Single-particle Glauber matrix elements
International Nuclear Information System (INIS)
Oset, E.; Strottman, D.
1983-01-01
The single-particle matrix elements of the Glauber profile function are tabulated for harmonic oscillator single-particle wave functions. The tables are presented in such a manner as to be applicable if the hadron--nucleon elementary scattering amplitude is specified by either a partial wave expansion or a Gaussian in momentum transfer squared. The table is complete through the 1 g/sub 9/2/ orbital and contains entries for the 3s/sub 1/2/ orbital for use if realistic wave functions are expanded in terms of harmonic oscillator functions
Single-particle density matrix of liquid 4He
International Nuclear Information System (INIS)
Vakarchuk, I.A.
2008-01-01
The density single-particle matrix in the coordinate notation was calculated based on the expression for the interacting Bose-particle N system density matrix. Under the low temperatures the mentioned matrix in the first approximation enables to reproduce the Bogoliubov theory results. In the classical terms the mentioned theory enables to reproduce the results of the theory of the classical fluids in the approximation of the chaotic phases. On the basis of the density single-particle matrix one managed to obtain the function of the pulse distribution of the particles, the Bose-liquid average kinetic energy, and to study the Bose-Einstein condensation phenomenon [ru
International Nuclear Information System (INIS)
Brown, B.A.; Wildenthal, B.H.
1983-01-01
The magnetic dipole moments of states in mirror pairs of the sd-shell nuclei and the strengths of the Gamow-Teller beta decays which connect them are compared with predictions based on mixed-configuration shell-model wave functions. From this analysis we extract the average effective values of the single-particle matrix elements of the l, s, and [Y/sup( 2 )xs]/sup( 1 ) components of the M1 and Gamow-Teller operators acting on nucleons in the 0d/sub 5/2/, 1s/sub 1/2/, and 0d/sub 3/2/ orbits. These results are compared with the recent calculations by Towner and Khanna of the corrections to the free-nucleon values of these matrix elements which arise from the effects of isobar currents, mesonic-exchange currents, and mixing with configurations outside the sd shell
Single-particle density matrix and superfluidity in the two-dimensional Bose Coulomb fluid
International Nuclear Information System (INIS)
Minguzzi, A.; Tosi, M.P.; Davoudi, B.
2002-01-01
A study by Magro and Ceperley [Phys. Rev. Lett. 73, 826 (1994)] has shown that the ground state of the two-dimensional fluid of charged bosons with logarithmic interactions is not Bose condensed, but exhibits algebraic off-diagonal order in the single-particle density matrix ρ(r). We use a hydrodynamic Hamiltonian expressed in terms of density and phase operators, in combination with an f-sum rule on the superfluid fraction, to reproduce these results and to extend the evaluation of the density matrix to finite temperature T. This approach allows us to treat the liquid as a superfluid in the absence of a condensate. The algebraic decay of the one-body density matrix is due to correlations between phase fluctuations, and we find that the exponent in the power law is determined by the superfluid density n s (T). We also find that the plasmon gap in the single-particle energy spectrum at long wavelengths decreases with increasing T and closes at the critical temperature for the onset of superfluidity
International Nuclear Information System (INIS)
Birjiniuk, Alona; Doyle, Patrick S; Billings, Nicole; Ribbeck, Katharina; Nance, Elizabeth; Hanes, Justin
2014-01-01
Biofilms are communities of surface-adherent bacteria surrounded by secreted polymers known as the extracellular polymeric substance. Biofilms are harmful in many industries, and thus it is of great interest to understand their mechanical properties and structure to determine ways to destabilize them. By performing single particle tracking with beads of varying surface functionalization it was found that charge interactions play a key role in mediating mobility within biofilms. With a combination of single particle tracking and microrheological concepts, it was found that Escherichia coli biofilms display height dependent charge density that evolves over time. Statistical analyses of bead trajectories and confocal microscopy showed inter-connecting micron scale channels that penetrate throughout the biofilm, which may be important for nutrient transfer through the system. This methodology provides significant insight into a particular biofilm system and can be applied to many others to provide comparisons of biofilm structure. The elucidation of structure provides evidence for the permeability of biofilms to microscale objects, and the ability of a biofilm to mature and change properties over time. (paper)
Development of elemental technique for single particle irradiation system to cell
International Nuclear Information System (INIS)
Yukawa, Masae; Yasuda, Nakahiro; Matsumoto, Kenichi
2004-01-01
A single-ion microbeam facility (SPICE: Single Particle Irradiation system to Cell) are constructing at National Institute of Radiological Sciences (NIRS). The system was design to deliver the defined number of helium or hydrogen ions into an area smaller than the nuclei of cells in culture on thin films. The beam will be focused into 2μmθ (in diameter) by triplet-Q magnet. We have established the monitoring system using thin plastic scintillator, IIT and charge-coupled device (CCD) camera to measure the size and position of microbeam. The monitoring system for microbeam has been evaluated in the middle energy course using 4.3 MeV protons. We have designed and made two new type collimators to get the microbeam, and have evaluated its scattering effect. We have confirmed that the collimated beam spot (100 ions/sec) was observed in CCD image as small light spot. This system is now installed into SPICE apparatus. (authors)
Electromagnetic matrix elements in baryons
International Nuclear Information System (INIS)
Lipkin, H.J.; Moinester, M.A.
1992-01-01
Some simple symmetry relations between matrix elements of electromagnetic operators are investigated. The implications are discussed for experiments to study hyperon radiative transitions and polarizabilities and form factors. (orig.)
Single-particle basis and translational invariance in microscopic nuclear calculations
International Nuclear Information System (INIS)
Ehfros, V.D.
1977-01-01
The approach to the few-body problem is considered which allows to use the simple single-particle basis without violation of the translation invariance. A method is proposed to solve the nuclear reaction problems in the single-particle basis. The method satisfies the Pauli principle and the translation invariance. Calculation of the matrix elements of operators is treated
Bauer, Susanne E.; Ault, Andrew; Prather, Kimberly A.
2013-01-01
Aerosol particles in the atmosphere are composed of multiple chemical species. The aerosol mixing state, which describes how chemical species are mixed at the single-particle level, provides critical information on microphysical characteristics that determine the interaction of aerosols with the climate system. The evaluation of mixing state has become the next challenge. This study uses aerosol time-of-flight mass spectrometry (ATOFMS) data and compares the results to those of the Goddard Institute for Space Studies modelE-MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) model, a global climate model that includes a detailed aerosol microphysical scheme. We use data from field campaigns that examine a variety of air mass regimens (urban, rural, and maritime). At all locations, polluted areas in California (Riverside, La Jolla, and Long Beach), a remote location in the Sierra Nevada Mountains (Sugar Pine) and observations from Jeju (South Korea), the majority of aerosol species are internally mixed. Coarse aerosol particles, those above 1 micron, are typically aged, such as coated dust or reacted sea-salt particles. Particles below 1 micron contain large fractions of organic material, internally-mixed with sulfate and black carbon, and few external mixtures. We conclude that observations taken over multiple weeks characterize typical air mass types at a given location well; however, due to the instrumentation, we could not evaluate mass budgets. These results represent the first detailed comparison of single-particle mixing states in a global climate model with real-time single-particle mass spectrometry data, an important step in improving the representation of mixing state in global climate models.
International Nuclear Information System (INIS)
Feresin, A.P.; Guseva, I.S.
1984-01-01
Single-particle matrix elements for magnetic quadrupole gamma radiation in odd deformed nuclei, calculated with the aid of Nilsson-potential wave functions, are presented. Also given are the internal conversion penetration matrix elements, calculated in the same manner. The penetration matrix elements are needed to estimate the nuclear penetration parameter, which determines the deviation of experimental internal conversion coefficients from their standard values given in tables. Matrix elements are given for transitions between all pairs of Nilsson single-particle states with ΔN = 1 and ΔK = 0, 1, and 2 for the nuclear shells with 4< or =N< or =7 and for the two deformation values epsilon = 0.2 and 0.3
Analytic matrix elements with shifted correlated Gaussians
DEFF Research Database (Denmark)
Fedorov, D. V.
2017-01-01
Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics.......Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics....
International Nuclear Information System (INIS)
Siemens, P.J.; Jensen, A.S.
1985-01-01
It is shown that the opening of the 3-quasiparticle continuum at 3Δ sets the energy scale for the enhancement of the effective mass near the Fermi surface of nuclei. The authors argue that the spreading width of single-particle states due to coupling with low-lying collective modes is qualitatively different from the two-body collision mechanism, and contributes little to the single-particle lifetime in the sense of the optical model. (orig.)
Rovibrational matrix elements of the multipole moments
Indian Academy of Sciences (India)
Rovibrational matrix elements of the multipole moments ℓ up to rank 10 and of the linear polarizability of the H2 molecule in the condensed phase have been computed taking into account the effect of the intermolecular potential. Comparison with gas phase matrix elements shows that the effect of solid state interactions is ...
Analytic vibrational matrix elements for diatomic molecules
International Nuclear Information System (INIS)
Bouanich, J.P.; Ogilvie, J.F.; Tipping, R.H.
1986-01-01
The vibrational matrix elements and expectation values for a diatomic molecule, including the rotational dependence, are calculated for powers of the reduced displacement in terms of the parameters of the Dunham potential-energy function. (orig.)
Lattice results for heavy light matrix elements
International Nuclear Information System (INIS)
Soni, A.
1994-09-01
Lattice results for heavy light matrix elements are reviewed and some of their implications are very briefly discussed. Despite the fact that in most cases the lattice results for weak matrix elements at the moment have only a modest accuracy of about 20--30% they already have important phenomenological repercussions; e.g. for V td /V ts , x s /x d and B → K*γ
Matrix Elements in Fermion Dynamical Symmetry Model
Institute of Scientific and Technical Information of China (English)
LIU Guang-Zhou; LIU Wei
2002-01-01
In a neutron-proton system, the matrix elements of the generators for SO(8) × SO(8) symmetry areconstructed explicitly, and with these matrix elements the low-lying excitation spectra obtained by diagonalization arepresented. The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe, Ba, andCe isotopes are calculated, and comparison with the experimental results is carried out.
Matrix Elements in Fermion Dynamical Symmetry Model
Institute of Scientific and Technical Information of China (English)
LIUGuang－Zhou; LIUWei
2002-01-01
In a neutron-proton system,the matrix elements of the generators for SO(8)×SO(8) symmetry are constructed exp;icitly,and with these matrix elements the low-lying excitation spsectra obtained by diagonalization are presented.The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe,Ba,and Ce isotopes are calculated,and comparison with the experimental results is carried out.
Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y
2000-01-01
Using the SU sub 6 quark-model baryon-baryon interaction which was recently developed by the Kyoto-Niigata group, we calculate N N, LAMBDA N and SIGMA N G--matrices in ordinary nuclear matter. Following the Scheerbaum's prescription, the strength of the single-particle spin-orbit potential S sub B is quantitatively discussed. The S subLAMBDA becomes small because of the cancellation between spin-orbit and anti-symmetric spin-orbit components. The short-range correlation is found to further reduce S subLAMBDA.
The finite element response matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-02-01
A new technique is developed with an alternative formulation of the response matrix method implemented with the finite element scheme. Two types of response matrices are generated from the Galerkin solution to the weak form of the diffusion equation subject to an arbitrary current and source. The piecewise polynomials are defined in two levels, the first for the local (assembly) calculations and the second for the global (core) response matrix calculations. This finite element response matrix technique was tested in two 2-dimensional test problems, 2D-IAEA benchmark problem and Biblis benchmark problem, with satisfatory results. The computational time, whereas the current code is not extensively optimized, is of the same order of the well estabilished coarse mesh codes. Furthermore, the application of the finite element technique in an alternative formulation of response matrix method permits the method to easily incorporate additional capabilities such as treatment of spatially dependent cross-sections, arbitrary geometrical configurations, and high heterogeneous assemblies. (Author) [pt
Renormalon ambiguities in NRQCD operator matrix elements
International Nuclear Information System (INIS)
Bodwin, G.T.; Chen, Y.
1999-01-01
We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass. copyright 1999 The American Physical Society
Energy Technology Data Exchange (ETDEWEB)
Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics
1993-09-01
We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.
International Nuclear Information System (INIS)
Bodmer, A.R.; Usmani, Q.N.; Sami, M.
1993-01-01
We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei
Single particle detecting telescope system
International Nuclear Information System (INIS)
Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.
1981-01-01
We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement
Proton decay matrix elements from lattice QCD
International Nuclear Information System (INIS)
Aoki, Yasumichi; Shintani, Eigo
2012-01-01
We report on the calculation of the matrix elements of nucleon to pseudoscalar decay through a three quark operator, a part of the low-energy, four-fermion, baryon-number-violating operator originating from grand unified theories. The direct calculation of the form factors using domain-wall fermions on the lattice, incorporating the u, d and s sea-quarks effects yields the results with all the relevant systematic uncertainties controlled for the first time.
Centroids of effective interactions from measured single-particle energies: An application
International Nuclear Information System (INIS)
Cole, B.J.
1990-01-01
Centroids of the effective nucleon-nucleon interaction for the mass region A=28--64 are extracted directly from experimental single-particle spectra, by comparing single-particle energies relative to different cores. Uncertainties in the centroids are estimated at approximately 100 keV, except in cases of exceptional fragmentation of the single-particle strength. The use of a large number of inert cores allows the dependence of the interaction on mass or model space to be investigated. The method permits accurate empirical modifications to be made to realistic interactions calculated from bare nucleon-nucleon potentials, which are known to possess defective centroids in many cases. In addition, the centroids can be used as input to the more sophisticated fitting procedures that are employed to produce matrix elements of the effective interaction
The finite element response Matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-01-01
A new method for global reactor core calculations is described. This method is based on a unique formulation of the response matrix method, implemented with a higher order finite element method. The unique aspects of this approach are twofold. First, there are two levels to the overall calculational scheme: the local or assembly level and the global or core level. Second, the response matrix scheme, which is formulated at both levels, consists of two separate response matrices rather than one response matrix as is generally the case. These separate response matrices are seen to be quite beneficial for the criticality eigenvalue calculation, because they are independent of k /SUB eff/. The response matrices are generated from a Galerkin finite element solution to the weak form of the diffusion equation, subject to an arbitrary incoming current and an arbitrary distributed source. Calculational results are reported for two test problems, the two-dimensional International Atomic Energy Agency benchmark problem and a two-dimensional pressurized water reactor test problem (Biblis reactor), and they compare well with standard coarse mesh methods with respect to accuracy and efficiency. Moreover, the accuracy (and capability) is comparable to fine mesh for a fraction of the computational cost. Extension of the method to treat heterogeneous assemblies and spatial depletion effects is discussed
A new seniority scheme for non-degenerate single particle orbits
International Nuclear Information System (INIS)
Otsuka, T.; Arima, A.
1978-01-01
A new method is proposed in the treatment of the seniority scheme. The method enables one to evaluate analytically the contribution from J = 0 Cooper pairs in non-degenerate single-particle orbits to many-body matrix elements. It includes the SU(2) quasi-spin and the BCS approximation as two extreme limits. The effect of particle number conservation is properly taken into account. (Auth.)
Single particle distributions, ch.2
International Nuclear Information System (INIS)
Blokzijl, R.
1977-01-01
A survey of inclusive single particle distributions is given for various particles. A comparison of particle cross-sections measured in K - p experiments at different center of mass energies shows that some of these cross-sections remain almost constant over a wide range of incoming K - momenta
An Explicit Consistent Geometric Stiffness Matrix for the DKT Element
Directory of Open Access Journals (Sweden)
Eliseu Lucena Neto
Full Text Available Abstract A large number of references dealing with the geometric stiffness matrix of the DKT finite element exist in the literature, where nearly all of them adopt an inconsistent form. While such a matrix may be part of the element to treat nonlinear problems in general, it is of crucial importance for linearized buckling analysis. The present work seems to be the first to obtain an explicit expression for this matrix in a consistent way. Numerical results on linear buckling of plates assess the element performance either with the proposed explicit consistent matrix, or with the most commonly used inconsistent matrix.
Improved method for eliminating center-of-mass coordinates from matrix elements in oscillator basis
International Nuclear Information System (INIS)
Richardson, R.H.; Shapiro, J.Y.
1986-01-01
This paper presents a concise, efficient method of reducing potential energy matrix elements to relative coordinates, when one is using an oscillator basis. It is especially suited to computer calculations. One nice feature of the method is its modular form, which allows a wide range of calculations. Separate FORTRAN subroutines have been written which calculate and store tables of the one-dimensional brackets of an equation that is presented and the single particle brackets from the isotropic to the axially symmetric oscillator equations. The tables are used by other subroutines which calculate the modified brackets and the brackets with spin. The methods developed here are a substantial improvement over what has been done heretofore, and open up new possibilities for performing nuclear structure calculations
Single Particle Entropy in Heated Nuclei
International Nuclear Information System (INIS)
Guttormsen, M.; Chankova, R.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Syed, N. U. H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.
2006-01-01
The thermal motion of single particles represents the largest contribution to level density (or entropy) in atomic nuclei. The concept of single particle entropy is presented and shown to be an approximate extensive (additive) quantity for mid-shell nuclei. A few applications of single particle entropy are demonstrated
Hadronic matrix elements in lattice QCD
International Nuclear Information System (INIS)
Jaeger, Benjamin
2014-01-01
The lattice formulation of Quantum ChromoDynamics (QCD) has become a reliable tool providing an ab initio calculation of low-energy quantities. Despite numerous successes, systematic uncertainties, such as discretisation effects, finite-size effects, and contaminations from excited states, are inherent in any lattice calculation. Simulations with controlled systematic uncertainties and close to the physical pion mass have become state-of-the-art. We present such a calculation for various hadronic matrix elements using non-perturbatively O(a)-improved Wilson fermions with two dynamical light quark flavours. The main topics covered in this thesis are the axial charge of the nucleon, the electro-magnetic form factors of the nucleon, and the leading hadronic contributions to the anomalous magnetic moment of the muon. Lattice simulations typically tend to underestimate the axial charge of the nucleon by 5-10%. We show that including excited state contaminations using the summed operator insertion method leads to agreement with the experimentally determined value. Further studies of systematic uncertainties reveal only small discretisation effects. For the electro-magnetic form factors of the nucleon, we see a similar contamination from excited states as for the axial charge. The electro-magnetic radii, extracted from a dipole fit to the momentum dependence of the form factors, show no indication of finite-size or cutoff effects. If we include excited states using the summed operator insertion method, we achieve better agreement with the radii from phenomenology. The anomalous magnetic moment of the muon can be measured and predicted to very high precision. The theoretical prediction of the anomalous magnetic moment receives contribution from strong, weak, and electro-magnetic interactions, where the hadronic contributions dominate the uncertainties. A persistent 3σ tension between the experimental determination and the theoretical calculation is found, which is
Elements of matrix modeling and computing with Matlab
White, Robert E
2006-01-01
As discrete models and computing have become more common, there is a need to study matrix computation and numerical linear algebra. Encompassing a diverse mathematical core, Elements of Matrix Modeling and Computing with MATLAB examines a variety of applications and their modeling processes, showing you how to develop matrix models and solve algebraic systems. Emphasizing practical skills, it creates a bridge from problems with two and three variables to more realistic problems that have additional variables. Elements of Matrix Modeling and Computing with MATLAB focuses on seven basic applicat
Analytic vibration-rotational matrix elements for diatomic molecules
International Nuclear Information System (INIS)
Bouanich, J.P.
1987-01-01
The vibration-rotational matrix elements for infrared or Raman transitions vJ → v'J' of diatomic molecules are calculated for powers of the reduced displacement X from parameters of the Dunham potential-energy function. (orig.)
Hierarchy of Poisson brackets for elements of a scattering matrix
International Nuclear Information System (INIS)
Konopelchenko, B.G.; Dubrovsky, V.G.
1984-01-01
The infinite family of Poisson brackets [Ssub(i1k1) (lambda 1 ), Ssub(i2k2) (lambda 2 )]sub(n) (n=0, 1, 2, ...) between the elements of a scattering matrix is calculated for the linear matrix spectral problem. (orig.)
Direct calculation of off-diagonal matrix elements
International Nuclear Information System (INIS)
Killingbeck, J P; Jolicard, G
2011-01-01
Gauss elimination is used in a sequence of calculations which give the squares of the off-diagonal matrix elements of x between quartic oscillator eigenstates, in a modification of the original sum rule approach of Tipping et al to the problem. New and more flexible methods are then devised and tested and are shown to permit the isolation and calculation of individual squared matrix elements of x and x 2 .
Finite size effects of a pion matrix element
International Nuclear Information System (INIS)
Guagnelli, M.; Jansen, K.; Palombi, F.; Petronzio, R.; Shindler, A.; Wetzorke, I.
2004-01-01
We investigate finite size effects of the pion matrix element of the non-singlet, twist-2 operator corresponding to the average momentum of non-singlet quark densities. Using the quenched approximation, they come out to be surprisingly large when compared to the finite size effects of the pion mass. As a consequence, simulations of corresponding nucleon matrix elements could be affected by finite size effects even stronger which could lead to serious systematic uncertainties in their evaluation
Coulomb matrix elements in multi-orbital Hubbard models.
Bünemann, Jörg; Gebhard, Florian
2017-04-26
Coulomb matrix elements are needed in all studies in solid-state theory that are based on Hubbard-type multi-orbital models. Due to symmetries, the matrix elements are not independent. We determine a set of independent Coulomb parameters for a d-shell and an f-shell and all point groups with up to 16 elements (O h , O, T d , T h , D 6h , and D 4h ). Furthermore, we express all other matrix elements as a function of the independent Coulomb parameters. Apart from the solution of the general point-group problem we investigate in detail the spherical approximation and first-order corrections to the spherical approximation.
Empirical Coulomb matrix elements and the mass of 22Al
International Nuclear Information System (INIS)
Whitehead, R.R.; Watt, A.; Kelvin, D.; Rutherford, H.J.
1976-01-01
An attempt has been made to obtain a set of Coulomb matrix elements which fit the known Coulomb energy shifts in the nuclei of mass 18 to 22. The interaction obtained fits the data well with only a few exceptions, one of these being the Coulomb shift of the notorious third 0 + state in 18 Ne. These Coulomb matrix elements are used together with the Chung-Wildenthal interaction to obtain a new prediction for the mass excess of 22 Al. The results indicate that 22 Al should be bound against proton emission. (Auth.)
The effects of flavour symmetry breaking on hadron matrix elements
International Nuclear Information System (INIS)
Cooke, A.N.; Horsley, R.; Pleiter, D.; Zanotti, J.M.
2012-12-01
By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We find the expansions to be highly constrained along a mass trajectory where the singlet quark mass is held constant, which proves beneficial for extrapolations of 2+1 flavour lattice data to the physical point. We investigate these effects numerically via a lattice calculation of the flavour-conserving and flavour-changing matrix elements of the vector and axial operators between octet baryon states.
Rotational covariance and light-front current matrix elements
International Nuclear Information System (INIS)
Keister, B.D.
1994-01-01
Light-front current matrix elements for elastic scattering from hadrons with spin 1 or greater must satisfy a nontrivial constraint associated with the requirement of rotational covariance for the current operator. Using a model ρ meson as a prototype for hadronic quark models, this constraint and its implications are studied at both low and high momentum transfers. In the kinematic region appropriate for asymptotic QCD, helicity rules, together with the rotational covariance condition, yield an additional relation between the light-front current matrix elements
The Matrix Element Method at Next-to-Leading Order
Campbell, John M.; Giele, Walter T.; Williams, Ciaran
2012-01-01
This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of...
The effects of flavour symmetry breaking on hadron matrix elements
Energy Technology Data Exchange (ETDEWEB)
Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Pleiter, D. [Juelich Research Centre (Germany); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Zanotti, J.M. [Adelaide Univ. (Australia). School of Chemistry and Physics
2012-12-15
By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We find the expansions to be highly constrained along a mass trajectory where the singlet quark mass is held constant, which proves beneficial for extrapolations of 2+1 flavour lattice data to the physical point. We investigate these effects numerically via a lattice calculation of the flavour-conserving and flavour-changing matrix elements of the vector and axial operators between octet baryon states.
Nucleon matrix elements using the variational method in lattice QCD
International Nuclear Information System (INIS)
Dragos, J.; Kamleh, W.; Leinweber, D.B.; Zanotti, J.M.; Rakow, P.E.L.; Young, R.D.; Adelaide Univ., SA
2016-06-01
The extraction of hadron matrix elements in lattice QCD using the standard two- and threepoint correlator functions demands careful attention to systematic uncertainties. One of the most commonly studied sources of systematic error is contamination from excited states. We apply the variational method to calculate the axial vector current g_A, the scalar current g_S and the quark momentum fraction left angle x right angle of the nucleon and we compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.
Optimization of Coil Element Configurations for a Matrix Gradient Coil.
Kroboth, Stefan; Layton, Kelvin J; Jia, Feng; Littin, Sebastian; Yu, Huijun; Hennig, Jurgen; Zaitsev, Maxim
2018-01-01
Recently, matrix gradient coils (also termed multi-coils or multi-coil arrays) were introduced for imaging and B 0 shimming with 24, 48, and even 84 coil elements. However, in imaging applications, providing one amplifier per coil element is not always feasible due to high cost and technical complexity. In this simulation study, we show that an 84-channel matrix gradient coil (head insert for brain imaging) is able to create a wide variety of field shapes even if the number of amplifiers is reduced. An optimization algorithm was implemented that obtains groups of coil elements, such that a desired target field can be created by driving each group with an amplifier. This limits the number of amplifiers to the number of coil element groups. Simulated annealing is used due to the NP-hard combinatorial nature of the given problem. A spherical harmonic basis set up to the full third order within a sphere of 20-cm diameter in the center of the coil was investigated as target fields. We show that the median normalized least squares error for all target fields is below approximately 5% for 12 or more amplifiers. At the same time, the dissipated power stays within reasonable limits. With a relatively small set of amplifiers, switches can be used to sequentially generate spherical harmonics up to third order. The costs associated with a matrix gradient coil can be lowered, which increases the practical utility of matrix gradient coils.
Effects of quenching and partial quenching on penguin matrix elements
Golterman, Maarten; Pallante, Elisabetta
2001-01-01
In the calculation of non-leptonic weak decay rates, a "mismatch" arises when the QCD evolution of the relevant weak hamiltonian down to hadronic scales is performed in unquenched QCD, but the hadronic matrix elements are then computed in (partially) quenched lattice QCD. This mismatch arises
S-matrix elements from T-duality
International Nuclear Information System (INIS)
Babaei Velni, Komeil; Garousi, Mohammad R.
2013-01-01
Recently it has been speculated that the S-matrix elements satisfy the Ward identity associated with the T-duality. This indicates that a group of S-matrix elements is invariant under the linear T-duality transformations on the external states. If one evaluates one component of such T-dual multiplet, then all other components may be found by the simple use of the linear T-duality. The assumption that fields must be independent of the Killing coordinate, however, may cause, in some cases, the T-dual multiplet not to be gauge invariant. In those cases, the S-matrix elements contain more than one T-dual multiplet which are intertwined by the gauge symmetry. In this paper, we apply the T-dual Ward identity on the S-matrix element of one RR (p−3)-form and two NSNS states on the world volume of a D p -brane to find its corresponding T-dual multiplet. In the case that the RR potential has two transverse indices, the T-dual multiplet is gauge invariant, however, in the case that it has one transverse index the multiplet is not gauge invariant. We find a new T-dual multiplet in this case by imposing the gauge symmetry. We show that the multiplets are reproduced by explicit calculation, and their low energy contact terms at order α ′2 are consistent with the existing couplings in the literature
Structure of nuclear transition matrix elements for neutrinoless ...
Indian Academy of Sciences (India)
Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...
Rovibrational matrix elements of the multipole moments and of the ...
Indian Academy of Sciences (India)
The rovibrational matrix elements of the multipole moments and polarizability of molecules find applications in the study of infrared spectra, intermolecular potential and collision-induced absorption phenomena, especially in homonuclear molecules. Because of its simplicity and fundamental importance, the hydrogen ...
Structure of nuclear transition matrix elements for neutrinoless ...
Indian Academy of Sciences (India)
Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double-β decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...
Application of FIRE for the calculation of photon matrix elements
Indian Academy of Sciences (India)
to evaluate the two-loop Feynman diagrams for the photon matrix element of the ... sum of scalar Feynman integrals to a linear combination of a few master integrals. .... Then, FIRE is used to express these scalar integrals as a linear combi-.
Single particle dynamics in circular accelerators
International Nuclear Information System (INIS)
Ruth, R.D.
1986-10-01
The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)
Weak matrix elements on the lattice - Circa 1995
International Nuclear Information System (INIS)
Soni, A.
1995-01-01
Status of weak matrix elements is reviewed. In particular, e'/e, B → K*γ, B B and B B , are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarised. For e'/e the need for the relevant matrix elements is stressed in view of the forthcoming improved experiments. For some of the operators, (e.g. O 6 ), even bound on their matrix elements would be very helpful. On B → K degrees γ, a constant behavior of T 2 appears disfavored although dependence of T 2 could, of course, be milder than a simple pole. Improved data is badly needed to settle this important issue firmly, especially in view of its ramification for extractions of V td from B → ργ. On B κ , the preliminary result from JLQCD appears to contradict Sharpe et al. JLQCD data seems to fit very well to linear α dependence and leads to an appreciably lower value of B κ . Four studies of B κ in the open-quotes fullclose quotes (n f = 2) theory indicate very little quenching effects on B κ ; the full theory value seems to be just a little less than the quenched result. Based on expectations from HQET, analysis of B-parameter (B h ell) for the heavy-light mesons via B h ell) = constant + constants'/m h ell is suggested. A summary of an illustrative sample of hadron matrix elements is given and constraints on CKM parameters (e.g. V td /V ts , on the unitarity triangle and on x s /x d , emerging from the lattice calculations along with experimental results are briefly discussed. In quite a few cases, for the first time, some indication of quenching errors on weak matrix elements are now becoming available
Kota, V K B; Chavda, N D; Sahu, R
2006-04-01
Interacting many-particle systems with a mean-field one-body part plus a chaos generating random two-body interaction having strength lambda exhibit Poisson to Gaussian orthogonal ensemble and Breit-Wigner (BW) to Gaussian transitions in level fluctuations and strength functions with transition points marked by lambda = lambda c and lambda = lambda F, respectively; lambda F > lambda c. For these systems a theory for the matrix elements of one-body transition operators is available, as valid in the Gaussian domain, with lambda > lambda F, in terms of orbital occupation numbers, level densities, and an integral involving a bivariate Gaussian in the initial and final energies. Here we show that, using a bivariate-t distribution, the theory extends below from the Gaussian regime to the BW regime up to lambda = lambda c. This is well tested in numerical calculations for 6 spinless fermions in 12 single-particle states.
Glueball Spectrum and Matrix Elements on Anisotropic Lattices
Energy Technology Data Exchange (ETDEWEB)
Y. Chen; A. Alexandru; S.J. Dong; T. Draper; I. Horvath; F.X. Lee; K.F. Liu; N. Mathur; C. Morningstar; M. Peardon; S. Tamhankar; B.L. Young; J.B. Zhang
2006-01-01
The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing ranging from 0.1fm - 0.2fm. These matrix elements are needed to predict the glueball branching ratios in J/{psi} radiative decays which will help identify the glueball states in experiments. Two types of improved local gluonic operators are constructed for a self-consistent check and the finite volume effects are studied. We find that lattice spacing dependence of our results is very weak and the continuum limits are reliably extrapolated, as a result of improvement of the lattice gauge action and local operators. We also give updated glueball masses with various quantum numbers.
A collocation finite element method with prior matrix condensation
International Nuclear Information System (INIS)
Sutcliffe, W.J.
1977-01-01
For thin shells with general loading, sixteen degrees of freedom have been used for a previous finite element solution procedure using a Collocation method instead of the usual variational based procedures. Although the number of elements required was relatively small, nevertheless the final matrix for the simultaneous solution of all unknowns could become large for a complex compound structure. The purpose of the present paper is to demonstrate a method of reducing the final matrix size, so allowing solution for large structures with comparatively small computer storage requirements while retaining the accuracy given by high order displacement functions. Collocation points, a number are equilibrium conditions which must be satisfied independently of the overall compatibility of forces and deflections for a complete structure. (Auth.)
Inert matrix fuel in dispersion type fuel elements
Energy Technology Data Exchange (ETDEWEB)
Savchenko, A.M. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation)]. E-mail: sav@bochvar.ru; Vatulin, A.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Morozov, A.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Sirotin, V.L. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Dobrikova, I.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Kulakov, G.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Ershov, S.A. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Kostomarov, V.P. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Stelyuk, Y.I. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation)
2006-06-30
The advantages of using inert matrix fuel (IMF) as a dispersion fuel in an aluminium alloy matrix are considered, in particular, low temperatures in the fuel centre, achievable high burn-ups, serviceability in transients and an environmentally friendly process of fuel rod fabrication. Two main versions of IMF are under development at A.A. Bochvar Institute, i.e. heterogeneous or isolated distribution of plutonium. The out-of-pile results on IMF loaded with uranium dioxide as plutonium simulator are presented. Fuel elements with uranium dioxide composition fabricated at A.A. Bochvar Institute are currently under MIR tests (RIAR, Dimitrovgrad). The fuel elements reached a burn-up of 88 MW d kg{sup -1} (equivalent to the burn up of the standard uranium dioxide pelletized fuel) without loss of leak-tightness of the cladding. The feasibility of fabricating IMF of these particular types with plutonium dioxide is considered with a view to in-pile irradiation.
Inert matrix fuel in dispersion type fuel elements
Savchenko, A. M.; Vatulin, A. V.; Morozov, A. V.; Sirotin, V. L.; Dobrikova, I. V.; Kulakov, G. V.; Ershov, S. A.; Kostomarov, V. P.; Stelyuk, Y. I.
2006-06-01
The advantages of using inert matrix fuel (IMF) as a dispersion fuel in an aluminium alloy matrix are considered, in particular, low temperatures in the fuel centre, achievable high burn-ups, serviceability in transients and an environmentally friendly process of fuel rod fabrication. Two main versions of IMF are under development at A.A. Bochvar Institute, i.e. heterogeneous or isolated distribution of plutonium. The out-of-pile results on IMF loaded with uranium dioxide as plutonium simulator are presented. Fuel elements with uranium dioxide composition fabricated at A.A. Bochvar Institute are currently under MIR tests (RIAR, Dimitrovgrad). The fuel elements reached a burn-up of 88 MW d kg-1 (equivalent to the burn up of the standard uranium dioxide pelletized fuel) without loss of leak-tightness of the cladding. The feasibility of fabricating IMF of these particular types with plutonium dioxide is considered with a view to in-pile irradiation.
Scattering-matrix elements of coated infinite-length cylinders
International Nuclear Information System (INIS)
Manickavasagam, S.; Menguec, M.P.
1998-01-01
The angular variations of scattering-matrix elements of coated cylindrical particles are presented. The sensitivity of different elements for a number of physical parameters are discussed, including size parameter, real and imaginary parts of the refractive index of the outer coat, and the inner core. The numerical predictions are presented for typical index-of-refraction values of cotton fibers. These results show that the physical structure of coated cylinders can be determined from carefully conducted light-scattering experiments. copyright 1998 Optical Society of America
The scattering matrix element of the three body reactive collision
International Nuclear Information System (INIS)
Morsy, M.W.; Hilal, A.A.; El-Sabagh, M.A.
1980-08-01
The optical model approximation has been applied to a previously derived set of coupled equations representing the dynamics of the three-body reactive scattering. The Schroedinger equation obtained describing the scattering problem has then been solved by inserting the effective mass approximation. The asymptotic requirements for both the entrance and exit channels, respectively, have been supplied to give the scattering matrix element of the reactive collision. (author)
Reweighting QCD matrix-element and parton-shower calculations
Energy Technology Data Exchange (ETDEWEB)
Bothmann, Enrico; Schumann, Steffen [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany); Schoenherr, Marek [Universitaet Zuerich, Physik-Institut, Zuerich (Switzerland)
2016-11-15
We present the implementation and validation of the techniques used to efficiently evaluate parametric and perturbative theoretical uncertainties in matrix-element plus parton-shower simulations within the Sherpa event-generator framework. By tracing the full α{sub s} and PDF dependences, including the parton-shower component, as well as the fixed-order scale uncertainties, we compute variational event weights on-the-fly, thereby greatly reducing the computational costs to obtain theoretical-uncertainty estimates. (orig.)
Double β-decay nuclear matrix elements and lepton conservation
International Nuclear Information System (INIS)
Vergados, J.D.
1976-01-01
The nuclear matrix elements involved in the double β-decay of 48 Ca, 130 Te, and 128 Te were calculated using realistic nuclear interactions and shell model nuclear wave functions. The double doorway state is not appreciably mixed in the ground state of the final nuclei. So the ground state transitions contain a small fraction of the sum rule. A lepton nonconservation parameter eta -4 was deduced
A stochastic method for computing hadronic matrix elements
Energy Technology Data Exchange (ETDEWEB)
Alexandrou, Constantia [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; The Cyprus Institute, Nicosia (Cyprus). Computational-based Science and Technology Research Center; Dinter, Simon; Drach, Vincent [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Jansen, Karl [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Hadjiyiannakou, Kyriakos [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Renner, Dru B. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Collaboration: European Twisted Mass Collaboration
2013-02-15
We present a stochastic method for the calculation of baryon three-point functions that is more versatile compared to the typically used sequential method. We analyze the scaling of the error of the stochastically evaluated three-point function with the lattice volume and find a favorable signal-to-noise ratio suggesting that our stochastic method can be used efficiently at large volumes to compute hadronic matrix elements.
Weak matrix elements efforts on the lattice: Status and prospects
International Nuclear Information System (INIS)
Soni, A.
1995-01-01
Lattice approach to weak matrix elements is reviewed. Recent progress in treating heavy quarks on the lattice is briefly discussed. Illustrative sample of results obtained so far is given. Among them I elaborate on B K , line-integral B and B → K* γ . Experimental implications especially with regard to constraints on the Standard Model (i.e. Wolfenstein) parameters, V td measurements and expectations for B s -bar B s , oscillations are briefly discussed
Rules for matrix element evaluations in JWKB approximation
International Nuclear Information System (INIS)
Giler, S.
1990-01-01
Using the properties of the so-called fundamental solutions to the one-dimensional Schroedinger equation having Froeman and Froeman form the rules are formulated which allow one to evaluate matrix elements in the JWKB approximation and its generalizations. The rules apply to operators M(x, d/dx), M being polynomial functions of their arguments. The applicability of the rules depends on the properties of the so-called canonical indices introduced in this paper. The canonical indices are global characteristics of underlying Stokes graphs. If sufficiently small in comparison with unity they allow one to apply safely the JWKB approximation within the so-called ε-reduced canonical domains of a given Stokes graph. The Oth canonical index for the nth energy level Stokes graph corresponding to the harmonic oscillator potential is found to be ε CAN = 0.678/(2n+1). If the application of the rules is allowed then approximated matrix elements are obtained in an unambiguous way and with an accuracy controlled by corresponding canonical indices. Several examples of matrix elements are considered to illustrate how the rules should be used. Limitations to the rules are also discussed with the aid of suitably chosen examples. (author)
Single-particle dispersion in compressible turbulence
Zhang, Qingqing; Xiao, Zuoli
2018-04-01
Single-particle dispersion statistics in compressible box turbulence are studied using direct numerical simulation. Focus is placed on the detailed discussion of effects of the particle Stokes number and turbulent Mach number, as well as the forcing type. When solenoidal forcing is adopted, it is found that the single-particle dispersion undergoes a transition from the ballistic regime at short times to the diffusive regime at long times, in agreement with Taylor's particle dispersion argument. The strongest dispersion of heavy particles is announced when the Stokes number is of order 1, which is similar to the scenario in incompressible turbulence. The dispersion tends to be suppressed as the Mach number increases. When hybrid solenoidal and compressive forcing at a ratio of 1/2 is employed, the flow field shows apparent anisotropic property, characterized by the appearance of large shock wave structures. Accordingly, the single-particle dispersion shows extremely different behavior from the solenoidal forcing case.
Dual color single particle tracking via nanobodies
International Nuclear Information System (INIS)
Albrecht, David; Winterflood, Christian M; Ewers, Helge
2015-01-01
Single particle tracking is a powerful tool to investigate the function of biological molecules by following their motion in space. However, the simultaneous tracking of two different species of molecules is still difficult to realize without compromising the length or density of trajectories, the localization accuracy or the simplicity of the assay. Here, we demonstrate a simple dual color single particle tracking assay using small, bright, high-affinity labeling via nanobodies of accessible targets with widely available instrumentation. We furthermore apply a ratiometric step-size analysis method to visualize differences in apparent membrane viscosity. (paper)
Hadronic matrix elements in the QCD on the lattice
International Nuclear Information System (INIS)
Altmeyer, R.
1995-01-01
The work describes a lattice simulation of full QCD with dynamical Kogut-Susskind fermions. We evaluated different hadronic matrix elements which are related to the static and low-energy behaviour of hadrons. The analysis was performed on a 16 3 x 24 lattice with a coupling constant of β = 5.35 and a quark mass of m = 0.010. The calculations are based on a set of 85 configurations created by using a Hybrid-Monte-Carlo algorithm. First we evaluated the mass and energy spectrum of the low-lying hadrons using local operators as well as non-local operators. As the complete spectrum of the different pion and ρ meson lattice representations has been calculated we were able to check the restoration of continuum flavor symmetry. Moreover, the determination of energies E of hadron states with non-vanishing momentum vector q made it possible to investigate the lattice dispersion function E( vector q). Another part of the presented work is the determination of mesonic decay constants which parameterise the weak decay of mesons. They are related to hadronic matrix elements of the respective quark currents and through the calculation of these matrix elements we were able to determine the decay constants f π and f ρ . Before doing so, we calculated non-perturbatively renormalization constants for the currents under consideration. The next part is the determination of hadronic coupling constants. These parameterise in an effective low-energy model the interactions of different hadrons. They are related to hadronic matrix elements whose lattice calculation can be dpme bu evaluating 3-point correlation functions. Thus we evaluted the hadronic coupling constants g ρππ and g NNπ . Finally, an investigation of the pion-nucleon σterm was done. The σterm is defined through a hadronic matrix element of a quark-antiquark operator and can thus be evaluated on the lattice via the calculation of a 3-point correlation function. As we determined the connected and the disconnected
Intermediate coupling collision strengths from LS coupled R-matrix elements
International Nuclear Information System (INIS)
Clark, R.E.H.
1978-01-01
Fine structure collision strength for transitions between two groups of states in intermediate coupling and with inclusion of configuration mixing are obtained from LS coupled reactance matrix elements (R-matrix elements) and a set of mixing coefficients. The LS coupled R-matrix elements are transformed to pair coupling using Wigner 6-j coefficients. From these pair coupled R-matrix elements together with a set of mixing coefficients, R-matrix elements are obtained which include the intermediate coupling and configuration mixing effects. Finally, from the latter R-matrix elements, collision strengths for fine structure transitions are computed (with inclusion of both intermediate coupling and configuration mixing). (Auth.)
Single-Particle Spin-Orbit Splittings in Nuclei
Kazuhiko, ANDO; Hiroharu, BANDO; Department of Physics, Kyoto University; Division of Mathematical Physics, Fukui University
1981-01-01
Single-particle spin-orbit splittings (Δ^) in ^O and ^Ca nuclei are evaluated within the framework of the effective interaction theory by employing the Reid soft-core potential and meson-exchange three-body forces (TBF). Among the two-body force contributions, the Pauli-rearrangement effect on Δ^ is studied with special care. The TBF contribution to Δ^ is found to be significant. The G-matrix, the second-order pauli-rearrangement and the TBF contribute to Δ^ by the amount of ～1/2, ～1/5 and ～1...
Projection operator treatment of single particle resonances
International Nuclear Information System (INIS)
Lev, A.; Beres, W.P.
1976-01-01
A projection operator method is used to obtain the energy and width of a single particle resonance. The resonance energy is found without scanning. An example of the first g/sub 9/2/ neutron resonance in 40 Ca is given and compared with the traditional phase shift method. The results of both approaches are quite similar. 4 figures
Calculations of hadronic weak matrix elements: A status report
International Nuclear Information System (INIS)
Sharpe, S.R.
1988-01-01
I review the calculations of hadronic matrix elements of the weak Hamiltonian. My major emphasis is on lattice calculations. I discuss the application to weak decay constants (f/sub K/, f/sub D/, f/sub B/), K 0 /minus/ /bar K/sup 0// and B 0 /minus/ /bar B/sup 0// mixing, K → ππ decays, and the CP violation parameters ε and ε'. I close with speculations on future progress. 57 refs., 4 figs., 2 tabs
Controlling inclusive cross sections in parton shower + matrix element merging
International Nuclear Information System (INIS)
Plaetzer, Simon
2012-11-01
We propose an extension of matrix element plus parton shower merging at tree level to preserve inclusive cross sections obtained from the merged and showered sample. Implementing this constraint generates approximate next-to-leading order (NLO) contributions similar to the LoopSim approach. We then show how full NLO, or in principle even higher order, corrections can be added consistently, including constraints on inclusive cross sections to account for yet missing parton shower accuracy at higher logarithmic order. We also show how NLO accuracy below the merging scale can be obtained.
Calculation of hadronic matrix elements using lattice QCD
International Nuclear Information System (INIS)
Gupta, R.
1993-01-01
The author gives a brief introduction to the scope of lattice QCD calculations in his effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First the author discusses the extraction of CKM matrix elements from measurements of form factors for semileptonic decays of heavy-light pseudoscalar mesons such as D → Keν. Second, he presents the status of results for the kaon B parameter relevant to CP violation. He concludes the talk with a short outline of his experiences with optimizing QCD codes on the CM5
Controlling inclusive cross sections in parton shower + matrix element merging
Energy Technology Data Exchange (ETDEWEB)
Plaetzer, Simon
2012-11-15
We propose an extension of matrix element plus parton shower merging at tree level to preserve inclusive cross sections obtained from the merged and showered sample. Implementing this constraint generates approximate next-to-leading order (NLO) contributions similar to the LoopSim approach. We then show how full NLO, or in principle even higher order, corrections can be added consistently, including constraints on inclusive cross sections to account for yet missing parton shower accuracy at higher logarithmic order. We also show how NLO accuracy below the merging scale can be obtained.
Something different - caching applied to calculation of impedance matrix elements
CSIR Research Space (South Africa)
Lysko, AA
2012-09-01
Full Text Available of the multipliers, the approximating functions are used any required parameters, such as input impedance or gain pattern etc. The method is relatively straightforward but, especially for small to medium matrices, requires spending time on filling... of the computing the impedance matrix for the method of moments, or a similar method, such as boundary element method (BEM) [22], with the help of the flowchart shown in Figure 1. Input Parameters (a) Search the cached data for a match (b) A match found...
Calculation of hadronic matrix elements using lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Gupta, R.
1993-08-01
The author gives a brief introduction to the scope of lattice QCD calculations in his effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First the author discusses the extraction of CKM matrix elements from measurements of form factors for semileptonic decays of heavy-light pseudoscalar mesons such as D {yields} Ke{nu}. Second, he presents the status of results for the kaon B parameter relevant to CP violation. He concludes the talk with a short outline of his experiences with optimizing QCD codes on the CM5.
Improved determination of hadron matrix elements using the variational method
International Nuclear Information System (INIS)
Dragos, J.; Kamleh, W.; Leinweber, D.B.; Zanotti, J.M.; Rakow, P.E.L.; Young, R.D.; Adelaide Univ.
2015-11-01
The extraction of hadron form factors in lattice QCD using the standard two- and three-point correlator functions has its limitations. One of the most commonly studied sources of systematic error is excited state contamination, which occurs when correlators are contaminated with results from higher energy excitations. We apply the variational method to calculate the axial vector current g A and compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.
Representation of the Coulomb Matrix Elements by Means of Appell Hypergeometric Function F 2
Bentalha, Zine el abidine
2018-06-01
Exact analytical representation for the Coulomb matrix elements by means of Appell's double series F 2 is derived. The finite sum obtained for the Appell function F 2 allows us to evaluate explicitly the matrix elements of the two-body Coulomb interaction in the lowest Landau level. An application requiring the matrix elements of Coulomb potential in quantum Hall effect regime is presented.
Measurement of the CKM matrix element |V_ts|²
Unverdorben, Christopher Gerhard
This is the first direct measurement of the CKM matrix element |V_ts|, using data collected by the ATLAS detector in 2012 at √s=8 TeV pp-collisions with a total integrated luminosity of 20.3 fb⁻¹. The analysis is based on 112171 reconstructed tt̅ candidate events in the lepton+jets channel, having a purity of 90.0 %. 183 tt̅→WWbs̅ decays are expected (charge conjugation implied), which are available for the extraction of the CKM matrix element |V_ts|². To identify these rare decays, several observables are examined, such as the properties of jets, tracks and of b-quark identification algorithms. Furthermore, the s-quark hadrons K0s are considered, reconstructed by a kinematic fit. The best observables are combined in a multivariate analysis, called "boosted decision trees". The responses from Monte Carlo simulations are used as templates for a fit to data events yielding a significance value of 0.7σ for t→s+W decays. An upper limit of |V_ts|² < 1.74 % at 95 % confidence level is set, includi...
The current matrix elements from HAL QCD method
Watanabe, Kai; Ishii, Noriyoshi
2018-03-01
HAL QCD method is a method to construct a potential (HAL QCD potential) that reproduces the NN scattering phase shift faithful to the QCD. The HAL QCD potential is obtained from QCD by eliminating the degrees of freedom of quarks and gluons and leaving only two particular hadrons. Therefor, in the effective quantum mechanics of two nucleons defined by HAL QCD potential, the conserved current consists not only of the nucleon current but also an extra current originating from the potential (two-body current). Though the form of the two-body current is closely related to the potential, it is not straight forward to extract the former from the latter. In this work, we derive the the current matrix element formula in the quantum mechanics defined by the HAL QCD potential. As a first step, we focus on the non-relativistic case. To give an explicit example, we consider a second quantized non-relativistic two-channel coupling model which we refer to as the original model. From the original model, the HAL QCD potential for the open channel is constructed by eliminating the closed channel in the elastic two-particle scattering region. The current matrix element formula is derived by demanding the effective quantum mechanics defined by the HAL QCD potential to respond to the external field in the same way as the original two-channel coupling model.
Single-particle Schroedinger fluid. I. Formulation
International Nuclear Information System (INIS)
Kan, K.K.; Griffin, J.J.
1976-01-01
The problem of a single quantal particle moving in a time-dependent external potential well is formulated specifically to emphasize and develop the fluid dynamical aspects of the matter flow. This idealized problem, the single-particle Schroedinger fluid, is shown to exhibit already a remarkably rich variety of fluid dynamical features, including compressible flow and line vortices. It provides also a sufficient framework to encompass simultaneously various simplified fluidic models for nuclei which have earlier been postulated on an ad hoc basis, and to illuminate their underlying restrictions. Explicit solutions of the single-particle Schroedinger fluid problem are studied in the adiabatic limit for their mathematical and physical implications (especially regarding the collective kinetic energy). The basic generalizations for extension of the treatment to the many-body Schroedinger fluid are set forth
Matching Matrix Elements and Parton Showers with HERWIG and PYTHIA
Mrenna, S; Mrenna, Stephen; Richardson, Peter
2004-01-01
We report on our exploration of matching matrix element calculations with the parton-shower models contained in the event generators HERWIG and Pythia. We describe results for e+e- collisions and for the hadroproduction of W bosons and Drell--Yan pairs. We compare methods based on (1) a strict implementation of ideas proposed by Catani, et al., (2) a generalization based on using the internal Sudakov form factors of HERWIG and Pythia, and (3) a simpler proposal of M. Mangano. Where appropriate, we show the dependence on various choices of scales and clustering that do not affect the soft and collinear limits of the predictions, but have phenomenological implications. Finally, we comment on how to use these results to state systematic errors on the theoretical predictions.
Neutrinoless Double Beta Decay Matrix Elements in Light Nuclei
Energy Technology Data Exchange (ETDEWEB)
Pastore, S.; Carlson, J.; Cirigliano, V.; Dekens, W.; Mereghetti, E.; Wiringa, R. B.
2018-01-17
We present the first ab initio calculations of neutrinoless double-β decay matrix elements in A=6-12 nuclei using variational Monte Carlo wave functions obtained from the Argonne v_{18} two-nucleon potential and Illinois-7 three-nucleon interaction. We study both light Majorana neutrino exchange and potentials arising from a large class of multi-TeV mechanisms of lepton-number violation. Our results provide benchmarks to be used in testing many-body methods that can be extended to the heavy nuclei of experimental interest. In light nuclei we also study the impact of two-body short-range correlations and the use of different forms for the transition operators, such as those corresponding to different orders in chiral effective theory.
Measurements of the CKM matrix element V(cb)
Di Ciaccio, L
1996-01-01
A review of the measurements of the element V ch of the CabibboKobayashi-Maskawa matrix is presented. The experimental results discussed here are based on the selection of the decays B -t D' lv and on the study of the differential decay rate as a function of the momentum transfer from the B to D' particle. This method allows to measure IV chi with a reduced model dependence. This review describes mainly the most recent analyses which have been performed by the LEP Collaborations. The IVcbl determination based on the inclusive semileptonic decay width of the B hadrons is also shortly presented. The results obtained with these two methods are averaged and prospects for the future are discussed
Generalized hypervirial and Blanchard's recurrence relations for radial matrix elements
International Nuclear Information System (INIS)
Dong Shihai; Chen Changyuan; Lozada-Cassou, M
2005-01-01
Based on the Hamiltonian identity, we propose a generalized expression of the second hypervirial for an arbitrary central potential wavefunction in arbitrary dimensions D. We demonstrate that the new proposed second hypervirial formula is very powerful in deriving the general Blanchard's and Kramers' recurrence relations among the radial matrix elements. As their useful and important applications, we derive all general Blanchard's and Kramers' recurrence relations and some identities for the Coulomb-like potential, harmonic oscillator and Kratzer oscillator. The recurrence relation and identity between the exponential functions and the powers of the radial function are established for the Morse potential. The corresponding general Blanchard's and Kramers' recurrence relations in 2D are also briefly studied
Anatomy of double beta decay nuclear matrix elements
Energy Technology Data Exchange (ETDEWEB)
Vogel, Petr, E-mail: pxv@caltech.ed [Kellogg Radiation Laboratory 106-38 Caltech. Pasadena, CA 91125 (United States)
2009-06-01
The necessary ingredients for a realistic evaluation of the 0vbetabeta nuclear matrix elements are reviewed. It is argued that the short range nucleon correlations, nucleon finite size, and higher order nuclear currents need to be included in the calculation, even though a consensus on the best way to treat all of these effects has not been reached. Another positive development is the realization that the two alternative and complementary methods, the Quasiparticle Random Phase Approximation and the Nuclear Shell Model, agree on many aspects of the calculation, in particular on the competition, or cancelation, between the contribution of nuclear pairing on one hand, and the other pieces of interaction that result in admixtures of broken pairs or higher seniority states on the other hand. The relatively short range (r <= 2-3 fm) of the effective 0vbetabeta operator found in both methods is a consequence of that competition.
Matrix elements of the relativistic electron-transition operators
International Nuclear Information System (INIS)
Rudzikas, Z.B.; Slepcov, A.A.; Kickin, I.S.
1976-01-01
The formulas, which enable us to calculate the electric and magnetic multipole transition probabilities in relativistic approximation under various gauge conditions of the electromagnetic potential, are presented. The numerical values of the coefficients of the one-electron reduced matrix elements of the relativistic operators of the electric and magnetic dipole transitions between the configurations K 0 n 2 l 2 j 2 α 0 J 0 j 2 J--K 0 n 1 l 1 j 1 α 0 'J 0 'j 1 J', where K 0 represents any electronic configuration, having the quantum number of the total angular momentum 0 less than or equal to J 0 less than or equal to 8 (the step is 1 / 2 ), and 1 / 2 less than or equal to j 2 , j 1 less than or equal to 7 / 2 , are given
Single-Particle States in $^{133}$Sn
Huck, A
2002-01-01
% IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.
Damping of unbound single-particle modes
International Nuclear Information System (INIS)
Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.
1995-07-01
The (α, 3 He-n) reaction has been investigated at 120 MeV incident energy on 64 Ni, 90 Zr and 120 Sn target nuclei. Neutrons in coincidence with 3 He particles emitted at 0 deg were detected, in order to get information about the decay of single-particle states embedded in the (α, 3 He) continuum. Neutron angular correlations, multiplicity values and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Direct branching ratios in 91 Zr deduced from this analysis are compared with the predictions of two nuclear structure models. (author)
Fabrication of synthetic diffractive elements using advanced matrix laser lithography
International Nuclear Information System (INIS)
Škeren, M; Svoboda, J; Kveton, M; Fiala, P
2013-01-01
In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ∼ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.
Fabrication of synthetic diffractive elements using advanced matrix laser lithography
Škereň, M.; Svoboda, J.; Květoň, M.; Fiala, P.
2013-02-01
In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ~ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.
Theory of the particle matrix elements for Helium atom scattering in surfaces
International Nuclear Information System (INIS)
Khater, A.; Toennies, J.P.
2000-01-01
Full text.A brief review is presented for the recent development of the theory of the particle transition matrix elements, basic to the cross section for Helium and inert particle scattering at thermal energies in solid surfaces. the Jackson and Mott matrix elements are presented and discussed for surface scattering processes, habitually classified as elastic and inelastic. Modified transition matrix elements, introduced originally to account for the cut-off effects, are presented in a direct and simple manner. the Debye-Waller factor is introduced and discussed. A recent calculation for the particle transition matrix elements is presented for the specular and inelastic transition matrix elements and the corresponding inelastic scattering cross section is compared in detail to experimental data. the specular and inelastic transition matrix elements are found to be intrinsically similar owing to the intermediate role of a proposed virtual particle squeezed state near the surface
Controlling excited-state contamination in nucleon matrix elements
Energy Technology Data Exchange (ETDEWEB)
Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; Engelhardt, Michael; Green, Jeremy; Joó, Bálint; Lin, Huey-Wen; Negele, John; Orginos, Kostas; Pochinsky, Andrew; Richards, David; Syritsyn, Sergey; Winter, Frank
2016-06-01
We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1 flavor ensemble with lattices of size $32^3 \\times 64$ generated using the rational hybrid Monte Carlo algorithm at $a=0.081$~fm and with $M_\\pi=312$~MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a two-state fit to data at multiple values of the source-sink separation $t_{\\rm sep}$. We show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost-effectiveness. A detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of $t_{\\rm sep}$ needed to demonstrate convergence of the isovector charges of the nucleon to the $t_{\\rm sep} \\to \\infty $ estimates is presented.
Damping of unbound single-particle modes
International Nuclear Information System (INIS)
Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A.
1995-01-01
The (α, 3 He-n) reaction has been investigated at 120 MeV incident energy on 64 Ni, 90 Zr, and 120 Sn target nuclei. Neutrons in coincidence with 3 He particles emitted at 0 degree were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the (α, 3 He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in 91 Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the (α, 3 He) continuum are shown to be mainly statistical
Freeman, S. J.; Sharp, D. K.; McAllister, S. A.; Kay, B. P.; Deibel, C. M.; Faestermann, T.; Hertenberger, R.; Mitchell, A. J.; Schiffer, J. P.; Szwec, S. V.; Thomas, J. S.; Wirth, H.-F.
2017-11-01
The rearrangements of protons and neutrons amongst the valence single-particle orbitals during double-β decay of 100Mo have been determined by measuring cross sections in (d ,p ), (p ,d ), (3He,α ), and (3He,d ) reactions on Mo,10098 and Ru,102100 targets. The deduced nucleon occupancies reveal significant discrepancies when compared with theoretical calculations; the same calculations have previously been used to determine the nuclear matrix element associated with the decay probability of double-β decay of the 100Mo system.
Gamow-Teller matrix elements from 00 ( p,n) cross section
International Nuclear Information System (INIS)
Goodman, C.D.; Goulding, C.A.; Greenfield, M.B.; Rapaport, J.; Bainum, D.E.; Foster, C.C.; Love, W.G.; Petrovich, F.
1980-01-01
After simple corrections for distortion effects, 120-MeV, 0 0 (p,n) cross sections are found to be proportional to the squares of the corresponding Fermi and Gamow-Teller matrix elements extracted from β-decay measurements. It is suggested that this proportionality can be used to extract Gamow-Teller matrix elements for transitions inaccessible to β decay
Bag-model matrix elements of the parity-violating weak hamiltonian for charmed baryons
International Nuclear Information System (INIS)
Ebert, D.; Kallies, W.
1983-01-01
Baryon matrix elements of the parity-violating part of the charmchanging weak Hamiltonian might be significant and comparable with those of the parity-conserving one due to large symmetry breaking. Expression for these new matrix elements by using the MIT-bag model are derived and their implications on earlier calculations of nonleptonic charmed-baryon decays are estimated
The temporal Fresnel number in terms of ray matrix elements
International Nuclear Information System (INIS)
Zhang Zhuhong; Fan Dianyuan
1993-01-01
By using the analogy between temporal ray matrix and the well known ray matrix, the temporal Fresnel number, which gives the qualitative and quasiquantitative characteristics (shape, width and chirp) of optical pulses, is derived. A concept of effective propagation time is introduced. Several typical examples are discussed. 6 refs
Damping of unbound single-particle modes
Energy Technology Data Exchange (ETDEWEB)
Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A. [Institut de Physique Nucleaire, IN2P3-CNRS, 91406 Orsay Cedex (France)]|[Kernfysisch Versneller Instituut, 9747 AA Groningen (Netherlands)]|[Nuclear Research Institute, Debrecen P.O. Box 51, H-4001 (Hungary)]|[NSCL, Michigan State University, East Lansing, Michigan 48824 (United States)]|[Dep. Fisica, Fac. Cs. Exactas, UNLP, CC Nio 67, 1900 La Plata (Argentina)]|[Institut de Sciences Exactes,Universite de Tizi-Ouzou, 15000 Tizi-Ouzou (Algeria)
1995-11-01
The ({alpha},{sup 3}He-{ital n}) reaction has been investigated at 120 MeV incident energy on {sup 64}Ni, {sup 90}Zr, and {sup 120}Sn target nuclei. Neutrons in coincidence with {sup 3}He particles emitted at 0{degree} were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the ({alpha},{sup 3}He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in {sup 91}Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the ({alpha},{sup 3}He) continuum are shown to be mainly statistical.
Microscopic calculations of λ single particle energies
International Nuclear Information System (INIS)
Usmani, Q. N.
1998-01-01
Λ binding energy data for total baryon number A ≤ 208 and for Λ angular momenta ell Λ ≤ 3 are analyzed in terms of phenomenological (but generally consistent with meson-exchange) ΛN and ΛNN potentials. The Fermi-Hypernetted-Chain technique is used to calculate the expectation values for the Λ binding to nuclear matter. Accurate effective ΛN and ΛNN potentials are obtained which are folded with the core nucleus nucleon densities to calculate the Λ single particle potential U Λ (r). We use a dispersive ΛNN potential but also include an explicit ρ dependence to allow for reduced repulsion in the surface, and the best fits have a large ρ dependence giving consistency with the variational Monte Carlo calculations for Λ 5 He. The exchange fraction of the ΛN space-exchange potential is found to be 0.2-0.3 corresponding to m Λ * ≅ (0.74-0.82)m Λ . Charge symmetry breaking is found to be significant for heavy hypernuclei with a large neutron excess, with a strength consistent with that obtained from the A = 4 hypernuclei
Single-particle stochastic heat engine
Rana, Shubhashis; Pal, P. S.; Saha, Arnab; Jayannavar, A. M.
2014-10-01
We have performed an extensive analysis of a single-particle stochastic heat engine constructed by manipulating a Brownian particle in a time-dependent harmonic potential. The cycle consists of two isothermal steps at different temperatures and two adiabatic steps similar to that of a Carnot engine. The engine shows qualitative differences in inertial and overdamped regimes. All the thermodynamic quantities, including efficiency, exhibit strong fluctuations in a time periodic steady state. The fluctuations of stochastic efficiency dominate over the mean values even in the quasistatic regime. Interestingly, our system acts as an engine provided the temperature difference between the two reservoirs is greater than a finite critical value which in turn depends on the cycle time and other system parameters. This is supported by our analytical results carried out in the quasistatic regime. Our system works more reliably as an engine for large cycle times. By studying various model systems, we observe that the operational characteristics are model dependent. Our results clearly rule out any universal relation between efficiency at maximum power and temperature of the baths. We have also verified fluctuation relations for heat engines in time periodic steady state.
Single particle level scheme for alpha decay
International Nuclear Information System (INIS)
Mirea, M.
1998-01-01
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 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)
International Nuclear Information System (INIS)
Gregersen, A.W.
1977-01-01
A comparison is made between matrix elements calculated using the uncoupled channel Sussex approach to second order in DWBA and matrix elements calculated using a square well potential. The square well potential illustrated the problem of the determining parameter independence balanced with the concept of phase shift difference. The super-soft core potential was used to discuss the systematics of the Sussex approach as a function of angular momentum as well as the relation between Sussex generated and effective interaction matrix elements. In the uncoupled channels the original Sussex method of extracting effective interaction matrix elements was found to be satisfactory. In the coupled channels emphasis was placed upon the 3 S 1 -- 3 D 1 coupled channel matrix elements. Comparison is made between exactly calculated matrix elements, and matrix elements derived using an extended formulation of the coupled channel Sussex method. For simplicity the potential used is a nonseparable cut-off oscillator. The eigenphases of this potential can be made to approximate the realistic nucleon--nucleon phase shifts at low energies. By using the cut-off oscillator test potential, the original coupled channel Sussex method of determining parameter independence was shown to be incapable of accurately reproducing the exact cut-off oscillator matrix elements. The extended Sussex method was found to be accurate to within 10 percent. The extended method is based upon more general coupled channel DWBA and a noninfinite oscillator wave function solution to the cut-off oscillator auxiliary potential. A comparison is made in the coupled channels between matrix elements generated using the original Sussex method and the extended method. Tables of matrix elements generated using the original uncoupled channel Sussex method and the extended coupled channel Sussex method are presented for all necessary angular momentum channels
QCD event generators with next-to-leading order matrix-elements and parton showers
International Nuclear Information System (INIS)
Kurihara, Y.; Fujimoto, J.; Ishikawa, T.; Kato, K.; Kawabata, S.; Munehisa, T.; Tanaka, H.
2003-01-01
A new method to construct event-generators based on next-to-leading order QCD matrix-elements and leading-logarithmic parton showers is proposed. Matrix elements of loop diagram as well as those of a tree level can be generated using an automatic system. A soft/collinear singularity is treated using a leading-log subtraction method. Higher order resummation of the soft/collinear correction by the parton shower method is combined with the NLO matrix-element without any double-counting in this method. An example of the event generator for Drell-Yan process is given for demonstrating a validity of this method
Hadron matrix elements of quark operators in the relativistic quark model, 2. Model calculation
Energy Technology Data Exchange (ETDEWEB)
Arisue, H; Bando, M; Toya, M [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, H
1979-11-01
Phenomenological studies of the matrix elements of two- and four-quark operators are made on the basis of relativistic independent quark model for typical three cases of the potentials: rigid wall, linearly rising and Coulomb-like potentials. The values of the matrix elements of two-quark operators are relatively well reproduced in each case, but those of four-quark operators prove to be too small in the independent particle treatment. It is suggested that the short-range two-quark correlations must be taken into account in order to improve the values of the matrix elements of the four-quark operators.
Hadron matrix elements of quark operators in the relativistic quark model
Energy Technology Data Exchange (ETDEWEB)
Bando, Masako; Toya, Mihoko [Kyoto Univ. (Japan). Dept. of Physics; Sugimoto, Hiroshi
1979-07-01
General formulae for evaluating matrix elements of two- and four-quark operators sandwiched by one-hadron states are presented on the basis of the relativistic quark model. Observed hadronic quantities are expressed in terms of those matrix elements of two- and four-quark operators. One observes various type of relativistic expression for the matrix elements which in the non-relativistic case reduce to simple expression of the so-called ''the wave function at the origin /sup +/psi(0)/sup +/''.
Automated data collection in single particle electron microscopy
Tan, Yong Zi; Cheng, Anchi; Potter, Clinton S.; Carragher, Bridget
2016-01-01
Automated data collection is an integral part of modern workflows in single particle electron microscopy (EM) research. This review surveys the software packages available for automated single particle EM data collection. The degree of automation at each stage of data collection is evaluated, and the capabilities of the software packages are described. Finally, future trends in automation are discussed. PMID:26671944
Single particle irradiation effect of digital signal processor
International Nuclear Information System (INIS)
Fan Si'an; Chen Kenan
2010-01-01
The single particle irradiation effect of high energy neutron on digital signal processor TMS320P25 in dynamic working condition has been studied. The influence of the single particle on the device has been explored through the acquired waveform and working current of TMS320P25. Analysis results, test data and test methods have also been presented. (authors)
Radial Matrix Elements of Hydrogen Atom and the Correspondence ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Hydrogen excited states—radial matrix element—corres- ... atoms, its availability, production, its spectras, and importance in astrophysics (Dupree ... far away revolving lazily around in a slow orbit like a distant planet in the solar system. As the electron orbit diameter grows rapidly, its energy also decreases rapidly. Currently ...
Matrix elements of a hyperbolic vector operator under SO(2,1)
International Nuclear Information System (INIS)
Zettili, N.; Boukahil, A.
2003-01-01
We deal here with the use of Wigner–Eckart type arguments to calculate the matrix elements of a hyperbolic vector operator V-vector by expressing them in terms of reduced matrix elements. In particular, we focus on calculating the matrix elements of this vector operator within the basis of the hyperbolic angular momentum T-vector whose components T-vector 1 , T-vector 2 , T-vector 3 satisfy an SO(2,1) Lie algebra. We show that the commutation rules between the components of V-vector and T-vector can be inferred from the algebra of ordinary angular momentum. We then show that, by analogy to the Wigner–Eckart theorem, we can calculate the matrix elements of V-vector within a representation where T-vector 2 and T-vector 3 are jointly diagonal. (author)
Program package for calculating matrix elements of two-cluster structures in nuclei
International Nuclear Information System (INIS)
Krivec, R.; Mihailovic, M.V.; Kernforschungszentrum Karlsruhe G.m.b.H.
1982-01-01
Matrix elements of operators between Slater determinants of two-cluster structures must be expanded into partial waves for the purpose of angular momentum projection. The expansion coefficients contain integrals over the spherical angles theta and phi. (orig.)
3-Loop massive O(T2F) contributions to the DIS operator matrix element Agg
International Nuclear Information System (INIS)
Ablinger, J.; Schneider, C.; Bluemlein, J.; Freitas, A. de; Hasselhuhn, A.; Round, M.; Manteuffel, A. von
2014-09-01
Contributions to heavy flavour transition matrix elements in the variable flavour number scheme are considered at 3-loop order. In particular a calculation of the diagrams with two equal masses that contribute to the massive operator matrix element A (3) gg,Q is performed. In the Mellin space result one finds finite nested binomial sums. In x-space these sums correspond to iterated integrals over an alphabet containing also square-root valued letters.
Institute of Scientific and Technical Information of China (English)
XU Xiu-Wei; REN Ting-Qi; LIU Shu-Yan; MA Qiu-Ming; LIU Sheng-Dian
2007-01-01
Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's), we present the analytic expression of arbitrary matrix elements for BEQPO's. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO's.
Matrix elements of u and p for the modified Poeschl-Teller potential
International Nuclear Information System (INIS)
Gomez-Camacho, J; Lemus, R; Arias, J M
2004-01-01
Closed analytical expressions in terms of a single sum are obtained for the matrix elements of the momentum and the natural variable u tanh(αx) in the basis of the modified Poeschl-Teller (MPT) bound eigenstates. These matrix elements are first expressed in terms of Franck-Condon factors, which thereafter are substituted for analytic expressions. Expansions of the variables p and u in terms of creation and annihilation operators associated with the MPT bound eigenfunctions are also presented
A pedagogical derivation of the matrix element method in particle physics data analysis
Sumowidagdo, Suharyo
2018-03-01
The matrix element method provides a direct connection between the underlying theory of particle physics processes and detector-level physical observables. I am presenting a pedagogically-oriented derivation of the matrix element method, drawing from elementary concepts in probability theory, statistics, and the process of experimental measurements. The level of treatment should be suitable for beginning research student in phenomenology and experimental high energy physics.
Directory of Open Access Journals (Sweden)
Romanas Karkauskas
2011-04-01
Full Text Available The expressions of the finite element method tangent stiffness matrix of geometrically nonlinear constructions are not fully presented in publications. The matrixes of small displacements stiffness are usually presented only. To solve various problems of construction analysis or design and to specify the mode of the real deflection of construction, it is necessary to have a fully described tangent matrix analytical expression. This paper presents a technique of tangent stiffness matrix generation using discrete body total potential energy stationary conditions considering geometrically nonlinear 2D frame element taking account of interelement interaction forces only. The obtained vector-function derivative of internal forces considering nodal displacements is the tangent stiffness matrix. The analytical expressions having nodal displacements of matrixes forming the content of the 2D frame construction element tangent stiffness matrix are presented in the article. The suggested methodology has been checked making symbolical calculations in the medium of MatLAB calculation complex. The analytical expression of the stiffness matrix has been obtained.Article in Lithuanian
On the generalized eigenvalue method for energies and matrix elements in lattice field theory
Energy Technology Data Exchange (ETDEWEB)
Blossier, Benoit [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Paris-XI Univ., 91 - Orsay (France). Lab. de Physique Theorique; Morte, Michele della [CERN, Geneva (Switzerland). Physics Dept.]|[Mainz Univ. (Germany). Inst. fuer Kernphysik; Hippel, Georg von; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Mendes, Tereza [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Sao Paulo Univ. (Brazil). IFSC
2009-02-15
We discuss the generalized eigenvalue problem for computing energies and matrix elements in lattice gauge theory, including effective theories such as HQET. It is analyzed how the extracted effective energies and matrix elements converge when the time separations are made large. This suggests a particularly efficient application of the method for which we can prove that corrections vanish asymptotically as exp(-(E{sub N+1}-E{sub n}) t). The gap E{sub N+1}-E{sub n} can be made large by increasing the number N of interpolating fields in the correlation matrix. We also show how excited state matrix elements can be extracted such that contaminations from all other states disappear exponentially in time. As a demonstration we present numerical results for the extraction of ground state and excited B-meson masses and decay constants in static approximation and to order 1/m{sub b} in HQET. (orig.)
On the generalized eigenvalue method for energies and matrix elements in lattice field theory
International Nuclear Information System (INIS)
Blossier, Benoit; Mendes, Tereza; Sao Paulo Univ.
2009-02-01
We discuss the generalized eigenvalue problem for computing energies and matrix elements in lattice gauge theory, including effective theories such as HQET. It is analyzed how the extracted effective energies and matrix elements converge when the time separations are made large. This suggests a particularly efficient application of the method for which we can prove that corrections vanish asymptotically as exp(-(E N+1 -E n ) t). The gap E N+1 -E n can be made large by increasing the number N of interpolating fields in the correlation matrix. We also show how excited state matrix elements can be extracted such that contaminations from all other states disappear exponentially in time. As a demonstration we present numerical results for the extraction of ground state and excited B-meson masses and decay constants in static approximation and to order 1/m b in HQET. (orig.)
Matrix elements of Δ B =0 operators in heavy hadron chiral perturbation theory
Lee, Jong-Wan
2015-05-01
We study the light-quark mass and spatial volume dependence of the matrix elements of Δ B =0 four-quark operators relevant for the determination of Vu b and the lifetime ratios of single-b hadrons. To this end, one-loop diagrams are computed in the framework of heavy hadron chiral perturbation theory with partially quenched formalism for three light-quark flavors in the isospin limit; flavor-connected and -disconnected diagrams are carefully analyzed. These calculations include the leading light-quark flavor and heavy-quark spin symmetry breaking effects in the heavy hadron spectrum. Our results can be used in the chiral extrapolation of lattice calculations of the matrix elements to the physical light-quark masses and to infinite volume. To provide insight on such chiral extrapolation, we evaluate the one-loop contributions to the matrix elements containing external Bd, Bs mesons and Λb baryon in the QCD limit, where sea and valence quark masses become equal. In particular, we find that the matrix elements of the λ3 flavor-octet operators with an external Bd meson receive the contributions solely from connected diagrams in which current lattice techniques are capable of precise determination of the matrix elements. Finite volume effects are at most a few percent for typical lattice sizes and pion masses.
Correlation between eigenvalues and sorted diagonal matrix elements of a large dimensional matrix
International Nuclear Information System (INIS)
Arima, A.
2008-01-01
Functional dependences of eigenvalues as functions of sorted diagonal elements are given for realistic nuclear shell model (NSM) hamiltonian, the uniform distribution hamiltonian and the GOE hamiltonian. In the NSM case, the dependence is found to be linear. We discuss extrapolation methods for more accurate predictions for low-lying states. (author)
Quasi-exact evaluation of time domain MFIE MOT matrix elements
Shi, Yifei
2013-07-01
A previously proposed quasi-exact scheme for evaluating matrix elements resulting from the marching-on-in-time (MOT) discretization of the time domain electric field integral equation (EFIE) is extended to matrix entries resulting from the discretization of its magnetic field integral equation (MFIE) counterpart. Numerical results demonstrate the accuracy of the scheme as well as the late-time stability of the resulting MOT-MFIE solver. © 2013 IEEE.
Quasi-exact evaluation of time domain MFIE MOT matrix elements
Shi, Yifei; Bagci, Hakan; Shanker, Balasubramaniam; Lu, Mingyu; Michielssen, Eric
2013-01-01
A previously proposed quasi-exact scheme for evaluating matrix elements resulting from the marching-on-in-time (MOT) discretization of the time domain electric field integral equation (EFIE) is extended to matrix entries resulting from the discretization of its magnetic field integral equation (MFIE) counterpart. Numerical results demonstrate the accuracy of the scheme as well as the late-time stability of the resulting MOT-MFIE solver. © 2013 IEEE.
Method of computer algebraic calculation of the matrix elements in the second quantization language
International Nuclear Information System (INIS)
Gotoh, Masashi; Mori, Kazuhide; Itoh, Reikichi
1995-01-01
An automated method by the algebraic programming language REDUCE3 for specifying the matrix elements expressed in second quantization language is presented and then applied to the case of the matrix elements in the TDHF theory. This program works in a very straightforward way by commuting the electron creation and annihilation operator (a † and a) until these operators have completely vanished from the expression of the matrix element under the appropriate elimination conditions. An improved method using singlet generators of unitary transformations in the place of the electron creation and annihilation operators is also presented. This improvement reduces the time and memory required for the calculation. These methods will make programming in the field of quantum chemistry much easier. 11 refs., 1 tab
Calculation of the Cholesky factor directly from the stiffness matrix of the structural element
International Nuclear Information System (INIS)
Prates, C.L.M.; Soriano, H.L.
1978-01-01
The analysis of the structures of nuclear power plants requires the evaluation of the internal forces. This is attained by the solution of a system of equations. This solution takes most of the computing time and memory. One of the ways it can be achieved is based on the Cholesky factor. The structural matrix of the coeficients is transformed into an upper triangular matrix by the Cholesky decomposition. Cholesky factor can be obtained directly from the stiffness matrix of the structural element. The result can thus be obtained in a more precise and quick way. (Author)
Calculating Relativistic Transition Matrix Elements for Hydrogenic Atoms Using Monte Carlo Methods
Alexander, Steven; Coldwell, R. L.
2015-03-01
The nonrelativistic transition matrix elements for hydrogen atoms can be computed exactly and these expressions are given in a number of classic textbooks. The relativistic counterparts of these equations can also be computed exactly but these expressions have been described in only a few places in the literature. In part, this is because the relativistic equations lack the elegant simplicity of the nonrelativistic equations. In this poster I will describe how variational Monte Carlo methods can be used to calculate the energy and properties of relativistic hydrogen atoms and how the wavefunctions for these systems can be used to calculate transition matrix elements.
Axial-Current Matrix Elements in Light Nuclei from Lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Savage, Martin [Univ. of Washington, Seattle, WA (United States); Shanahan, Phiala E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Tiburzi, Brian C. [Univ. of Maryland, College Park, MD (United States); Wagman, Michael L. [Univ. of Washington, Seattle, WA (United States); Winter, Frank T. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Beane, Silas [Univ. of New Hampshire, Durham, NH (United States); Chang, Emmanuel [Univ. of Washington, Seattle, WA (United States); Davoudi, Zohreh; Detmold, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States)
2016-12-01
I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\\beta\\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.
The two-mass contribution to the three-loop pure singlet operator matrix element
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2017-11-15
We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function F{sub 2}(x,Q{sup 2}) at O(α{sup 3}{sub s}) as well as for the matching relations in the variable flavor number scheme and the heavy quark distribution functions at the same order. The result for the operator matrix element is given in terms of generalized iterated integrals that include square root letters in the alphabet, depending also on the mass ratio through the main argument. Numerical results are presented.
Matrix elements of Yale potential and level properties of light nuclei
Energy Technology Data Exchange (ETDEWEB)
Kumar, N; Prakash, O [Delhi Univ. (India). Dept. of Physics and Astrophysics
1976-07-01
Shell model calculations using bare and renormalized matrix elements of the Yale potential are reported for the normal-parity states of A = 6-9 nuclei. Renormalization of the two-body matrix elements using second-order perturbation theory is not found to improve the agreements with the experimental data. Inclusion of the energy shifts of ground state rotational bands in /sup 8/Be and /sup 9/Be are, however, found to improve the agreements with the excitation energies of nuclear levels. The need for carrying out more calculations of these nuclei with realistic forces is pointed out.
SU(3) techniques for angular momentum projected matrix elements in multi-cluster problems
International Nuclear Information System (INIS)
Hecht, K.T.; Zahn, W.
1978-01-01
In the theory of integral transforms for the evaluation of the resonating group kernels needed for cluster model calculations, the evaluation of matrix elements in an angular momentum coupled basis has proved to be difficult for cluster problems involving more than two fragments. For multi-cluster wave functions SU(3) coupling and recoupling techniques can furnish a tool for the practical evaluation matrix elements in an angular momentum coupled basis if the several relative motion harmonic oscillator functions in Bargmann space have simple SU(3) coupling properties. The method is illustrated by a three-cluster problem, such as 12 C = α + α + α, involving three 1 S clusters. 2 references
Protasevich, Alexander E.; Nikitin, Andrei V.
2018-01-01
In this work, we propose an algorithm for calculating the matrix elements of the kinetic energy operator for tetrahedral molecules. This algorithm uses the dependent six-angle coordinates (6A) and takes into account the full symmetry of molecules. Unlike A.V. Nikitin, M. Rey, and Vl. G. Tyuterev who operate with the kinetic energy operator only in Radau orthogonal coordinates, we consider a general case. The matrix elements are shown to be a sum of products of one-dimensional integrals.
Role of shell structure in the 2νββ nuclear matrix elements
International Nuclear Information System (INIS)
Nakada, H.
1998-01-01
Significance of the nuclear shell structure in the ββ nuclear matrix elements is pointed out. The 2νββ processes are mainly mediated by the low-lying 1 + states. The shell structure also gives rise to concentration or fragmentation of the 2νββ components over intermediate states, depending on nuclide. These roles of the shell structure are numerically confirmed by realistic shell model calculations. Some shell structure effects are suggested for 0νββ matrix elements; dominance of low-lying intermediate states and nucleus-dependence of their spin-parities. (orig.)
LIBS detection of heavy metal elements in liquid solutions by using wood pellet as sample matrix
International Nuclear Information System (INIS)
Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong
2013-01-01
Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid sample. A new approach was presented to improve the detection limit and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions, respectively. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to obtained LOD of 0.07 ppm for Cr element in solutions. (author)
LIBS Detection of Heavy Metal Elements in Liquid Solutions by Using Wood Pellet as Sample Matrix
International Nuclear Information System (INIS)
Wen Guanhong; Sun Duixiong; Su Maogen; Dong Chenzhong
2014-01-01
Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of heavy metals in liquid samples. A new approach was presented to lower the limit of detection (LOD) and minimize the sample matrix effects, in which dried wood pellets absorbed the given amounts of Cr standard solutions and then were baked because they have stronger and rapid absorption properties for liquid samples as well as simple elemental compositions. In this work, we have taken a typical heavy metal Cr element as an example, and investigated the spectral feasibility of Cr solutions and dried wood pellets before and after absorbing Cr solutions at the same experimental conditions. The results were demonstrated to successfully produce a superior analytical response for heavy metal elements by using wood pellet as sample matrix according to the obtained LOD of 0.07 ppm for Cr element in solutions
Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.
2013-04-01
Single particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been estimated using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulphate and potassium were compared with concurrent measurements from an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal/optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and ten discrete mixing states for carbonaceous particles were identified and quantified. Potassium content was used to identify particles associated with biomass combustion. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorization, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulphate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA/EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidized OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the heterogeneity of primary and
Directory of Open Access Journals (Sweden)
R. M. Healy
2013-09-01
Full Text Available Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC, organic aerosol (OA, ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a thermal–optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC. ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78, and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the
Healy, R. M.; Sciare, J.; Poulain, L.; Crippa, M.; Wiedensohler, A.; Prévôt, A. S. H.; Baltensperger, U.; Sarda-Estève, R.; McGuire, M. L.; Jeong, C.-H.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Evans, G. J.; Wenger, J. C.
2013-09-01
Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS) as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC), organic aerosol (OA), ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), a thermal-optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC). ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67-0.78), and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA) detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA) is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA) was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA) was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the temporal
Evolution of single-particle structure of silicon isotopes
Bespalova, O. V.; Fedorov, N. A.; Klimochkina, A. A.; Markova, M. L.; Spasskaya, T. I.; Tretyakova, T. Yu.
2018-01-01
New data on proton and neutron single-particle energies E_{nlj} of Si isotopes with neutron number N from 12 to 28 as well as occupation probabilities N_{nlj} of single-particle states of stable isotopes 28, 30Si near the Fermi energy were obtained by the joint evaluation of the stripping and pick-up reaction data and excited state decay schemes of neighboring nuclei. The evaluated data indicate the following features of single-particle structure evolution: persistence of Z = 14 subshell closure with N increase, the new magicity of the number N = 16, and the conservation of the magic properties of the number N = 20 in Si isotopic chain. The features were described by the dispersive optical model. The calculation also predicts the weakening of N = 28 shell closure and demonstrates evolution of a bubble-like structure of the proton density distributions in neutron-rich Si isotopes.
Evolution of single-particle structure of silicon isotopes
Energy Technology Data Exchange (ETDEWEB)
Bespalova, O.V.; Klimochkina, A.A.; Spasskaya, T.I.; Tretyakova, T.Yu. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Fedorov, N.A.; Markova, M.L. [Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation)
2018-01-15
New data on proton and neutron single-particle energies E{sub nlj} of Si isotopes with neutron number N from 12 to 28 as well as occupation probabilities N{sub nlj} of single-particle states of stable isotopes {sup 28,30}Si near the Fermi energy were obtained by the joint evaluation of the stripping and pick-up reaction data and excited state decay schemes of neighboring nuclei. The evaluated data indicate the following features of single-particle structure evolution: persistence of Z = 14 subshell closure with N increase, the new magicity of the number N = 16, and the conservation of the magic properties of the number N = 20 in Si isotopic chain. The features were described by the dispersive optical model. The calculation also predicts the weakening of N = 28 shell closure and demonstrates evolution of a bubble-like structure of the proton density distributions in neutron-rich Si isotopes. (orig.)
Single-particle states vs. collective modes: friends or enemies ?
Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.
2018-05-01
The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The collective mode arises as the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger spacings between relevant single particle states. Thus, the single-particle state and the collective mode are "enemies" against each other. However, the nuclear forces are rich enough so as to enhance relevant collective mode by reducing the resistance power by changing single-particle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, the quantum self-organization occurs: single-particle energies can be self-organized by (i) two quantum liquids, e.g., protons and neutrons, (ii) monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger.
Single-particle potential from resummed ladder diagrams
International Nuclear Information System (INIS)
Kaiser, N.
2013-01-01
A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by calculating the complex single-particle potential U(p, k f ) + i W(p, k f ) p > k f . The on-shell single-particle potential is constructed by means of a complex-valued in-medium loop that includes corrections from a test particle of momentum vector p added to the filled Fermi sea. The single-particle potential U(k f , k f ) at the Fermi surface as obtained from the resummation of the combined particle and hole ladder diagrams is shown to satisfy the Hugenholtz-Van-Hove theorem. The perturbative contributions at various orders a n in the scattering length are deduced and checked against the known analytical results at order a 1 and a 2 . The limit a → ∞ is studied as a special case and a strong momentum dependence of the real (and imaginary) single-particle potential is found. This feature indicates an instability against a phase transition to a state with an empty shell inside the Fermi sphere such that the density gets reduced by about 5%. The imaginary single-particle potential vanishes linearly at the Fermi surface. For comparison, the same analysis is performed for the resummed particle-particle ladder diagrams alone. In this truncation an instability for hole excitations near the Fermi surface is found at strong coupling. For the set of particle-hole ring diagrams the single-particle potential is calculated as well. Furthermore, the resummation of in-medium ladder diagrams to all orders is studied for a two-dimensional Fermi gas with a short-range two-body contact interaction. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Lee, Young-Woo; Yeo, Seunghwan; Cho, Moon Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-05-15
The fuel elements for the HTGRs (i.e., spherical fuel element in pebble-bed type core design and fuel compact in prismatic core design) consists of coated fuel particles dispersed and bonded in a closely packed array within a carbonaceous matrix. This matrix is generally made by mixing fully graphitized natural and needle- or pitchcoke originated powders admixed with a binder material (pitch or phenolic resin), The resulting resinated graphite powder mixture, when compacted, may influence a number of material properties as well as its behavior under neutron irradiation during reactor operation. In the fabrication routes of these two different fuel element forms, different consolidation methods are employed; a quasi-isostatic pressing method is generally adopted to make pebbles while fuel compacts are fabricated by uni-axial pressing mode. The result showed that the hardness values obtained from the two directions showed an anisotropic behavior: The values obtained from the perpendicular section showed much higher micro hardness (176.6±10.5MPa in average) than from the parallel section ((125.6±MPa in average). This anisotropic behavior was concluded to be related to the microstructure of the matrix graphite. This may imply that the uni-axial pressing method to make compacts influence the microstructure of the matrix and hence the material properties of the matrix graphite.
Bessel equation as an operator identity's matrix element in quantum mechanics
International Nuclear Information System (INIS)
Fan Hongyi; Li Chao
2004-01-01
We study the well-known Bessel equation itself in the framework of quantum mechanics. We show that the Bessel equation is a spontaneous result of an operator identity's matrix element in some definite entangled state representations, which is a fresh look. Application of this operator formalism in the Hankel transform of Laplace equation is presented
Two-loop massive operator matrix elements for polarized and unpolarized deep-inelastic scattering
Energy Technology Data Exchange (ETDEWEB)
Bierenbaum, I.; Bluemlein, J.; Klein, S.
2007-06-15
The O({alpha}{sup 2}{sub s}) massive operator matrix elements for unpolarized and polarized heavy flavor production at asymptotic values Q{sup 2} >> m{sup 2} are calculated in Mellin space without applying the integration-by-parts method. (orig.)
Analytical matrix elements of semifinite 2D two centre nuclear potential
International Nuclear Information System (INIS)
Niculescu, V. L. R.; Catana, S.; Catana, D.; Babin, V.
1998-01-01
In the present work we introduce a new 2D potential which is a symmetric double-well in one variable and with one centre in the other. The factorable potential matrix elements are expressed by analytical formulas. This implies a shorter computational time. (author)
Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge
Brown, B A; Horoi, M
2015-01-01
The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...
Effects of quenching and partial quenching on QCD penguin matrix elements
Golterman, Maarten; Pallante, Elisabetta
2002-01-01
We point out that chiral transformation properties of penguin operators change in the transition from unquenched to (partially) quenched QCD. The way in which this affects the lattice determination of weak matrix elements can be understood in the framework of (partially) quenched chiral perturbation
Analytical Expressions of Matrix Elements of Physical Quantities for Dirac Oscillator
Institute of Scientific and Technical Information of China (English)
LI Ning; JU Guo-Xing; REN Zhong-Zhou
2004-01-01
The analytical expressions of the matrix elements for physical quantities are obtained for the Dirac oscillator in two and three spatial dimensions. Their behaviour for the case of operator's square is discussed in details. The twodimensional Dirac oscillator has similar behavior to that for three-dimensional one.
Rigorous constraints on the matrix elements of the energy–momentum tensor
Directory of Open Access Journals (Sweden)
Peter Lowdon
2017-11-01
Full Text Available The structure of the matrix elements of the energy–momentum tensor play an important role in determining the properties of the form factors A(q2, B(q2 and C(q2 which appear in the Lorentz covariant decomposition of the matrix elements. In this paper we apply a rigorous frame-independent distributional-matching approach to the matrix elements of the Poincaré generators in order to derive constraints on these form factors as q→0. In contrast to the literature, we explicitly demonstrate that the vanishing of the anomalous gravitomagnetic moment B(0 and the condition A(0=1 are independent of one another, and that these constraints are not related to the specific properties or conservation of the individual Poincaré generators themselves, but are in fact a consequence of the physical on-shell requirement of the states in the matrix elements and the manner in which these states transform under Poincaré transformations.
International Nuclear Information System (INIS)
Filippov, G.F.; Lopez Trujillo, A.; Rybkin, I.Yu.
1993-01-01
The matrix elements of the potential energy operator (which includes central, spin-orbit and tensor components) are calculated between the generating invariants of the cluster basis describing α + d and t+h configurations of the six-nucleon system. (author). 12 refs
Matching of singly- and doubly-unresolved limits of tree-level QCD squared matrix elements
Energy Technology Data Exchange (ETDEWEB)
Somogyi, Gabor [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, PO Box 51 (Hungary); Trocsanyi, Zoltan [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, PO Box 51 (Hungary); Duca, Vittorio Del [Istituto Nazionale di Fisica Nucleare, Sez. di Torino, via P. Giuria, 1 - 10125 Torino (Italy)
2005-06-01
We describe how to disentangle the singly- and doubly-unresolved (soft and/or collinear) limits of tree-level QCD squared matrix elements. Using the factorization formulae presented in this paper, we outline a viable general subtraction scheme for computing next-to-next-to-leading order corrections for electron-positron annihilation into jets.
Solution of the inverse scattering problem at fixed energy with non-physical S matrix elements
International Nuclear Information System (INIS)
Eberspaecher, M.; Amos, K.; Apagyi, B.
1999-12-01
The quantum mechanical inverse elastic scattering problem is solved with the modified Newton-Sabatier method. A set of S matrix elements calculated from a realistic analytic optical model potential serves as input data. It is demonstrated that the quality of the inversion potential can be improved by including non-physical S matrix elements to half, quarter and eighth valued partial waves if the original set does not contain enough information to determine the interaction potential. We demonstrate that results can be very sensitive to the choice of those non-physical S matrix values both with the analytic potential model and in a real application in which the experimental cross section for the symmetrical scattering system of 12 C+ 12 C at E=7.998 MeV is analyzed
International Nuclear Information System (INIS)
Tyas-Djuhariningrum
2004-01-01
The gold sample analysis can be deviated more than >10% to those thrue value caused by the matrix element. So that the matrix element character need to be study in order to reduce the deviation. In rock samples, the matrix elements can cause self quenching, self absorption and ionization process, so there is a result analysis error. In the rock geochemical process, the elements of the same group at the periodic system have the tendency to be together because of their same characteristic. In absorption Atomic Spectroscopy analysis, the elements associate can absorb primer energy with similar wave length so that it can cause deviation in the result interpretation. The aim of study is to predict matrix element influences from rock sample with application standard method for reducing deviation. In quantitative way, assessment of primer light intensity that will be absorbed is proportional to the concentration atom in the sample that relationship between photon intensity with concentration in part per million is linier (ppm). These methods for eliminating matrix elements influence consist of three methods : external standard method, internal standard method, and addition standard method. External standard method for all matrix element, internal standard method for elimination matrix element that have similar characteristics, addition standard methods for elimination matrix elements in Au, Pt samples. The third of standard posess here accuracy are about 95-97%. (author)
Modelling of polypropylene fibre-matrix composites using finite element analysis
Directory of Open Access Journals (Sweden)
2009-01-01
Full Text Available Polypropylene (PP fibre-matrix composites previously prepared and studied experimentally were modelled using finite element analysis (FEA in this work. FEA confirmed that fibre content and composition controlled stress distribution in all-PP composites. The stress concentration at the fibre-matrix interface became greater with less fibre content. Variations in fibre composition were more significant in higher stress regions of the composites. When fibre modulus increased, the stress concentration at the fibres decreased and the shear stress at the fibre-matrix interface became more intense. The ratio between matrix modulus and fibre modulus was important, as was the interfacial stress in reducing premature interfacial failure and increasing mechanical properties. The model demonstrated that with low fibre concentration, there were insufficient fibres to distribute the applied stress. Under these conditions the matrix yielded when the applied stress reached the matrix yield stress, resulting in increased fibre axial stress. When the fibre content was high, there was matrix depletion and stress transfer was inefficient. The predictions of the FEA model were consistent with experimental and published data.
International Nuclear Information System (INIS)
Ishikawa, H.; Nakano, S.; Yuuki, R.; Chung, N.Y.
1991-01-01
In the virtual crack extension method, the stress intensity factor, K, is obtained from the converged value of the energy release rate by the difference of the finite element stiffness matrix when some crack extension are taken. Instead of the numerical difference of the finite element stiffness, a new method to use a direct dirivative of the finite element stiffness matrix with respect to crack length is proposed. By the present method, the results of some example problems, such as uniform tension problems of a square plate with a center crack and a rectangular plate with an internal slant crack, are obtained with high accuracy and good efficiency. Comparing with analytical results, the present values of the stress intensity factors of the problems are obtained with the error that is less than 0.6%. This shows the numerical assurance of the usefulness of the present method. A personal computer program for the analysis is developed
Influence of Torrefaction on Single Particle Combustion of Wood
DEFF Research Database (Denmark)
Lu, Zhimin; Jian, Jie; Jensen, Peter Arendt
2016-01-01
This study focuses on the influence of torrefaction on the char reactivity, char yield, and combustion time of 3-5 mm spherical wood particles in a single particle combustion reactor (SPC) operating at a nominal temperature of 1231 °C. The devolatilization times were reduced and the char burnout...
Single-particle spectral density of the Hubbard model
Mehlig, B.; Eskes, H.; Hayn, R.; Meinders, M.B.J.
1995-01-01
We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,
SINGLE-PARTICLE SPECTRAL DENSITY OF THE HUBBARD-MODEL
MEHLIG, B; ESKES, H; HAYN, R; MEINDERS, MBJ
1995-01-01
We calculate the single-particle spectral function for the Hubbard model within the framework of a projection technique equivalent to the two-pole approximation. We show that the two-pole approximation can be well understood as an average characterization of the upper and the lower Hubbard bands,
Tomograms and the quest for single particle nonlocality
International Nuclear Information System (INIS)
Anisimov, M A; Caponigro, M; Mancini, S; Man'ko, V I
2007-01-01
By using a tomographic approach to quantum states, we rise the problem of nonlocality within a single particle (single degree of freedom). We propose a possible way to look for such effects on a qubit. Although a conclusive answer is far from being reached, we provide some reflections on the foundational ground
Single-particle behaviour in circulating fluidized beds
DEFF Research Database (Denmark)
Erik Weinell, Claus; Dam-Johansen, Kim; Johnsson, Jan Erik
1997-01-01
This paper describes an experimental investigation of single-particle behaviour in a cold pilot-scale model of a circulating fluidized bed combustor (CFBC). In the system, sand is recirculated by means of air. Pressure measurements along the riser are used to determine the suspension density...
Statistical Methods for Single-Particle Electron Cryomicroscopy
DEFF Research Database (Denmark)
Jensen, Katrine Hommelhoff
Electron cryomicroscopy (cryo-EM) is a form of transmission electron microscopy, aimed at reconstructing the 3D structure of a macromolecular complex from a large set of 2D projection images, as they exhibit a very low signal-to-noise ratio (SNR). In the single-particle reconstruction (SPR) probl...
Decay properties of high-lying single-particles modes
Beaumel, D; Fortier, S; Gales, S; Guillot, J; LangevinJoliot, H; Laurent, H; Maison, JM; Vernotte, J; Bordewijck, J; Brandenburg, S; Krasznahorkay, A; Crawley, GM; Massolo, CP; Renteria, M; Khendriche, A
1996-01-01
The neutron decay of high-lying single-particle states in Ni-64, Zr-90, Sn-120 and (208)pb excited by means of the (alpha,He-3) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular
Single particle behaviour in circulating fluidized bed combustors
DEFF Research Database (Denmark)
Erik Weinell, Claus
1994-01-01
An investigation of single particle behaviour in a circulating fluidized bed combustor is described, relating to sulphur capture reactions by limestone under alternate oxidizing and reducing conditions present in a circulating fluidized bed combustor, and to the devolatilization and burn out...
Ergodicity of a single particle confined in a nanopore
DEFF Research Database (Denmark)
Bernardi, S.; Hansen, Jesper Schmidt; Frascolli, F.
2012-01-01
-ergodic component of the phase space for energy levels typical of experiments, is surprisingly small, i.e. we conclude that the ergodic hypothesis is a reasonable approximation even for a single particle trapped in a nanopore. Due to the numerical scope of this work, our focus will be the onset of ergodic behavior...
Single-particle properties from Kohn-Sham Green's functions
International Nuclear Information System (INIS)
Bhattacharyya, Anirban; Furnstahl, R.J.
2005-01-01
An effective action approach to Kohn-Sham density functional theory is used to illustrate how the exact Green's function can be calculated in terms of the Kohn-Sham Green's function. An example based on Skyrme energy functionals shows that single-particle Kohn-Sham spectra can be improved by adding sources used to construct the energy functional
Wu, Ning
2018-01-01
For the one-dimensional spin-1/2 XX model with either periodic or open boundary conditions, it is shown by using a fermionic approach that the matrix element of the spin operator Sj- (Sj-Sj'+ ) between two eigenstates with numbers of excitations n and n +1 (n and n ) can be expressed as the determinant of an appropriate (n +1 )×(n +1 ) matrix whose entries involve the coefficients of the canonical transformations diagonalizing the model. In the special case of a homogeneous periodic XX chain, the matrix element of Sj- reduces to a variant of the Cauchy determinant that can be evaluated analytically to yield a factorized expression. The obtained compact representations of these matrix elements are then applied to two physical scenarios: (i) Nonlinear optical response of molecular aggregates, for which the determinant representation of the transition dipole matrix elements between eigenstates provides a convenient way to calculate the third-order nonlinear responses for aggregates from small to large sizes compared with the optical wavelength; and (ii) real-time dynamics of an interacting Dicke model consisting of a single bosonic mode coupled to a one-dimensional XX spin bath. In this setup, full quantum calculation up to N ≤16 spins for vanishing intrabath coupling shows that the decay of the reduced bosonic occupation number approaches a finite plateau value (in the long-time limit) that depends on the ratio between the number of excitations and the total number of spins. Our results can find useful applications in various "system-bath" systems, with the system part inhomogeneously coupled to an interacting XX chain.
Heymann, D.; Lakatos, S.; Walton, J. R.
1973-01-01
Review of the results of inert gas measurements performed on six grain-size fractions and two single particles from four samples of Luna 20 material. Presented and discussed data include the inert gas contents, element and isotope systematics, radiation ages, and Ar-36/Ar-40 systematics.
Energy Technology Data Exchange (ETDEWEB)
Pietralla, N., E-mail: pietralla@ikp.tu-darmstadt.d [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Li, T.C. [Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Fritzsche, M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ahmed, M.W. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Ahn, T.; Costin, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Enders, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Li, J. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Mueller, S.; Neumann-Cosel, P. von [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Pinayev, I.V. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Ponomarev, V.Yu.; Savran, D. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Tonchev, A.P.; Tornow, W.; Weller, H.R. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Werner, V. [A.W. Wright Nuclear Structure Laboratory (WNSL), Yale University, New Haven, CT (United States); Wu, Y.K. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany)
2009-10-26
The Pb(gamma{sup -}>,gamma{sup '}) photon scattering reaction has been studied with the nearly monochromatic, linearly polarized photon beams at the High Intensity gamma-ray Source (HIgammaS) at the DFELL. Azimuthal scattering intensity asymmetries measured with respect to the polarization plane of the beam have been used for the first time to assign both the spin and parity quantum numbers of dipole excited states of {sup 206,207,208}Pb at excitation energies in the vicinity of 5.5 MeV. Evidence for dominant particle-core coupling is deduced from these results along with information on excitation energies and electromagnetic transition matrix elements. Implications of the existence of weakly coupled states built on highly excited core states in competition with 1homega single particle (hole) excitations at comparable energies are discussed.
Neutron densities and the single particle structure of several even-even nuclei from 40Ca to 208Pb
International Nuclear Information System (INIS)
Ray, L.; Hodgson, P.E.
1979-01-01
Previously developed techniques which sum the squares of proton single particle wave functions to obtain nuclear charge densities are applied to the study of neutron distributions in /sup 40,48/Ca, /sup 58,64/Ni, /sup 116,124/Sn, and 208 Pb by comparing to those neutron densities deduced from 800 MeV proton elastic scattering data. The proton and neutron single particle wave functions are derived from a one-body, nonlocal Woods-Saxon binding potential whose parameters are adjusted to give the experimental single particle energies. Empirical spectroscopic factors determine the appropriate occupation probabilities for the single particle levels near the Fermi surface. Proper attention is given to nonorthogonality problems and to the removal of the spurious center-of-mass motion. These semiphenomenological neutron densities are compared to the predictions of the density matrix expansion variant of Hartree-Fock theory and to densities which are empirically deduced from recent 800 MeV polarized proton elastic scattering data. These ''experimental'' neutron distributions are obtained from approximate second order Kerman, McManus, and Thaler optical potential analyses using essentially ''model independent'' neutron densities. Qualitatively good agreement is obtained between the semiphenomenological neutron densities computed here, the density matrix expansion predictions, and the empirical results
Bubin, Sergiy; Adamowicz, Ludwik
2006-06-14
In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programmed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.
Bubin, Sergiy; Adamowicz, Ludwik
2006-06-01
In this work we present analytical expressions for Hamiltonian matrix elements with spherically symmetric, explicitly correlated Gaussian basis functions with complex exponential parameters for an arbitrary number of particles. The expressions are derived using the formalism of matrix differential calculus. In addition, we present expressions for the energy gradient that includes derivatives of the Hamiltonian integrals with respect to the exponential parameters. The gradient is used in the variational optimization of the parameters. All the expressions are presented in the matrix form suitable for both numerical implementation and theoretical analysis. The energy and gradient formulas have been programed and used to calculate ground and excited states of the He atom using an approach that does not involve the Born-Oppenheimer approximation.
DEFF Research Database (Denmark)
Frederiksson, Per; Gudmundson, Peter; Mikkelsen, Lars Pilgaard
2009-01-01
A framework of finite element equations for strain gradient plasticity is presented. The theoretical framework requires plastic strain degrees of freedom in addition to displacements and a plane strain version is implemented into a commercial finite element code. A couple of different elements...... of quadrilateral type are examined and a few numerical issues are addressed related to these elements as well as to strain gradient plasticity theories in general. Numerical results are presented for an idealized cell model of a metal matrix composite under shear loading. It is shown that strengthening due...... to fiber size is captured but strengthening due to fiber shape is not. A few modelling aspects of this problem are discussed as well. An analytic solution is also presented which illustrates similarities to other theories....
Correlated random-phase approximation from densities and in-medium matrix elements
Energy Technology Data Exchange (ETDEWEB)
Trippel, Richard; Roth, Robert [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)
2016-07-01
The random-phase approximation (RPA) as well as the second RPA (SRPA) are established tools for the study of collective excitations in nuclei. Addressing the well known lack of correlations, we derived a universal framework for a fully correlated RPA based on the use of one- and two-body densities. We apply densities from coupled cluster theory and investigate the impact of correlations. As an alternative approach to correlations we use matrix elements transformed via in-medium similarity renormalization group (IM-SRG) in combination with RPA and SRPA. We find that within SRPA the use of IM-SRG matrix elements leads to the disappearance of instabilities of low-lying states. For the calculations we use normal-ordered two- plus three-body interactions derived from chiral effective field theory. We apply different Hamiltonians to a number of doubly-magic nuclei and calculate electric transition strengths.
Two-loop operator matrix elements for massive fermionic local twist-2 operators in QED
International Nuclear Information System (INIS)
Bluemlein, J.; Freitas, A. de; Universidad Simon Bolivar, Caracas; Neerven, W.L. van
2011-11-01
We describe the calculation of the two--loop massive operator matrix elements with massive external fermions in QED. We investigate the factorization of the O(α 2 ) initial state corrections to e + e - annihilation into a virtual boson for large cms energies s >>m 2 e into massive operator matrix elements and the massless Wilson coefficients of the Drell-Yan process adapting the color coefficients to the case of QED, as proposed by F. A. Berends et. al. (Nucl. Phys. B 297 (1988)429). Our calculations show explicitly that the representation proposed there works at one-loop order and up to terms linear in ln (s/m 2 e ) at two-loop order. However, the two-loop constant part contains a few structural terms, which have not been obtained in previous direct calculations. (orig.)
Short-distance matrix elements for $D$-meson mixing for 2+1 lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Chang, Chia Cheng [Univ. of Illinois, Champaign, IL (United States)
2015-01-01
We study the short-distance hadronic matrix elements for D-meson mixing with partially quenched N_{f} = 2+1 lattice QCD. We use a large set of the MIMD Lattice Computation Collaboration's gauge configurations with a^{2} tadpole-improved staggered sea quarks and tadpole-improved Lüscher-Weisz gluons. We use the a^{2} tadpole-improved action for valence light quarks and the Sheikoleslami-Wohlert action with the Fermilab interpretation for the valence charm quark. Our calculation covers the complete set of five operators needed to constrain new physics models for D-meson mixing. We match our matrix elements to the MS-NDR scheme evaluated at 3 GeV. We report values for the Beneke-Buchalla-Greub-Lenz-Nierste choice of evanescent operators.
Kinetic-energy matrix elements for atomic Hylleraas-CI wave functions
Energy Technology Data Exchange (ETDEWEB)
Harris, Frank E., E-mail: harris@qtp.ufl.edu [Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA and Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, Florida 32611 (United States)
2016-05-28
Hylleraas-CI is a superposition-of-configurations method in which each configuration is constructed from a Slater-type orbital (STO) product to which is appended (linearly) at most one interelectron distance r{sub ij}. Computations of the kinetic energy for atoms by this method have been difficult due to the lack of formulas expressing these matrix elements for general angular momentum in terms of overlap and potential-energy integrals. It is shown here that a strategic application of angular-momentum theory, including the use of vector spherical harmonics, enables the reduction of all atomic kinetic-energy integrals to overlap and potential-energy matrix elements. The new formulas are validated by showing that they yield correct results for a large number of integrals published by other investigators.
Lattice calculation of hadronic weak matrix elements: the ΔI = 1/2 rule
International Nuclear Information System (INIS)
Bernard, C.
1984-01-01
A lattice Monte Carlo technique for calculating the matrix elements of weak operators is described. Emphasis is placed on the ΔI = 1/2 rule, which is such a large effect that the significant errors associated with current lattice methods (statistics, finite size, finite lattice spacing, extrapolations in quark mass, etc.) should not disguise the important qualitative features. A detailed exposition of the analytic bases for the calculation is given, and an attempt is made to avoid the questionable phenomenological assumptions (such as some of those inherent in the Penguin approach) which were necessary when matrix elements could not be calculated. The current state of the calculation-in-progress is described. This work is being done in collaboration with A. Soni, T. Draper, G. Hockney, and M. Rushton
Current matrix element in HAL QCD's wavefunction-equivalent potential method
Watanabe, Kai; Ishii, Noriyoshi
2018-04-01
We give a formula to calculate a matrix element of a conserved current in the effective quantum mechanics defined by the wavefunction-equivalent potentials proposed by the HAL QCD collaboration. As a first step, a non-relativistic field theory with two-channel coupling is considered as the original theory, with which a wavefunction-equivalent HAL QCD potential is obtained in a closed analytic form. The external field method is used to derive the formula by demanding that the result should agree with the original theory. With this formula, the matrix element is obtained by sandwiching the effective current operator between the left and right eigenfunctions of the effective Hamiltonian associated with the HAL QCD potential. In addition to the naive one-body current, the effective current operator contains an additional two-body term emerging from the degrees of freedom which has been integrated out.
On the estimation of matrix elements for optical transitions in semiconductors
International Nuclear Information System (INIS)
Hassan, A.R.
1992-09-01
A semi-empirical method is used to calculate the numerical values of the interband momentum matrix elements of the allowed optical transitions in semiconductors. This method is based on the evaluation of the ratio of the two-photon and one-photon absorption coefficients and the compare the result with the corresponding experimental values in a number of semiconductors both for direct and indirect transition processes. The numerical values of the momentum matrix elements are compared with the convenient theoretical calculations available. The result is found to agree fairly well with the corresponding values computed using the k-vector · p-vector perturbation theory. (author). 19 refs, 2 figs, 2 tabs
Study of the Matrix Effect on the Plasma Characterization of Heavy Elements in Soil Sediments
Directory of Open Access Journals (Sweden)
Tawfik W.
2007-01-01
Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to perform a study of the matrix effect on the plasma characterization of soil sediment targets. The plasma is generated by focusing a pulsed Nd: YAG laser on the target in air at atmospheric pressure. The plasma emission spectrum was detected using a portable Echelle spectrometer (Mechelle 7500 — Multichannel Instruments, Stockholm, Sweden with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, and electron temperature. Four heavy elements V, Pb, Mn and Co were determined in the obtained spectra. The LTE and optically thin plasma conditions were verified for the produced plasma. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of the spectral lines of the heavy elements in the soil sediments. The electron temperature does not change with concentration. For environmental applications, the obtained results showed the capability of the proposed LIBS setup with the portable Mechelle 7500 spectrometer to be applied in-situ for real-time measurements of the variation of the matrix elemental composition of soil sediments by following up only a single element as a marker for the composition of the soil sediment without need of analysis of the other elements.
Reactor calculation in coarse mesh by finite element method applied to matrix response method
International Nuclear Information System (INIS)
Nakata, H.
1982-01-01
The finite element method is applied to the solution of the modified formulation of the matrix-response method aiming to do reactor calculations in coarse mesh. Good results are obtained with a short running time. The method is applicable to problems where the heterogeneity is predominant and to problems of evolution in coarse meshes where the burnup is variable in one same coarse mesh, making the cross section vary spatially with the evolution. (E.G.) [pt
Heavy flavor operator matrix elements at O({alpha}{sub s}{sup 3})
Energy Technology Data Exchange (ETDEWEB)
Bierenbaum, Isabella; Buemlein, Johannes; Klein, Sebastian
2008-12-15
The heavy quark effects in deep.inelastic scattering in the asymptotic regime Q{sup 2}>>m{sup 2} can be described by heavy flavor operator matrix elements. Complete analytic expressions for these objects are currently known to NLO. We present first results for fixed moments at NNLO. This involves a recalculation of fixed moments of the corresponding NNLO anomalous dimensions, which we thereby confirm. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J.; Hasselhuhn, A.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); IHES, Bures-sur-Yvette (France)
2017-05-15
Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines with two different masses. In the case of the charm and bottom quarks, the usual decoupling of one heavy mass at a time no longer holds, since the ratio of the respective masses, η=m{sup 2}{sub c}/m{sup 2}{sub b}∝1/10, is not small enough. Therefore, the usual variable flavor number scheme (VFNS) has to be generalized. The renormalization procedure in the two-mass case is different from the single mass case derived earlier (I. Bierenbaum, J: Bluemlein, S. Klein, 2009). We present the moments N=2,4 and 6 for all contributing operator matrix elements, expanding in the ratio η. We calculate the analytic results for general values of the Mellin variable N in the flavor non-singlet case, as well as for transversity and the matrix element A{sup (3)}{sub gq}. We also calculate the two-mass scalar integrals of all topologies contributing to the gluonic operator matrix element A{sub gg}. As it turns out, the expansion in η is usually inapplicable for general values of N. We therefore derive the result for general values of the mass ratio. From the single pole terms we derive, now in a two-mass calculation, the corresponding contributions to the 3-loop anomalous dimensions. We introduce a new general class of iterated integrals and study their relations and present special values. The corresponding functions are implemented in computer-algebraic form.
Three-loop contributions to the gluonic massive operator matrix elements at general values of N
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Hasselhuhn, Alexander [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Bluemlein, Johannes; Raab, Clemens [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); De Freitas, Abilio; Round, Mark; Schneider, Carsten; Wissbrock, Fabian [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Klein, Sebastian [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik E
2012-12-15
Recent results on the calculation of 3-loop massive operator matrix elements in case of one and two heavy quark masses are reported. They concern the O(n{sub f}T{sup 2}{sub F}C{sub F,A}) and O(T{sup 2}{sub F}C{sub F,A}) gluonic corrections, two-mass quarkonic moments, and ladder- and Benz-topologies. We also discuss technical aspects of the calculations.
K-M matrix elements and decays of the B meson to J/Psi
International Nuclear Information System (INIS)
Wilson, Richard
2002-01-01
This talk discusses some of the last work on B meson decays of the CLEO collaboration, which work is, in fact, improvements in precision of much earlier work of the same collaboration. New theoretical developments have enabled us to present much improved numbers on the matrix elements Vcb, and Vub. Also some recent work on the decay of B mesons to J/Psi plus other particles will be briefly presented
International Nuclear Information System (INIS)
Rajput, B.S.
1977-01-01
Using the reduced expansions of second quantized electromagnetic vector potential operator in terms of irreducible representations of Pioncare group in the interaction Hamiltonian, the exact matrix elements of interaction of electromagnetic field with a hydrogenic atom have been derived and the contributions of transitions for different combinations of angular momentum quantum numbers to the transition probabilities of various lines in Lyman-, Balmer-, and Paschen-series have been computed. (author)
Quenching of the Gamow-Teller matrix element in closed LS-shell-plus-one nuclei
International Nuclear Information System (INIS)
Towner, I.S.
1989-06-01
It is evident that nuclear Gamow-Teller matrix elements determined from β-decay and charge-exchange reactions are significantly quenched compared to simple shell-model estimates based on one-body operators and free-nucleon coupling constants. Here we discuss the theoretical origins of this quenching giving examples from light nuclei near LS-closed shells, such as 16 0 and 40 Ca. (Author) 12 refs., 2 tabs
Off-diagonal helicity density matrix elements for vector mesons produced at LEP
International Nuclear Information System (INIS)
Anselmino, M.; Bertini, M.; Quintairos, P.
1997-05-01
Final state q q-bar interactions may give origin to non zero values of the off-diagonal element ρ 1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ and D * 's. Predictions are given for ρ1,-1 of several mesons produced at large z and small PT, collinear with the parent jet; the values obtained for θ and D * are in agreement with data. (author)
Nucleon scalar matrix elements with N{sub f}=2+1+1 twisted mass fermions
Energy Technology Data Exchange (ETDEWEB)
Dinter, Simon; Drach, Vincent; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC
2011-12-15
We investigate scalar matrix elements of the nucleon using N{sub f}=2+1+1 flavors of maximally twisted mass fermions at a fixed value of the lattice spacing of a{approx}0.078 fm. We compute disconnected contributions to the relevant three-point functions using an efficient noise reduction technique. Using these methods together with an only multiplicative renormalization applicable for twisted mass fermions, allows us to obtain accurate results in the light and strange sector. (orig.)
Directory of Open Access Journals (Sweden)
J. Ablinger
2017-08-01
Full Text Available Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines with two different masses. In the case of the charm and bottom quarks, the usual decoupling of one heavy mass at a time no longer holds, since the ratio of the respective masses, η=mc2/mb2∼1/10, is not small enough. Therefore, the usual variable flavor number scheme (VFNS has to be generalized. The renormalization procedure in the two-mass case is different from the single mass case derived in [1]. We present the moments N=2,4 and 6 for all contributing operator matrix elements, expanding in the ratio η. We calculate the analytic results for general values of the Mellin variable N in the flavor non-singlet case, as well as for transversity and the matrix element Agq(3. We also calculate the two-mass scalar integrals of all topologies contributing to the gluonic operator matrix element Agg. As it turns out, the expansion in η is usually inapplicable for general values of N. We therefore derive the result for general values of the mass ratio. From the single pole terms we derive, now in a two-mass calculation, the corresponding contributions to the 3-loop anomalous dimensions. We introduce a new general class of iterated integrals and study their relations and present special values. The corresponding functions are implemented in computer-algebraic form.
Separation of soft and collinear infrared limits of QCD squared matrix elements
Nagy, Zoltan; Trócsányi, Z L; Trocsanyi, Zoltan; Somogyi, Gabor; Trocsanyi, Zoltan
2007-01-01
We present a simple way of separating the overlap between the soft and collinear factorization formulae of QCD squared matrix elements. We check its validity explicitly for single and double unresolved emissions of tree-level processes. The new method makes possible the definition of helicity-dependent subtraction terms for regularizing the real contributions in computing radiative corrections to QCD jet cross sections. This implies application of Monte Carlo helicity summation in computing higher order corrections.
Collective and single-particle states at high excitation energy
International Nuclear Information System (INIS)
Van den Berg, A.M.; Van der Molen, H.K.T.; Harakeh, M.N.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Ihara, F.; Inomata, T.
2000-01-01
Complete text of publication follows. Damping of high-lying single-particle states was investigated by the study of proton decay from high-lying states in 91 Nb, populated by the 90 Zr(α,t) reaction with E α = 180 MeV. In addition to decay to the ground state of 90 Zr, semi-direct decay was observed to the low-lying (2 + and 3 - ) phonon states, confirming the conclusion from other experiments that these phonon states play an important role in the damping process of the single-particle states. Furthermore, the population and decay of Isobaric Analogue States of 91 Zr, which are located at an excitation energy of about 10 - 12 MeV in 91 Nb, has been studied in the same reaction. (author)
Matrix elements and few-body calculations within the unitary correlation operator method
International Nuclear Information System (INIS)
Roth, R.; Hergert, H.; Papakonstantinou, P.
2005-01-01
We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges. (orig.)
Matrix elements and few-body calculations within the unitary correlation operator method
International Nuclear Information System (INIS)
Roth, R.; Hergert, H.; Papakonstantinou, P.; Neff, T.; Feldmeier, H.
2005-01-01
We employ the unitary correlation operator method (UCOM) to construct correlated, low-momentum matrix elements of realistic nucleon-nucleon interactions. The dominant short-range central and tensor correlations induced by the interaction are included explicitly by an unitary transformation. Using correlated momentum-space matrix elements of the Argonne V18 potential, we show that the unitary transformation eliminates the strong off-diagonal contributions caused by the short-range repulsion and the tensor interaction and leaves a correlated interaction dominated by low-momentum contributions. We use correlated harmonic oscillator matrix elements as input for no-core shell model calculations for few-nucleon systems. Compared to the bare interaction, the convergence properties are dramatically improved. The bulk of the binding energy can already be obtained in very small model spaces or even with a single Slater determinant. Residual long-range correlations, not treated explicitly by the unitary transformation, can easily be described in model spaces of moderate size allowing for fast convergence. By varying the range of the tensor correlator we are able to map out the Tjon line and can in turn constrain the optimal correlator ranges
International Nuclear Information System (INIS)
Elyutin, P V; Rubtsov, A N
2008-01-01
The energy evolution of a quantum chaotic system under the perturbation that harmonically depends on time is studied for the case of large perturbation, in which the rate of transition calculated from the Fermi golden rule (FGR) is about or exceeds the frequency of perturbation. For this case, the models of the Hamiltonian with random non-correlated matrix elements demonstrate that the energy evolution retains its diffusive character, but the rate of diffusion increases slower than the square of the magnitude of perturbation, thus destroying the quantum-classical correspondence for the energy diffusion and the energy absorption in the classical limit ℎ → 0. The numerical calculation carried out for a model built from the first principles (the quantum analog of the Pullen-Edmonds oscillator) demonstrates that the evolving energy distribution, apart from the diffusive component, contains a ballistic one with the energy dispersion that is proportional to the square of time. This component originates from the chains of matrix elements with correlated signs and vanishes if the signs of matrix elements are randomized. The presence of the ballistic component formally extends the applicability of the FGR to the non-perturbative domain and restores the quantum-classical correspondence
Matching NLO parton shower matrix element with exact phase space case of $W\\to l\
Nanava, G; Was, Z
2010-01-01
In practical applications PHOTOS Monte Carlo is often used for simulation of QED effects in decay of intermediate particles and resonances. Generated in such a way that samples of events cover the whole bremsstrahlung phase space. With the help of selection cuts, experimental acceptance can be then taken into account. The program is based on exact multiphoton phase space. To evaluate the program precision it is necessary to control its matrix element. Generally it is obtained using iteration of the universal multidimensional kernel. In some cases it is however obtained from the exact first order matrix element. Then, as a consequence, all terms necessary for non-leading logarithms are taken into account. In the present paper we will focus on the decays W -> l nu and gamma^* -> pi^+ pi^-. The Born level cross sections for both processes approach zero in some points of the phase space. Process dependent, compensating weight is constructed to implement exact matrix element, but it will be recommended for use onl...
A generalized Talmi-Moshinsky transformation for few-body and direct interaction matrix elements
International Nuclear Information System (INIS)
Tobocman, W.
1981-01-01
A set of basis states for use in evaluating matrix elements of few-body system operators is suggested. These basis states are products of harmonic oscillator wave functions having as arguments a set of Jacobi coordinates for the system. We show that these harmonic oscillator functions can be chosen in a manner that allows such a product to be expanded as a finite sum of the corresponding products for any other set of Jacobi coordinates. This result is a generalization of the Talmi-Moshinsky transformation for two equal-mass particles to a system of any number of particles of arbitrary masses. With the help of our method the multidimensional integral which must be performed to evaluate a few-body matrix element can be transformed into a sum of products of three dimensional integrals. The coefficients in such an expansion are generalized Talmi-Moshinsky coefficients. The method is tested by calculation of a matrix element for knockout scattering for a simple three-body-system. The results indicate that the method is a viable calculational tool. (orig.)
Spin resonance strength calculation through single particle tracking for RHIC
Energy Technology Data Exchange (ETDEWEB)
Luo, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2015-05-03
The strengths of spin resonances for the polarized-proton operation in the Relativistic Heavy Ion Collider are currently calculated with the code DEPOL, which numerically integrates through the ring based on an analytical approximate formula. In this article, we test a new way to calculate the spin resonance strengths by performing Fourier transformation to the actual transverse magnetic fields seen by a single particle traveling through the ring. Comparison of calculated spin resonance strengths is made between this method and DEPOL.
Fragmentation of single-particle states in deformed nuclei
International Nuclear Information System (INIS)
Malov, L.A.; Soloviev, V.G.
1975-01-01
Fragmentation of single-particle states on levels of deformed nuclei is studied on the example of 239 U and 169 Er nuclei in the framework of the model taking into consideration the interaction of quasiparticles with phonons. The dependence of fragmentation on the Fermi surface is considered from the viewpoint of single-particle levels. It is shown that in the distribution of single-particle strength functions a second maximum appears together with the large asymmetry maximum at high-energy excitation, and the distribution has a long ''tail''. A semimicroscopic approach is proposed for calculating the neutron strength functions. The following values of the strength functions are obtained: for sub(239)U-Ssub(0)sup(cal)=1.2x10sup(-4), Ssub(1)sup(cal)=2.7x10sub(-4) and for sub(169)Er-Ssub(0)sup(cal)=1.10sup(-4), Ssub(1)sup(cal)=1.2x10sup(-4)
Single Particle Soot Photometer intercomparison at the AIDA chamber
Directory of Open Access Journals (Sweden)
M. Laborde
2012-12-01
Full Text Available Soot particles, consisting of black carbon (BC, organic carbon (OC, inorganic salts, and trace elements, are emitted into the atmosphere during incomplete combustion. Accurate measurements of atmospheric BC are important as BC particles cause adverse health effects and impact the climate.
Unfortunately, the accurate measurement of the properties and mass concentrations of BC particles remains difficult. The Single Particle Soot Photometer (SP2 can contribute to improving this situation by measuring the mass of refractory BC in individual particles as well as its mixing state.
Here, the results of the first detailed SP2 intercomparison, involving 6 SP2s from 6 different research groups, are presented, including the most evolved data products that can presently be calculated from SP2 measurements.
It was shown that a detection efficiency of almost 100% down to 1 fg BC per particle can readily be achieved, and that this limit can be pushed down to ∼0.2 fg BC with optimal SP2 setup. Number and mass size distributions of BC cores agreed within ±5% and ±10%, respectively, in between the SP2s, with larger deviations in the range below 1 fg BC.
The accuracy of the SP2's mass concentration measurement depends on the calibration material chosen. The SP2 has previously been shown to be equally sensitive to fullerene soot and ambient BC from sources where fossil fuel was dominant and less sensitive to fullerene soot than to Aquadag. Fullerene soot was therefore chosen as the standard calibration material by the SP2 user community; however, many data sets rely solely on Aquadag calibration measurements. The difference in SP2 sensitivity was found to be almost equal (fullerene soot to Aquadag response ratio of ∼0.75 at 8.9 fg BC for all SP2s. This allows the calculation of a fullerene soot equivalent calibration curve from a measured Aquadag calibration, when no fullerene soot calibration is available. It could be
Effect of the Heat Treatment on the Graphite Matrix of Fuel Element for HTGR
International Nuclear Information System (INIS)
Lee, Chungyong; Lee, Seungjae; Suh, Jungmin; Jo, Youngho; Lee, Youngwoo; Cho, Moonsung
2013-01-01
In this paper, the cylinder-formed fuel element for the block type reactor is focused on, which consists of the large part of graphite matrix. One of the most important properties of the graphite matrix is the mechanical strength for the high reliability because the graphite matrix should be enabled to protect the TRISO particles from the irradiation environment and the impact from the outside. In this study, the three kinds of candidate graphites and Phenol as a binder were chosen and mixed with each other, formed and heated for the compressive strength test. The objective of this research is to optimize the kinds and composition of the mixed graphite and the forming process by evaluating the compressive strength before/after heat treatment (carbonization of binder). In this study, the effect of heat treatment on graphite matrix was studied in terms of the density and the compressive strength. The size (diameter and length) of pellet is increased by heat treatment. Due to additional weight reduction and swelling (length and diameter) of samples the density of graphite pellet is decreased from about 2.0 to about 1.7g/cm 3 . From the mechanical test results, the compressive strength of graphite pellets was related to the various conditions such as the contents of binder, the kinds of graphite and the heat treatment. Both the green pellet and the heat treated pellet, the compressive strength of G+S+P pellets is relatively higher than that of R+S+P pellets. To optimize fuel element matrix, the effect of Phenol and other binders, graphite composition and the heat treatment on the mechanical properties will be deeply investigated for further study
A Data Matrix Method for Improving the Quantification of Element Percentages of SEM/EDX Analysis
Lane, John
2009-01-01
A simple 2D M N matrix involving sample preparation enables the microanalyst to peer below the noise floor of element percentages reported by the SEM/EDX (scanning electron microscopy/ energy dispersive x-ray) analysis, thus yielding more meaningful data. Using the example of a 2 3 sample set, there are M = 2 concentration levels of the original mix under test: 10 percent ilmenite (90 percent silica) and 20 percent ilmenite (80 percent silica). For each of these M samples, N = 3 separate SEM/EDX samples were drawn. In this test, ilmenite is the element of interest. By plotting the linear trend of the M sample s known concentration versus the average of the N samples, a much higher resolution of elemental analysis can be performed. The resulting trend also shows how the noise is affecting the data, and at what point (of smaller concentrations) is it impractical to try to extract any further useful data.
International Nuclear Information System (INIS)
Li, Guo-Qing; Miao, Xing-Yuan; Hu, Yuan-Tai; Wang, Ji
2013-01-01
A comprehensive study on smart beams with piezoelectric elements using an impedance matrix and the inverse Laplace transform is presented. Based on the authors’ previous work, the dynamics of some elements in beam-like smart structures are represented by impedance matrix equations, including a piezoelectric stack, a piezoelectric bimorph, an elastic straight beam or a circular curved beam. A further transform is applied to the impedance matrix to obtain a set of implicit transfer function matrices. Apart from the analytical solutions to the matrices of smart beams, one computation procedure is proposed to obtained the impedance matrices and transfer function matrices using FEA. By these means the dynamic solution of the elements in the frequency domain is transformed to that in Laplacian s-domain and then inversely transformed to time domain. The connections between the elements and boundary conditions of the smart structures are investigated in detail, and one integrated system equation is finally obtained using the symbolic operation of TF matrices. A procedure is proposed for dynamic analysis and control analysis of the smart beam system using mode superposition and a numerical inverse Laplace transform. The first example is given to demonstrate building transfer function associated impedance matrices using both FEA and analytical solutions. The second example is to verify the ability of control analysis using a suspended beam with PZT patches under close-loop control. The third example is designed for dynamic analysis of beams with a piezoelectric stack and a piezoelectric bimorph under various excitations. The last example of one smart beam with a PPF controller shows the applicability to the control analysis of complex systems using the proposed method. All results show good agreement with the other results in the previous literature. The advantages of the proposed methods are also discussed at the end of this paper. (paper)
X-ray microanalysis of elements present in the matrix of cnidarian nematocysts.
Tardent, P; Zierold, K; Klug, M; Weber, J
1990-01-01
The composition and concentration of elements, in particular those of metallic cations, present in the intracapsular matrix and the wall of nematocysts of various cnidarian species have been recorded by means of X-ray microanalysis performed on 100nm thick cryosections. The predominant cation detected in the nematocyst matrix of the hydrozoan Podocoryne carnea (medusa), the scyphozoan Aurelia aurita (scyphopolyp) and the anthozoan Calliactis parasitica (tentacles and acontia) is K(+). Mg(2+) prevails in tentacular cysts of Anthopleura elegantissima, Actinia equina and Anemonia viridis, whereas, the acrorhagial cysts of A. elegantissima and A. equina contain Ca(2+) instead of Mg(2+). The acrorhagial cysts of A. viridis contain Mg(2+) like those of the tentacles. In the tentacular nematocysts of Podocoryne carnea polyps (Hydrozoa) on the other hand ambiguous element contents were found indicating that the cysts of this species has no preference for a particular cation. The high values of sulfur recorded in the matrix and particularly the wall of all the cysts are reflecting the presence of numerous protein disulfide bonds within the structural components (wall, shaft, tubule) of the nematocysts.
International Nuclear Information System (INIS)
Lee, Young-Woo; Yeo, Seunghwan; Cho, Moon Sung
2015-01-01
The carbonization is a process step where the binder that is incorporated during the matrix graphite powder preparation step is evaporated and the residue of the binder is carbonized during the heat treatment at about 1073 K. This carbonization step is followed by the final high temperature heat treatment where the carbonized compacts are heat treated at 2073-2173 K in vacuum for a relatively short time (about 2 hrs). In order to develop a fuel compact fabrication technology, and for fuel matrix graphite to meet the required material properties, it is essential to investigate the relationship among the process parameters of the matrix graphite powder preparation, the fabrication parameters of fuel element green compact and the heat treatments conditions, which has a strong influence on the further steps and the material properties of fuel element. In this work, the dimensional changes of green compacts during the carbonization and final heat treatment are evaluated when compacts have different densities from different pressing conditions and different final heat treatment temperatures are employed, keeping other process parameters constant, such as the binder content, carbonization time, temperature and atmosphere (two hours ant 1073K and N2 atmosphere). In this work, the dimensional variations of green compacts during the carbonization and final heat treatment are evaluated when compacts have different densities from different pressing conditions and different final heat treatment temperatures are employed
On the possibility to measure 0νββ-decay nuclear matrix element for 48Ca
International Nuclear Information System (INIS)
Rodin, Vadim
2011-01-01
As shown in Ref. [2], the Fermi part M F 0ν of the total 0νββ-decay nuclear matrix element M 0ν can be related to the single Fermi transition matrix element between the isobaric analog state (IAS) of the ground state of the initial nucleus and the ground state of the final nucleus. The latter matrix element could be measured in charge-exchange reactions. Here we discuss a possibility of such a measurement for 48 Ca and estimate the cross-section of the reaction 48 Ti(n,p) 48 Sc(IAS).
Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements
Energy Technology Data Exchange (ETDEWEB)
Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)
2011-12-16
A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.
Emissions from Ethanol-Gasoline Blends: A Single Particle Perspective
Directory of Open Access Journals (Sweden)
Peter H. McMurry
2011-06-01
Full Text Available Due to its agricultural origin and function as a fuel oxygenate, ethanol is being promoted as an alternative biomass-based fuel for use in spark ignition engines, with mandates for its use at state and regional levels. While it has been established that the addition of ethanol to a fuel reduces the particulate mass concentration in the exhaust, little attention has been paid to changes in the physicochemical properties of the emitted particles. In this work, a dynamometer-mounted GM Quad-4 spark ignition engine run without aftertreatment at 1,500 RPM and 100% load was used with four different fuel blends, containing 0, 20, 40 and 85 percent ethanol in gasoline. This allowed the effects of the fuel composition to be isolated from other effects. Instrumentation employed included two Aerosol Time-of-Flight Mass Spectrometers covering different size ranges for analysis of single particle composition, an Aethalometer for black carbon, a Scanning Mobility Particle Sizer for particle size distributions, a Photoelectric Aerosol Sensor for particle-bound polycyclic aromatic hydrocarbon (PAH species and gravimetric filter measurements for particulate mass concentrations. It was found that, under the conditions investigated here, additional ethanol content in the fuel changes the particle size distribution, especially in the accumulation mode, and decreases the black carbon and total particulate mass concentrations. The molecular weight distribution of the PAHs was found to decrease with added ethanol. However, PAHs produced from higher ethanol-content fuels are associated with NO2− (m/z—46 in the single-particle mass spectra, indicating the presence of nitro-PAHs. Compounds associated with the gasoline (e.g., sulfur-containing species are diminished due to dilution as ethanol is added to the fuel relative to those associated with the lubricating oil (e.g., calcium, zinc, phosphate in the single particle spectra. These changes have potential
New apparatus of single particle trap system for aerosol visualization
Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio
2014-08-01
Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.
IMPACT OF MATRIX INVERSION ON THE COMPLEXITY OF THE FINITE ELEMENT METHOD
Directory of Open Access Journals (Sweden)
M. Sybis
2016-04-01
Full Text Available Purpose. The development of a wide construction market and a desire to design innovative architectural building constructions has resulted in the need to create complex numerical models of objects having increasingly higher computational complexity. The purpose of this work is to show that choosing a proper method for solving the set of equations can improve the calculation time (reduce the complexity by a few levels of magnitude. Methodology. The article presents an analysis of the impact of matrix inversion algorithm on the deflection calculation in the beam, using the finite element method (FEM. Based on the literature analysis, common methods of calculating set of equations were determined. From the found solutions the Gaussian elimination, LU and Cholesky decomposition methods have been implemented to determine the effect of the matrix inversion algorithm used for solving the equations set on the number of computational operations performed. In addition, each of the implemented method has been further optimized thereby reducing the number of necessary arithmetic operations. Findings. These optimizations have been performed on the use of certain properties of the matrix, such as symmetry or significant number of zero elements in the matrix. The results of the analysis are presented for the division of the beam to 5, 50, 100 and 200 nodes, for which the deflection has been calculated. Originality. The main achievement of this work is that it shows the impact of the used methodology on the complexity of solving the problem (or equivalently, time needed to obtain results. Practical value. The difference between the best (the less complex and the worst (the most complex is in the row of few orders of magnitude. This result shows that choosing wrong methodology may enlarge time needed to perform calculation significantly.
To the evaluation of single-particle strengths of states
International Nuclear Information System (INIS)
Ochirbat, G.
1976-01-01
Method of Green's function has been applied to calculating the distribution of single-particle states over actual nuclear levels. Chain of equations for these functions has been obtained in a model of interacting phonons and quasiparticles. It has been noticed that cutting the chain of equations by means of neglecting the higher order Green function corresponds to neglecting the higher order components of the wave function in variational methods. The one- and two-phonon approximations are discussed and the convenience of the Green function method for this case is demonstrated
Single-particle and collective excitations in Ni-63
Albers, M.; Zhu, S.; Janssens, R. V. F.; Gellanki, Jnaneswari; Ragnarsson, Ingemar; Alcorta, M.; Baugher, T.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Deacon, A. N.; Gade, A.; DiGiovine, B.; Hoffman, C. R.
2013-01-01
A study of excited states in Ni-63 up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg-26(Ca-48,2 alpha 3n gamma)Ni-63 reaction at beam energies between 275 and 320 MeV. Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith quantifying the deformation at high spin. The results have been compared with shell-model and cranked Nilsson-...
Single particle tracking and single molecule energy transfer
Bräuchle, Christoph; Michaelis, Jens
2009-01-01
Closing a gap in the literature, this handbook gathers all the information on single particle tracking and single molecule energy transfer. It covers all aspects of this hot and modern topic, from detecting virus entry to membrane diffusion, and from protein folding using spFRET to coupled dye systems, as well recent achievements in the field. Throughout, the first-class editors and top international authors present content of the highest quality, making this a must-have for physical chemists, spectroscopists, molecular physicists and biochemists.
Decay properties of high-lying single-particles modes
Beaumel, D.; Fortier, S.; Galès, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J. M.; Vernotte, J.; Bordewijck, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G. M.; Massolo, C. P.; Renteria, M.; Khendriche, A.
1996-02-01
The neutron decay of high-lying single-particle states in 64Ni, 90Zr, 120Sn and 208Pb excited by means of the (α, 3He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in 91Zr, and between 8 and 12 MeV excitation energy in 209Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations.
Nuclear charge and magnetization densities of single particle states
International Nuclear Information System (INIS)
Frois, B.
1985-01-01
High energy electron scattering data have recently determined the spatial distributions of nucleons in the center of nuclei with amazing accuracy. For the first time we have access to the structure of the nuclear interior throughout the periodic table. The spatial resolution achieved by high momentum transfer measurements is now sufficient to define clearly the present limits of nuclear theory. The experimental situation is briefly reviewed and the results interpreted in the framework of self-consistent field theory. The shapes of single particle distributions in the nuclear interior are found to be in surprisingly good agreement with the predictions of mean field theory. The effects of correlations are discussed. (orig.)
Real stabilization method for nuclear single-particle resonances
International Nuclear Information System (INIS)
Zhang Li; Zhou Shangui; Meng Jie; Zhao Enguang
2008-01-01
We develop the real stabilization method within the framework of the relativistic mean-field (RMF) model. With the self-consistent nuclear potentials from the RMF model, the real stabilization method is used to study single-particle resonant states in spherical nuclei. As examples, the energies, widths, and wave functions of low-lying neutron resonant states in 120 Sn are obtained. These results are compared with those from the scattering phase-shift method and the analytic continuation in the coupling constant approach and satisfactory agreements are found
Nuclear charge and magnetization densities of single particle states
International Nuclear Information System (INIS)
Frois, B.
1985-05-01
High energy electron scattering data have recently determined the spatial distributions of nucleons in the center of nuclei with amazing accuracy. For the first time we have access to the structure of the nuclear interior throughout the periodic table. The spatial resolution achieved by high momentum transfer measurements is now sufficient to define clearly the present limits of nuclear theory. The experimental situation is briefly reviewed and the results interpreted in the framework of self-consistent field theory. The shapes of single particle distributions in the nuclear interior are found to be in surprisingly good agreement with the predictions of mean field theory. The effects of correlations are discussed
The measurement of single particle temperature in plasma sprays
International Nuclear Information System (INIS)
Fincke, J.R.; Swank, W.D.; Bolsaitis, P.P.; Elliott, J.F.
1990-01-01
A measurement technique for simultaneously obtaining the size, velocity, temperature, and relative number density of particles entrained in high temperature flow fields is described. In determining the particle temperature from a two-color pyrometery technique, assumptions about the relative spectral emissivity of the particle are required. For situations in which the particle surface undergoes chemical reactions the assumption of grey body behavior is shown to introduce large Temperature measurement uncertainties. Results from isolated, laser heated, single particle measurements and in-flight data from the plasma spraying of WC-Co are presented. 10 refs., 5 figs
Komninos, Yannis; Mercouris, Theodoros; Nicolaides, Cleanthes A.
2014-01-01
In continuation of our earlier works, we present results concerning the computation of matrix elements of the multipolar Hamiltonian (MPH) between extended wave functions that are obtained numerically. The choice of the MPH is discussed in connection with the broader issue of the form of radiation-atom (or -molecule) interaction that is appropriate for the systematic solution of various problems of matter-radiation interaction. We derive analytic formulas, in terms of the sine-integral function and spherical Bessel functions of various orders, for the cumulative radial integrals that were obtained and calculated by Komninos, Mercouris, and Nicolaides [Phys. Rev. A 71, 023410 (2005), 10.1103/PhysRevA.71.023410]. This development allows the much faster and more accurate computation of such matrix elements, a fact that enhances the efficiency with which the time-dependent Schrödinger equation is solved nonperturbatively, in the framework of the state-specific expansion approach. The formulas are applicable to the general case where a pair of orbitals with angular parts |ℓ1,m1> and |ℓ2,m2> are coupled radiatively. As a test case, we calculate the matrix elements of the electric field and of the paramagnetic operators for on- and off-resonance transitions, between hydrogenic circular states of high angular momentum, whose quantum numbers are chosen so as to satisfy electric dipole and electric quadrupole selection rules. Because of the nature of their wave function (they are nodeless and the large centrifugal barrier keeps their overwhelming part at large distances from the nucleus), the validity of the electric dipole approximation in various applications where the off-resonance couplings must be considered becomes precarious. For example, for the transition from the circular state with n = 20 to that with n = 21, for which ≈400 a.u., the dipole approximation starts to fail already at XUV wavelengths (λ <125nm).
Kaon matrix elements and CP violation from quenched lattice QCD: The 3-flavor case
International Nuclear Information System (INIS)
Blum, T.; Wingate, M.; Chen, P.; Christ, N.; Cristian, C.; Fleming, G.; Mawhinney, R.; Siegert, G.; Wu, L.; Zhestkov, Y.; Dawson, C.; Soni, A.; Ohta, S.; Vranas, P.
2003-01-01
We report the results of a calculation of the K→ππ matrix elements relevant for the ΔI=1/2 rule and ε ' /ε in quenched lattice QCD using domain wall fermions at a fixed lattice spacing a -1 ∼2 GeV. Working in the three-quark effective theory, where only the u, d, and s quarks enter and which is known perturbatively to next-to-leading order, we calculate the lattice K→π and K→|0> matrix elements of dimension six, four-fermion operators. Through lowest order chiral perturbation theory these yield K→ππ matrix elements, which we then normalize to continuum values through a nonperturbative renormalization technique. For the ratio of isospin amplitudes vertical bar A 0 vertical bar/vertical bar A 2 vertical bar we find a value of 25.3±1.8 (statistical error only) compared to the experimental value of 22.2, with individual isospin amplitudes 10%-20% below the experimental values. For ε ' /ε, using known central values for standard model parameters, we calculate (-4.0±2.3)x10 -4 (statistical error only) compared to the current experimental average of (17.2±1.8)x10 -4 . Because we find a large cancellation between the I=0 and I=2 contributions to ε ' /ε, the result may be very sensitive to the approximations employed. Among these are the use of quenched QCD, lowest order chiral perturbation theory, and continuum perturbation theory below 1.3 GeV. We also calculate the kaon B parameter B K and find B K,MS (2 GeV)=0.532(11). Although currently unable to give a reliable systematic error, we have control over statistical errors and more simulations will yield information about the effects of the approximations on this first-principles determination of these important quantities
Measurement of the CKM matrix element vertical stroke Vts vertical stroke 2
International Nuclear Information System (INIS)
Unverdorben, Christopher Gerhard
2015-03-01
This is the first direct measurement of the CKM matrix element vertical stroke V ts vertical stroke, using data collected by the ATLAS detector in 2012 at √(s)= 8 TeV pp-collisions with a total integrated luminosity of 20.3 fb -1 . The analysis is based on 112 171 reconstructed t anti t candidate events in the lepton+jets channel, having a purity of 90.0 %. 183 t anti t→W + W - b anti s decays are expected (charge conjugation implied), which are available for the extraction of the CKM matrix element vertical stroke V ts vertical stroke 2 . To identify these rare decays, several observables are examined, such as the properties of jets, tracks and of b-quark identification algorithms. Furthermore, the s-quark hadrons K 0 s are considered, reconstructed by a kinematic fit. The best observables are combined in a multivariate analysis, called ''boosted decision trees''. The responses from Monte Carlo simulations are used as templates for a fit to data events yielding a significance value of 0.7σ for t→s+W decays. An upper limit of vertical stroke V ts vertical stroke 2 <1.74 % at 95 % confidence level is set, including all systematic and statistical uncertainties. So this analysis, using a direct measurement of the CKM matrix element vertical stroke V ts vertical stroke 2 , provides the best direct limit on vertical stroke V ts vertical stroke 2 up to now.
Structure of the two-neutrino double-β decay matrix elements within perturbation theory
Štefánik, Dušan; Šimkovic, Fedor; Faessler, Amand
2015-06-01
The two-neutrino double-β Gamow-Teller and Fermi transitions are studied within an exactly solvable model, which allows a violation of both spin-isospin SU(4) and isospin SU(2) symmetries, and is expressed with generators of the SO(8) group. It is found that this model reproduces the main features of realistic calculation within the quasiparticle random-phase approximation with isospin symmetry restoration concerning the dependence of the two-neutrino double-β decay matrix elements on isovector and isoscalar particle-particle interactions. By using perturbation theory an explicit dependence of the two-neutrino double-β decay matrix elements on the like-nucleon pairing, particle-particle T =0 and T =1 , and particle-hole proton-neutron interactions is obtained. It is found that double-β decay matrix elements do not depend on the mean field part of Hamiltonian and that they are governed by a weak violation of both SU(2) and SU(4) symmetries by the particle-particle interaction of Hamiltonian. It is pointed out that there is a dominance of two-neutrino double-β decay transition through a single state of intermediate nucleus. The energy position of this state relative to energies of initial and final ground states is given by a combination of strengths of residual interactions. Further, energy-weighted Fermi and Gamow-Teller sum rules connecting Δ Z =2 nuclei are discussed. It is proposed that these sum rules can be used to study the residual interactions of the nuclear Hamiltonian, which are relevant for charge-changing nuclear transitions.
Relativistic atomic matrix elements of rq for arbitrary states in the quantum-defect approximation
International Nuclear Information System (INIS)
Owono Owono, L.C.; Owona Angue, M.L.C.; Kwato Njock, M.G.; Oumarou, B.
2004-01-01
Recurrence relations used in the calculation of matrix elements of r q for arbitrary q and states of the relativistic one-electron atom with a point-like ionic core are obtained with Dirac and quasirelativistic effective radial Hamiltonians. The phenomenological and supersymmetry-inspired quantum-defect approaches introduced in previous works to model the electron-core interactions are employed. The formulas worked out on the basis of a hypervirial inspired method may be viewed as a generalization to off-diagonal cases of our recently reported results on the evaluation of expectation values of r q
Closed form for two-photon free-free transition matrix elements
Energy Technology Data Exchange (ETDEWEB)
Karule, Erna E-mail: karule@latnet.lv
2000-08-01
Two-photon free-free transitions happen in the multiphoton ionization with more than one excess photon and in Bremsstrahlung. Up to now, the configuration space free-free transition amplitudes have not been written in closed form. We propose a modified Coulomb Green's function (CGF) Sturm ian expansion which allows one to obtain expressions for two-photon radial transition matrix elements in the closed form which are easy to continue analytically to calculate free-free transitions in H.
Neutron-proton matrix element ratios of 21+ states in 58,60,62,64Ni
International Nuclear Information System (INIS)
Antalik, R.
1989-01-01
The neutron-proton matrix element ratios (η) for 2 1 + states of even Ni isotopes are investigated within the framework of the shell model quasiparticle random-phase approximation. The special attention is devoted to the dependence of η ratios on the radial neutron and proton ground-state density-distribution differences (Δ np ). This dependence is found to be about 0.5Δ np . The theoretical η ratios are 14-23% greater than the hydrodynamical limit. The theoretical Δ np dependence of η ratios enable us to understand the empirical η ratio results. 20 refs.; 2 figs.; 2 tabs
Number-conserving random phase approximation with analytically integrated matrix elements
International Nuclear Information System (INIS)
Kyotoku, M.; Schmid, K.W.; Gruemmer, F.; Faessler, A.
1990-01-01
In the present paper a number conserving random phase approximation is derived as a special case of the recently developed random phase approximation in general symmetry projected quasiparticle mean fields. All the occurring integrals induced by the number projection are performed analytically after writing the various overlap and energy matrices in the random phase approximation equation as polynomials in the gauge angle. In the limit of a large number of particles the well-known pairing vibration matrix elements are recovered. We also present a new analytically number projected variational equation for the number conserving pairing problem
Differential cross sections and spin density matrix elements for the reaction gamma p -> p omega
Energy Technology Data Exchange (ETDEWEB)
M. Williams, D. Applegate, M. Bellis, C.A. Meyer
2009-12-01
High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements.
Elimination of matrix effect in quantitative analysis of elements using x-ray fluorescence
International Nuclear Information System (INIS)
Sampaio, R.V.
1973-07-01
The emission-transmission method of Leroux and Mahmud, an experimental technique for compensating matrix effects in photon excited X-ray fluorescence analysis, was used to determine the concentration of lead and antimony in pellets of galalith. The effect of interfering elements was studied by adding various concentrations of mercury and tin to the respective pellets. To illustrate possible environmental applications, a number of pellets was prepared from leaves of almond trees located in different regions of Rio de Janeiro. Lead concentrations were determined for the dried leaf material and showed values ranging from 50 to 145 parts per million [pt
Spin Density Matrix Elements in exclusive production of ω mesons at Hermes
Directory of Open Access Journals (Sweden)
Marianski B.
2014-03-01
Full Text Available Spin density matrix elements have been determined for exclusive ω meson production on hydrogen and deuterium targets, in the kinematic region of 1.0 < Q2 < 10.0 GeV2, 3.0 < W < 6.3 GeV and –t' < 0.2 GeV2. The data, from which SDMEs are determined, were accumulated with the HERMES forward spectrometer during the running period of 1996 to 2007 using the 27.6 GeV electron or positron beam of HERA. A sizable contribution of unnatural parity exchange amplitudes is found for exclusive ω meson production.
The matrix element for radiative Bhabha scattering in the forward direction
International Nuclear Information System (INIS)
Kleiss, R.
1993-09-01
We present an approximation to the matrix element for the process e + e - →e + e - γ, appropriate to the situation where one or both of the fermions are scattered over very small angles. The leading terms in the situation where all scattering angles are small contains not only terms quadratic in the electron mass, but also quartic and even sextic terms must be included. Special attention is devoted to the numerical stability of the resultant expression. Its relation to several existing formulae is discussed. (orig.)
The O(αs3TF2) contributions to the gluonic operator matrix element
International Nuclear Information System (INIS)
Ablinger, J.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; Manteuffel, A. von; Round, M.; Schneider, C.
2014-01-01
The O(α s 3 T F 2 C F (C A )) contributions to the transition matrix element A gg,Q relevant for the variable flavor number scheme at 3-loop order are calculated. The corresponding graphs contain two massive fermion lines of equal mass leading to terms given by inverse binomially weighted sums beyond the usual harmonic sums. In x-space two root-valued letters contribute in the iterated integrals in addition to those forming the harmonic polylogarithms. We outline technical details needed in the calculation of graphs of this type, which are as well of importance in the case of two different internal massive lines
International Nuclear Information System (INIS)
Yoriyaz, H.
1986-01-01
In this work a spatial burnup scheme and feedback effects has been implemented into the FERM ( 'Finite Element Response Matrix' )program. The spatially dependent neutronic parameters have been considered in three levels: zonewise calculation, assembly wise calculation and pointwise calculation. Flux and power distributions and the multiplication factor were calculated and compared with the results obtained by CITATIOn program. These comparisons showed that processing time in the Ferm code has been hundred of times shorter and no significant difference has been observed in the assembly average power distribution. (Author) [pt
Matrix Elements of One- and Two-Body Operators in the Unitary Group Approach (I)-Formalism
Institute of Scientific and Technical Information of China (English)
DAI Lian-Rong; PAN Feng
2001-01-01
The tensor algebraic method is used to derive general one- and two-body operator matrix elements within the Un representations, which are useful in the unitary group approach to the configuration interaction problems of quantum many-body systems.
International Nuclear Information System (INIS)
Song Hong-qiu; Wang Zixing; Cai Yanhuang; Huang Weizhi
1987-01-01
The matrix elements of the M-3Y force are adopted as the equivalent G-matrix elements and the folded diagram method is used to calculate the spectra of 18 O and 18 F. The results show that the matrix elements of the M-3Y force as the equivalent G-matrix elements are suitable for microscopic calculations of the nuclei in the s-d shell
International Nuclear Information System (INIS)
Rousseau, P.
1968-01-01
In a first part, after a brief recall concerning 'planar' technology we discuss the various parasitic elements associated with integrated circuits components. Mathematical formulae of these elements are derived. In a second part, we present a matrix of 22 transistors and 12 resistors which has been realized. This matrix enables the integration of the major part of nuclear circuits. Some of the obtained circuits are shown, particularly an emitter coupled logic gate which presents good electrical behaviour. (author) [fr
Energy Technology Data Exchange (ETDEWEB)
Belavin, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky Avenue 53, 119991 Moscow (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, 127994 Moscow (Russian Federation); Moscow Institute of Physics and Technology,Dolgoprudnyi, 141700 Moscow region (Russian Federation); Cao, Xiangyu [LPTMS, CNRS (UMR 8626), Université Paris-Saclay,15 rue Georges Clémenceau, 91405 Orsay (France); Estienne, Benoit [LPTHE, CNRS and Université Pierre et Marie Curie, Sorbonne Universités,4 Place Jussieu, 75252 Paris Cedex 05 (France); Santachiara, Raoul [LPTMS, CNRS (UMR 8626), Université Paris-Saclay,15 rue Georges Clémenceau, 91405 Orsay (France)
2017-03-02
In a recent study we considered W{sub 3} Toda 4-point functions that involve matrix elements of a primary field with the highest-weight in the adjoint representation of sl{sub 3}. We generalize this result by considering a semi-degenerate primary field, which has one null vector at level two. We obtain a sixth-order Fuchsian differential equation for the conformal blocks. We discuss the presence of multiplicities, the matrix elements and the fusion rules.
Massive 3-loop ladder diagrams for quarkonic local operator matrix elements
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes; Hasselhuhn, Alexander; Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [Technische Hochschule Aachen (Germany). Inst. fuer Theoretische Physik
2012-06-15
3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with {xi} element of {l_brace}1,1/2,2{r_brace} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q{sup 2} >> m{sup 2}.
Massive 3-loop ladder diagrams for quarkonic local operator matrix elements
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstrasse 69, A-4040 Linz (Austria); Bluemlein, Johannes, E-mail: johannes.bluemlein@desy.de [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Hasselhuhn, Alexander [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Klein, Sebastian [Research Institut fuer Theoretische Physik E, RWTH Aachen University, D-52056 Aachen (Germany); Schneider, Carsten [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstrasse 69, A-4040 Linz (Austria); Wissbrock, Fabian [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2012-11-01
3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with {xi} Element-Of {l_brace}1,1/2,2{r_brace} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q{sup 2} Much-Greater-Than m{sup 2}.
Single particle level density in a finite depth potential well
International Nuclear Information System (INIS)
Shlomo, S.; Kolomietz, V.M.; Dejbakhsh, H.
1997-01-01
We consider the single particle level density g(ε) of a realistic finite depth potential well, concentrating on the continuum (ε>0) region. We carry out quantum-mechanical calculations of the partial level density g l (ε), associated with a well-defined orbital angular momentum l≤40, using the phase-shift derivative method and the Greens-function method and compare the results with those obtained using the Thomas-Fermi approximation. We also numerically calculate g(ε) as a l sum of g l (ε) up to a certain value of scr(l) max ≤40 and determine the corresponding smooth level densities using the Strutinsky smoothing procedure. We demonstrate, in accordance with Levinson close-quote s theorem, that the partial contribution g l (ε) to the single particle level density from continuum states has positive and negative values. However, g(ε) is nonnegative. We also point out that this is not the case for an energy-dependent potential well. copyright 1997 The American Physical Society
Temperature dependence of single-particle properties in nuclear matter
International Nuclear Information System (INIS)
Zuo, W.; Lu, G.C.; Li, Z.H.; Lombardo, U.; Schulze, H.-J.
2006-01-01
The single-nucleon potential in hot nuclear matter is investigated in the framework of the Brueckner theory by adopting the realistic Argonne V 18 or Nijmegen 93 two-body nucleon-nucleon interaction supplemented by a microscopic three-body force. The rearrangement contribution to the single-particle potential induced by the ground state correlations is calculated in terms of the hole-line expansion of the mass operator and provides a significant repulsive contribution in the low-momentum region around and below the Fermi surface. Increasing temperature leads to a reduction of the effect, while increasing density makes it become stronger. The three-body force suppresses somewhat the ground state correlations due to its strong short-range repulsion, increasing with density. Inclusion of the three-body force contribution results in a quite different temperature dependence of the single-particle potential at high enough densities as compared to that adopting the pure two-body force. The effects of three-body force and ground state correlations on the nucleon effective mass are also discussed
New instrument for tribocharge measurement due to single particle impacts
International Nuclear Information System (INIS)
Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Ding Yulong; Pitt, Kendal G.
2007-01-01
During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10 fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as ∼100 μm impacting on the target at different incident angles with a velocity up to about 80 m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact
International Nuclear Information System (INIS)
Cheng Lan; Huang Weizhi; Zhou Baosen
1996-01-01
Using the matrix elements of M-3Y force as the equivalent G-matrix elements, the spectra of 210 Pb, 206 Pb, 206 Hg and 210 Po are calculated in the framework of the Folded Diagram Method. The results show that such equivalent matrix elements are suitable for microscopic calculations of the nuclear structure in heavy mass region
Measurement of single top quark production at D0 using a matrix element method
International Nuclear Information System (INIS)
Mitrevski, Jovan Pavle
2007-01-01
Until now, the top quark has only been observed produced in pairs, by the strong force. According to the standard model, it can also be produced singly, via an electroweak interaction. Top quarks produced this way provide powerful ways to test the charged-current electroweak interactions of the top quark, to measure |V tb |, and to search for physics beyond the standard model. This thesis describes the application of the matrix element analysis technique to the search for single top quark production with the D0 detector using 0.9 fb -1 of Run II data. From a comparison of the matrix element discriminants between data and the background model, assuming a Standard Model s-channel to t-channel cross section ratio of σ s /σ t = 0.44, we measure the single top quark production cross section: σ(p(bar p) → tb + X, tqb + X) = 4.8 -1.4 +1.6 pb. This result has a p-value of 0.08%, corresponding to a 3.2 standard deviation Gaussian equivalent significance
Diagrammatic technique for calculating matrix elements of collective operators in superradiance
International Nuclear Information System (INIS)
Lee, C.T.
1975-01-01
Adopting the so-called ''genealogical construction,'' one can express the eigenstates of collective operators corresponding to a specified mode for an N-atom system in terms of those for an (N-1) -atom system. Using these Dicke states as bases and using the Wigner-Eckart theorem, a matrix element of a collective operator of an arbitrary mode can be written as the product of an m-dependent factor and an m-independent reduced matrix element (RME). A set of recursion formulas for the RME is obtained. A graphical representation of the RME on the branching diagram for binary irreducible representations of permutation groups is then introduced. This gives a simple and systematic way of calculating the RME. This method is especially useful when the cooperation number r is close to N/2, where almost exact asymptotic expressions can be obtained easily. The result shows explicitly the geometry dependence of superradiance and the relative importance of r-conserving and r-nonconserving processes. This clears up the chief difficulty encountered in the Dicke-Schwendimann approach to the problem of N two-level atoms, spread over large regions, interacting with a multimode radiation field
Reorientation-effect measurement of the matrix element in 10Be
Orce, J. N.; Drake, T. E.; Djongolov, M. K.; Navrátil, P.; Triambak, S.; Ball, G. C.; Al Falou, H.; Churchman, R.; Cross, D. S.; Finlay, P.; Forssén, C.; Garnsworthy, A. B.; Garrett, P. E.; Hackman, G.; Hayes, A. B.; Kshetri, R.; Lassen, J.; Leach, K. G.; Li, R.; Meissner, J.; Pearson, C. J.; Rand, E. T.; Sarazin, F.; Sjue, S. K. L.; Stoyer, M. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Tardiff, E. R.; Teigelhoefer, A.; Williams, S. J.; Wong, J.; Wu, C. Y.
2012-10-01
The highly-efficient and segmented TIGRESS γ-ray spectrometer at TRIUMF has been used to perform a reorientation-effect Coulomb-excitation study of the 21+ state at 3.368 MeV in 10Be. This is the first Coulomb-excitation measurement that enables one to obtain information on diagonal matrix elements for such a high-lying first excited state from γ-ray data. With the availability of accurate lifetime data, a value of -0.110±0.087 eb is determined for the diagonal matrix element, which assuming the rotor model, leads to a negative spectroscopic quadrupole moment of QS(21+)=-0.083±0.066 eb. This result is in agreement with both no-core shell-model calculations performed in this work with the CD-Bonn 2000 two-nucleon potential and large shell-model spaces, and Green's function Monte Carlo predictions with two- plus three-nucleon potentials.
A new program for calculating matrix elements of one-particle operators in jj-coupling
International Nuclear Information System (INIS)
Pyper, N.C.; Grant, I.P.; Beatham, N.
1978-01-01
The aim of this paper is to calculate the matrix elements of one-particle tensor operators occurring in atomic and nuclear theory between configuration state functions representing states containing any number of open shells in jj-coupling. The program calculates the angular part of these matrix elements. The program is essentially a new version of RDMEJJ, written by J.J. Chang. The aims of this version are to eliminate inconsistencies from RDMEJJ, to modify its input requirements for consistency with MCP75, and to modify its output so that it can be stored in a discfile for access by other compatible programs. The program assumes that the configurational states are built from a common orthonormal set of basis orbitals. The number of electrons in a shell having j>=9/2 is restricted to be not greater than 2 by the available CFP routines . The present version allows up to 40 orbitals and 50 configurational states with <=10 open shells; these numbers can be changed by recompiling with modified COMMON/DIMENSION statements. The user should ensure that the CPC library subprograms AAGD, ACRI incorporate all current updates and have been converted to use double precision floating point arithmetic. (Auth.)
An experimentalist's guide to the matrix element in angle resolved photoemission
International Nuclear Information System (INIS)
Moser, Simon
2017-01-01
Highlights: • An introduction to the art of angle resolved photoemission is presented. • Matrix element effects are described by a nearly free electron final state model. • ARPES spectral weight of a Bloch band can be calculated from the Fourier transform of its Wannier orbital. • Experimental handedness and improper polarization introduce dichroism. • Instructive showcases from modern ARPES are discussed in detail. - Abstract: Angle resolved photoemission spectroscopy (ARPES) is commonly known as a powerful probe of the one-electron removal spectral function in ordered solid state. With increasing efficiency of light sources and spectrometers, experiments over a wide range of emission angles become more and more common. Consequently, the angular variation of ARPES spectral weight – often times termed “matrix element effect” – enters as an additional source of information. In this tutorial, we develop a simple but instructive free electron final state approach based on the three-step model to describe the intensity distribution in ARPES. We find a compact expression showing that the ARPES spectral weight of a given Bloch band is essentially determined by the momentum distribution (the Fourier transform) of its associated Wannier orbital – times a polarization dependent pre-factor. While the former is giving direct information on the symmetry and shape of the electronic wave function, the latter can give rise to surprising geometric effects. We discuss a variety of modern and instructive experimental showcases for which this simplistic formalism works astonishingly well and discuss the limits of this approach.
Precision Measurement of the Neutron Twist-3 Matrix Element dn2: Probing Color Forces
Energy Technology Data Exchange (ETDEWEB)
Posik, Matthew; Flay, David; Parno, Diana; Allada, Kalyan; Armstrong, Whitney; Averett, Todd; Benmokhtar, Fatiha; Bertozzi, William; Camsonne, Alexandre; Canan, Mustafa; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cusanno, Francesco; Dalton, Mark; Deconinck, Wouter; De Jager, Cornelis; Deng, Xiaoyan; Deur, Alexandre; Dutta, Chiranjib; El Fassi, Lamiaa; Franklin, Gregg; Friend, Megan; Gao, Haiyan; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Golge, Serkan; Gomez, Javier; Guo, Lei; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, J; Hyde, Charles; Ibrahim Abdalla, Hassan; Jiang, Xiaodong; Jin, Ge; Katich, Joseph; Kelleher, Aidan; Kolarkar, Ameya; Korsch, Wolfgang; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Long, Elena; Lukhanin, Oleksandr; Mamyan, Vahe; McNulty, Dustin; Meziani, Zein-Eddine; Michaels, Robert; Mihovilovic, Miha; Moffit, Bryan; Muangma, Navaphon; Nanda, Sirish; Narayan, Amrendra; Nelyubin, Vladimir; Norum, Blaine; Nuruzzaman, nfn; Oh, Yongseok; Peng, Jen-chieh; Qian, Xin; Qiang, Yi; Rakhman, Abdurahim; Riordan, Seamus; Saha, Arunava; Sawatzky, Bradley; Hashemi Shabestari, Mitra; Shahinyan, Albert; Sirca, Simon; Solvignon-Slifer, Patricia; Subedi, Ramesh; Sulkosky, Vincent; Tobias, William; Troth, Wolfgang; Wang, Diancheng; Wang, Y; Wojtsekhowski, Bogdan; Yan, X; Yao, Huan; Ye, Yunxiu; Ye, Zhihong; Yuan, Lulin; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, Bo; Zheng, Xiaochao
2014-07-01
Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25 lte x lte 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized 3He target. In this dedicated experiment, the spin structure function g2 on 3He was determined with precision at large x, and the neutron twist-three matrix element dn2 was measured at ?Q2? of 3.21 and 4.32 GeV2/c2, with an absolute precision of about 10?5. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at ?Q2?= 5 GeV2/c2. Combining dn2 and a newly extracted twist-four matrix element, fn2, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 60 MeV/fm in magnitude.
Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements
International Nuclear Information System (INIS)
Faessler, Amand
2005-01-01
The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters
An experimentalist's guide to the matrix element in angle resolved photoemission
Energy Technology Data Exchange (ETDEWEB)
Moser, Simon, E-mail: skmoser@lbl.gov [Advanced Light Source (ALS), Berkeley, CA 94720 (United States); Institute of Physics (IPHYS), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)
2017-01-15
Highlights: • An introduction to the art of angle resolved photoemission is presented. • Matrix element effects are described by a nearly free electron final state model. • ARPES spectral weight of a Bloch band can be calculated from the Fourier transform of its Wannier orbital. • Experimental handedness and improper polarization introduce dichroism. • Instructive showcases from modern ARPES are discussed in detail. - Abstract: Angle resolved photoemission spectroscopy (ARPES) is commonly known as a powerful probe of the one-electron removal spectral function in ordered solid state. With increasing efficiency of light sources and spectrometers, experiments over a wide range of emission angles become more and more common. Consequently, the angular variation of ARPES spectral weight – often times termed “matrix element effect” – enters as an additional source of information. In this tutorial, we develop a simple but instructive free electron final state approach based on the three-step model to describe the intensity distribution in ARPES. We find a compact expression showing that the ARPES spectral weight of a given Bloch band is essentially determined by the momentum distribution (the Fourier transform) of its associated Wannier orbital – times a polarization dependent pre-factor. While the former is giving direct information on the symmetry and shape of the electronic wave function, the latter can give rise to surprising geometric effects. We discuss a variety of modern and instructive experimental showcases for which this simplistic formalism works astonishingly well and discuss the limits of this approach.
Three loop contributions to the matrix elements in the variable flavor number scheme
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, Johannes; Hasselhuhn, Alexander [DESY (Germany); Schneider, Carsten [RISC, JKU Linz (Austria)
2012-07-01
The variable flavor number scheme may be used to describe parton distributions in the transition region in which one heavy quark gradually becomes a light flavor. We present first three-loop results to the massive operator matrix elements A{sub gg} and A{sub gq} for the contributions due to bubble topologies {proportional_to}T{sub F}{sup 2} n{sub f} at general values of the Mellin variable N. The calculation has been performed using higher transcendental functions and by applying modern summation technologies encoded in the package Sigma. These massive operator matrix elements describe the universal contributions in the matching of different flavor sectors, which are the logarithmic and constant contributions in the ratio of m{sup 2}{sub H}/Q{sup 2}, with Q{sup 2} the virtuality and m{sub H} the respective heavy quark mass. The framework allows to derive heavy quark parton distributions which are of relevance for calculating specific processes at hadron-hadron colliders.
Measurement of the top quark mass in the dilepton final state using the matrix element method
Energy Technology Data Exchange (ETDEWEB)
Grohsjean, Alexander [Ludwig Maximilian Univ., Munich (Germany)
2008-12-15
The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb^{-1}. A total of 107 t$\\bar{t}$ candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m_{top}^{Run IIa} = 170.6 ± 6.1(stat.)_{-1.5}^{+2.1}(syst.)GeV; m_{top}^{Run IIb} = 174.1 ± 4.4(stat.)_{-1.8}^{+2.5}(syst.)GeV; m
Choice of single-particle potential and the convergence of the effective interaction
International Nuclear Information System (INIS)
Hjorth-Jensen, M.; Osnes, E.; Muether, H.; Schmid, K.W.
1990-02-01
The convergence of the expansion for the effective interaction is studied considering as example the shell model for the nuclei 18 O and 18 F. In this work the effective interaction is computed through third order in the Brueckner G matrix, using both a harmonic-oscillator (HO) basis and a Brueckner-Hartree-Fock (BHF) basis. The significant differences in the convergence behavior of the effective interaction in these two cases are reported. The results indicate that the choice of the BHF single-particle potential facilitates the convergence of the effective interaction in low-orders of the expansion, whereas the HO results exhibit a non-convergent behavior. The implications for the HO approach are discussed. All calculations have been performed considering a modern version of the Bonn one-boson-exchange potential for the nucleon-nucleon interaction. 23 refs., 4 figs., 2 tabs
International Nuclear Information System (INIS)
Matsuda, Koichi; Nishiura, Hiroyuki
2004-01-01
We reanalyze the mass matrix model of quarks and leptons that gives a unified description of quark and lepton mass matrices with the same texture form. By investigating possible types of assignment for the texture components of the lepton mass matrix, we find that a different assignment for neutrinos than for charged leptons can also lead to consistent values of the Maki-Nakagawa-Sakata-Pontecorv (MNSP) lepton mixing matrix. We also find that the predicted value for the lepton mixing matrix element U 13 of the model depends on the assignment. A proper assignment will be discriminated by future experimental data for U 13
Single top quark production and Vtb CKM matrix element measurement in high energy e+e- collisions
International Nuclear Information System (INIS)
Dokholyan, N.V.; Jikia, G.V.
1993-01-01
The new method of determination of CKM mixing matrix element V tb has been proposed. It has been shown, that at the future colliders one will measure the tb-mixing element with the accuracy 12 - 28%. 16 refs., 6 figs., 1 tab
Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad
2011-01-01
A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…
Study on the fragmentation of granite due to the impact of single particle and double particles
Directory of Open Access Journals (Sweden)
Yuchun Kuang
2016-09-01
Full Text Available Particle Impact Drilling (PID is a novel method to improve the rate of penetration (ROP. In order to further improve the performance of PID, an investigation into the effect of single and double particles: (1 diameter; (2 initial velocity; (3 distance; and (4 angle of incidence was undertaken to investigate their effects on broken volume and penetration depth into hard brittle rock. For this purpose, the laboratory experiment of single particle impact rock was employed. Meanwhile, based on the LS-DYNA, a new finite element (FE simulation of the PID, including single and double particles impact rock, has been presented. The 3-dimensional (3D, aix-symmetric, dynamic-explicit, Lagrangian model has been considered in this simulation. And the Elastic and Holmquist Johnson Cook (HJC material behaviors have been used for particles and rocks, respectively. The FE simulation results of single particle impacting rock are good agreement with experimental data. Furthermore, in this article the optimal impact parameters, including diameter, initial velocity, distance and the angle of incidence, are obtained in PID.
Optimization of magnetic switches for single particle and cell transport
Energy Technology Data Exchange (ETDEWEB)
Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, North Carolina 27708 (United States); Joint Institute, University of Michigan—Shanghai Jiao Tong University, Shanghai Jiao Tong University, Shanghai 200240 (China); Murdoch, David M. [Department of Medicine, Duke University, Durham, North Carolina 27708 (United States); Kim, CheolGi [Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 711-873 (Korea, Republic of)
2014-06-28
The ability to manipulate an ensemble of single particles and cells is a key aim of lab-on-a-chip research; however, the control mechanisms must be optimized for minimal power consumption to enable future large-scale implementation. Recently, we demonstrated a matter transport platform, which uses overlaid patterns of magnetic films and metallic current lines to control magnetic particles and magnetic-nanoparticle-labeled cells; however, we have made no prior attempts to optimize the device geometry and power consumption. Here, we provide an optimization analysis of particle-switching devices based on stochastic variation in the particle's size and magnetic content. These results are immediately applicable to the design of robust, multiplexed platforms capable of transporting, sorting, and storing single cells in large arrays with low power and high efficiency.
Reconstructing an icosahedral virus from single-particle diffraction experiments
Saldin, D. K.; Poon, H.-C.; Schwander, P.; Uddin, M.; Schmidt, M.
2011-08-01
The first experimental data from single-particle scattering experiments from free electron lasers (FELs) are now becoming available. The first such experiments are being performed on relatively large objects such as viruses, which produce relatively low-resolution, low-noise diffraction patterns in so-called ``diffract-and-destroy'' experiments. We describe a very simple test on the angular correlations of measured diffraction data to determine if the scattering is from an icosahedral particle. If this is confirmed, the efficient algorithm proposed can then combine diffraction data from multiple shots of particles in random unknown orientations to generate a full 3D image of the icosahedral particle. We demonstrate this with a simulation for the satellite tobacco necrosis virus (STNV), the atomic coordinates of whose asymmetric unit is given in Protein Data Bank entry 2BUK.
Decay properties of high-lying single-particles modes
Energy Technology Data Exchange (ETDEWEB)
Beaumel, D. [Institut de Physique Nucleaire, 91 - Orsay (France); Fortier, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Gales, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Guillot, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Langevin-Joliot, H. [Institut de Physique Nucleaire, 91 - Orsay (France); Laurent, H. [Institut de Physique Nucleaire, 91 -Orsay (France); Maison, J.M. [Institut de Physique Nucleaire, 91 - Orsay (France); Vernotte, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Bordewijck, J. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Brandenburg, S. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Krasznahorkay, A. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Crawley, G.M. [NSCL, Michigan State University, East Lansing, MI 48824 (United States); Massolo, C.P. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Renteria, M. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Khendriche, A. [University of Tizi-Ouzou, Tizi-Ouzou (Algeria)
1996-03-18
The neutron decay of high-lying single-particle states in {sup 64}Ni, {sup 90}Zr, {sup 120}Sn and {sup 208}Pb excited by means of the ({alpha},{sup 3}He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in {sup 91}Zr, and between 8 and 12 MeV excitation energy in {sup 209}Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations. (orig.).
Towards single particle imaging of human chromosomes at SACLA
International Nuclear Information System (INIS)
Robinson, Ian; Schwenke, Joerg; Yusuf, Mohammed; Estandarte, Ana; Zhang, Fucai; Chen, Bo; Clark, Jesse; Song, Changyong; Nam, Daewoong; Joti, Yasumasa; Tono, Kensuke; Yabashi, Makina; Ratnasari, Gina; Kaneyoshi, Kohei; Takata, Hideaki; Fukui, Kiichi
2015-01-01
Single particle imaging (SPI) is one of the front-page opportunities which were used to motivate the construction of the first x-ray free electron lasers (XFELs). SPI’s big advantage is that it avoids radiation damage to biological samples because the diffraction takes place in femtosecond single shots before any atomic motion can take place in the sample, hence before the onset of radiation damage. This is the ‘diffract before destruction’ theme, destruction being assured from the high x-ray doses used. This article reports our collaboration’s first attempt at SPI using the SACLA XFEL facility in June 2015. The report is limited to experience with the instrumentation and examples of data because we have not yet had time to invert them to images. (paper)
Authenticated multi-user quantum key distribution with single particles
Lin, Song; Wang, Hui; Guo, Gong-De; Ye, Guo-Hua; Du, Hong-Zhen; Liu, Xiao-Fen
2016-03-01
Quantum key distribution (QKD) has been growing rapidly in recent years and becomes one of the hottest issues in quantum information science. During the implementation of QKD on a network, identity authentication has been one main problem. In this paper, an efficient authenticated multi-user quantum key distribution (MQKD) protocol with single particles is proposed. In this protocol, any two users on a quantum network can perform mutual authentication and share a secure session key with the assistance of a semi-honest center. Meanwhile, the particles, which are used as quantum information carriers, are not required to be stored, therefore the proposed protocol is feasible with current technology. Finally, security analysis shows that this protocol is secure in theory.
A transient single particle model under FCI conditions
Institute of Scientific and Technical Information of China (English)
LI Xiao-Yan; SHANG Zhi; XU Ji-Jun
2005-01-01
The paper is focused on the coupling effect between film boiling heat transfer and evaporation drag around a hot-particle in cold liquid. Based on the continuity, momentum and energy equations of the vapor film, a transient two-dimensional single particle model has been established. This paper contains a detailed description of HPMC (High-temperature Particle Moving in Coolant) model for studying some aspects of the premixing stage of fuel-coolant interactions (FCIs). The transient process of high-temperature particles moving in coolant can be simulated. Comparisons between the experiment results and the calculations using HPMC model demonstrate that HPMC model achieves a good agreement in predicting the time-varying characteristic of high-temperature spheres moving in coolant.
Classification using diffraction patterns for single-particle analysis
Energy Technology Data Exchange (ETDEWEB)
Hu, Hongli; Zhang, Kaiming [Department of Biophysics, the Health Science Centre, Peking University, Beijing 100191 (China); Meng, Xing, E-mail: xmeng101@gmail.com [Wadsworth Centre, New York State Department of Health, Albany, New York 12201 (United States)
2016-05-15
An alternative method has been assessed; diffraction patterns derived from the single particle data set were used to perform the first round of classification in creating the initial averages for proteins data with symmetrical morphology. The test protein set was a collection of Caenorhabditis elegans small heat shock protein 17 obtained by Cryo EM, which has a tetrahedral (12-fold) symmetry. It is demonstrated that the initial classification on diffraction patterns is workable as well as the real-space classification that is based on the phase contrast. The test results show that the information from diffraction patterns has the enough details to make the initial model faithful. The potential advantage using the alternative method is twofold, the ability to handle the sets with poor signal/noise or/and that break the symmetry properties. - Highlights: • New classification method. • Create the accurate initial model. • Better in handling noisy data.
Classification using diffraction patterns for single-particle analysis
International Nuclear Information System (INIS)
Hu, Hongli; Zhang, Kaiming; Meng, Xing
2016-01-01
An alternative method has been assessed; diffraction patterns derived from the single particle data set were used to perform the first round of classification in creating the initial averages for proteins data with symmetrical morphology. The test protein set was a collection of Caenorhabditis elegans small heat shock protein 17 obtained by Cryo EM, which has a tetrahedral (12-fold) symmetry. It is demonstrated that the initial classification on diffraction patterns is workable as well as the real-space classification that is based on the phase contrast. The test results show that the information from diffraction patterns has the enough details to make the initial model faithful. The potential advantage using the alternative method is twofold, the ability to handle the sets with poor signal/noise or/and that break the symmetry properties. - Highlights: • New classification method. • Create the accurate initial model. • Better in handling noisy data.
Multi-Color Single Particle Tracking with Quantum Dots
DEFF Research Database (Denmark)
Christensen, Eva Arnspang; Brewer, J. R.; Lagerholm, B. C.
2012-01-01
. multiplex single molecule sensitivity applications such as single particle tracking (SPT). In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations......Quantum dots (QDs) have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g...... further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC)-SPT with QDs is possible at an image...
Single particle analysis with a 3600 light scattering photometer
International Nuclear Information System (INIS)
Bartholdi, M.F.
1979-06-01
Light scattering by single spherical homogeneous particles in the diameter range 1 to 20 μm and relative refractive index 1.20 is measured. Particle size of narrowly dispersed populations is determined and a multi-modal dispersion of five components is completely analyzed. A 360 0 light scattering photometer for analysis of single particles has been designed and developed. A fluid stream containing single particles intersects a focused laser beam at the primary focal point of an ellipsoidal reflector ring. The light scattered at angles theta = 2.5 0 to 177.5 0 at phi = 0 0 and 180 0 is reflected onto a circular array of photodiodes. The ellipsoidal reflector is situated in a chamber filled with fluid matching that of the stream to minimize refracting and reflecting interfaces. The detector array consists of 60 photodiodes each subtending 3 0 in scattering angle on 6 0 centers around 360 0 . 32 measurements on individual particles can be acquired at rates of 500 particles per second. The intensity and angular distribution of light scattered by spherical particles are indicative of size and relative refractive index. Calculations, using Lorenz--Mie theory, of differential scattering patterns integrated over angle corresponding to the detector geometry determined the instrument response to particle size. From this the expected resolution and experimental procedures are determined.Ultimately, the photometer will be utilized for identification and discrimination of biological cells based on the sensitivity of light scattering to size, shape, refractive index differences, internal granularity, and other internal morphology. This study has demonstrated the utility of the photometer and indicates potential for application to light scattering studies of biological cells
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
International Nuclear Information System (INIS)
Ablinger, Jakob; Schneider, Carsten; Bluemlein, Johannes; Raab, Clemens; Wissbrock, Fabian
2014-02-01
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version to the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∝30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N element of C. Integrals with a power-like divergence in N-space∝a N , a element of R, a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Reserach Inst. for Symbolic Computation (RISC); Bluemlein, Johannes; Raab, Clemens [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Reserach Inst. for Symbolic Computation (RISC)
2014-02-15
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version to the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∝30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N element of C. Integrals with a power-like divergence in N-space∝a{sup N}, a element of R, a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Matrix elements for the anti B{yields}X{sub s}{gamma} decay at NNLO
Energy Technology Data Exchange (ETDEWEB)
Schutzmeier, Thomas Paul
2009-12-17
In the context of the indirect search for non-standard physics in the flavour sector of the Standard Model (SM), one of the most interesting processes is the rare inclusive anti B{yields} X{sub s}{gamma} decay. On the one hand, being a flavour-changing neutral current, this B decay is sensitive to new physics, as it is loop-suppressed in the SM. On the other hand, it is only mildly affected by non-perturbative effects, and thus allows for precise theoretical predictions in the framework of renormalization-group improved perturbation theory. Accurate measurements as well as precise theoretical predictions with a good control over both perturbative and non-perturbative contributions have to be provided in order to derive stringent constraints on the parameter space of physics beyond the SM. On the experimental side, an outstanding accuracy in the measurement of the anti B{yields}X{sub s}{gamma} decay rate has been achieved, which is mainly due the specialized experiments BaBar and Belle at the so-called B factories. To match the small experimental uncertainty, higher order computations within an effective low-energy theory of the SM are mandatory. In fact, next-to-next-to-leading order (NNLO) QCD corrections are required to provide a prediction for the decay rate with the same precision as the measurement. The NNLO evaluation of the anti B{yields}X{sub s}{gamma} decay rate has been pursued by various groups over the last decade. The project was completed to a large extent and a first estimate at this level of perturbation theory was obtained in 2006. This prediction, however, lacks important contributions from yet unknown matrix elements, that were estimated from results which are only partially known to date. In this work, we provide a framework for the systematic study of the missing matrix elements at the NNLO. As main results of this thesis, we determine fermionic corrections to the charm quark mass dependent matrix elements of four-quark operators in the
Matrix elements for the anti B→Xsγ decay at NNLO
International Nuclear Information System (INIS)
Schutzmeier, Thomas Paul
2009-01-01
In the context of the indirect search for non-standard physics in the flavour sector of the Standard Model (SM), one of the most interesting processes is the rare inclusive anti B→ X s γ decay. On the one hand, being a flavour-changing neutral current, this B decay is sensitive to new physics, as it is loop-suppressed in the SM. On the other hand, it is only mildly affected by non-perturbative effects, and thus allows for precise theoretical predictions in the framework of renormalization-group improved perturbation theory. Accurate measurements as well as precise theoretical predictions with a good control over both perturbative and non-perturbative contributions have to be provided in order to derive stringent constraints on the parameter space of physics beyond the SM. On the experimental side, an outstanding accuracy in the measurement of the anti B→X s γ decay rate has been achieved, which is mainly due the specialized experiments BaBar and Belle at the so-called B factories. To match the small experimental uncertainty, higher order computations within an effective low-energy theory of the SM are mandatory. In fact, next-to-next-to-leading order (NNLO) QCD corrections are required to provide a prediction for the decay rate with the same precision as the measurement. The NNLO evaluation of the anti B→X s γ decay rate has been pursued by various groups over the last decade. The project was completed to a large extent and a first estimate at this level of perturbation theory was obtained in 2006. This prediction, however, lacks important contributions from yet unknown matrix elements, that were estimated from results which are only partially known to date. In this work, we provide a framework for the systematic study of the missing matrix elements at the NNLO. As main results of this thesis, we determine fermionic corrections to the charm quark mass dependent matrix elements of four-quark operators in the effective theory at NNLO. For the first time, the
Marsden, Nicholas A.; Flynn, Michael J.; Allan, James D.; Coe, Hugh
2018-01-01
Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS) is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI) followed by time-of-flight mass spectrometry (TOF-MS). Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.In this study, we introduce a novel technique that enables the differentiation of mineral phase in silicate mineral particles by ion formation mechanism measured from subtle changes in ion arrival times at the TOF-MS detector. Using a combination of peak area and peak centroid measurements, we show that the arrangement of the interstitial alkali metals in the crystal structure, an important property in silicate mineralogy, influences the ion arrival times of elemental and molecular ion species in the negative ion mass spectra. A classification scheme is presented that allowed for the differentiation of illite-smectite, kaolinite and feldspar minerals on a single-particle basis. Online analysis of mineral dust aerosol generated from clay mineral standards produced mineral fractions that are in agreement with bulk measurements reported by
Directory of Open Access Journals (Sweden)
N. A. Marsden
2018-01-01
Full Text Available Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase. Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is much longer than many atmospheric processes. Single-particle mass spectrometry (SPMS is an established technique for the online size-resolved measurement of particle composition by laser desorption ionisation (LDI followed by time-of-flight mass spectrometry (TOF-MS. Although non-quantitative, the technique is able to identify the presence of silicate minerals in airborne dust particles from markers of alkali metals and silicate molecular ions in the mass spectra. However, the differentiation of mineral phase in silicate particles by traditional mass spectral peak area measurements is not possible. This is because instrument function and matrix effects in the ionisation process result in variations in instrument response that are greater than the differences in composition between common mineral phases.In this study, we introduce a novel technique that enables the differentiation of mineral phase in silicate mineral particles by ion formation mechanism measured from subtle changes in ion arrival times at the TOF-MS detector. Using a combination of peak area and peak centroid measurements, we show that the arrangement of the interstitial alkali metals in the crystal structure, an important property in silicate mineralogy, influences the ion arrival times of elemental and molecular ion species in the negative ion mass spectra. A classification scheme is presented that allowed for the differentiation of illite–smectite, kaolinite and feldspar minerals on a single-particle basis. Online analysis of mineral dust aerosol generated from clay mineral standards produced mineral fractions that are in agreement with bulk
Measurement of the Top Quark Mass Using the Matrix Element Technique in Dilepton Final States
Abazov, Victor Mukhamedovich
2016-08-18
We present a measurement of the top quark mass in ppbar collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb-1. The matrix element technique is applied to ttbar events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton + jets final state of ttbar decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt = 173.93 +- 1.84 GeV.
Nucleon distribution apmlitudes and proton decay matrix elements on the lattice
Energy Technology Data Exchange (ETDEWEB)
Braun, Vladimir M.; Goeckeler, Meinulf [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, Roger [Edinburgh Univ. (GB). School of Physics] (and others)
2008-11-15
Baryon distribution amplitudes (DAs) are crucial for the theory of hard exclusive reactions. We present a calculation of the first few moments of the leading-twist nucleon DA within lattice QCD. In addition we deal with the normalization of the next-to-leading (twist-four) DAs. The matrix elements determining the latter quantities are also responsible for proton decay in Grand Unified Theories. Our lattice evaluation makes use of gauge field configurations generated with two flavors of clover fermions. The relevant operators are renormalized nonperturbatively with the final results given in the MS scheme. We find that the deviation of the leading-twist nucleon DA from its asymptotic form is less pronounced than sometimes claimed in the literature. (orig.)
International Nuclear Information System (INIS)
Faifman, M.P.; Strizh, T.A.; Armour, E.A.G.; Harston, M.R.
1996-01-01
The calculated resonant formation rates of the muonic molecules DDμ and DTμ are presented. The approach developed earlier for calculating the transition matrix elements in the dipole approximation has been extended to include the quadrupole terms in the multipole expansion of the interaction operator. The calculated dependence of the DTμ formation rates on the energies of the incident Tμ muonic atoms shows that the effect of including the quadrupole correction is to reduce the magnitude of the peak rates by about 20-30% at the different temperatures, compared to those calculated in the dipole approximation. The dependence on temperature for the DDμ formation rates is obtained with the differences between the presented and previous calculations being less than 5%. (orig.)
Two-loop massive operator matrix elements for unpolarized heavy flavor production to O({epsilon})
Energy Technology Data Exchange (ETDEWEB)
Bierenbaum, I.; Bluemlein, J.; Klein, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation
2008-02-15
We calculate the O({alpha}{sup 2}{sub s}) massive operator matrix elements for the twist-2 operators, which contribute to the heavy flavor Wilson coefficients in unpolarized deeply inelastic scattering in the region Q{sup 2}>>m{sup 2}, up to the O({epsilon}) contributions. These terms contribute through the renormalization of the O({alpha}{sup 3}{sub s}) heavy flavor Wilson coefficients of the structure function F{sub 2}(x,Q{sup 2}). The calculation has been performed using light-cone expansion techniques without using the integration-by-parts method. We represent the individual Feynman diagrams by generalized hypergeometric structures, the {epsilon}-expansion of which leads to infinite sums depending on the Mellin variable N. These sums are finally expressed in terms of nested harmonic sums using the general summation techniques implemented in the Sigma package. (orig.)
HELAC-Onia: an automatic matrix element generator for heavy quarkonium physics
Shao, Hua-Sheng
2013-01-01
By the virtues of the Dyson-Schwinger equations, we upgrade the published code \\mtt{HELAC} to be capable to calculate the heavy quarkonium helicity amplitudes in the framework of NRQCD factorization, which we dub \\mtt{HELAC-Onia}. We rewrote the original \\mtt{HELAC} to make the new program be able to calculate helicity amplitudes of multi P-wave quarkonium states production at hadron colliders and electron-positron colliders by including new P-wave off-shell currents. Therefore, besides the high efficiencies in computation of multi-leg processes within the Standard Model, \\mtt{HELAC-Onia} is also sufficiently numerical stable in dealing with P-wave quarkonia (e.g. $h_{c,b},\\chi_{c,b}$) and P-wave color-octet intermediate states. To the best of our knowledge, it is a first general-purpose automatic quarkonium matrix elements generator based on recursion relations on the market.
Grassmann integral and Balian–Brézin decomposition in Hartree–Fock–Bogoliubov matrix elements
Energy Technology Data Exchange (ETDEWEB)
Mizusaki, Takahiro, E-mail: mizusaki@isc.senshu-u.ac.jp [Institute of Natural Sciences, Senshu University, 3-8-1 Kanda-Jinbocho, Chiyoda-ku, Tokyo 101-8425 (Japan); Oi, Makito [Institute of Natural Sciences, Senshu University, 3-8-1 Kanda-Jinbocho, Chiyoda-ku, Tokyo 101-8425 (Japan); Chen, Fang-Qi [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sun, Yang [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)
2013-08-09
We present a new formula to calculate matrix elements of a general unitary operator with respect to Hartree–Fock–Bogoliubov states allowing multiple quasi-particle excitations. The Balian–Brézin decomposition of the unitary operator [R. Balian, E. Brézin, Il Nuovo Cimento B 64 (1969) 37] is employed in the derivation. We found that this decomposition is extremely suitable for an application of Fermion coherent state and Grassmann integrals in the quasi-particle basis. The resultant formula is compactly expressed in terms of the Pfaffian, and shows the similar bipartite structure to the formula that we have previously derived in the bare-particles basis [T. Mizusaki, M. Oi, Phys. Lett. B 715 (2012) 219].
Extraction of the CKM matrix element Vus from the hyperon semileptonic decays
International Nuclear Information System (INIS)
Sharma, N.; Dahiya, H.; Chatley, P.K.
2010-01-01
The chiral constituent quark model with configuration mixing (χCQM config ), which is successful in explaining the weak vector and axial-vector form factors for the strangeness-changing as well as strangeness-nonchanging hyperon semileptonic decays at Q 2 =0, has been extended to determine the CKM matrix element V us for the strangeness-changing decays. The implications of the effect of the SU(3) symmetry breaking, Q 2 -dependence and radiative corrections on the form factors and V us have also been investigated. It is found that the results with SU(3) symmetry breaking show considerable improvement over the SU(3) symmetric results when compared with the existing experimental data. The inclusion of the Q 2 -dependence and radiative corrections in form factors have only a small effect on the prediction of V us as is expected from the theory. (orig.)
Massive 3-loop ladder diagrams for quarkonic local operator matrix elements
International Nuclear Information System (INIS)
Ablinger, Jakob; Blümlein, Johannes; Hasselhuhn, Alexander; Klein, Sebastian; Schneider, Carsten; Wißbrock, Fabian
2012-01-01
3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with ξ∈{1,1/2,2} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q 2 ≫m 2 .
Minimizing matrix effect by femtosecond laser ablation and ionization in elemental determination.
Zhang, Bochao; He, Miaohong; Hang, Wei; Huang, Benli
2013-05-07
Matrix effect is unavoidable in direct solid analysis, which usually is a leading cause of the nonstoichiometric effect in quantitative analysis. In this research, experiments were carried out to study the overall characteristics of atomization and ionization in laser-solid interaction. Both nanosecond (ns) and femtosecond (fs) lasers were applied in a buffer-gas-assisted ionization source coupled with an orthogonal time-of-flight mass spectrometer. Twenty-nine solid standards of ten different matrices, including six metals and four dielectrics, were analyzed. The results indicate that the fs-laser mode offers more stable relative sensitivity coefficients (RSCs) with irradiance higher than 7 × 10(13) W·cm(-2), which could be more reliable in the determination of element composition of solids. The matrix effect is reduced by half when the fs-laser is employed, owing to the fact that the fs-laser ablation and ionization (fs-LAI) incurs an almost heat-free ablation process and creates a dense plasma for the stable ionization.
Single-particle characterization of the High Arctic summertime aerosol
Sierau, B.; Chang, R. Y.-W.; Leck, C.; Paatero, J.; Lohmann, U.
2014-01-01
Single-particle mass spectrometric measurements were carried out in the High Arctic north of 80° during summer 2008. The campaign took place onboard the icebreaker Oden and was part of the Arctic Summer Cloud Ocean Study (ASCOS). The instrument deployed was an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) that provides information on the chemical composition of individual particles and their mixing state in real-time. Aerosols were sampled in the marine boundary layer at stations in the open ocean, in the marginal ice zone, and in the pack ice region. The largest fraction of particles detected for subsequent analysis in the size range of the ATOFMS between approximately 200 nm to 3000 nm in diameter showed mass spectrometric patterns indicating an internal mixing state and a biomass burning and/or biofuel source. The majority of these particles were connected to an air mass layer of elevated particle concentration mixed into the surface mixed layer from the upper part of the marine boundary layer. The second largest fraction was represented by sea salt particles. The chemical analysis of the over-ice sea salt aerosol revealed tracer compounds that reflect chemical aging of the particles during their long-range advection from the marginal ice zone, or open waters south thereof prior to detection at the ship. From our findings we conclude that long-range transport of particles is one source of aerosols in the High Arctic. To assess the importance of long-range particle sources for aerosol-cloud interactions over the inner Arctic in comparison to local and regional biogenic primary aerosol sources, the chemical composition of the detected particles was analyzed for indicators of marine biological origin. Only a~minor fraction showed chemical signatures of potentially ocean-derived primary particles of that kind. However, a chemical bias in the ATOFMS's detection capabilities observed during ASCOS might suggest a presence of a particle type of unknown composition
Directory of Open Access Journals (Sweden)
Sergiu Ciprian Catinas
2015-07-01
Full Text Available A detailed theoretical and practical investigation of the reinforced concrete elements is due to recent techniques and method that are implemented in the construction market. More over a theoretical study is a demand for a better and faster approach nowadays due to rapid development of the calculus technique. The paper above will present a study for implementing in a static calculus the direct stiffness matrix method in order capable to address phenomena related to different stages of loading, rapid change of cross section area and physical properties. The method is a demand due to the fact that in our days the FEM (Finite Element Method is the only alternative to such a calculus and FEM are considered as expensive methods from the time and calculus resources point of view. The main goal in such a method is to create the moment-curvature diagram in the cross section that is analyzed. The paper above will express some of the most important techniques and new ideas as well in order to create the moment curvature graphic in the cross sections considered.
Jiao, C. F.; Engel, J.; Holt, J. D.
2017-11-01
We use the generator-coordinate method (GCM) with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless double-β decay of 48Ca, 76Ge, and 82Se. We work in one major shell for the first isotope, in the f5 /2p g9 /2 space for the second and third, and finally in two major shells for all three. Our coordinates include not only the usual axial deformation parameter β , but also the triaxiality angle γ and neutron-proton pairing amplitudes. In the smaller model spaces our matrix elements agree well with those of full shell-model diagonalization, suggesting that our Hamiltonian-based GCM captures most of the important valence-space correlations. In two major shells, where exact diagonalization is not currently possible, our matrix elements are only slightly different from those in a single shell.
Energy Technology Data Exchange (ETDEWEB)
Martini, Till; Uwer, Peter [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstraße 15, 12489 Berlin (Germany)
2015-09-14
In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e{sup +}e{sup −} annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.
International Nuclear Information System (INIS)
Martini, Till; Uwer, Peter
2015-01-01
In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e"+e"− annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.
Abegglen, Manuel; Brem, B. T.; Ellenrieder, M.; Durdina, L.; Rindlisbacher, T.; Wang, J.; Lohmann, U.; Sierau, B.
2016-06-01
Non-volatile aircraft engine emissions are an important anthropogenic source of soot particles in the upper troposphere and in the vicinity of airports. They influence climate and contribute to global warming. In addition, they impact air quality and thus human health and the environment. The chemical composition of non-volatile particulate matter emission from aircraft engines was investigated using single particle time-of-flight mass spectrometry. The exhaust from three different aircraft engines was sampled and analyzed. The soot particulate matter was sampled directly behind the turbine in a test cell at Zurich Airport. Single particle analyses will focus on metallic compounds. The particles analyzed herein represent a subset of the emissions composed of the largest particles with a mobility diameter >100 nm due to instrumental restrictions. A vast majority of the analyzed particles was shown to contain elemental carbon, and depending on the engine and the applied thrust the elemental carbon to total carbon ratio ranged from 83% to 99%. The detected metallic compounds were all internally mixed with the soot particles. The most abundant metals in the exhaust were Cr, Fe, Mo, Na, Ca and Al; V, Ba, Co, Cu, Ni, Pb, Mg, Mn, Si, Ti and Zr were also detected. We further investigated potential sources of the ATOFMS-detected metallic compounds using Inductively Coupled Plasma Mass Spectrometry. The potential sources considered were kerosene, engine lubrication oil and abrasion from engine wearing components. An unambiguous source apportionment was not possible because most metallic compounds were detected in several of the analyzed sources.
Multi-color single particle tracking with quantum dots.
Directory of Open Access Journals (Sweden)
Eva C Arnspang
Full Text Available Quantum dots (QDs have long promised to revolutionize fluorescence detection to include even applications requiring simultaneous multi-species detection at single molecule sensitivity. Despite the early promise, the unique optical properties of QDs have not yet been fully exploited in e. g. multiplex single molecule sensitivity applications such as single particle tracking (SPT. In order to fully optimize single molecule multiplex application with QDs, we have in this work performed a comprehensive quantitative investigation of the fluorescence intensities, fluorescence intensity fluctuations, and hydrodynamic radii of eight types of commercially available water soluble QDs. In this study, we show that the fluorescence intensity of CdSe core QDs increases as the emission of the QDs shifts towards the red but that hybrid CdSe/CdTe core QDs are less bright than the furthest red-shifted CdSe QDs. We further show that there is only a small size advantage in using blue-shifted QDs in biological applications because of the additional size of the water-stabilizing surface coat. Extending previous work, we finally also show that parallel four color multicolor (MC-SPT with QDs is possible at an image acquisition rate of at least 25 Hz. We demonstrate the technique by measuring the lateral dynamics of a lipid, biotin-cap-DPPE, in the cellular plasma membrane of live cells using four different colors of QDs; QD565, QD605, QD655, and QD705 as labels.
Hierarchical Ag mesostructures for single particle SERS substrate
Energy Technology Data Exchange (ETDEWEB)
Xu, Minwei, E-mail: xuminwei@xjtu.edu.cn; Zhang, Yin
2017-01-30
Highlights: • Hierarchical Ag mesostructures with the size of 250, 360 and 500 nm are synthesized via a seed-mediated approach. • The Ag mesostructures present the tailorable size and highly roughened surfaces. • The average enhancement factors for individual Ag mesostructures were estimated to be as high as 10{sup 6}. - Abstract: Hierarchical Ag mesostructures with highly rough surface morphology have been synthesized at room temperature through a simple seed-mediated approach. Electron microscopy characterizations indicate that the obtained Ag mesostructures exhibit a textured surface morphology with the flower-like architecture. Moreover, the particle size can be tailored easily in the range of 250–500 nm. For the growth process of the hierarchical Ag mesostructures, it is believed that the self-assembly mechanism is more reasonable rather than the epitaxial overgrowth of Ag seed. The oriented attachment of nanoparticles is revealed during the formation of Ag mesostructures. Single particle surface enhanced Raman spectra (sp-SERS) of crystal violet adsorbed on the hierarchical Ag mesostructures were measured. Results reveal that the hierarchical Ag mesostructures can be highly sensitive sp-SERS substrates with good reproducibility. The average enhancement factors for individual Ag mesostructures are estimated to be about 10{sup 6}.
Single particle composition measurements of artificial Calcium Carbonate aerosols
Zorn, S. R.; Mentel, T. F.; Schwinger, T.; Croteau, P. L.; Jayne, J.; Worsnop, D. R.; Trimborn, A.
2012-12-01
Mineral dust, with an estimated total source from natural and anthropogenic emissions of up to 2800 Tg/yr, is one of the two largest contributors to total aerosol mass, with only Sea salt having a similar source strength (up to 2600 Tg/yr). The composition of dust particles varies strongly depending on the production process and, most importantly, the source location. Therefore, the composition of single dust particles can be used both to trace source regions of air masses as well as to identify chemical aging processes. Here we present results of laboratory studies on generating artificial calcium carbonate (CaCO3) particles, a model compound for carbonaceous mineral dust particles. Particles were generated by atomizing an aqueous hydrogen carbonate solution. Water was removed using a silica diffusion dryer., then the particles were processed in an oven at temperatures up to 900°C, converting the hydrogen carbonate to its anhydrous form. The resulting aerosol was analyzed using an on-line single particle laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF). The results confirm the conversion to calcium carbonate, and validate that the produced particles indeed can be used as a model compound for carbonaceous dust aerosols.
Simulating Biomass Fast Pyrolysis at the Single Particle Scale
Energy Technology Data Exchange (ETDEWEB)
Ciesielski, Peter [National Renewable Energy Laboratory (NREL); Wiggins, Gavin [ORNL; Daw, C Stuart [ORNL; Jakes, Joseph E. [U.S. Forest Service, Forest Products Laboratory, Madison, Wisconsin, USA
2017-07-01
Simulating fast pyrolysis at the scale of single particles allows for the investigation of the impacts of feedstock-specific parameters such as particle size, shape, and species of origin. For this reason particle-scale modeling has emerged as an important tool for understanding how variations in feedstock properties affect the outcomes of pyrolysis processes. The origins of feedstock properties are largely dictated by the composition and hierarchical structure of biomass, from the microstructural porosity to the external morphology of milled particles. These properties may be accounted for in simulations of fast pyrolysis by several different computational approaches depending on the level of structural and chemical complexity included in the model. The predictive utility of particle-scale simulations of fast pyrolysis can still be enhanced substantially by advancements in several areas. Most notably, considerable progress would be facilitated by the development of pyrolysis kinetic schemes that are decoupled from transport phenomena, predict product evolution from whole-biomass with increased chemical speciation, and are still tractable with present-day computational resources.
International Nuclear Information System (INIS)
Filippov, G.F.; Ovcharenko, V.I.; Teryoshin, Yu.V.
1980-01-01
For near-magnetic nuclei, the matrix elements of the central exchange nucleon-nucleon interaction potential energy operator between the generating functions of the total basis of the Sn are obtained. The basis states are highest weigt vectorsp(2,R) irreducible representatio of the SO(3) irredicible representation and in addition, have a definite O(A-1) symmetry. The Sp(2,R) basis generating matrix elements simplify essentially the problem of calculating the spectrum of collective excitations of the atomic nucleus over an intrinsic function of definite O(A-1) symmetry
Deblurring of class-averaged images in single-particle electron microscopy
International Nuclear Information System (INIS)
Park, Wooram; Chirikjian, Gregory S; Madden, Dean R; Rockmore, Daniel N
2010-01-01
This paper proposes a method for the deblurring of class-averaged images in single-particle electron microscopy (EM). Since EM images of biological samples are very noisy, the images which are nominally identical projection images are often grouped, aligned and averaged in order to cancel or reduce the background noise. However, the noise in the individual EM images generates errors in the alignment process, which creates an inherent limit on the accuracy of the resulting class averages. This inaccurate class average due to the alignment errors can be viewed as the result of a convolution of an underlying clear image with a blurring function. In this work, we develop a deconvolution method that gives an estimate for the underlying clear image from a blurred class-averaged image using precomputed statistics of misalignment. Since this convolution is over the group of rigid-body motions of the plane, SE(2), we use the Fourier transform for SE(2) in order to convert the convolution into a matrix multiplication in the corresponding Fourier space. For practical implementation we use a Hermite-function-based image modeling technique, because Hermite expansions enable lossless Cartesian-polar coordinate conversion using the Laguerre–Fourier expansions, and Hermite expansion and Laguerre–Fourier expansion retain their structures under the Fourier transform. Based on these mathematical properties, we can obtain the deconvolution of the blurred class average using simple matrix multiplication. Tests of the proposed deconvolution method using synthetic and experimental EM images confirm the performance of our method
Single-particle motion in large-amplitude quadrupole shape transition
International Nuclear Information System (INIS)
Yamada, Kazuya
1991-01-01
The microscopic structure of the single-particle motion for the spherical-deformed transitional nuclei is analysed by using the self-consistent collective-coordinate method (SCC method). The single-particle motion in the moving-frame of reference called the collective vibrating coordinate frame is introduced by the generalized Bogoliubov transformation depending on the collective coordinate. The numerical calculations of the single-particle (quasi-particle) energy level diagrams and their occupation probabilities for the static deformation are carried out for the Sm isotopes. A clear change of the single-particle distribution structure appears in the course of deformation. (author)
International Nuclear Information System (INIS)
Ott, R.T.; Sansoz, F.; Molinari, J.F.; Almer, J.; Ramesh, K.T.; Hufunagel, T.C.
2005-01-01
In situ X-ray scattering and finite element modeling (FEM) were used to examine the micromechanics of deformation of in situ formed metallic-glass-matrix composites consisting of Ta-rich particles dispersed in an amorphous matrix. The strain measurements show that under uniaxial compression the second-phase particles yield at an applied stress of approx. 325 MPa. After yielding, the particles do not strain harden significantly; we show that this is due to an increasingly hydrostatic stress state arising from the lateral constraint on deformation of the particles imposed by the elastic matrix. Shear band initiation in the matrix is not due to the difference in elastic properties between the matrix and the particles. Rather, the development of a plastic misfit strain causes stress concentrations around the particles, resulting in localized yielding of the matrix by shear band formation at an applied stress of approx. 1450 MPa, considerably lower than the macroscopic yield stress of the composite (approx. 1725 MPa). Shear bands do not propagate at the lower stress because the yield criterion of the matrix is only satisfied in the region immediately around the particles. At the higher stresses, the yield criterion is satisfied in large regions of the matrix, allowing extensive shear band propagation and significant macroscopic plastic deformation. However, the presence of the particles makes the stress state highly inhomogeneous, which may partially explain why fracture is suppressed in the composite, allowing the development of large plastic strains
Laboratory Measurements of Single-Particle Polarimetric Spectrum
Gritsevich, M.; Penttila, A.; Maconi, G.; Kassamakov, I.; Helander, P.; Puranen, T.; Salmi, A.; Hæggström, E.; Muinonen, K.
2017-12-01
Measuring scattering properties of different targets is important for material characterization, remote sensing applications, and for verifying theoretical results. Furthermore, there are usually simplifications made when we model targets and compute the scattering properties, e.g., ideal shape or constant optical parameters throughout the target material. Experimental studies help in understanding the link between the observed properties and computed results. Experimentally derived Mueller matrices of studied particles can be used as input for larger-scale scattering simulations, e.g., radiative transfer computations. This method allows to bypass the problem of using an idealized model for single-particle optical properties. While existing approaches offer ensemble- and orientation-averaged particle properties, our aim is to measure individual particles with controlled or known orientation. With the newly developed scatterometer, we aim to offer novel possibility to measure single, small (down to μm-scale) targets and their polarimetric spectra. This work presents an experimental setup that measures light scattered by a fixed small particle with dimensions ranging between micrometer and millimeter sizes. The goal of our setup is nondestructive characterization of such particles by measuring light of multiple wavelengths scattered in 360° in a horizontal plane by an ultrasonically levitating sample, whilst simultaneously controlling its 3D position and orientation. We describe the principles and design of our instrument and its calibration. We also present example measurements of real samples. This study was conducted under the support from the European Research Council, in the frame of the Advanced Grant project No. 320773 `Scattering and Absorption of Electromagnetic Waves in Particulate Media' (SAEMPL).
Dynamic-stiffness matrix of embedded and pile foundations by indirect boundary-element method
International Nuclear Information System (INIS)
Wolf, J.P.; Darbre, G.R.
1984-01-01
The boundary-integral equation method is well suited for the calculation of the dynamic-stiffness matrix of foundations embedded in a layered visco-elastic halfspace (or a transmitting boundary of arbitrary shape), which represents an unbounded domain. It also allows pile groups to be analyzed, taking pile-soil-pile interaction into account. The discretization of this boundary-element method is restricted to the structure-soil interface. All trial functions satisfy exactly the field equations and the radiation condition at infinity. In the indirect boundary-element method distributed source loads of initially unknown intensities act on a source line located in the excavated part of the soil and are determined such that the prescribed boundary conditions on the structure-soil interface are satisfied in an average sense. In the two-dimensional case the variables are expanded in a Fourier integral in the wave number domain, while in three dimensions, Fourier series in the circumferential direction and bessel functions of the wave number domain, while in three dimensions, Fourier series in the circumferential direction and Bessel functions of the wave number in the radial direction are selected. Accurate results arise with a small number of parameters of the loads acting on a source line which should coincide with the structure-soil interface. In a parametric study the dynamic-stiffness matrices of rectangular foundations of various aspect ratios embedded in a halfplane and in a layer built-in at its base are calculated. For the halfplane, the spring coefficients for the translational directions hardly depend on the embedment, while the corresponding damping coefficients increase for larger embedments, this tendency being more pronounced in the horizontal direction. (orig.)
International Nuclear Information System (INIS)
Badalov, S.A.; Filippov, G.F.
1986-01-01
The receipts to calculate the generating matrix elements of the algebraic version of resonating group method (RGM) are given for two- and three-cluster nucleon systems, the center of mass motion being separeted exactly. For the Hamiltonian with Gaussian nucleon-nucleon potential dependence the generating matrix elements of the RGM algebraic version can be written down explictly if matrix elements of the corresponding system on wave functions of the Brink cluster model are known
Bubin, Sergiy; Adamowicz, Ludwik
2008-03-01
In this work we consider explicitly correlated complex Gaussian basis functions for expanding the wave function of an N-particle system with the L =1 total orbital angular momentum. We derive analytical expressions for various matrix elements with these basis functions including the overlap, kinetic energy, and potential energy (Coulomb interaction) matrix elements, as well as matrix elements of other quantities. The derivatives of the overlap, kinetic, and potential energy integrals with respect to the Gaussian exponential parameters are also derived and used to calculate the energy gradient. All the derivations are performed using the formalism of the matrix differential calculus that facilitates a way of expressing the integrals in an elegant matrix form, which is convenient for the theoretical analysis and the computer implementation. The new method is tested in calculations of two systems: the lowest P state of the beryllium atom and the bound P state of the positronium molecule (with the negative parity). Both calculations yielded new, lowest-to-date, variational upper bounds, while the number of basis functions used was significantly smaller than in previous studies. It was possible to accomplish this due to the use of the analytic energy gradient in the minimization of the variational energy.
Bubin, Sergiy; Adamowicz, Ludwik
2008-03-21
In this work we consider explicitly correlated complex Gaussian basis functions for expanding the wave function of an N-particle system with the L=1 total orbital angular momentum. We derive analytical expressions for various matrix elements with these basis functions including the overlap, kinetic energy, and potential energy (Coulomb interaction) matrix elements, as well as matrix elements of other quantities. The derivatives of the overlap, kinetic, and potential energy integrals with respect to the Gaussian exponential parameters are also derived and used to calculate the energy gradient. All the derivations are performed using the formalism of the matrix differential calculus that facilitates a way of expressing the integrals in an elegant matrix form, which is convenient for the theoretical analysis and the computer implementation. The new method is tested in calculations of two systems: the lowest P state of the beryllium atom and the bound P state of the positronium molecule (with the negative parity). Both calculations yielded new, lowest-to-date, variational upper bounds, while the number of basis functions used was significantly smaller than in previous studies. It was possible to accomplish this due to the use of the analytic energy gradient in the minimization of the variational energy.
K →π matrix elements of the chromomagnetic operator on the lattice
Constantinou, M.; Costa, M.; Frezzotti, R.; Lubicz, V.; Martinelli, G.; Meloni, D.; Panagopoulos, H.; Simula, S.; ETM Collaboration
2018-04-01
We present the results of the first lattice QCD calculation of the K →π matrix elements of the chromomagnetic operator OCM=g s ¯ σμ νGμ νd , which appears in the effective Hamiltonian describing Δ S =1 transitions in and beyond the standard model. Having dimension five, the chromomagnetic operator is characterized by a rich pattern of mixing with operators of equal and lower dimensionality. The multiplicative renormalization factor as well as the mixing coefficients with the operators of equal dimension have been computed at one loop in perturbation theory. The power divergent coefficients controlling the mixing with operators of lower dimension have been determined nonperturbatively, by imposing suitable subtraction conditions. The numerical simulations have been carried out using the gauge field configurations produced by the European Twisted Mass Collaboration with Nf=2 +1 +1 dynamical quarks at three values of the lattice spacing. Our result for the B parameter of the chromomagnetic operator at the physical pion and kaon point is BCMOK π=0.273 (69 ) , while in the SU(3) chiral limit we obtain BCMO=0.076 (23 ) . Our findings are significantly smaller than the model-dependent estimate BCMO˜1 - 4 , currently used in phenomenological analyses, and improve the uncertainty on this important phenomenological quantity.
Phenomenological renormalization of free nucleon-nucleon interaction. [Sussex matrix elements
Energy Technology Data Exchange (ETDEWEB)
Prakash, M; Waghmare, Y R [Indian Inst. of Tech., Kanpur. Dept. of Physics; Mehrotra, I [Allahabad Univ. (India). Dept. of Physics
1976-08-01
Low-lying spectra of /sup 6/Li, /sup 18/F, /sup 18/O, /sup 42/Sc, /sup 42/Ca, /sup 58/Ni and /sup 92/Zr are studied with Sussex matrix elements (SME) and their central, spin-orbit and tensor components. It is observed that major contribution to level energies comes from the central part, while the tensor part provides the finer details of spectra, particularly for T = 0 levels. The spin-orbit part does not make any appreciable contribution to level energies. A phenomenological renormalization fo the SME is carried out to improve the agreement with the experimental results. It turns out that some of the low-lying T = 0 levels can be satisfactorily described if the SME in the /sup 3/S/sub 1/ relative state are made (1+..cap alpha..) times their bare interaction value, where ..cap alpha.. is a constant to be determined from a comparison with experimental level energies. Similarly, for T = 1 levels, better agreement with the experimental results is obtained if a delta-function-plus-quadrupole interaction is added to the SME.
International Nuclear Information System (INIS)
Fatchurrohman, N; Marini, C D; Suraya, S; Iqbal, AKM Asif
2016-01-01
The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc. (paper)
Quarkonium polarization and the long distance matrix elements hierarchies using jet substructure
Dai, Lin; Shrivastava, Prashant
2017-08-01
We investigate the quarkonium production mechanisms in jets at the LHC, using the fragmenting jet functions (FJF) approach. Specifically, we discuss the jet energy dependence of the J /ψ production cross section at the LHC. By comparing the cross sections for the different NRQCD production channels (1S0[8], 3S1[8], 3PJ[8], and 3cripts>S1[1]), we find that at fixed values of energy fraction z carried by the J /ψ , if the normalized cross section is a decreasing function of the jet energy, in particular for z >0.5 , then the depolarizing 1S0[8] must be the dominant channel. This makes the prediction made in [Baumgart et al., J. High Energy Phys. 11 (2014) 003, 10.1007/JHEP11(2014)003] for the FJF's also true for the cross section. We also make comparisons between the long distance matrix elements extracted by various groups. This analysis could potentially shed light on the polarization properties of the J /ψ production in high pT region.
Angeli, C.; Cimiraglia, R.
2013-02-01
A symbolic program performing the Formal Reduction of Density Operators (FRODO), formerly developed in the MuPAD computer algebra system with the purpose of evaluating the matrix elements of the electronic Hamiltonian between internally contracted functions in a complete active space (CAS) scheme, has been rewritten in Mathematica. New version : A program summaryProgram title: FRODO Catalogue identifier: ADV Y _v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVY_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3878 No. of bytes in distributed program, including test data, etc.: 170729 Distribution format: tar.gz Programming language: Mathematica Computer: Any computer on which the Mathematica computer algebra system can be installed Operating system: Linux Classification: 5 Catalogue identifier of previous version: ADV Y _v1_0 Journal reference of previous version: Comput. Phys. Comm. 171(2005)63 Does the new version supersede the previous version?: No Nature of problem. In order to improve on the CAS-SCF wavefunction one can resort to multireference perturbation theory or configuration interaction based on internally contracted functions (ICFs) which are obtained by application of the excitation operators to the reference CAS-SCF wavefunction. The previous formulation of such matrix elements in the MuPAD computer algebra system, has been rewritten using Mathematica. Solution method: The method adopted consists in successively eliminating all occurrences of inactive orbital indices (core and virtual) from the products of excitation operators which appear in the definition of the ICFs and in the electronic Hamiltonian expressed in the second quantization formalism. Reasons for new version: Some years ago we published in this journal a couple of papers [1, 2
International Nuclear Information System (INIS)
Ablinger, J.; Schneider, C.; Manteuffel, A. von
2015-09-01
Three loop ladder and V-topology diagrams contributing to the massive operator matrix element A Qg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.
A measurement of the top quark mass with a matrix element method
Energy Technology Data Exchange (ETDEWEB)
Gibson, Adam Paul [Univ. of California, Berkeley, CA (United States)
2006-01-01
The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb^{-1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t$\\bar{t}$ and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb^{-1} dataset they extract a top quark mass of 172.0 ± 2.6(stat) ± 3.3(syst) GeV/c^{2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c^{2} for m $\\bar{t}$ = 178 GTeV/c^{2} and 3.1 GeV/c^{2} for m $\\bar{t}$ = 172.5 GeV/c^{2}. The systematic error is dominated by the uncertainty of the jet energy scale.
Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; von Manteuffel, A.; Schneider, C.
2016-05-01
Three loop ladder and V-topology diagrams contributing to the massive operator matrix element AQg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.
Study on thermal conductivity of HTR spherical fuel element matrix graphite
International Nuclear Information System (INIS)
Zhang Kaihong; Liu Xiaoxue; Zhao Hongsheng; Li Ziqiang; Tang Chunhe
2014-01-01
Taking the spherical fuel element matrix graphite ball samples as an example, this paper introduced the principle and method of laser thermal conductivity meter, as well as the specific heat capacity, and analyzed the effects of different test methods and sampling methods on the thermal conductivities at 1000 ℃ of graphite material. The experimental results show that the thermal conductivities of graphite materials tested by synchronous thermal analyzer combining with laser thermal conductivity meter were different from that directly by laser thermal conductivity meter, the former was more reliable and accurate than the later; When sampling from different positions, central samples had higher thermal conductivities than edging samples, which was related to the material density and porosity at the different locations; the thermal conductivities had obvious distinction between samples from different directions, which was because the layer structure of polycrystalline graphite preferred orientation under pressure, generally speaking, the thermal conductivities perpendicular to the molding direction were higher than that parallel to the molding direction. Besides this, the test results show that the thermal conductivities of all the graphite material samples were greater than 30 W/(m (K), achieving the thermal performance index of high temperature gas cooled reactor. (authors)
Calculations with off-shell matrix elements, TMD parton densities and TMD parton showers
Energy Technology Data Exchange (ETDEWEB)
Bury, Marcin; Hameren, Andreas van; Kutak, Krzysztof; Sapeta, Sebastian [Polish Academy of Sciences, Institute of Nuclear Physics, Cracow (Poland); Jung, Hannes [Polish Academy of Sciences, Institute of Nuclear Physics, Cracow (Poland); DESY, Hamburg (Germany); Serino, Mirko [Polish Academy of Sciences, Institute of Nuclear Physics, Cracow (Poland); Ben Gurion University of the Negev, Department of Physics, Beersheba (Israel)
2018-02-15
A new calculation using off-shell matrix elements with TMD parton densities supplemented with a newly developed initial state TMD parton shower is described. The calculation is based on the KaTie package for an automated calculation of the partonic process in high-energy factorization, making use of TMD parton densities implemented in TMDlib. The partonic events are stored in an LHE file, similar to the conventional LHE files, but now containing the transverse momenta of the initial partons. The LHE files are read in by the Cascade package for the full TMD parton shower, final state shower and hadronization from Pythia where events in HEPMC format are produced. We have determined a full set of TMD parton densities and developed an initial state TMD parton shower, including all flavors following the TMD distribution. As an example of application we have calculated the azimuthal de-correlation of high p{sub t} dijets as measured at the LHC and found very good agreement with the measurement when including initial state TMD parton showers together with conventional final state parton showers and hadronization. (orig.)
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
Energy Technology Data Exchange (ETDEWEB)
Ablinger, Jakob [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Blümlein, Johannes; Raab, Clemens [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Schneider, Carsten [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Wißbrock, Fabian [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2014-08-15
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version of the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators, new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∼30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N∈C. Integrals with a power-like divergence in N-space ∝a{sup N},a∈R,a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions.
Calculating massive 3-loop graphs for operator matrix elements by the method of hyperlogarithms
International Nuclear Information System (INIS)
Ablinger, Jakob; Blümlein, Johannes; Raab, Clemens; Schneider, Carsten; Wißbrock, Fabian
2014-01-01
We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist τ=2 local operator insertions corresponding to spin N. They contribute to the massive operator matrix elements in QCD describing the massive Wilson coefficients for deep-inelastic scattering at large virtualities. Diagrams of this kind can be computed using an extended version of the method of hyperlogarithms, originally being designed for massless Feynman diagrams without operators. The method is applied to Benz- and V-type graphs, belonging to the genuine 3-loop topologies. In case of the V-type graphs with five massive propagators, new types of nested sums and iterated integrals emerge. The sums are given in terms of finite binomially and inverse binomially weighted generalized cyclotomic sums, while the 1-dimensionally iterated integrals are based on a set of ∼30 square-root valued letters. We also derive the asymptotic representations of the nested sums and present the solution for N∈C. Integrals with a power-like divergence in N-space ∝a N ,a∈R,a>1, for large values of N emerge. They still possess a representation in x-space, which is given in terms of root-valued iterated integrals in the present case. The method of hyperlogarithms is also used to calculate higher moments for crossed box graphs with different operator insertions
Matrix elements of four-quark operators relevant to life time difference ΔΓBs from QCD sum rules
International Nuclear Information System (INIS)
Huang, C.S.; Zhang Ailin; Zhu, S.L.
2001-01-01
We extract the matrix elements of four-quark operators O L,S relevant to the B s and anti B s life time difference from QCD sum rules. We find that the vacuum saturation approximation works reasonably well, i.e., within 10%. We discuss the implications of our results and compare them with a recent lattice QCD determination. (orig.)
Study of color-octet matrix elements through J/ψ production in e{sup +}e{sup -} annihilation
Energy Technology Data Exchange (ETDEWEB)
Li, Yi-Jie; Xu, Guang-Zhi; Zhang, Pan-Pan; Liu, Kui-Yong [Liaoning University, Department of Physics, Shenyang (China); Zhang, Yu-Jie [Beihang University, School of Physics, Beijing (China); CAS Center for Excellence in Particle Physics, Beijing (China)
2017-09-15
In this paper, the color-octet long distance matrix elements are studied through the inclusive J/ψ production in e{sup +}e{sup -} annihilation within the framework of non-relativistic QCD factorization. The calculations are up-to next-to-leading order with the radiative and relativistic corrections in the energy region of the B-factory and the near-threshold region of 4.6-5.6 GeV. A constraint of the long distance matrix elements (left angle {sup 1}S{sub 0}{sup 8} right angle, left angle {sup 3}P{sub 0}{sup 8} right angle) is obtained. Through our estimation, the P-wave color-octet matrix element (left angle 0 vertical stroke {sup 3}P{sup 8}{sub 0} vertical stroke 0 right angle) should be of the order of 0.008m{sub c}{sup 2} GeV{sup 3} or less. The constrained region is not compatible with the values of the long distance matrix elements fitted at hadron colliders. (orig.)
International Nuclear Information System (INIS)
Zhang, L.
1981-08-01
A method based on the tight-binding approximation is developed to calculate the electron-phonon matrix element for the disordered transition metals. With the method as a basis the experimental Tsub(c) data of the amorphous transition metal superconductors are re-analysed. Some comments on the superconductivity of the disordered materials are given
Gradient-based stochastic estimation of the density matrix
Wang, Zhentao; Chern, Gia-Wei; Batista, Cristian D.; Barros, Kipton
2018-03-01
Fast estimation of the single-particle density matrix is key to many applications in quantum chemistry and condensed matter physics. The best numerical methods leverage the fact that the density matrix elements f(H)ij decay rapidly with distance rij between orbitals. This decay is usually exponential. However, for the special case of metals at zero temperature, algebraic decay of the density matrix appears and poses a significant numerical challenge. We introduce a gradient-based probing method to estimate all local density matrix elements at a computational cost that scales linearly with system size. For zero-temperature metals, the stochastic error scales like S-(d+2)/2d, where d is the dimension and S is a prefactor to the computational cost. The convergence becomes exponential if the system is at finite temperature or is insulating.
Energy Technology Data Exchange (ETDEWEB)
Birkholzer, J.; Karasaki, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.
1996-07-01
Fracture network simulators have extensively been used in the past for obtaining a better understanding of flow and transport processes in fractured rock. However, most of these models do not account for fluid or solute exchange between the fractures and the porous matrix, although diffusion into the matrix pores can have a major impact on the spreading of contaminants. In the present paper a new finite element code TRIPOLY is introduced which combines a powerful fracture network simulator with an efficient method to account for the diffusive interaction between the fractures and the adjacent matrix blocks. The fracture network simulator used in TRIPOLY features a mixed Lagrangian-Eulerian solution scheme for the transport in fractures, combined with an adaptive gridding technique to account for sharp concentration fronts. The fracture-matrix interaction is calculated with an efficient method which has been successfully used in the past for dual-porosity models. Discrete fractures and matrix blocks are treated as two different systems, and the interaction is modeled by introducing sink/source terms in both systems. It is assumed that diffusive transport in the matrix can be approximated as a one-dimensional process, perpendicular to the adjacent fracture surfaces. A direct solution scheme is employed to solve the coupled fracture and matrix equations. The newly developed combination of the fracture network simulator and the fracture-matrix interaction module allows for detailed studies of spreading processes in fractured porous rock. The authors present a sample application which demonstrate the codes ability of handling large-scale fracture-matrix systems comprising individual fractures and matrix blocks of arbitrary size and shape.
International Nuclear Information System (INIS)
Chan, George C.-Y.; Chan, W.-T.
2003-01-01
The effects of Na, K, Ca and Ba matrices on the plasma excitation conditions in inductively coupled plasma-atomic emission spectrometry (ICP-AES) were studied. Normalized relative intensity was used to indicate the extent of the plasma-related matrix effects. The group I matrices have no effects on the plasma excitation conditions. In contrast, the group II matrices depress the normalized relative intensities of some spectral lines. Specifically, the Group II matrices have no effects on the normalized relative intensity of atomic lines of low upper energy level (soft lines), but reduce the normalized relative intensity of some ionic lines and atomic lines of high energy level (hard lines). The Group II matrices seem to shift the Saha balance of the analytes only; no shift in the Boltzmann balance was observed experimentally. Moreover, for some ionic lines with sum of ionization and excitation potentials close to the ionization potential of argon (15.75 eV), the matrix effect is smaller than other ionic lines of the same element. The reduced matrix effects may be attributed qualitatively to charge transfer excitation mechanism of these ionic lines. Charge transfer reaction renders ionic emission lines from the quasi-resonant levels similar in characteristics of atomic lines. The contribution of charge transfer relative to excitation by other non-specific excitation mechanisms (via Saha balance and Boltzmann balance) determines the degree of atomic behavior of a quasi-resonant level. A significant conclusion of this study is that plasma-related matrix effect depends strongly on the excitation mechanism of a spectral line. Since, in general, more than one excitation mechanism may contribute to the overall excitation of an emission line, the observed matrix effects reflect the sum of the effects due to individual excitation mechanisms. Excitation mechanisms, in addition to the often-used total excitation energy, should be considered in matrix effect studies
Report of the working group on single-particle nonlinear dynamics
International Nuclear Information System (INIS)
Bazzani, A.; Bongini, L.; Corbett, J.; Dome, G.; Fedorova, A.; Freguglia, P.; Ng, K.; Ohmi, K.; Owen, H.; Papaphilippou, Y.; Robin, D.; Safranek, J.; Scandale, W.; Terebilo, A.; Turchetti, G.; Todesco, E.; Warnock, R.; Zeitlin, M.
1999-01-01
The Working Group on single-particle nonlinear dynamics has developed a set of tools to study nonlinear dynamics in a particle accelerator. The design of rings with large dynamic apertures is still far from automatic. The Working Group has concluded that nonlinear single-particle dynamics limits the performance of accelerators. (AIP) copyright 1999 American Institute of Physics
The NUMEN project: NUclear Matrix Elements for Neutrinoless double beta decay
Cappuzzello, F.; Agodi, C.; Cavallaro, M.; Carbone, D.; Tudisco, S.; Lo Presti, D.; Oliveira, J. R. B.; Finocchiaro, P.; Colonna, M.; Rifuggiato, D.; Calabretta, L.; Calvo, D.; Pandola, L.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Brunasso, O.; Burrello, S.; Calabrese, S.; Calanna, A.; Chávez Lomelí, E. R.; D'Agostino, G.; De Faria, P. N.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; Ferreira, J. L.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia-Tecocoatzi, H.; Greco, V.; Hacisalihoglu, A.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lay, J. A.; La Via, F.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lubian, J.; Medina, N. H.; Mendes, D. R.; Moralles, M.; Muoio, A.; Pakou, A.; Petrascu, H.; Pinna, F.; Reito, S.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Santos, R. B. B.; Sgouros, O.; da Silveira, M. A. G.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Magana Vsevolodovna, R.; Yildirim, A.; Zagatto, V. A. B.
2018-05-01
The article describes the main achievements of the NUMEN project together with an updated and detailed overview of the related R&D activities and theoretical developments. NUMEN proposes an innovative technique to access the nuclear matrix elements entering the expression of the lifetime of the double beta decay by cross section measurements of heavy-ion induced Double Charge Exchange (DCE) reactions. Despite the fact that the two processes, namely neutrinoless double beta decay and DCE reactions, are triggered by the weak and strong interaction respectively, important analogies are suggested. The basic point is the coincidence of the initial and final state many-body wave functions in the two types of processes and the formal similarity of the transition operators. First experimental results obtained at the INFN-LNS laboratory for the 40Ca(18O,18Ne)40Ar reaction at 270MeV give an encouraging indication on the capability of the proposed technique to access relevant quantitative information. The main experimental tools for this project are the K800 Superconducting Cyclotron and MAGNEX spectrometer. The former is used for the acceleration of the required high resolution and low emittance heavy-ion beams and the latter is the large acceptance magnetic spectrometer for the detection of the ejectiles. The use of the high-order trajectory reconstruction technique, implemented in MAGNEX, allows to reach the experimental resolution and sensitivity required for the accurate measurement of the DCE cross sections at forward angles. However, the tiny values of such cross sections and the resolution requirements demand beam intensities much larger than those manageable with the present facility. The on-going upgrade of the INFN-LNS facilities in this perspective is part of the NUMEN project and will be discussed in the article.
Analysis and differentiation of mineral dust by single particle laser mass spectrometry
International Nuclear Information System (INIS)
Gallavardin, S. J.; Lohmann, U.; Cziczo, Daniel J.
2008-01-01
This study evaluates the potential of single particle laser desorption/ionization mass spectrometry for the analysis of atmospherically relevant mineral dusts. Samples of hematite, goethite, calcium carbonate, calcium sulfate, silica, quartz, montmorrillonite, kaolinite, illite, hectorite, wollastonite and nephelinsyenit were investigated in positive and negative ion mode with a monopolar time-of-flight mass spectrometer where the desorption/ionization step was performed with a 193 nm excimer laser (∼10 9 W/cm 2 ). Particle size ranged from 500 nm to 3 (micro)m. Positive mass spectra mainly provide elemental composition whereas negative ion spectra provide information on element speciation and of a structural nature. The iron oxide, calcium-rich and aluminosilicate nature of particles is established in positive ion mode. The differentiation of calcium materials strongly relies on the calcium counter-ions in negative mass spectra. Aluminosilicates can be differentiated in both positive and negative ion mode using the relative abundance of various aluminum and silicon ions
Swain, J D
1999-01-01
We present a new method for the determination of the Cabibbo- Kobayashi-Maskawa quark mixing matrix element V/sub tb/ from electroweak loop corrections, in particular those affecting the process Z to bb. From a combined analysis of results from the LEP, SLC, Tevatron, and neutrino scattering experiments we determine V /sub tb/=0.77/sub -0.24//sup +18/. We comment briefly on the implications of this measurement for the mass of the top quark and Higgs boson, alpha /sub s/, and CKM unitarity. (19 refs).
Directory of Open Access Journals (Sweden)
Leandro Ferreira Friedrich
Full Text Available Abstract Fiber-matrix interface performance has a great influence on the mechanical properties of fiber reinforced composite. This influence is mainly presented during fiber pullout from the matrix. As fiber pullout process consists of fiber debonding stage and pullout stage which involve complex contact problem, numerical modeling is a best way to investigate the interface influence. Although many numerical research works have been conducted, practical and effective technique suitable for continuous modeling of fiber pullout process is still scarce. The reason is in that numerical divergence frequently happens, leading to the modeling interruption. By interacting the popular finite element program ANSYS with the MATLAB, we proposed continuous modeling technique and realized modeling of fiber pullout from cement matrix with desired interface mechanical performance. For debonding process, we used interface elements with cohesive surface traction and exponential failure behavior. For pullout process, we switched interface elements to spring elements with variable stiffness, which is related to the interface shear stress as a function of the interface slip displacement. For both processes, the results obtained are very good in comparison with other numerical or analytical models and experimental tests. We suggest using the present technique to model toughening achieved by randomly distributed fibers.
International Nuclear Information System (INIS)
Torreno-Pina, Juan A; Manzo, Carlo; Garcia-Parajo, Maria F
2016-01-01
The plasma membrane of eukaryotic cells is responsible for a myriad of functions that regulate cell physiology and plays a crucial role in a multitude of processes that include adhesion, migration, signaling recognition and cell–cell communication. This is accomplished by specific interactions between different membrane components such as lipids and proteins on the lipid bilayer but also through interactions with the underlying cortical actin cytoskeleton on the intracellular side and the glycocalyx matrix in close proximity to the extracellular side. Advanced biophysical techniques, including single particle tracking (SPT) have revealed that the lateral diffusion of molecular components on the plasma membrane represents a landmark manifestation of such interactions. Indeed, by studying changes in the diffusivity of individual membrane molecules, including sub-diffusion, confined diffusion and/or transient arrest of molecules in membrane compartments, it has been possible to gain insight on the nature of molecular interactions and to infer on its functional role for cell response. In this review, we will revise some exciting results where SPT has been crucial to reveal homo- and hetero-interactions on the cell membrane. (paper)
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Universidad Simon Bolivar, Caracas (Venezuela). Dept. de Fisica; Neerven, W. van [Leiden Univ. (Netherlands). Lorentz Institute
2008-12-15
We describe the calculation of the two-loop massive operator matrix elements for massive external fermions. These matrix elements are needed for the calculation of the O({alpha}{sup 2}) initial state radiative corrections to e{sup +}e{sup -} annihilation into a neutral virtual gauge boson, based on the renormalization group technique. (orig.)
Multichannel quantum defect and reduced R-matrix
International Nuclear Information System (INIS)
Hategan, C.; Ionescu, R.A.; Cutoiu, D.; Gugiu, M.
2002-01-01
The collision of an electron with the atomic electronic core or the scattering of a nucleon on the atomic nucleus, usually, result into multiparticle excitations producing a resonance of a compound system, followed by its decay in reaction channels. Both in the electron-atom collisions and in nucleon-nucleus reactions, these multichannel resonances are described by poles of all R-Matrix elements. The resonances originating in single particle states, either in electron-atom collision or in nucleon-nucleus scattering, are approached in quite different descriptions. For example, the single-particle resonance in nuclear scattering is described, in R-Matrix Theory, by a perturbative method due to Bloch. The original single-nucleon state overlaps the actual states of the nucleus, resulting into a micro-giant description of the single particle resonance. The spectroscopic aspects of the single particle state, mixed with actual nuclear states, are subject of nucleon (or single particle) Strength Function. The electron, involving single particle Rydberg state in an atomic collision, 'avoids' its wave function mixing with that of inner multielectron core, because it is spatially far-away located from that core. This process is usually described by the Multichannel Quantum Defect Theory (MQDT). In the electron-atom scattering rather the effect of inner multielectron core on Rydberg electrons is studied by means of a global parameter, historically called 'Quantum Defect'. Both these types of resonances have in common the preserving of the single-particle wave function in a complex system with multiparticle excitations. In this work one approaches description of single-particle (electron or nucleon) resonance in a multichannel system. The single particle multichannel resonances are not longer described by a R-Matrix pole (specific for resonances originating in multiparticle excitations) but rather by a natural method for incorporating a single particle state in R-Matrix Theory
Directory of Open Access Journals (Sweden)
K. A. Ramesh Kumar
2014-09-01
Full Text Available AlSiC is a metal matrix composite which comprises of aluminium matrix with silicon carbide particles. It is characterized by high thermal conductivity (180-200 W/m K, and its thermal expansion are attuned to match other important materials that finds enormous demand in industrial sectors. Although its application is very common, the physics behind the Al-SiC formation, functionality and behaviors are intricate owing to the temperature gradient of hundreds of degrees, over the volume, occurring on a time scale of a few seconds, involving multiple phases. In this study, various physical, metallurgical and numerical aspects such as equation of continuum for thermal, stress and deformation using finite element (FE matrix formulation, temperature dependent material properties, are analyzed. Modelling and simulation studies of Al/SiC composites are a preliminary attempt to view this research work from computational point of view.
International Nuclear Information System (INIS)
Itagaki, Masafumi; Sahashi, Naoki.
1997-01-01
The multiple reciprocity boundary element method has been applied to three-dimensional two-group neutron diffusion problems. A matrix-type boundary integral equation has been derived to solve the first and the second group neutron diffusion equations simultaneously. The matrix-type fundamental solutions used here satisfy the equation which has a point source term and is adjoint to the neutron diffusion equations. A multiple reciprocity method has been employed to transform the matrix-type domain integral related to the fission source into an equivalent boundary one. The higher order fundamental solutions required for this formulation are composed of a series of two types of analytic functions. The eigenvalue itself is also calculated using only boundary integrals. Three-dimensional test calculations indicate that the present method provides stable and accurate solutions for criticality problems. (author)
International Nuclear Information System (INIS)
Tian Lifang; Wen Mingfen; Li Linyan; Chen Jing
2009-01-01
Electrochemical method with salt as electrolyte has been studied to disintegrate the graphite matrix from the simulative high temperature gas-cooled reactor fuel elements. Ammonium nitrate was experimentally chosen as the appropriate electrolyte. The volume average diameter of disintegrated graphite fragments is about 100 μm and the maximal value is less than 900 μm. After disintegration, the weight of graphite is found to increase by about 20% without the release of a large amount of CO 2 probably owing to the partial oxidation to graphite in electrochemical process. The present work indicates that the improved electrochemical method has the potential to reduce the secondary nuclear waste and is a promising option to disintegrate graphite matrix from high temperature gas-cooled reactor spent fuel elements in the head-end of reprocessing.
DEFF Research Database (Denmark)
Bak, Keld L.; Jørgensen, Poul; Jensen, H.J.A.
1992-01-01
A new scheme for obtaining first-order nonadiabatic coupling matrix elements (FO-NACME) for multiconfigurational self-consistent-field (MCSCF) wave functions is presented. The FO-NACME are evaluated from residues of linear response functions. The residues involve the geometrical response of a ref......A new scheme for obtaining first-order nonadiabatic coupling matrix elements (FO-NACME) for multiconfigurational self-consistent-field (MCSCF) wave functions is presented. The FO-NACME are evaluated from residues of linear response functions. The residues involve the geometrical response...... to the full configuration interaction limit. Comparisons are made with state-averaged MCSCF results for MgH2 and finite-difference configuration interaction by perturbation with multiconfigurational zeroth-order wave function reflected by interactive process (CIPSI) results for BH....
On the evaluation of the U(3) content of the matrix elements of one-and two-body operators
International Nuclear Information System (INIS)
Vanagas, V.; Alcaras, J.A.C.
1991-09-01
An expression for the U(3) content of the matrix elements of one- and two-body operators in Elliott's basis is obtained. Three alternative ways of evaluating this content with increasing performance in computing time are presented. All of them allow an exact representation of that content in terms of integers, avoiding rounding errors in the computer codes. The role of dual bases in dealing with non-orthogonal bases is also clarified. (author)
The transition matrix element Agq(N) of the variable flavor number scheme at O(α3s)
International Nuclear Information System (INIS)
Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von
2014-01-01
We calculate the massive operator matrix element A (3) gq (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α 3 s ). A fist independent recalculation is performed for the contributions ∝ N F of the 3-loop anomalous dimension γ (2) gq (N).
Radiochemical separation and ICP-AES determination of some common metallic elements in ThO2 matrix
International Nuclear Information System (INIS)
Adya, V.C.; Hon, N.S.; Bangia, T.R.; Sastry, M.D.; Iyer, R.H.
1997-01-01
Radioactive tracer and also ICP-AES studies have been carried out to determine Al, Cd, Ca, Cr, Co, Cu, Mn, Mo and Pd in ThO 2 matrix after chemical separation. Di-2-ethyl-hexyl phosphoric acid/xylene/HNO 3 extraction system was used for quantitative separation of thorium. The recovery of elements as determined by tracers and ICP-AES was found to be quantitative within experimental error. (author). 3 refs., 1 tab
Institute of Scientific and Technical Information of China (English)
FAN Hong-Yi
2002-01-01
We show that the Wigner function W = Tr(△ρ) (an ensemble average of the density operator ρ, △ is theWigner operator) can be expressed as a matrix element of ρ in the entangled pure states. In doing so, converting fromquantum master equations to time-evolution equation of the Wigner functions seems direct and concise. The entangledstates are defined in the enlarged Fock space with a fictitious freedom.
SU(2) X SU(2) X U(1) basis for symmetric SO(6) representations: matrix elements of the generators
International Nuclear Information System (INIS)
Piepenbring, R.; Silvestre-Brac, B.; Szymanski, Z.
1987-01-01
Matrix elements of the group generators for the symmetric irreducible representations of SO(6) are explicitly calculated in a closed form employing thedecomposition chain SO(6) is contained in SU(2) X SU(2) X U(1) (which is different from the well known Wigner supermultiplet scheme). The relation to the Gel'fand Tsetlin method using SO(6) contained in SO(5) up to ... SO(2) is indicated. An example of a physical application is given
The transition matrix element Agq(N) of the variable flavor number scheme at O(αs3)
International Nuclear Information System (INIS)
Ablinger, J.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; Manteuffel, A. von; Round, M.; Schneider, C.; Wißbrock, F.
2014-01-01
We calculate the massive unpolarized operator matrix element A gq (3) (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α s 3 ). A first independent recalculation is performed for the contributions ∝N F of the 3-loop anomalous dimension γ gq (2) (N)
Pairing fluctuation effects on the single-particle spectra for the superconducting state
International Nuclear Information System (INIS)
Pieri, P.; Pisani, L.; Strinati, G.C.
2004-01-01
Single-particle spectra are calculated in the superconducting state for a fermionic system with an attractive interaction, as functions of temperature and coupling strength from weak to strong. The fermionic system is described by a single-particle self-energy that includes pairing-fluctuation effects in the superconducting state. The theory reduces to the ordinary BCS approximation in weak coupling and to the Bogoliubov approximation for the composite bosons in strong coupling. Several features of the single-particle spectral function are shown to compare favorably with experimental data for cuprate superconductors
Semiempirical formulas for single-particle energies of neutrons and protons
International Nuclear Information System (INIS)
Lodhi, M.A.K.; Waak, B.T.
1978-01-01
The stepwise multiple linear regression technique has been used to analyze the single-particle energies of neutrons and protons in nuclei along the line of beta stability. Their regular and systematic trends lead to semiempirical model-independent formulas for single-particle energies of neutrons and protons in the bound nuclei as functions of nuclear parameters A and Z for given states specified by nl/sub j/. These formulas are almost as convenient as the harmonic oscillator energy formulas to use. The single-particle energies computed from these formulas have been compared with the experimental data and are found in reasonable agreement
Energy Technology Data Exchange (ETDEWEB)
Kiefer, René; Schad, Ariane; Roth, Markus [Kiepenheuer-Institut für Sonnenphysik, Schöneckstraße 6, D-79104 Freiburg (Germany)
2017-09-10
Where is the solar dynamo located and what is its modus operandi? These are still open questions in solar physics. Helio- and asteroseismology can help answer them by enabling us to study solar and stellar internal structures through global oscillations. The properties of solar and stellar acoustic modes are changing with the level of magnetic activity. However, until now, the inference on subsurface magnetic fields with seismic measures has been very limited. The aim of this paper is to develop a formalism to calculate the effect of large-scale toroidal magnetic fields on solar and stellar global oscillation eigenfunctions and eigenfrequencies. If the Lorentz force is added to the equilibrium equation of motion, stellar eigenmodes can couple. In quasi-degenerate perturbation theory, this coupling, also known as the direct effect, can be quantified by the general matrix element. We present the analytical expression of the matrix element for a superposition of subsurface zonal toroidal magnetic field configurations. The matrix element is important for forward calculations of perturbed solar and stellar eigenfunctions and frequency perturbations. The results presented here will help to ascertain solar and stellar large-scale subsurface magnetic fields, and their geometric configuration, strength, and change over the course of activity cycles.
Component tree analysis of cystovirus φ6 nucleocapsid Cryo-EM single particle reconstructions.
Directory of Open Access Journals (Sweden)
Lucas M Oliveira
Full Text Available The 3-dimensional structure of the nucleocapsid (NC of bacteriophage φ6 is described utilizing component tree analysis, a topological and geometric image descriptor. The component trees are derived from density maps of cryo-electron microscopy single particle reconstructions. Analysis determines position and occupancy of structure elements responsible for RNA packaging and transcription. Occupancy of the hexameric nucleotide triphosphorylase (P4 and RNA polymerase (P2 are found to be essentially complete in the NC. The P8 protein lattice likely fixes P4 and P2 in place during maturation. We propose that the viral procapsid (PC is a dynamic structural intermediate where the P4 and P2 can attach and detach until held in place in mature NCs. During packaging, the PC expands to accommodate the RNA, and P2 translates from its original site near the inner 3-fold axis (20 sites to the inner 5-fold axis (12 sites with excess P2 positioned inside the central region of the NC.
Measurement of ambient aerosols in northern Mexico City by single particle mass spectrometry
Directory of Open Access Journals (Sweden)
R. C. Moffet
2008-08-01
Full Text Available Continuous ambient measurements with aerosol time-of-flight mass spectrometry (ATOFMS were made in an industrial/residential section in the northern part of Mexico City as part of the Mexico City Metropolitan Area-2006 campaign (MCMA-2006. Results are presented for the period of 15–27 March 2006. The submicron size mode contained both fresh and aged biomass burning, aged organic carbon (OC mixed with nitrate and sulfate, elemental carbon (EC, nitrogen-organic carbon, industrial metal, and inorganic NaK inorganic particles. Overall, biomass burning and aged OC particle types comprised 40% and 31%, respectively, of the submicron mode. In contrast, the supermicron mode was dominated by inorganic NaK particle types (42% which represented a mixture of dry lake bed dust and industrial NaK emissions mixed with soot. Additionally, aluminosilicate dust, transition metals, OC, and biomass burning contributed to the supermicron particles. Early morning periods (2–6 a.m. showed high fractions of inorganic particles from industrial sources in the northeast, composed of internal mixtures of Pb, Zn, EC and Cl, representing up to 73% of the particles in the 0.2–3μm size range. A unique nitrogen-containing organic carbon (NOC particle type, peaking in the early morning hours, was hypothesized to be amines from local industrial emissions based on the time series profile and back trajectory analysis. A strong dependence on wind speed and direction was observed in the single particle types that were present during different times of the day. The early morning (3:30–10 a.m. showed the greatest contributions from industrial emissions. During mid to late mornings (7–11 a.m., weak northerly winds were observed along with the most highly aged particles. Stronger winds from the south picked up in the late morning (after 11 a.m., resulting in a decrease in the concentrations of the major aged particle types and an increase in the number fraction of fresh
Studies of the neutron single-particle structure of exotic nuclei at the HRIBF
International Nuclear Information System (INIS)
Thomas, J.S.; Bardayan, D.W.; Blackmon, J.C.; Cizewski, J.A.; Greife, U.; Gross, C.J.; Johnson, M.S.; Jones, K.L.; Kozub, R.L.; Liang, J.F.; Livesay, R.J.; Ma, Z.; Moazen, B.H.; Nesaraja, C.D.; Shapira, D.; Smith, M.S.
2004-01-01
The study of neutron single-particle strengths in neutron-rich nuclei is of interest for nuclear structure and nuclear astrophysics. The distribution of single-particle strengths constrains the effective Hamiltonian and pairing interactions and determines neutron interaction rates that are crucial for understanding the synthesis of heavy nuclei in supernovae via the rapid neutron capture process. Particularly important are the neutron single-particle levels in nuclei near closed neutron shells. Radioactive ion beams from the Holifield Radioactive Ion Beam Facility have been used to study (d,p) reactions in inverse kinematics in order to probe neutron single-particle states in exotic nuclei. The results of a measurement with a 82 Ge beam will be presented
Gates, S. James; Kang, Lucas; Kessler, David S.; Korotkikh, Vadim
2018-04-01
A Gadget, more precisely a scalar Gadget, is defined as a mathematical calculation acting over a domain of one or more adinkra graphs and whose range is a real number. A 2010 work on the subject of automorphisms of adinkra graphs, implied the existence of multiple numbers of Gadgets depending on the number of colors under consideration. For four colors, this number is two. In this work, we verify the existence of a second such Gadget and calculate (both analytically and via explicit computer-enabled algorithms) its 1,358,954,496 matrix elements over 36,864 minimal valise adinkras related to the Coxeter Group BC4.
DEFF Research Database (Denmark)
Löschner, Katrin; Navratilova, Jana; Købler, Carsten
2013-01-01
of the AgNPs took place during the sample preparation stage. The digestate was injected into the asymmetric flow field flow fractionation (AF(4)) -ICP-MS system, which enabled fractionation of nanoparticles from the remaining meat matrix, and resulted in one large peak in the fractograms as well as two...... smaller peaks eluting close to the void volume. The recovery of silver contained in the large AgNP peak was around 80 %. Size determination of AgNPs in the meat matrix, based on external size calibration of the AF(4) channel, was hampered by non-ideal (early elution) behavior of the AgNPs. Single particle...
International Nuclear Information System (INIS)
Kim, Jeong Soo; Kim, Moon Kyum
2012-01-01
In this study, finite element analysis of beam on elastic foundation, which received great attention of researchers due to its wide applications in engineering, is performed for estimating dynamic responses of shallow foundation using exact stiffness matrix. First, element stiffness matrix based on the closed solution of beam on elastic foundation is derived. Then, we performed static finite element analysis included exact stiffness matrix numerically, comparing results from the analysis with some exact analysis solutions well known for verification. Finally, dynamic finite element analysis is performed for a shallow foundation structure under rectangular pulse loading using trapezoidal method. The dynamic analysis results exist in the reasonable range comparing solution of single degree of freedom problem under a similar condition. The results show that finite element analysis using exact stiffness matrix is evaluated as a good tool of estimating the dynamic response of structures on elastic foundation.
Limiting factors in single particle cryo electron tomography
Directory of Open Access Journals (Sweden)
Mikhail Kudryashev
2012-07-01
Full Text Available Modern methods of cryo electron microscopy and tomography allow visualization of protein nanomachines in their native state at the nanometer scale. Image processing methods including sub-volume averaging applied to repeating macromolecular elements within tomograms allow exploring their structures within the native context of the cell, avoiding the need for protein isolation and purification. Today, many different data acquisition protocols and software solutions are available to researchers to determine average structures of macromolecular complexes and potentially to classify structural intermediates. Here, we list the density maps reported in the literature, and analyze each structure for the chosen instrumental settings, sample conditions, main processing steps, and obtained resolution. We present conclusions that identify factors currently limiting the resolution gained by this approach.
Consolidation effects on tensile properties of an elemental Al matrix composite
Energy Technology Data Exchange (ETDEWEB)
Tang, F. [Building 4515, MS 6064, Metals and Ceramics Division, Oak Ridge National Lab, Oak Ridge, TN 37831 (United States)]. E-mail: tangf@ornl.gov; Meeks, H. [Ceracon Inc., 5150 Fairoaks Blvd. 01-330, Carmichael, CA 95628 (United States); Spowart, J.E. [UES Incorporated, AFRL/MLLM Building 655, 2230 Tenth St. Suite 1, Wright-Patterson AFB, OH 45433 (United States); Gnaeupel-Herold, T. [NIST Center for Neutron Research, 100 Bureau Dr. Stop 8562, Gaithersburg, MD 20899-8562 (United States); Prask, H. [NIST Center for Neutron Research, 100 Bureau Dr. Stop 8562, Gaithersburg, MD 20899-8562 (United States); Anderson, I.E. [Materials and Engineering Physics Program, Ames Laboratory, Iowa State University, Ames, IA 50011 (United States)
2004-11-25
In a simplified composite design, an unalloyed Al matrix was reinforced by spherical Al-Cu-Fe alloy particles (30 vol.%), using either commercial purity (99.7%) or high purity (99.99%) fine powders (diameter < 10 {mu}m). This composite material was consolidated by either vacuum hot pressing (VHP) or quasi-isostatic forging. The spatial distribution of reinforcement particles in both VHP and forged samples was shown to be almost the same by quantitative characterization with a multi-scale area fraction analysis technique. The tensile properties of all composite samples were tested and the forged materials showed significantly higher strength, while the elastic modulus values of all composite materials were close to the upper bound of theoretical predictions. Neutron diffraction measurements showed that there were high compressive residual stresses in the Al matrix of the forged samples and relatively low Al matrix residual stresses (predominantly compressive) in the VHP samples. By tensile tests and neutron diffraction measurements of the forged samples after annealing, it was shown that the high compressive residual stresses in the Al matrix were relieved and that tensile strength was also reduced to almost the same level as that of the VHP samples. Therefore, it was deduced that increased compressive residual stresses and enhanced dislocation densities in the forged composites raised the tensile strength to higher values than those of the VHP composites.
Models based on multichannel R-matrix theory for evaluating light element reactions
International Nuclear Information System (INIS)
Dodder, D.C.; Hale, G.M.; Nisley, R.A.; Witte, K.; Young, P.G.
1975-01-01
Multichannel R-matrix theory has been used as a basis for models for analysis and evaluation of light nuclear systems. These models have the characteristic that data predictions can be made utilizing information derived from other reactions related to the one of primary interest. Several examples are given where such an approach is valid and appropriate. (auth.)
Standard error propagation in R-matrix model fitting for light elements
International Nuclear Information System (INIS)
Chen Zhenpeng; Zhang Rui; Sun Yeying; Liu Tingjin
2003-01-01
The error propagation features with R-matrix model fitting 7 Li, 11 B and 17 O systems were researched systematically. Some laws of error propagation were revealed, an empirical formula P j = U j c / U j d = K j · S-bar · √m / √N for describing standard error propagation was established, the most likely error ranges for standard cross sections of 6 Li(n,t), 10 B(n,α0) and 10 B(n,α1) were estimated. The problem that the standard error of light nuclei standard cross sections may be too small results mainly from the R-matrix model fitting, which is not perfect. Yet R-matrix model fitting is the most reliable evaluation method for such data. The error propagation features of R-matrix model fitting for compound nucleus system of 7 Li, 11 B and 17 O has been studied systematically, some laws of error propagation are revealed, and these findings are important in solving the problem mentioned above. Furthermore, these conclusions are suitable for similar model fitting in other scientific fields. (author)
The extracellular matrix - the under-recognized element in lung disease?
Burgess, Janette K.; Mauad, Thais; Tjin, Gavin; Karlsson, Jenny C.; Westergren-Thorsson, Gunilla
2016-01-01
The lung is composed of airways and lung parenchyma, and the extracellular matrix (ECM) contains the main building blocks of both components. The ECM provides physical support and stability to the lung, and as such it has in the past been regarded as an inert structure. More recent research has
Kalita, Viktor M.; Snarskii, Andrei A.; Shamonin, Mikhail; Zorinets, Denis
2017-03-01
The influence of an external magnetic field on the static shear strain and the effective shear modulus of a magnetoactive elastomer (MAE) is studied theoretically in the framework of a recently introduced approach to the single-particle magnetostriction mechanism [V. M. Kalita et al., Phys. Rev. E 93, 062503 (2016), 10.1103/PhysRevE.93.062503]. The planar problem of magnetostriction in an MAE with magnetically soft inclusions in the form of a thin disk (platelet) having the magnetic anisotropy in the plane of this disk is solved analytically. An external magnetic field acts with torques on magnetic filler particles, creates mechanical stresses in the vicinity of inclusions, induces shear strain, and increases the effective shear modulus of these composite materials. It is shown that the largest effect of the magnetic field on the effective shear modulus should be expected in MAEs with soft elastomer matrices, where the shear modulus of the matrix is less than the magnetic anisotropy constant of inclusions. It is derived that the effective shear modulus is nonlinearly dependent on the external magnetic field and approaches the saturation value in magnetic fields exceeding the field of particle anisotropy. It is shown that model calculations of the effective shear modulus correspond to a phenomenological definition of effective elastic moduli and magnetoelastic coupling constants. The obtained theoretical results compare well with known experimental data. Determination of effective elastic coefficients in MAEs and their dependence on magnetic field is discussed. The concentration dependence of the effective shear modulus at higher filler concentrations has been estimated using the method of Padé approximants, which predicts that both the absolute and relative changes of the magnetic-field-dependent effective shear modulus will significantly increase with the growing concentration of filler particles.
International Nuclear Information System (INIS)
Abdolsalami, F.; Abdolsalami, M.; Perez, L.; Gomez, P.
1995-01-01
The authors have applied the finite-element method to electron-molecule collision with the exchange effect implemented rigorously. All the calculations are done in the body-frame within the fixed-nuclei approximation, where the exact treatment of exchange as a nonlocal effect results in a set of coupled integro-differential equations. The method is applied to e-H 2 and e-N 2 scatterings and the cross sections obtained are in very good agreement with the corresponding results the authors have generated from the linear-algebraic approach. This confirms the significant difference observed between their results generated by linear-algebraic method and the previously published e-N 2 cross sections. Their studies show that the finite-element method is clearly superior to the linear-algebraic approach in both memory usage and CPU time especially for large systems such as e-N 2 . The system coefficient matrix obtained from the finite-element method is often sparse and smaller in size by a factor of 12 to 16, compared to the linear-algebraic technique. Moreover, the CPU time required to obtain stable results with the finite-element method is significantly smaller than the linear-algebraic approach for one incident electron energy. The usage of computer resources in the finite-element method can even be reduced much further when (1) scattering calculations involving multiple electron energies are performed in one computer run and (2) exchange, which is a short range effect, is approximated by a sparse matrix. 17 refs., 7 figs., 5 tabs
Fixation of actinide elements into zeolites/zeotypes and Flexcrete-cement matrix
International Nuclear Information System (INIS)
Amini, S.; Dyer, A.; Durrani, S.K.
1993-01-01
The leaching behavior of α-emitter radionuclides (uranium and americium) from zeolite-L and the zeotype (SAPO-34) in a Flexcrete-cement matrix were examined by static and dynamic methods using 0.005M CaCl 2 and synthetic ground water as leachants. The leaching rates of UO 2 2+ were found to be higher by about ten orders of magnitude than those of Am 3+ for both zeolite-L and SAPO-34 in the cement matrix. The static and dynamic leaching rates of UO 2 2+ for SAPO-34 in CaCl 2 and synthetic ground water were ten orders of magnitude lower than those for L. SAPO-34 showed good selectivity for uranium at pH 2-3.5 and L was usefully selective for Am 3+ . Distribution coefficients of Am 3+ and UO 2 2+ increased with equilibrium pH. (author) 20 refs.; 2 figs.; 4 tabs
Chen, Yang; Wenger, John C; Yang, Fumo; Cao, Junji; Huang, Rujin; Shi, Guangming; Zhang, Shumin; Tian, Mi; Wang, Huanbo
2017-09-01
A Single Particle Aerosol Mass Spectrometer (SPAMS) was deployed in the urban area of Chongqing to characterize the particles present during a severe particulate pollution event that occurred in winter 2014-2015. The measurements were made at a time when residents engaged in traditional outdoor meat smoking activities to preserve meat before the Chinese Spring Festival. The measurement period was predominantly characterized by stagnant weather conditions, highly elevated levels of PM 2.5 , and low visibility. Eleven major single particle types were identified, with over 92.5% of the particles attributed to biomass burning emissions. Most of the particle types showed appreciable signs of aging in the stagnant air conditions. To simulate the meat smoking activities, a series of controlled smoldering experiments was conducted using freshly cut pine and cypress branches, both with and without wood logs. SPAMS data obtained from these experiments revealed a number of biomass burning particle types, including an elemental and organic carbon (ECOC) type that proved to be the most suitable marker for meat smoking activities. The traditional activity of making preserved meat in southwestern China is shown here to be a major source of particulate pollution. Improved measures to reduce emissions from the smoking of meat should be introduced to improve air quality in regions where smoking meat activity prevails. Copyright © 2017 Elsevier Ltd. All rights reserved.
Enhancement of single particle rare earth doped NaYF4: Yb, Er emission with a gold shell
International Nuclear Information System (INIS)
Li, Ling; Green, Kory; Hallen, Hans; Lim, Shuang Fang
2015-01-01
Upconversion of infrared light to visible light has important implications for bioimaging. However, the small absorption cross-section of rare earth dopants has limited the efficiency of these anti-Stokes nanomaterials. We present enhanced excitation absorption and single particle fluorescent emission of sodium yttrium fluoride, NaYF 4 : Yb, Er based upconverting nanoparticles coated with a gold nanoshell through surface plasmon resonance. The single gold-shell coated nanoparticles show enhanced absorption in the near infrared, enhanced total emission intensity, and increased green relative to red emission. We also show differences in enhancement between single and aggregated gold shell nanoparticles. The surface plasmon resonance of the gold-shell coated nanoparticle is shown to be dependent on the shell thickness. In contrast to other reported results, our single particle experimental observations are corroborated by finite element calculations that show where the green/red emission enhancement occurs, and what portion of the enhancement is due to electromagnetic effects. We find that the excitation enhancement and green/red emission ratio enhancement occurs at the corners and edges of the doped emissive core. (paper)
Off-diagonal helicity density matrix elements for vector mesons produced in polarized e+e- processes
International Nuclear Information System (INIS)
Anselmino, M.; Murgia, F.; Quintairos, P.
1999-04-01
Final state q q-bar interactions give origin to non zero values of the off-diagonal element ρ 1,-1 of the helicity density matrix of vector mesons produced in e + e - annihilations, as confirmed by recent OPAL data on φ, D * and K * 's. New predictions are given for ρ 1,-1 of several mesons produced at large x E and small p T - i.e. collinear with the parent jet - in the annihilation of polarized 3 + and 3 - , the results depend strongly on the elementary dynamics and allow further non trivial tests of the standard model. (author)
Swain, John; Taylor, Lucas
1997-01-01
The magnitudes of the CKM matrix elements $V_{td}$, $V_{ts}$, and $V_{tb}$ are determined for the first time without any assumptions of unitarity. The implications for the unitarity of the CKM matrix as a whole are discussed.
3-Loop massive O(T{sub 2}{sup F}) contributions to the DIS operator matrix element A{sub gg}
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hasselhuhn, A.; Round, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Inst. for Symbolic Computation (RISC); Manteuffel, A. von [Mainz Univ. (Germany). PRISMA Cluster of Excellence
2014-09-15
Contributions to heavy flavour transition matrix elements in the variable flavour number scheme are considered at 3-loop order. In particular a calculation of the diagrams with two equal masses that contribute to the massive operator matrix element A{sup (3)}{sub gg,Q} is performed. In the Mellin space result one finds finite nested binomial sums. In x-space these sums correspond to iterated integrals over an alphabet containing also square-root valued letters.
International Nuclear Information System (INIS)
Abdolsalami, F.; Abdolsalami, M.; Gomez, P.
1994-01-01
We have applied the finite-element method to electron-molecule collisions. All the calculations are done in the body frame within the fixed-nuclei approximation. A model potential, which is added to the static and polarization potential, has been used to represent the exchange effect. The method is applied to electron-H 2 scattering and the eigenphase sums and the cross sections obtained are in very good agreement with the corresponding results from the linear-algebraic approach. Finite-element calculations of the R matrix in the region where the static and exchange interactions are strong, however, has about one-half to one-fourth of the memory requirement of the linear-algebraic technique
International Nuclear Information System (INIS)
Pascual, J.
1987-01-01
An X-ray fluorescence method for determining trace elements in silicate rock samples was studied. The procedure focused on the application of the pertinent matrix corrections. Either the Compton peak or the reciprocal of the mass absorption coefficient of the sample was used as internal standard for this purpose. X-ray tubes with W or Cr anodes were employed, and the W Lβ and Cr Kα Compton intensities scattered by the sample were measured. The mass absorption coefficients at both sides of the absorption edge for Fe (1.658 and 1.936 A) were calculated. The elements Zr, Y, Rb, Zn, Ni, Cr and V were determined in 15 international reference rocks covering wide ranges of concentration. Relative mean errors were in many cases less than 10%. (author)
International Nuclear Information System (INIS)
Hwang, Hee Jin; Ro, Chul-Un
2006-01-01
In order to clearly elucidate whether Asian Dust particles experience chemical modification during long-range transport, it is necessary to characterize soil particles where Asian Dust particles originate. If chemical compositions of source soil particles are well characterized, then chemical compositions of Asian Dust particles collected outside source regions can be compared with those of source soil particles in order to find out the occurrence of chemical modification. Asian Dust particles are chemically and morphologically heterogeneous, and thus the average composition and the average aerodynamic diameter (obtainable by bulk analysis) are not much relevant if the chemical modifications of the particles must be followed. The major elemental composition and abundance of the particle types that are potential subjects of chemical modification can only be obtained using single-particle analysis. A single particle analytical technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize two certified reference materials (CRMs) for Asian Dust particles, which were collected from a loess plateau area and a desert of China. The CRMs were defined by bulk analyses to provide certified concentrations for 13 chemical elements. Using the low-Z particle EPMA technique, the concentrations of major chemical species such as aluminosilicates, SiO 2 , CaCO 3 , and carbonaceous species were obtained. Elemental concentrations obtained by the low-Z particle EPMA are close to the certified values, with considering that the single particle and bulk analyses employ very different approaches. There are still some discrepancies between those concentration values, resulting from analyses of particles with different sizes, different sample amounts analyzed, and uncertainties involved in the single particle analysis
Matrix units and Schur elements for the degenerate cyclotomic Hecke algebras
Zhao, Deke
2011-01-01
The paper uses the cellular basis of the (semi-simple) degenerate cyclotomic Hecke algebras to investigate these algebras exhaustively. As a consequence, we describe explicitly the "Young's seminormal form" and a orthogonal bases for Specht modules and determine explicitly the closed formula for the natural bilinear form on Specht modules and Schur elements for the degenerate cyclotomic Hekce algebras.
Directory of Open Access Journals (Sweden)
Kicošev Vesna
2015-01-01
Full Text Available Salt steppes and marshes represent the most valuable ecosystems in the world, providing numerous ecosystem services that are extremely vulnerable to anthropogenic influences. These types of habitat in the territory of Serbia are most dominant in Banat and a significant portion of them is under protection or in the process of becoming protected. The section surrounding the protected areas of Slano Kopovo Special Nature Reserve, Rusanda Nature Park and Okanj Bara Special Nature Reserve with the non-building area of Novi Bečej, Kumane, Melenci, Elemir and Taraš cadastral municipalities, has been chosen for the analysis. The aim of this paper was to assess the influence of specific anthropogenic factors on the elements of an ecological network using the analytical method that can generate the required results in a manner suitable for presentation to various stakeholders. To achieve this aim, the Leopold matrix model, used for assessing anthropogenic influence on the environment, has been chosen. The specificity of this issue of protecting and preserving elements of an ecological network resulted in the need to isolate and evaluate the factors affecting the preservation of habitats and functionality of ecosystems, unlike the concept of Leopold matrix, which treats all factors as equally important in the process of evaluation. Evaluation results indicate significant effects of historical, perennial manner of using the area and other resources in the non-building area.
Single-particle energies and density of states in density functional theory
van Aggelen, H.; Chan, G. K.-L.
2015-07-01
Time-dependent density functional theory (TD-DFT) is commonly used as the foundation to obtain neutral excited states and transition weights in DFT, but does not allow direct access to density of states and single-particle energies, i.e. ionisation energies and electron affinities. Here we show that by extending TD-DFT to a superfluid formulation, which involves operators that break particle-number symmetry, we can obtain the density of states and single-particle energies from the poles of an appropriate superfluid response function. The standard Kohn- Sham eigenvalues emerge as the adiabatic limit of the superfluid response under the assumption that the exchange- correlation functional has no dependence on the superfluid density. The Kohn- Sham eigenvalues can thus be interpreted as approximations to the ionisation energies and electron affinities. Beyond this approximation, the formalism provides an incentive for creating a new class of density functionals specifically targeted at accurate single-particle eigenvalues and bandgaps.
Energy Technology Data Exchange (ETDEWEB)
Cwik, T. [California Institute of Technology, Pasadena, CA (United States); Katz, D.S. [Cray Research, El Segundo, CA (United States)
1996-12-31
Finite element modeling has proven useful for accurately simulating scattered or radiated electromagnetic fields from complex three-dimensional objects whose geometry varies on the scale of a fraction of an electrical wavelength. An unstructured finite element model of realistic objects leads to a large, sparse, system of equations that needs to be solved efficiently with regard to machine memory and execution time. Both factorization and iterative solvers can be used to produce solutions to these systems of equations. Factorization leads to high memory requirements that limit the electrical problem size of three-dimensional objects that can be modeled. An iterative solver can be used to efficiently solve the system without excessive memory use and in a minimal amount of time if the convergence rate is controlled.
Directory of Open Access Journals (Sweden)
Prokhin Egor Anatol’evich
2016-10-01
Full Text Available In the modern conditions innovatization of construction is of great necessity, though it is associated with a number of problems of first of all institutional genesis. The development of green construction in Russia is on its first stages, though its necessity is growing according to the tendency for energy efficiency and sustainable development. The innovative process of ecological construction has a network model and requires its optimization with the aim of further development by advancing the institutional platform. The author proposed a conceptual scheme for an institutional platform of the innovative process of green construction and conducted systematization of institutional structures. The unique role of innovative and ecological institutes is substantiated. The author recommends an optimization method for institutional interaction of the subjects using the stakeholder theory and the theory of matrix games aimed at activation of innovative green technologies. Practical application of the offered algorithms and methods will allow increasing the efficiency of green construction development.
The determination of light elements in heavy matrix using proton induced X-ray emission
International Nuclear Information System (INIS)
Levenets, V.V.; Omel'nik, A.P.; Shchur, A.A.; Chernov, A.E.; Usikov, N.P.; Zats, A.V.
2007-01-01
In this report the possibility of determination of light impurities in heavy matrixes is studied using proton induced X-Ray emission. The wide-band X-ray emission filter made from pyrolytic graphite was used in spectrometric scheme of experiment. The results of studying of filter features in energy range of X-ray emission from 4 to 12 keV were presented. The possibilities were examined of application of pyrolytic graphite filter to modify the X-rays spectrum for determination of iron, using characteristic emission of K-series, and hafnium, using L-series, in substances on base of zirconium (glasses, alloys etc.). It was shown, that the using of similar filter allows to reach the significant improving of metrological characteristics of analysis of mentioned impurities: the limits of detection of iron and hafnium were lowered single-order of magnitude. (authors)
Evolution of Single-Particle Energies for N=9 Nuclei at Large N/Z
Directory of Open Access Journals (Sweden)
Wuosmaa A. H.
2014-03-01
Full Text Available We have studied the nucleus 14B using the 13B(d,p14B and 15C(d,3He14B reactions. The two reactions provide complementary information about the negative-parity 1s1/2 and 0d5/2 neutron single-particle states in 14B. The data from the (d,p reaction give neutron-spectroscopic strengths for these levels, and the (d,3He results confirm the existence of a broad 2- excited state suggested in the literature. Together these results provide estimates of the sd-shell neutron effective single-particle energies in 14B.
Quantum chaos in nuclear single-particle motion and damping of giant resonances
International Nuclear Information System (INIS)
Pal, Santanu; Mukhopadhyay, Tapan
1995-01-01
The spectral statistics of single particle motion in deformed cavities with axial symmetry are presented. The single particle motion in the cavities considered are non-integrable and the systematics of the fluctuation measures of the spectra reveal a transition from regular to chaotic regime in the corresponding classical systems. Quantitative estimate of the degree of chaos enables us to introduce a correction factor to the one-body wall formula for the damping widths of isoscalar giant resonances. The damping widths calculated with this correction factor give much better agreement with experimental values than earlier calculations of one-body damping widths. (author). 21 refs., 5 figs
Single particle dynamics of many-body systems described by Vlasov-Fokker-Planck equations
International Nuclear Information System (INIS)
Frank, T.D.
2003-01-01
Using Langevin equations we describe the random walk of single particles that belong to particle systems satisfying Vlasov-Fokker-Planck equations. In doing so, we show that Haissinski distributions of bunched particles in electron storage rings can be derived from a particle dynamics model
A different approach to obtain Mayer’s extension to stationary single particle Wigner distribution
International Nuclear Information System (INIS)
Bose, Anirban; Janaki, M. S.
2012-01-01
It is shown that the stationary collisionless single-particle Wigner equation in one dimension containing quantum corrections at the lowest order is satisfied by a distribution function that is similar in form to the Maxwellian distribution with an effective mass and a generalized potential. The distribution is used to study quantum corrections to electron hole solutions.
Single Particle Potential of a Σ Hyperon in Nuclear Matter. II Rearrangement Effects
International Nuclear Information System (INIS)
Dabrowski, J.
2000-01-01
The rearrangement contribution to the real part of the single particle potential of a Σ hyperon in nuclear matter, U Σ , is investigated. The isospin and spin dependent parts of U Σ are considered. Results obtained for four models of the Nijmegen baryon-baryon interaction are presented and discussed. (author)
Basic Evidence and Properties of Single-Particle States in Nuclei
Energy Technology Data Exchange (ETDEWEB)
Cindro, N. [Institute ' ' Rudjer Boskovic' ' , Zagreb, Yugoslavia (Croatia)
1970-07-15
1. Introduction: the shell-model orbitals; 2. Information about single-particle orbitals: a critical evaluation; 3. Experimental evidence: 3.1. The lead region; 3.2. The calcium region; 3.3. Nuclei far from closed shells; 4. Conclusion. (author)
DECAY MODES OF HIGH-LYING SINGLE-PARTICLE STATES IN PB-209
BEAUMEL, D; FORTIER, S; GALES, S; GUILLOT, J; LANGEVINJOLIOT, H; LAURENT, H; MAISON, JM; VERNOTTE, J; BORDEWIJK, JA; BRANDENBURG, S; KRASZNAHORKAY, A; CRAWLEY, GM; MASSOLO, CP; RENTERIA, M
The neutron decay of high-lying single-particle states in Pb-209 excited by means of the (alpha, He-3) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high-spin values of these states, inferred from previous inclusive experiments, are confirmed by the
Single-particle electron microscopy in the study of membrane protein structure.
De Zorzi, Rita; Mi, Wei; Liao, Maofu; Walz, Thomas
2016-02-01
Single-particle electron microscopy (EM) provides the great advantage that protein structure can be studied without the need to grow crystals. However, due to technical limitations, this approach played only a minor role in the study of membrane protein structure. This situation has recently changed dramatically with the introduction of direct electron detection device cameras, which allow images of unprecedented quality to be recorded, also making software algorithms, such as three-dimensional classification and structure refinement, much more powerful. The enhanced potential of single-particle EM was impressively demonstrated by delivering the first long-sought atomic model of a member of the biomedically important transient receptor potential channel family. Structures of several more membrane proteins followed in short order. This review recounts the history of single-particle EM in the study of membrane proteins, describes the technical advances that now allow this approach to generate atomic models of membrane proteins and provides a brief overview of some of the membrane protein structures that have been studied by single-particle EM to date. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Single-particle thermal diffusion of charged colloids: Double-layer theory in a temperature gradient
Dhont, J.K.G.; Briels, Willem J.
2008-01-01
The double-layer contribution to the single-particle thermal diffusion coefficient of charged, spherical colloids with arbitrary double-layer thickness is calculated and compared to experiments. The calculation is based on an extension of the Debye-Hückel theory for the double-layer structure that
Czech Academy of Sciences Publication Activity Database
Pacáková, Barbara; Mantlíková, Alice; Nižňanský, D.; Kubíčková, Simona; Vejpravová, Jana
2016-01-01
Roč. 28, č. 20 (2016), 1-11, č. článku 206004. ISSN 0953-8984 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:68378271 Keywords : magnetic nanoparticles * single-particle anisotropy * dipolar energy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.649, year: 2016
Summary report of the group on single-particle nonlinear dynamics
International Nuclear Information System (INIS)
Axinescu, S.; Bartolini, R.; Bazzani, A.
1996-10-01
This report summarizes the research on single-particle nonlinear beam dynamics. It discusses the following topics: analytical and semi-analytical tools; early prediction of the dynamic aperture; how the results are commonly presented; Is the mechanism of the dynamic aperture understand; ripple effects; and beam-beam effects
International Nuclear Information System (INIS)
Lee, Young Woo; Cho, Moon Sung
2011-01-01
The fuel element for HTGR is manufactured by mixing coated fuel particles with matrix graphite powder and forming into either pebble type or cylindrical type compacts depending on their use in different HTGR cores. The coated fuel particle, the so-called TRISO particle, consists of 500-μm spherical UO 2 particles coated with the low density buffer Pyrolytic Carbon (PyC) layer, the inner and outer high density PyC layer and SiC layer sandwiched between the two inner and outer PyC layers. The coated TRISO particles are mixed with a matrix graphite powder properly prepared and pressed into a spherical shape or a cylindrical compact finally heat-treated at about 1900 .deg. C. These fuel elements can have different sizes and forms of compact. The basic steps for manufacturing a fuel element include preparation of graphite matrix powder, overcoating the fuel particles, mixing the fuel particles with a matrix powder, carbonizing green compact, and the final high-temperature heat treatment of the carbonized fuel compact. In order to develop a fuel compact fabrication technology, it is important to develop a technology to prepare the matrix graphite powder (MGP) with proper characteristics, which has a strong influence on further steps and the material properties of fuel element. In this work, the milling behavior of matrix graphite powder mixture with different binder materials and their contents was investigated by analyzing the change in particle size distribution with different milling time
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Goedicke, A. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Theoretische Teilchenphysik; Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC)
2017-12-15
We report on our latest results in the calculation of the two-mass contributions to 3-loop operator matrix elements (OMEs). These OMEs are needed to compute the corresponding contributions to the deep-inelastic scattering structure functions and to generalize the variable flavor number scheme by including both charm and bottom quarks. We present the results for the non-singlet and A{sub gq,Q} OMEs, and compare the size of their contribution relative to the single mass case. Results for the gluonic OME A{sub gg,Q} are given in the physical case, going beyond those presented in a previous publication where scalar diagrams were computed. We also discuss our recently published two-mass contribution to the pure singlet OME, and present an alternative method of calculating the corresponding diagrams.
International Nuclear Information System (INIS)
Kirchbach, M.
1986-01-01
In this paper the experience in extracting the value of the weak pion-nucleon coupling constant f/sub π//sup l/ from the parity-mixing matrix element + , T = 1; 1.042 MeV | V/sub PNC/ | O - , T = 0; 1.081 MeV> in 18 F is summarized with the aim to reveal some sources of uncertainties of the models exploited. We show that beyond of the long wavelenth approximation and in treating non-soft pion corrections to the two-body nuclear chiral charge density an upper bound for f/sub π//sup l/ is obtained which is about two times smaller as compared to results of previous analyses of similar character. Finally, we accentuate on the importance of the heavy-meson exchanges in the weak NN-potential for understanding recent measurement results of f/sub π//sup l/ which strongly deviate from earlier data. (author)
International Nuclear Information System (INIS)
Sen, S.; Balasubramaniam, R.; Sethuraman, R.
1996-01-01
The molar volume difference between the matrix and the precipitate phases in the case of solid state phase transformations results in the creation of stain energy in the system due to the misfit strains. A finite element model based on the initial strain approach is proposed to evaluate elasto-plastic accommodation energies during solid state transformation. The three-dimensional axisymmetric model has been used to evaluate energies as a function of transformation for α-β hydrogen transformations in the Nb-H system. The transformation has been analyzed for the cases of transformation progressing both from the center to surface and from the surface to center of the system. The effect of plastic deformation has been introduced to make the model realistic, specifically to the Nb-NbH phase transformation which involves a 4% linear misfit strain. It has been observed that plastic deformation reduces the strain energies compared to the linear elastic analysis
International Nuclear Information System (INIS)
Karaziya, R.I.; Rudzikajte, L.S.
1988-01-01
The general method to obtain the explicit expressions for sums of the matrix elements of Hamiltonian and transition operators has been extended. It can be used for determining the main characteristics of atomic spectra, such as the mean energy, the variance, the asymmetry coefficient, etc., as well as for the average quantities which describe the configuration mixing. By mean of this method the formula for the variance of the emission spectrum has been derived. It has been shown that this quantity of the emission spectrum can be expressed by the variances of the energy spectra of the initial and final configurations and by additional terms, caused by the distribution of the intensity in spectrum
Chegel, Raad; Behzad, Somayeh
2014-02-01
We have studied the electronic structure and dipole matrix element, D, of carbon nanotubes (CNTs) under magnetic field, using the third nearest neighbor tight binding model. It is shown that the 1NN and 3NN-TB band structures show differences such as the spacing and mixing of neighbor subbands. Applying the magnetic field leads to breaking the degeneracy behavior in the D transitions and creates new allowed transitions corresponding to the band modifications. It is found that |D| is proportional to the inverse tube radius and chiral angle. Our numerical results show that amount of filed induced splitting for the first optical peak is proportional to the magnetic field by the splitting rate ν11. It is shown that ν11 changes linearly and parabolicly with the chiral angle and radius, respectively.
Henry, Jackson; Blair, Enrique P.
2018-02-01
Mixed-valence molecules provide an implementation for a high-speed, energy-efficient paradigm for classical computing known as quantum-dot cellular automata (QCA). The primitive device in QCA is a cell, a structure with multiple quantum dots and a few mobile charges. A single mixed-valence molecule can function as a cell, with redox centers providing quantum dots. The charge configuration of a molecule encodes binary information, and device switching occurs via intramolecular electron transfer between dots. Arrays of molecular cells adsorbed onto a substrate form QCA logic. Individual cells in the array are coupled locally via the electrostatic electric field. This device networking enables general-purpose computing. Here, a quantum model of a two-dot molecule is built in which the two-state electronic system is coupled to the dominant nuclear vibrational mode via a reorganization energy. This model is used to explore the effects of the electronic inter-dot tunneling (coupling) matrix element and the reorganization energy on device switching. A semi-classical reduction of the model also is made to investigate the competition between field-driven device switching and the electron-vibrational self-trapping. A strong electron-vibrational coupling (high reorganization energy) gives rise to self-trapping, which inhibits the molecule's ability to switch. Nonetheless, there remains an expansive area in the tunneling-reorganization phase space where molecules can support adequate tunneling. Thus, the relationship between the tunneling matrix element and the reorganization energy affords significant leeway in the design of molecules viable for QCA applications.
Kramer, Harald; Michaely, Henrik J; Matschl, Volker; Schmitt, Peter; Reiser, Maximilian F; Schoenberg, Stefan O
2007-06-01
Recent developments in hard- and software help to significantly increase image quality of magnetic resonance angiography (MRA). Parallel acquisition techniques (PAT) help to increase spatial resolution and to decrease acquisition time but also suffer from a decrease in signal-to-noise ratio (SNR). The movement to higher field strength and the use of dedicated angiography coils can further increase spatial resolution while decreasing acquisition times at the same SNR as it is known from contemporary exams. The goal of our study was to compare the image quality of MRA datasets acquired with a standard matrix coil in comparison to MRA datasets acquired with a dedicated peripheral angio matrix coil and higher factors of parallel imaging. Before the first volunteer examination, unaccelerated phantom measurements were performed with the different coils. After institutional review board approval, 15 healthy volunteers underwent MRA of the lower extremity on a 32 channel 3.0 Tesla MR System. In 5 of them MRA of the calves was performed with a PAT acceleration factor of 2 and a standard body-matrix surface coil placed at the legs. Ten volunteers underwent MRA of the calves with a dedicated 36-element angiography matrix coil: 5 with a PAT acceleration of 3 and 5 with a PAT acceleration factor of 4, respectively. The acquired volume and acquisition time was approximately the same in all examinations, only the spatial resolution was increased with the acceleration factor. The acquisition time per voxel was calculated. Image quality was rated independently by 2 readers in terms of vessel conspicuity, venous overlay, and occurrence of artifacts. The inter-reader agreement was calculated by the kappa-statistics. SNR and contrast-to-noise ratios from the different examinations were evaluated. All 15 volunteers completed the examination, no adverse events occurred. None of the examinations showed venous overlay; 70% of the examinations showed an excellent vessel conspicuity
2016-01-01
The problem of multi-scale modelling of damage development in a SiC ceramic fibre-reinforced SiC matrix ceramic composite tube is addressed, with the objective of demonstrating the ability of the finite-element microstructure meshfree (FEMME) model to introduce important aspects of the microstructure into a larger scale model of the component. These are particularly the location, orientation and geometry of significant porosity and the load-carrying capability and quasi-brittle failure behaviour of the fibre tows. The FEMME model uses finite-element and cellular automata layers, connected by a meshfree layer, to efficiently couple the damage in the microstructure with the strain field at the component level. Comparison is made with experimental observations of damage development in an axially loaded composite tube, studied by X-ray computed tomography and digital volume correlation. Recommendations are made for further development of the model to achieve greater fidelity to the microstructure. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242308
International Nuclear Information System (INIS)
Holas, A.; Cinal, M.
2005-01-01
Three approximate exchange potentials of high accuracy v x Y (r), Y=A,B,C, for the density-functional theory applications are obtained by replacing the matrix elements of the exact potential between the Kohn-Sham (KS) orbitals with such elements of the Fock exchange operator (within the virtual-occupied subset only) in three representations found for any local potential. A common identity is the base of these representations. The potential v x C happens to be the same as that derived by Harbola and Sahni, and v x A as that derived by Gritsenko and Baerends, and Della Sala and Goerling. The potentials obtained can be expressed in terms of occupied KS orbitals only. At large r, their asymptotic form -1/r is the same as that of the exact potential. The high quality of these three approximations is demonstrated by direct comparison with the exact potential and using various consistency tests. A common root established for the three approximations could be helpful in finding new and better approximations via modification of identities employed in the present investigation
International Nuclear Information System (INIS)
Nozawa, Tomohiro; Arakawa, Yasuhiko
2014-01-01
The intraband transitions which are essential for quantum dot intermediate band solar cells (QD IBSCs) are theoretically investigated by estimating the matrix elements from a ground bound state, which is often regarded as an intermediate band (IB), to conduction band (CB) states for a structure with a quantum dot (QD) embedded in a matrix (a QD/matrix structure). We have found that the QD pushes away the electron envelope functions (probability densities) from the QD region in almost all quantum states above the matrix CB minimum. As a result, the matrix elements of the intraband transitions in the QD/matrix structure are largely reduced, compared to those calculated assuming the envelope functions of free electrons (i.e., plane-wave envelope functions) in a matrix structure as the final states of the intraband transitions. The result indicates the strong influence of the QD itself on the intraband transitions from the IB to the CB states in QD IBSC devices. This work will help in better understanding the problem of the intraband transitions and give new insight, that is, engineering of quantum states is indispensable for the realization of QD IBSCs with high solar energy conversion efficiencies. (paper)
Braun, H; Erriquez, O; Martyn, H U; Renton, P B; Romano, F; Vilain, P; Waldren, D
1976-01-01
The matrix element of the three pion decay mode of the kaon is expressed in terms of Mandelstam variables. An analysis of the Dalitz plot density distribution gives information on the parameters of the expression. From an analysis of the decays of stopping K/sup +/ mesons involving neutral pions in the CERN heavy-liquid bubble chamber filled with a propane ethane mixture, it is concluded that the energy dependence of the decay matrix element is compatible with a linear behaviour. (3 refs).
Directory of Open Access Journals (Sweden)
Eldad Kepten
Full Text Available Single particle tracking is an essential tool in the study of complex systems and biophysics and it is commonly analyzed by the time-averaged mean square displacement (MSD of the diffusive trajectories. However, past work has shown that MSDs are susceptible to significant errors and biases, preventing the comparison and assessment of experimental studies. Here, we attempt to extract practical guidelines for the estimation of anomalous time averaged MSDs through the simulation of multiple scenarios with fractional Brownian motion as a representative of a large class of fractional ergodic processes. We extract the precision and accuracy of the fitted MSD for various anomalous exponents and measurement errors with respect to measurement length and maximum time lags. Based on the calculated precision maps, we present guidelines to improve accuracy in single particle studies. Importantly, we find that in some experimental conditions, the time averaged MSD should not be used as an estimator.
Single-particle properties of the Hubbard model in a novel three-pole approximation
Di Ciolo, Andrea; Avella, Adolfo
2018-05-01
We study the 2D Hubbard model using the Composite Operator Method within a novel three-pole approximation. Motivated by the long-standing experimental puzzle of the single-particle properties of the underdoped cuprates, we include in the operatorial basis, together with the usual Hubbard operators, a field describing the electronic transitions dressed by the nearest-neighbor spin fluctuations, which play a crucial role in the unconventional behavior of the Fermi surface and of the electronic dispersion. Then, we adopt this approximation to study the single-particle properties in the strong coupling regime and find an unexpected behavior of the van Hove singularity that can be seen as a precursor of a pseudogap regime.
Single-particle model of a strongly driven, dense, nanoscale quantum ensemble
DiLoreto, C. S.; Rangan, C.
2018-01-01
We study the effects of interatomic interactions on the quantum dynamics of a dense, nanoscale, atomic ensemble driven by a strong electromagnetic field. We use a self-consistent, mean-field technique based on the pseudospectral time-domain method and a full, three-directional basis to solve the coupled Maxwell-Liouville equations. We find that interatomic interactions generate a decoherence in the state of an ensemble on a much faster time scale than the excited-state lifetime of individual atoms. We present a single-particle model of the driven, dense ensemble by incorporating interactions into a dephasing rate. This single-particle model reproduces the essential physics of the full simulation and is an efficient way of rapidly estimating the collective dynamics of a dense ensemble.
Inequivalence of single-particle and population lifetimes in a cuprate superconductor
Energy Technology Data Exchange (ETDEWEB)
Yang, Shuolong [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Sobota, J. A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Leuenberger, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); He, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Hashimoto, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lu, D. H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Eisaki, H. [National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan); Kirchmann, P. S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
2015-06-15
We study optimally doped Bi-2212 (T_{c}=96 K) using femtosecond time- and angle-resolved photoelectron spectroscopy. Energy-resolved population lifetimes are extracted and compared with single-particle lifetimes measured by equilibrium photoemission. The population lifetimes deviate from the single-particle lifetimes in the low excitation limit by 1–2 orders of magnitude. Fundamental considerations of electron scattering unveil that these two lifetimes are in general distinct, yet for systems with only electron-phonon scattering they should converge in the low-temperature, low-fluence limit. As a result, the qualitative disparity in our data, even in this limit, suggests that scattering channels beyond electron-phonon interactions play a significant role in the electron dynamics of cuprate superconductors.
International Nuclear Information System (INIS)
Daniel, Jonathan; Blanchard-Desce, Mireille; Godin, Antoine G; Palayret, Matthieu; Lounis, Brahim; Cognet, Laurent
2016-01-01
Based on an original molecular-based design, we present bright and photostable fluorescent organic nanoparticles (FONs) showing excellent colloidal stability in various aqueous environments. Complementary near-infrared emitting and green emitting FONs were prepared using a simple, fast and robust protocol. Both types of FONs could be simultaneously imaged at the single-particle level in solution as well as in biological environments using a monochromatic excitation and a dual-color fluorescence microscope. No evidence of acute cytotoxicity was found upon incubation of live cells with mixed solutions of FONs, and both types of nanoparticles were found internalized in the cells where their motion could be simultaneously tracked at video-rate up to minutes. These fluorescent organic nanoparticles open a novel non-toxic alternative to existing nanoparticles for imaging biological structures, compatible with live-cell experiments and specially fitted for multicolor single particle tracking. (paper)
Radiative capture of nucleons at astrophysical energies with single-particle states
International Nuclear Information System (INIS)
Huang, J.T.; Bertulani, C.A.; Guimaraes, V.
2010-01-01
Radiative capture of nucleons at energies of astrophysical interest is one of the most important processes for nucleosynthesis. The nucleon capture can occur either by a compound nucleus reaction or by a direct process. The compound reaction cross sections are usually very small, especially for light nuclei. The direct capture proceeds either via the formation of a single-particle resonance or a non-resonant capture process. In this work we calculate radiative capture cross sections and astrophysical S-factors for nuclei in the mass region A<20 using single-particle states. We carefully discuss the parameter fitting procedure adopted in the simplified two-body treatment of the capture process. Then we produce a detailed list of cases for which the model works well. Useful quantities, such as spectroscopic factors and asymptotic normalization coefficients, are obtained and compared to published data.
Digital atom interferometer with single particle control on a discretized space-time geometry.
Steffen, Andreas; Alberti, Andrea; Alt, Wolfgang; Belmechri, Noomen; Hild, Sebastian; Karski, Michał; Widera, Artur; Meschede, Dieter
2012-06-19
Engineering quantum particle systems, such as quantum simulators and quantum cellular automata, relies on full coherent control of quantum paths at the single particle level. Here we present an atom interferometer operating with single trapped atoms, where single particle wave packets are controlled through spin-dependent potentials. The interferometer is constructed from a sequence of discrete operations based on a set of elementary building blocks, which permit composing arbitrary interferometer geometries in a digital manner. We use this modularity to devise a space-time analogue of the well-known spin echo technique, yielding insight into decoherence mechanisms. We also demonstrate mesoscopic delocalization of single atoms with a separation-to-localization ratio exceeding 500; this result suggests their utilization beyond quantum logic applications as nano-resolution quantum probes in precision measurements, being able to measure potential gradients with precision 5 x 10(-4) in units of gravitational acceleration g.
Single-particle spectra and magnetic field effects within precursor superconductivity
International Nuclear Information System (INIS)
Pieri, P.; Pisani, L.; Strinati, G.C.; Perali, A.
2004-01-01
We study the single-particle spectra below the superconducting critical temperature from weak to strong coupling within a precursor superconductivity scenario. The spectral-weight function is obtained from a self-energy that includes pairing-fluctuations within a continuum model representing the hot spots of the Brillouin zone. The effects of strong magnetic fields on the pseudogap temperature are also discussed within the same scenario
Single-particle cryo-electron microscopy of Rift Valley fever virus
Sherman, Michael B.; Freiberg, Alexander N.; Holbrook, Michael R.; Watowich, Stanley J.
2009-01-01
Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human veterinary pathogen causing acute hepatitis in ruminants and has the potential to Single-particle cryo-EM reconstruction of RVFV MP-12 hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on...
Single particle measurements and two particle interferometry results from CERN experiment NA44
International Nuclear Information System (INIS)
Simon-Gillo, J.
1994-01-01
CERN experiment NA44 is optimized for the study of identified single and multiple particle distributions to p T = 0 near mid-rapidity. We measure π +- , K +- , p, bar p, d and bar d, in p + A and A + A collisions at 450 and 20OGeV/u, respectively. Two-particle intensity interferometry results from π + π + , K + K + , and K - K - measurements and single particle distributions are presented
Zhu, Yanan; Ouyang, Qi; Mao, Youdong
2017-07-21
Single-particle cryo-electron microscopy (cryo-EM) has become a mainstream tool for the structural determination of biological macromolecular complexes. However, high-resolution cryo-EM reconstruction often requires hundreds of thousands of single-particle images. Particle extraction from experimental micrographs thus can be laborious and presents a major practical bottleneck in cryo-EM structural determination. Existing computational methods for particle picking often use low-resolution templates for particle matching, making them susceptible to reference-dependent bias. It is critical to develop a highly efficient template-free method for the automatic recognition of particle images from cryo-EM micrographs. We developed a deep learning-based algorithmic framework, DeepEM, for single-particle recognition from noisy cryo-EM micrographs, enabling automated particle picking, selection and verification in an integrated fashion. The kernel of DeepEM is built upon a convolutional neural network (CNN) composed of eight layers, which can be recursively trained to be highly "knowledgeable". Our approach exhibits an improved performance and accuracy when tested on the standard KLH dataset. Application of DeepEM to several challenging experimental cryo-EM datasets demonstrated its ability to avoid the selection of un-wanted particles and non-particles even when true particles contain fewer features. The DeepEM methodology, derived from a deep CNN, allows automated particle extraction from raw cryo-EM micrographs in the absence of a template. It demonstrates an improved performance, objectivity and accuracy. Application of this novel method is expected to free the labor involved in single-particle verification, significantly improving the efficiency of cryo-EM data processing.
NA49 Results on Single Particle and Correlation Measurements in Central PB+PB Collisions
Wang, Fuqiang; Bachler, J.; Bailey, S.J.; Barna, D.; Barnby, L.S.; Bartke, J.; Barton, R.A.; Bialkowska, H.; Billmeier, A.; Blyth, C.O.; Bock, R.; Boimska, B.; Bormann, C.; Brady, F.P.; Brockmann, R.; Brun, R.; Buncic, P.; Caines, H.L.; Carr, L.D.; Cebra, D.A.; Cooper, G.E.; Cramer, J.G.; Cristinziani, M.; Csato, P.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Ferguson, M.I.; Fischer, H.G.; Flierl, D.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Fuchs, M.; Gabler, F.; Gal, J.; Ganz, R.; Gazdzicki, M.; Gladysz, E.; Grebieszkow, J.; Gunther, J.; Harris, J.W.; Hegyi, S.; Henkel, T.; Hill, L.A.; Hummler, H.; Igo, G.; Irmscher, D.; Jacobs, P.; Jones, P.G.; Kadija, K.; Kolesnikov, V.I.; Kowalski, M.; Lasiuk, B.; Levai, P.; Malakhov, A.I.; Margetis, S.; Markert, C.; Melkumov, G.L.; Mock, A.; Molnar, J.; Nelson, John M.; Oldenburg, M.; Odyniec, G.; Palla, G.; Panagiotou, A.D.; Petridis, A.; Piper, A.; Porter, R.J.; Poskanzer, Arthur M.; Prindle, D.J.; Puhlhofer, F.; Rauch, W.; Reid, J.G.; Renfordt, R.; Retyk, W.; Ritter, H.G.; Rohrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sandoval, A.; Sann, H.; Semenov, A.Yu.; Schafer, E.; Schmischke, D.; Schmitz, N.; Schonfelder, S.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Skrzypczak, E.; Snellings, R.; Squier, G.T.A.; Stock, R.; Strobele, H.; Struck, C.; Szentpetery, I.; Sziklai, J.; Toy, M.; Trainor, T.A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Veres, G.; Vesztergombi, G.; Voloshin, S.; Vranic, D.; Weerasundara, D.D.; Wenig, S.; Whitten, C.; Wienold, T.; Wood, L.; Xu, N.; Yates, T.A.; Zimanyi, J.; Zhu, X.Z.; Zybert, R.; Wang, Fuqiang
2000-01-01
Single-particle spectra and two-particle correlation functions measured by the NA49 collaboration in central Pb+Pb collisions at 158 GeV/nucleon are presented. These measurements are used to study the kinetic and chemical freeze-out conditions in heavy ion collisions. We conclude that large baryon stopping, high baryon density and strong transverse radial flow are achieved in central Pb+Pb collisions at the SPS.
Dragonfly : an implementation of the expand–maximize–compress algorithm for single-particle imaging
Ayyer, Kartik; Lan, Ti-Yen; Elser, Veit; Loh, N. Duane
2016-01-01
Single-particle imaging (SPI) with X-ray free-electron lasers has the potential to change fundamentally how biomacromolecules are imaged. The structure would be derived from millions of diffraction patterns, each from a different copy of the macromolecule before it is torn apart by radiation damage. The challenges posed by the resultant data stream are staggering: millions of incomplete, noisy and un-oriented patterns have to be computationally assembled into a three-dimensional intensity map...
Antisymmetrized four-body wave function and coexistence of single particle and cluster structures
International Nuclear Information System (INIS)
Sasakawa, T.
1979-01-01
It is shown that each Yakubovski component of the totally antisymmetric four-body wave function satisfies the same equation as the unantisymmetric wave function. In the antisymmetric total wave function, the wave functions belonging to the same kind of partition are totally antisymmetric among themselves. This leads to the coexistence of cluster models, including the single particle model as a special case of the cluster model, as a sum
Quantum private comparison with d-level single-particle states
International Nuclear Information System (INIS)
Yu, Chao-Hua; Guo, Gong-De; Lin, Song
2013-01-01
In this paper, a quantum private comparison protocol with d-level single-particle states is proposed. In the protocol, a semi-honest third party is introduced to help two participants compare the size relationship of their secrets without revealing them to any other people. It is shown that the protocol is secure in theory. Moreover, the security of the protocol in real circumstance is also discussed. (paper)
Determining Complex Structures using Docking Method with Single Particle Scattering Data
Directory of Open Access Journals (Sweden)
Haiguang Liu
2017-04-01
Full Text Available Protein complexes are critical for many molecular functions. Due to intrinsic flexibility and dynamics of complexes, their structures are more difficult to determine using conventional experimental methods, in contrast to individual subunits. One of the major challenges is the crystallization of protein complexes. Using X-ray free electron lasers (XFELs, it is possible to collect scattering signals from non-crystalline protein complexes, but data interpretation is more difficult because of unknown orientations. Here, we propose a hybrid approach to determine protein complex structures by combining XFEL single particle scattering data with computational docking methods. Using simulations data, we demonstrate that a small set of single particle scattering data collected at random orientations can be used to distinguish the native complex structure from the decoys generated using docking algorithms. The results also indicate that a small set of single particle scattering data is superior to spherically averaged intensity profile in distinguishing complex structures. Given the fact that XFEL experimental data are difficult to acquire and at low abundance, this hybrid approach should find wide applications in data interpretations.
Maity, Srimanta; Das, Amita; Kumar, Sandeep; Tiwari, Sanat Kumar
2018-04-01
The collective response of the plasma medium is well known and has been explored extensively in the context of dusty plasma medium. On the other hand, the individual particle response associated with the collisional character giving rise to the dissipative phenomena has not been explored adequately. In this paper, two-dimensional molecular dynamics simulation of dust particles interacting via Yukawa potential has been considered. It has been shown that disturbances induced in a dust crystal elicit both collective and single particle responses. Generation of a few particles moving at speeds considerably higher than acoustic and/or shock speed (excited by the external disturbance) is observed. This is an indication of a single particle response. Furthermore, as these individual energetic particles propagate, the dust crystal is observed to crack along their path. Initially when the energy is high, these particles generate secondary energetic particles by the collisional scattering process. However, ultimately as these particles slow down they excite a collective response in the dust medium at secondary locations in a region which is undisturbed by the primary external disturbance. The condition when the cracking of the crystal stops and collective excitations get initiated has been identified quantitatively. The trailing collective primary disturbances would thus often encounter a disturbed medium with secondary and tertiary collective perturbations, thereby suffering significant modification in its propagation. It is thus clear that there is an interesting interplay (other than mere dissipation) between the single particle and collective response which governs the dynamics of any disturbance introduced in the medium.
Single-particle resonance levels in {sup 14}O examined by N13+p elastic resonance scattering
Energy Technology Data Exchange (ETDEWEB)
Teranishi, T. [Dept. of Physics, Kyushu Univ., 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)]. E-mail: teranishi@nucl.phys.kyushu-u.ac.jp; Kubono, S. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, H. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); He, J.J. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Saito, A. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Fujikawa, H. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Amadio, G. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Niikura, M.; Shimoura, S. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y. [Dept. of Physics, Kyushu Univ., 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)]|[Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nishimura, S.; Nishimura, M. [RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Moon, J.Y.; Lee, C.S. [Dept. of Physics, Chung-Ang Univ., Seoul 156-756 (Korea, Republic of); Odahara, A. [Nishinippon Inst. of Technology, Kanda, Fukuoka 800-0394 (Japan); Sohler, D. [Inst. of Nuclear Research (ATOMKI), H-4001 Debrecen, P.O. Box 51 (Hungary); Khiem, L.H. [Inst. of Physics and Electronics (IOP), Vietnamese Academy for Science and Technology (VAST), 10 Daotan, Congvi, Badinh, P.O. Box 429-BOHO, Hanoi 10000 (Viet Nam); Li, Z.H.; Lian, G.; Liu, W.P. [China Inst. of Atomic Energy, P.O. Box 275(46), Beijing 102413 (China)
2007-06-28
Single-particle properties of low-lying resonance levels in {sup 14}O have been studied efficiently by utilizing a technique of proton elastic resonance scattering with a {sup 13}N secondary beam and a thick proton target. The excitation functions for the N13+p elastic scattering were measured over a wide energy range of E{sub CM}=0.4-3.3 MeV and fitted with an R-matrix calculation. A clear assignment of J{sup {pi}}=2{sup -} has been made for the level at E{sub x}=6.767(11) MeV in {sup 14}O for the first time. The excitation functions show a signature of a new 0{sup -} level at E{sub x}=5.71(2) MeV with {gamma}=400(100) keV. The excitation energies and widths of the {sup 14}O levels are discussed in conjunction with the spectroscopic structure of A=14 nuclei with T=1.
NNLO QCD corrections to the $B\\to X_s \\gamma$ matrix elements using interpolation in $m_c$
Misiak, M; Misiak, Mikolaj; Steinhauser, Matthias
2007-01-01
One of the most troublesome contributions to the NNLO QCD corrections to B -> X_s gamma originates from three-loop matrix elements of four-quark operators. A part of this contribution that is proportional to the QCD beta-function coefficient beta_0 was found in 2003 as an expansion in m_c/m_b. In the present paper, we evaluate the asymptotic behaviour of the complete contribution for m_c >> m_b/2. The asymptotic form of the beta_0-part matches the small-m_c expansion very well at the threshold m_c = m_b/2. For the remaining part, we perform an interpolation down to the measured value of m_c, assuming that the beta_0-part is a good approximation at m_c=0. Combining our results with other contributions to the NNLO QCD corrections, we find BR(B -> X_s gamma) = (3.15 +_ 0.23) x 10^-4 for E_gamma > 1.6 GeV in the B-meson rest frame. The indicated error has been obtained by adding in quadrature the following uncertainties: non-perturbative (5%), parametric (3%), higher-order perturbative (3%), and the interpolation...
Search for rare processes with a Z+bb signature at the LHC, with the matrix element method
Beluffi, Camille; Lemaitre, Vincent
This thesis presents a detailed study of the final state with the Z boson decaying into two leptons, produced in the CMS detector at the LHC. In order to tag this topology, sophisticated b jet tagging algorithms have been used, and the calibration of one of them, the Jet Probability (JP) tagger is exposed. A study of the tagger degradation at high energy has been done and led to a small gain of performance. This investigation is followed by the search for the associated production of the standard model (SM) Higgs boson with a Z boson and decaying into two b quarks (ZH channel), using the Matrix Element Method (MEM) and two b-taggers: JP and Combined Secondary Vertex (CSV). The MEM is an advanced tool that produces an event-by-event discriminating variable, called weight. To apply it, several sets of transfer function have been produced. The final results give an observed limit on the ZH production cross section with the H → bb branching ratio of 5.46xσSM when using the CSV tagger and 4.89xσSM when using t...
Measurement of the CKM Matrix Element |V sub u sub b | with B -> rho e nu Decays
Wilden, L
2003-01-01
We present a measurement of the branching fraction for the rare decays B -> rho e nu and extract a value for the magnitude of V sub u sub b , one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for five different calculations of form factors used to parametrize the hadronic current in semileptonic decays. Using a sample of 55 million B(bar B) meson pairs recorded with the BABAR detector at the PEP-II e sup + e sup - storage ring, we obtain BETA(B sup 0 -> rho sup - sup 1 e sup + nu) = (3.29 +- 0.42 +- 0.47 +- 0.60) x 10 sup - sup 4 and |V sub u sub b | = (3.64 +- 0.22 +- 0.25 sub - sub 0 sub . sub 5 sub 6 sup + sup 0 sup . sup 3 sup 9) x 10 sup - sup 3 , where the uncertainties are statistical, systematic, and theoretical, respectively.
International Nuclear Information System (INIS)
CDF Collaboration; Freeman, John; Freeman, John
2007-01-01
A measurement of the top quark mass in t(bar t) → l + jets candidate events, obtained from p(bar p) collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t(bar t) production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb -1 data sample, using events with a high-p T lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M meas = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c 2
International Nuclear Information System (INIS)
Jasielska, A.; Wiktor, S.
1977-01-01
The table of two-particle matrix elements calculated according to the formalism of MSDI approximation for the orbits 1fsub(7/2), 2psub(3/2), 2psub(1/2) and 1fsub(5/2) and published previously is now supplemented by inclusion of the 1gsub(9/2) orbit. (author)
International Nuclear Information System (INIS)
Silvestre-Brac, B.; Piepenbring, R.
1978-01-01
Matrix elements of a general Hamiltonian H in a subspace spanned by collective K/sup π/+ deformed phonons are derived with the help of recursion formulas. Various approximations are discussed both in the fermion space and in the boson space. Careful comparisons are made in the framework of a simple solvable model
Chackerian, C., Jr.
1976-01-01
The electric dipole moment function of the ground electronic state of carbon monoxide has been determined by combining numerical solutions of the radial Schrodinger equation with absolute intensity data of vibration-rotation bands. The derived dipole moment function is used to calculate matrix elements of interest to stellar astronomy and of importance in the carbon monoxide laser.
Directory of Open Access Journals (Sweden)
Zhengyan Zhang
2018-03-01
Full Text Available In this paper, we consider the problem of tracking the direction of arrivals (DOA and the direction of departure (DOD of multiple targets for bistatic multiple-input multiple-output (MIMO radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.
Zhang, Zhengyan; Zhang, Jianyun; Zhou, Qingsong; Li, Xiaobo
2018-03-07
In this paper, we consider the problem of tracking the direction of arrivals (DOA) and the direction of departure (DOD) of multiple targets for bistatic multiple-input multiple-output (MIMO) radar. A high-precision tracking algorithm for target angle is proposed. First, the linear relationship between the covariance matrix difference and the angle difference of the adjacent moment was obtained through three approximate relations. Then, the proposed algorithm obtained the relationship between the elements in the covariance matrix difference. On this basis, the performance of the algorithm was improved by averaging the covariance matrix element. Finally, the least square method was used to estimate the DOD and DOA. The algorithm realized the automatic correlation of the angle and provided better performance when compared with the adaptive asymmetric joint diagonalization (AAJD) algorithm. The simulation results demonstrated the effectiveness of the proposed algorithm. The algorithm provides the technical support for the practical application of MIMO radar.
International Nuclear Information System (INIS)
Boucaud, P.; Gimenez, V.; Lin, C.J.D.; Washington Univ., Seattle, WA; Lubicz, V.; Martinelli, G.; Papinutto, M.; Sachrajda, C.T.
2004-12-01
We present the first direct evaluation of ΔI=3/2 K → ππ matrix elements with the aim of determining all the low-energy constants at NLO in the chiral expansion. Our numerical investigation demonstrates that it is indeed possible to determine the K → ππ matrix elements directly for the masses and momenta used in the simulation with good precision. In this range however, we find that the matrix elements do not satisfy the predictions of NLO chiral perturbation theory. For the chiral extrapolation we therefore use a hybrid procedure which combines the observed polynomial behaviour in masses and momenta of our lattice results, with NLO chiral perturbation theory at lower masses. In this way we find stable results for the quenched matrix elements of the electroweak penguin operators ( I=2 left angle ππ vertical stroke O 8 vertical stroke K 0 right angle =(0.68±0.09) GeV 3 and I=2 left angle ππ vertical stroke O 7 vertical stroke K 0 right angle =(0.12±0.02) GeV 3 ), but not for the matrix elements of O 4 (for which there are too many low-energy constants at NLO for a reliable extrapolation). For all three operators we find that the effect of including the NLO corrections is significant (typically about 30%). We present a detailed discussion of the status of the prospects for the reduction of the systematic uncertainties. (orig.)
Scattering matrix approach to non-stationary quantum transport
Moskalets, Michael V
2012-01-01
The aim of this book is to introduce the basic elements of the scattering matrix approach to transport phenomena in dynamical quantum systems of non-interacting electrons. This approach admits a physically clear and transparent description of transport processes in dynamical mesoscopic systems promising basic elements of solid-state devices for quantum information processing. One of the key effects, the quantum pump effect, is considered in detail. In addition, the theory for a recently implemented new dynamical source - injecting electrons with time delay much larger than the electron coherence time - is offered. This theory provides a simple description of quantum circuits with such a single-particle source and shows in an unambiguous way that the tunability inherent to the dynamical systems leads to a number of unexpected but fundamental effects.
Chen, Zhenhua; Chen, Xun; Wu, Wei
2013-04-01
In this series, the n-body reduced density matrix (n-RDM) approach for nonorthogonal orbitals and their applications to ab initio valence bond (VB) methods are presented. As the first paper of this series, Hamiltonian matrix elements between internally contracted VB wave functions are explicitly provided by means of nonorthogonal orbital based RDM approach. To this end, a more generalized Wick's theorem, called enhanced Wick's theorem, is presented both in arithmetical and in graphical forms, by which the deduction of expressions for the matrix elements between internally contracted VB wave functions is dramatically simplified, and the matrix elements are finally expressed in terms of tensor contractions of electronic integrals and n-RDMs of the reference VB self-consistent field wave function. A string-based algorithm is developed for the purpose of evaluating n-RDMs in an efficient way. Using the techniques presented in this paper, one is able to develop new methods and efficient algorithms for nonorthogonal orbital based many-electron theory much easier than by use of the first quantized formulism.
Optimal noise reduction in 3D reconstructions of single particles using a volume-normalized filter
Sindelar, Charles V.; Grigorieff, Nikolaus
2012-01-01
The high noise level found in single-particle electron cryo-microscopy (cryo-EM) image data presents a special challenge for three-dimensional (3D) reconstruction of the imaged molecules. The spectral signal-to-noise ratio (SSNR) and related Fourier shell correlation (FSC) functions are commonly used to assess and mitigate the noise-generated error in the reconstruction. Calculation of the SSNR and FSC usually includes the noise in the solvent region surrounding the particle and therefore does not accurately reflect the signal in the particle density itself. Here we show that the SSNR in a reconstructed 3D particle map is linearly proportional to the fractional volume occupied by the particle. Using this relationship, we devise a novel filter (the “single-particle Wiener filter”) to minimize the error in a reconstructed particle map, if the particle volume is known. Moreover, we show how to approximate this filter even when the volume of the particle is not known, by optimizing the signal within a representative interior region of the particle. We show that the new filter improves on previously proposed error-reduction schemes, including the conventional Wiener filter as well as figure-of-merit weighting, and quantify the relationship between all of these methods by theoretical analysis as well as numeric evaluation of both simulated and experimentally collected data. The single-particle Wiener filter is applicable across a broad range of existing 3D reconstruction techniques, but is particularly well suited to the Fourier inversion method, leading to an efficient and accurate implementation. PMID:22613568
Building the Nanoplasmonics Toolbox Through Shape Modeling and Single Particle Optical Studies
Ringe, Emilie
Interest in nanotechnology is driven by unprecedented properties tailorability, achievable by controlling particle structure and composition. Unlike bulk components, minute changes in size and shape affect the optical and electronic properties of nanoparticles. Characterization of such structure-function relationships and better understanding of structure control mechanisms is crucial to the development of applications such as plasmonic sensors and devices. The objective of the current research is thus twofold: to theoretically predict and understand how shape is controlled by synthesis conditions, and to experimentally unravel, through single particle studies, how shape, composition, size, and surrounding environment affect plasmonic properties in noble metal particles. Quantitative, predictive rules and fundamental knowledge obtained from this research contributes to the "nanoplasmonics toolbox", a library designed to provide scientists and engineers the tools to create and optimize novel nanotechnology applications. In this dissertation, single particle approaches are developed and used to unravel the effects of size, shape, substrate, aggregation state and surrounding environment on the optical response of metallic nanoparticles. Ag and Au nanocubes on different substrates are first presented, followed by the discussion of the concept of plasmon length, a universal parameter to describe plasmon energy for a variety of particle shapes and plasmon modes. Plasmonic sensing (both refractive index sensing and surface-enhanced Raman spectroscopy) and polarization effects are then studied at the single particle level. In the last two Chapters, analytical shape models based on the Wulff construction provide unique modeling tools for alloy and kinetically grown nanoparticles. The former reveals a size-dependence of the shape of small alloy particles (such as those used in catalysis) because of surface segregation, while the latter uniquely models the shape of many
Damping mechanisms of high-lying single-particle states in 91Nb
International Nuclear Information System (INIS)
Molen, H. K. T. van der; Berg, A. M. van den; Harakeh, M. N.; Hunyadi, M.; Kalantar-Nayestanaki, N.; Akimune, H.; Daito, I.; Fujimura, H.; Ihara, F.; Inomata, T.; Ishibashi, K.; Yoshida, H.; Yosoi, M.; Fujita, Y.; Fujiwara, M.; Jaenecke, J.; O'Donnell, T. W.; Laurent, H.; Lhenry, I.; Rodin, V. A.
2007-01-01
Decay by proton emission from high-lying states in 91 Nb, populated in the 90 Zr(α,t) reaction at E α =180 MeV, has been investigated. Decay to the ground state and semidirect decay to the low-lying (2 + ,5 - , and 3 - ) phonon states in 90 Zr were observed. It was found that these phonon states play an important role in the damping process of the single-particle states. An optical-model coupled-channel approach was used successfully to describe the direct and semidirect parts of the decay
Single particle analysis based on Zernike phase contrast transmission electron microscopy.
Danev, Radostin; Nagayama, Kuniaki
2008-02-01
We present the first application of Zernike phase-contrast transmission electron microscopy to single-particle 3D reconstruction of a protein, using GroEL chaperonin as the test specimen. We evaluated the performance of the technique by comparing 3D models derived from Zernike phase contrast imaging, with models from conventional underfocus phase contrast imaging. The same resolution, about 12A, was achieved by both imaging methods. The reconstruction based on Zernike phase contrast data required about 30% fewer particles. The advantages and prospects of each technique are discussed.
Wigglers and single-particle dynamics in the NLC damping rings
International Nuclear Information System (INIS)
Venturini, Marco; Wolski, Andrzej; Dragt, Alex
2003-01-01
Wiggler insertions are expected to occupy a significant portion of the lattice of the Next Linear Collider (NLC) Main Damping Rings (MDR) and have a noticeable impact on the single-particle beam dynamics. Starting from a realistic 3D representation of the magnetic fields we calculate the transfer maps for the wigglers, accounting for linear and nonlinear effects, and we study the beam dynamics with particular attention paid to the Dynamic Aperture(DA). A DA reduction is observed but appears to remain within acceptable limits
Statistical and direct decay of high-lying single-particle excitations
International Nuclear Information System (INIS)
Gales, S.
1993-01-01
Transfer reactions induced by hadronic probes at intermediate energies have revealed a rich spectrum of high-lying excitations embedded in the nuclear continuum. The investigation of their decay properties is believed to be a severe test of their microscopic structure as predicted by microscopic nuclear models. In addition the degree of damping of these simple modes in the nuclear continuum can be obtained by means of the measured particle (n,p) decay branching ratios. The neutron and proton decay studies of high-lying single-particle states in heavy nuclei are presented. (author). 13 refs., 9 figs
Binding energy and single-particle energies in the 16O Region
International Nuclear Information System (INIS)
Fiase, J.O.; Sharma, L.K.
2004-01-01
In this paper we present the binding energy of 16 O together with single-particle energies in the oxygen region by folding together a Hamiltonian in the rest-frame of the nucleus with two-body correlation functions based on the Nijmegen potential. We have found that the binding energies are very sensitive to the core radius rc and that the effects of tensor correlations are non-negligible.Our calculated binding energy, E B = - 127.8 MeV with r c = 0.241 fm compares well with the experimental binding energy, E B = - 127.6 MeV
Directory of Open Access Journals (Sweden)
F. Gaie-Levrel
2012-01-01
Full Text Available A single particle instrument was developed for real-time analysis of organic aerosol. This instrument, named Single Particle Laser Ablation Mass Spectrometry (SPLAM, samples particles using an aerodynamic lens system for which the theoretical performances were calculated. At the outlet of this system, particle detection and sizing are realized by using two continuous diode lasers operating at λ = 403 nm. Polystyrene Latex (PSL, sodium chloride (NaCl and dioctylphtalate (DOP particles were used to characterize and calibrate optical detection of SPLAM. The optical detection limit (DL and detection efficiency (DE were determined using size-selected DOP particles. The DE ranges from 0.1 to 90% for 100 and 350 nm DOP particles respectively and the SPLAM instrument is able to detect and size-resolve particles as small as 110–120 nm. During optical detection, particle scattered light from the two diode lasers, is detected by two photomultipliers and the detected signals are used to trigger UV excimer laser (λ = 248 nm used for one-step laser desorption ionization (LDI of individual aerosol particles. The formed ions are analyzed by a 1 m linear time-of-flight mass spectrometer in order to access to the chemical composition of individual particles. The TOF-MS detection limit for gaseous aromatic compounds was determined to be 0.85 × 10^{−15} kg (∼4 × 10^{3} molecules. DOP particles were also used to test the overall operation of the instrument. The analysis of a secondary organic aerosol, formed in a smog chamber by the ozonolysis of indene, is presented as a first application of the instrument. Single particle mass spectra were obtained with an effective hit rate of 8%. Some of these mass spectra were found to be very different from one particle to another possibly reflecting chemical differences within the investigated indene SOA particles. Our study shows that an exhaustive statistical analysis, over hundreds of particles
DEFF Research Database (Denmark)
Vestergaard, Christian Lyngby
2012-01-01
. The standard method for estimating diusion coecients from single-particle trajectories is based on leastsquares tting to the experimentally measured mean square displacements. This method is highly inecient, since it ignores the high correlations inherent in these. We derive the exact maximum likelihood...... of diusion coecients of hOgg1 repair proteins diusing on stretched uctuating DNA from data previously analyzed using a suboptimal method. Our analysis shows that the proteins have dierent eective diusion coecients and that their diusion coecients are correlated with their residence time on DNA. These results...
Directory of Open Access Journals (Sweden)
David Gómez-Varela
2010-01-01
Full Text Available Voltage-gated ion channels are main players involved in fast synaptic events. However, only slow intracellular mechanisms have so far been described for controlling their localization as real-time visualization of endogenous voltage-gated channels at high temporal and spatial resolution has not been achieved yet. Using a specific extracellular antibody and quantum dots we reveal and characterize lateral mobility as a faster mechanism to dynamically control the number of endogenous ether-a-go-go (Eag1 ion channels inside synapses. We visualize Eag1 entering and leaving synapses by lateral diffusion in the plasma membrane of rat hippocampal neurons. Mathematical analysis of their trajectories revealed how the motion of Eag1 gets restricted when the channels diffuse into the synapse, suggesting molecular interactions between Eag1 and synaptic components. In contrast, Eag1 channels switch to Brownian movement when they exit synapses and diffuse into extrasynaptic membranes. Furthermore, we demonstrate that the mobility of Eag1 channels is specifically regulated inside synapses by actin filaments, microtubules and electrical activity. In summary, using single-particle-tracking techniques with quantum dots nanocrystals, our study shows for the first time the lateral diffusion of an endogenous voltage-gated ion channel in neurons. The location-dependent constraints imposed by cytoskeletal elements together with the regulatory role of electrical activity strongly suggest a pivotal role for the mobility of voltage-gated ion channels in synaptic activity.
Kohno, M.
2018-03-01
Adopting hyperon-nucleon and hyperon-nucleon-nucleon interactions parametrized in chiral effective field theory, single-particle potentials of the Λ and Σ hyperons are evaluated in symmetric nuclear matter and in pure neutron matter within the framework of lowest-order Bruckner theory. The chiral NLO interaction bears strong Λ N -Σ N coupling. Although the Λ potential is repulsive if the coupling is switched off, the Λ N -Σ N correlation brings about the attraction consistent with empirical data. The Σ potential is repulsive, which is also consistent with empirical information. The interesting result is that the Λ potential becomes shallower beyond normal density. This provides the possibility of solving the hyperon puzzle without introducing ad hoc assumptions. The effects of the Λ N N -Λ N N and Λ N N -Σ N N three-baryon forces are considered. These three-baryon forces are first reduced to normal-ordered effective two-baryon interactions in nuclear matter and then incorporated in the G -matrix equation. The repulsion from the Λ N N -Λ N N interaction is of the order of 5 MeV at normal density and becomes larger with increasing density. The effects of the Λ N N -Σ N N coupling compensate the repulsion at normal density. The net effect of the three-baryon interactions on the Λ single-particle potential is repulsive at higher densities.
Li, Jun; Calo, Victor M.
2013-01-01
models although its deviation in the liquid phase is greater. Since the single-particle model reduces the particle number and avoids the time-consuming Ewald summation used to evaluate Coulomb interactions, the proposed model improves the computational
Redundancy-free single-particle equation-of-motion method for nuclei. Pt. 1
International Nuclear Information System (INIS)
Rolnick, P.; Goswami, A.; Oregon Univ., Eugene
1986-01-01
The problem of coupling an odd nucleon to the collective states of an even core is considered in the intermediate-coupling limit. It is now well known that such intermediate-coupling calculations in spherical open-shell nuclei necessitate the inclusion of ground-state correlation or backward coupling which gives rise to an overcomplete basic set of states for the diagonalization of the hamiltonian. In a recent letter, we have derived a technique to free the single-particle equation-of-motion method of redundancy. Here we shall apply this redundancy-free equation-of-motion method to intermediate-coupling calculations in two regions of near-spherical odd-mass nuclei where forward coupling alone has not been successful. It is shown that qualitative effects of backward coupling previously reported are not spurious effects of double counting, although they are significantly modified by the removal of redundancy. We also discuss what further modifications of the theory will be needed in order to treat the dynamical interplay of collective and single-particle modes in nuclei self-consistently on the same footing. (orig.)
Pairing in the BCS and LN approximations using continuum single particle level density
International Nuclear Information System (INIS)
Id Betan, R.M.; Repetto, C.E.
2017-01-01
Understanding the properties of drip line nuclei requires to take into account the correlations with the continuum spectrum of energy of the system. This paper has the purpose to show that the continuum single particle level density is a convenient way to consider the pairing correlation in the continuum. Isospin mean-field and isospin pairing strength are used to find the Bardeen–Cooper–Schrieffer (BCS) and Lipkin–Nogami (LN) approximate solutions of the pairing Hamiltonian. Several physical properties of the whole chain of the Tin isotope, as gap parameter, Fermi level, binding energy, and one- and two-neutron separation energies, were calculated and compared with other methods and with experimental data when they exist. It is shown that the use of the continuum single particle level density is an economical way to include explicitly the correlations with the continuum spectrum of energy in large scale mass calculation. It is also shown that the computed properties are in good agreement with experimental data and with more sophisticated treatment of the pairing interaction.
Wu, Jiayi; Ma, Yong-Bei; Congdon, Charles; Brett, Bevin; Chen, Shuobing; Xu, Yaofang; Ouyang, Qi; Mao, Youdong
2017-01-01
Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM) data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR) in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM). We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC) environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.
Evolution of Single Particle and Collective properties in the Neutron-Rich Mg Isotopes
Reiter, P; Wiens, A; Fitting, J; Lauer, M; Van duppen, P L E; Finke, F
2002-01-01
We propose to study the single particle and collective properties of the neutron-rich Mg isotopes in transfer reactions and Coulomb excitation using REX-ISOLDE and MINIBALL. From the Coulomb excitation measurement precise and largely model independent B( E2 ; 0$^{+}_{g.s.}\\rightarrow$ 2$^{+}_{1}$ ) will be determined for the even-even isotopes. For the odd isotopes the distribution of the E2 strength over a few low-lying states will be measured. The sign of the M1/E2 mixing ratio, extracted from angular distributions, is characteristic of the sign of the deformation, as is the resulting level scheme. The neutron-pickup channel in the transfer reactions will allow for a determination of the single particle properties (spin, parity, spectroscopic factors) of these nuclei. This information will give new insights in changes of nuclear structure in the vicinity of the island of deformation around $^{32}$Mg. A total of 24 shifts of REX beam time is requested.
3D dual-virtual-pinhole assisted single particle tracking microscopy
International Nuclear Information System (INIS)
Ma, Ye; Wang, Yifan; Zhou, Xin; Kuang, Cuifang; Liu, Xu
2014-01-01
We propose a novel approach for high-speed, three-dimensional single particle tracking (SPT), which we refer to as dual-virtual-pinhole assisted single particle tracking microscopy (DVPaSPTM). DVPaSPTM system can obtain axial information of the sample without optical or mechanical depth scanning, so as to offer numbers of advantages including faster imaging, improved efficiency and a great reduction of photobleaching and phototoxicity. In addition, by the use of the dual-virtual-pinhole, the effect that the quantum yield exerts to the fluorescent signal can be eliminated, which makes the measurement independent of the surroundings and increases the accuracy of the result. DVPaSPTM system measures the intensity within different virtual pinholes of which the radii are given by the host computer. Axial information of fluorophores can be measured by the axial response curve through the ratio of intensity signals. We demonstrated the feasibility of the proposed method by a series of experiments. Results showed that the standard deviation of the axial measurement was 19.2 nm over a 2.5 μm range with 30 ms temporal resolution. (papers)
Directory of Open Access Journals (Sweden)
Jiayi Wu
Full Text Available Structural heterogeneity in single-particle cryo-electron microscopy (cryo-EM data represents a major challenge for high-resolution structure determination. Unsupervised classification may serve as the first step in the assessment of structural heterogeneity. However, traditional algorithms for unsupervised classification, such as K-means clustering and maximum likelihood optimization, may classify images into wrong classes with decreasing signal-to-noise-ratio (SNR in the image data, yet demand increased computational costs. Overcoming these limitations requires further development of clustering algorithms for high-performance cryo-EM data processing. Here we introduce an unsupervised single-particle clustering algorithm derived from a statistical manifold learning framework called generative topographic mapping (GTM. We show that unsupervised GTM clustering improves classification accuracy by about 40% in the absence of input references for data with lower SNRs. Applications to several experimental datasets suggest that our algorithm can detect subtle structural differences among classes via a hierarchical clustering strategy. After code optimization over a high-performance computing (HPC environment, our software implementation was able to generate thousands of reference-free class averages within hours in a massively parallel fashion, which allows a significant improvement on ab initio 3D reconstruction and assists in the computational purification of homogeneous datasets for high-resolution visualization.
Single particle train ordering in microchannel based on inertial and vortex effects
Fan, Liang-Liang; Yan, Qing; Zhe, Jiang; Zhao, Liang
2018-06-01
A new microfluidic device for microparticle focusing and ordering in a single particle train is reported. The particle focusing and ordering are based on inertial and vortex effects in a microchannel with a series of suddenly contracted and widely expanded structures on one side. In the suddenly contracted regions, particles located near the contracted structures are subjected to a strong wall-effect lift force and momentum-change-induced inertial force due to the highly curved trajectory, migrating to the straight wall. A horizontal vortex is generated downstream of the contracted structure, which prevents the particle from getting close to the wall. In the widely expanded regions, the streamline is curved and no vortex is generated. The shear-gradient lift force and the momentum-change-induced inertial force are dominant for particle lateral migration, driving particles towards the wall of the expanded structures. Eventually, particles are focused and ordered in a single particle train by the combination effects of the inertial forces and the vortex. In comparison with other single-stream particle focusing methods, this device requires no sheath flow, is easy for fabrication and operation, and can work over a wide range of Reynolds numbers from 19.1–142.9. The highly ordered particle chain could be potentially utilized in a variety of lab-chip applications, including micro-flow cytometer, imaging and droplet-based cell entrapment.
Competition between collective and single particle excitations in nuclear structure description
International Nuclear Information System (INIS)
Petrovici, A.N.
1983-01-01
The microscopic description of the quadrupole collective dynamics in even krypton isotopes is presented. A microscopic calculation of Bohr's collective Hamiltonian is used to describe the collective motion in 76 Kr. A single-particle basis calculated in a deformed Woods-Saxon potential leads to the potential energy surface obtained by the Strutinsky renormalization procedure, and to the inertial functions determined in the cranking model approximation. The collective Schroedinger equation is solved numerically to analyse the low-energy, even parity states in 76 Kr. A good agreement between experiment and theory is obtained without specifically adjusting any parameter in the model for this nucleus. Some results regarding statical and dynamical characteristics of sup(74,78,80)Kr isotopes are also presented. The asymmetric rotor model with admixture of two quasiparticles is used to describe the sup(66,68,70)Ge and the sup(64,66)Zn isotopes. The interplay of collective and single particle motions is further investigated by magnetic moment measurements using the method of integral angular correlations perturbed by recoil into gas. The results involve g-factor measurements for 166 Ho, 68 Ge, 64 Zn, 66 Zn and 68 Ga nuclei. Finally, a discussion of further possible improvements and more general developments of the problems under investigation is given. (author)
International Nuclear Information System (INIS)
Colo, G.; SAgawa, H.; Bortignon, P. F.
2009-01-01
To study the structure of atomic nuclei, the ab-initio methods can nowadays be applied only for mass number A smaller than ∼ 10-15. For heavier systems, the self-consistent mean-field (SCMF) approach is probably the most microscopic approach which can be systematically applied to stable and exotic nuclei. In practice, the SCMF is mostly based on parametrizations of an effective interaction. However, the are groups who are intensively working on the development of a general density functional (DF) which is not necessarily extracted from an Hamiltonian. The basic question is to what extent this allows improving on the existing functionals. In this contribution we analyze the performance of existing functionals as far as the reproduction of single-particle states is concerned. We start by analyzing the effect of the tensor terms, on which the attention of several groups have recently focused. Then we discuss the impact of the particle-vibration coupling (PVC). Although the basic idea of this approach dates back to long time ago, we present here for the first time calculations which are entirely based on microscopic interactions without dropping any term or introducing ad hoc parameters. We show results both for well-known, benchmark nuclei like 4 0C a and 2 08P b as well as unstable nuclei like 1 32S n. Both single-particle energies and spectroscopic factors are discussed.(author)
Sultana, Camille M; Al-Mashat, Hashim; Prather, Kimberly A
2017-10-03
Ocean-derived microbes in sea spray aersosol (SSA) have the potential to influence climate and weather by acting as ice nucleating particles in clouds. Single particle mass spectrometers (SPMSs), which generate in situ single particle composition data, are excellent tools for characterizing aerosols under changing environmental conditions as they can provide high temporal resolution and require no sample preparation. While SPMSs have proven capable of detecting microbes, these instruments have never been utilized to definitively identify aerosolized microbes in ambient sea spray aersosol. In this study, an aerosol time-of-flight mass spectrometer was used to analyze laboratory generated SSA produced from natural seawater in a marine aerosol reference tank. We present the first description of a population of biological SSA mass spectra (BioSS), which closely match the ion signatures observed in previous terrestrial microbe studies. The fraction of BioSS dramatically increased in the largest supermicron particles, consistent with field and laboratory measurements of microbes ejected by bubble bursting, further supporting the assignment of BioSS mass spectra as microbes. Finally, as supported by analysis of inorganic ion signals, we propose that dry BioSS particles have heterogeneous structures, with microbes adhered to sodium chloride nodules surrounded by magnesium-enriched coatings. Consistent with this structure, chlorine-containing ion markers were ubiquitous in BioSS spectra and identified as possible tracers for distinguishing recently aerosolized marine from terrestrial microbes.
International Nuclear Information System (INIS)
Lerma H, S.
2010-01-01
The structure of the exact wave function of the isovectorial pairing Hamiltonian with nondegenerate single-particle levels is discussed. The way that the single-particle splittings break the quartet condensate solution found for N=Z nuclei in a single degenerate level is established. After a brief review of the exact solution, the structure of the wave function is analyzed and some particular cases are considered where a clear interpretation of the wave function emerges. An expression for the exact wave function in terms of the isospin triplet of pair creators is given. The ground-state wave function is analyzed as a function of pairing strength, for a system of four protons and four neutrons. For small and large values of the pairing strength a dominance of two-pair (quartets) scalar couplings is found, whereas for intermediate values enhancements of the nonscalar couplings are obtained. A correlation of these enhancements with the creation of Cooper-like pairs is observed.
International Nuclear Information System (INIS)
Garron, Nicolas; Hudspith, Renwick J.; Lytle, Andrew T.
2016-01-01
We compute the hadronic matrix elements of the four-quark operators relevant for K 0 −K̄ 0 mixing beyond the Standard Model. Our results are from lattice QCD simulations with n f =2+1 flavours of domain-wall fermion, which exhibit continuum-like chiral-flavour symmetry. The simulations are performed at two different values of the lattice spacing (a∼0.08 and a∼0.11 fm) and with lightest unitary pion mass ∼300 MeV. For the first time, the full set of relevant four-quark operators is renormalised non-perturbatively through RI-SMOM schemes; a detailed description of the renormalisation procedure is presented in a companion paper. We argue that the intermediate renormalisation scheme is responsible for the discrepancies found by different collaborations. We also study different normalisations and determine the matrix elements of the relevant four-quark operators with a precision of ∼5% or better.
Measurement of the matrix elements for the decays η'→η π+π- and η'→η π0π0
Ablikim, M.; Achasov, M. N.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Bai, Y.; Bakina, O.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Berger, N.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chai, J.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X. R.; Chen, Y. B.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dorjkhaidav, O.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fegan, S.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, Y.; Gao, Y. G.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, S.; Gu, Y. T.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y. P.; Haddadi, Z.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, X. Q.; Heinsius, F. H.; Held, T.; Heng, Y. K.; Holtmann, T.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Z. L.; Hussain, T.; Ikegami Andersson, W.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jin, Y.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Khan, T.; Khoukaz, A.; Kiese, P.; Kliemt, R.; Koch, L.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kuemmel, M.; Kuhlmann, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Lavezzi, L.; Leithoff, H.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, K. J.; Li, Lei; Li, P. L.; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, Ke; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Long, Y. F.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Magnoni, A. S.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Meng, Z. X.; Messchendorp, J. G.; Mezzadri, G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Morello, G.; Muchnoi, N. Yu.; Muramatsu, H.; Mustafa, A.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Papenbrock, M.; Patteri, P.; Pelizaeus, M.; Pellegrino, J.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, N.; Qin, X.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Richter, M.; Ripka, M.; Rolo, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schnier, C.; Schoenning, K.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, J. J.; Song, W. M.; Song, X. Y.; Sosio, S.; Sowa, C.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, L.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. K.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, G. Y.; Tang, X.; Tapan, I.; Tiemens, M.; Tsednee, B. T.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, Dan; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Y. J.; Xiao, Z. J.; Xie, Y. G.; Xie, Y. H.; Xiong, X. A.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. H.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; You, Z. Y.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhou, Y. X.; Zhu, J.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Besiii Collaboration
2018-01-01
Based on a sample of 1.31 ×109 J /ψ events collected with the BESIII detector, the matrix elements for the decays η'→η π+π- and η'→η π0π0 are determined using 351,016 η'→(η →γ γ )π+π- and 56,249 η'→(η →γ γ )π0π0 events with background levels less than 1%. Two commonly used representations are used to describe the Dalitz plot density. We find that an assumption of a linear amplitude does not describe the data well. A small deviation of the obtained matrix elements between η'→η π+π- and η'→η π0π0 is probably caused by the mass difference between charged and neutral pions or radiative corrections. No cusp structure in η'→η π0π0 is observed.
International Nuclear Information System (INIS)
Ablinger, J.; Bluemlein, J.; Klein, S.; Schneider, C.; Wissbrock, F.
2011-01-01
The contributions ∝n f to the O(α s 3 ) massive operator matrix elements describing the heavy flavor Wilson coefficients in the limit Q 2 >>m 2 are computed for the structure function F 2 (x,Q 2 ) and transversity for general values of the Mellin variable N. Here, for two matrix elements, A qq,Q PS (N) and A qg,Q (N), the complete result is obtained. A first independent computation of the contributions to the 3-loop anomalous dimensions γ qg (N), γ qq PS (N), and γ qq NS,(TR) (N) is given. In the computation advanced summation technologies for nested sums over products of hypergeometric terms with harmonic sums have been used. For intermediary results generalized harmonic sums occur, while the final results can be expressed by nested harmonic sums only.
International Nuclear Information System (INIS)
Huang Zanjun; Yang Bin; Cui Hua; Zhang Jishan
2003-01-01
A new idea to fabricate aluminum matrix composites strengthened by combined in-situ particle strengthening and in-situ alloying has been proposed. Following the concept of in-situ alloying and in-situ particle strengthening, aluminum matrix composites reinforced by Cu and α-Al 2 O 3 particulate (material I) and the same matrix reinforced by Cu, Si alloying elements and α-Al 2 O 3 particulate (material II) have been obtained. SEM observation, EDS and XRD analysis show that the alloy elements Cu and Si exist in the two materials, respectively. In-situ Al 2 O 3 particulates are generally spherical and their mean size is less than 0.5 μm. TEM observation shows that the in-situ α-Al 2 O 3 particulates have a good cohesion with the matrix. The reaction mechanism of the Al 2 O 3 particulate obtained by this method was studied. Thermodynamic considerations are given to the in-situ reactions and the distribution characteristic of in-situ the α-Al 2 O 3 particulate in the process of solidification is also discussed
International Nuclear Information System (INIS)
Bonatsos, D.; Lo Liduce, N.; Raychev, P.; Roussev, R.; Terziev, P.
1996-01-01
Quantum algebras (also called quantum groups) are nonlinear generalization of the usual Lie algebras, to which the reduce in the limiting case when the deformed parameters are set equal to unity. From mathematical point of view they have the structure of Holf algebras. The interest for applications of quantum algebras in physics was triggered in 1989 by the introduction of the q-deformed harmonic oscillator. In this connection the quantum algebra su q (2) has been used for description of superdeformed bands of even-even nuclei and rotational nuclear and molecular spectra. The construction of chains of subalgebras of a given q-algebra is a non trivial problem, since the existence of a chain of subalgebras of the corresponding Lie algebra does not guarantee the existence of the q-analogue of this chain. In particular, the so q (3) subalgebra of u q (3) has attracted much attention, since its classical analogue is a basic ingredient of several nuclear models, as the Elliot model and the su(3) limit of the Interacting Boson Model (IBM), the Fermion Dynamical Symmetry Model (FDSM), the Interacting Vector Boson Model (IVBM), the nuclear vibron model for clustering, as well as of the su(3) limit of the vibron model for molecules. In the present report we compute the reduced matrix elements of a special second-rank tensor operator (quadrupole operator) in the so q (3) subgroup of u q (3) basis (for the most symmetric u q (3)-representations) and investigate some of their properties. Also we construct a simplified boson realization of the so q (3) subalgebra of u q (3) and the corresponding so q (3) basis states. It should be noted that the obtained results are valid only for real values of the deformation parameter q. On the other hand the comparison of the experimental data with the predictions of a number of physical models, based on the q deformed su q (2) algebra, shows that one can achieve a good agreement between theory and experiment only if q is a pure phase (q
International Nuclear Information System (INIS)
Haefner, Petra
2008-01-01
The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with the W boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t anti t→W ± W -+ b anti b→q anti qlνb anti b is the ''golden channel'' for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb -1 of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m t =(169.2±3.5(stat.)±1.0(syst.)) GeV. The simultaneous measurement of a scaling factor for the jet energy
Energy Technology Data Exchange (ETDEWEB)
Haefner, Petra
2008-07-31
The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with the W boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t anti t{yields}W{sup {+-}}W{sup -+}b anti b{yields}q anti ql{nu}b anti b is the ''golden channel'' for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb{sup -1} of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m{sub t}=(169.2{+-}3.5(stat.){+-}1.0(syst.)) GeV. The
Lin Yan Chang; Lai Wan Chang; Zhou Si Chun
2002-01-01
Dot matrix LCD based on T6963C is a low power supply module. It needs no complex interface circuits connecting with MCU. Application in text and graphics is easy. Application of this LCD in multi-element portable XRF spectrometry is show. How to use it in Chinese, pull-down menu, spectrum and how to design the interface circuits with embedded computer are shown as well
International Nuclear Information System (INIS)
Yannouleas, C.; Pacheco, J.M.
1989-01-01
A collection of procedures able to perform algebraic manipulations for the orthonormalization and for the calculation of matrix elements between the states associated with the U(5)containsO(5)containsO(3) chain of groups is presented. These procedures combine both the exact- and the bigfloat-arithmetic modes and thus return arbitrarily accurate results; this is particulary relevant to the Gram-Schmidt orthonormalization, where strong cancellations usually pose serious problems in all floating-point implementations. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Freeman, John [Univ. of California, Berkeley, CA (United States)
2007-01-01
A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t$\\bar{t}$ production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb^{-1} data sample, using events with a high-p_{T} lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M_{meas} = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c^{2}.
International Nuclear Information System (INIS)
Soldatov, A.; Seke, J.; Adam, G.; Polak, M.
2008-01-01
Full text: A closed analytic form for relativistic transition matrix elements between bound-bound, bound-unbound and unbound-unbound relativistic eigenstates of hydrogenic atoms by using the plane-wave expansion for the electromagnetic-field vector potential was derived in a form convenient for large-scale numerical calculations in QED. By applying the obtained formulae, these transition matrix elements can be evaluated analytically and numerically. These exact matrix elements, which to our knowledge have not been calculated as yet, are of great importance in the analysis of various atom-field interaction processes where retardation effects cannot be ignored. The ultimate goal of the ongoing research is to develop a general universal calculation technique for Seke's approximation and renormalization method in QED, for which the usage of the plane vector expansion for the vector potential is a preferable choice. However, our primary interest lies in the Lamb-shift calculation. Our nearest objective is to carry out the plain-style relativistic calculations of the Lamb shift of the energy levels of hydrogen-like atoms and ions from first principles in the second and higher perturbative orders, using the corresponding convenient as well as novel expressions for the magnitude in question as they stand, i.e. without any additional approximations. Due to that there is no way to achieve all the above-declared goals without recourse to large-scale laborious and time-consuming high-precision numerical calculations, having the transition matrix elements of all possible types in an analytic, convenient for their efficient numerical evaluation form, would be highly advantageous and even unavoidable, especially for calculations of various QED effects in higher perturbative orders be it, equally, in traditional or novel approach. (author)
Energy Technology Data Exchange (ETDEWEB)
Kroeninger, Kevin Alexander; /Bonn U.
2004-04-01
Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.
Energy Technology Data Exchange (ETDEWEB)
Ablinger, J. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Blümlein, J.; De Freitas, A. [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Hasselhuhn, A. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Manteuffel, A. von [PRISMA Cluster of Excellence and Institute of Physics, J. Gutenberg University, D-55099 Mainz (Germany); Round, M. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Schneider, C. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Wißbrock, F. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2014-05-15
We calculate the massive unpolarized operator matrix element A{sub gq}{sup (3)}(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α{sub s}{sup 3}). A first independent recalculation is performed for the contributions ∝N{sub F} of the 3-loop anomalous dimension γ{sub gq}{sup (2)}(N)
Energy Technology Data Exchange (ETDEWEB)
Behring, A.; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen Synchrotron, DESY, Zeuthen (Germany); Bierenbaum, I. [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany); Klein, S. [RWTH Aachen University, Institut fuer Theoretische Teilchenphysik und Kosmologie, Aachen (Germany); Wissbrock, F. [Deutsches Elektronen Synchrotron, DESY, Zeuthen (Germany); Johannes Kepler University, Research Institute for Symbolic Computation (RISC), Linz (Austria); IHES, Bures-sur-Yvette (France)
2014-09-15
We calculate the logarithmic contributions to the massive Wilson coefficients for deep-inelastic scattering in the asymptotic region Q{sup 2} >> m{sup 2} to 3-loop order in the fixed flavor number scheme and present the corresponding expressions for the massive operator matrix elements needed in the variable flavor number scheme. Explicit expressions are given in Mellin N-space. (orig.)
Rienks, E. D. L.; ńrrälä, M.; Lindroos, M.; Roth, F.; Tabis, W.; Yu, G.; Greven, M.; Fink, J.
2014-09-01
We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd2-xCexCuO4, x =0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.
Rienks, E D L; Ärrälä, M; Lindroos, M; Roth, F; Tabis, W; Yu, G; Greven, M; Fink, J
2014-09-26
We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd(2-x)Ce(x)CuO₄, x=0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.
Energy Technology Data Exchange (ETDEWEB)
Schade, L.; Schwarz, U.T. [Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79108 Freiburg (Germany); Fraunhofer Institute for Applied Solid State Physics (IAF), Tullastrasse 72, 79108 Freiburg (Germany); Wernicke, T. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Weyers, M. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany); Kneissl, M. [Institute of Solid State Physics, Technical University, Hardenbergstrasse 36, 10623 Berlin (Germany); Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Strasse 4, 12489 Berlin (Germany)
2011-03-15
Partial or full linear polarization is characteristic for the spontaneous emission of light from semipolar and nonpolar InGaN quantum wells. This property is an implication of the crystalline anisotropy as a basic property of the wurtzite structure. The influence of this anisotropy on the band structure and the transition matrix elements was calculated by a k.p-method for arbitrary quantum well orientations with respect to the c-axis; results are shown here in detail. Optical polarization is a direct consequence of a broken symmetry, mainly affecting the transition matrix elements from the conduction to the valence bands. Furthermore, the strain of the InGaN quantum well strongly depends on the crystal orientation of the substrate, resulting in a valence band mixing. The composition of the eigenfunctions has emerged to be most important for the polarization dependence of strained semipolar and nonpolar InGaN QW. The matrix elements, in combination with the thermal occupation of the bands, determine the polarization of the spontaneously emitted light. Our photoluminescence measurements of nonpolar QW match well with this model. However, in contrast to calculations with standard band parameters, the two topmost subbands show a larger separation in the emitted energy. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
International Nuclear Information System (INIS)
Tanuma, T.; Oneda, S.; Terasaki, K.
1984-01-01
A new approach to nonleptonic weak interactions is presented. It is argued that the presence and violation of the Vertical BarΔIVertical Bar = 1/2 rule as well as those of the quark-line selection rules can be explained in a unified way, along with other fundamental physical quantities [such as the value of g/sub A/(0) and the smallness of the isoscalar nucleon magnetic moments], in terms of a single dynamical asymptotic ansatz imposed at the level of observable hadrons. The ansatz prescribes a way in which asymptotic flavor SU(N) symmetry is secured levelwise for a certain class of chiral algebras in the standard QCD model. It yields severe asymptotic constraints upon the two-particle hadronic matrix elements of nonleptonic weak Hamiltonians as well as QCD currents and their charges. It produces for weak matrix elements the asymptotic Vertical BarΔIVertical Bar = 1/2 rule and its charm counterpart for the ground-state hadrons, while for strong matrix elements quark-line-like approximate selection rules. However, for the less important weak two-particle vertices involving higher excited states, the Vertical BarΔIVertical Bar = 1/2 rule and its charm counterpart are in general violated, providing us with an explicit source of the violation of these selection rules in physical processes
DEFF Research Database (Denmark)
Vidmar, Janja; Buerki-Thurnherr, Tina; Löschner, Katrin
2018-01-01
and their size are required for studying NP accumulation in placental tissue. In the present study, we applied and compared two sample preparation techniques, alkaline and enzymatic treatment, followed by single particle ICP-MS (spICP-MS) analysis, for characterizing AgNPs spiked to human placental tissue. Both...... sample preparation approaches are currently used for AgNPs in biological tissues but have not been directly compared yet. We showed that the method using enzymatic tissue treatment followed by spICP-MS is efficient for determination of mass and number concentration and size distribution of AgNPs in human...... placental tissues. Properties of the AgNPs were preserved during enzymatic digestion and comparable with the primary particles. The matrix effect on the determination of Ag sensitivity and transport efficiency in spICP-MS analysis was systematically evaluated as well. The method was applied to human...
International Nuclear Information System (INIS)
Kirsch, Matthias
2009-01-01
At particle accelerators the Standard Model has been tested and will be tested further to a great precision. The data analyzed in this thesis have been collected at the world's highest energetic-collider, the Tevatron, located at the Fermi National Accelerator Laboratory (FNAL) in the vicinity of Chicago, IL, USA. There, protons and antiprotons are collided at a center-of-mass energy of √s = 1.96 TeV. The discovery of the top quark was one of the remarkable results not only for the CDF and D0 experiments at the Tevatron collider, but also for the Standard Model, which had predicted the existence of the top quark because of symmetry arguments long before already. Still, the Tevatron is the only facility able to produce top quarks. The predominant production mechanism of top quarks is the production of a top-antitop quark pair via the strong force. However, the Standard Model also allows the production of single top quarks via the electroweak interaction. This process features the unique opportunity to measure the |V tb | matrix element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix directly, without assuming unitarity of the matrix or assuming that the number of quark generations is three. Hence, the measurement of the cross section of electroweak top quark production is more than the technical challenge to extract a physics process that only occurs one out of ten billion collisions. It is also an important test of the V-A structure of the electroweak interaction and a potential window to physics beyond the Standard Model in the case where the measurement of |V tb | would result in a value significantly different from 1, the value predicted by the Standard Model. At the Tevatron two production processes contribute significantly to the production of single top quarks: the production via the t-channel, also called W-gluon fusion, and the production via the s-channel, known as well as W* process. This analysis searches for the combined s+t channel production cross
Energy Technology Data Exchange (ETDEWEB)
Kirsch, Matthias [RWTH Aachen Univ. (Germany)
2009-06-29
At particle accelerators the Standard Model has been tested and will be tested further to a great precision. The data analyzed in this thesis have been collected at the world's highest energetic-collider, the Tevatron, located at the Fermi National Accelerator Laboratory (FNAL) in the vicinity of Chicago, IL, USA. There, protons and antiprotons are collided at a center-of-mass energy of {radical}s = 1.96 TeV. The discovery of the top quark was one of the remarkable results not only for the CDF and D0 experiments at the Tevatron collider, but also for the Standard Model, which had predicted the existence of the top quark because of symmetry arguments long before already. Still, the Tevatron is the only facility able to produce top quarks. The predominant production mechanism of top quarks is the production of a top-antitop quark pair via the strong force. However, the Standard Model also allows the production of single top quarks via the electroweak interaction. This process features the unique opportunity to measure the |V_{tb}| matrix element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix directly, without assuming unitarity of the matrix or assuming that the number of quark generations is three. Hence, the measurement of the cross section of electroweak top quark production is more than the technical challenge to extract a physics process that only occurs one out of ten billion collisions. It is also an important test of the V-A structure of the electroweak interaction and a potential window to physics beyond the Standard Model in the case where the measurement of |V{sub tb}| would result in a value significantly different from 1, the value predicted by the Standard Model. At the Tevatron two production processes contribute significantly to the production of single top quarks: the production via the t-channel, also called W-gluon fusion, and the production via the s-channel, known as well as W* process. This analysis searches for the combined s
Energy Technology Data Exchange (ETDEWEB)
Paredes, Eduardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Maestre, Salvador E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, Jose L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain)]. E-mail: jose.todoli@ua.es
2006-03-15
A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l{sup -1} in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l{sup -1} for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min.
International Nuclear Information System (INIS)
Paredes, Eduardo; Maestre, Salvador E.; Todoli, Jose L.
2006-01-01
A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l -1 in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l -1 for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min
Chaos and nonlinear dynamics of single-particle orbits in a magnetotaillike magnetic field
Chen, J.; Palmadesso, P. J.
1986-01-01
The properties of charged-particle motion in Hamiltonian dynamics are studied in a magnetotaillike magnetic field configuration. It is shown by numerical integration of the equation of motion that the system is generally nonintegrable and that the particle motion can be classified into three distinct types of orbits: bounded integrable orbits, unbounded stochastic orbits, and unbounded transient orbits. It is also shown that different regions of the phase space exhibit qualitatively different responses to external influences. The concept of 'differential memory' in single-particle distributions is proposed. Physical implications for the dynamical properties of the magnetotail plasmas and the possible generation of non-Maxwellian features in the distribution functions are discussed.
Proton resonance elastic scattering of $^{30}$Mg for single particle structure of $^{31}$Mg
The single particle structure of $^{31}$Mg, which is located in the so-called “island of inversion”, will be studied through measuring Isobaric Analog Resonances (IARs) of bound states of $^{31}$Mg. They are located in the high excitation energy of $^{31}$Al. We are going to determine the spectroscopic factors and angular momenta of the parent states by measuring the excitation function of the proton resonance elastic scattering around 0 degrees in the laboratory frame with around 3 MeV/nucleon $^{30}$Mg beam. The present study will reveal the shell evolution around $^{32}$Mg. In addition, the spectroscopic factor of the (7/2)$^{−}$ state which was not yet determined experimentally, may allow one to study the shape coexistence in this nucleus.
Self-consistent neutral point current and fields from single particle dynamics
International Nuclear Information System (INIS)
Martin, R.F. Jr.
1988-01-01
In order to begin to build a global model of the magnetotail-auroral region interaction, it is of interest to understand the role of neutral points as potential centers of particle energization in the tail. In this paper, the single particle current is calculated near a magnetic neutral point with magnetotail properties. This is balanced with the Ampere's law current producing the magnetic field to obtain the self-consistent electric field for the problem. Also calculated is the current-electric field relationship and, in the regime where this relation is linear, an effective conductivity. Results for these macroscopic quantities are surprisingly similar to the values calculated for a constant normal field current sheet geometry. Application to magnetotail modeling is discussed. 11 references
Role of bumpy fields on single particle orbit in near quasihelically symmetric stellarators
International Nuclear Information System (INIS)
Seol, JaeChun; Hegna, C.C.
2004-01-01
The role of symmetry breaking on single particle orbits in near helically symmetric stellarators is investigated. In particular, the effect of a symmetry-breaking bumpy term is included in the analysis of trapped particle orbits. It is found that all trapped particle drift orbits are determined by surfaces on which vertical bar B vertical bar min is constant. Trapped particle orbits reside on these surfaces regardless of pitch angle and are determined solely by the initial position and the shape of the vertical bar B vertical bar min contour. Since vertical bar B vertical bar min contours do not depend on the direction of the banana center motion, superbanana orbits do not appear
EMHP: an accurate automated hole masking algorithm for single-particle cryo-EM image processing.
Berndsen, Zachary; Bowman, Charles; Jang, Haerin; Ward, Andrew B
2017-12-01
The Electron Microscopy Hole Punch (EMHP) is a streamlined suite of tools for quick assessment, sorting and hole masking of electron micrographs. With recent advances in single-particle electron cryo-microscopy (cryo-EM) data processing allowing for the rapid determination of protein structures using a smaller computational footprint, we saw the need for a fast and simple tool for data pre-processing that could run independent of existing high-performance computing (HPC) infrastructures. EMHP provides a data preprocessing platform in a small package that requires minimal python dependencies to function. https://www.bitbucket.org/chazbot/emhp Apache 2.0 License. bowman@scripps.edu. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.
International Nuclear Information System (INIS)
Garberoglio, Giovanni
2010-01-01
We present the results of computer simulations of methanol confined in carbon nanotubes. Different levels of confinement were identified as a function of the nanotube radius and characterized using a pair-distribution function adapted to the cylindrical geometry of these systems. Dynamical properties of methanol were also analysed as a function of the nanotube size, both at the level of single-particle and collective properties. We found that confinement in narrow carbon nanotubes strongly affects the dynamical properties of methanol with respect to the bulk phase, due to the strong interaction with the carbon nanotube. In the other cases, confined methanol shows properties quite similar to those of the bulk phase. These phenomena are related to the peculiar hydrogen bonded network of methanol and are compared to the behaviour of water confined in similar conditions. The effect of nanotube flexibility on the dynamical properties of confined methanol is also discussed.
Zhan, Kangshu
Monitoring chiral optical signals of biomolecules as their conformation changes is an important means to study their structures, properties, and functions. Most measurements, however, are ensemble measurements because chiral optical signals from a single biomolecule is often too weak to be detected. In this dissertation, I present my early attempts to study conformational changes of adsorbed proteins by taking advantage of the enhanced electromagnetic (EM) field around a well-designed plasmonic nanofeature. In particular, I discuss the detection of protein adsorption and denaturation on metallic nanoparticles using single particle scattering and CD spectroscopic imaging. Particles of two distinctively different sizes were compared and two different sample protein molecules were studied. A combination of experimental and computational tools was used to simulate and interpret the collected scattering and CD results. The first chapter provides a brief overview of the state-of-art research in CD spectroscopic studies at the single particle level. Three different means to make particles capable of chiral detection are discussed. Various applications beyond single particle imaging are presented to showcase the potential of the described research project, beyond our immediate goals. The second chapter describes my initial characterization of large, metallic, anisotropic nanorods and the establishment of experimental procedures used later for spectrum reconstruction, data visualization and analysis. The physical shape and structure of the particles were imaged by scanning electron microscopy (SEM), the chemical composition by energy dispersive X-ray Spectroscopy (EDS), and the optical properties by darkfield microscopy. An experimental protocol was developed to connect information collected from separate techniques for the same particle, with the aims of discovering any possible structural-property correlation. The reproducibility of the single particle imaging method was
Single-particle states in ^112Cd probed with the ^111Cd(d,p) reaction
Garrett, P. E.; Jamieson, D.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Wong, J.; Ball, G. C.; Hertenberger, R.; Wirth, H.-F.; Kr"Ucken, R.; Faestermann, T.
2009-10-01
As part of a program of detailed spectroscopy of the Cd isotopes, the single-particle neutron states in ^112Cd have been probed with the ^111Cd(d,p) reaction. Beams of polarized 22 MeV deuterons, obtained from the LMU/TUM Tandem Accelerator, bombarded a target of ^111Cd. The protons from the reaction, corresponding to excitation energies up to 3 MeV in ^112Cd, were momentum analyzed with the Q3D spectrograph. Cross sections and analyzing powers were fit to results of DWBA calculations, and spectroscopic factors were determined. The results from the experiment, and implications for the structure of ^112Cd, will be presented.
Decay modes of high-lying single-particle states in [sup 209]Pb
Energy Technology Data Exchange (ETDEWEB)
Beaumel, D.; Fortier, S.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Vernotte, J.; Bordewijk, J.A.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M. (Institut de Physique Nucleaire, Institut National de Physique Nucleaire et de Physique des Particules Centre National de la Recherche Scientifique, 91406 Orsay Cedex (France) Kernfysisch Versneller Instituut, 9747AA Groningen (Netherlands) National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States) Departamento de Fisica, Fac. Cs. Exactas, Universidad Nacional de La Plata, CC No. 67, 1900 La Plata (Argentina))
1994-05-01
The neutron decay of high-lying single-particle states in [sup 209]Pb excited by means of the ([alpha],[sup 3]He) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in [sup 208]Pb. The structure located between 8.5 and 12 MeV excitation energy in [sup 209]Pb displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3[sup [minus
Decay modes of high-lying single-particle states in 209Pb
International Nuclear Information System (INIS)
Beaumel, D.; Fortier, S.; Gales, S.; Guillot, J.; Crawley, G.M.; Massolo, C.P.; Renteria, M.
1993-01-01
The neutron decay of high-lying single-particle states in 209 Pb excited by means of the (α, 3 He) reaction has been investigated at 122 MeV incident energy using the multidetector array EDEN. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in 208 Pb. The structure located between 8.5 and 12 MeV excitation energy in 209 Pb displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3 - ,5 - ) of 208 Pb. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model. (authors). 24 refs., 16 figs., 2 tabs
Probing the type of anomalous diffusion with single-particle tracking.
Ernst, Dominique; Köhler, Jürgen; Weiss, Matthias
2014-05-07
Many reactions in complex fluids, e.g. signaling cascades in the cytoplasm of living cells, are governed by a diffusion-driven encounter of reactants. Yet, diffusion in complex fluids often exhibits an anomalous characteristic ('subdiffusion'). Since different types of subdiffusion have distinct effects on timing and equilibria of chemical reactions, a thorough determination of the reactants' type of random walk is key to a quantitative understanding of reactions in complex fluids. Here we introduce a straightforward and simple approach for determining the type of subdiffusion from single-particle tracking data. Unlike previous approaches, our method also is sensitive to transient subdiffusion phenomena, e.g. obstructed diffusion below the percolation threshold. We validate our strategy with data from experiment and simulation.
Fractal behavior of single-particle trajectories and isosets in isotropic and anisotropic fluids
International Nuclear Information System (INIS)
Kalia, R.K.; Vashishta, P.; de Leeuw, S.W.
1985-08-01
Molecular dynamics simulations for a variety of systems in 2 spatial dimensions reveal fractual behavior associated with trajectories and isosets of single particle motion. The fractual dimensions of trajectories and isosets are 2 and 0.5, respectively, irrespective of the nature of the interparticle interaction or thermodynamic state of the system. Recently, we have investigated the fractual behavior of diffusing Ag ions in the superionic phase of Ag 2 S. MD calculations have shown that the Ag ions diffuse anisotropically along certain directions in the lattice of S particles. Fractual dimensions D and anti D for Ag ions are again 2 and 0.5, respectively. These results confirm the universal nature of fractual dimensions of trails and isosets
International Nuclear Information System (INIS)
Esaka, Fumitaka; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo
2006-01-01
The technique of single particle transfer was applied to quantitative analysis with total-reflection X-ray fluorescence (TXRF) spectrometry. The technique was evaluated by performing quantitative analysis of individual Cu particles with diameters between 3.9 and 13.2 μm. The direct quantitative analysis of the Cu particle transferred onto a Si carrier gave a discrepancy between measured and calculated Cu amounts due to the absorption effects of incident and fluorescent X-rays within the particle. By the correction for the absorption effects, the Cu amounts in individual particles could be determined with the deviation within 10.5%. When the Cu particles were dissolved with HNO 3 solution prior to the TXRF analysis, the deviation was improved to be within 3.8%. In this case, no correction for the absorption effects was needed for quantification
Applications of differential algebra to single-particle dynamics in storage rings
International Nuclear Information System (INIS)
Yan, Y.
1991-09-01
Recent developments in the use of differential algebra to study single-particle beam dynamics in charged-particle storage rings are the subject of this paper. Chapter 2 gives a brief review of storage rings. The concepts of betatron motion and synchrotron motion, and their associated resonances, are introduced. Also introduced are the concepts of imperfections, such as off-momentum, misalignment, and random and systematic errors, and their associated corrections. The chapter concludes with a discussion of numerical simulation principles and the concept of one-turn periodic maps. In Chapter 3, the discussion becomes more focused with the introduction of differential algebras. The most critical test for differential algebraic mapping techniques -- their application to long-term stability studies -- is discussed in Chapter 4. Chapter 5 presents a discussion of differential algebraic treatment of dispersed betatron motion. The paper concludes in Chapter 6 with a discussion of parameterization of high-order maps
Singlet-triplet splittings from the virial theorem and single-particle excitation energies
Becke, Axel D.
2018-01-01
The zeroth-order (uncorrelated) singlet-triplet energy difference in single-particle excited configurations is 2Kif, where Kif is the Coulomb self-energy of the product of the transition orbitals. Here we present a non-empirical, virial-theorem argument that the correlated singlet-triplet energy difference should be half of this, namely, Kif. This incredibly simple result gives vertical HOMO-LUMO excitation energies in small-molecule benchmarks as good as the popular TD-B3LYP time-dependent approach to excited states. For linear acenes and nonlinear polycyclic aromatic hydrocarbons, the performance is significantly better than TD-B3LYP. In addition to the virial theorem, the derivation borrows intuitive pair-density concepts from density-functional theory.
Dragonfly: an implementation of the expand-maximize-compress algorithm for single-particle imaging.
Ayyer, Kartik; Lan, Ti-Yen; Elser, Veit; Loh, N Duane
2016-08-01
Single-particle imaging (SPI) with X-ray free-electron lasers has the potential to change fundamentally how biomacromolecules are imaged. The structure would be derived from millions of diffraction patterns, each from a different copy of the macromolecule before it is torn apart by radiation damage. The challenges posed by the resultant data stream are staggering: millions of incomplete, noisy and un-oriented patterns have to be computationally assembled into a three-dimensional intensity map and then phase reconstructed. In this paper, the Dragonfly software package is described, based on a parallel implementation of the expand-maximize-compress reconstruction algorithm that is well suited for this task. Auxiliary modules to simulate SPI data streams are also included to assess the feasibility of proposed SPI experiments at the Linac Coherent Light Source, Stanford, California, USA.
Tran Hy, J
1998-01-01
This thesis describes some new studies of the effects of cubic nonlinearities arising from image-charge forces and octupole magnets on the transverse beam dynamics of proton synchrotrons and storage rings, and also a study of the damping of coherent oscillations using a feed-back damper. In the latter case, various corrective algorithms were modeled using linear one-turn maps. Kicks of fixed amplitude but appropriate sign were shown to provide linear damping and no coherent tune shift, though the rate predicted analytically was somewhat higher than that observed in simulations. This algorithm gave much faster damping (for equal power) than conventional proportional kicks, which damp exponentially. Two single-particle effects of the image-change force were investigated: distortion of the momentum dispersion function and amplitude dependence of the betatron tunes (resulting in tune spread). The former is calculated using transfer maps and the method of undetermined coefficients, the latter by solving the cubic ...
Burnout of pulverized biomass particles in large scale boiler - Single particle model approach
Energy Technology Data Exchange (ETDEWEB)
Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero [VTT Technical Research Centre of Finland, Box 1603, 40101 Jyvaeskylae (Finland); Soerensen, Lasse Holst [ReaTech/ReAddit, Frederiksborgsveij 399, Niels Bohr, DK-4000 Roskilde (Denmark); Clausen, Soennik [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Berg, Mogens [ENERGI E2 A/S, A.C. Meyers Vaenge 9, DK-2450 Copenhagen SV (Denmark)
2010-05-15
Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. (author)
Many-body calculations with deuteron based single-particle bases and their associated natural orbits
Puddu, G.
2018-06-01
We use the recently introduced single-particle states obtained from localized deuteron wave-functions as a basis for nuclear many-body calculations. We show that energies can be substantially lowered if the natural orbits (NOs) obtained from this basis are used. We use this modified basis for {}10{{B}}, {}16{{O}} and {}24{{Mg}} employing the bare NNLOopt nucleon–nucleon interaction. The lowering of the energies increases with the mass. Although in principle NOs require a full scale preliminary many-body calculation, we found that an approximate preliminary many-body calculation, with a marginal increase in the computational cost, is sufficient. The use of natural orbits based on an harmonic oscillator basis leads to a much smaller lowering of the energies for a comparable computational cost.
Single-Particle Momentum Distributions of Efimov States in Mixed-Species Systems
DEFF Research Database (Denmark)
T. Yamashita, M.; F. Bellotti, F.; Frederico, T.
2013-01-01
to derive formulas for the scaling factor of the Efimov spectrum for any mass ratio assuming either that two or three of the two-body subsystems have a bound state at zero energy. We consider the single-particle momentum distribution analytically and numerically and analyse the tail of the momentum......We solve the three-body bound state problem in three dimensions for mass imbalanced systems of two identical bosons and a third particle in the universal limit where the interactions are assumed to be of zero-range. The system displays the Efimov effect and we use the momentum-space wave equation...... distribution to obtain the three-body contact parameter. Our finding demonstrate that the functional form of the three-body contact term depends on the mass ratio and we obtain an analytic expression for this behavior. To exemplify our results, we consider mixtures of Lithium with either two Caesium or Rubium...
Experimental study of single-particle inclusive hadron scattering and associated multiplicities
International Nuclear Information System (INIS)
Brenner, A.E.; Carey, D.C.; Elias, J.E.; Garbincius, P.H.; Mikenberg, G.; Polychronakos, V.A.; Aitkenhead, W.; Barton, D.S.; Brandenburg, G.W.; Busza, W.; Dobrowolski, T.; Friedman, J.I.; Kendall, H.W.; Lyons, T.; Nelson, B.; Rosenson, L.; Toy, W.; Verdier, R.; Votta, L.; Chiaradia, M.T.; DeMarzo, C.; Favuzzi, C.; Germinario, G.; Guerriero, L.; LaVopa, P.; Maggi, G.; Posa, F.; Selvaggi, G.; Spinelli, P.; Waldner, F.; Meunier, R.; Cutts, D.; Dulude, R.S.; Lanou, R.E. Jr.; Massimo, J.T.
1982-01-01
An experiment using the Fermilab single arm spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied the reactions a+p→c+X where a and c were π +- , K +- , p, or p-bar. Extensive measurements were made at 100 and 175 GeV/c beam momenta with the outgoing hadrons detected in the SAS covering a kinematic range 0.12< x<1.0 and p/sub T/<1.25 GeV/c. Additional data covering a more restricted range in x were also gathered at 70 GeV/c incident momentum. In this high-statistics experiment, the identification of both the incoming and outgoing charged hadrons were made with a total of eight Cerenkov counters. New and extensive single-particle inclusive data for charged-particle production in low-p/sub T/ hadronic fragmentation are presented. The average associated charged-particle multiplicity and pseudorapidity distributions are also given
Evaluation strategies for isotope ratio measurements of single particles by LA-MC-ICPMS.
Kappel, S; Boulyga, S F; Dorta, L; Günther, D; Hattendorf, B; Koffler, D; Laaha, G; Leisch, F; Prohaska, T
2013-03-01
Data evaluation is a crucial step when it comes to the determination of accurate and precise isotope ratios computed from transient signals measured by multi-collector-inductively coupled plasma mass spectrometry (MC-ICPMS) coupled to, for example, laser ablation (LA). In the present study, the applicability of different data evaluation strategies (i.e. 'point-by-point', 'integration' and 'linear regression slope' method) for the computation of (235)U/(238)U isotope ratios measured in single particles by LA-MC-ICPMS was investigated. The analyzed uranium oxide particles (i.e. 9073-01-B, CRM U010 and NUSIMEP-7 test samples), having sizes down to the sub-micrometre range, are certified with respect to their (235)U/(238)U isotopic signature, which enabled evaluation of the applied strategies with respect to precision and accuracy. The different strategies were also compared with respect to their expanded uncertainties. Even though the 'point-by-point' method proved to be superior, the other methods are advantageous, as they take weighted signal intensities into account. For the first time, the use of a 'finite mixture model' is presented for the determination of an unknown number of different U isotopic compositions of single particles present on the same planchet. The model uses an algorithm that determines the number of isotopic signatures by attributing individual data points to computed clusters. The (235)U/(238)U isotope ratios are then determined by means of the slopes of linear regressions estimated for each cluster. The model was successfully applied for the accurate determination of different (235)U/(238)U isotope ratios of particles deposited on the NUSIMEP-7 test samples.
Directory of Open Access Journals (Sweden)
Samson Abramsky
2015-11-01
Full Text Available Maxwell's Demon, 'a being whose faculties are so sharpened that he can follow every molecule in its course', has been the centre of much debate about its abilities to violate the second law of thermodynamics. Landauer's hypothesis, that the Demon must erase its memory and incur a thermodynamic cost, has become the standard response to Maxwell's dilemma, and its implications for the thermodynamics of computation reach into many areas of quantum and classical computing. It remains, however, still a hypothesis. Debate has often centred around simple toy models of a single particle in a box. Despite their simplicity, the ability of these systems to accurately represent thermodynamics (specifically to satisfy the second law and whether or not they display Landauer Erasure, has been a matter of ongoing argument. The recent Norton-Ladyman controversy is one such example. In this paper we introduce a programming language to describe these simple thermodynamic processes, and give a formal operational semantics and program logic as a basis for formal reasoning about thermodynamic systems. We formalise the basic single-particle operations as statements in the language, and then show that the second law must be satisfied by any composition of these basic operations. This is done by finding a computational invariant of the system. We show, furthermore, that this invariant requires an erasure cost to exist within the system, equal to kTln2 for a bit of information: Landauer Erasure becomes a theorem of the formal system. The Norton-Ladyman controversy can therefore be resolved in a rigorous fashion, and moreover the formalism we introduce gives a set of reasoning tools for further analysis of Landauer erasure, which are provably consistent with the second law of thermodynamics.
Single particle Schroedinger fluid and moments of inertia of deformed nuclei
International Nuclear Information System (INIS)
Doma, S.B.
2002-01-01
The authors have applied the theory of the single-particle Schroedinger fluid to the nuclear collective motion of axially deformed nuclei. A counter example of an arbitrary number of independent nucleons in the anisotropic harmonic oscillator potential at the equilibrium deformation has been also given. Moreover, the ground states of the doubly even nuclei in the s-d shell 20 Ne, 24 Mg, 28 Si, 32 S and 36 Ar are constructed by filling the single-particle states corresponding to the possible values of the number of quanta of excitations n x , n y and n z . Accordingly, the cranking-model, the rigid-body model and the equilibrium-model moments of inertia of these nuclei are calculated as functions of the oscillator parameters ℎω x , ℎω y and ℎω z which are given in terms of the non deformed value ℎω 0 0 , depending on the mass number A, the number of neutrons N, the number of protons Z, and the deformation parameter β. The calculated values of the cranking-model moments of inertia of these nuclei are in good agreement with the corresponding experiential values and show that the considered axially deformed nuclei may have oblate as well as prolate shapes and that the nucleus 24 Mg is the only one which is highly deformed. The rigid-body model and the equilibrium-model moments of inertia of the two nuclei 20 Ne and 24 Mg are also in good agreement with the corresponding experimental values
Energy Technology Data Exchange (ETDEWEB)
Haefner, Petra [Ludwig Maximilian Univ., Munich (Germany)
2008-07-31
The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with theW boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t $\\bar{t}$ →W^{±}W^{∓} b$\\bar{b}$ →q $\\bar{t}$lnb$\\bar{b}$ is the ”golden channel” for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb^{-1} of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m_{t} = (169.2±3.5(stat.)±1.0(syst.)) GeV . The
International Nuclear Information System (INIS)
Kirsch, Matthias
2009-01-01
exceeds the Standard Model expectation by 2 standard deviations. The result of the analysis presented here is in good agreement with the result of σ(p anti p→tb+X,tqb+X)=4.8± 1.3 pb, obtained from the combination of three other analyses performed on the same data set. From the cross section measurement a measurement of the strength vertical stroke V tb x f 1 L vertical stroke of the V-A coupling at the Wtb-vertex has been extracted. The result is vertical stroke V tb x f 1 L vertical stroke =1.42 -0.20 +0.21 . This value is above the Standard Model expectation by about 2∝standard deviations. The measurement agrees within uncertainties with the measurement of vertical stroke V tb x f 1 L vertical stroke =1.31 -0.21 +0.25 obtained by another analysis performed on the same data set. Constraining the prior of this measurement to the interval [0,1], i.e. setting the strength of the left-handed coupling f 1 L =1, a result for the CKM matrix element vertical stroke V tb vertical stroke has been determined to vertical stroke V tb vertical stroke =1.00 -0.08 +0.00 . From the posterior probability density of this measurement a lower limit for V tb has been set at 95% confidence level: vertical stroke V tb vertical stroke >0.79 rate at 95% C.L. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)
2011-03-15
Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Rousseau, P [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires
1967-06-01
In a first part, after a brief recall concerning 'planar' technology we discuss the various parasitic elements associated with integrated circuits components. Mathematical formulae of these elements are derived. In a second part, we present a matrix of 22 transistors and 12 resistors which has been realized. This matrix enables the integration of the major part of nuclear circuits. Some of the obtained circuits are shown, particularly an emitter coupled logic gate which presents good electrical behaviour. (author) [French] Dans uns premiere partie, apres un bref rappel de la technologie 'planar' nous etudions les divers elements parasites associes a tout composant d'un circuit integre. Un developpement sommaire des expressions mathematiques de ces elements est propose. Dans une seconde partie nous presentons la matrice de 22 transistors et 12 resistances que nous avons realisee. Cette matrice repond aux principaux besoins de l'electronique nucleaire. Nous proposons ensuite quelques exemples de circuits realises a partir de cette matrice dont notamment une porte logique a emetteurs couples de performances tres interessantes. (auteur)
International Nuclear Information System (INIS)
Lee, Byeong Hae
1992-02-01
This book gives descriptions of basic finite element method, which includes basic finite element method and data, black box, writing of data, definition of VECTOR, definition of matrix, matrix and multiplication of matrix, addition of matrix, and unit matrix, conception of hardness matrix like spring power and displacement, governed equation of an elastic body, finite element method, Fortran method and programming such as composition of computer, order of programming and data card and Fortran card, finite element program and application of nonelastic problem.
International Nuclear Information System (INIS)
Karjou, J.
2007-01-01
The effect of matrix contents on the detection limit of total reflection X-ray fluorescence analysis was experimentally investigated using a set of multielement standard solutions (500 ng/mL of each element) in variable concentrations of NH 4 NO 3 . It was found that high matrix concentration, i.e. 0.1-10% NH 4 NO 3 , had a strong effect on the detection limits for all investigated elements, whereas no effect was observed at lower matrix concentration, i.e. 0-0.1% NH 4 NO 3 . The effect of soil and blood sample masses on the detection limit was also studied. The results showed decreasing the detection limit (in concentration unit, μg/g) with increasing the sample mass. However, the detection limit increased (in mass unit, ng) with increasing sample mass. The optimal blood sample mass of ca. 200 μg was sufficient to improve the detection limit of Se determination by total reflection X-ray fluorescence. The capability of total reflection X-ray fluorescence to analyze different kinds of samples was discussed with respect to the accuracy and detection limits based on certified and reference materials. Direct analysis of unknown water samples from several sources was also presented in this work
Bodewig, E
1959-01-01
Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well
Single-particle properties of N = 12 to N = 20 silicon isotopes within the dispersive optical model
Bespalova, O. V.; Ermakova, T. A.; Klimochkina, A. A.; Spasskaya, T. I.
2017-09-01
Experimental neutron and proton single-particle energies in N = 12 to N = 20 silicon isotopes and data on neutron and proton scattering by nuclei of the isotope 28Si are analyzed on the basis of the dispersive optical model. Good agreement with available experimental data was attained. The occupation probabilities calculated for the single-particle states in question suggest a parallel-type filling of the 1 d and 2 s 1/2 neutron states in the isotopes 26,28,30,32,34Si. The single-particle spectra being considered are indicative of the closure of the Z = 14 proton subshell in the isotopes 30,32,34Si and the N = 20 neutron shell.
International Nuclear Information System (INIS)
Vasin, B.D.; Ivanov, V.A.; Shchetinskij, A.V.; Vavilov, S.K.; Savochkin, Yu.P.; Bychkov, A.V.; Kormilitsyn, M.V.
2005-01-01
A consideration is given to pyrochemical processes suitable for separation of uranium dioxide from structural materials when reprocessing cermet type fuel elements. The estimation of the possibility to apply liquid antimony and bismuth, potassium and copper chlorides melts is made. The specimens compacted of copper and uranium dioxide powders in a stainless steel can are used as simulators of fuel element sections. It is concluded that the dissolution of structural materials in molten salts at the stage of uranium dioxide concentration is the process of choice for reprocessing of dispersion type fuel elements [ru