of 1 x 1015 yr. A measurement of such a long lived decay imposes, however, a series of challenges, where the correct discrimination between background and true signal is critical. There is also a more general interest in such long living half-life measurements, as their value depends crucially on the underlying nuclear model. This work proposes a setup to measure long lived alpha decays, based on the design of the Frisch-Grid ionisation chamber. It is shown that the proposed design provides a good separation of signal and background events. It is also demonstrated that, with pulse shape analysis, it is possible to constrain the source position of the decay, further improving the quality of the data. A discussion of the characterisation of the detector is also presented as well as some results obtained with calibration sources.
Study of alpha decay chains of superheavy nuclei and magic number beyond Z = 82 and N = 126
We study various α-decay chains on the basis of the preformed cluster decay model. Our work targets the superheavy elements, which are expected to show extra stability at shell closure. Our computations identify the following combinations of proton and neutron numbers as the most stable nuclei: Z=112, N=161,163; Z=114, N=171,178,179; and Z=124, N=194. We also investigate the alternative of heavy cluster emissions in the decay chain of 301120, instead of α decay. Our study of cluster radioactivity shows that the half-life for 10Be decay in 289114 is larger, indicating enhanced stability at Z=114, N=175. Similar calculations concerning the emission of 14C and 34Si from 301120 find the more stable combinations Z=114, N=173, and Z=106, N=161, respectively. From the same parent, 301120, the emission of a 49−51Ca cluster yielding a Z=100, N=152 daughter is the most probable. (author)
Zircon and apatite form as actinide host phases in several high-level waste forms and have been proposed as host phases for the disposition of excess weapons-grade Pu and other actinides. Additionally, closely-related structure types appear as actinide-bearing phases among the corrosion products of spent nuclear fuel and high-level waste glasses. Self-radiation damage from α-decay of the incorporated Pu or other actinides can affect the durability and performance of these actinide-bearing phases. For both zircon and apatite, these effects can be modeled as functions of storage time and repository temperature and validated by comparison with data from natural occurrences. Natural zircons and apatites, with ages up to 4 billion years, provide abundant evidence for their long-term durability because of their wide spread use in geochronology and fission-track dating. Detailed studies of natural zircons and apatites, 238Pu-containing zircon, a 244Cm-containing silicate apatite, and ion-irradiated zircon, natural apatite and synthetic silicate apatites provide a unique basis for the analysis of α-decay effects over broad time scales. Models for α-decay effects in zircon and apatite are developed that show α-decay of Pu and other actinides will lead to a crystalline-to-amorphous transformation in zircon, but not in apatite, under conditions typical of a repository, such as the Yucca Mountain site. (orig.)
A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO2(NO3)2 6H2O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author)
The gamma rays and conversion electrons emitted following neutron capture in a 237Np target have been measured by use of the GAMS and BILL spectrometers at Grenoble. Gamma ray and alpha particle measurements of /sup 242m/Am alpha decay (Ge(Li)γ singles, γ-γ coincidences, α singles) have been made at Livermore. The data from these measurements have been combined with earlier measurements (Ionescu 1979, Asaro 1964) to produce a more detailed level scheme for 238Np. Approximately 36 levels have been identified from all of the experimental evidence. The experimentally-observed bandhead energies can be compared with predicted values derived from a simple linear addition of excitation energies observed in neighboring odd-mass nuclei. Values for the Gallagher-Moszkowski splitting of each configurational pair were obtained from theoretical calculations (Piepenbring 1978). We have assigned configurations to ten rotational bands whose bandhead energies range from 0 to 342 keV and which represent all but one of the configurations predicted to occur below 385 keV
d'Enterria, David
2016-01-01
The current world-average of the strong coupling at the Z pole mass, $\\alpha_s(m^2_{Z}) = 0.1181 \\pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\\gamma$-p collisions; and photon F$_2$ structure function in $\\gamma\\,\\gamma$ collisions. These 14 $\\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.
Bouncing Anisotropic Universes with Varying Constants
Barrow, John D
2013-01-01
We examine the evolution of a closed, homogeneous and anisotropic cosmology subject to a variation of the fine structure 'constant', \\alpha, within the context of the theory introduced by Bekenstein, Sandvik, Barrow and Magueijo, which generalises Maxwell's equations and general relativity. The variation of \\alpha permits an effective ghost scalar field, whose negative energy density becomes dominant at small length scales, leading to a bouncing cosmology. A thermodynamically motivated coupling which describes energy exchange between the effective ghost field and the radiation field leads to an expanding, isotropizing sequence of bounces. In the absence of entropy production we also find solutions with stable anisotropic oscillations around a static universe.
Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bolnet, Nayanka Myriam; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutouil, Sara; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Gareth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bundock, Aaron Colin; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Charfeddine, Driss; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiefari, Giovanni; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christidi, Ilektra-Athanasia; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocio, Alessandra; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Connell, Simon Henry; Connelly, Ian; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Crispin Ortuzar, Mireia; Cristinziani, Markus; Crosetti, Giovanni; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Daniells, Andrew Christopher; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Darmora, Smita; Dassoulas, James; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lorenzi, Francesco; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; do Vale, Maria Aline Barros; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobos, Daniel; Dobson, Ellie; Doglioni, Caterina; Doherty, Tom; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dova, Maria-Teresa; Doyle, Tony; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Dwuznik, Michal; Dyndal, Mateusz; Ebke, Johannes; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Engelmann, Roderich; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Fernandez Perez, Sonia; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Julia; Fisher, Matthew; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flechl, Martin; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Florez Bustos, Andres Carlos; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gandrajula, Reddy Pratap; Gao, Jun; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkialas, Ioannis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Glonti, George; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goeringer, Christian; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Grebenyuk, Oleg; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Groth-Jensen, Jacob; Grout, Zara Jane; Grybel, Kai; Guan, Liang; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guicheney, Christophe; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Gunther, Jaroslav; Guo, Jun; Gupta, Shaun; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guttman, Nir; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageboeck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Hall, David; Halladjian, Garabed; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Heisterkamp, Simon; Hejbal, Jiri; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hofmann, Julia Isabell; Hohlfeld, Marc; Holmes, Tova Ray; Hong, Tae Min; Hooft van Huysduynen, Loek; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Ideal, Emma; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Inamaru, Yuki; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javůrek, Tomáš; Jeanty, Laura; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Erik; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Karnevskiy, Mikhail; Karpov, Sergey; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Keller, John; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; König, Sebastian; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kurumida, Rie; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laier, Heiko; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Le, Bao Tran; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire, Alexandra; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzen, Georg; Lenzi, Bruno; Leone, Robert; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Shu; Li, Xuefei; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Jonathan; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lungwitz, Matthias; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeno, Mayuko; Maeno, Tadashi; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marques, Carlos; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Homero; Martinez, Mario; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mättig, Peter; Mättig, Stefan; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Medinnis, Michael; Meehan, Samuel; Meera-Lebbai, Razzak; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Meric, Nicolas; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Moeller, Victoria; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Thibaut; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Nanava, Gizo; Narayan, Rohin; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Novakova, Jana; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pearce, James; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petteni, Michele; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pizio, Caterina; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Poddar, Sahill; Podlyski, Fabrice; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Przysiezniak, Helenka; Ptacek, Elizabeth; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qin, Gang; Quadt, Arnulf; Quarrie, David; Quayle, William; Quilty, Donnchadha; Qureshi, Anum; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Rangel-Smith, Camila; Rao, Kanury; Rauscher, Felix; Rave, Tobias Christian; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reinsch, Andreas; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Ridel, Melissa; Rieck, Patrick; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodrigues, Luis; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Matthew; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sacerdoti, Sabrina; Saddique, Asif; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Savard, Pierre; Savu, Dan Octavian; Sawyer, Craig; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaelicke, Andreas; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Christopher; Schmitt, Sebastian; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scott, Bill; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellers, Graham; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Seuster, Rolf; Severini, Horst; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherwood, Peter; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snow, Joel; Snyder, Scott; Sobie, Randall; Socher, Felix; Sodomka, Jaromir; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopko, Vit; Sopko, Bruno; Sorin, Veronica; Sosebee, Mark; Soualah, Rachik; Soueid, Paul; Soukharev, Andrey; South, David; Spagnolo, Stefania; Spanò, Francesco; Spearman, William Robert; Spighi, Roberto; Spigo, Giancarlo; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steele, Genevieve; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoerig, Kathrin; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Tran, Huong Lan; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Virzi, Joseph; Vitells, Ofer; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Wolfgang; Wagner, Peter; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chao; Wang, Chiho; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Xiaoxiao; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wittig, Tobias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wright, Michael; Wu, Mengqing; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Un-Ki; Yang, Yi; Yanush, Serguei; Yao, Liwen; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yen, Andy L; Yildirim, Eda; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Lei; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Lei; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zitoun, Robert; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zutshi, Vishnu; Zwalinski, Lukasz
2014-01-01
A measurement of the parity-violating decay asymmetry parameter, $\\alpha_b$, and the helicity amplitudes for the decay $\\Lambda_b^0\\to J/\\psi(\\mu^+\\mu^-) \\Lambda^0 (p\\pi^-)$ is reported. The analysis is based on 1400 $\\Lambda_b^0$ and $\\bar{\\Lambda}_b^0$ baryons selected in $4.6~\\rm{fb}^{-1}$ of proton--proton collision data with a center-of-mass energy of 7 TeV recorded by the ATLAS experiment at the LHC. By combining the $\\Lambda_b^0$ and $\\bar{\\Lambda}_b^0$ samples under the assumption of $CP$ conservation, the value of $\\alpha_b$ is measured to be $0.30\\pm0.16 ({\\rm stat})\\pm 0.06 ({\\rm syst})$. This measurement provides a test of theoretical models based on perturbative QCD or heavy-quark effective theory.
Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
2009-10-30
We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K{sub 1}(1270) or K{sub 1}(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation. We measure the branching fractions {Beta}(B{sup 0} {yields} K{sub 1}(1270){sup +}{pi}{sup -} + K{sub 1}(1400){sup +}{pi}{sup -}) = 3.1{sub 0.7}{sup +0.8} x 10{sup -5} and {Beta}(B{sup +} {yields} K{sub 1}(1270){sup 0}{pi}{sup +} + K{sub 1}(1400){sup 0}{pi}{sup +}) = 2.9{sub -1.7}{sup +2.9} x 10{sup -5} (< 8.2 x 10{sup -5} at 90% confidence level), where the errors are statistical and systematic combined. The B{sup 0} decay mode is observed with a significance of 7.5{sigma}, while a significance of 3.2{sigma} is obtained for the B{sup +} decay mode. Based on these results, we estimate the weak phase {alpha} = (79 {+-} 7 {+-} 11){sup o} from the time dependent CP asymmetries in B{sup 0} {yields} a{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decays.
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 89, č. 9 (2014), "092009-1"-"092009-12". ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : J/psi(3100) * leptonic decay * ATLAS * CERN LHC Coll * Heavy Quark Effective Theory * Lambda/b0 * hadronic decay Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014
Crossing Statistics of Anisotropic Stochastic Surface
Nezhadhaghighi, M Ghasemi; Yasseri, T; Allaei, S M Vaez
2015-01-01
We use crossing statistics and its generalization to determine the anisotropic direction imposed on a stochastic fields in $(2+1)$Dimension. This approach enables us to examine not only the rotational invariance of morphology but also we can determine the Gaussianity of underlying stochastic field in various dimensions. Theoretical prediction of up-crossing statistics (crossing with positive slope at a given threshold $\\alpha$ of height fluctuation), $\
Q-factor and absorption enhancement for plasmonic anisotropic nanoparticles
Liu, Wei; Miroshnichenko, Andrey E
2016-01-01
We investigate the scattering and absorption properties of anisotropic metal-dielectric core-shell nanoparticles. It is revealed that the radially anisotropic dielectric layer can accelerate the evanescent decay of the localized resonant surface modes, leading to Q-factor and absorption rate enhancement. Moreover, the absorption cross section can be maximized to reach the single resonance absorption limit. We further show that such artificial anisotropic cladding materials can be realized by isotropic layered structures, which may inspire many applications based on scattering and absorption of plasmonic nanoparticles.
Gonzalez, J.; Gaeta, R.; Vano, E.; Los Arcos, J. M.
1978-07-01
The excited levels in 233{sup P}a following the 237{sup N}p alpha decay have been studied, by performing different experiences to complete available data and supply new information. Thus, two direct alpha spectrum measurement, one alpha-gamma bidimensional coincidence experiment, three gamma-gamma and gamma-X ray coincidences and some other measurements of the gamma spectrum, direct and coincident with alpha-particles have been made. These last experiences have allowed to obviate usual radiochemical separation methods, the 233{sup P}a radioactive descendent interferences being eliminated by means of the coincidence technic. As a result, a primary decay scheme has been elaborated, including 15 new gamma transitions and two new levels, not observed in the most recent works. (Author) 60 refs.
Anisotropic Stars II Stability
Dev, K; Dev, Krsna; Gleiser, Marcelo
2003-01-01
We investigate the stability of self-gravitating spherically symmetric anisotropic spheres under radial perturbations. We consider both the Newtonian and the full general-relativistic perturbation treatment. In the general-relativistic case, we extend the variational formalism for spheres with isotropic pressure developed by Chandrasekhar. We find that, in general, when the tangential pressure is greater than the radial pressure, the stability of the anisotropic sphere is enhanced when compared to isotropic configurations. In particular, anisotropic spheres are found to be stable for smaller values of the adiabatic index $\\gamma$.
Shnoll, S. E.; Rubinshtejn, I. A.; Zenchenko, K. I.; Shlekhtarev, V. A.; Kaminsky, A. V.; Konradov, A. A.; Udaltsova, N. V.
2005-01-01
As shown in our previous experiments fine structure of histograms of alpha-activity measurements serve as a sensitive tool for investigation of cosmo-physical influences. Particularly, the histograms structure is changed with the period equal to sidereal (1436 min) and solar (1440) day. It is similar with the high probability in different geographic points at the same local (longitude) time. More recently investigations were carried out with collimators, cutting out separate flows of total al...
Puchalski, Mariusz; Czarnecki, Andrzej; Karshenboim, Savely G.
2007-01-01
We present a precise theoretical prediction for the decay width of the bound state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-) = 2.087 085(12)/ns. We include O(alpha^2) effects of hard virtual photons as well as soft corrections to the wave function and the decay amplitude. An outcome of a large-scale variational calculation, this is the first result for second-order corrections to a decay of a three-particle bound state. It will be tested experimentally in the n...
Sile Nic Chormaic; Slevin, J. (Saint Patrick' s Coll., Maynooth (Ireland)); Chwirot, S. (Uniwersytet Mikolaja Kopernika, Torun (Poland). Inst. Fizyki)
1993-01-14
New coincidence measurements are reported for the circular polarization of Lyman-[alpha] radiation resulting from the decay of 2[sup 2]P[sub j] states excited by electron impact at an incident energy of 54.4 eV in a range of scattering angles from 5[sup o] [<=] [theta][sub e] [<=] 40[sup o]. The data were obtained using a recently developed efficient polarization analyser for this spectral line and the statistical significance of the data is much better than for previously reported measurements. The data are analysed to yield values for the coherence parameter P[sup +] and show that spin exchange interactions play a significant, if unexpected, role in the dynamic range investigated. (author).
Level structure of 217Rn and 221Ra investigated in the alpha-decay 225Th → 221Ra → 217Rn
The nuclei 221Ra and 217Rn have been investigated in the α-decay chain 225Th → 221Ra → 217Rn through γ-ray and conversion-electron studies. The short-lived 225Th nuclei (T1/2=8 min) were produced in the 226Ra(α, 5n) reaction, and γ-rays and conversion electrons were measured - between the irradiation periods - in coincidence with α-particles. In 221Ra the five lowest levels are interpreted as members of a K=5/2 parity-doublet with ΔEπ=104 keV. These levels, as well as a higher-lying Kπ=3/2+ band, are consistent with an octupole deformation of 221Ra, as expected from theoretical considerations. In 217Rn only three excited levels are observed, with a favoured α-decay to a 5/2+ excited level thus establishing positive parity for the ground state of 221Ra. (orig.)
Search for CP violation in hyperon decays.
Zyla, Piotr; Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K.; Choong, W.S.; Gidal, G.; Fu, Y.; Gu, P.; Jones, T.D.; Luk, K.B.; Turko, B.; James, C.; Volk, J.; Felix, J.; Burnstein, R.A.; Chakrovorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; Solomey, N.; Torun, Y.; White, C.G.; White, S.L.; Leros, N.; Perroud, J.P.; Gustafson, H.R.; Longo, M.J.; Lopez, F.; Park H.K.; Clark, K.; Jenkins, M.; Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Lu, L.; Nelson, K.S.
2002-10-25
Direct CP violation in nonleptonic hyperon decays can be established by comparing the decays of hyperons and anti-hyperons. For {Xi} decay to {Lambda} {pi} followed by {Lambda} to p{pi}, the proton distribution in the rest frame of Lambda is governed by the product of the decay parameters {alpha}{sub {Xi}} {alpha}{sub {Lambda}}. The asymmetry A{sub {Xi}{Lambda}}, proportional to the difference of {alpha}{sub {Xi}}{alpha}{sub {Lambda}} of the hyperon and anti-hyperon decays, vanishes if CP is conserved. We report on an analysis of a fraction of 1997 and 1999 data collected by the Hyper CP (E871) collaboration during the fixed-target runs at Fermilab. The preliminary measurement of the asymmetry is {Alpha}{sub {Xi}{Lambda}} = [-7 {+-} 12(stat) {+-} 6.2(sys)] x 10{sup -4}, an order of magnitude better than the present limit.
Filin E. Y.
2015-07-01
Full Text Available It was discovered many years ago that histograms constructed from the results of mea- surements of various natural processes are not random. The histogram shape was demonstrated to be determined by the diurnal rotation and circumsolar movement of the Earth and to be independent of the nature of the process considered [1-17]. The results of those works change our basic views about stochasticity of natural processes. When the time series of physical measurements, which are traditionally considered stochastic, are transformed into the series of histograms constructed for an optimally small num- ber of the results (i.e., optimally short segment of the time series, one can see regular changes in the histogram shape. The paper illustrates the main manifestations of this phenomenon by comparing the results of 90 Sr -radioactivity and 239 Pu -decay mea- surements, with the distance between the laboratories in which the data were collected being about 3000 km.
Conformal Ricci and Matter Collineations for Anisotropic Fluid
Sharif, M
2007-01-01
We study the consequences of timelike and spaccelike conformal Ricci and conformal matter collineations for anisotropic fluid in the context of General Relativity. Necessary and sufficient conditions are derived for a spacetime with anisotropic fluid to admit conformal Ricci and conformal matter collineations parallel to u^a and x^a. These conditions for timelike and spacelike conformal Ricci and conformal matter collineations for anisotropic fluid reduce to the conditions of perfect fluid when the heat flux and the traceless anisotropic stress tensor vanish. Further, for $\\alpha=0$ (the conformal factor), we recover the earlier results of Ricci collineations and matter collineations in each case of timelike and spacelike conformal Ricci collineations and conformal matter collineations for the perfect fluid. Thus our results give the generalization of the results already available in the literature. It is worth noticing that the conditions of conformal matter collineations can be derived from the conditions o...
Zeng, Dai-Min; Wang, Sheng-Quan; Wu, Xing-Gang; Shen, Jian-Ming
2016-07-01
We study the Higgs-boson decay width {{Γ }}(H\\to {gg}) up to {α }s5 order under the minimal momentum space subtraction (mMOM) scheme. A major uncertainty of a finite-order perturbative quantum chromodymaics (pQCD) prediction is the perceived ambiguity in setting the renormalization scale. In the present paper, to achieve a precise pQCD prediction without renormalization scale uncertainty, we adopt the principle of maximum conformality (PMC) to set the renormalization scale of the process. The PMC has a solid theoretical foundation, which is based on renormalization group invariance and utilizes the renormalization group equation to fix the renormalization scale of the process. The key point of the application of the PMC is how to correctly set the {β i } terms of the process to achieve the correct α s -running behavior at each perturbative order. It is found that the ambiguities in dealing with the {β i } terms of the decay width {{Γ }}(H\\to {gg}) under the \\bar{{{MS}}} scheme can be avoided by using the physical mMOM scheme. For this purpose, for the first time we provide the PMC scale-setting formulas within the mMOM scheme up to a four-loop level. By using the PMC, it is found that a more reliable pQCD prediction on {{Γ }}(H\\to {gg}) can indeed be achieved under the mMOM scheme. As a byproduct, the convergence of the resultant pQCD series has been greatly improved due to the elimination of renormalon terms. By taking the newly measured Higgs mass, M H = 125.09 ± 0.21 ± 0.11 GeV, our PMC prediction of the decay width is, {{Γ }}(H\\to {gg}){| }{{mMOM,}{{PMC}}}=339.3+/- {1.7}-2.4+3.7 keV, in which the first error is from the Higgs mass uncertainty and the second error is the residual renormalization scale dependence by varying the initial renormalization scale {μ }r\\in [{M}H/2,4{M}H].
Weibel instability driven by spatially anisotropic density structures
Tomita, Sara
2016-01-01
Observations of afterglows of gamma-ray bursts suggest (GRBs) that post-shock magnetic fields are strongly amplified to about 100 times the shock-compressed value. The Weibel instability appears to play an important role in generating of the magnetic field. However, recent simulations of collisionless shocks in homogeneous plasmas show that the magnetic field generated by the Weibel instability rapidly decays. There must be some density fluctuations in interstellar and circumstellar media. The density fluctuations are anisotropically compressed in the downstream region of relativistic shocks. In this paper, we study the Weibel instability in electron--positron plasmas with the spatially anisotropic density distributions by means of two-dimensional particle-in-cell simulations. We find that large magnetic fields are maintained for a longer time by the Weibel instability driven by the spatially anisotropic density structure. Particles anisotropically escape from the high density region, so that the temperature ...
Anisotropic Long-Range Spin Systems
Defenu, Nicolò; Ruffo, Stefano
2016-01-01
We consider anisotropic long-range interacting spin systems in $d$ dimensions. The interaction between the spins decays with the distance as a power law with different exponents in different directions: we consider an exponent $d_{1}+\\sigma_1$ in $d_1$ directions and another exponent $d_{2}+\\sigma_2$ in the remaining $d_2\\equiv d-d_1$ ones. We introduce a low energy effective action with non analytic power of the momenta. As a function of the two exponents $\\sigma_1$ and $\\sigma_2$ we show the system to have three different regimes, two where it is actually anisotropic and one where the isotropy is finally restored. We determine the phase diagram and provide estimates of the critical exponents as a function of the parameters of the system, in particular considering the case of one of the two $\\sigma$'s fixed and the other varying. A discussion of the physical relevance of our results is also presented.
Averaging anisotropic cosmologies
We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of anisotropic pressure-free models. Adopting the Buchert scheme, we recast the averaged scalar equations in Bianchi-type form and close the standard system by introducing a propagation formula for the average shear magnitude. We then investigate the evolution of anisotropic average vacuum models and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. The presence of nonzero average shear in our equations also allows us to examine the constraints that a phase of backreaction-driven accelerated expansion might put on the anisotropy of the averaged domain. We close by assessing the status of these and other attempts to define and calculate 'average' spacetime behaviour in general relativity
Anisotropic Metamaterial Optical Fibers
Pratap, Dheeraj; Pollock, Justin G; Iyer, Ashwin K
2014-01-01
Internal physical structure can drastically modify the properties of waveguides: photonic crystal fibers are able to confine light inside a hollow air core by Bragg scattering from a periodic array of holes, while metamaterial loaded waveguides for microwaves can support propagation at frequencies well below cutoff. Anisotropic metamaterials assembled into cylindrically symmetric geometries constitute light-guiding structures that support new kinds of exotic modes. A microtube of anodized nanoporous alumina, with nanopores radially emanating from the inner wall to the outer surface, is a manifestation of such an anisotropic metamaterial optical fiber. The nanopores, when filled with a plasmonic metal such as silver or gold, greatly increase the electromagnetic anisotropy. The modal solutions in anisotropic circular waveguides can be uncommon Bessel functions with imaginary orders.
Hwu, Chyanbin
2010-01-01
As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a
Pérez-Nadal, Guillem
2016-01-01
We consider a non-relativistic free scalar field theory with a type of anisotropic scale invariance in which the number of coordinates "scaling like time" is generically greater than one. We propose the Cartesian product of two curved spaces, with the metric of each space parameterized by the other space, as a notion of curved background to which the theory can be extended. We study this type of geometries, and find a family of extensions of the theory to curved backgrounds in which the anisotropic scale invariance is promoted to a local, Weyl-type symmetry.
On the Newtonian anisotropic configurations
Shojai, F. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), Foundations of Physics Group, School of Physics, Tehran (Iran, Islamic Republic of); Fazel, M.R.; Stepanian, A. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of); Kohandel, M. [Alzahra University, Department of Sciences, Tehran (Iran, Islamic Republic of)
2015-06-15
In this paper we are concerned with the effects of an anisotropic pressure on the boundary conditions of the anisotropic Lane-Emden equation and the homology theorem. Some new exact solutions of this equation are derived. Then some of the theorems governing the Newtonian perfect fluid star are extended, taking the anisotropic pressure into account. (orig.)
B B Bhowmik; A Rajput
2004-06-01
Anisotropic Bianchi Type-I cosmological models have been studied on the basis of Lyra's geometry. Two types of models, one with constant deceleration parameter and the other with variable deceleration parameter have been derived by considering a time-dependent displacement field.
Anisotropic Ambient Volume Shading.
Ament, Marco; Dachsbacher, Carsten
2016-01-01
We present a novel method to compute anisotropic shading for direct volume rendering to improve the perception of the orientation and shape of surface-like structures. We determine the scale-aware anisotropy of a shading point by analyzing its ambient region. We sample adjacent points with similar scalar values to perform a principal component analysis by computing the eigenvectors and eigenvalues of the covariance matrix. In particular, we estimate the tangent directions, which serve as the tangent frame for anisotropic bidirectional reflectance distribution functions. Moreover, we exploit the ratio of the eigenvalues to measure the magnitude of the anisotropy at each shading point. Altogether, this allows us to model a data-driven, smooth transition from isotropic to strongly anisotropic volume shading. In this way, the shape of volumetric features can be enhanced significantly by aligning specular highlights along the principal direction of anisotropy. Our algorithm is independent of the transfer function, which allows us to compute all shading parameters once and store them with the data set. We integrated our method in a GPU-based volume renderer, which offers interactive control of the transfer function, light source positions, and viewpoint. Our results demonstrate the benefit of anisotropic shading for visualization to achieve data-driven local illumination for improved perception compared to isotropic shading. PMID:26529745
Dynamics of Anisotropic Universes
Pérez, J
2006-01-01
We present a general study of the dynamical properties of Anisotropic Bianchi Universes in the context of Einstein General Relativity. Integrability results using Kovalevskaya exponents are reported and connected to general knowledge about Bianchi dynamics. Finally, dynamics toward singularity in Bianchi type VIII and IX universes are showed to be equivalent in some precise sence.
$Gamma(H\\to b\\bar{b})$ to order $\\alpha\\alpha_s$
Mihaila, Luminita; Steinhauser, Matthias
2015-01-01
We compute the decay rate of the Standard Model Higgs boson to bottom quarks to order $\\alpha\\alpha_s$. We apply the optical theorem and calculate the imaginary part of three-loop corrections to the Higgs boson propagator using asymptotic expansions in appropriately chosen mass ratios. The corrections of order $\\alpha\\alpha_s$ are of the same order of magnitude as the ${\\cal O}(\\alpha_s^3)$ QCD corrections but have the opposite sign.
Stracka, Simone; /Milan U. /SLAC
2011-02-07
In the Standard Model, CP violation in weak interactions involving quarks is parameterized by an irreducible complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing-matrix. The precise determination of the CKM elements is a necessary ingredient for a stringent test of the Standard Model predictions, and is a crucial input for reducing the theoretical error in many New Physics searches with flavor, e.g., in the kaon sector. The unitarity of the CKM matrix is typically expressed as a triangle relationship among its parameters, where the area of the so-called Unitarity Triangle visually depicts the amount of asymmetry between the decays of B particles and their antimatter counterparts. In the past few years, the BABAR and Belle experiments have been able to measure all three angles of the triangle from CP asymmetry measurements. The first asymmetry measurements in B particle decays, about ten years ago, allowed to determine {beta}, which is now known to better than 5% precision. The angles {alpha} and {gamma}, measured in much rarer processes, required several years of data taking before analyses could yield reliable answers. A remarkable feature is that the direct measurement of the angles of the Unitarity Triangle generates an area that is consistent with the area predicted by measurement of the sides. In this thesis we have presented the branching fraction measurements of charged and neutral B meson decays to K{sub 1}(1270){pi} and K{sub 1}(1400){pi}, obtained from a data sample of 454 million {Upsilon}(4S) {yields} B{bar B} events. This analysis is particularly challenging from the experimental side since the branching fractions involved are very low, at the level of 10{sup -6} - 10{sup -7}, and the signal is characterized by the simultaneous presence of two overlapping resonances, which exhibit sizeable interference effects. The combined K{sub 1}(1270){pi} and K{sub 1}(1400){pi} signal is therefore modeled with a K-matrix formalism, which accounts for
Recoil-alpha-fission and recoil-alpha-alpha-fission events observed in the reaction Ca-48 + Am-243
Forsberg, U; Andersson, L -L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Golubev, P; Gregorich, K E; Gross, C J; Herzberg, R -D; Hessberger, F P; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Sarmiento, L G; Schädel, M; Yakushev, A; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Dobaczewski, J; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nazarewicz, W; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Shi, Y; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N
2015-01-01
Products of the fusion-evaporation reaction Ca-48 + Am-243 were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum f\\"ur Schwerionenforschung. Amongst the detected thirty correlated alpha-decay chains associated with the production of element Z=115, two recoil-alpha-fission and five recoil-alpha-alpha-fission events were observed. The latter are similar to four such events reported from experiments performed at the Dubna gas-filled separator. Contrary to their interpretation, we propose an alternative view, namely to assign eight of these eleven decay chains of recoil-alpha(-alpha)-fission type to start from the 3n-evaporation channel 115-288. The other three decay chains remain viable candidates for the 2n-evaporation channel 115-289.
Fractures in anisotropic media
Shao, Siyi
Rocks may be composed of layers and contain fracture sets that cause the hydraulic, mechanical and seismic properties of a rock to be anisotropic. Coexisting fractures and layers in rock give rise to competing mechanisms of anisotropy. For example: (1) at low fracture stiffness, apparent shear-wave anisotropy induced by matrix layering can be masked or enhanced by the presence of a fracture, depending on the fracture orientation with respect to layering, and (2) compressional-wave guided modes generated by parallel fractures can also mask the presence of matrix layerings for particular fracture orientations and fracture specific stiffness. This report focuses on two anisotropic sources that are widely encountered in rock engineering: fractures (mechanical discontinuity) and matrix layering (impedance discontinuity), by investigating: (1) matrix property characterization, i.e., to determine elastic constants in anisotropic solids, (2) interface wave behavior in single-fractured anisotropic media, (3) compressional wave guided modes in parallel-fractured anisotropic media (single fracture orientation) and (4) the elastic response of orthogonal fracture networks. Elastic constants of a medium are required to understand and quantify wave propagation in anisotropic media but are affected by fractures and matrix properties. Experimental observations and analytical analysis demonstrate that behaviors of both fracture interface waves and compressional-wave guided modes for fractures in anisotropic media, are affected by fracture specific stiffness (controlled by external stresses), signal frequency and relative orientation between layerings in the matrix and fractures. A fractured layered medium exhibits: (1) fracture-dominated anisotropy when the fractures are weakly coupled; (2) isotropic behavior when fractures delay waves that are usually fast in a layered medium; and (3) matrix-dominated anisotropy when the fractures are closed and no longer delay the signal. The
Anisotropic progressive photon mapping
Liu, XiaoDan; Zheng, ChangWen
2014-01-01
Progressive photon mapping solves the memory limitation problem of traditional photon mapping. It gives the correct radiance with a large passes, but it converges slowly. We propose an anisotropic progressive photon mapping method to generate high quality images with a few passes. During the rendering process, different from standard progressive photon mapping, we store the photons on the surfaces. At the end of each pass, an anisotropic method is employed to compute the radiance of each eye ray based on the stored photons. Before move to a new pass, the photons in the scene are cleared. The experiments show that our method generates better results than the standard progressive photon mapping in both numerical and visual qualities.
Molecular anisotropic magnetoresistance
Otte, Fabian; Heinze, Stefan; Mokrousov, Yuriy
2015-01-01
Using density functional theory calculations, we demonstrate that the effect of anisotropic magnetoresistance (AMR) can be enhanced by orders of magnitude with respect to conventional bulk ferromagnets in junctions containing molecules sandwiched between ferromagnetic leads. We study ballistic transport in metal-benzene complexes contacted by $3d$ transition-metal wires. We show that the gigantic AMR can arise from spin-orbit coupling effects in the leads, drastically enhanced by orbital-symm...
Extremely Anisotropic Scintillations
Walker, Mark; Bignall, Hayley
2008-01-01
A small number of quasars exhibit interstellar scintillation on time-scales less than an hour; their scintillation patterns are all known to be anisotropic. Here we consider a totally anisotropic model in which the scintillation pattern is effectively one-dimensional. For the persistent rapid scintillators J1819+3845 and PKS1257-326 we show that this model offers a good description of the two-station time-delay measurements and the annual cycle in the scintillation time-scale. Generalising the model to finite anisotropy yields a better match to the data but the improvement is not significant and the two additional parameters which are required to describe this model are not justified by the existing data. The extreme anisotropy we infer for the scintillation patterns must be attributed to the scattering medium rather than a highly elongated source. For J1819+3845 the totally anisotropic model predicts that the particular radio flux variations seen between mid July and late August should repeat between late Au...
Panayiotis Panayides
2013-01-01
Heavy reliance on Cronbach’s alpha has been standard practice in many validation studies. However, there seem to be two misconceptions about the interpretation of alpha. First, alpha is mistakenly considered as an indication of unidimensionality and second, that the higher the value of alpha the better. The aim of this study is to clarify these misconceptions with the use of real data from the educational setting. Results showed that high alpha values can be obtained in multidimensional scale...
The decay of 156Er has been investigated with the 160Dy(α, 8n) reaction at a alpha particle energy of 120 MeV. The gross excitation function of alpha particle reaction to 160Dy was examined at the 90, 100 and 110 MeV energy decreasing from 120 MeV with aluminum absorbers on the irradiation facility of I course. As a result of the excitation function, the threshold energy of 160Dy(α, 8n) reaction was estimated to about 100 MeV of alpha particles on laboratory system. Then, the irradiation energy of 110 MeV was chosen for the production of 156Er. The gamma rays and X rays spectra from 156Er were studied with 40 cc Ge(Li) detector and 0.5 cc pure Ge detector, and the half life was measured. (author)
Investigation of probable decays in rhenium isotopes
Making use of effective liquid drop model (ELDM), the feasibility of proton and alpha decays and various cluster decays is analysed theoretically. For different neutron-rich and neutron-deficient isotopes of Rhenium in the mass range 150 < A < 200, the half-lives of proton and alpha decays and probable cluster decays are calculated considering the barrier potential as the effective liquid drop one which is the sum of Coulomb, surface and centrifugal potentials. The calculated half-lives for proton decay from various Rhenium isotopes are then compared with the universal decay law (UDL) model to assess the efficiency of the present formalism. Geiger-Nuttal plots of the probable decays are analysed and their respective slopes and intercepts are evaluated
Background canceling surface alpha detector
A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs
Computer simulations of the anisotropic Josephson junction arrays
Using complementary methods, we numerically investigate the anisotropic Josephson junction arrays (AJJAs). For various anisotropic strengths (λ), the Monte Carlo simulation gives a precise measurement of specific heat, magnetization, and magnetic susceptibility; while the resistively shunted-junction dynamical simulation produces the current-voltage characteristics. The critical temperatures obtained from the two approaches are well consistent with each other. We find that, except for the anisotropic limit (λ=0), the quasi-long-range order is always established at a finite temperature. Further, the algebraically decaying spin-spin correlations in the low-temperature region are analyzed in detail. Finally, the full phase diagram of the AJJAs, which sheds some lights to the crossover of the XY model from one dimension to two, is constructed. These predictions are to be confronted with future experiments.
Computer simulations of the anisotropic Josephson junction arrays
Lv Jianping, E-mail: phys.lv@gmail.com [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Zhu Shujing [Department of Physics, Zhejiang University, Hangzhou 310027 (China)
2012-12-15
Using complementary methods, we numerically investigate the anisotropic Josephson junction arrays (AJJAs). For various anisotropic strengths ({lambda}), the Monte Carlo simulation gives a precise measurement of specific heat, magnetization, and magnetic susceptibility; while the resistively shunted-junction dynamical simulation produces the current-voltage characteristics. The critical temperatures obtained from the two approaches are well consistent with each other. We find that, except for the anisotropic limit ({lambda}=0), the quasi-long-range order is always established at a finite temperature. Further, the algebraically decaying spin-spin correlations in the low-temperature region are analyzed in detail. Finally, the full phase diagram of the AJJAs, which sheds some lights to the crossover of the XY model from one dimension to two, is constructed. These predictions are to be confronted with future experiments.
Shear-free anisotropic cosmological models in {f (R)} gravity
Abebe, Amare; Momeni, Davood; Myrzakulov, Ratbay
2016-04-01
We study a class of shear-free, homogeneous but anisotropic cosmological models with imperfect matter sources in the context of f( R) gravity. We show that the anisotropic stresses are related to the electric part of the Weyl tensor in such a way that they balance each other. We also show that within the class of orthogonal f( R) models, small perturbations of shear are damped, and that the electric part of the Weyl tensor and the anisotropic stress tensor decay with the expansion as well as the heat flux of the curvature fluid. Specializing in locally rotationally symmetric spacetimes in orthonormal frames, we examine the late-time behaviour of the de Sitter universe in f( R) gravity. For the Starobinsky model of f( R), we study the evolutionary behavior of the Universe by numerically integrating the Friedmann equation, where the initial conditions for the expansion, acceleration and jerk parameters are taken from observational data.
Quantum time scales in alpha tunneling
Kelkar, N G; Nowakowski, M
2008-01-01
The theoretical treatment of alpha decay by Gamow is revisited by investigating the quantum time scales in tunneling. The time spent by an alpha particle in front of the barrier and traversing it before escape is evaluated using microscopic alpha nucleus potentials. The half-life of a nucleus is shown to correspond to the time spent by the alpha knocking in front of the barrier. Calculations for medium and super heavy nuclei show that from a multitude of available tunneling time definitions, the transmission dwell time gives the bulk of the lifetime of the decaying state, in most cases.
Workshop on Precision Measurements of $\\alpha_s$
Bethke, Siegfried; /Munich, Max Planck Inst.; Hoang, Andre H.; /Vienna U.; Kluth, Stefan; /Munich, Max Planck Inst.; Schieck, Jochen; /Munich U.; Stewart, Iain W.; Aoki, S.; Beneke, M.; Bethke, S.; Blumlein, J.; Brambilla, N.; Brodsky, S.; /MIT, LNS
2011-10-01
These are the proceedings of the Workshop on Precision Measurements of {alpha}{sub s} held at the Max-Planck-Institute for Physics, Munich, February 9-11, 2011. The workshop explored in depth the determination of {alpha}{sub s}(m{sub Z}) in the {ovr MS} scheme from the key categories where high precision measurements are currently being made, including DIS and global PDF fits, {tau}-decays, electro-weak precision observables and Z-decays, event-shapes, and lattice QCD. These proceedings contain a short summary contribution from the speakers, as well as the lists of authors, conveners, participants, and talks.
Model anisotropic quantum Hall states
Qiu, R. -Z.; Haldane, F.D.M.; Wan, Xin; Yang, Kun; Yi, Su
2012-01-01
Model quantum Hall states including Laughlin, Moore-Read and Read-Rezayi states are generalized into appropriate anisotropic form. The generalized states are exact zero-energy eigenstates of corresponding anisotropic two- or multi-body Hamiltonians, and explicitly illustrate the existence of geometric degrees of in the fractional quantum Hall effect. These generalized model quantum Hall states can provide a good description of the quantum Hall system with anisotropic interactions. Some numeri...
On the Relativistic anisotropic configurations
Shojai, F; Stepanian, A
2016-01-01
In this paper we study anisotropic spherical polytropes within the framework of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov (TOV) equations, we explore the relativistic anisotropic Lane-Emden equations. We find how the anisotropic pressure affects the boundary conditions of these equations. Also we argue that the behaviour of physical quantities near the center of star changes in the presence of anisotropy. For constant density, a class of exact solution is derived with the aid of a new ansatz and its physical properties are discussed.
Relaxation of Anisotropic Glasses
Deubener, Joachim; Martin, Birgit; Wondraczek, Lothar; Yue, Yuanzheng
2004-01-01
Anisotropic glasses are obtained from uniaxial compressing and pulling of glass forming liquids above the transition temperature range. To freeze-in, at least partly the structural state of the flowing melt, cylindrical samples were subjected to a controlled cooling process under constant load...... differential scanning calorimetry (DSC) and dilatometry. The energy release and expansion-shrinkage behaviour of the glasses are investigated as a function of the applied deformation stress. Structural origins of the frozen-in birefringence induced by viscous flow are discussed and correlation between the...
Anisotropically Inflating Universes
Barrow, J D; Barrow, John D.; Hervik, Sigbjorn
2008-01-01
We show that in theories of gravity that add quadratic curvature invariants to the Einstein-Hilbert action there exist expanding vacuum cosmologies with positive cosmological constant which do not approach the de Sitter universe. Exact solutions are found which inflate anisotropically. This behaviour is driven by the Ricci curvature invariant and has no counterpart in the general relativistic limit. These examples show that the cosmic no-hair theorem does not hold in these higher-order extensions of general relativity and raises new questions about the ubiquity of inflation in the very early universe and the thermodynamics of gravitational fields.
Anisotropic Stars Exact Solutions
Dev, K; Dev, Krsna; Gleiser, Marcelo
2000-01-01
We study the effects of anisotropic pressure on the properties of spherically symmetric, gravitationally bound objects. We consider the full general relativistic treatment of this problem and obtain exact solutions for various form of equations of state connecting the radial and tangential pressures. It is shown that pressure anisotropy can have significant effects on the structure and properties of stellar objects. In particular, the maximum value of 2M/R can approach unity (2M/R < 8/9 for isotropic objects) and the surface redshift can be arbitrarily large.
Modes of decay in neutron-rich nuclei
Kumar, B; Singh, S K; Lahiri, C; Patra, S K
2016-01-01
We calculate the ground, first intrinsic excited states and density distribution for neutron-rich thorium and uranium isotopes, within the framework of relativistic mean field(RMF) approach using axially deformed basis. The total nucleon densities are calculated, from which the cluster-structures inside the parent nuclei are determined. The possible modes of decay, like {\\alpha}-decay and \\b{eta} -decay are analyzed. We find the neutron-rich isotopes are stable against {\\alpha}-decay, however they are very much unstable against \\b{eta} -decay. The life time of these nuclei predicted to be tens of second against \\b{eta} -decay.
Massless Fermions in anisotropic Bianchi type I spacetimes
Wollensak, Matthias
2016-01-01
The behavior of spin - 1/2 - particles in anisotropic Bianchi type I backgrounds is investigated utilizing the concept of differential forms and orthonormal frames. Specializing to the massless case and power law scale factors $\\alpha_j(t) = t^{q_j}$ of the metric where $q_1 = q_2 $, an analytical outcome for the time evolution operator in terms of Bessel functions is presented.
Optics of anisotropic nanostructures
Rokushima, Katsu; Antoš, Roman; Mistrík, Jan; Višňovský, Štefan; Yamaguchi, Tomuo
2006-07-01
The analytical formalism of Rokushima and Yamakita [J. Opt. Soc. Am. 73, 901-908 (1983)] treating the Fraunhofer diffraction in planar multilayered anisotropic gratings proved to be a useful introduction to new fundamental and practical situations encountered in laterally structured periodic (both isotropic and anisotropic) multilayer media. These are employed in the spectroscopic ellipsometry for modeling surface roughness and in-depth profiles, as well as in the design of various frequency-selective elements including photonic crystals. The subject forms the basis for the solution of inverse problems in scatterometry of periodic nanostructures including magnetic and magneto-optic recording media. It has no principal limitations as for the frequencies and period to radiation wavelength ratios and may include matter wave diffraction. The aim of the paper is to make this formalism easily accessible to a broader community of students and non-specialists. Many aspects of traditional electromagnetic optics are covered as special cases from a modern and more general point of view, e.g., plane wave propagation in isotropic media, reflection and refraction at interfaces, Fabry-Perot resonator, optics of thin films and multilayers, slab dielectric waveguides, crystal optics, acousto-, electro-, and magneto-optics, diffraction gratings, etc. The formalism is illustrated on a model simulating the diffraction on a ferromagnetic wire grating.
Anisotropic spheres in general relativity
A prescription originally conceived for perfect fluids is extended to the case of anisotropic pressures. The method is used to obtain exact analytical solutions of the Einstein equations for spherically symmetric selfgravitating distribution of anisotropic matter. The solutions are matched to the Schwarzschild exterior metric. (author). 15 refs
Turchikhin, Semen; The ATLAS collaboration
2016-01-01
Recent results on $\\Lambda^0_b$ baryon and $B_c^+$ meson decay studies from the ATLAS experiment at the LHC are presented. These include measurement of the parity-violating asymmetry parameter $\\alpha_b$ and the helicity amplitudes for the $\\Lambda^0_b\\to J/\\psi\\Lambda^0_b$ decay, first observation of the $\\Lambda^0_b\\to\\psi(2S)\\Lambda^0_b$ decay and measurement of its rate relative to the $\\Lambda^0_b\\to J/\\psi\\Lambda^0$ decay, and study of the $B_c^+\\to J/\\psi D_s^{(*)+}$ decay properties.
The 2009 Wolrd Average of $\\alpha_s (M_Z)$
Bethke, Siegfried
2009-01-01
Measurements of $\\alpha_s$, the coupling strength of the Strong Interaction between quarks and gluons, are summarised and an updated value of the world average of $\\alpha_s (M_Z)$ is derived. Building up on previous reviews, special emphasis is laid on the most recent determinations of $\\alpha_s$. These are obtained from $\\tau$-decays, from global fits of electroweak precision data and from measurements of the proton structure function $\\F_2$, which are based on perturbative QCD calculations up to $O(\\alpha_s^4)$; from hadronic event shapes and jet production in $\\epem$ annihilation, based on $O(\\alpha_s^3) $ QCD; from jet production in deep inelastic scattering and from $\\Upsilon$ decays, based on $O(\\alpha_s^2) $ QCD; and from heavy quarkonia based on unquenched QCD lattice calculations. Applying pragmatic methods to deal with possibly underestimated errors and/or unknown correlations, the world average value of $\\alpha_s (M_Z)$ results in $\\alpha_s (M_Z) = 0.1184 \\pm 0.0007$. The measured values of $\\alpha...
Averaging anisotropic cosmologies
Barrow, J D; Barrow, John D.; Tsagas, Christos G.
2006-01-01
We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of pressure-free Bianchi-type models. Adopting the Buchert averaging scheme, we identify the kinematic backreaction effects by focussing on spacetimes with zero or isotropic spatial curvature. This allows us to close the system of the standard scalar formulae with a propagation equation for the shear magnitude. We find no change in the already known conditions for accelerated expansion. The backreaction terms are expressed as algebraic relations between the mean-square fluctuations of the models' irreducible kinematical variables. Based on these we investigate the early evolution of averaged vacuum Bianchi type $I$ universes and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. We also discuss the possibility of accelerated expansion due to ...
Thermodynamics of anisotropic branes
Ávila, Daniel; Patiño, Leonardo; Trancanelli, Diego
2016-01-01
We study the thermodynamics of flavor D7-branes embedded in an anisotropic black brane solution of type IIB supergravity. The flavor branes undergo a phase transition between a `Minkowski embedding', in which they lie outside of the horizon, and a `black hole embedding', in which they fall into the horizon. This transition depends on two independent dimensionless ratios, which are formed out of the black hole temperature, its anisotropy parameter, and the mass of the flavor degrees of freedom. It happens either at a critical temperature or at a critical anisotropy. A general lesson we learn from this analysis is that the anisotropy, in this particular realization, induces similar effects as the temperature. In particular, increasing the anisotropy bends the branes more and more into the horizon. Moreover, we observe that the transition becomes smoother for higher anisotropies.
Alpha Schottky junction energy source
Litz, Marc S.; Fan, Zhaoyang; Carroll, James J.; Bayne, Stephen
2012-06-01
Isotope batteries offer solutions for long-lived low-power sensor requirements. Alpha emitting isotopes have energy per decay 103 times that of beta emitters. Alpha particles are absorbed within 20 μm of most materials reducing shielding mitigation. However, damage to materials from the alphas limits their practical use. A Schottky Barrier Diode (SBD) geometry is considered with an alpha emitting contact-layer on a diamond-like crystal semiconductor region. The radiation tolerance of diamond, the safety of alpha particles, combined with the internal field of the SBD is expected to generate current useful for low-power electronic devices over decades. Device design parameters and calculations of the expected current are described.
Systematics of Alpha-Radioactivity
Perlman, I.; Ghiorso, A.; Seaborg, G.T.
1949-09-12
Correlations of alpha-decay energies in terms of mass number and atomic number have been made for all of the alpha-emitting species now numbering over 100. For each element isotopes show increase in alpha-energy with decrease in mass number except in the region of 126 neutrons where there is an explainable reversal. This reversal has the effect of creating a region of relatively low alpha-energy and long half-life at low mass numbers for such elements as astatine, emanation, francium, and possibly higher elements as had been noted already for bismuth and polonium. Methods and examples of using alpha-decay data to define the energy surface in the heavy element region are discussed. The regularities in alpha-decay are used for predictions of nuclear properties including prediction of the beta-stable nuclides among the heavy elements. The half-life vs. energy correlations show that the even-even nuclides conform well with existing alpha-decay theory, but all nuclear types with odd nucleons show prohibited decay. The reason for this prohibition is not found in spin changes in the alpha-emission but in the assembly of the components of the alpha particle, and this theory is discussed further in terms of observations made on nuclides having two or more alpha-groups. Using most of the even-even nuclei to define 'normal nuclear radius' calculations are now able to show the shrinkage in the regions of lead and of 126 neutrons to amount to about 10%. The much greater change in 'effective radius' for bismuth isotopes can be dissociated into the effects of odd nucleons superimposed on the actual decrease in nuclear radius. The simple expression r = 1.48 A{sup 1/3} {center_dot} 10{sup -13} cm seems to fit the data for the even-even nuclei outside of the region of 126 neutrons better than more complex functions.
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.)
Anisotropic Internal Friction Damping
Peters, Randall D.
2003-01-01
The mechanical damping properties of sheet polaroid material have been studied with a physical pendulum. The polaroid samples were placed under the knife-edges of the pendulum, which was operated in free-decay at a period in the vicinity of 10 s. With the edges oriented parallel to the direction of the long molecular chains in the polaroid, it was found that the damping was more than 10% smaller than when oriented perpendicular to the chains.
Anisotropic Inflation with General Potentials
Shi, Jiaming; Qiu, Taotao
2015-01-01
Anomalies in recent observational data indicate that there might be some "anisotropic hair" generated in an inflation period. To obtain general information about the effects of this anisotropic hair to inflation models, we studied anisotropic inflation models that involve one vector and one scalar using several types of potentials. We determined the general relationship between the degree of anisotropy and the fraction of the vector and scalar fields, and concluded that the anisotropies behave independently of the potentials. We also generalized our study to the case of multi-directional anisotropies.
Decay properties of heavier nuclei and mass formula
Uno, Masahiro [Ministry of Education, Science and Culture, Tokyo (Japan)
2000-03-01
The stabilities of heavy nuclei, including super-heavy elements, are governed by alpha decay and fission. Some exotic types of decay, such as heavy cluster decay, which does not occur so frequently as to govern stability, have been also reported. The half-time estimations of various types of decay are reviewed. And the possibility of decay, mainly in case of heavy cluster decay, is discussed with Q-value obtained from mass formulae as well. Some topics concerning other types of exotic decay are presented. Recent trends in the research on mass formula are reviewed from the historical point of view, to get perspectives of future development. (Yamamoto, A.)
Gradient expansion for anisotropic hydrodynamics
Florkowski, Wojciech; Spaliński, Michał
2016-01-01
We compute the gradient expansion for anisotropic hydrodynamics. The results are compared with the corresponding expansion of the underlying kinetic-theory model with the collision term treated in the relaxation time approximation. We find that a recent formulation of anisotropic hydrodynamics based on an anisotropic matching principle yields the first three terms of the gradient expansion in agreement with those obtained for the kinetic theory. This gives further support for this particular hydrodynamic model as a good approximation of the kinetic-theory approach. We further find that the gradient expansion of anisotropic hydrodynamics is an asymptotic series, and the singularities of the analytic continuation of its Borel transform indicate the presence of non-hydrodynamic modes.
Photon states in anisotropic media
Deepak Kumar
2002-08-01
Quantum aspects of optical polarization are discussed for waves traveling in anisotropic dielectric media with a view to relate the dynamics of polarization with that of photon spin and its manipulation by classical polarizers.
Application of Anisotropic Texture Components
Eschner, Th.; Fundenberger, J.-J.
1997-01-01
The description of textures in terms of texture components is an established conception in quantitative texture analysis. Recent developments lead to the representation of orientation distribution functions as a weighted sum of model functions, each corresponding to one anisotropic texture component. As was shown previously, an adequate texture description is possible with only a very small number of anisotropic texture components. As a result, textures and texture changes can be described by...
The decay and fission of uranium
According to the Bernai liquid drop alpha particle model, the nuclear structure of uranium contains a core of 38 alpha particles comprised of 5 concentric layers. The innermost core of 4 alpha particles corresponding to the oxygen 16 nuclide is enclosed by 4 more alpha particles giving the structure of the sulphur 32 nuclide. The third layer of 6 alpha particles completes the 14 alpha particle model of nickel 56. The fourth and fifth layers each contain 12 alpha particles. It will be shown that the fifth layer forms a barrier to the natural radioactive decay of uranium isotopes. Furthermore, it appears that whist the fourth layer sets a limit on the minimum size of the larger daughter fragment of the thermal neutron induced fission of a uranium isotope, the third layer sets a limit on the minimum size of the smaller fragment
Raby, Stuart
2002-01-01
We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.
Dislocation dynamics in an anisotropic stripe pattern.
Kamaga, Carina; Ibrahim, Fatima; Dennin, Michael
2004-06-01
The dynamics of dislocations confined to grain boundaries in a striped system are studied using electroconvection in the nematic liquid crystal N4. In electroconvection, a striped pattern of convection rolls forms for sufficiently high driving voltages. We consider the case of a rapid change in the voltage that takes the system from a uniform state to a state consisting of striped domains with two different wave vectors. The domains are separated by domain walls along one axis and a grain boundary of dislocations in the perpendicular direction. The pattern evolves through dislocation motion parallel to the domain walls. We report on features of the dislocation dynamics. The kinetics of the domain motion is quantified using three measures: dislocation density, average domain wall length, and total domain wall length per area. All three quantities exhibit behavior consistent with power-law evolution in time, with the defect density decaying as t(-1/3), the average domain wall length growing as t(1/3), and the total domain wall length decaying as t(-1/5). The two different exponents are indicative of the anisotropic growth of domains in the system. PMID:15244714
Measurement of $\\alpha_{s}$ with Radiative Hadronic Events
Abbiendi, G; Åkesson, P F; Alexander, G; Anagnostou, G; Anderson, K J; Asai, S; Axen, D; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, R J; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, S; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; Dallavalle, M; de Roeck, A; De Wolf, E A; Desch, K; Dienes, B; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, F; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, J; Gruwé, M; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Herten, G; Heuer, R D; Hill, J C; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, D; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krasznahorkays, A Jr; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Lafferty, G D; Landsman, H; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Mashimo, T; Mättig, P; McKenna, J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schiecks, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, J; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L
2008-01-01
Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around the mass of the Z0 boson with the OPAL detector at LEP. The strong coupling alpha S is extracted by comparing data and QCD predictions for event shape observables at average reduced centre-of-mass energies ranging from 24 GeV to 78 GeV, and the energy dependence of alpha S is studied. Our results are consistent with the running of alpha S as predicted by QCD and show that within the uncertainties of our analysis event shapes in hadronic Z0 decays with hard and isolated photon radiation can be described by QCD at reduced centre-of-mass energies. Combining all values from different event shape observables and energies gives alpha S (Mz)=0.1182 pm 0.0015(stat.) pm 0.0101(syst.).
Folding model analysis of alpha radioactivity
Basu, D N
2003-01-01
Radioactive decay of nuclei via emission of $\\alpha$ particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the $\\alpha$-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the $\\alpha$ nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic $\\alpha$-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of $\\alpha$ decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations...
Perturbative expansion of tau hadronic spectral function moments and alpha_s extractions
Beneke, Martin; Jamin, Matthias
2012-01-01
Various moments of the hadronic spectral functions have been employed in the determination of the strong coupling alpha_s from tau decays. In this work we study the behaviour of their perturbative series under different assumptions for the large-order behaviour of the Adler function, extending previous work on the tau hadronic width. We find that the moments can be divided into a small number of classes, whose characteristics depend only on generic features of the moment weight function and Adler function series. Some moments that are commonly employed in alpha_s analyses from tau decays should be avoided because of their perturbative instability. This conclusion is corroborated by a simplified alpha_s extraction from individual moments. Furthermore, under reasonable assumptions for the higher-order behaviour of the perturbative series, fixed-order perturbation theory (FOPT) provides the preferred framework for the renormalization group improvement of all moments that show good perturbative behaviour. Finally...
Fetal alpha globulin; AFP ... Greater than normal levels of AFP may be due to: Cancer in testes , ovaries, biliary (liver secretion) tract, stomach, or pancreas Cirrhosis of the liver Liver cancer ...
On the ^{221}Rn \\to ^{221}Fr Decay Scheme
Gromov, K Ya; Norseev, Yu V; Samatov, Zh K; Sergienko, V A; Fominykh, V I; Chumin, V G
2002-01-01
The results of investigating the ^{221}Rn beta^{-}-decay and the ^{225}Ac alpha-decay are compared. It is shown that ^{221}Fr levels at 145.9 and 393.2 keV are excited at the ^{221}Rn decay. Intensities and reduced probabilities of the beta^{-}-decay to the ^{221}Fr levels are determined. A conclusion is drawn that the parity of the ^{221}Rn ground state is positive.
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
Continuum mechanics of anisotropic materials
Cowin, Stephen C
2013-01-01
Continuum Mechanics of Anisotropic Materials(CMAM) presents an entirely new and unique development of material anisotropy in the context of an appropriate selection and organization of continuum mechanics topics. These features will distinguish this continuum mechanics book from other books on this subject. Textbooks on continuum mechanics are widely employed in engineering education, however, none of them deal specifically with anisotropy in materials. For the audience of Biomedical, Chemical and Civil Engineering students, these materials will be dealt with more frequently and greater accuracy in their analysis will be desired. Continuum Mechanics of Anisotropic Materials' author has been a leader in the field of developing new approaches for the understanding of anisotropic materials.
Superlens from complementary anisotropic metamaterials
Li, G. X.; Tam, H. L.; Wang, F. Y.; Cheah, K. W.
2007-12-01
Metamaterials with isotropic property have been shown to possess novel optical properties such as a negative refractive index that can be used to design a superlens. Recently, it was shown that metamaterials with anisotropic property can translate the high-frequency wave vector k values from evanescence to propagating. However, electromagnetic waves traveling in single-layer anisotropic metamaterial produce diverging waves of different spatial frequency. In this work, it is shown that, using bilayer metamaterials that have complementary anisotropic property, the diverging waves are recombined to produce a subwavelength image, i.e., a superlens device can be designed. The simulation further shows that the design can be achieved using a metal/oxide multilayer, and a resolution of 30 nm can be easily obtained in the optical frequency range.
Dynamical analysis of anisotropic inflation
Karčiauskas, Mindaugas
2016-06-01
The inflaton coupling to a vector field via the f(φ)2F μνFμν term is used in several contexts in the literature, such as to generate primordial magnetic fields, to produce statistically anisotropic curvature perturbation, to support anisotropic inflation, and to circumvent the η-problem. In this work, I perform dynamical analysis of this system allowing for the most general Bianchi I initial conditions. I also confirm the stability of attractor fixed points along phase-space directions that had not been investigated before.
Latest developments in anisotropic hydrodynamics
Tinti, Leonardo
2015-01-01
We discuss the leading order of anisotropic hydrodynamics expansion. It has already been shown that in the (0+1) and (1+1)-dimensional cases it is consistent with the second order viscous hydrodynamics, and it provides a striking agreement with the exact solutions of the Boltzmann equation. Quite recently, a new set of equations has been proposed for the leading order of anisotropic hydrodynamics, which is consistent with the second order viscous hydrodynamics in the most general (3+1)-dimensional case, and does not require a next-to-leading treatment for describing pressure anisotropies in the transverse plane.
Anisotropic hydrodynamics: Motivation and methodology
In this proceedings contribution I review recent progress in our understanding of the bulk dynamics of relativistic systems that possess potentially large local rest frame momentum-space anisotropies. In order to deal with these momentum-space anisotropies, a reorganization of relativistic viscous hydrodynamics can be made around an anisotropic background, and the resulting dynamical framework has been dubbed “anisotropic hydrodynamics”. I also discuss expectations for the degree of momentum-space anisotropy of the quark–gluon plasma generated in relativistic heavy ion collisions at RHIC and LHC from second-order viscous hydrodynamics, strong-coupling approaches, and weak-coupling approaches
Secondary Cosmic Positrons in an Anisotropic Diffusion Model
Kappl, Rolf
2016-01-01
One aim of cosmic ray measurements is the search for possible signatures of annihilating or decaying dark matter. The so-called positron excess has attracted a lot of attention in this context. On the other hand it has been proposed that the data might challenge the established diffusion model for cosmic ray propagation. We investigate an anisotropic diffusion model by solving the corresponding equations analytically. Depending on the propagation parameters we find that the spectral features of the positron spectrum are affected significantly. We also discuss the influence of the anisotropy on hadronic spectra.
Anatomy of the pQCD approach to the baryonic decays {lambda}{sub b} {yields} p{pi}, pK
Lue, Cai-Dian; Wang, Yu-Ming; Zou, Hao [Chinese Acadamy of Sciences (China). Institute of High Energy Physics and Theoretical Physics Center for Science Facilities; Ali, Ahmed [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, Gustav [Hamburg Univ. (Germany). II. Institut fuer Theoretische Physik
2009-06-15
We calculate the CP-averaged branching ratios and CP-violating asymmetries for the two-body charmless hadronic decays {lambda}{sub b} {yields} p{pi}, pK in the perturbative QCD (pQCD) approach to lowest order in {alpha}{sub s}. The baryon distribution amplitudes involved in the factorization formulae are considered to the leading twist accuracy and the distribution amplitudes of the proton are expanded to the next-to-leading conformal spin (i.e., ''P''-waves), the moments of which are determined from QCD sum rules. Our work shows that the contributions from the factorizable diagrams in {lambda}{sub b} {yields} p{pi}, pK decays are much smaller compared to the nonfactorizable diagrams in the conventional pQCD approach. We argue that this reflects the estimates of the {lambda}{sub b} {yields} p transition form factors in the k{sub T} factorization approach, which are found typically an order of magnitude smaller than those estimated in the light-cone sum rules and in the non-relativistic quark model. As an alternative, we adopt a hybrid pQCD approach, in which we compute the factorizable contributions with the {lambda}{sub b} {yields} p form factors taken from the light cone QCD sum rules. The non-factorizable diagrams are evaluated utilizing the conventional pQCD formalism which is free from the endpoint singularities. The predictions worked out here are confronted with the recently available data from the CDF collaboration on the branching ratios and the direct CP asymmetries for the decays {lambda}{sub b} {yields} p{pi}, and {lambda}{sub b} {yields} pK. The asymmetry parameter {alpha} relevant for the anisotropic angular distribution of the emitted proton in the polarized {lambda}{sub b} baryon decays is also calculated for the two decay modes. (orig.)
A study of the Th231 excited levels from the alpha decay of the U235, is carried out. The alpha particle spectrum was measured by means of a semiconductor counter spectrometer with an effective resolution of 18 keV. Nineteen new lines were identified. The gamma-ray spectrum was measured with thin samples of U235, free from decay products, and in such geometrical conditions, that most of the interference effects were eliminated. The gamma-gamma coincidence spectra have made easier a better knowledge of the transition between the several levels. (Author) 110 refs