Wilson loops in minimal surfaces

International Nuclear Information System (INIS)

Drukker, Nadav; Gross, David J.; Ooguri, Hirosi

1999-01-01

The AdS/CFT correspondence suggests that the Wilson loop of the large N gauge theory with N = 4 supersymmetry in 4 dimensions is described by a minimal surface in AdS 5 x S 5 . The authors examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which the authors call BPS loops, whose expectation values are free from ultra-violet divergence. They formulate the loop equation for such loops. To the extent that they have checked, the minimal surface in AdS 5 x S 5 gives a solution of the equation. The authors also discuss the zig-zag symmetry of the loop operator. In the N = 4 gauge theory, they expect the zig-zag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. They will show how this is realized for the minimal surface

Wilson loops and minimal surfaces

International Nuclear Information System (INIS)

Drukker, Nadav; Gross, David J.; Ooguri, Hirosi

1999-01-01

The AdS-CFT correspondence suggests that the Wilson loop of the large N gauge theory with N=4 supersymmetry in four dimensions is described by a minimal surface in AdS 5 xS 5 . We examine various aspects of this proposal, comparing gauge theory expectations with computations of minimal surfaces. There is a distinguished class of loops, which we call BPS loops, whose expectation values are free from ultraviolet divergence. We formulate the loop equation for such loops. To the extent that we have checked, the minimal surface in AdS 5 xS 5 gives a solution of the equation. We also discuss the zigzag symmetry of the loop operator. In the N=4 gauge theory, we expect the zigzag symmetry to hold when the loop does not couple the scalar fields in the supermultiplet. We will show how this is realized for the minimal surface. (c) 1999 The American Physical Society

BPS Wilson loops and Bremsstrahlung function in ABJ(M): a two loop analysis

Energy Technology Data Exchange (ETDEWEB)

Bianchi, Marco S. [Institut für Physik, Humboldt-Universität zu Berlin,Newtonstraße 15, 12489 Berlin (Germany); Griguolo, Luca [Dipartimento di Fisica e Scienze della Terra, Università di Parmaand INFN Gruppo Collegato di Parma,Viale G.P. Usberti 7/A, 43100 Parma (Italy); Leoni, Matias [Physics Department, FCEyN-UBA & IFIBA-CONICETCiudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Penati, Silvia [Dipartimento di Fisica, Università di Milano-Bicoccaand INFN, Sezione di Milano-Bicocca,Piazza della Scienza 3, I-20126 Milano (Italy); Seminara, Domenico [Dipartimento di Fisica, Università di Firenzeand INFN Sezione di Firenze,via G. Sansone 1, 50019 Sesto Fiorentino (Italy)

2014-06-19

We study a family of circular BPS Wilson loops in N=6 super Chern-Simons-matter theories, generalizing the usual 1/2-BPS circle. The scalar and fermionic couplings depend on two deformation parameters and these operators can be considered as the ABJ(M) counterpart of the DGRT latitudes defined in N=4 SYM. We perform a complete two-loop analysis of their vacuum expectation value, discuss the appearance of framing-like phases and propose a general relation with cohomologically equivalent bosonic operators. We make an all-loop proposal for computing the Bremsstrahlung function associated to the 1/2-BPS cusp in terms of these generalized Wilson loops. When applied to our two-loop result it reproduces the known expression. Finally, we comment on the generalization of this proposal to the bosonic 1/6-BPS case.

A profusion of 1/2 BPS Wilson loops in N=4 Chern-Simons-matter theories

International Nuclear Information System (INIS)

Cooke, Michael; Drukker, Nadav; Trancanelli, Diego

2015-01-01

We initiate the study of 1/2 BPS Wilson loops in N=4 Chern-Simons-matter theories in three dimensions. We consider a circular or linear quiver with Chern-Simons levels k, −k and 0, and focus on loops preserving one of the two SU(2) subgroups of the R-symmetry. In the cases with no vanishing Chern-Simons levels, we find a pair of Wilson loops for each pair of adjacent nodes on the quiver connected by a hypermultiplet (nodes connected by twisted hypermultiplets have Wilson loops preserving another set of supercharges). We expect this classical pairwise degeneracy to be lifted by quantum corrections. In the case with nodes with vanishing Chern-Simons terms connected by twisted hypermultiplets, we find that the usual 1/4 BPS Wilson loops are automatically enlarged to 1/2 BPS, as happens also in 3-dimensional Yang-Mills theory. When the nodes with vanishing Chern-Simons levels are connected by untwisted hypermultiplets, we do not find any Wilson loops coupling to those nodes which are classically invariant. Rather, we find several loops whose supersymmetry variation, while non zero, vanishes in any correlation function, so is weakly zero. We expect only one linear combination of those Wilson loops to remain BPS when quantum corrections are included. We analyze the M-theory duals of those Wilson loops and comment on their degeneracy. We also show that these Wilson loops are cohomologically equivalent to certain 1/4 BPS Wilson loops whose expectation value can be evaluated by the appropriate localized matrix model.

Symmetries of Maldacena-Wilson loops from integrable string theory

International Nuclear Information System (INIS)

Muenkler, Hagen

2017-01-01

This thesis discusses hidden symmetries within N=4 supersymmetric Yang-Mills theory or its AdS/CFT dual, string theory in AdS 5 x S 5 . Here, we focus on the Maldacena-Wilson loop, which is a suitable object for this study since its vacuum expectation value is finite for smooth contours and the conjectured duality to scattering amplitudes provides a conceptual path to transfer its symmetries to other observables. Its strong-coupling description via minimal surfaces in AdS 5 allows to construct the symmetries from the integrability of the underlying classical string theory. This approach has been utilized before to derive a strong-coupling Yangian symmetry of the Maldacena-Wilson loop and describe equiareal deformations of minimal surfaces in AdS 3 . These two findings are connected and extended in the present thesis. In order to discuss the symmetries systematically, we first discuss the symmetry structure of the underlying string model. The discussion can be generalized to the discussion of generic symmetric space models. For these, we find that the symmetry which generates the equiareal deformations of minimal surfaces in AdS 3 has a central role in the symmetry structure of the model: It acts as a raising operator on the infinite tower of conserved charges, thus generating the spectral parameter, and can be employed to construct all symmetry variations from the global symmetry of the model. It is thus referred to as the master symmetry of symmetric space models. Additionally, the algebra of the symmetry variations and the conserved charges is worked out. For the concrete case of minimal surfaces in AdS 5 , we discuss the deformation of the four-cusp solution, which provides the dual description of the four-gluon scattering amplitude. This marks the first step toward transferring the master symmetry to scattering amplitudes. Moreover, we compute the master and Yangian symmetry variations of generic, smooth boundary curves. The results leads to a coupling

Symmetries of Maldacena-Wilson loops from integrable string theory

Energy Technology Data Exchange (ETDEWEB)

Muenkler, Hagen

2017-09-11

This thesis discusses hidden symmetries within N=4 supersymmetric Yang-Mills theory or its AdS/CFT dual, string theory in AdS{sub 5} x S{sup 5}. Here, we focus on the Maldacena-Wilson loop, which is a suitable object for this study since its vacuum expectation value is finite for smooth contours and the conjectured duality to scattering amplitudes provides a conceptual path to transfer its symmetries to other observables. Its strong-coupling description via minimal surfaces in AdS{sub 5} allows to construct the symmetries from the integrability of the underlying classical string theory. This approach has been utilized before to derive a strong-coupling Yangian symmetry of the Maldacena-Wilson loop and describe equiareal deformations of minimal surfaces in AdS{sub 3}. These two findings are connected and extended in the present thesis. In order to discuss the symmetries systematically, we first discuss the symmetry structure of the underlying string model. The discussion can be generalized to the discussion of generic symmetric space models. For these, we find that the symmetry which generates the equiareal deformations of minimal surfaces in AdS{sub 3} has a central role in the symmetry structure of the model: It acts as a raising operator on the infinite tower of conserved charges, thus generating the spectral parameter, and can be employed to construct all symmetry variations from the global symmetry of the model. It is thus referred to as the master symmetry of symmetric space models. Additionally, the algebra of the symmetry variations and the conserved charges is worked out. For the concrete case of minimal surfaces in AdS{sub 5}, we discuss the deformation of the four-cusp solution, which provides the dual description of the four-gluon scattering amplitude. This marks the first step toward transferring the master symmetry to scattering amplitudes. Moreover, we compute the master and Yangian symmetry variations of generic, smooth boundary curves. The results

Holography of Wilson-loop expectation values with local operator insertions

International Nuclear Information System (INIS)

Miwa, Akitsugu; Yoneya, Tamiaki

2006-01-01

We study the expectation values of Wilson-loop operators with the insertions of local operators Z J and Z-bar J for large J from the bulk viewpoint of AdS/CFT correspondence. Classical solutions of strings attached to such deformed Wilson loops at the conformal boundary are constructed and are applied to the computation of Wilson-loop expectation values. We argue that in order to have such solutions for general insertions at finite positions in the base spacetime of the gauge theory, it is crucial to interpret the holographic correspondence in the semi-classical picture as a tunneling phenomenon, as has been previously established for holographic computations of correlators of BMN operators. This also requires to use the Euclideanized AdS background and Euclidean super Yang-Mills theory

Wilson loops in superconformal Chern-Simons theory and fundamental strings in Anti-de Sitter supergravity dual

International Nuclear Information System (INIS)

Rey, Soo-Jong; Suyama, Takao; Yamaguchi, Satoshi

2009-01-01

We study Wilson loop operators in three-dimensional, N = 6 superconformal Chern-Simons theory dual to IIA superstring theory on AdS 4 x CP 3 . Novelty of Wilson loop operators in this theory is that, for a given contour, there are two linear combinations of Wilson loop transforming oppositely under time-reversal transformation. We show that one combination is holographically dual to IIA fundamental string, while orthogonal combination is set to zero. We gather supporting evidences from detailed comparative study of generalized time-reversal transformations in both D2-brane worldvolume and ABJM theories. We then classify supersymmetric Wilson loops and find at most 1/6 supersymmetry. We next study Wilson loop expectation value in planar perturbation theory. For circular Wilson loop, we find features remarkably parallel to circular Wilson loop in N = 4 super Yang-Mills theory in four dimensions. First, all odd loop diagrams vanish identically and even loops contribute nontrivial contributions. Second, quantum corrected gauge and scalar propagators take the same form as those of N = 4 super Yang-Mills theory. Combining these results, we propose that expectation value of circular Wilson loop is given by Wilson loop expectation value in pure Chern-Simons theory times zero-dimensional Gaussian matrix model whose variance is specified by an interpolating function of 't Hooft coupling. We suggest the function interpolates smoothly between weak and strong coupling regime, offering new test ground of the AdS/CFT correspondence.

Very high order lattice perturbation theory for Wilson loops

International Nuclear Information System (INIS)

Horsley, R.

2010-10-01

We calculate perturbativeWilson loops of various sizes up to loop order n=20 at different lattice sizes for pure plaquette and tree-level improved Symanzik gauge theories using the technique of Numerical Stochastic Perturbation Theory. This allows us to investigate the behavior of the perturbative series at high orders. We observe differences in the behavior of perturbative coefficients as a function of the loop order. Up to n=20 we do not see evidence for the often assumed factorial growth of the coefficients. Based on the observed behavior we sum this series in a model with hypergeometric functions. Alternatively we estimate the series in boosted perturbation theory. Subtracting the estimated perturbative series for the average plaquette from the non-perturbative Monte Carlo result we estimate the gluon condensate. (orig.)

SU(2) string tension from large Wilson loops

International Nuclear Information System (INIS)

Karsch, F.; Lang, C.B.

1984-01-01

We determine expectation values of Wilson loops and correlations of Polyakov loops on lattices of size 10 X 16 3 and 8 X 16 3 at β values 2.25 and 2.375. Utilizing a recently proposed method to reduce the variance of loop expectation values, we are able to measure loops up to 6 X 6. We find Λsub(L) = 0.0151 +- 0.0006√sub(K) at β = 2.375. (orig.)

Baryon Regge trajectories from the area-law of Wilson loop

International Nuclear Information System (INIS)

Simonov, Yu.A.

1989-01-01

In the proper-time path integral representation of the three-quark Green function, baryon masses are calculated for large angular momenta L. Dynamics is given by vacuum background fields in the Wilson loop. Assuming an area law for large Wilson loops one obtains linear baryon Regge trajectories with the same slope as for mesons. For large L the baryon has an asymmetric structure of the quark-diquark type. Dynamic masses of the quark and diquark are generated, which grow with L. 8 refs

Wilson loops in 5d $\\mathcal{N}=1$ theories and S-duality arXiv

CERN Document Server

Assel, Benjamin

We study the action of S-duality on half-BPS Wilson loop operators in 5d $\\mathcal{N}=1$ theories. The duality is the statement that different massive deformations of a single 5d SCFT are described by different gauge theories, or equivalently that the SCFT points in parameter space of two gauge theories coincide. The pairs of dual theories that we study are realized by brane webs in type IIB string theory that are S-dual to each other. We focus on $SU(2)$ SQCD theories with $N_f \\le 4$ flavors, which are self-dual, and on $SU(3)$ SQCD theories, which are dual to $SU(2)^2$ quiver theories. From string theory engineering we predict that Wilson loops are mapped to dual Wilson loops under S-duality. We confirm the predictions with exact computations of Wilson loop VEVs, which we extract from the 5d half-index in the presence of auxiliary loop operators (also known as higher qq-characters) sourced by D3 branes placed in the brane webs. A special role is played by Wilson loops in tensor products of the (anti)fundam...

Wilson loops in very high order lattice perturbation theory

International Nuclear Information System (INIS)

Ilgenfritz, E.M.; Nakamura, Y.; Perlt, H.; Schiller, A.; Rakow, P.E.L.; Schierholz, G.; Regensburg Univ.

2009-10-01

We calculate Wilson loops of various sizes up to loop order n=20 for lattice sizes of L 4 (L=4,6,8,12) using the technique of Numerical Stochastic Perturbation Theory in quenched QCD. This allows to investigate the behaviour of the perturbative series at high orders. We discuss three models to estimate the perturbative series: a renormalon inspired fit, a heuristic fit based on an assumed power-law singularity and boosted perturbation theory. We have found differences in the behavior of the perturbative series for smaller and larger Wilson loops at moderate n. A factorial growth of the coefficients could not be confirmed up to n=20. From Monte Carlo measured plaquette data and our perturbative result we estimate a value of the gluon condensate left angle (α)/(π)GG right angle. (orig.)

Probing Wilson loops in N=4 Chern–Simons-matter theories at weak coupling

Directory of Open Access Journals (Sweden)

Luca Griguolo

2016-02-01

Full Text Available For three-dimensional N=4 super-Chern–Simons-matter theories associated to necklace quivers U(N0×U(N1×⋯U(N2r−1, we study at quantum level the two kinds of 1/2 BPS Wilson loop operators recently introduced in arXiv:1506.07614. We perform a two-loop evaluation and find the same result for the two kinds of operators, so moving to higher loops a possible quantum uplift of the classical degeneracy. We also compute the 1/4 BPS bosonic Wilson loop and discuss the quantum version of the cohomological equivalence between fermionic and bosonic Wilson loops. We compare the perturbative result with the Matrix Model prediction and find perfect matching, after identification and remotion of a suitable framing factor. Finally, we discuss the potential appearance of three-loop contributions that might break the classical degeneracy and briefly analyze possible implications on the BPS nature of these operators.

On strong-coupling correlation functions of circular Wilson loops and local operators

International Nuclear Information System (INIS)

Alday, Luis F; Tseytlin, Arkady A

2011-01-01

Motivated by the problem of understanding 3-point correlation functions of gauge-invariant operators in N=4 super Yang-Mills theory we consider correlators involving Wilson loops and a 'light' operator with fixed quantum numbers. At leading order in the strong-coupling expansion such correlators are given by the 'light' vertex operator evaluated on a semiclassical string world surface ending on the corresponding loops at the boundary of AdS 5 x S 5 . We study in detail the example of a correlator of two concentric circular Wilson loops and a dilaton vertex operator. The resulting expression is given by an integral of combinations of elliptic functions and can be computed analytically in some special limits. We also consider a generalization of the minimal surface ending on two circles to the case of non-zero angular momentum J in S 5 and discuss a special limit when one of the Wilson loops is effectively replaced by a 'heavy' operator with charge J. (paper)

Wilson loops, instantons and quantum mechanics

International Nuclear Information System (INIS)

Schiereck, Marc

2014-05-01

In this thesis we examine two different problems. The first is the computation of vacuum expectation values of Wilson loop operators in ABJM theory, the other problem is finding the instanton series of the refined topological string on certain local Calabi-Yau geometries in the Nekrasov-Shatashvili limit. Based on the description of ABJM theory as a matrix model, it is possible to find a description of it in terms of an ideal Fermi gas with a non-trivial one-particle Hamiltonian. The vacuum-expectation-values of Wilson loop operators in ABJM theory correspond to averages of operators in the statistical-mechanical problem. Using the WKB expansion, it is possible to extract the full 1/N expansion of the vevs, up to exponentially small contributions, for arbitrary Chern-Simons coupling. We compute these vevs for the 1/6 and 1/2 BPS Wilson loops at any winding number. These can be written in terms of the Airy function. The expressions we found reproduce the low genus results previously obtained in the 't Hooft expansion. In another problem we use mirror symmetry, quantum geometry and modularity properties of elliptic curves to calculate the refined free energies, given in terms of an instanton sum, in the Nekrasov-Shatashvili limit on non-compact toric Calabi-Yau manifolds, based on del Pezzo surfaces. Quantum geometry here is to be understood as a quantum deformed version of rigid special geometry, which has its origin in the quantum mechanical behavior of branes in the topological string B-model. We argue that in the Seiberg-Witten picture only the Coulomb parameters lead to quantum corrections, while the mass parameters remain uncorrected. In certain cases we also compute the expansion of the free energies at the orbifold point and the conifold locus. We compute the quantum corrections order by order on ℎ by deriving second order differential operators, which act on the classical periods.

Toward precision holography with supersymmetric Wilson loops

Energy Technology Data Exchange (ETDEWEB)

Faraggi, Alberto [Instituto de Física, Pontificia Universidad Católica de Chile,Casilla 306, Santiago (Chile); Zayas, Leopoldo A. Pando [The Abdus Salam International Centre for Theoretical Physics,Strada Costiera 11, 34014 Trieste (Italy); Michigan Center for Theoretical Physics, Department of Physics,University of Michigan, Ann Arbor, MI 48109 (United States); Silva, Guillermo A. [Instituto de Física de La Plata - CONICET & Departamento de Física - UNLP,C.C. 67, 1900 La Plata (Argentina); Trancanelli, Diego [Institute of Physics, University of São Paulo,05314-970 São Paulo (Brazil)

2016-04-11

We consider certain 1/4 BPS Wilson loop operators in SU(N)N=4 supersymmetric Yang-Mills theory, whose expectation value can be computed exactly via supersymmetric localization. Holographically, these operators are mapped to fundamental strings in AdS{sub 5}×S{sup 5}. The string on-shell action reproduces the large N and large coupling limit of the gauge theory expectation value and, according to the AdS/CFT correspondence, there should also be a precise match between subleading corrections to these limits. We perform a test of such match at next-to-leading order in string theory, by deriving the spectrum of quantum fluctuations around the classical string solution and by computing the corresponding 1-loop effective action. We discuss in detail the supermultiplet structure of the fluctuations. To remove a possible source of ambiguity in the ghost zero mode measure, we compare the 1/4 BPS configuration with the 1/2 BPS one, dual to a circular Wilson loop. We find a discrepancy between the string theory result and the gauge theory prediction, confirming a previous result in the literature. We are able to track the modes from which this discrepancy originates, as well as the modes that by themselves would give the expected result.

One-loop Wilson loops and the particle-interface potential in AdS/dCFT

Directory of Open Access Journals (Sweden)

Marius de Leeuw

2017-05-01

Full Text Available We initiate the calculation of quantum corrections to Wilson loops in a class of four-dimensional defect conformal field theories with vacuum expectation values based on N=4 super Yang–Mills theory. Concretely, we consider an infinite straight Wilson line, obtaining explicit results for the one-loop correction to its expectation value in the large-N limit. This allows us to extract the particle-interface potential of the theory. In a further double-scaling limit, we compare our results to those of a previous calculation in the dual string-theory set-up consisting of a D5-D3 probe-brane system with flux, and we find perfect agreement.

Surface representations of Wilson loop expectations in lattice gauge theory

International Nuclear Information System (INIS)

Brydges, D.C.; Giffen, C.; Durhuus, B.; Froehlich, J.

1986-01-01

Expectations of Wilson loops in lattice gauge theory with gauge group G=Z 2 , U(1) or SU(2) are expressed as weighted sums over surfaces with boundary equal to the loops labelling the observables. For G=Z 2 and U(1), the weights are all positive. For G=SU(2), the weights can have either sign depending on the Euler characteristic of the surface. Our surface (or flux sheet-) representations are partial resummations of the strong coupling expansion and provide some qualitative understanding of confinement. The significance of flux sheets with nontrivial topology for permanent confinement in the SU(2)-theory is elucidated. (orig.)

Dual conformal transformations of smooth holographic Wilson loops

Energy Technology Data Exchange (ETDEWEB)

Dekel, Amit [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

2017-01-19

We study dual conformal transformations of minimal area surfaces in AdS{sub 5}×S{sup 5} corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual space by means of T-duality, then we apply a conformal transformation and finally T-dualize back to the original space. The transformation maps between string solutions with different boundary contours. The boundary contours of the minimal surfaces are not mapped back to the AdS boundary, and the regularized area of the surface changes.

Wilson loops en la correspondencia AdS/CFT

OpenAIRE

Aguilera Damia, Jeremías

2017-01-01

Esta tesis está abocada al estudio de operadores no locales e invariantes de gauge, denominados Wilson loops, tanto a través de técnicas propias de teoría de cuerdas como por medio de técnicas avanzadas en teorías de gauge.

Perturbation calculations with Wilson loop

International Nuclear Information System (INIS)

Peixoto Junior, L.B.

1984-01-01

We present perturbative calculations with the Wilson loop (WL). The dimensional regularization method is used with a special attention concerning to the problem of divergences in the WL expansion in second and fourth orders, in three and four dimensions. We show that the residue in the pole, in 4d, of the fourth order graphs contribution sum is important for the charge renormalization. We compute up to second order the exact expression of the WL, in three-dimensional gauge theories with topological mass as well as its assimptotic behaviour for small and large distances. the author [pt

Mandelstam cuts and light-like Wilson loops in N=4 SUSY

Energy Technology Data Exchange (ETDEWEB)

Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Prygarin, A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2010-08-15

We perform an analytic continuation of the two-loop remainder function for the six-point planar MHV amplitude in N=4 SUSY, found by Goncharov, Spradlin, Vergu and Volovich from the light-like Wilson loop representation. The remainder function is continued into a physical region, where all but two energy invariants are negative. It turns out to be pure imaginary in the multi-Regge kinematics, which is in an agreement with the predictions based on the Steinmann relations for the Regge poles and Mandelstam cut contributions. The leading term reproduces correctly the expression calculated by one of the authors in the BFKL approach, while the subleading term presents a result, that was not yet found with the use of the unitarity techniques. This supports the applicability of the Wilson loop approach to the planar MHV amplitudes in N=4 SUSY. (orig.)

Mandelstam cuts and light-like Wilson loops in N=4 SUSY

International Nuclear Information System (INIS)

Lipatov, L.N.; Prygarin, A.

2010-08-01

We perform an analytic continuation of the two-loop remainder function for the six-point planar MHV amplitude in N=4 SUSY, found by Goncharov, Spradlin, Vergu and Volovich from the light-like Wilson loop representation. The remainder function is continued into a physical region, where all but two energy invariants are negative. It turns out to be pure imaginary in the multi-Regge kinematics, which is in an agreement with the predictions based on the Steinmann relations for the Regge poles and Mandelstam cut contributions. The leading term reproduces correctly the expression calculated by one of the authors in the BFKL approach, while the subleading term presents a result, that was not yet found with the use of the unitarity techniques. This supports the applicability of the Wilson loop approach to the planar MHV amplitudes in N=4 SUSY. (orig.)

3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

International Nuclear Information System (INIS)

Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von

2014-09-01

We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large Q 2 limit, where the heavy flavor Wilson coefficients are known to factorize into light flavor Wilson coefficients and massive operator matrix elements. We describe the different techniques employed for the calculation and show the results in the case of the heavy flavor non-singlet and pure singlet contributions to the structure function F 2 (x,Q 2 ).

New WZW D-branes from the algebra of Wilson loop operators

International Nuclear Information System (INIS)

Monnier, Samuel

2009-01-01

We investigate the algebra generated by the topological Wilson loop operators in WZW models. Wilson loops describe the nontrivial fixed points of the boundary renormalization group flows triggered by Kondo perturbations. Their enveloping algebra therefore encodes all the fixed points which can be reached by sequences of Kondo flows. This algebra is easily described in the case of SU(2), but displays a very rich structure for higher rank groups. In the latter case, its action on known D-branes creates a profusion of new and generically non-rational D-branes. We describe their symmetries and the geometry of their worldvolumes. We briefly explain how to extend these results to coset models.

3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Hasselhuhn, A.; Schneider, C. [Johannes-Kepler-Univ. Linz (Austria). RISC; Behring, A.; Bluemlein, J.; Freitas, A. de; Raab, C.; Round, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Wissbrock, F. [Johannes-Kepler-Univ. Linz (Austria). RISC; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); IHES Institut des Hautes Etudes Scientifiques, Bures-sur-Yvette (France)

2014-09-15

We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large Q{sup 2} limit, where the heavy flavor Wilson coefficients are known to factorize into light flavor Wilson coefficients and massive operator matrix elements. We describe the different techniques employed for the calculation and show the results in the case of the heavy flavor non-singlet and pure singlet contributions to the structure function F{sub 2}(x,Q{sup 2}).

Perturbative evaluation of the Thermal Wilson Loop

International Nuclear Information System (INIS)

Gava, E.; Jengo, R.

1981-06-01

The Thermal Wilson Loop 0 sup(β) dtauA 0 (tau, x-vector)>, representing an order parameter for the gauge theory and expected to be zero in the confining phase, is perturbatively evaluated up to the O(g 4 ) included for an SU(N) pure Yang-Mills theory. This evaluation should be meaningful at high temperature, β → 0. Its behaviour is discussed and a possible need for non-perturbative instanton-like contributions is pointed out. (author)

Wilson loops on three-manifolds and their M2-brane duals

International Nuclear Information System (INIS)

Farquet, Daniel; Sparks, James

2014-01-01

We compute the large N limit of Wilson loop expectation values for a broad class of N=2 supersymmetric gauge theories defined on a general class of background three-manifolds M_3, diffeomorphic to S"3. We find a simple closed formula which depends on the background geometry only through a certain supersymmetric Killing vector field. The supergravity dual of such a Wilson loop is an M2-brane wrapping the M-theory circle, together with a complex curve Σ_2 in a self-dual Einstein manifold M_4, whose conformal boundary is M_3. We show that the regularized action of this M2-brane also depends only on the supersymmetric Killing vector, precisely reproducing the large N field theory computation.

On the amplitude/Wilson loop duality in N=2 SCQCD

Directory of Open Access Journals (Sweden)

Marta Leoni

2015-07-01

Full Text Available We compute the four-point amplitude with external adjoint particles in N=2 SCQCD at two loops using N=1 superspace Feynman diagrams, extending the results of arXiv:1406.7283. We consider the diagrammatic difference with the corresponding process of N=4 SYM finding a non-vanishing result, which is a non-trivial function of the kinematic variables. This demonstrates that in N=2 SCQCD, even in the sector with external particles in the vector multiplet, the amplitude/Wilson loop duality is inevitably broken at two loops.

Perturbative computation of string one-loop corrections to Wilson loop minimal surfaces in AdS{sub 5}×S{sup 5}

Energy Technology Data Exchange (ETDEWEB)

Forini, V. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof,Zum Großen Windkanal 6, 12489 Berlin (Germany); Tseytlin, A.A. [Theoretical Physics Group, Blackett Laboratory, Imperial College,London, SW7 2AZ (United Kingdom); Vescovi, E. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof,Zum Großen Windkanal 6, 12489 Berlin (Germany); Institute of Physics, University of São Paulo,Rua do Matão 1371, 05508-090 São Paulo (Brazil)

2017-03-01

We revisit the computation of the 1-loop string correction to the “latitude' minimal surface in AdS{sub 5}×S{sup 5} representing 1/4 BPS Wilson loop in planar N=4 SYM theory previously addressed in https://arxiv.org/abs/1512.00841 and https://arxiv.org/abs/1601.04708. We resolve the problem of matching with the subleading term in the strong coupling expansion of the exact gauge theory result (derived previously from localization) using a different method to compute determinants of 2d string fluctuation operators. We apply perturbation theory in a small parameter (angle of the latitude) corresponding to an expansion near the AdS{sub 2} minimal surface representing 1/2 BPS circular Wilson loop. This allows us to compute the corrections to the heat kernels and zeta-functions of the operators in terms of the known heat kernels on AdS{sub 2}. We apply the same method also to two other examples of Wilson loop surfaces: generalized cusp and k-wound circle.

Comments on correlation functions of large spin operators and null polygonal Wilson loops

Energy Technology Data Exchange (ETDEWEB)

Cardona, Carlos A., E-mail: cargicar@iafe.uba.ar [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA), C.C. 67 - Suc. 28, 1428 Buenos Aires (Argentina); Physics Department, University of Buenos Aires, CONICET, Ciudad Universitaria, 1428 Buenos Aires (Argentina)

2013-02-11

We discuss the relation between correlation functions of twist-two large spin operators and expectation values of Wilson loops along light-like trajectories. After presenting some heuristic field theoretical arguments suggesting this relation, we compute the divergent part of the correlator in the limit of large 't Hooft coupling and large spins, using a semi-classical world-sheet which asymptotically looks like a GKP rotating string. We show this diverges as expected from the expectation value of a null Wilson loop, namely, as (ln{mu}{sup -2}){sup 2}, {mu} being a cut-off of the theory.

Comments on correlation functions of large spin operators and null polygonal Wilson loops

International Nuclear Information System (INIS)

Cardona, Carlos A.

2013-01-01

We discuss the relation between correlation functions of twist-two large spin operators and expectation values of Wilson loops along light-like trajectories. After presenting some heuristic field theoretical arguments suggesting this relation, we compute the divergent part of the correlator in the limit of large 't Hooft coupling and large spins, using a semi-classical world-sheet which asymptotically looks like a GKP rotating string. We show this diverges as expected from the expectation value of a null Wilson loop, namely, as (lnμ −2 ) 2 , μ being a cut-off of the theory.

Wilson loops and its correlators with chiral operators in N = 2, 4 SCFT at large N

Science.gov (United States)

Sysoeva, E.

2018-03-01

In this paper we compute the vacuum expectation value of the Wilson loop and its correlators with chiral primary operators in N = 2, 4 superconformal U( N ) gauge theories at large N . After localization these quantities can be computed in terms of a deformed U( N ) matrix model. The Wilson loops we deal with are in the fundamental and symmetric representations.

New results on the 3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Bluemlein, Johannes; Freitas, Abilio de; Wissbrock, Fabian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hasselhuhn, Alexander [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, Sebastian [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Physik E

2013-01-02

We report on recent results obtained for the 3-loop heavy flavor Wilson coefficients in deepinelastic scattering (DIS) at general values of the Mellin variable N at larger scales of Q{sup 2}. These concern contributions to the gluonic ladder-topologies, the transition matrix elements in the variable flavor scheme of O(n{sub f}T{sup 2}{sub F}) and O(T{sup 2}{sub F}), and first results on higher 3-loop topologies. The knowledge of the heavy flavor Wilson coefficients at 3-loop order is of importance to extract the parton distribution functions and {alpha}{sub s}(M{sup 2}{sub Z}) in complete NNLO QCD analyses of the world precision data on the structure function F{sub 2}(x,Q{sup 2}).

Circular Wilson loops in defect conformal field theory

Energy Technology Data Exchange (ETDEWEB)

Aguilera-Damia, Jeremías; Correa, Diego H. [Instituto de Física La Plata, CONICET, Universidad Nacional de La Plata,C.C. 67, 1900 La Plata (Argentina); Giraldo-Rivera, Victor I. [International Centre for Theoretical Sciences (ICTS-TIFR),Shivakote, Hesaraghatta Hobli, Bengaluru 560089 (India)

2017-03-06

We study a D3-D5 system dual to a conformal field theory with a codimension-one defect that separates regions where the ranks of the gauge groups differ by k. With the help of this additional parameter, as observed by Nagasaki, Tanida and Yamaguchi, one can define a double scaling limit in which the quantum corrections are organized in powers of λ/k{sup 2}, which should allow to extrapolate results between weak and strong coupling regimes. In particular we consider a radius R circular Wilson loop placed at a distance L, whose internal space orientation is given by an angle χ. We compute its vacuum expectation value and show that, in the double scaling limit and for small χ and small L/R, weak coupling results can be extrapolated to the strong coupling limit.

Non-Abelian Stokes theorem for the Wilson loop operator in an arbitrary representation and its implication to quark confinement

Science.gov (United States)

Matsudo, Ryutaro; Kondo, Kei-Ichi

2015-12-01

We give a gauge-independent definition of magnetic monopoles in the S U (N ) Yang-Mills theory through the Wilson loop operator. For this purpose, we give an explicit proof of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the Wilson loop operator in an arbitrary representation of the S U (N ) gauge group to derive a new form for the non-Abelian Stokes theorem. The new form is used to extract the magnetic-monopole contribution to the Wilson loop operator in a gauge-invariant way, which enables us to discuss confinement of quarks in any representation from the viewpoint of the dual superconductor vacuum.

Wilson Loop and related strings for the instanton and their variational derivatives

International Nuclear Information System (INIS)

Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

1980-05-01

Ordered integrals along arcs (or circles) and segments for the instanton are computed. They are to obtain variational and partial derivatives for open an d closed strings. The D'Alembertian for wilson loops is also computed. (Author) [pt

Wilson loop, Regge trajectory and hadron masses in a Yang-Mills theory from semiclassical strings

International Nuclear Information System (INIS)

Bigazzi, F.; Cotrone, A.L.; Martucci, L.; Pando Zayas, L.A.

2004-07-01

We compute the one-loop string corrections to the Wilson loop, glueball Regge trajectory and stringy hadron masses in the Witten model of non supersymmetric, large-N Yang-Mills theory. The classical string configurations corresponding to the above field theory objects are respectively: open straight strings, folded closed spinning strings, and strings orbiting in the internal part of the supergravity background. For the rectangular Wilson loop we show that besides the standard Luscher term, string corrections provide a rescaling of the field theory string tension. The one-loop corrections to the linear glueball Regge trajectories render them nonlinear with a positive intercept, as in the experimental soft Pomeron trajectory. Strings orbiting in the internal space predict a spectrum of hadronic-like states charged under global flavor symmetries which falls in the same universality class of other confining models. (author)

String corrections to circular Wilson loop and anomalies

Science.gov (United States)

Cagnazzo, Alessandra; Medina-Rincon, Daniel; Zarembo, Konstantin

2018-02-01

We study string quantum corrections to the ratio of latitude and circular Wilson loops in N = 4 super-Yang-Mills theory at strong coupling. Conformal gauge for the corresponding minimal surface in AdS5 × S 5 is singular and we show that an IR anomaly associated with the divergence in the conformal factor removes previously reported discrepancy with the exact field-theory result. We also carefully check conformal anomaly cancellation and recalculate fluctuation determinants by directly evaluting phaseshifts for all the fluctuation modes.

Abelian Chern-Simons theory as the strong large-mass limit of topologically massive abelian gauge theory: the Wilson loop

International Nuclear Information System (INIS)

Giavarini, G.; Martin, C.P.; Ruiz Ruiz, F.

1993-01-01

We show that the renormalized vacuum expectation value of the Wilson loop for topologically massive abelian gauge theory in bbfR 3 can be defined so that its large-mass limit be the renormalized vaccum expectation value of the Wilson loop for abelian Chern-Simons theory also in bbfR 3 . (orig.)

Gravity duals of half-BPS Wilson loops

International Nuclear Information System (INIS)

D'Hoker, Eric; Estes, John; Gutperle, Michael

2007-01-01

We explicitly construct the fully back-reacted half-BPS solutions in Type IIB supergravity which are dual to Wilson loops with 16 supersymmetries in N = 4 super Yang-Mills. In a first part, we use the methods of a companion paper to derive the exact general solution of the half-BPS equations on the space AdS 2 x S 2 x S 4 x Σ, with isometry group SO(2, 1) x SO(3) x SO(5) in terms of two locally harmonic functions on a Riemann surface Σ with boundary. These solutions, generally, have varying dilaton and axion, and non-vanishing 3-form fluxes. In a second part, we impose regularity and topology conditions. These non-singular solutions may be parametrized by a genus g ≥ 0 hyperelliptic surface Σ, all of whose branch points lie on the real line. Each genus g solution has only a single asymptotic AdS 5 x S 5 region, but exhibits g homology 3-spheres, and an extra g homology 5-spheres, carrying respectively RR 3-form and RR 5-form charges. For genus 0, we recover AdS 5 x S 5 with 3 free parameters, while for genus g ≥ 1, the solution has 2g+5 free parameters. The genus 1 case is studied in detail. Numerical analysis is used to show that the solutions are regular throughout the g = 1 parameter space. Collapse of a branch cut on Σ subtending either a homology 3-sphere or a homology 5-sphere is non-singular and yields the genus g-1 solution. This behavior is precisely expected of a proper dual to a Wilson loop in gauge theory

ABJM Wilson loops in arbitrary representations

Energy Technology Data Exchange (ETDEWEB)

Hatsuda, Yasuyuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Honda, Masazumi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics

2013-06-15

We study vacuum expectation values (VEVs) of circular half BPS Wilson loops in arbitrary representations in ABJM theory. We find that those in hook representations are reduced to elementary integrations thanks to the Fermi gas formalism, which are accessible from the numerical studies similar to the partition function in the previous studies. For non-hook representations, we show that the VEVs in the grand canonical formalism can be exactly expressed as determinants of those in the hook representations. Using these facts, we can study the instanton effects of the VEVs in various representations. Our results are consistent with the worldsheet instanton effects studied from the topological string and a prescription to include the membrane instanton effects by shifting the chemical potential, which has been successful for the partition function.

ABJM Wilson loops in arbitrary representations

International Nuclear Information System (INIS)

Hatsuda, Yasuyuki; Moriyama, Sanefumi; Okuyama, Kazumi

2013-06-01

We study vacuum expectation values (VEVs) of circular half BPS Wilson loops in arbitrary representations in ABJM theory. We find that those in hook representations are reduced to elementary integrations thanks to the Fermi gas formalism, which are accessible from the numerical studies similar to the partition function in the previous studies. For non-hook representations, we show that the VEVs in the grand canonical formalism can be exactly expressed as determinants of those in the hook representations. Using these facts, we can study the instanton effects of the VEVs in various representations. Our results are consistent with the worldsheet instanton effects studied from the topological string and a prescription to include the membrane instanton effects by shifting the chemical potential, which has been successful for the partition function.

Infrared singularities of fermion propagator and their connection with the Wilson loop

International Nuclear Information System (INIS)

Sissakyan, A.N.; Skachkov, N.B.; Shevchenko, O.Yu.

1987-01-01

The factorization of infrared singularities of gauge-invariant spinor propagator is proved in the framework of QED. It turns out that this infrared factor coincides with the Wilson loop and accumulates all the dependence on the form of the path of the initial Green function

Recent progress on the calculation of three-loop heavy flavor Wilson coefficients in deep-inelastic scattering

International Nuclear Information System (INIS)

Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Behring, A.; Bluemlein, J.; Freitas, A. de; Raab, C.; Round, M.; Manteuffel, A. von

2014-07-01

We report on our latest results in the calculation of the three-loop heavy flavor contributions to the Wilson coefficients in deep-inelastic scattering in the asymptotic region Q 2 >>m 2 . We discuss the different methods used to compute the required operator matrix elements and the corresponding Feynman integrals. These methods very recently allowed us to obtain a series of new operator matrix elements and Wilson coefficients like the flavor non-singlet and pure singlet Wilson coefficients.

On the large N limit, Wilson Loops, Confinement and Composite Antisymmetric Tensor Field theories

CERN Document Server

Castro, C

2004-01-01

A novel approach to evaluate the Wilson loops asociated with a $ SU ( \\infty )$ gauge theory in terms of pure string degrees of freedom is presented. It is based on the Guendelman-Nissimov-Pacheva formulation of composite antisymmetric tensor field theories of area (volume ) preserving diffeomorphisms which admit $p$-brane solutions and which provide a $new$ route to scale symmetry breaking and confinement in Yang-Mills theory. The quantum effects are discussed and we evaluate the vacuum expectation values (vev) of the Wilson loops in the large $N$ limit of the $quenched$ reduced $SU(N)$ Yang-Mills theory in terms of a path integral involving pure string degrees of freedom. The $quenched$ approximation is necessary to avoid a crumpling of the string world-sheet giving rise to very large Hausdorff dimensions as pointed out by Olesen. The approach is also consistent with the recent results based on the AdS/CFT correspondence and dual QCD models (dual Higgs model with dual Dirac strings ). More general Loop wav...

Recent progress on the calculation of three-loop heavy flavor Wilson coefficients in deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Hasselhuhn, A.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Behring, A.; Bluemlein, J.; Freitas, A. de; Raab, C.; Round, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Wissbrock, F. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); IHES Institut des Hautes Etudes Scientifiques, Bures-sur-Yvette (France)

2014-07-15

We report on our latest results in the calculation of the three-loop heavy flavor contributions to the Wilson coefficients in deep-inelastic scattering in the asymptotic region Q{sup 2}>>m{sup 2}. We discuss the different methods used to compute the required operator matrix elements and the corresponding Feynman integrals. These methods very recently allowed us to obtain a series of new operator matrix elements and Wilson coefficients like the flavor non-singlet and pure singlet Wilson coefficients.

Influence of cusps and intersections on the Wilson loop in ν-dimensional space

International Nuclear Information System (INIS)

Bezerra, V.B.

1984-01-01

A discussion is given about the influence of cusps and intersections on the calculation of the Wilson loop in ν-dimensional space. In particular, for the two-dimensional case, it is shown that there are no divergences. (Author) [pt

3-loop contributions to heavy flavor Wilson coefficients of neutral and charged current DIS

International Nuclear Information System (INIS)

Hasselhuhn, Alexander

2013-11-01

In the present thesis several new contributions are made to achieve this goal. Different gauge-invariant subsets of graphs, i.e. whole color factors, are calculated, in order to break the ground for the systematic evaluation of new topologies and to develop corresponding computer algebra codes and computational algorithms to render a part of these problems. Furthermore, also some new results are obtained on the 2-loop level. The work focuses on the heavy quark corrections in the asymptotic region Q 2 >> m 2 , where the heavy flavor Wilson coefficients factorize into the light flavor Wilson coefficients and massive operator matrix elements. New contributions are obtained for the complete O(α s 3 n f T F 2 ) corrections to the operator matrix elements A gq,Q and A gg,Q . The computation of the Feynman integrals is performed using representations in generalized hypergeometric functions and finite sums. These sums are performed using modern symbolic summation methods implemented in the packages Sigma, Evaluate Multi Sums, and Sum Production. The results are renormalized and checked against Mellin moments. Furthermore, also the 2-loop corrections to the polarized massive OMEs ΔA gq,Q and ΔA gg,Q are calculated. Since the calculations are performed in dimensional regularization and Levi-Civita tensors are present in the diagrams, the OMEs are subject to a finite renormalization. New methods are developed to calculate genuine 3-loop topologies of ladder- and V-type, taking into account the number of heavy quark lines involved. The calculation methods involves mapping the Feynman parameterized representations onto multi-sums and using properties of Appell functions and other generalizations of hypergeometric functions. Two integrals are presented, for which the solution with summation methods remains yet an open problem. At three loops, for the first time also graphs with two distinct massive lines occur. A new method is presented for the calculation of such diagrams

Wilson loop OPE, analytic continuation and multi-Regge limit

International Nuclear Information System (INIS)

Hatsuda, Yasuyuki

2014-05-01

We explore a direct connection between the collinear limit and the multi-Regge limit for scattering amplitudes in the N=4 super Yang-Mills theory. Starting with the collinear expansion for the six-gluon amplitude in the Euclidean kinematic region, we perform an analytic continuation term by term to the so-called Mandelstam region. We find that the result coincides with the collinear expansion of the analytically continued amplitude. We then take the multi-Regge limit, and conjecture that the final result precisely reproduces the one from the BFKL approach. Combining this procedure with the OPE for null polygonal Wilson loops, we explicitly compute the leading contribution in the ''collinear-Regge'' limit up to five loops. Our results agree with all the known results up to four loops. At five-loop, our results up to the next-to-next-to-leading logarithmic approximation (NNLLA) also reproduce the known results, and for the N 3 LLA and the N 4 LLA give non-trivial predictions. We further present an all-loop prediction for the imaginary part of the next-to-double-leading logarithmic approximation. Our procedure has a possibility of an interpolation from weak to strong coupling in the multi-Regge limit with the help of the OPE.

Wilson loops in the Higgs phase of large N field theories on the conifold

International Nuclear Information System (INIS)

Caceres, E.; Hernandez, R.

2000-04-01

We study the quark-antiquark interaction in the large N limit of the superconformal field theory on D-3branes at a Calabi-Yau conical singularity. We compute the Wilson loop in the AdS 5 x T 11 supergravity background for the SU(2N) x SU(2N) theory. We also calculate the Wilson loop for the Higgs phase where the gauge group is broken to SU(N) x SU(N) x SU D (N). This corresponds to a two center configuration with some of the branes at the singularity and the rest of them at a smooth point. The calculation exhibits the expected Coulomb dependence for the interaction. The angular distribution of the BPS states is different than the one for a spherical horizon. (author)

The Wilson loop expectation values in 2-and 3-dimensional SU(2) LGT

International Nuclear Information System (INIS)

Li Zhibing; Zheng Weihong; Guo Shuohong

1989-01-01

An improved Monte Carlo scheme is applied to the computation of expectation values of nxm Wilson loops in both 2-and 3-dimensional SU(2) lattice gauge theories. The results are compared with those simulated by the discrete group Y 120 and the exact results in two dimensions

Recent results on the 3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, J.; Freitas A. de; Raab, C.; Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Ablinger, J.; Hasselhuhn, A.; Round, M.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Manteuffel, A. von [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Mainz Univ. (Germany). Inst. fuer Physik

2013-07-15

We report on recent progress in the calculation of the 3-loop massive Wilson coefficients in deep-inelastic scattering at general values of N for neutral and charged current reactions in the asymptotic region Q{sup 2}>>m{sup 2}.

Perturbative expansions from Monte Carlo simulations at weak coupling: Wilson loops and the static-quark self-energy

Science.gov (United States)

Trottier, H. D.; Shakespeare, N. H.; Lepage, G. P.; MacKenzie, P. B.

2002-05-01

Perturbative coefficients for Wilson loops and the static-quark self-energy are extracted from Monte Carlo simulations at weak coupling. The lattice volumes and couplings are chosen to ensure that the lattice momenta are all perturbative. Twisted boundary conditions are used to eliminate the effects of lattice zero modes and to suppress nonperturbative finite-volume effects due to Z(3) phases. Simulations of the Wilson gluon action are done with both periodic and twisted boundary conditions, and over a wide range of lattice volumes (from 34 to 164) and couplings (from β~9 to β~60). A high precision comparison is made between the simulation data and results from finite-volume lattice perturbation theory. The Monte Carlo results are shown to be in excellent agreement with perturbation theory through second order. New results for third-order coefficients for a number of Wilson loops and the static-quark self-energy are reported.

3-loop contributions to heavy flavor Wilson coefficients of neutral and charged current DIS

Energy Technology Data Exchange (ETDEWEB)

Hasselhuhn, Alexander

2013-11-15

In the present thesis several new contributions are made to achieve this goal. Different gauge-invariant subsets of graphs, i.e. whole color factors, are calculated, in order to break the ground for the systematic evaluation of new topologies and to develop corresponding computer algebra codes and computational algorithms to render a part of these problems. Furthermore, also some new results are obtained on the 2-loop level. The work focuses on the heavy quark corrections in the asymptotic region Q{sup 2} >> m{sup 2}, where the heavy flavor Wilson coefficients factorize into the light flavor Wilson coefficients and massive operator matrix elements. New contributions are obtained for the complete O({alpha}{sub s}{sup 3}n{sub f}T{sub F}{sup 2}) corrections to the operator matrix elements A{sub gq,Q} and A{sub gg,Q}. The computation of the Feynman integrals is performed using representations in generalized hypergeometric functions and finite sums. These sums are performed using modern symbolic summation methods implemented in the packages Sigma, Evaluate Multi Sums, and Sum Production. The results are renormalized and checked against Mellin moments. Furthermore, also the 2-loop corrections to the polarized massive OMEs {Delta}A{sub gq,Q} and {Delta}A{sub gg,Q} are calculated. Since the calculations are performed in dimensional regularization and Levi-Civita tensors are present in the diagrams, the OMEs are subject to a finite renormalization. New methods are developed to calculate genuine 3-loop topologies of ladder- and V-type, taking into account the number of heavy quark lines involved. The calculation methods involves mapping the Feynman parameterized representations onto multi-sums and using properties of Appell functions and other generalizations of hypergeometric functions. Two integrals are presented, for which the solution with summation methods remains yet an open problem. At three loops, for the first time also graphs with two distinct massive lines occur

Double-winding Wilson loops in SU(N) Yang-Mills theory - A criterion for testing the confinement models -

Science.gov (United States)

Matsudo, Ryutaro; Kondo, Kei-Ichi; Shibata, Akihiro

2018-03-01

We examine how the average of double-winding Wilson loops depends on the number of color N in the SU(N) Yang-Mills theory. In the case where the two loops C1 and C2 are identical, we derive the exact operator relation which relates the doublewinding Wilson loop operator in the fundamental representation to that in the higher dimensional representations depending on N. By taking the average of the relation, we find that the difference-of-areas law for the area law falloff recently claimed for N = 2 is excluded for N ⩾ 3, provided that the string tension obeys the Casimir scaling for the higher representations. In the case where the two loops are distinct, we argue that the area law follows a novel law (N - 3)A1/(N - 1) + A2 with A1 and A2(A1 law when (N ⩾ 3). Indeed, this behavior can be confirmed in the two-dimensional SU(N) Yang-Mills theory exactly.

Perturbative expansions from Monte Carlo simulations at weak coupling: Wilson loops and the static-quark self-energy

International Nuclear Information System (INIS)

Trottier, H.D.; Shakespeare, N.H.; Lepage, G.P.; Mackenzie, P.B.

2002-01-01

Perturbative coefficients for Wilson loops and the static-quark self-energy are extracted from Monte Carlo simulations at weak coupling. The lattice volumes and couplings are chosen to ensure that the lattice momenta are all perturbative. Twisted boundary conditions are used to eliminate the effects of lattice zero modes and to suppress nonperturbative finite-volume effects due to Z(3) phases. Simulations of the Wilson gluon action are done with both periodic and twisted boundary conditions, and over a wide range of lattice volumes (from 3 4 to 16 4 ) and couplings (from β≅9 to β≅60). A high precision comparison is made between the simulation data and results from finite-volume lattice perturbation theory. The Monte Carlo results are shown to be in excellent agreement with perturbation theory through second order. New results for third-order coefficients for a number of Wilson loops and the static-quark self-energy are reported

Wilson loops in heavy ion collisions and their calculation in AdS/CFT

CERN Document Server

Liu, H; Wiedemann, Urs Achim; Liu, Hong; Rajagopal, Krishna; Wiedemann, Urs Achim

2007-01-01

Expectation values of Wilson loops define the nonperturbative properties of the hot medium produced in heavy ion collisions that arise in the analysis of both radiative parton energy loss and quarkonium suppression. We use the AdS/CFT correspondence to calculate the expectation values of such Wilson loops in the strongly coupled plasma of N=4 super Yang-Mills (SYM) theory, allowing for the possibility that the plasma may be moving with some collective flow velocity as is the case in heavy ion collisions. We obtain the N=4 SYM values of the jet quenching parameter $\\hat q$, which describes the energy loss of a hard parton in QCD, and of the velocity-dependence of the quark-antiquark screening length for a moving dipole as a function of the angle between its velocity and its orientation. We show that if the quark-gluon plasma is flowing with velocity v_f at an angle theta with respect to the trajectory of a hard parton, the jet quenching parameter $\\hat q$ is modified by a factor gamma_f(1-v_f cos theta), and s...

Eigenvalue distributions of Wilson loops

International Nuclear Information System (INIS)

Lohmayer, Robert

2010-01-01

In the first part of this thesis, we focus on the distribution of the eigenvalues of the unitary Wilson loop matrix in the two-dimensional case at arbitrary finite N. To characterize the distribution of the eigenvalues, we introduce three density functions (the ''symmetric'', the ''antisymmetric'', and the ''true'' eigenvalue density) which differ at finite N but possess the same infinite-N limit, exhibiting the Durhuus-Olesen phase transition. Using expansions of determinants and inverse determinants in characters of totally symmetric or totally antisymmetric representations of SU(N), the densities at finite N can be expressed in terms of simple sums involving only dimensions and quadratic Casimir invariants of certain irreducible representations of SU(N), allowing for a numerical computation of the densities at arbitrary N to any desired accuracy. We find that the true eigenvalue density, adding N oscillations to the monotonic symmetric density, is in some sense intermediate between the symmetric and the antisymmetric density, which in turn is given by a sum of N delta peaks located at the zeros of the average of the characteristic polynomial. Furthermore, we show that the dependence on N can be made explicit by deriving integral representations for the resolvents associated to the three eigenvalue densities. Using saddle-point approximations, we confirm that all three densities reduce to the Durhuus-Olesen result in the infinite-N limit. In the second part, we study an exponential form of the multiplicative random complex matrix model introduced by Gudowska-Nowak et al. Varying a parameter which can be identified with the area of the Wilson loop in the unitary case, the region of non-vanishing eigenvalue density of the N-dimensional complex product matrix undergoes a topological change at a transition point in the infinite-N limit. We study the transition by a detailed analysis of the average of the modulus square of the characteristic polynomial. Furthermore

One-loop renormalisation for the second moment of GPDs with Wilson fermions

International Nuclear Information System (INIS)

Goeckeler, M.; Horsley, R.; Perlt, H.; Rakow, P.E.L.; Schaefer, A.; Schierholz, G.; Schiller, A.

2005-01-01

We calculate the non-forward quark matrix elements for operators with two covariant derivatives in one-loop lattice perturbation theory using Wilson fermions. These matrix elements are needed in the renormalisation of the second moment of generalised parton distributions measured in lattice QCD. For some commonly used representations of the hypercubic group we determine the sets of all mixing operators and find the matrices of mixing and renormalisation factors

Exact correlators on the Wilson loop in N=4 SYM: localization, defect CFT, and integrability

Science.gov (United States)

Giombi, Simone; Komatsu, Shota

2018-05-01

We compute a set of correlation functions of operator insertions on the 1 /8 BPS Wilson loop in N=4 SYM by employing supersymmetric localization, OPE and the Gram-Schmidt orthogonalization. These correlators exhibit a simple determinant structure, are position-independent and form a topological subsector, but depend nontrivially on the 't Hooft coupling and the rank of the gauge group. When applied to the 1 /2 BPS circular (or straight) Wilson loop, our results provide an infinite family of exact defect CFT data, including the structure constants of protected defect primaries of arbitrary length inserted on the loop. At strong coupling, we show precise agreement with a direct calculation using perturbation theory around the AdS2 string worldsheet. We also explain the connection of our results to the "generalized Bremsstrahlung functions" previously computed from integrability techniques, reproducing the known results in the planar limit as well as obtaining their finite N generalization. Furthermore, we show that the correlators at large N can be recast as simple integrals of products of polynomials (known as Q-functions) that appear in the Quantum Spectral Curve approach. This suggests an interesting interplay between localization, defect CFT and integrability.

Eigenvalue distributions of Wilson loops

Energy Technology Data Exchange (ETDEWEB)

Lohmayer, Robert

2010-07-01

In the first part of this thesis, we focus on the distribution of the eigenvalues of the unitary Wilson loop matrix in the two-dimensional case at arbitrary finite N. To characterize the distribution of the eigenvalues, we introduce three density functions (the ''symmetric'', the ''antisymmetric'', and the ''true'' eigenvalue density) which differ at finite N but possess the same infinite-N limit, exhibiting the Durhuus-Olesen phase transition. Using expansions of determinants and inverse determinants in characters of totally symmetric or totally antisymmetric representations of SU(N), the densities at finite N can be expressed in terms of simple sums involving only dimensions and quadratic Casimir invariants of certain irreducible representations of SU(N), allowing for a numerical computation of the densities at arbitrary N to any desired accuracy. We find that the true eigenvalue density, adding N oscillations to the monotonic symmetric density, is in some sense intermediate between the symmetric and the antisymmetric density, which in turn is given by a sum of N delta peaks located at the zeros of the average of the characteristic polynomial. Furthermore, we show that the dependence on N can be made explicit by deriving integral representations for the resolvents associated to the three eigenvalue densities. Using saddle-point approximations, we confirm that all three densities reduce to the Durhuus-Olesen result in the infinite-N limit. In the second part, we study an exponential form of the multiplicative random complex matrix model introduced by Gudowska-Nowak et al. Varying a parameter which can be identified with the area of the Wilson loop in the unitary case, the region of non-vanishing eigenvalue density of the N-dimensional complex product matrix undergoes a topological change at a transition point in the infinite-N limit. We study the transition by a detailed analysis of the average of the

Influence of cusps and intersections on the calculation of the Wilson loop in ν-dimensional space

International Nuclear Information System (INIS)

Bezerra, V.B.

1984-01-01

A discussion is given about the influence of cusps and intersections on the calculation of the Wilson Loop in ν-dimensional space. In particular, for the two-dimensional case, it is shown that there are no divergences. (Author) [pt

Light-like Wilson Loops and Cusp Anomalous Dimensions in Nonconformal Gauge Theories

International Nuclear Information System (INIS)

Pando Zayas, Leopoldo A.; Phalen, Daniel J.; Terrero-Escalante, Cesar A.

2008-01-01

We emphasize that nonconformal theories provide a natural playground for the ideas of the Maldacena conjecture opening the possibility of exploring properties that could potentially be in the same universality class as QCD. In particular, we discuss in detail how light-like Wilson loops, an important ingredient in the prescription for scattering amplitudes, can be described in a number of gravity duals of nonconformal gauge theories. We point out to a few universal properties and the prominent role of the strong scale

Correlator of fundamental and anti-symmetric Wilson loops in AdS/CFT correspondence

International Nuclear Information System (INIS)

Tai, T.-S.; Yamaguchi, Satoshi

2007-01-01

We study the two circular Wilson loop correlator in which one is of anti-symmetric representation, while the other is of fundamental representation in 4-dimensional N = 4 super Yang-Mills theory. This correlator has a good AdS dual, which is a system of a D5-brane and a fundamental string. We calculated the on-shell action of the string, and clarified the Gross-Ooguri transition in this correlator. Some limiting cases are also examined

Conical twist fields and null polygonal Wilson loops

Science.gov (United States)

Castro-Alvaredo, Olalla A.; Doyon, Benjamin; Fioravanti, Davide

2018-06-01

Using an extension of the concept of twist field in QFT to space-time (external) symmetries, we study conical twist fields in two-dimensional integrable QFT. These create conical singularities of arbitrary excess angle. We show that, upon appropriate identification between the excess angle and the number of sheets, they have the same conformal dimension as branch-point twist fields commonly used to represent partition functions on Riemann surfaces, and that both fields have closely related form factors. However, we show that conical twist fields are truly different from branch-point twist fields. They generate different operator product expansions (short distance expansions) and form factor expansions (large distance expansions). In fact, we verify in free field theories, by re-summing form factors, that the conical twist fields operator product expansions are correctly reproduced. We propose that conical twist fields are the correct fields in order to understand null polygonal Wilson loops/gluon scattering amplitudes of planar maximally supersymmetric Yang-Mills theory.

Double-winding Wilson loops in SU(N Yang-Mills theory – A criterion for testing the confinement models –

Directory of Open Access Journals (Sweden)

Matsudo Ryutaro

2018-01-01

Full Text Available We examine how the average of double-winding Wilson loops depends on the number of color N in the SU(N Yang-Mills theory. In the case where the two loops C1 and C2 are identical, we derive the exact operator relation which relates the doublewinding Wilson loop operator in the fundamental representation to that in the higher dimensional representations depending on N. By taking the average of the relation, we find that the difference-of-areas law for the area law falloff recently claimed for N = 2 is excluded for N ⩾ 3, provided that the string tension obeys the Casimir scaling for the higher representations. In the case where the two loops are distinct, we argue that the area law follows a novel law (N − 3A1/(N − 1 + A2 with A1 and A2(A1 < A2 being the minimal areas spanned respectively by the loops C1 and C2, which is neither sum-ofareas (A1 + A2 nor difference-of-areas (A2 − A1 law when (N ⩾ 3. Indeed, this behavior can be confirmed in the two-dimensional SU(N Yang-Mills theory exactly.

Symmetry breaking by Wilson loops in gauge field theory

International Nuclear Information System (INIS)

Dowker, J.S.; Jadhav, S.P.

1989-01-01

An analysis is presented of the gauge symmetry breaking caused by Wilson loops on a space-time whose spatial section is openR/sup d/ x S 3 /Γ, for all those fundamental groups Γ that give a homogeneous space. We concentrate on pure SU(3) and SU(5) gauge field theories and find that symmetry breaking can occur when d = 0, for all Γ. If d = 3, the extra minimal scalars prevent any breaking and one must include other fields to achieve this. Explicit forms for the vacuum energies are exhibited in the case of lens and prism spaces, the former for SU(n). For Γ = Z/sub m/, when m and the radius of the sphere become infinite, we recover the results on the space-time openR/sup d//sup +3/ x S 1

Monte Carlo calculation with unquenched Wilson-Fermions

International Nuclear Information System (INIS)

Montvay, I.

1984-01-01

A Monte Carlo updating procedure taking into account the virtual quark loops is described. It is based on high order hopping parameter expansion of the quark determinant for Wilson-fermions. In a first test run Wilson-loop expectation values are measured on 6 4 lattice at β=5.70 using 16sup(th) order hopping parameter expansion for the quark determinant. (orig.)

WiLE: A Mathematica package for weak coupling expansion of Wilson loops in ABJ(M) theory

Science.gov (United States)

Preti, M.

2018-06-01

We present WiLE, a Mathematica® package designed to perform the weak coupling expansion of any Wilson loop in ABJ(M) theory at arbitrary perturbative order. For a given set of fields on the loop and internal vertices, the package displays all the possible Feynman diagrams and their integral representations. The user can also choose to exclude non planar diagrams, tadpoles and self-energies. Through the use of interactive input windows, the package should be easily accessible to users with little or no previous experience. The package manual provides some pedagogical examples and the computation of all ladder diagrams at three-loop relevant for the cusp anomalous dimension in ABJ(M). The latter application gives also support to some recent results computed in different contexts.

Interacting open Wilson lines from noncommutative field theories

International Nuclear Information System (INIS)

Kiem, Youngjai; Lee, Sangmin; Rey, Soo-Jong; Sato, Haru-Tada

2002-01-01

In noncommutative field theories, it is known that the one-loop effective action describes the propagation of noninteracting open Wilson lines, obeying the flying dipole's relation. We show that the two-loop effective action describes the cubic interaction among 'closed string' states created by open Wilson line operators. Taking d-dimensional λ[Φ 3 ] * theory as the simplest setup, we compute the nonplanar contribution at a low-energy and large noncommutativity limit. We find that the contribution is expressible in a remarkably simple cubic interaction involving scalar open Wilson lines only and nothing else. We show that the interaction is purely geometrical and noncommutative in nature, depending only on the size of each open Wilson line

Wilson loops in 3-dimensional N = 6 supersymmetric Chern-Simons theory and their string theory duals

International Nuclear Information System (INIS)

Drukker, Nadav; Plefka, Jan; Young, Donovan

2008-01-01

We study Wilson loops in the three-dimensional N = 6 supersymmetric Chern-Simons theory recently constructed by Aharony, Bergman, Jafferis and Maldacena, that is conjectured to be dual to type IIA string theory on AdS 4 x CP 3 . We construct loop operators in the Chern-Simons theory which preserve 1/6 of the supercharges and calculate their expectation value up to 2-loop order at weak coupling. The expectation value at strong coupling is found by constructing the string theory duals of these operators. For low dimensional representations these are fundamental strings, for high dimensional representations these are D2-branes and D6-branes. In support of this identification we demonstrate that these string theory solutions match the symmetries, charges and the preserved supersymmetries of their Chern-Simons theory counterparts.

Parton densities in quantum chromodynamics gauge invariance, path-dependence and Wilson lines

CERN Document Server

Cherednikov, Igor O

2016-01-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and loops in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), ab initio techniques are developed and practical tools for their implementation presented. An emphasis is put on their renormalization and on implications on processes observable at experimental facilities.

Wilson lines in quantum field theory

CERN Document Server

Cherednikov, Igor O; Veken, Frederik F van der

2014-01-01

The objective of this book is to get the reader acquainted with theoretical and mathematical foundations of the concept of Wilson loops in the context of modern quantum field theory. It teaches how to perform independently with some elementary calculations on Wilson lines, and shows the recent development of the subject in different important areas of research.

Mirror symmetry and loop operators

Energy Technology Data Exchange (ETDEWEB)

Assel, Benjamin [Department of Mathematics, King’s College London,The Strand, London WC2R 2LS (United Kingdom); Gomis, Jaume [Perimeter Institute for Theoretical Physics,Waterloo, Ontario, N2L 2Y5 (Canada)

2015-11-09

Wilson loops in gauge theories pose a fundamental challenge for dualities. Wilson loops are labeled by a representation of the gauge group and should map under duality to loop operators labeled by the same data, yet generically, dual theories have completely different gauge groups. In this paper we resolve this conundrum for three dimensional mirror symmetry. We show that Wilson loops are exchanged under mirror symmetry with Vortex loop operators, whose microscopic definition in terms of a supersymmetric quantum mechanics coupled to the theory encode in a non-trivial way a representation of the original gauge group, despite that the gauge groups of mirror theories can be radically different. Our predictions for the mirror map, which we derive guided by branes in string theory, are confirmed by the computation of the exact expectation value of Wilson and Vortex loop operators on the three-sphere.

Baryon Wilson loop area law in QCD

International Nuclear Information System (INIS)

Cornwall, J.M.

1996-01-01

There is still confusion about the correct form of the area law for the baryonic Wilson loop (BWL) of QCD. Strong-coupling (i.e., finite lattice spacing in lattice gauge theory) approximations suggest the form exp[-KA Y ], where K is the q bar q string tension and A Y is the global minimum area, generically a three-bladed area with the blades joined along a Steiner line (Y configuration). However, the correct answer is exp[-(K/2)(A 12 +A 13 +A 23 )], where, e.g., A 12 is the minimal area between quark lines 1 and 2 (Δ configuration). This second answer was given long ago, based on certain approximations, and is also strongly favored in lattice computations. In the present work, we derive the Δ law from the usual vortex-monopole picture of confinement, and show that, in any case, because of the 1/2 in the Δ law, this law leads to a larger value for the BWL (smaller exponent) than does the Y law. We show that the three-bladed, strong-coupling surfaces, which are infinitesimally thick in the limit of zero lattice spacing, survive as surfaces to be used in the non-Abelian Stokes close-quote theorem for the BWL, which we derive, and lead via this Stokes close-quote theorem to the correct Δ law. Finally, we extend these considerations, including perturbative contributions, to gauge groups SU(N), with N>3. copyright 1996 The American Physical Society

Relativistic corrections to the static energy in terms of Wilson loops at weak coupling

Energy Technology Data Exchange (ETDEWEB)

Peset, Clara [Technische Universitaet Muenchen, Physik Department T31, Garching (Germany); Pineda, Antonio [Universitat Autonoma de Barcelona, Grup de Fisica Teorica, Dept. Fisica y IFAE-BIST, Barcelona (Spain); Stahlhofen, Maximilian [Johannes Gutenberg University, PRISMA Cluster of Excellence, Institute of Physics, Mainz (Germany)

2017-10-15

We consider the O(1/m) and the spin-independent momentum-dependent O(1/m{sup 2}) quasi-static energies of heavy quarkonium (with unequal masses). They are defined nonperturbatively in terms of Wilson loops. We determine their short-distance behavior through O(α{sup 3}) and O(α{sup 2}), respectively. In particular, we calculate the ultrasoft contributions to the quasi-static energies, which requires the resummation of potential interactions. Our results can be directly compared to lattice simulations. In addition, we also compare the available lattice data with the expectations from effective string models for the long-distance behavior of the quasi-static energies. (orig.)

A new scheme for the running coupling constant in gauge theories using Wilson loops

Energy Technology Data Exchange (ETDEWEB)

Kurachi, Masafumi [Los Alamos National Laboratory; Bilgici, Erek [AUSTRIA; Flachi, Antonion [KYOTO UNIV; Itou, Etsuko [KOGAKUIN UNIV; David Lin, C J [NATIONAL CHIAO-TUNG UNIV; Matsufuru, Hideo [KEK; Ohki, Hiroshi [KYOTO UNIV; Onogi, Tetsuya [KYOTO UNIV; Yamazaki, Takeshi [UNIV OF TSUKUBA

2009-01-01

We propose a new renormalization scheme of the running coupling constant in general gauge theories defined by using the Wilson loops. The renormalized coupling constant is obtained from the Cretz ratio in lattice simulations and the corresponding perturbative coefficient at the leading order. The latter calculation is performed by adopting the zeta-function resummation techniques. We make a benchmark test of our scheme in quenched QCD with the plaquette gauge action. The running of the coupling constant is determined by applying the step scaling procedure. Using several methods to improve the statistical accuracy, we show that the running coupling constant can be determined in a wide range of energy scales with relatively small number of gauge configurations.

Skein relations and Wilson loops in Chern-Simons gauge theory

International Nuclear Information System (INIS)

Horne, J.H.

1990-01-01

We derive the skein relations for the fundamental representations of SO(N), Sp(2n), SU(mvertical stroken), and OSp(mvertical stroke2n). These relations can be used recursively to calculate the expectation values of Wilson lines in three-dimensional Chern-Simons gauge theory with these gauge groups. A combination of braiding and tying of Wilson lines completely describes the skein relations. (orig.)

High-loop perturbative renormalization constants for Lattice QCD (III): three-loop quark currents for Iwasaki gauge action and n{sub f} = 4 Wilson fermions

Energy Technology Data Exchange (ETDEWEB)

Brambilla, M.; Di Renzo, F. [Universita di Parma (Italy); INFN, Gruppo Collegato di Parma, Dipartimento di Fisica e Scienze della Terra, Parma (Italy); Hasegawa, M. [Universita di Parma (Italy); Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation); INFN, Gruppo Collegato di Parma, Dipartimento di Fisica e Scienze della Terra, Parma (Italy)

2014-07-15

This is the third of a series of papers on three-loop computation of renormalization constants for Lattice QCD. Our main points of interest are results for the regularization defined by the Iwasaki gauge action and n{sub f} Wilson fermions. Our results for quark bilinears renormalized according to the RI'-MOM scheme can be compared to non-perturbative results. The latter are available for twisted mass QCD: being defined in the chiral limit, the renormalization constants must be the same. We also address more general problems. In particular, we discuss a few methodological issues connected to summing the perturbative series such as the effectiveness of boosted perturbation theory and the disentanglement of irrelevant and finite-volume contributions. Discussing these issues we consider not only the new results of this paper, but also those for the regularization defined by the tree-level Symanzik improved gauge action and n{sub f} Wilson fermions, which we presented in a recent paper of ours. We finally comment on the extent to which the techniques we put at work in the NSPT context can provide a fresher look into the lattice version of the RI'-MOM scheme. (orig.)

Variational solution of the loop equation in QCD

International Nuclear Information System (INIS)

Agishtein, M.E.; Migdal, A.A.

1988-01-01

A new technique for the large N loop equation of QCD is worked out. The Wilson loop W(C) is approximated by a Gaussian functional. The parameters are fitted to the loop equation, after which the equation is statisfied up to 0.2%. The resulting Wilson loop corresponds to linearly rising Regge trajectories. The problem of tachyon is still present, but it could be cured by iteration of the loop equation starting from this variational solution. (orig.)

Variational solution of the loop equation in QCD

International Nuclear Information System (INIS)

Agishtein, M.E.; Migdal, A.A.

1988-01-01

A new technique for the large N loop equation of QCD is worked out. The Wilson loop W(C) is approximated by a Gaussian functional. The parameters are fitted to the loop equation, after which the equation is satisfied up to 0.2%. The resulting Wilson loop corresponds to linearly rising Regge trajectories. The problem of tachyon is still present, but it could be cured by iteration of the loop equation starting from this variational solution

Three loop anomalous dimensions of higher moments of the non-singlet twist-2 Wilson and transversity operators in the M-bar S-bar and RI' schemes

International Nuclear Information System (INIS)

Gracey, John A.

2006-01-01

We compute the anomalous dimension of the third and fourth moments of the flavour non-singlet twist-2 Wilson and transversity operators at three loops in both the M-bar S-bar and RI' schemes. To assist with the extraction of estimates of matrix elements computed using lattice regularization, the finite parts of the Green's function where the operator is inserted in a quark 2-point function are also provided at three loops in both schemes

Wilson lines in quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Cherednikov, Igor Olegovich [Antwerpen Univ., Antwerp (Belgium). Fysica Dept.; Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Mertens, Tom; Veken, Frederik F. van der [Antwerpen Univ., Antwerp (Belgium). Fysica Dept.

2014-07-01

Wilson lines (also known as gauge links or eikonal lines) can be introduced in any gauge field theory. Although the concept of the Wilson exponentials finds an enormously wide range of applications in a variety of branches of modern quantum field theory, from condensed matter and lattice simulations to quantum chromodynamics, high-energy effective theories and gravity, there are surprisingly few books or textbooks on the market which contain comprehensive pedagogical introduction and consecutive exposition of the subject. The objective of this book is to get the potential reader acquainted with theoretical and mathematical foundations of the concept of the Wilson loops in the context of modern quantum field theory, to teach him/her to perform independently some elementary calculations with Wilson lines, and to familiarize him/her with the recent development of the subject in different important areas of research. The target audience of the book consists of graduate and postgraduate students working in various areas of quantum field theory, as well as researchers from other fields.

Wilson lines in quantum field theory

International Nuclear Information System (INIS)

Cherednikov, Igor Olegovich; Joint Institute of Nuclear Research, Moscow; Mertens, Tom; Veken, Frederik F. van der

2014-01-01

Wilson lines (also known as gauge links or eikonal lines) can be introduced in any gauge field theory. Although the concept of the Wilson exponentials finds an enormously wide range of applications in a variety of branches of modern quantum field theory, from condensed matter and lattice simulations to quantum chromodynamics, high-energy effective theories and gravity, there are surprisingly few books or textbooks on the market which contain comprehensive pedagogical introduction and consecutive exposition of the subject. The objective of this book is to get the potential reader acquainted with theoretical and mathematical foundations of the concept of the Wilson loops in the context of modern quantum field theory, to teach him/her to perform independently some elementary calculations with Wilson lines, and to familiarize him/her with the recent development of the subject in different important areas of research. The target audience of the book consists of graduate and postgraduate students working in various areas of quantum field theory, as well as researchers from other fields.

Functional Fourier transforms and the loop equation

International Nuclear Information System (INIS)

Bershadskii, M.A.; Vaisburd, I.D.; Migdal, A.A.

1986-01-01

The Migdal-Makeenko momentum-space loop equation is investigated. This equation is derived from the ordinary loop equation by taking the Fourier transform of the Wilson functional. A perturbation theory is constructed for the new equation and it is proved that the action of the loop operator is determined by vertex functions which coincide with those of the previous equation. It is shown how the ghost loop arises in direct iterations of the momentum-space equation with respect to the coupling constant. A simple example is used to illustrate the mechanism of appearance of an integration in the interior loops in transition to observables

Precision calculation of 1/4-BPS Wilson loops in AdS{sub 5}×S{sup 5}

Energy Technology Data Exchange (ETDEWEB)

Forini, V. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof, Zum Großen Windkanal 6, 12489 Berlin (Germany); Puletti, V. Giangreco M. [Science Institute, University of Iceland,Dunhaga 3, 107 Reykjavik (Iceland); Griguolo, L. [Dipartimento di Fisica e Scienze della Terra, Università di Parma andINFN Gruppo Collegato di Parma,Viale G.P. Usberti 7/A, 43100 Parma (Italy); Seminara, D. [Dipartimento di Fisica, Università di Firenze and INFN Sezione di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Vescovi, E. [Institut für Physik, Humboldt-Universität zu Berlin, IRIS Adlershof, Zum Großen Windkanal 6, 12489 Berlin (Germany)

2016-02-16

We study the strong coupling behaviour of 1/4-BPS circular Wilson loops (a family of “latitudes') in N=4 Super Yang-Mills theory, computing the one-loop corrections to the relevant classical string solutions in AdS{sub 5}×S{sup 5}. Supersymmetric localization provides an exact result that, in the large ’t Hooft coupling limit, should be reproduced by the sigma-model approach. To avoid ambiguities due to the absolute normalization of the string partition function, we compare the ratio between the generic latitude and the maximal 1/2-BPS circle: any measure-related ambiguity should simply cancel in this way. We use the Gel’fand-Yaglom method with Dirichlet boundary conditions to calculate the relevant functional determinants, that present some complications with respect to the standard circular case. After a careful numerical evaluation of our final expression we still find disagreement with the localization answer: the difference is encoded into a precise “remainder function'. We comment on the possible origin and resolution of this discordance.

Gluon quasidistribution function at one loop

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei; Zhao, Shuai [Shanghai Jiao Tong University, INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai (China); Zhu, Ruilin [Shanghai Jiao Tong University, INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai (China); Nanjing Normal University, Department of Physics and Institute of Theoretical Physics, Nanjing, Jiangsu (China)

2018-02-15

We study the unpolarized gluon quasidistribution function in the nucleon at one loop level in the large momentum effective theory. For the quark quasidistribution, power law ultraviolet divergences arise in the cut-off scheme and an important observation is that they all are subjected to Wilson lines. However for the gluon quasidistribution function, we first point out that the linear ultraviolet divergences also exist in the real diagram which is not connected to any Wilson line. We then study the one loop corrections to parton distribution functions in both cut-off scheme and dimensional regularization to deal with the ultraviolet divergences. In addition to the ordinary quark and gluon distributions, we also include the quark to gluon and gluon to quark splitting diagrams. The complete one-loop matching factors between the quasi and light cone parton distribution functions are presented in the cut-off scheme. We derive the P{sup z} evolution equation for quasi parton distribution functions, and find that the P{sup z} evolution kernels are identical to the DGLAP evolution kernels. (orig.)

Anticommuting variables, internal degrees of freedom, and the Wilson loop

International Nuclear Information System (INIS)

Barducci, A.; Casalbuoni, R.; Lusanna, L.

1981-01-01

In this paper we show that is possible to give a real physical meaning to theories in which internal degrees of freedom are described by Grassmann variables. The physical theory is defined by means of an averaging procedure in terms of a distribution function in the Grassmann restricted space satisfying all the physical requirements. If we use this result for a scalar particle with inner degrees of freedom (electric charge, colour, ...) interacting with Yang-Mills gauge fields, it turns out that we can define two different classical theories. Taking the average of the coupled particle-field equations of motion, we recover the usual classical theory. Taking instead the average of the solution of such equations we get a theory which is free from all the classical infinities (and so of the causal defects, like runaway solution or pre-acceleration) but also of all the effects of the same order in the charges (like radiation). The main point is that the processes of averaging and integrating the equations of motion do not commute. Then for the case of colour degrees of freedom we study the quantization of the theory by the path-integral method and we show that the functional integration can be done for an arbitrary gluon field simply by using the classical solution. As a result we obtain an expression for the Wilson loop as a functional integral for the internal fermionic degrees of freedom. (orig.)

Wilson-loop symmetry breaking reexamined

International Nuclear Information System (INIS)

Nakamura, A.; Shiraishi, K.

1988-07-01

The splitting in the energy of gauge field vacua on non-simply connected space S 3 /Z 2 is reconsidered. We show the calculation to the one-loop level for a Yang-Mills vector with a ghost field. We confirm our previous result and give a solution to the question offered by Freire, Romao and Barroso. (author)

Wilson loops from multicentre and rotating branes, mass gaps and phase structure in gauge theories

CERN Document Server

Brandhuber, A.

1999-01-01

Within the AdS/CFT correspondence we use multicentre D3-brane metrics to investigate Wilson loops and compute the associated heavy quark-antiquark potentials for the strongly coupled SU(N) super-Yang-Mills gauge theory, when the gauge symmetry is broken by the expectation values of the scalar fields. For the case of a uniform distribution of D3-branes over a disc, we find that there exists a maximum separation beyond which there is no force between the quark and the antiquark, i.e. the screening is complete. We associate this phenomenon with the possible existence of a mass gap in the strongly coupled gauge theory. In the finite-temperature case, when the corresponding supergravity solution is a rotating D3-brane solution, there is a class of potentials interpolating between a Coulombic and a confining behaviour. However, above a certain critical value of the mass parameter, the potentials exhibit a behaviour characteristic of statistical systems undergoing phase transitions. The physical path preserves the c...

IUE observations of the evolution of Comet Wilson (1986l) - comparison with P/Halley

International Nuclear Information System (INIS)

Roettger, E.E.; Feldman, P.D.; A'hearn, M.F.; Festou, M.C.; Mcfadden, L.A.

1989-01-01

IUE observations of Comet Wilson from September 1986 to November 1987, through perihelion, allow a comparison to be conducted between this 'new' comet and the highly evolved P/Halley, at comparable heliocentric distances. The temporal decreases of both OH and dust in Comet Wilson near perihelion were monotonic and slow, by contrast to Comet Halley's rapid fluctuations. Despite these differences, relative gas abundances were similar within a factor of about 2 for comparable heliocentric and geocentric distances; this indicates that P/Halley's in situ gas measurements may be typical of comets generally. 33 refs

Three loop massive operator matrix elements and asymptotic Wilson coefficients with two different masses

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.

Loop equations and bootstrap methods in the lattice

Directory of Open Access Journals (Sweden)

Peter D. Anderson

2017-08-01

Full Text Available Pure gauge theories can be formulated in terms of Wilson Loops by means of the loop equation. In the large-N limit this equation closes in the expectation value of single loops. In particular, using the lattice as a regulator, it becomes a well defined equation for a discrete set of loops. In this paper we study different numerical approaches to solving this equation. Previous ideas gave good results in the strong coupling region. Here we propose an alternative method based on the observation that certain matrices ρˆ of Wilson loop expectation values are positive definite. They also have unit trace (ρˆ⪰0,Trρˆ=1, in fact they can be defined as reduced density matrices in the space of open loops after tracing over color indices and can be used to define an entropy associated with the loss of information due to such trace SWL=−Tr[ρˆln⁡ρˆ]. The condition that such matrices are positive definite allows us to study the weak coupling region which is relevant for the continuum limit. In the exactly solvable case of two dimensions this approach gives very good results by considering just a few loops. In four dimensions it gives good results in the weak coupling region and therefore is complementary to the strong coupling expansion. We compare the results with standard Monte Carlo simulations.

On the loop-loop scattering amplitudes in Abelian and non-Abelian gauge theories

International Nuclear Information System (INIS)

Meggiolaro, Enrico

2005-01-01

The high-energy elastic scattering amplitude of two colour-singlet qq-bar pairs is governed by the correlation function of two Wilson loops, which follow the classical straight lines for quark (antiquark) trajectories. This quantity is expected to be free of IR divergences, differently from what happens for the parton-parton elastic scattering amplitude, described, in the high-energy limit, by the expectation value of two Wilson lines. We shall explicitly test this IR finiteness by a direct non-perturbative computation of the loop-loop scattering amplitudes in the (pedagogic, but surely physically interesting) case of quenched QED. The results obtained for the Abelian case will be generalized to the case of a non-Abelian gauge theory with Nc colours, but stopping to the order O(g4) in perturbation theory. In connection with the above-mentioned IR finiteness, we shall also discuss some analytic properties of the loop-loop scattering amplitudes in both Abelian and non-Abelian gauge theories, when going from Minkowskian to Euclidean theory, which can be relevant to the still unsolved problem of the s-dependence of hadron-hadron total cross-sections

Three loop massive operator matrix elements and asymptotic Wilson coefficients with two different masses

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.

Open Wilson lines and generalized star product in noncommutative scalar field theories

International Nuclear Information System (INIS)

Kiem, Youngjai; Sato, Haru-Tada; Rey, Soo-Jong; Yee, Jung-Tay

2002-01-01

Open Wilson line operators and a generalized star product have been studied extensively in noncommutative gauge theories. We show that they also show up in noncommutative scalar field theories as universal structures. We first point out that the dipole picture of noncommutative geometry provides an intuitive argument for the robustness of the open Wilson lines and generalized star products therein. We calculate the one-loop effective action of noncommutative scalar field theory with a cubic self-interaction and show explicitly that the generalized star products arise in the nonplanar part. It is shown that, at the low-energy, large noncommutativity limit, the nonplanar part is expressible solely in terms of the scalar open Wilson line operator and descendants

Loop-space quantum formulation of free electromagnetism

International Nuclear Information System (INIS)

Di Bartolo, C.; Nori, F.; Gambini, R.; Trias, A.

1983-01-01

A procedure for direct quantization of free electromagnetism in the loop-space is proposed. Explicit solutions for the loop-dependent vacuum and the Wilson loop-average are given. It is shown that elementary lines of magnetic field appear as extremals in the vacuum state as a result of the regularization procedure

Gauge theory loop operators and Liouville theory

International Nuclear Information System (INIS)

Drukker, Nadav; Teschner, Joerg

2009-10-01

We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S 4 - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)

Exponentiation for products of Wilson lines within the generating function approach

International Nuclear Information System (INIS)

Vladimirov, A.A.

2015-01-01

We present the generating function approach to the perturbative exponentiation of correlators of a product of Wilson lines and loops. The exponentiated expression is presented in closed form as an algebraic function of correlators of known operators, which can be seen as a generating function for web diagrams. The expression is naturally split onto two parts: the exponentiation kernel, which accumulates all non-trivial information about web diagrams, and the defect of exponentiation, which reconstructs the matrix exponent and is a function of the exponentiation kernel. The detailed comparison of the presented approach with existing approaches to exponentiation is presented as well. We also give examples of calculations within the generating function exponentiation, namely, we consider different configurations of light-like Wilson lines in the multi-gluon-exchange-webs (MGEW) approximation. Within this approximation the corresponding correlators can be calculated exactly at any order of perturbative expansion by only algebraic manipulations. The MGEW approximation shows violation of the dipole formula for infrared singularities at three-loop order.

Compact lattice QED with Wilson fermions

International Nuclear Information System (INIS)

Hoferichter, A.

1994-08-01

We study the phase structure and the chiral limit of 4d compact lattice QED with Wilson fermions (both dynamical and quenched). We use the standard Wilson gauge action and also a modified one suppressing lattice artifacts. Different techniques and observables to locate the chiral limit are discussed. (orig.)

Loop quantization as a continuum limit

International Nuclear Information System (INIS)

Manrique, Elisa; Oeckl, Robert; Weber, Axel; Zapata, Jose A

2006-01-01

We present an implementation of Wilson's renormalization group and a continuum limit tailored for loop quantization. The dynamics of loop-quantized theories is constructed as a continuum limit of the dynamics of effective theories. After presenting the general formalism we show as a first explicit example the 2D Ising field theory, an interacting relativistic quantum field theory with local degrees of freedom quantized by loop quantization techniques

Gauge theory loop operators and Liouville theory

Energy Technology Data Exchange (ETDEWEB)

Drukker, Nadav [Humboldt Univ. Berlin (Germany). Inst. fuer Physik; Gomis, Jaume; Okuda, Takuda [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Teschner, Joerg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2009-10-15

We propose a correspondence between loop operators in a family of four dimensional N=2 gauge theories on S{sup 4} - including Wilson, 't Hooft and dyonic operators - and Liouville theory loop operators on a Riemann surface. This extends the beautiful relation between the partition function of these N=2 gauge theories and Liouville correlators found by Alday, Gaiotto and Tachikawa. We show that the computation of these Liouville correlators with the insertion of a Liouville loop operator reproduces Pestun's formula capturing the expectation value of a Wilson loop operator in the corresponding gauge theory. We prove that our definition of Liouville loop operators is invariant under modular transformations, which given our correspondence, implies the conjectured action of S-duality on the gauge theory loop operators. Our computations in Liouville theory make an explicit prediction for the exact expectation value of 't Hooft and dyonic loop operators in these N=2 gauge theories. The Liouville loop operators are also found to admit a simple geometric interpretation within quantum Teichmueller theory as the quantum operators representing the length of geodesics. We study the algebra of Liouville loop operators and show that it gives evidence for our proposal as well as providing definite predictions for the operator product expansion of loop operators in gauge theory. (orig.)

Bootstrapping the Three-Loop Hexagon

Energy Technology Data Exchange (ETDEWEB)

Dixon, Lance J.; /CERN /SLAC; Drummond, James M.; /CERN /Annecy, LAPTH; Henn, Johannes M.; /Humboldt U., Berlin /Santa Barbara, KITP

2011-11-08

We consider the hexagonal Wilson loop dual to the six-point MHV amplitude in planar N = 4 super Yang-Mills theory. We apply constraints from the operator product expansion in the near-collinear limit to the symbol of the remainder function at three loops. Using these constraints, and assuming a natural ansatz for the symbol's entries, we determine the symbol up to just two undetermined constants. In the multi-Regge limit, both constants drop out from the symbol, enabling us to make a non-trivial confirmation of the BFKL prediction for the leading-log approximation. This result provides a strong consistency check of both our ansatz for the symbol and the duality between Wilson loops and MHV amplitudes. Furthermore, we predict the form of the full three-loop remainder function in the multi-Regge limit, beyond the leading-log approximation, up to a few constants representing terms not detected by the symbol. Our results confirm an all-loop prediction for the real part of the remainder function in multi-Regge 3 {yields} 3 scattering. In the multi-Regge limit, our result for the remainder function can be expressed entirely in terms of classical polylogarithms. For generic six-point kinematics other functions are required.

Improved quasi parton distribution through Wilson line renormalization

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiunn-Wei [Department of Physics, Center for Theoretical Sciences, and Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei, 106, Taiwan (China); Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ji, Xiangdong [INPAC, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240 (China); Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, MD 20742 (United States); Zhang, Jian-Hui, E-mail: jianhui.zhang@physik.uni-regensburg.de [Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg (Germany)

2017-02-15

Recent developments showed that hadron light-cone parton distributions could be directly extracted from spacelike correlators, known as quasi parton distributions, in the large hadron momentum limit. Unlike the normal light-cone parton distribution, a quasi parton distribution contains ultraviolet (UV) power divergence associated with the Wilson line self energy. We show that to all orders in the coupling expansion, the power divergence can be removed by a “mass” counterterm in the auxiliary z-field formalism, in the same way as the renormalization of power divergence for an open Wilson line. After adding this counterterm, the quasi quark distribution is improved such that it contains at most logarithmic divergences. Based on a simple version of discretized gauge action, we present the one-loop matching kernel between the improved non-singlet quasi quark distribution with a lattice regulator and the corresponding quark distribution in dimensional regularization.

Improved quasi parton distribution through Wilson line renormalization

Directory of Open Access Journals (Sweden)

Jiunn-Wei Chen

2017-02-01

Full Text Available Recent developments showed that hadron light-cone parton distributions could be directly extracted from spacelike correlators, known as quasi parton distributions, in the large hadron momentum limit. Unlike the normal light-cone parton distribution, a quasi parton distribution contains ultraviolet (UV power divergence associated with the Wilson line self energy. We show that to all orders in the coupling expansion, the power divergence can be removed by a “mass” counterterm in the auxiliary z-field formalism, in the same way as the renormalization of power divergence for an open Wilson line. After adding this counterterm, the quasi quark distribution is improved such that it contains at most logarithmic divergences. Based on a simple version of discretized gauge action, we present the one-loop matching kernel between the improved non-singlet quasi quark distribution with a lattice regulator and the corresponding quark distribution in dimensional regularization.

Cooling Active Region Loops Observed With SXT and TRACE

OpenAIRE

Winebarger, Amy R.; Warren, Harry P.

2005-01-01

An Impulsive Heating Multiple Strand (IHMS) Model is able to reproduce the observational characteristics of EUV (~ 1 MK) active region loops. This model implies that some of the loops must reach temperatures where X-ray filters are sensitive (> 2.5 MK) before they cool to EUV temperatures. Hence, some bright EUV loops must be preceded by bright X-ray loops. Previous analysis of X-ray and EUV active region observations, however, have concluded that EUV loops are not preceded by X-ray loops. In...

Wilson-Polyakov loops for critical strings and superstrings at finite temperature

International Nuclear Information System (INIS)

Green, M.B.

1992-01-01

An open string with end-points fixed at spatial separation L is a string theory analogue of the static quark-antiquark system in quenched QCD. Folowing a review of the quantum mechanics of this system in critical bosonic string theory the partition function at finite β (the inverse temperature) for fixed end-point open strings is discussed. This is related by a conformal transformation ('world-sheet duality') to the correlation function of two closed strings fixed at distinct spatial points (a string theory analogue of two Wilson-Polyakov loops). Temperature duality (β → β' = 4π 2 /β) relates this correlation function, in turn, to the finite-temperature Green function for a closed strong propagating between initial and final states that are at distinct (euclidean) space-time points. In addition, spatial duality relates the fixed end-point open string to the familiar open string with free end-points. A generalization to fixed end-points superstrings is suggested, in which the superalgebra may be viewed as the spatial dual of the usual open-string superalgebra. At zero temperature world-sheet duality relates the partition function of supersymmetric fixed end-point open strings to the correlation function of point-like closed-string states. These couple to combinations of the scalar and pseudoscalar states of a type-2b superstring superfield. At finite temperature supersymmetry is broken and this correlation function involves the propagation of non-supersymmetric states with non-zero winding numbers (which formally include a tachyon at temperatures above the Hagedorn transition). Temperature duality again relates the partition function to the finite-temperature Green function describing the propagator for point-like closed-string states of the dual theory, in which supersymmetry is broken. The singularity that arises in the critical bosonic theory as L is reduced below L = 2 π√α' is absent in the superstring and the static potential is well defined for all

Loop quantum corrected Einstein Yang-Mills black holes

Science.gov (United States)

Protter, Mason; DeBenedictis, Andrew

2018-05-01

In this paper, we study the homogeneous interiors of black holes possessing SU(2) Yang-Mills fields subject to corrections inspired by loop quantum gravity. The systems studied possess both magnetic and induced electric Yang-Mills fields. We consider the system of equations both with and without Wilson loop corrections to the Yang-Mills potential. The structure of the Yang-Mills Hamiltonian, along with the restriction to homogeneity, allows for an anomaly-free effective quantization. In particular, we study the bounce which replaces the classical singularity and the behavior of the Yang-Mills fields in the quantum corrected interior, which possesses topology R ×S2 . Beyond the bounce, the magnitude of the Yang-Mills electric field asymptotically grows monotonically. This results in an ever-expanding R sector even though the two-sphere volume is asymptotically constant. The results are similar with and without Wilson loop corrections on the Yang-Mills potential.

AN EXPERIMENTAL ASSESSMENT OF THE PLATE HEAT EXCHANGER CHARACTERISTICS BY WILSON PLOT METHOD

Directory of Open Access Journals (Sweden)

Jan Opatřil

2016-10-01

Full Text Available An aim of this paper is suggestion of the evaluation method based on the experimental data and the Wilson plot method for the Plate Heat Exchangers (PHE. For the purpose of the project the new experimental loop was built for the testing of PHE to obtain the overhaul heat transfer coefficient and pressure drop between inlet and outlet of the fluid. The measurement were done for three different PHE with the performance range 30-100kW. The working fluid was water on both sides of the PHE. The differences are in number of pates as well as in extrusion profiles. The Wilson plot evaluation method was involved for the processing experimental data. To obtain more accurate correlations between the experimental data and theoretical results yield of the Wilson plot, the method was enhanced by the measured pressure drop involving. This approach could be useful for PHE designing software and for the manufacturing company.

On multivariate Wilson bases

DEFF Research Database (Denmark)

Bownik, Marcin; Jakobsen, Mads Sielemann; Lemvig, Jakob

2017-01-01

A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. In this paper we give an account of the construction of bimodular Wilson bases in higher dimensions from Gabor frames of redundancy two.......A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. In this paper we give an account of the construction of bimodular Wilson bases in higher dimensions from Gabor frames of redundancy two....

Samuel Alexander Kinnier Wilson. Wilson's disease, Queen Square and neurology.

Science.gov (United States)

Broussolle, E; Trocello, J-M; Woimant, F; Lachaux, A; Quinn, N

2013-12-01

This historical article describes the life and work of the British physician Samuel Alexander Kinnier Wilson (1878-1937), who was one of the world's greatest neurologists of the first half of the 20th century. Early in his career, Wilson spent one year in Paris in 1903 where he learned from Pierre-Marie at Bicêtre Hospital. He subsequently retained uninterrupted links with French neurology. He also visited in Leipzig the German anatomist Paul Flechsig. In 1904, Wilson returned to London, where he worked for the rest of his life at the National Hospital for the Paralysed and Epileptic (later the National Hospital for Nervous Diseases, and today the National Hospital for Neurology and Neurosurgery) in Queen Square, and also at Kings' College Hospital. He wrote on 'the old motor system and the new', on disorders of motility and muscle tone, on the epilepsies, on aphasia, apraxia, tics, and pathologic laughing and crying, and most importantly on Wilson's disease. The other objective of our paper is to commemorate the centenary of Wilson's most important work published in 1912 in Brain, and also in Revue Neurologique, on an illness newly recognized and characterized by him entitled "Progressive lenticular degeneration, a familial nervous disease associated with liver cirrhosis". He analyzed 12 clinical cases, four of whom he followed himself, but also four cases previously published by others and a further two that he considered in retrospect had the same disease as he was describing. The pathological profile combined necrotic damage in the lenticular nuclei of the brain and hepatic cirrhosis. This major original work is summarized and discussed in the present paper. Wilson not only delineated what was later called hepato-lenticular degeneration and Wilson's disease, but also introduced for the first time the terms extrapyramidal syndrome and extrapyramidal system, stressing the role of the basal ganglia in motility. The present historical work emphasizes the special

Coronal Loop Evolution Observed with AIA and Hi-C

Science.gov (United States)

Mulu-Moore, Fana; Winebarger, A.; Cirtain, J.; Kobayashi, K.; Korreck, K.; Golub, L.; Kuzin. S.; Walsh, R.; DeForest, C.; DePontieu, B.;

Wilson's disease: cranial MRI observations and clinical correlation

International Nuclear Information System (INIS)

Sinha, S.; Taly, A.B.; Prashanth, L.K.; Venugopal, K.S.; Arunodaya, G.R.; Swamy, H.S.; Ravishankar, S.; Vasudev, M.K.

2006-01-01

Study of MRI changes may be useful in diagnosis, prognosis and better understanding of the pathophysiology of Wilson's disease (WD). We aimed to describe and correlate the MRI abnormalities of the brain with clinical features in WD. MRI evaluation was carried out in 100 patients (57 males, 43 females; mean age 19.3±8.9 years) using standard protocols. All but 18 patients were on de-coppering agents. Their history, clinical manifestations and scores for severity of disease were noted. The mean duration of illness and treatment were 8.3±10.8 years and 7.5±7.1 years respectively. MRI of the brain was abnormal in all the 93 symptomatic patients. The most conspicuous observations were atrophy of the cerebrum (70%), brainstem (66%) and cerebellum (52%). Signal abnormalities were also noted: putamen (72%), caudate (61%), thalami (58%), midbrain (49%), pons (20%), cerebral white matter (25%), cortex (9%), medulla (12%) and cerebellum (10%). The characteristic T2-W globus pallidal hypointensity (34%), ''Face of giant panda'' sign (12%), T1-W striatal hyperintensity (6%), central pontine myelinosis (7%), and bright claustral sign (4%) were also detected. MRI changes correlated with disease severity scores (P<0.001) but did not correlate with the duration of illness. MRI changes were universal but diverse and involved almost all the structures of the brain in symptomatic patients. A fair correlation between MRI observations and various clinical features provides an explanation for the protean manifestations of the disease. (orig.)

MR of the liver in Wilson`s disease; MRT der Leber bei Morbus Wilson

Energy Technology Data Exchange (ETDEWEB)

Vogl, T.J. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Steiner, S. [Klinikum Grosshadern, Radiologische Klinik und Poliklinik, Univ. Muenchen (Germany); Hammerstingl, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany); Schwarz, S. [Klinikum Grosshadern, Neurologische Klinik, Univ. Muenchen (Germany); Kraft, E. [Klinikum Grosshadern, Neurologische Klinik, Univ. Muenchen (Germany); Weinzierl, M. [Klinikum Grosshadern, 2. Medizinische Klinik, Univ. Muenchen (Germany); Felix, R. [Strahlenklinik und Poliklinik, Universitaetsklinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

1994-01-01

To show that Wilson`s disease is one likely cause of multiple low-intensity nodules of the liver we obtained MR images in 16 patients with clinically and histopathologically confirmed Wilson`s disease. Corresponding to morphological changes MRI enabled the subdivision of the patients into two groups. Using a T{sub 2}-weighted spin-echo sequence (TR/TE=2000/45-90) liver parenchyma showed multiple tiny low-intensity-nodules surrounded by high-intensity septa in 10 out of 16 patients. 5 patients had also low-intensity nodules in T{sub 1}-weighted images (TR/TE=600/20). In patients of this group histopathology revealed liver cirrhosis (n=7) and fibrosis (n=2). Common feature of this patient group was marked inflammatory cell infiltration into fibrous septa, increase of copper concentration in liver parenchyma and distinct pathological changes of laboratory data. In the remaining 6 patients no pathological change of liver morphology was demonstrated by MRI corresponding to slight histopathological changes of parenchyma and normal laboratory data. As low-intensity nodules surrounded by high intensity septa can be demonstrated in patients with marked inflammatory infiltration of liver parenchyma MRI may help to define Wilson patients with poorer prognosis. In patients with low-intensity nodules of the liver and unknown cause of liver cirrhosis laboratory data and histopathology should be checked when searching for disorders of copper metabolism. (orig.) [Deutsch] Im Rahmen einer prospektiven Studie wurde die Leber bei 16 Patienten mit klinisch gesichertem Morbus Wilson magnetresonanztomographisch untersucht. Zum Einsatz kamen T{sub 1}- und T{sub 2}-gewichtete Spin-Echo-Sequenzen vor und nach Applikation von Gd-DTPA (0,1 mmol/kg KG). Anhand der MRT-Befunde konnten zwei unterschiedliche Patientenkollektive definiert werden. 10 Patienten wiesen in der T{sub 2}-gewichteten Sequenz hypointense Regeneratknoten auf und zeigten histopathologisch ausgepraegte Befunde einer

Observable Signatures of Energy Release in Braided Coronal Loops

Energy Technology Data Exchange (ETDEWEB)

Pontin, D. I. [University of Dundee, Nethergate, Dundee, DD1 4HN (United Kingdom); Janvier, M. [Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, F-91405, Orsay Cedex (France); Tiwari, S. K.; Winebarger, A. R.; Cirtain, J. W. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Galsgaard, K. [Niels Bohr Institute, Geological Museum Østervoldgade 5-7, DK-1350, Copenhagen K (Denmark)

2017-03-10

We examine the turbulent relaxation of solar coronal loops containing non-trivial field line braiding. Such field line tangling in the corona has long been postulated in the context of coronal heating models. We focus on the observational signatures of energy release in such braided magnetic structures using MHD simulations and forward modeling tools. The aim is to answer the following question: if energy release occurs in a coronal loop containing braided magnetic flux, should we expect a clearly observable signature in emissions? We demonstrate that the presence of braided magnetic field lines does not guarantee a braided appearance to the observed intensities. Observed intensities may—but need not necessarily—reveal the underlying braided nature of the magnetic field, depending on the degree and pattern of the field line tangling within the loop. However, in all cases considered, the evolution of the braided loop is accompanied by localized heating regions as the loop relaxes. Factors that may influence the observational signatures are discussed. Recent high-resolution observations from Hi-C have claimed the first direct evidence of braided magnetic fields in the corona. Here we show that both the Hi-C data and some of our simulations give the appearance of braiding at a range of scales.

HEATING OF FLARE LOOPS WITH OBSERVATIONALLY CONSTRAINED HEATING FUNCTIONS

Energy Technology Data Exchange (ETDEWEB)

Qiu Jiong; Liu Wenjuan; Longcope, Dana W. [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States)

2012-06-20

We analyze high-cadence high-resolution observations of a C3.2 flare obtained by AIA/SDO on 2010 August 1. The flare is a long-duration event with soft X-ray and EUV radiation lasting for over 4 hr. Analysis suggests that magnetic reconnection and formation of new loops continue for more than 2 hr. Furthermore, the UV 1600 Angstrom-Sign observations show that each of the individual pixels at the feet of flare loops is brightened instantaneously with a timescale of a few minutes, and decays over a much longer timescale of more than 30 minutes. We use these spatially resolved UV light curves during the rise phase to construct empirical heating functions for individual flare loops, and model heating of coronal plasmas in these loops. The total coronal radiation of these flare loops are compared with soft X-ray and EUV radiation fluxes measured by GOES and AIA. This study presents a method to observationally infer heating functions in numerous flare loops that are formed and heated sequentially by reconnection throughout the flare, and provides a very useful constraint to coronal heating models.

A John Wilson

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education. A John Wilson. Articles written in Resonance – Journal of Science Education. Volume 11 Issue 7 July 2006 pp 70-76 Classroom. Inverting Matrices Constructed from Roots of Unity · A John Wilson · More Details Fulltext PDF ...

Wilson loop invariants from WN conformal blocks

Directory of Open Access Journals (Sweden)

Oleg Alekseev

2015-12-01

Full Text Available Knot and link polynomials are topological invariants calculated from the expectation value of loop operators in topological field theories. In 3D Chern–Simons theory, these invariants can be found from crossing and braiding matrices of four-point conformal blocks of the boundary 2D CFT. We calculate crossing and braiding matrices for WN conformal blocks with one component in the fundamental representation and another component in a rectangular representation of SU(N, which can be used to obtain HOMFLY knot and link invariants for these cases. We also discuss how our approach can be generalized to invariants in higher-representations of WN algebra.

The Universal One-Loop Effective Action

CERN Document Server

Drozd, Aleksandra; Quevillon, Jérémie; You, Tevong

2016-01-01

We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.

The universal one-loop effective action

International Nuclear Information System (INIS)

Drozd, Aleksandra; Ellis, John; Quevillon, Jérémie; You, Tevong

2016-01-01

We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.

ON-SHELL IMPROVEMENT OF THE MASSIVE WILSON QUARK ACTION.

Energy Technology Data Exchange (ETDEWEB)

AOKI, S.; KAYABA, Y.; KURAMASHI, Y.; YAMADA, N.

2005-04-01

We review a relativistic approach to the heavy quark physics in lattice QCD by applying a relativistic O(a) improvement to the massive Wilson quark action on the lattice. After explaining how power corrections of m{sub Q}a can be avoided and remaining uncertainties are reduced to be of order (a{Lambda}{sub QCD}){sup 2}, we demonstrate a determination of four improvement coefficients in the action up to one-loop level in a mass dependent way. We also show a perturbative determination of mass dependent renormalization factors and O(a) improvement coefficients for the vector and axial vector currents. Some preliminary results of numerical simulations are also presented.

ANALYSIS AND MODELING OF TWO FLARE LOOPS OBSERVED BY AIA AND EIS

Energy Technology Data Exchange (ETDEWEB)

Li, Y.; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qiu, J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

2012-10-10

We analyze and model an M1.0 flare observed by SDO/AIA and Hinode/EIS to investigate how flare loops are heated and evolve subsequently. The flare is composed of two distinctive loop systems observed in extreme ultraviolet (EUV) images. The UV 1600 A emission at the feet of these loops exhibits a rapid rise, followed by enhanced emission in different EUV channels observed by the Atmospheric Imaging Assembly (AIA) and the EUV Imaging Spectrometer (EIS). Such behavior is indicative of impulsive energy deposit and the subsequent response in overlying coronal loops that evolve through different temperatures. Using the method we recently developed, we infer empirical heating functions from the rapid rise of the UV light curves for the two loop systems, respectively, treating them as two big loops with cross-sectional area of 5'' by 5'', and compute the plasma evolution in the loops using the EBTEL model. We compute the synthetic EUV light curves, which, with the limitation of the model, reasonably agree with observed light curves obtained in multiple AIA channels and EIS lines: they show the same evolution trend and their magnitudes are comparable by within a factor of two. Furthermore, we also compare the computed mean enthalpy flow velocity with the Doppler shift measurements by EIS during the decay phase of the two loops. Our results suggest that the two different loops with different heating functions as inferred from their footpoint UV emission, combined with their different lengths as measured from imaging observations, give rise to different coronal plasma evolution patterns captured both in the model and in observations.

[Jacqueline Wilson. Tracy Beakeri sari] / Krista Kivisalu

Index Scriptorium Estoniae

Kivisalu, Krista, 1968-

2016-01-01

Tutvustus: Wilson, Jacqueline. Tracy Beakeri lugu. [Tallinn] : Pegasus, 2015 ; Wilson, Jacqueline. Pühadeüllatus. [Tallinn] : Pegasus, c2015 ; Wilson, Jacqueline. Julgusmäng. [Tallinn] : Pegasus, c2015

Heating and dynamics of two flare loop systems observed by AIA and EIS

Energy Technology Data Exchange (ETDEWEB)

Li, Y.; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Qiu, J., E-mail: yingli@nju.edu.cn [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

2014-02-01

We investigate heating and evolution of flare loops in a C4.7 two-ribbon flare on 2011 February 13. From Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) imaging observations, we can identify two sets of loops. Hinode/EUV Imaging Spectrometer (EIS) spectroscopic observations reveal blueshifts at the feet of both sets of loops. The evolution and dynamics of the two sets are quite different. The first set of loops exhibits blueshifts for about 25 minutes followed by redshifts, while the second set shows stronger blueshifts, which are maintained for about one hour. The UV 1600 observation by AIA also shows that the feet of the second set of loops brighten twice. These suggest that continuous heating may be present in the second set of loops. We use spatially resolved UV light curves to infer heating rates in the few tens of individual loops comprising the two loop systems. With these heating rates, we then compute plasma evolution in these loops with the 'enthalpy-based thermal evolution of loops' model. The results show that, for the first set of loops, the synthetic EUV light curves from the model compare favorably with the observed light curves in six AIA channels and eight EIS spectral lines, and the computed mean enthalpy flow velocities also agree with the Doppler shift measurements by EIS. For the second set of loops modeled with twice-heating, there are some discrepancies between modeled and observed EUV light curves in low-temperature bands, and the model does not fully produce the prolonged blueshift signatures as observed. We discuss possible causes for the discrepancies.

Taking Charge: Walter Sydney Adams and the Mount Wilson Observatory

Science.gov (United States)

Brashear, R.

2004-12-01

The growing preeminence of American observational astronomy in the first half of the 20th century is a well-known story and much credit is given to George Ellery Hale and his skill as an observatory-building entrepreneur. But a key figure who has yet to be discussed in great detail is Walter Sydney Adams (1876-1956), Hale's Assistant Director at Mount Wilson Observatory. Due to Hale's illnesses, Adams was Acting Director for much of Hale's tenure, and he became the second Director of Mount Wilson from 1923 to 1946. Behind his New England reserve Adams was instrumental in the growth of Mount Wilson and thus American astronomy in general. Adams was hand-picked by Hale to take charge of stellar spectroscopy work at Yerkes and Mount Wilson and the younger astronomer showed tremendous loyalty to Hale and Hale's vision throughout his career. As Adams assumed the leadership role at Mount Wilson he concentrated on making the observatory a place where researchers worked with great freedom but maintain a high level of cooperation. This paper will concentrate on Adams's early years and look at his growing relationship with Hale and how he came to be the central figure in the early history of Mount Wilson as both a solar and stellar observatory. His education, his years at Dartmouth and Yerkes (including his unfortunate encounter with epsilon Leonis), and his formative years on Mount Wilson are all important in learning how he shaped the direction of Mount Wilson and the development of American astronomy in the first half of the 20th century. This latter history cannot be complete until we bring Adams into better focus.

Loop transfer recovery for general observer architecture

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Søgaard-Andersen, Per; Stoustrup, Jakob

1991-01-01

A general and concise formulation is given of the loop transfer recovery (LTR) design problem based on recovery errors. Three types of recovery errors are treated: open loop recovery, sensitivity recovery and input-output recovery errors. The three corresponding versions of the asymptotic recovery...... recovery cases. This general recovery formulation covers all known observer based compensator types as special cases. The conditions given in this setting are effectively the aim of all known LTR design methods. The recovery formulation is interpreted in terms of a modelmatching problem as well, which...... is examined by means of the Q-parametrization. It is shown how the general controller obtained by the Q-parametrization can be written as a Luenberger observer based controller. In all cases, n controller states suffice to achieve recovery. The compensators are characterized for errors both on the input...

FERMILAB: Bob Wilson 80

Energy Technology Data Exchange (ETDEWEB)

Anon.

1994-06-15

On March 4, an international symposium and tribute was held at Fermilab in honour of the Laboratory's founding director Robert Rathbun Wilson on the occasion of his 80th birthday. The symposium - 'Celebrating an Era of Courage and Creativity' - featured talks and reflections by many of Wilson's colleagues and friends including Fermilab Director John Peoples and Director Emeritus Leon Lederman.

New results on the 3-loop heavy flavor corrections in deep-inelastic scattering

Energy Technology Data Exchange (ETDEWEB)

Behring, A.; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron, Zeuthen (Germany); and others

2013-12-15

We report on recent progress in the calculation of the 3-loop massiveWilson coefficients in deep inelastic scattering at general values of N for neutral- and charged-current reactions in the asymptotic region Q{sup 2}>>m{sup 2}. Four new out of eight massive operator matrix elements and Wilson coefficients have been obtained recently. We also discuss recent results on Feynman graphs containing two massive fermion lines and present complete results for the bubble topologies for all processes.

Analytic continuation of the harmonic sums for the 3-loop anomalous dimensions

International Nuclear Information System (INIS)

Bluemlein, J.; Moch, S.O.

2005-03-01

We present for numerical use the analytic continuations to complex arguments of those basic Mellin transforms, which build the harmonic sums contributing to the 3-loop anomalous dimensions. Eight new basic functions contribute in addition to the analytic continuations for the 2-loop massless Wilson coefficients calculated previously. The representations derived have a relative accuracy of better than 10 -7 in the range x element of [10 -6 , 0.98]. (orig.)

HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

Energy Technology Data Exchange (ETDEWEB)

Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

2013-08-01

Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

FERMILAB: Bob Wilson 80

International Nuclear Information System (INIS)

Anon.

1994-01-01

On March 4, an international symposium and tribute was held at Fermilab in honour of the Laboratory's founding director Robert Rathbun Wilson on the occasion of his 80th birthday. The symposium - 'Celebrating an Era of Courage and Creativity' - featured talks and reflections by many of Wilson's colleagues and friends including Fermilab Director John Peoples and Director Emeritus Leon Lederman

OBSERVATIONAL SIGNATURES OF CORONAL LOOP HEATING AND COOLING DRIVEN BY FOOTPOINT SHUFFLING

Energy Technology Data Exchange (ETDEWEB)

Dahlburg, R. B.; Taylor, B. D. [LCP and FD, Naval Research Laboratory, Washington, DC 20375 (United States); Einaudi, G. [Berkeley Research Associates, Inc., Beltsville, MD 20705 (United States); Ugarte-Urra, I. [College of Science, George Mason University, Fairfax, VA 22030 (United States); Warren, H. P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Rappazzo, A. F. [Advanced Heliophysics, Pasadena, CA 91106 (United States); Velli, M., E-mail: rdahlbur@lcp.nrl.navy.mil [EPSS, UCLA, Los Angeles, CA 90095 (United States)

2016-01-20

The evolution of a coronal loop is studied by means of numerical simulations of the fully compressible three-dimensional magnetohydrodynamic equations using the HYPERION code. The footpoints of the loop magnetic field are advected by random motions. As a consequence, the magnetic field in the loop is energized and develops turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned current sheets: energy is deposited at small scales where heating occurs. Dissipation is nonuniformly distributed so that only a fraction of the coronal mass and volume gets heated at any time. Temperature and density are highly structured at scales that, in the solar corona, remain observationally unresolved: the plasma of our simulated loop is multithermal, where highly dynamical hotter and cooler plasma strands are scattered throughout the loop at sub-observational scales. Numerical simulations of coronal loops of 50,000 km length and axial magnetic field intensities ranging from 0.01 to 0.04 T are presented. To connect these simulations to observations, we use the computed number densities and temperatures to synthesize the intensities expected in emission lines typically observed with the Extreme Ultraviolet Imaging Spectrometer on Hinode. These intensities are used to compute differential emission measure distributions using the Monte Carlo Markov Chain code, which are very similar to those derived from observations of solar active regions. We conclude that coronal heating is found to be strongly intermittent in space and time, with only small portions of the coronal loop being heated: in fact, at any given time, most of the corona is cooling down.

The Asymptotic Expansion of Lattice Loop Integrals Around the Continuum Limit

International Nuclear Information System (INIS)

Becher, Thomas G

2002-01-01

We present a method of computing any one-loop integral in lattice perturbation theory by systematically expanding around its continuum limit. At any order in the expansion in the lattice spacing, the result can be written as a sum of continuum loop integrals in analytic regularization and a few genuine lattice integrals (''master integrals''). These lattice master integrals are independent of external momenta and masses and can be computed numerically. At the one-loop level, there are four master integrals in a theory with only bosonic fields, seven in HQET and sixteen in QED or QCD with Wilson fermions

The Universal Askey-Wilson Algebra

Directory of Open Access Journals (Sweden)

Paul Terwilliger

2011-07-01

Full Text Available In 1992 A. Zhedanov introduced the Askey-Wilson algebra AW=AW(3 and used it to describe the Askey-Wilson polynomials. In this paper we introduce a central extension Δ of AW, obtained from AW by reinterpreting certain parameters as central elements in the algebra. We call Δ the universal Askey-Wilson algebra. We give a faithful action of the modular group PSL_2(Z on Δ as a group of automorphisms. We give a linear basis for Δ. We describe the center of Δ and the 2-sided ideal Δ[Δ,Δ]Δ. We discuss how Δ is related to the q-Onsager algebra.

Wilson's disease: cranial MRI observations and clinical correlation

Energy Technology Data Exchange (ETDEWEB)

Sinha, S.; Taly, A.B.; Prashanth, L.K.; Venugopal, K.S.; Arunodaya, G.R.; Swamy, H.S. [National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neurology, Bangalore (India); Ravishankar, S.; Vasudev, M.K. [National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neuroimaging and Interventional Radiology, Bangalore (India)

2006-09-15

Study of MRI changes may be useful in diagnosis, prognosis and better understanding of the pathophysiology of Wilson's disease (WD). We aimed to describe and correlate the MRI abnormalities of the brain with clinical features in WD. MRI evaluation was carried out in 100 patients (57 males, 43 females; mean age 19.3{+-}8.9 years) using standard protocols. All but 18 patients were on de-coppering agents. Their history, clinical manifestations and scores for severity of disease were noted. The mean duration of illness and treatment were 8.3{+-}10.8 years and 7.5{+-}7.1 years respectively. MRI of the brain was abnormal in all the 93 symptomatic patients. The most conspicuous observations were atrophy of the cerebrum (70%), brainstem (66%) and cerebellum (52%). Signal abnormalities were also noted: putamen (72%), caudate (61%), thalami (58%), midbrain (49%), pons (20%), cerebral white matter (25%), cortex (9%), medulla (12%) and cerebellum (10%). The characteristic T2-W globus pallidal hypointensity (34%), ''Face of giant panda'' sign (12%), T1-W striatal hyperintensity (6%), central pontine myelinosis (7%), and bright claustral sign (4%) were also detected. MRI changes correlated with disease severity scores (P<0.001) but did not correlate with the duration of illness. MRI changes were universal but diverse and involved almost all the structures of the brain in symptomatic patients. A fair correlation between MRI observations and various clinical features provides an explanation for the protean manifestations of the disease. (orig.)

Search for Activity in Comet-Asteroid Transition Object 107P/Wilson-Harrington

Science.gov (United States)

Khayat, Alain; Meech, K.; Pittichova, J.; Schorghofer, N.; Yang, B.; Sonnett, S.; Riesen, T.; Kleyna, J.; Kaluna, H.; Keane, J.

2010-10-01

Comet-asteroid transition object 107P/Wilson-Harrington was observed near its October 22, 2009 perihelion passage to search for activity. No activity was detected. Consequently, we place limits on possible dust production of 0.013 kg/s at 1.23 AU. Furthermore, the data was not sufficient to constrain a rotation period; however, it is clear that the rotation period is > 4hr. Our data is consistent with the observations of others (6.1 hr). Phase function fitting yielded a value of the phase coefficient beta= 0.0406 ± .0001 mag/deg, similar to C-type asteroids that have a linear phase curve at large phase angles. Thermal models for 107P/Wilson-Harrington show that the average loss rate of exposed crystalline ice at zero latitude is in the order of 0.3 meters/year. The derived high loss rate suggests that 107P/Wilson-Harrington is deprived of surface ice. Our observations and analysis confirm earlier findings that 107P/Wilson-Harrington is an example of the very few such objects discovered so far. Such study we made is a critical next step in understanding the life of dormant comets, and a window into the evolutionary end states of the lives of comets that become extinct. This work has been supported in part by AST-0807521 from the National Science Foundation.

Cool transition region loops observed by the Interface Region Imaging Spectrograph

Science.gov (United States)

Huang, Z.; Xia, L.; Li, B.; Madjarska, M. S.

2015-12-01

An important class of loops in the solar atmosphere, cool transition region loops, have received little attention mainly due to instrumental limitations. We analyze a cluster of these loops in the on-disk active region NOAA 11934 recorded in a Si IV 1402.8 Å spectral raster and 1400Å slit-jaw (SJ) images taken by the Interface Region Imaging Spectrograph. We divide these loops into three groups and study their dynamics, evolution and interaction.The first group comprises geometrically relatively stable loops, which are finely scaled with 382~626 km cross-sections. Siphon flows in these loops are suggested by the Doppler velocities gradually changing from -10 km/s (blue-shifts) in one end to 20 km/s (red-shifts) in the other. Nonthermal velocities from 15 to 25 km/s were determined. The obtained physical properties suggest that these loops are impulsively heated by magnetic reconnection occurring at the blue-shifted footpoints where magnetic cancellation with a rate of 1015 Mx/s is found. The released magnetic energy is redistributed by the siphon flows. The second group corresponds to two active footpoints rooted in mixed-magnetic-polarity regions. Magnetic reconnection in both footpoints is suggested by explosive-event line profiles with enhanced wings up to 200 km/s and magnetic cancellation with a rate of ~1015 Mx/s. In the third group, an interaction between two cool loop systems is observed. Mixed-magnetic polarities are seen in their conjunction area where explosive-event line profiles and magnetic cancellation with a rate of 3×1015 Mx/s are found. This is a clear indication that magnetic reconnection occurs between these two loop systems. Our observations suggest that the cool transition region loops are heated impulsively most likely by sequences of magnetic reconnection events.

Spectrum of the Wilson Dirac operator at finite lattice spacings

DEFF Research Database (Denmark)

Akemann, G.; Damgaard, Poul Henrik; Splittorff, Kim

2011-01-01

We consider the effect of discretization errors on the microscopic spectrum of the Wilson Dirac operator using both chiral Perturbation Theory and chiral Random Matrix Theory. A graded chiral Lagrangian is used to evaluate the microscopic spectral density of the Hermitian Wilson Dirac operator...... as well as the distribution of the chirality over the real eigenvalues of the Wilson Dirac operator. It is shown that a chiral Random Matrix Theory for the Wilson Dirac operator reproduces the leading zero-momentum terms of Wilson chiral Perturbation Theory. All results are obtained for fixed index...... of the Wilson Dirac operator. The low-energy constants of Wilson chiral Perturbation theory are shown to be constrained by the Hermiticity properties of the Wilson Dirac operator....

SU(3) sextet model with Wilson fermions

DEFF Research Database (Denmark)

Hansen, Martin; Drach, Vincent; Pica, Claudio

2017-01-01

to be inside or very close to the lower boundary of the conformal window. We use the Wilson discretization for the fermions and map the phase structure of the lattice model. We study several spectral and gradient flow observables both in the bulk and the weak coupling phases. While in the bulk phase we find...

Procedural learning changes in patients with Wilson's disease

Institute of Scientific and Technical Information of China (English)

Yumei Jiang; Xiang Shen; Xiaoping Wang; Wenjie Li

2011-01-01

In the present study, we compared explicit memory performance, using the Wechsler Memory Scale, and implicit memory performance, using the Nissen software version of the serial reaction time task, in patients with Wilson's disease to normal controls. The Wilson's disease patients exhibited deficits in explicit memory tasks, such as figure recall and understanding memory. Moreover, the Wilson's disease patients exhibited deficits in implicit memory tasks, including significantly prolonged response times. These findings indicate that Wilson's disease patients have explicit and implicit partial memory impairments.

Structure and Dynamics of Cool Flare Loops Observed by the Interface Region Imaging Spectrograph

Energy Technology Data Exchange (ETDEWEB)

Mikuła, K.; Berlicki, A. [Astronomical Institute, University of Wrocław, Kopernika 11, 51–622 Wrocław (Poland); Heinzel, P.; Liu, W., E-mail: mikula@astro.uni.wroc.pl [Astronomical Institute, The Czech Academy of Sciences, 25165 Ondřejov (Czech Republic)

2017-08-10

Flare loops were well observed with the Interface Region Imaging Spectrograph ( IRIS ) during the gradual phase of two solar flares on 2014 March 29 and 2015 June 22. Cool flare loops are visible in various spectral lines formed at chromospheric and transition-region temperatures and exhibit large downflows which correspond to the standard scenario. The principal aim of this work is to analyze the structure and dynamics of cool flare loops observed in Mg ii lines. Synthetic profiles of the Mg ii h line are computed using the classical cloud model and assuming a uniform background intensity. In this paper, we study novel IRIS NUV observations of such loops in Mg ii h and k lines and also show the behavior of hotter lines detected in the FUV channel. We obtained the spatial evolution of the velocities: near the loop top, the flow velocities are small and they are increasing toward the loop legs. Moreover, from slit-jaw image (SJI) movies, we observe some plasma upflows into the loops, which are also detectable in Mg ii spectra. The brightness of the loops systematically decreases with increasing flow velocity, and we ascribe this to the effect of Doppler dimming, which works for Mg ii lines. Emission profiles of Mg ii were found to be extremely broad, and we explain this through the large unresolved non-thermal motions.

Chirally improving Wilson fermions I. O(a) improvement

International Nuclear Information System (INIS)

Frezzotti, R.; Rossi, G.C.

2004-01-01

We show that it is possible to improve the chiral behaviour and the approach to the continuum limit of correlation functions in lattice QCD with Wilson fermions by taking arithmetic averages of correlators computed in theories regularized with Wilson terms of opposite sign. Improved hadronic masses and matrix elements can be obtained by similarly averaging the corresponding physical quantities separately computed within the two regularizations. To deal with the problems related to the spectrum of the Wilson-Dirac operator, which are particularly worrisome when Wilson and mass terms are such as to give contributions of opposite sign to the real part of the eigenvalues, we propose to use twisted-mass lattice QCD for the actual computation of the quantities taking part to the averages. The choice ±π/2 for the twisting angle is particularly interesting, as O(a) improved estimates of physical quantities can be obtained even without averaging data from lattice formulations with opposite Wilson terms. In all cases little or no extra computing power is necessary, compared to simulations with standard Wilson fermions or twisted-mass lattice QCD. (author)

Observational constraints on loop quantum cosmology.

Science.gov (United States)

Bojowald, Martin; Calcagni, Gianluca; Tsujikawa, Shinji

2011-11-18

In the inflationary scenario of loop quantum cosmology in the presence of inverse-volume corrections, we give analytic formulas for the power spectra of scalar and tensor perturbations convenient to compare with observations. Since inverse-volume corrections can provide strong contributions to the running spectral indices, inclusion of terms higher than the second-order runnings in the power spectra is crucially important. Using the recent data of cosmic microwave background and other cosmological experiments, we place bounds on the quantum corrections.

Possible precursors of ball lightning. Observation of closed loops in high voltage discharges

International Nuclear Information System (INIS)

Alexeff, I.; Rader, M.

1995-01-01

Several hundred photographs of ultrahigh voltage discharges have been obtained that show closed current loops. These closed current loops may be precursors of ball lightning. One feature of these discharges may explain why observations of ball lightning may be infrequent; that is, there is a distinct threshold in voltage and/or current below which the closed loops do not occur. This threshold current fits other experimental data but is well above the usually observed currents in natural lightning. 10 refs., 3 figs

Phase structure and confinement properties of noncompact gauge theories: Z(N) Wilson loop and effective noncompact model

International Nuclear Information System (INIS)

Borisenko, O.A.; Petrov, V.K.; Zinovjev, G.M.; Bohacik, J.

1997-01-01

An approach to studying lattice gauge models in the weak-coupling region is proposed. Conceptually, this approach is based on the crucial role of original Z(N) symmetry and of the invariant gauge-group measure. As an example, an effective model from the compact Wilson formulation of SU(2) gauge theory is calculated in d=3 dimensions at zero temperature. The confining properties and the phase structure of the effective model are studied in detail

Olin C. Wilson (1909-1994)

Science.gov (United States)

Preston, George W.

1995-02-01

Congenial, fiercely independent, and firmly grounded in the virtues of experimental science, Olin Wilson was a canny practitioner of the art of the possible in observational astrophysics as it flourished in the middle of the 20th century. He enjoyed a long association with the Astronomical Society of the Pacific as a contributor to its Publications, as President of the Society, and as recipient of its Catherine Wolfe Bruce Medal. By the time he departed, stellar astrophysics had matured and had acquired new dimensions due to Olin's diligence and curiosity. (SECTION: Obituary)

Open Wilson lines as states of closed string

International Nuclear Information System (INIS)

Murakami, Koichi; Nakatsu, Toshio

2003-01-01

A system of a D-brane in bosonic string theory on a constant B field background is studied in order to obtain further insight into the bulk-boundary duality. Boundary states which describe arbitrary numbers of open-string tachyons and gluons are given. The UV behavior of field theories on the non-commutative world-volume is investigated by using these states. We take the zero-slope limits of the generating functions of one-loop amplitudes of gluons (and open-string tachyons) in which the region of the small open-string proper time is magnified. The existence of a B field allows the limits to be slightly different from the standard field theory limits of a closed-string. These limits enable us to obtained world-volume theories at a trans-string scale. In this limit the generating functions are shown to be factorized into two curved open Wilson lines (and their analogues) and become integrals on the space of paths with a Gaussian distribution around straight lines. These facts indicate the possibility that field theories on the non-commutative world-volume are topological at such a trans-string scale. We also give a proof of the Dhar-Kitazawa conjecture by determining an explicit correspondence between the closed-string states and the paths. Momentum eigenstates of closed-string or momentum loops also play an important role in these analyses. (author)

Monte Carlo simulation of Su(2) lattice gauge theory with internal quark loops

International Nuclear Information System (INIS)

Azcoiti, V.; Nakamura, A.

1982-01-01

Dynamical effects of quark loops in lattice gauge theory with icosahedral group are studied. The standard Wilson action is employed and the fermionic part by a discretize pseudo fermionic method is calculated. The masses of π, rho, ω are computed and the average value of an effective fermionic action is evaluated

Extensions of the Wilson-Bappu effect among very luminous stars

International Nuclear Information System (INIS)

Stencel, R.E.

1978-01-01

Wilson and Bappu (1957) published their observational correlation of Msub(v) and the logarithm of the full width at half maximum of the CaII K-line central emission for G, K and M stars. The accuracy makes the approach valuable for late-type supergiants since other methods suffer from comparable errors. However, for F through M supergiants (Ia, O), circumstellar absorption obscures the chromospheric K-line core emission and excludes such objects from the Wilson-Bappu correlation. The author reports on a new class of emission lines in late-type giant and supergiant spectra that exhibit Msub(v) correlated widths, yet are detectable among the brightest stars. (Auth.)

arXiv Wilson lines and UV sensitivity in magnetic compactifications

CERN Document Server

Ghilencea, D.M.

2017-06-07

We investigate the ultraviolet (UV) behaviour of 6D N=1 supersymmetric effective (Abelian) gauge theories compactified on a two-torus (T$_{2}$) with magnetic flux. To this purpose we compute offshell the one-loop correction to the Wilson line state self-energy. The offshell calculation is actually necessary to capture the usual effective field theory expansion in powers of (∂/Λ). Particular care is paid to the regularization of the (divergent) momentum integrals, which is relevant for identifying the corresponding counterterm(s). We find a counterterm which is a new higher dimensional effective operator of dimension d=6, that is enhanced for a larger compactification area (where the effective theory applies) and is consistent with the symmetries of the theory. Its consequences are briefly discussed and comparison is made with orbifold compactifications without flux.

Strong Wilson polygons from the lodge of free and bound mesons

Energy Technology Data Exchange (ETDEWEB)

Bonini, Alfredo; Fioravanti, Davide [Sezione INFN di Bologna, Dipartimento di Fisica e Astronomia, Università di Bologna,Via Irnerio 46, 40126 Bologna (Italy); Piscaglia, Simone [Dipartimento di Fisica and INFN, Università di Torino,Via P. Giuria 1, 10125 Torino (Italy); Rossi, Marco [Dipartimento di Fisica dell’Università della Calabria and INFN, Gruppo collegato di Cosenza,Arcavacata di Rende, 87036 Cosenza (Italy)

2016-04-05

Previously predicted by the S-matrix bootstrap of the excitations over the GKP quantum vacuum, the appearance of a new particle at strong coupling — formed by one fermion and one anti-fermion — is here confirmed: this two-dimensional meson shows up, along with its infinite tower of bound states, while analysing the fermionic contributions to the Operator Product Expansion (collinear regime) of the Wilson null polygon loop. Moreover, its existence, free and bound, turns out to be a powerful idea in re-summing all the contributions (at large coupling) for a general n-gon (n≥6) to a Thermodynamic Bethe Ansatz, which is proven to be equivalent to the known one and suggests new structures for a special Y-system.

X-ray studies of irradiation induced dislocation loops in metals

International Nuclear Information System (INIS)

Larson, B.C.

1975-01-01

Theoretical and experimental progress has resulted in the increased use of x-rays for the study of defects and defect clusters in crystals. An outline of the theoretical framework associated with Huang, Stokes-Wilson and integral diffuse scattering from dislocation loops is presented, and an account of recent experiments on radiation induced loops is given. These studies include low temperature, ambient temperature, and elevated temperature irradiations of metals with electrons, neutrons, and accelerated ions, and pertain to the study of the thermal annealing characteristics as well as the as-produced damage structure. The information obtained by x-rays as to the type, size and concentrations of dislocation loops is contrasted with existing electron microscopy, electrical resistivity, and lattice parameter data in order to establish correlations and identify areas of disagreement

The Observatory as Laboratory: Spectral Analysis at Mount Wilson Observatory

Science.gov (United States)

Brashear, Ronald

2018-01-01

This paper will discuss the seminal changes in astronomical research practices made at the Mount Wilson Observatory in the early twentieth century by George Ellery Hale and his staff. Hale’s desire to set the agenda for solar and stellar astronomical research is often described in terms of his new telescopes, primarily the solar tower observatories and the 60- and 100-inch telescopes on Mount Wilson. This paper will focus more on the ancillary but no less critical parts of Hale’s research mission: the establishment of associated “physical” laboratories as part of the observatory complex where observational spectral data could be quickly compared with spectra obtained using specialized laboratory equipment. Hale built a spectroscopic laboratory on the mountain and a more elaborate physical laboratory in Pasadena and staffed it with highly trained physicists, not classically trained astronomers. The success of Hale’s vision for an astronomical observatory quickly made the Carnegie Institution’s Mount Wilson Observatory one of the most important astrophysical research centers in the world.

The logarithmic contributions to the O(α{sub s}{sup 3}) asymptotic massive Wilson coefficients and operator matrix elements in deeply inelastic scattering

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.)

Wilson's disease: an analysis of 28 Brazilian children

Directory of Open Access Journals (Sweden)

Rodolpho Truffa Kleine

2012-01-01

Full Text Available OBJECTIVES: Clinical-laboratory and evolutionary analysis of twenty-eight patients with Wilson's disease. METHODS: Twenty-eight children (twelve females and sixteen males with Wilson's disease were evaluated retrospectively between 1987 and 2009, with a follow-up of 72 months (1 - 240 months. The clinical, laboratory, and histologic features at diagnosis were recorded at the end of the study. RESULTS: The median age at diagnosis was 11 years (2 - 18 years. Twelve patients were asymptomatic, seven had hepatitis symptoms, five had raised aminotransferase levels, three had hepatomegaly associated with neurological disorders, one had fulminant hepatitis with hemolytic anemia, and six patients presented with a Kayser-Fleischer ring. A histological analysis revealed that six children had chronic hepatitis, seven had cirrhosis, two had steatosis, one had portal fibrosis, and one had massive necrosis. The treatment consisted of D-penicillamine associated with pyridoxine for 26 patients. Adverse effects were observed in the other two patients: one presented with uncontrollable vomiting and the other demonstrated elastosis perforans serpiginosa. At the end of the study, all 26 treated patients were asymptomatic. Twenty-four of the patients were treated with D-penicillamine and pyridoxine, and two were treated with trientine and zinc sulfate. A liver transplant was performed in one patient with fulminant hepatitis, but the final patient died 48 hours after admission to the intensive care unit. CONCLUSIONS: Family screenings associated with early treatment are important in preventing Wilson's disease symptoms and potentially fatal disease progression. The study suggests that Wilson's disease must be ruled out in children older than two years presenting with abnormal levels of hepatic enzymes because of the heterogeneity of symptoms and the encouraging treatment results obtained so far.

Perturbative two- and three-loop coefficients from large β Monte Carlo

Science.gov (United States)

Lepage, G. P.; Mackenzie, P. B.; Shakespeare, N. H.; Trottier, H. D.

Perturbative coefficients for Wilson loops and the static quark self-energy are extracted from Monte Carlo simulations at large β on finite volumes, where all the lattice momenta are large. The Monte Carlo results are in excellent agreement with perturbation theory through second order. New results for third order coefficients are reported. Twisted boundary conditions are used to eliminate zero modes and to suppress Z3 tunneling.

Perturbative two- and three-loop coefficients from large b Monte Carlo

International Nuclear Information System (INIS)

Lepage, G.P.; Mackenzie, P.B.; Shakespeare, N.H.; Trottier, H.D.

1999-01-01

Perturbative coefficients for Wilson loops and the static quark self-energy are extracted from Monte Carlo simulations at large β on finite volumes, where all the lattice momenta are large. The Monte Carlo results are in excellent agreement with perturbation theory through second order. New results for third order coefficients are reported. Twisted boundary conditions are used to eliminate zero modes and to suppress Z 3 tunneling

Perturbative two- and three-loop coefficients from large β Monte Carlo

International Nuclear Information System (INIS)

Lepage, G.P.; Mackenzie, P.B.; Shakespeare, N.H.; Trottier, H.D.

2000-01-01

Perturbative coefficients for Wilson loops and the static quark self-energy are extracted from Monte Carlo simulations at large β on finite volumes, where all the lattice momenta are large. The Monte Carlo results are in excellent agreement with perturbation theory through second order. New results for third order coefficients are reported. Twisted boundary conditions are used to eliminate zero modes and to suppress Z 3 tunneling

Loop Evolution Observed with AIA and Hi-C

Science.gov (United States)

Mulu-Moore, Fana; Winebarger, Amy R.; Cirtain, Jonathan W.; Kobayashi, Ken; Korreck, Kelly E.; Golub, Leon; Kuzin, Sergei; Walsh, Robert William; DeForest, Craig E.; De Pontieu, Bart;

Independent SU(2)-loop variables and the reduced configuration space of SU(2)-lattice gauge theory

International Nuclear Information System (INIS)

Loll, R.

1992-01-01

We give a reduction procedure for SU(2)-trace variables and an explicit description of the reduced configuration sace of pure SU(2)-gauge theory on the hypercubic lattices in two, three and four dimensions, using an independent subset of the gauge-invariant Wilson loops. (orig.)

First Imaging Observation of Standing Slow Wave in Coronal Fan Loops

International Nuclear Information System (INIS)

Pant, V.; Tiwari, A.; Banerjee, D.; Yuan, D.

2017-01-01

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations are very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s"−"1. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.

First Imaging Observation of Standing Slow Wave in Coronal Fan Loops

Energy Technology Data Exchange (ETDEWEB)

Pant, V.; Tiwari, A.; Banerjee, D. [Indian Institute of Astrophysics, Bangalore 560 034 (India); Yuan, D. [Institute of Space Science and Applied Technology, Harbin Institute of Technology, Shenzhen 518000 (China)

2017-09-20

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves that were generated due to X-class flares in the distant active region AR 11429. To characterize the nature of oscillations, we created time–distance maps along the fan loops and noted that the intensity oscillations at two ends of the loops were out of phase. As we move along the fan loop, the amplitude of the oscillations first decreased and then increased. The out-of-phase nature together with the amplitude variation along the loop implies that these oscillations are very likely to be standing waves. The period of the oscillations is estimated to be ∼27 minutes, damping time to be ∼45 minutes, and phase velocity projected in the plane of sky to be ∼65–83 km s{sup −1}. The projected phase speeds were in the range of the acoustic speed of coronal plasma at about 0.6 MK, which further indicates that these are slow waves. To the best of our knowledge, this is the first report on the existence of the standing slow waves in non-flaring fan loops.

Iterative and iterative-noniterative integral solutions in 3-loop massive QCD calculations

International Nuclear Information System (INIS)

Ablinger, J.; Radu, C.S.; Schneider, C.; Behring, A.; Imamoglu, E.; Van Hoeij, M.; Von Manteuffel, A.; Raab, C.G.

2017-11-01

Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension γ (2) qg and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the ρ-parameter.

Iterative and iterative-noniterative integral solutions in 3-loop massive QCD calculations

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Radu, C.S.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Behring, A. [RWTH Aachen Univ. (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Imamoglu, E.; Van Hoeij, M. [Florida State Univ., Tallahassee, FL (United States). Dept. of Mathematics; Von Manteuffel, A. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Raab, C.G. [Johannes Kepler Univ., Linz (Austria). Inst. for Algebra

2017-11-15

Various of the single scale quantities in massless and massive QCD up to 3-loop order can be expressed by iterative integrals over certain classes of alphabets, from the harmonic polylogarithms to root-valued alphabets. Examples are the anomalous dimensions to 3-loop order, the massless Wilson coefficients and also different massive operator matrix elements. Starting at 3-loop order, however, also other letters appear in the case of massive operator matrix elements, the so called iterative non-iterative integrals, which are related to solutions based on complete elliptic integrals or any other special function with an integral representation that is definite but not a Volterra-type integral. After outlining the formalism leading to iterative non-iterative integrals,we present examples for both of these cases with the 3-loop anomalous dimension γ{sup (2)}{sub qg} and the structure of the principle solution in the iterative non-interative case of the 3-loop QCD corrections to the ρ-parameter.

Meson masses in electromagnetic fields with Wilson fermions

Science.gov (United States)

Bali, G. S.; Brandt, B. B.; Endrődi, G.; Gläßle, B.

2018-02-01

We determine the light meson spectrum in QCD in the presence of background magnetic fields using quenched Wilson fermions. Our continuum extrapolated results indicate a monotonous reduction of the connected neutral pion mass as the magnetic field grows. The vector meson mass is found to remain nonzero, a finding relevant for the conjectured ρ -meson condensation at strong magnetic fields. The continuum extrapolation was facilitated by adding a novel magnetic field-dependent improvement term to the additive quark mass renormalization. Without this term, sizable lattice artifacts that would deceptively indicate an unphysical rise of the connected neutral pion mass for strong magnetic fields are present. We also investigate the impact of these lattice artifacts on further observables like magnetic polarizabilities and discuss the magnetic field-induced mixing between ρ -mesons and pions. We also derive Ward-Takashi identities for QCD +QED both in the continuum formulation and for (order a -improved) Wilson fermions.

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.)

Perturbative two- and three-loop coefficients from large {beta} Monte Carlo

Energy Technology Data Exchange (ETDEWEB)

Lepage, G.P.; Mackenzie, P.B.; Shakespeare, N.H.; Trottier, H.D

2000-03-01

Perturbative coefficients for Wilson loops and the static quark self-energy are extracted from Monte Carlo simulations at large {beta} on finite volumes, where all the lattice momenta are large. The Monte Carlo results are in excellent agreement with perturbation theory through second order. New results for third order coefficients are reported. Twisted boundary conditions are used to eliminate zero modes and to suppress Z{sub 3} tunneling.

On Wilson bases in $L^2(\\mathbb{R}^d)$

DEFF Research Database (Denmark)

Bownik, Marcin; Sielemann Jakobsen, Mads; Lemvig, Jakob

2017-01-01

A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. It is well known that, starting from a tight Gabor frame for $L^{2}(\\mathbb{R})$ with redundancy 2, one can construct an orthonormal Wilson basis for $L^2(\\mathbb{R})$ whose...... of redundancy $2^k$, where $k=1, 2, \\hdots, d$. These results generalize most of the known results about the existence of orthonormal Wilson bases....

Three-loop corrections to the soft anomalous dimension in multileg scattering

CERN Document Server

Almelid, Øyvind; Gardi, Einan

2016-01-01

We present the three-loop result for the soft anomalous dimension governing long-distance singularities of multi-leg gauge-theory scattering amplitudes of massless partons. We compute all contributing webs involving semi-infinite Wilson lines at three loops and obtain the complete three-loop correction to the dipole formula. We find that non-dipole corrections appear already for three coloured partons, where the correction is a constant without kinematic dependence. Kinematic dependence appears only through conformally-invariant cross ratios for four coloured partons or more, and the result can be expressed in terms of single-valued harmonic polylogarithms of weight five. While the non-dipole three-loop term does not vanish in two-particle collinear limits, its contribution to the splitting amplitude anomalous dimension reduces to a constant, and it only depends on the colour charges of the collinear pair, thereby preserving strict collinear factorization properties. Finally we verify that our result is consi...

Lattice artifacts in the non-Abelian Debye screening mass in one-loop order

International Nuclear Information System (INIS)

Kaste, P.; Rothe, H.J.

1997-01-01

We compute the electric screening mass in lattice QCD with Wilson fermions at finite temperature and chemical potential to one-loop order, and show that lattice artifacts arising from a finite lattice spacing result in an enhancement of the screening mass as compared to the continuum. We discuss the magnitude of this enhancement as a function of the temperature and chemical potential for lattices with a different number of lattice sites in the temporal direction that can be implemented in lattice simulations. Most of the enhancement is found to be due to the fermion loop contribution. copyright 1997 The American Physical Society

Wilson's Disease Association International

Science.gov (United States)

... of Colorado and graduated with a B.S. in finance. Latest News & Announcements Search Our Site About WDA ... Help Donate Volunteer Shop Online Search the Internet Corporate Sponsorship Marketplace Copyright © 1978 - 2017 The Wilson Disease ...

Hepatocellular Carcinoma: An Unusual Complication of Longstanding Wilson Disease.

Science.gov (United States)

Gunjan, Deepak; Shalimar; Nadda, Neeti; Kedia, Saurabh; Nayak, Baibaswata; Paul, Shashi B; Gamanagatti, Shivanand Ramachandra; Acharya, Subrat K

2017-06-01

Wilson disease is caused by the accumulation of copper in the liver, brain or other organs, due to the mutation in ATP7B gene, which encodes protein that helps in excretion of copper in the bile canaliculus. Clinical presentation varies from asymptomatic elevation of transaminases to cirrhosis with decompensation. Hepatocellular carcinoma is a known complication of cirrhosis, but a rare occurrence in Wilson disease. We present a case of neurological Wilson disease, who later developed decompensated cirrhosis and hepatocellular carcinoma.

Solar flare loops observations and interpretations

CERN Document Server

Huang, Guangli; Ji, Haisheng; Ning, Zongjun

2018-01-01

This book provides results of analysis of typical solar events, statistical analysis, the diagnostics of energetic electrons and magnetic field, as well as the global behavior of solar flaring loops such as their contraction and expansion. It pays particular attention to analyzing solar flare loops with microwave, hard X-ray, optical and EUV emissions, as well as the theories of their radiation, and electron acceleration/transport. The results concerning influence of the pitch-angle anisotropy of non-thermal electrons on their microwave and hard X-ray emissions, new spectral behaviors in X-ray and microwave bands, and results related to the contraction of flaring loops, are widely discussed in the literature of solar physics. The book is useful for graduate students and researchers in solar and space physics.

SEISMOLOGY OF A LARGE SOLAR CORONAL LOOP FROM EUVI/STEREO OBSERVATIONS OF ITS TRANSVERSE OSCILLATION

International Nuclear Information System (INIS)

Verwichte, E.; Van Doorsselaere, T.; Foullon, C.; Nakariakov, V. M.; Aschwanden, M. J.

2009-01-01

The first analysis of a transverse loop oscillation observed by both Solar TErrestrial RElations Observatories (STEREO) spacecraft is presented, for an event on the 2007 June 27 as seen by the Extreme Ultraviolet Imager (EUVI). The three-dimensional loop geometry is determined using a three-dimensional reconstruction with a semicircular loop model, which allows for an accurate measurement of the loop length. The plane of wave polarization is found from comparison with a simulated loop model and shows that the oscillation is a fundamental horizontally polarized fast magnetoacoustic kink mode. The oscillation is characterized using an automated method and the results from both spacecraft are found to match closely. The oscillation period is 630 ± 30 s and the damping time is 1000 ± 300 s. Also, clear intensity variations associated with the transverse loop oscillations are reported for the first time. They are shown to be caused by the effect of line-of-sight integration. The Alfven speed and coronal magnetic field derived using coronal seismology are discussed. This study shows that EUVI/STEREO observations achieve an adequate accuracy for studying long-period, large-amplitude transverse loop oscillations.

OBSERVATIONS OF LINEAR POLARIZATION IN A SOLAR CORONAL LOOP PROMINENCE SYSTEM OBSERVED NEAR 6173 Å

Energy Technology Data Exchange (ETDEWEB)

Saint-Hilaire, Pascal; Martínez Oliveros, Juan-Carlos; Hudson, Hugh S.; Krucker, Säm; Bain, Hazel [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Schou, Jesper [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Couvidat, Sébastien, E-mail: shilaire@ssl.berkeley.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2014-05-10

White-light observations by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager of a loop-prominence system occurring in the aftermath of an X-class flare on 2013 May 13 near the eastern solar limb show a linearly polarized component, reaching up to ∼20% at an altitude of ∼33 Mm, about the maximum amount expected if the emission were due solely to Thomson scattering of photospheric light by the coronal material. The mass associated with the polarized component was 8.2 × 10{sup 14} g. At 15 Mm altitude, the brightest part of the loop was 3(±0.5)% linearly polarized, only about 20% of that expected from pure Thomson scattering, indicating the presence of an additional unpolarized component at wavelengths near Fe I (617.33 nm). We estimate the free electron density of the white-light loop system to possibly be as high as 1.8 × 10{sup 12} cm{sup –3}.

Mixed heavy–light matching in the Universal One-Loop Effective Action

International Nuclear Information System (INIS)

Ellis, Sebastian A.R.; Quevillon, Jérémie; You, Tevong; Zhang, Zhengkang

2016-01-01

Recently, a general result for evaluating the path integral at one loop was obtained in the form of the Universal One-Loop Effective Action. It may be used to derive effective field theory operators of dimensions up to six, by evaluating the traces of matrices in this expression, with the mass dependence encapsulated in the universal coefficients. Here we show that it can account for loops of mixed heavy–light particles in the matching procedure. Our prescription for computing these mixed contributions to the Wilson coefficients is conceptually simple. Moreover it has the advantage of maintaining the universal structure of the effective action, which we illustrate using the example of integrating out a heavy electroweak triplet scalar coupling to a light Higgs doublet. Finally we also identify new structures that were previously neglected in the universal results.

Computerized abdominal tomography in Wilson's disease

Energy Technology Data Exchange (ETDEWEB)

Tsuchikura, Keiko; Ogawa, Teruyuki; Nakajima, Akihisa; Ono, Yasuhiko

1986-05-01

Cranial and abdominal computerized tomography (CT) was performed in a 10-year-old boy with Wilson's disease complicated by liver cirrhosis. Abdominal CT showed diffuse high density areas over the whole part of the liver propably due to copper sediments, although there was no abnormal cranial CT findings. Decreased high density area of the liver was seen 60 days after the administration of D-penicillamine, suggesting the excretion of copper from the liver. Abdominal CT, as well as cranial CT, may be of help to diagnose Wilson's disease and evaluate therapeutic effects. (Namekawa, K.).

Ebot, Wilson Atem

African Journals Online (AJOL)

Ebot, Wilson Atem. Vol 8-9, No 1 (1995) - Articles Language and socio-cultural change in Ejagham Abstract PDF. ISSN: 1016-0728. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

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 .

HFE gene mutations and Wilson's disease in Sardinia.

Science.gov (United States)

Sorbello, Orazio; Sini, Margherita; Civolani, Alberto; Demelia, Luigi

2010-03-01

Hypocaeruloplasminaemia can lead to tissue iron storage in Wilson's disease and the possibility of iron overload in long-term overtreated patients should be considered. The HFE gene encodes a protein that is intimately involved in intestinal iron absorption. The aim of this study was to determine the prevalence of the HFE gene mutation, its role in iron metabolism of Wilson's disease patients and the interplay of therapy in copper and iron homeostasis. The records of 32 patients with Wilson's disease were reviewed for iron and copper indices, HFE gene mutations and liver biopsy. Twenty-six patients were negative for HFE gene mutations and did not present significant alterations of iron metabolism. The HFE mutation was significantly associated with increased hepatic iron content (PHFE gene wild-type. The HFE gene mutations may be an addictional factor in iron overload in Wilson's disease. Our results showed that an adjustment of dosage of drugs could prevent further iron overload induced by overtreatment only in patients HFE wild-type. 2009. Published by Elsevier Ltd.

The Legacy of G. Wilson Knight

Directory of Open Access Journals (Sweden)

Raw Laurence

2017-06-01

Full Text Available G. Wilson Knight (1897-1985 was one of the most influential Shakespearean critics of the mid-twentieth century. This piece surveys his work from 1930 until the early 1980s. Much affected by the First World War, he developed a style of criticism based on Christian principles of respect for other people and belief in an all-powerful God. Many of his most famous pieces (in THE WHEEL OF FIRE, for instance argue for human insignificance in an indifferent universe. It is up to all of us as individuals to develop methods of coping with this world. Wilson Knight’s ideas gained particular currency during the Second World War, when Britain’s very future seemed at risk due to the threat of Nazi invasion. Although much derided for his use of transcendent language—especially by his contemporary F. R. Leavis—Wilson Knight’s ideas seem to have acquired new significance in a globalized world, where individuals fight to main their identity in a technology-driven environment.

Ted Wilson passes on the torch

CERN Multimedia

2003-01-01

As part of the Laboratory's outreach programme, the CERN Accelerator School (CAS) brings together students and experienced physicists from all over the world with the aim of promoting the understanding of accelerator physics. As head of the School for 11 years, Ted Wilson became a CERN ambassador to the outside community. He retired in March, handing over the reigns of the CAS to Daniel Brandt. Ted Wilson and his assistant, Suzanne von Wartburg, during an EPAC meeting in 1994.The accelerator schools allowed some time for relaxation in the local surrounding for students as well as for the director of CAS.As a boy, Ted Wilson could have embarked on a career in pop music rather than physics, rubbing shoulders at secondary school in Liverpool with two of the future Beatles. But prefering classical music and answering the call of science, he took the more serious of the two paths, studying physics first at Oxford University then at the Rutherford Laboratory. After a year at CERN and four years at the Rutherford La...

Solar rotation measurements at Mount Wilson. Pt. 2

International Nuclear Information System (INIS)

Labonte, B.J.; Howard, R.; Carnegie Institution of Washington, Pasadena

1981-01-01

Possible sources of systematic error in solar Doppler rotational velocities are examined. Scattered light is shown to affect the Mount Wilson solar rotation results, but this effect is not enough to bring the spectroscopic results in coincidence with the sunspot rotation. Interference fringes at the spectrograph focus at Mount Wilson have in two intervals affected the rotation results. It has been possible to correlate this error with temperature and thus correct for it. A misalignment between the entrance and exit slits is a possible source of error, but for the Mount Wilson slit configuration the amplitude of this effect is negligibly small. Rapid scanning of the solar image also produces no measurable effect. (orig.)

August Wilson's Presentation of Interracial Movements in 1960s

Science.gov (United States)

Li, Yanghua

2018-01-01

August Wilson's "Two Trains Running" tells the life predicaments of the patrons at Memphis' restaurant in the 1960s. Though Wilson avoids addressing the interracial conflicts and movements on stage to eschew protesting and propaganda, they as social background could not be totally ignored in the play. The paper analyses Wilson's use of…

Is blinking of the eyes affected in extrapyramidal disorders? An interesting observation in a patient with Wilson disease.

Science.gov (United States)

Verma, Rajesh; Lalla, Rakesh; Patil, Tushar B

2012-11-27

Blinking of eye is a routine human activity which seldom attracts any attention of clinicians in health and disease. There is experimental evidence that blink rate is affected in extrapyramidal disorders affecting the balance of these neurotransmitters. However, no observations regarding blink rate in Wilson disease (WD) have been reported previously. We report a patient of WD with an increased spontaneous blink rate. A 24-year-old lady presented complaining of tremulousness of both upper limbs and head for 2 years, dysphagia and difficulty in speaking for 1.5 years and abnormal behaviour for last 1 year. We observed that her blink rate at rest was 32/min. Serum ceruloplasmin level was low (0.08 g/l). The patient was started on therapy with D-penicillamine, zinc sulphate, levodopa-carbidopa and trihexiphenidyl. At 1-month follow-up, patient's tremors were markedly decreased and blink rate at rest was decreased to 12/min.

Well-observed dynamics of flaring and peripheral coronal magnetic loops during an M-class limb flare

International Nuclear Information System (INIS)

Shen, Jinhua; Zhou, Tuanhui; Ji, Haisheng; Feng, Li; Wiegelmann, Thomas; Inhester, Bernd

2014-01-01

In this paper, we present a variety of well-observed dynamic behaviors for the flaring and peripheral magnetic loops of the M6.6 class extreme limb flare that occurred on 2011 February 24 (SOL2011-02-24T07:20) from EUV observations by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory and X-ray observations by RHESSI. The flaring loop motion confirms the earlier contraction-expansion picture. We find that the U-shaped trajectory delineated by the X-ray corona source of the flare roughly follows the direction of a filament eruption associated with the flare. Different temperature structures of the coronal source during the contraction and expansion phases strongly suggest different kinds of magnetic reconnection processes. For some peripheral loops, we discover that their dynamics are closely correlated with the filament eruption. During the slow rising to abrupt, fast rising of the filament, overlying peripheral magnetic loops display different responses. Two magnetic loops on the elbow of the active region had a slow descending motion followed by an abrupt successive fast contraction, while magnetic loops on the top of the filament were pushed outward, slowly being inflated for a while and then erupting as a moving front. We show that the filament activation and eruption play a dominant role in determining the dynamics of the overlying peripheral coronal magnetic loops.

Evidence for two-loop interaction from IRIS and SDO observations of penumbral brightenings

Science.gov (United States)

Alissandrakis, C. E.; Koukras, A.; Patsourakos, S.; Nindos, A.

2017-07-01

Aims: We investigate small scale energy release events which can provide clues on the heating mechanism of the solar corona. Methods: We analyzed spectral and imaging data from the Interface Region Imaging Spectrograph (IRIS), images from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatoty (SDO), and magnetograms from the Helioseismic and Magnetic Imager (HMI) aboard SDO. Results: We report observations of small flaring loops in the penumbra of a large sunspot on July 19, 2013. Our main event consisted of a loop spanning 15'', from the umbral-penumbral boundary to an opposite polarity region outside the penumbra. It lasted approximately 10 min with a two minute impulsive peak and was observed in all AIA/SDO channels, while the IRIS slit was located near its penumbral footpoint. Mass motions with an apparent velocity of 100 km s-1 were detected beyond the brightening, starting in the rise phase of the impulsive peak; these were apparently associated with a higher-lying loop. We interpret these motions in terms of two-loop interaction. IRIS spectra in both the C II and Si iv lines showed very extended wings, up to about 400 km s-1, first in the blue (upflows) and subsequently in the red wing. In addition to the strong lines, emission was detected in the weak lines of Cl I, O I and C I, as well as in the Mg II triplet lines. Absorption features in the profiles of the C II doublet, the Si iv doublet and the Mg II h and k lines indicate the existence of material with a lower source function between the brightening and the observer. We attribute this absorption to the higher loop and this adds further credibility to the two-loop interaction hypothesis. Tilts were detected in the absorption spectra, as well as in the spectra of Cl I, O I, and C I lines, possibly indicating rotational motions from the untwisting of magnetic flux tubes. Conclusions: We conclude that the absorption features in the C II, Si iv and Mg II profiles originate in a higher

Microstructure assessment of the thalamus in Wilson's disease using diffusion tensor imaging

International Nuclear Information System (INIS)

Li, G.; Zhou, X.; Xu, P.; Pan, X.; Chen, Y.

2014-01-01

Aim: To assess diffusion changes of the thalamus in Wilson's disease using diffusion tensor imaging (DTI). Materials and methods: Fifteen patients with Wilson's disease and an abnormal signal in the thalamus (designated as group 1) and 18 patients with Wilson's disease with a normal-appearing thalamus (designated as group 2) at conventional magnetic resonance imaging (MRI) were recruited. Fifteen age-matched and sex-matched healthy volunteers were also enrolled as the control group (designated as group 3). The fractional anisotropy (FA), primary eigenvalue (λ1), second eigenvalue (λ2), and third eigenvalue (λ3) of the thalamus were measured and the differences were compared. Results: The FA values of the thalamus were different in the three groups (group 1: 0.36 ± 0.02; group 2: 0.38 ± 0.02; group 3: 0.43 ± 0.02; F = 54.51, p 2 /s, 1.11 ± 0.06 mm 2 /s, and 1.10 ± 0.04 mm 2 /s of λ1 in group 1, group 2, and group 3, respectively; 0.82 ± 0.08 mm 2 /s, 0.78 ± 0.05 mm 2 /s, and 0.72 ± 0.02 mm 2 /s of λ2 in group 1, group 2, and group 3, respectively; 0.52 ± 0.05 mm 2 /s, 0.49 ± 0.06 mm 2 /s, and 0.42 ± 0.06 mm 2 /s of λ3 in group 1, group 2, and group 3, respectively; F = 1.65, p = 0.203 of λ1; F = 10.55, p < 0.001 of λ2; F = 4.21, p = 0.021 of λ3; respectively). A statistically significant difference in the λ2 value was observed between group 1 and group 3 (p < 0.001) and group 2 and group 3 (p = 0.005). A statistically significant difference in the λ3 value was also observed between group 1 and group 3 (p = 0.007). No significant difference in the λ1 value was noted between each of the two groups. Conclusions: Damage of the thalamus in Wilson's disease patients can be detected using DTI. DTI may provide information regarding thalamus damage in patients with Wilson's disease before abnormal signals on conventional MRI

Operator product expansion on the lattice: analytic Wilson coefficients

Science.gov (United States)

Perlt, Holger

2006-12-01

We present first results for Wilson coefficients of operators up to first order in the covariant deriva- tives for the case of Wilson fermions. They are derived from the off-shell Compton scattering amplitude Wµν (a, p, q) of massless quarks with momentum p. The Wilson coefficients are clas- sified according to the transformation of the corresponding operators under the hypercubic group H(4). We give selected examples for a special choice of the momentum transfer q. All Wil- son coefficients are given in closed analytic form and in an expansion in powers of a up to first corrections.

Density-dependent mass gain by Wilson's Warblers during stopover

Science.gov (United States)

Jeffrey F. Kelly; Linda S. DeLay; Deborah M. Finch

2002-01-01

The need restore energetic reserves at stopover sites constrains avian migration ecology. To describe that constraint, we examined relationships among mass gained by Wilson's Warblers (Wilsonia pusilla) during stopover, abundance of Wilson's Warblers (i.e. capture rate), and arthropod abundance during autumn migration. We found that amount...

How Is Wilson Disease Inherited?

Science.gov (United States)

... News & Announcements Wilson's Warriors Events Back The Big WOW 2018 Annual Conference WDA Publications Back Downloads Corporate Sponsorship Forms Membership Forms Resources The Big WOW Newsletters News Copper Connection Newsletter Resources Centers of ...

How Is Wilson Disease Diagnosed?

Science.gov (United States)

... News & Announcements Wilson's Warriors Events Back The Big WOW 2018 Annual Conference WDA Publications Back Downloads Corporate Sponsorship Forms Membership Forms Resources The Big WOW Newsletters News Copper Connection Newsletter Resources Centers of ...

SIMULTANEOUS OBSERVATION OF SOLAR OSCILLATIONS ASSOCIATED WITH CORONAL LOOPS FROM THE PHOTOSPHERE TO THE CORONA

Energy Technology Data Exchange (ETDEWEB)

Su, J. T.; Liu, S.; Zhang, Y. Z.; Zhao, H.; Xu, H. Q.; Xie, W. B. [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China); Liu, Y. [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2013-01-01

The solar oscillations along one coronal loop in AR 11504 are observed simultaneously in white light emission and Doppler velocity by SDO/HMI, and in UV and EUV emissions by SDO/AIA. The technique of the time-distance diagram is used to detect the propagating oscillations of the emission intensities along the loop. We find that although all the oscillation signals were intercorrelated, the low chromospheric oscillation correlated more closely to the oscillations of the transition region and corona than to those of the photosphere. Situated above the sunspot, the oscillation periods were {approx}3 minutes in the UV/EUV emissions; however, moving away from the sunspot and into the quiet Sun, the periods became longer, e.g., up to {approx}5 minutes or more. In addition, along another loop we observe both the high-speed outflows and oscillations, which roughly had a one-to-one corresponding relationship. This indicates that the solar periodic oscillations may modulate the magnetic reconnections between the loops of the high and low altitudes that drive the high-speed outflows along the loop.

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}.

High-Altitude Closed Magnetic Loops at Mars Observed by MAVEN

Science.gov (United States)

Xu, Shaosui; Mitchell, David; Luhmann, Janet; Ma, Yingjuan; Fang, Xiaohua; Harada, Yuki; Hara, Takuya; Brain, David; Weber, Tristan; Mazelle, Christian; DiBraccio, Gina A.

2017-11-01

With electron and magnetic field data obtained by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we have identified closed magnetic field lines, with both foot points embedded in the dayside ionosphere, extending up to 6,200 km altitude into the Martian tail. This topology is deduced from photoelectrons produced in the dayside ionosphere being observed traveling both parallel and antiparallel to the magnetic field. At trapped-zone pitch angles (within a range centered on 90° where electrons magnetically reflect before interacting with the atmosphere), cases with either solar wind electrons or photoelectrons have been found, indicating different formation mechanisms for these closed loops. These large closed loops are present in MHD simulations. The case with field-aligned photoelectrons mixed with solar wind electrons having trapped-zone pitch angles is likely to be associated with reconnection, while the case with photoelectrons at all pitch angles is probably due to closed field lines being pulled tailward by the surrounding plasma flow. By utilizing an algorithm for distinguishing photoelectrons from solar wind electrons in pitch angle-resolved energy spectra, we systematically map the spatial distribution and occurrence rate of these closed magnetic loops over the region sampled by the MAVEN orbit. We find that the occurrence rate ranges from a few percent to a few tens of percent outside of the optical shadow and less than one percent within the shadow. These observations can be used to investigate the general magnetic topology in the tail, which is relevant to cold ion escape, reconnection, and flux ropes.

Syndrome parkinsonien secondaire à une maladie de Wilson chez ...

African Journals Online (AJOL)

Nous apportons une observation d'un cas de la maladie de Wilson, révélé par un syndrome parkinsonien. Le diagnostic a reposé sur les troubles neuropsychiques, la présence de l'anneau cornéen de Kayser-Fleischer, et les troubles du métabolisme du cuivre. Le scanner cérébral était normal, et l'IRM cérébrale a montré ...

CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

International Nuclear Information System (INIS)

Lionello, Roberto; Linker, Jon A.; Mikić, Zoran; Alexander, Caroline E.; Winebarger, Amy R.

2016-01-01

The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delay is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored

Woodrow Wilson: Prophet of Peace. Teaching with Historic Places.

Science.gov (United States)

Goehner, Thomas B.

This lesson describes President Woodrow Wilson's struggle with and his ultimate failure at achieving lasting world peace through the League of Nations. The lesson focuses on November 23, 1923, the eve of the fifth anniversary of the Armistice that concluded World War I, when a frail and ill Wilson was ready to deliver a commemorative address by…

Anesthesia in Mowat-Wilson syndrome: information on 11 Italian patients

Directory of Open Access Journals (Sweden)

Marianna Spunton

2018-03-01

Full Text Available Mowat-Wilson syndrome is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene and characterized by typical clinical features. The congenital malformations typical of this syndrome call for early diagnostic and surgical procedures requiring general anesthesia, but few information about the anesthesiology management of such patients is available. We enrolled 11 families of patients with Mowat-Wilson syndrome who had undergone surgical or diagnostic procedures requiring general anesthesia, and sent them a retrospective questionnaire including 16 open questions about the procedures. They were further contacted by phone for a semi-structured interview. A total of 37 procedures requiring general anesthesia was reported in 11 patients. Only two patients reported anesthesia-related complications during the procedure. No true additional anesthesia-related risk was present for the patients with MW syndrome, besides difficult intubation, weaning and lower respiratory tract infection. Perception of risk, however, is derived by non-medical observation on the part of the parents.

Parallel tempering in full QCD with Wilson fermions

International Nuclear Information System (INIS)

Ilgenfritz, E.-M.; Kerler, W.; Mueller-Preussker, M.; Stueben, H.

2002-01-01

We study the performance of QCD simulations with dynamical Wilson fermions by combining the hybrid Monte Carlo algorithm with parallel tempering on 10 4 and 12 4 lattices. In order to compare tempered with standard simulations, covariance matrices between subensembles have to be formulated and evaluated using the general properties of autocorrelations of the parallel tempering algorithm. We find that rendering the hopping parameter κ dynamical does not lead to an essential improvement. We point out possible reasons for this observation and discuss more suitable ways of applying parallel tempering to QCD

War, Medicine, and Cultural Diplomacy in the Americas: Frank Wilson and Brazilian cardiology.

Science.gov (United States)

Kropf, Simone P; Howell, Joel D

2017-10-01

American cultural diplomacy played a key role in the institutionalization of Brazilian cardiology. In 1942, Frank Wilson, an internationally recognized pioneer in electrocardiography, made an extended wartime visit to Rio de Janeiro and São Paulo. The visit was sponsored by the United States Department of State as part of Roosevelt's Good Neighbor Policy and brought Wilson together with a group of physicians who would establish the specialty of cardiology in Brazil. This US cultural and diplomatic initiative strengthened an academic network that was already evolving and would eventually prove to be of benefit to both sides. Latin American physicians began in the 1920s to visit Wilson's laboratory at the University of Michigan, where they established the relationships on which Wilson would build. While affiliation with the "Wilson school" advanced the cause of Brazilian cardiologists who sought to establish themselves as specialists, cooperation with Latin American physicians benefitted Wilson in his pursuit of wider recognition for his innovations in the use of electrocardiography (ECG). Wilson's identity as a scientific ambassador to Latin America helped in legitimating his approach to the clinical application of the ECG. A close examination of Wilson's relationship to Brazilian cardiology demonstrates the role played by science and medicine as a part of wartime cultural diplomacy, as well as the dynamics of the transnational circulation of scientific knowledge and practices. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analytic result for the two-loop six-point NMHV amplitude in N=4 super Yang-Mills theory

CERN Document Server

Dixon, Lance J.; Henn, Johannes M.

2012-01-01

We provide a simple analytic formula for the two-loop six-point ratio function of planar N = 4 super Yang-Mills theory. This result extends the analytic knowledge of multi-loop six-point amplitudes beyond those with maximal helicity violation. We make a natural ansatz for the symbols of the relevant functions appearing in the two-loop amplitude, and impose various consistency conditions, including symmetry, the absence of spurious poles, the correct collinear behaviour, and agreement with the operator product expansion for light-like (super) Wilson loops. This information reduces the ansatz to a small number of relatively simple functions. In order to fix these parameters uniquely, we utilize an explicit representation of the amplitude in terms of loop integrals that can be evaluated analytically in various kinematic limits. The final compact analytic result is expressed in terms of classical polylogarithms, whose arguments are rational functions of the dual conformal cross-ratios, plus precisely two function...

Subtracting infrared renormalons from Wilson coefficients: Uniqueness and power dependences on ΛQCD

Science.gov (United States)

Mishima, Go; Sumino, Yukinari; Takaura, Hiromasa

2017-06-01

In the context of operator product expansion (OPE) and using the large-β0 approximation, we propose a method to define Wilson coefficients free from uncertainties due to IR renormalons. We first introduce a general observable X (Q2) with an explicit IR cutoff, and then we extract a genuine UV contribution XUV as a cutoff-independent part. XUV includes power corrections ˜(ΛQCD2/Q2)n which are independent of renormalons. Using the integration-by-regions method, we observe that XUV coincides with the leading Wilson coefficient in OPE and also clarify that the power corrections originate from UV region. We examine scheme dependence of XUV and single out a specific scheme favorable in terms of analytical properties. Our method would be optimal with respect to systematicity, analyticity and stability. We test our formulation with the examples of the Adler function, QCD force between Q Q ¯, and R -ratio in e+e- collision.

Observation and Modeling of Chromospheric Evaporation in a Coronal Loop Related to Active Region Transient Brightening

Science.gov (United States)

Gupta, G. R.; Sarkar, Aveek; Tripathi, Durgesh

2018-04-01

Using the observations recorded by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory and the Interface Region Imaging Spectrograph (IRIS) and the Extreme-ultraviolet Imaging Spectrometer and X-Ray Telescope both on board Hinode, we present evidence of chromospheric evaporation in a coronal loop after the occurrence of two active region transient brightenings (ARTBs) at the two footpoints. The chromospheric evaporation started nearly simultaneously in all of the three hot channels of AIA 131, 94, and 335 Å and was observed to be temperature dependent, being fastest in the highest temperature channel. The whole loop became fully brightened following the ARTBs after ≈25 s in 131 Å, ≈40 s in 94 Å, and ≈6.5 minutes in 335 Å. The differential emission measurements at the two footpoints (i.e., of two ARTBs) and at the loop top suggest that the plasma attained a maximum temperature of ∼10 MK at all these locations. The spectroscopic observations from IRIS revealed the presence of redshifted emission of ∼20 km s‑1 in cooler lines like C II and Si IV during the ARTBs that was cotemporal with the evaporation flow at the footpoint of the loop. During the ARTBs, the line width of C II and Si IV increased nearly by a factor of two during the peak emission. Moreover, enhancement in the line width preceded that in the Doppler shift, which again preceded enhancement in the intensity. The observed results were qualitatively reproduced by 1D hydrodynamic simulations, where energy was deposited at both of the footpoints of a monolithic coronal loop that mimicked the ARTBs identified in the observations.

Mowat–Wilson syndrome – case study

Directory of Open Access Journals (Sweden)

Kamil Faltin

2016-06-01

Full Text Available Mowat–Wilson syndrome is a rare genetic condition characterised by a number of congenital anomalies, including facial dysmorphia, heart and kidney anomalies, Hirschsprung’s disease, intellectual disability and abnormalities of reproductive organs. In the paper, we present a case of a girl who was admitted to the Department of Paediatrics, Immunology and Nephrology at the age of 3 months, with a suspicion of tubulointerstitial nephritis. The patient had facial dysmorphia, congenital malformations of the nervous system and Hirschsprung’s disease. During hospitalisation, congenital urinary anomalies (bilateral vesicoureteral reflux and heart defects were diagnosed. On the basis of the clinical picture, the diagnostics was expanded to genetic tests for Mowat–Wilson syndrome, which revealed an 857_858delAG pathogenic mutation in one of the ZEB2 gene alleles (exon 7 – one of the rarer causes of Mowat–Wilson syndrome. At present, the girl is 13 months old. Her development is delayed. Currently, the girl is under multidisciplinary care and she is undergoing intensive rehabilitation. The knowledge of the syndrome’s clinical features allows a faster diagnosis to be made and multispecialty care to be provided to the child.

Sextet Model with Wilson Fermions

DEFF Research Database (Denmark)

Hansen, Martin; Pica, Claudio

2017-01-01

We present new results from our ongoing study of the SU(3) sextet model with two flavors in the two-index symmetric representation of the gauge group. In the simulations use unimproved Wilson fermions to investigate the infrared properties of the model. We have previously presented results...

The Wilson films--Huntington's chorea.

Science.gov (United States)

Klein, Christine

2011-12-01

Wilson's Queen Square Case 9 with Huntington's chorea shows a 68-year-old man with mild to moderate generalized chorea, impaired fixation, and probable cognitive decline in keeping with a diagnosis of Huntington's disease (HD). An age of onset in the late sixties and a negative family history suggest a relatively small expanded trinucleotide repeat in the HTT gene in the patient and reduced penetrance of an even shorter repeat allele in one of his parents. A highly sensitive and specific gene test has been offered worldwide for diagnostic testing of HD for almost two decades. This test, obviously unavailable at Wilson's times, became the historic frontrunner for guidelines of symptomatic, presymptomatic, and prenatal testing for an adult-onset neurodegenerative disorder. Regarding treatment of HD, however, we are still awaiting the successful translation of research results into the development of effective cause-directed, neuropreventive and neurorestaurative therapies. Copyright © 2011 Movement Disorder Society.

Determination of low-energy constants of Wilson chiral perturbation theory

International Nuclear Information System (INIS)

Herdoiza, Gregorio; Univ. Autonoma de Madrid, Contoblanco; Univ. Autonoma de Madrid; Jansen, Karl; Univ. Cyprus, Nicosia; Michael, Chris; Ottnad, Konstantin; Urbach, Carsten; Univ. Bonn

2013-03-01

By matching Wilson twisted mass lattice QCD determinations of pseudoscalar meson masses to Wilson Chiral Perturbation Theory we determine the low-energy constants W 6 ' , W 8 ' and their linear combination c 2 . We explore the dependence of these low-energy constants on the choice of the lattice action and on the number of dynamical flavours.

The cerebral lesions of Wilson's disease on computer tomography

International Nuclear Information System (INIS)

Rodiek, S.

1983-01-01

M. Wilson is often being mistaken as such for several years and kept for psychosis or another extrapyramidal disease. When the disease causes neuro-psychiatric symptoms a certain part of cases shows typical lesions in CT mainly affecting the Nucleus lentiformis and frontal cortex. From our own material two cases of M. Wilson are shown and compared with two other cases with identical patterns of lesions following toxic and hypoxic brain damage. (orig.) [de

Robert Wilson's Invitation to Insanity.

Science.gov (United States)

Stephens, Judith L.

The plays of stage director Robert Wilson are devices presenting alternative modes of perception to theatre audiences accustomed to verbal/aural structures of experience. Uniting his interests in the arts and therapy, his plays create a theatrical event promoting empathy with the perceptions of the mentally or physically handicapped and…

Neuroimaging findings in Mowat-Wilson syndrome

DEFF Research Database (Denmark)

Garavelli, Livia; Ivanovski, Ivan; Caraffi, Stefano Giuseppe

2017-01-01

PURPOSE: Mowat-Wilson syndrome (MWS) is a genetic disease characterized by distinctive facial features, moderate to severe intellectual disability, and congenital malformations, including Hirschsprung disease, genital and eye anomalies, and congenital heart defects, caused by haploinsufficiency o...

The 3-loop pure singlet heavy flavor contributions to the structure function F2(x,Q2 and the anomalous dimension

Directory of Open Access Journals (Sweden)

J. Ablinger

2015-01-01

Full Text Available The pure singlet asymptotic heavy flavor corrections to 3-loop order for the deep-inelastic scattering structure function F2(x,Q2 and the corresponding transition matrix element AQq(3,PS in the variable flavor number scheme are computed. In Mellin-N space these inclusive quantities depend on generalized harmonic sums. We also recalculate the complete 3-loop pure singlet anomalous dimension for the first time. Numerical results for the Wilson coefficients, the operator matrix element and the contribution to the structure function F2(x,Q2 are presented.

The 3-loop pure singlet heavy flavor contributions to the structure function F2(x,Q2) and the anomalous dimension

International Nuclear Information System (INIS)

Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; Manteuffel, A. von; Schneider, C.

2015-01-01

The pure singlet asymptotic heavy flavor corrections to 3-loop order for the deep-inelastic scattering structure function F 2 (x,Q 2 ) and the corresponding transition matrix element A Qq (3),PS in the variable flavor number scheme are computed. In Mellin-N space these inclusive quantities depend on generalized harmonic sums. We also recalculate the complete 3-loop pure singlet anomalous dimension for the first time. Numerical results for the Wilson coefficients, the operator matrix element and the contribution to the structure function F 2 (x,Q 2 ) are presented

Kenneth G Wilson (1936–2013)

Indian Academy of Sciences (India)

The best reference for anyone interested in the development of Wilson's thinking in this period ... work on the critical point was a seminar in the Chemistry Department by his ... The basic theoretical tool used was the renormalization group.

Determination of low-energy constants of Wilson chiral perturbation theory

Energy Technology Data Exchange (ETDEWEB)

Herdoiza, Gregorio [Mainz Univ. (Germany). Inst fuer Kernphysik, PRISMA Cluster of Excellence; Univ. Autonoma de Madrid, Contoblanco (Spain). Dept. de Fisica Teorica; Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica UAM/CSIC; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Univ. Cyprus, Nicosia (Cyprus). Dept. of Physics; Michael, Chris [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Ottnad, Konstantin; Urbach, Carsten [Bonn Univ. (Germany). Helmholtz-Institut fuer Strahlen und Kernphysik; Univ. Bonn (Germany). Bethe Center for Theoretical Physics; Collaboration: European Twisted Mass Collaboration

2013-03-15

By matching Wilson twisted mass lattice QCD determinations of pseudoscalar meson masses to Wilson Chiral Perturbation Theory we determine the low-energy constants W{sub 6}{sup '}, W{sub 8}{sup '} and their linear combination c{sub 2}. We explore the dependence of these low-energy constants on the choice of the lattice action and on the number of dynamical flavours.

Towards a nonperturbative calculation of weak Hamiltonian Wilson coefficients

Science.gov (United States)

Bruno, Mattia; Lehner, Christoph; Soni, Amarjit; Rbc; Ukqcd Collaborations

2018-04-01

We propose a method to compute the Wilson coefficients of the weak effective Hamiltonian to all orders in the strong coupling constant using Lattice QCD simulations. We perform our calculations adopting an unphysically light weak boson mass of around 2 GeV. We demonstrate that systematic errors for the Wilson coefficients C1 and C2 , related to the current-current four-quark operators, can be controlled and present a path towards precise determinations in subsequent works.

Gluon scattering in N=4 super Yang-Mills at finite temperature

International Nuclear Information System (INIS)

Ito, Katsushi; Iwasaki, Koh; Nastase, Horatiu

2008-01-01

We extend the AdS/CFT prescription of Alday and Maldacena to finite temperature T, defining an amplitude for gluon scattering in N=4 Super Yang-Mills at strong coupling from string theory. It is defined by a lightlike 'Wilson loop' living at the horizon of the T-dual to the black hole in AdS space. Unlike the zero temperature case, this is different from the Wilson loop contour defined at the boundary of the AdS black hole metric. Thus at nonzero T there is no relation between gluon scattering amplitudes and the Wilson loop. We calculate a gauge theory observable that can be interpreted as the amplitude at strong coupling for forward scattering of a low energy gluon (E >T) in both cutoff and generalized dimensional regularization. The generalized dimensional regularization is defined in string theory as an IR modified dimensional reduction. For this calculation, the corresponding usual Wilson loop of the same boundary shape was argued to be related to the jet quenching parameter of the finite temperature N=4 SYM plasma, while the gluon scattering amplitude is related to the viscosity coefficient. (author)

B-physics with N{sub f}=2 Wilson fermions

Energy Technology Data Exchange (ETDEWEB)

Bernardoni, F.; Simma, H.; Sommer, R. [John von Neumann-Institut fuer Computing NIC/DESY, Zeuthen (Germany)] [and others

2013-09-15

We report the final results of the ALPHA collaboration for some B-physics observables: f{sub B}, f{sub B{sub s}} and m{sub b}. We employ CLS configurations with 2 flavors of O(a) improved Wilson fermions in the sea and pion masses ranging down to 190 MeV. The b-quark is treated in HQET to order 1/m{sub b}. The renormalization, the matching and the improvement were performed non-perturbatively, and three lattice spacings reaching a=0.048 fm are used in the continuum extrapolation.

PHOTOSPHERIC PROPERTIES OF WARM EUV LOOPS AND HOT X-RAY LOOPS

Energy Technology Data Exchange (ETDEWEB)

Kano, R. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Ueda, K. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Tsuneta, S., E-mail: ryouhei.kano@nao.ac.jp [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan)

2014-02-20

We investigate the photospheric properties (vector magnetic fields and horizontal velocity) of a well-developed active region, NOAA AR 10978, using the Hinode Solar Optical Telescope specifically to determine what gives rise to the temperature difference between ''warm loops'' (1-2 MK), which are coronal loops observed in EUV wavelengths, and ''hot loops'' (>3 MK), coronal loops observed in X-rays. We found that outside sunspots, the magnetic filling factor in the solar network varies with location and is anti-correlated with the horizontal random velocity. If we accept that the observed magnetic features consist of unresolved magnetic flux tubes, this anti-correlation can be explained by the ensemble average of flux-tube motion driven by small-scale random flows. The observed data are consistent with a flux tube width of ∼77 km and horizontal flow at ∼2.6 km s{sup –1} with a spatial scale of ∼120 km. We also found that outside sunspots, there is no significant difference between warm and hot loops either in the magnetic properties (except for the inclination) or in the horizontal random velocity at their footpoints, which are identified with the Hinode X-Ray Telescope and the Transition Region and Coronal Explorer. The energy flux injected into the coronal loops by the observed photospheric motion of the magnetic fields is estimated to be 2 × 10{sup 6} erg s{sup –1} cm{sup –2}, which is the same for both warm and hot loops. This suggests that coronal properties (e.g., loop length) play a more important role in giving rise to temperature differences of active-region coronal loops than photospheric parameters.

Wilson Disease: Case Report

Directory of Open Access Journals (Sweden)

Esra Tuğ

2007-01-01

Full Text Available Wilson Disease (WD is an autosomal recessive hereditary disease of human copper metabolism, which causes hepatic and neuropsychiatric diseases. Estimated prevalence is 1: 30.000. In WD, ATP7B gene located on chromosome 13 (13q14.3-q21.1, coding the protein for hepatic copper transport and, having an important role in copper metabolism has been affected. Clinical findings in WD are complex and, neurological symptoms such as tremor, disartria and psychiatric disorders, acute liver deficiency, chronic hepatit or cirrhosis may develop. For the last year, 27 years old female patient observed in other medical centre owing to benign positional vertigo applied to our department. Her sister and brother have been diagnosed as WD. No peripheral syptoms of hepatic disease or hepatosplenomegaly existed in our patient. Neurological examination was normal to except for positional tremor. Because our patient had rare clinical features for WD and bad prognosis, presented by us to emphasize necessity of the researched of the most frequent mutations seen in Turkiye.

Loop quantum cosmology: from pre-inflationary dynamics to observations

International Nuclear Information System (INIS)

Ashtekar, Abhay; Barrau, Aurélien

2015-01-01

The Planck collaboration has provided us rich information about the early Universe, and a host of new observational missions will soon shed further light on the ‘anomalies’ that appear to exist on the largest angular scales. From a quantum gravity perspective, it is natural to inquire if one can trace back the origin of such puzzling features to Planck scale physics. Loop quantum cosmology provides a promising avenue to explore this issue because of its natural resolution of the big bang singularity. Thanks to advances over the last decade, the theory has matured sufficiently to allow concrete calculations of the phenomenological consequences of its pre-inflationary dynamics. In this article we summarize the current status of the ensuing two-way dialog between quantum gravity and observations. (paper)

REFLECTION OF PROPAGATING SLOW MAGNETO-ACOUSTIC WAVES IN HOT CORONAL LOOPS: MULTI-INSTRUMENT OBSERVATIONS AND NUMERICAL MODELING

Energy Technology Data Exchange (ETDEWEB)

Mandal, Sudip; Banerjee, Dipankar; Pant, Vaibhav [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Yuan, Ding; Fang, Xia; Doorsselaere, Tom Van, E-mail: sudip@iiap.res.in, E-mail: xia.fang@wis.kuleuven.be [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, bus 2400, 3001, Leuven (Belgium)

2016-09-10

Slow MHD waves are important tools for understanding coronal structures and dynamics. In this paper, we report a number of observations from the X-Ray Telescope (XRT) on board HINODE and Solar Dynamic Observatory /Atmospheric Imaging Assembly (AIA) of reflecting longitudinal waves in hot coronal loops. To our knowledge, this is the first report of this kind as seen from the XRT and simultaneously with the AIA. The wave appears after a micro-flare occurs at one of the footpoints. We estimate the density and temperature of the loop plasma by performing differential emission measure (DEM) analysis on the AIA image sequence. The estimated speed of propagation is comparable to or lower than the local sound speed, suggesting it to be a propagating slow wave. The intensity perturbation amplitude, in every case, falls very rapidly as the perturbation moves along the loop and eventually vanishes after one or more reflections. To check the consistency of such reflection signatures with the obtained loop parameters, we perform a 2.5D MHD simulation, which uses the parameters obtained from our observation as inputs, and perform forward modeling to synthesize AIA 94 Å images. Analyzing the synthesized images, we obtain the same properties of the observables as for the real observation. From the analysis we conclude that a footpoint heating can generate a slow wave which then reflects back and forth in the coronal loop before fading. Our analysis of the simulated data shows that the main agent for this damping is anisotropic thermal conduction.

Urban research in a hostile setting: Godfrey Wilson in Broken Hill, Northern Rhodesia, 1938-1940

Directory of Open Access Journals (Sweden)

Karen Tranberg Hansen

Full Text Available Acknowledged for his pioneering urban anthropological research in Broken Hill through the publication of An Essay on the Economics of Detribalization in Northern Rhodesia (Parts I and II, 1940 and 1941, Godfrey Wilson's professional career was cut short by his death during World War II. The late 1990s transfer and cataloguing at the University of Cape Town of the Monica and Godfrey Wilson papers has made an enormously rich research archive accessible to the public. For the first time, Godfrey Wilson's notes from his fieldwork in Broken Hill enable us to examine his research project through his own observations. Based on a preliminary overview of these records and a tentative analysis of some of their contents, this article revisits the Broken Hill research project against the background of the published essay on the economics of detribalisation. Wilson's argument about temporary urbanisation is demonstrated through migration histories, information about length of stay in towns, and an analysis of the economics of urban livelihoods that focuses on wages including rations, household expenditures, and urban-rural transfers. But the published essay barely explains how in fact he conducted his field research. Although there are very few direct indications, we can infer some of his fieldwork practices and field methodology from notes that occasionally evoke an immediate sense of the trials and tribulations of everyday African life in Broken Hill in the early World War II years. How might experiences in the field have influenced Wilson's analysis? Overall, I discuss his work from two angles, first in the context of a time and place characterised by conflicting agendas, and secondly, in retrospect as the conceptual space and time of early World War II colonial Northern Rhodesia have yielded to different explanatory perspectives.

Wilson Martins: between the intelligentsia and the university (1951

Directory of Open Access Journals (Sweden)

Névio de Campos

2012-05-01

Full Text Available Abstract The purpose of this article is to analyze the presence of Ortega y Gasset in the Parana’s State group during the 1950s, especially his influence in the thinking of Wilson Martins, and to emphasize the debate on the ideas of the intellectual and the university. The article discusses about the contributions of this Parana’s thinker on the Parana’s university teaching constituting and organizing process, and emphasizes that the Wilson Martins’ role consisted in promoting the debate on the presence of the intellectual person in modern society, attributing the mission as guardian of the moral and herald of cultural renovation, without forgetting the Brazilian and European political-cultural context as the founding background to higher education. It bases itself on the speech entitled “The rebellion against intelligence and the mission of the university”, that occurred at the University of Parana in 1951, and on the work The History of Brazilian Intelligence, written by Wilson Martins.

New Constraints on Dark Matter Effective Theories from Standard Model Loops

CERN Document Server

Crivellin, Andreas; Procura, Massimiliano

2014-01-01

We consider an effective field theory for a gauge singlet Dirac dark matter (DM) particle interacting with the Standard Model (SM) fields via effective operators suppressed by the scale $\\Lambda \\gtrsim 1$ TeV. We perform a systematic analysis of the leading loop contributions to spin-independent (SI) DM--nucleon scattering using renormalization group evolution between $\\Lambda$ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity-suppressed and spin-dependent can actually contribute to SI scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are comparable to LHC bounds, and will significantly improve in the near future. Interestingly, the loop contribution we find is maximally isospin violating even if the underlying theory is isospin conserving.

Anesthesia in Mowat-Wilson syndrome: information on 11 Italian patients

OpenAIRE

Marianna Spunton; Livia Garavelli; Paola Cerutti Mainardi; Uta Emmig; Enrico Finale; Andrea Guala

2018-01-01

Mowat-Wilson syndrome is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene and characterized by typical clinical features. The congenital malformations typical of this syndrome call for early diagnostic and surgical procedures requiring general anesthesia, but few information about the anesthesiology management of such patients is available. We enrolled 11 families of patients with Mowat-Wilson syndrome who had undergone surgical or diagnostic procedures requiri...

Face of the giant panda sign in Wilson disease

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Sumit Chakraborty

2013-08-01

Full Text Available Wilson disease usually presents with neurologic or hepatic manifestations. Magnetic resonance imaging (MRI of the brain is very informative in diagnosiing of this disease, especially in patients with neurological features. High T2 signal intensity in the corpus striatum is the most commonly encountered MRI finding. The 'face of the giant panda' sign is seen on axial T2-weighted MRI, and results from abnormal signal intensities in the midbrain. Though uncommon, the sign is considered as the pathognomonic MRI sign of Wilson disease.

Homological Order in Three and Four dimensions: Wilson Algebra, Entanglement Entropy and Twist Defects

Science.gov (United States)

Roy, Abhishek; Chen, Xiao; Teo, Jeffrey

2013-03-01

We investigate homological orders in two, three and four dimensions by studying Zk toric code models on simplicial, cellular or in general differential complexes. The ground state degeneracy is obtained from Wilson loop and surface operators, and the homological intersection form. We compute these for a series of closed 3 and 4 dimensional manifolds and study the projective representations of mapping class groups (modular transformations). Braiding statistics between point and string excitations in (3+1)-dimensions or between dual string excitations in (4+1)-dimensions are topologically determined by the higher dimensional linking number, and can be understood by an effective topological field theory. An algorithm for calculating entanglemnent entropy of any bipartition of closed manifolds is presented, and its topological signature is completely characterized homologically. Extrinsic twist defects (or disclinations) are studied in 2,3 and 4 dimensions and are shown to carry exotic fusion and braiding properties. Simons Fellowship

Topology, the Wilson flow and the HMC algorithm

CERN Document Server

Luscher, Martin

2010-01-01

An old and apparently persistent problem in numerical lattice QCD is that the simulations tend to get trapped in a sector of fixed topological charge when the lattice spacing is taken to zero. The effect sets in very rapidly and may invalidate the simulation results in certain cases. In this talk, the issue is discussed using the Wilson flow as a tool. The flow has a simple scaling behaviour and allows one to understand how exactly the topological sectors emerge in the continuum limit. Further studies however suggest that the observed slowdown of the simulations at small lattice spacings is only partly caused by the emergence of the sectors.

MR of the liver in Wilson's disease

International Nuclear Information System (INIS)

Vogl, T.J.; Steiner, S.; Hammerstingl, R.; Schwarz, S.; Kraft, E.; Weinzierl, M.; Felix, R.

1994-01-01

To show that Wilson's disease is one likely cause of multiple low-intensity nodules of the liver we obtained MR images in 16 patients with clinically and histopathologically confirmed Wilson's disease. Corresponding to morphological changes MRI enabled the subdivision of the patients into two groups. Using a T 2 -weighted spin-echo sequence (TR/TE=2000/45-90) liver parenchyma showed multiple tiny low-intensity-nodules surrounded by high-intensity septa in 10 out of 16 patients. 5 patients had also low-intensity nodules in T 1 -weighted images (TR/TE=600/20). In patients of this group histopathology revealed liver cirrhosis (n=7) and fibrosis (n=2). Common feature of this patient group was marked inflammatory cell infiltration into fibrous septa, increase of copper concentration in liver parenchyma and distinct pathological changes of laboratory data. In the remaining 6 patients no pathological change of liver morphology was demonstrated by MRI corresponding to slight histopathological changes of parenchyma and normal laboratory data. As low-intensity nodules surrounded by high intensity septa can be demonstrated in patients with marked inflammatory infiltration of liver parenchyma MRI may help to define Wilson patients with poorer prognosis. In patients with low-intensity nodules of the liver and unknown cause of liver cirrhosis laboratory data and histopathology should be checked when searching for disorders of copper metabolism. (orig.) [de

Modeling active region transient brightenings observed with X-ray telescope as multi-stranded loops

Energy Technology Data Exchange (ETDEWEB)

Kobelski, Adam R.; McKenzie, David E. [Department of Physics, P.O. Box 173840, Montana State University, Bozeman, MT 59717-3840 (United States); Donachie, Martin, E-mail: kobelski@solar.physics.montana.edu [University of Glasgow, Glasgow, G128QQ, Scotland (United Kingdom)

2014-05-10

Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

Modeling active region transient brightenings observed with X-ray telescope as multi-stranded loops

International Nuclear Information System (INIS)

Kobelski, Adam R.; McKenzie, David E.; Donachie, Martin

2014-01-01

Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

Wilson fermions at finite temperature

International Nuclear Information System (INIS)

Creutz, M.

1996-01-01

The author conjectures on the phase structure expected for lattice gauge theory with two flavors of Wilson fermions, concentrating on large values of the hopping parameter. Numerous phases are expected, including the conventional confinement and deconfinement phases, as well as an Aoki phase with spontaneous breaking of flavor and parity and a large hopping phase corresponding to negative quark masses

Wilson Fermions with Four Fermion Interactions

DEFF Research Database (Denmark)

Rantaharju, Jarno; Drach, Vincent; Hietanen, Ari

2015-01-01

We present a lattice study of a four fermion theory, known as Nambu Jona-Lasinio (NJL) theory, via Wilson fermions. Four fermion interactions naturally occur in several extensions of the Standard Model as a low energy parameterisation of a more fundamental theory. In models of dynamical electroweak...

Doença de Wilson em crianças e adolescentes: diagnóstico e tratamento Wilson's disease in children and adolescents: diagnosis and treatment

Directory of Open Access Journals (Sweden)

Stephania de Andrade Sócio

2010-06-01

Pediatric Hepatology Ambulatory of the Hospital das Clínicas of Universidade Federal de Minas Gerais, Brazil, from 1985 to 2008. Data were collected by revision of medical charts and during clinical follow-up. RESULTS: Patients were 2.8 to 15.1 years old, with a mean age of 8.8±0.9 years. The disease main presentation was hepatic (53%, followed by the asymptomatic form, diagnosed by family screening. The Kayser-Fleischer ring was observed in 41% of the patients. The ceruloplasmin was altered in 15 out of 17 patients, and the urinary copper varied from 24 to 1000mcg/24h (median: 184mcg/24h. The treatment was stablished with D-penicillamine in all cases. Slight side effects were observed in five children, with no need to interrupt or change medication. Clinical and laboratory responses to treatment, with normalization of aminotransferases levels, were shown in 14 patients after a median of 10.7 months. Although treated, three patients died (one due to fulminant hepatitis and two due to severe hepatic failure. CONCLUSIONS: Wilson's disease is rare in the pediatric group. In children, the main presentation is the liver disease. The diagnosis can be established by reduced ceruloplasmin levels and elevated copper excretion in the 24-hour urine, but it demands high suspicion level. There are good tolerance and response to medical treatment.

Wilson disease : from clinical to molecular

NARCIS (Netherlands)

Houwen, Roderick Henk Johan

1991-01-01

Wilson disease is an autosomal recessive copper storage disease. It is characterized by an inability of the liver to; excrete copper into bile and to incorporate copper into ceruloplasmin. This results in a gradual accumulation of copper in the liver and subsequently in the brain and other organs,

Kenneth G Wilson (1936–2013)

Indian Academy of Sciences (India)

perceptions of strongly interacting systems – either in particle physics or in condensed matter. The Nobel citation mentions the cryptic term 'renormalization group'. An article elsewhere in this issue ... young research student who had graduated from Harvard University in 1956 – Kenneth Wilson. Gell-Mann suggested that ...

Cygnus Loop supernova remnant: new observations and a framework for understanding its structure and evolution

International Nuclear Information System (INIS)

Hester, J.J.

1985-01-01

New observational data on the Cygnus Loop supernova remnant (SNR) include: (1) a detailed high resolution comparison of x-ray and optical emission for a field in the SE; (2) a map of the [O III] electron temperature for the field previously studied by Hester, Parker, and Dufour (1983); and (3) CCD imagery of the NE limb in the light of four emission lines. A wide range of new and existing observations of the Loop are for the first time interpreted within the context of a single physical description. The Cygnus Loop is not an evaporative SNR evolving into the McKee and Ostriker (1977) ISM, nor are tiny cloudlets necessary to explain its morphology. The data show the Cygnus Loop to be evolving into a medium consisting primarily of an intercloud phase with N 0 approx. 0.1 cm -3 containing clouds with parsec dimensions and N 0 less than or equal to 10 cm -3 . The optical emission arises from extensive sheet like radiative shock fronts driven into the clouds. These fronts locally form the outer boundary of the remnant. The appearance of x-ray emission outside the optical emission on the limbs is due solely to projection effects. The distorted and bumpy shock front is shown to give rise in projection to the filamentary morphology of the remnant

Esclusa Wilson

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Editorial, Equipo

1959-11-01

Full Text Available En la presa Wilson, construida sobre el río Tennessee, ya existía una esclusa y canal que permitía la navegación fluvial por el río. Este rio tiene un curso de difícil navegación en una extensión próxima a la presa, pero la construcción de canales y esclusas ha permitido mejorar estas vías navegables. Estos últimos años ha aumentado tanto la navegación, que la esclusa existente no bastaba para hacer frente al paso de tantas embarcaciones dedicadas al transporte de mercancías que, aún en competencia con él transporte por ferrocarril y carretera, ha llegado a un volumen anual de unos trece millones de toneladas.

Edwin B. Wilson and the rise of mathematical economics in America, 1920-1940

OpenAIRE

Carvajalino, Juan

2017-01-01

In the paper, Edwin B. Wilson's influence on the rise of mathematical economics in America between the 1920s and 1940s is explored. The focus is laid on showing how on the grounds of his foundational ideas about science Wilson worked at the organizational and educational fronts to modernize economics, at this at three levels. First, the paper shows the ways in which around 1930 Wilson was key, at the nationwide level, in the constitution of the first organized community of American mathematic...

Propagating wave in active region-loops, located over the solar disk observed by the Interface Region Imaging Spectrograph

Science.gov (United States)

Zhang, B.; Hou, Y. J.; Zhang, J.

2018-03-01

Aims: We aim to ascertain the physical parameters of a propagating wave over the solar disk detected by the Interface Region Imaging Spectrograph (IRIS). Methods: Using imaging data from the IRIS and the Solar Dynamic Observatory (SDO), we tracked bright spots to determine the parameters of a propagating transverse wave in active region (AR) loops triggered by activation of a filament. Deriving the Doppler velocity of Si IV line from spectral observations of IRIS, we have determined the rotating directions of active region loops which are relevant to the wave. Results: On 2015 December 19, a filament was located on the polarity inversion line of the NOAA AR 12470. The filament was activated and then caused a C1.1 two-ribbon flare. Between the flare ribbons, two rotation motions of a set of bright loops were observed to appear in turn with opposite directions. Following the end of the second rotation, a propagating wave and an associated transverse oscillation were detected in these bright loops. In 1400 Å channel, there was bright material flowing along the loops in a wave-like manner, with a period of 128 s and a mean amplitude of 880 km. For the transverse oscillation, we tracked a given loop and determine the transverse positions of the tracking loop in a limited longitudinal range. In both of 1400 Å and 171 Å channels, approximately four periods are distinguished during the transverse oscillation. The mean period of the oscillation is estimated as 143 s and the displacement amplitude as between 1370 km and 690 km. We interpret these oscillations as a propagating kink wave and obtain its speed of 1400 km s-1. Conclusions: Our observations reveal that a flare associated with filament activation could trigger a kink propagating wave in active region loops over the solar disk. Movies associated to Figs. 1-4 are available at http://https://www.aanda.org

[Wilson disease. A case report and review of the literature].

Science.gov (United States)

Alva-Moncayo, Edith; Castro-Tarín, María; González-Serrano, Adolfo

2011-01-01

Wilson disease is a problem of cuprum metabolism, with recesive autosomic hereditary transmission and a prevalence of one in 30,000 habitants. The cuprum is deposit in a progressive and irreversible way in the liver and encephalus and it is not liberated with quelant treatment. Neurological manifestations are tremor, disartria, extrapiramidal manifestations or distonia. Ophthalmic exploration shows corneal limb with sign of Kayser-Fleischer. a 15-year-old masculine patient with previous hepatitis outbreak in two times. During the last year he presented distonia, bradicinecious, stiffness and indifference with ictericia. Ophthalmological examination reported Kayser-Fleisher rings. Magnetic resonance of brain showed high dense images in lenticular, pallidus globe and caudate nucleus suggestive of Wilson disease. Ceruloplasmin concentration, cuprum in the liver biopsy confirmed the diagnosis. the importance of the case was the hepatic initial manifestations and two years after presented with inexpressive face, and it was considered a psychiatric disease, but the neurological evaluation and the liver biopsy confirmed the diagnosis of Wilson disease.

Observables, skein relations, and tetrahedra in Chern-Simons gauge theory

International Nuclear Information System (INIS)

Martin, S.P.

1990-01-01

The observables in three-dimensional Chern-Simons gauge theory are Wilson lines and Wilson graphs. Skein relations are non-trivial identities between expectation values of distinct Wilson graphs. We discuss various kinds of skein relations and the relationships between them. By comparing different kinds of skein relations, we show how to calculate the expectation value of a general tetrahedral Wilson graph. This is shown to be the last and most difficult step in a systematic procedure for calculating the expectation values of arbitrary Wilson graphs in arbitrary representations of arbitrary gauge groups. (orig.)

Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

Science.gov (United States)

Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

The 3-loop pure singlet heavy flavor contributions to the structure function F{sub 2}(x,Q{sup 2}) and the anomalous dimension

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Behring, A.; Blümlein, J.; De Freitas, A. [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Manteuffel, A. von [PRISMA Cluster of Excellence, Institute of Physics, J. Gutenberg University, D-55099 Mainz (Germany); Schneider, C. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria)

2015-01-15

The pure singlet asymptotic heavy flavor corrections to 3-loop order for the deep-inelastic scattering structure function F{sub 2}(x,Q{sup 2}) and the corresponding transition matrix element A{sub Qq}{sup (3),PS} in the variable flavor number scheme are computed. In Mellin-N space these inclusive quantities depend on generalized harmonic sums. We also recalculate the complete 3-loop pure singlet anomalous dimension for the first time. Numerical results for the Wilson coefficients, the operator matrix element and the contribution to the structure function F{sub 2}(x,Q{sup 2}) are presented.

Simulating QCD at the physical point with Nf=2 Wilson twisted mass fermions at maximal twist

International Nuclear Information System (INIS)

Abdel-Rehim, A.; Alexandrou, C.; Cyprus Univ. Nicosia; Burger, F.

2015-12-01

We present simulations of QCD using N f =2 dynamical Wilson twisted mass lattice QCD with physical value of the pion mass and at one value of the lattice spacing. Such simulations at a∼0.09 fm became possible by adding the clover term to the action. While O(a) improvement is still guaranteed by Wilson twisted mass fermions at maximal twist, the introduction of the clover term reduces O(a 2 ) cutoff effects related to isospin symmetry breaking. We give results for a set of phenomenologically interesting observables like pseudo-scalar masses and decay constants, quark masses and the anomalous magnetic moments of leptons. We mostly find remarkably good agreement with phenomenology, even though we cannot take the continuum and thermodynamic limits.

Symmetries of Ginsparg-Wilson chiral fermions

International Nuclear Information System (INIS)

Mandula, Jeffrey E.

2009-01-01

The group structure of the variant chiral symmetry discovered by Luescher in the Ginsparg-Wilson description of lattice chiral fermions is analyzed. It is shown that the group contains an infinite number of linearly independent symmetry generators, and the Lie algebra is given explicitly. CP is an automorphism of this extended chiral group, and the CP transformation properties of the symmetry generators are found. The group has an infinite-parameter invariant subgroup, and the factor group, whose elements are its cosets, is isomorphic to the continuum chiral symmetry group. Features of the currents associated with these symmetries are discussed, including the fact that some different, noncommuting symmetry generators lead to the same Noether current. These are universal features of lattice chiral fermions based on the Ginsparg-Wilson relation; they occur in the overlap, domain-wall, and perfect-action formulations. In a solvable example, free overlap fermions, these noncanonical elements of lattice chiral symmetry are related to complex energy singularities that violate reflection positivity and impede continuation to Minkowski space.

Determining the closed forms of the O(α3s) anomalous dimensions and Wilson coefficients from Mellin moments by means of computer algebra

International Nuclear Information System (INIS)

Bluemlein, Johannes; Klein, Sebastian; Kauers, Manuel; Schneider, Carsten

2009-02-01

Single scale quantities, as anomalous dimensions and hard scattering cross sections, in renormalizable Quantum Field Theories are found to obey difference equations of finite order in Mellin space. It is often easier to calculate fixed moments for these quantities compared to a direct attempt to derive them in terms of harmonic sums and their generalizations involving the Mellin parameter N. Starting from a sufficiently large number of given moments, we establish linear recurrence relations of lowest possible order with polynomial coefficients of usually high degree. Then these recurrence equations are solved in terms of d'Alembertian solutions where the involved nested sums are represented in optimal nested depth. Given this representation, it is then an easy task to express the result in terms of harmonic sums. In this process we compactify the result such that no algebraic relations occur among the sums involved. We demonstrate the method for the QCD unpolarized anomalous dimensions and massless Wilson coefficients to 3-loop order treating the contributions for individual color coefficients. For the most complicated subproblem 5114 moments were needed in order to produce a recurrence of order 35 whose coefficients have degrees up to 938. About four months of CPU time were needed to establish and solve the recurrences for the anomalous dimensions and Wilson coefficients on a 2 GHz machine requiring less than 10 GB of memory. No algorithm is known yet to provide such a high number of moments for 3-loop quantities. Yet the method presented shows that it is possible to establish and solve recurrences of rather large order and degree, occurring in physics problems, uniquely, fast and reliably with computer algebra. (orig.)

Supergravity couplings to Noncommutative Branes, Open Wilson Lines and Generalised Star Products

International Nuclear Information System (INIS)

Das, S.R.; Trivedi, S.P.

2001-01-01

Noncommutative gauge theories can be constructed from ordinary U(∞) gauge theories in lower dimensions. Using this construction we identify the operators on noncommutative D-branes which couple to linearized supergravity backgrounds, from a knowledge of such couplings to lower dimensional D-branes with no B field. These operators belong to a class of gauge invariant observables involving open Wilson lines. Assuming a DBI form of the coupling we show, to second order in the gauge potential but to all orders of the noncommutativity parameter, that our proposal agrees with the operator obtained in terms of ordinary gauge fields by considering brane actions in backgrounds and then using the Seiberg-Witten map to rewrite this in terms of noncommutative gauge fields. Our result clarify why a certain commutative but non-associative 'generalized star product' appears both in the expansion of the open Wilson line, as well as in string amplitude computations of open string-closed string couplings. We outline how our procedure can be used to obtain operators in the noncommutative theory which are holographically dual to supergravity modes. (author)

Disartria na doença de Wilson: análise de dois casos em fases distintas Dysarthria in Wilson's disease: analysis of two cases in different stages

Directory of Open Access Journals (Sweden)

Natália Casagrande Brabo

2010-06-01

by a visual analogue scale. In addition, the intelligibility was analysed by an orthographic transcription method. Praat 4.4.13 software was used for acoustic analysis. Fundamental frequency, phonatory stability, noise and temporal measures were equally assessed. RESULTS: both patients have a speech characterized by: maximum phonation time reduced, breathiness and strained harsh voice quality, voice stoppages, transient breathiness, increased shimmer and noise-to-harmonics ratio, hypernasality. Oral diadochokinesia, speech rate and intelligibility of speech were reduced. The results suggested that the patient who showed Wilson's disease for longer time showed more acute impairments in most of the analyzed perceptual and acoustic parameters. CONCLUSION: both cases showed similar caracteristics. These features seem to be typical in dysarthric patients with Wilson's disease. However, differences were also observed, and can be related to the disease's evolution.

Epidemiology and introduction to the clinical presentation of Wilson disease.

Science.gov (United States)

Lo, Christine; Bandmann, Oliver

2017-01-01

Our understanding of the epidemiology of Wilson disease has steadily grown since Sternlieb and Scheinberg's first prevalence estimate of 5 per million individuals in 1968. Increasingly sophisticated genetic techniques have led to revised genetic prevalence estimates of 142 per million. Various population isolates exist where the prevalence of Wilson disease is higher still, the highest being 885 per million from within the mountainous region of Rucar in Romania. In Sardinia, where the prevalence of Wilson disease has been calculated at 370 per million births, six mutations account for around 85% of Wilson disease chromosomes identified. Significant variation in the patterns of presentation may however exist, even between individuals carrying the same mutations. At either extremes of presentation are an 8-month-old infant with abnormal liver function tests and individuals diagnosed in their eighth decade of life. Three main patterns of presentation have been recognized - hepatic, neurologic, and psychiatric - prompting their presentation to a diverse range of specialists. Deviations in the family history from the anticipated autosomal-recessive mode of inheritance, with apparent "pseudodominance" and mechanisms of inheritance that include uniparental isodisomy (the inheritance of both chromosomal copies from a single parent), may all further cloud the diagnosis. It can therefore take the efforts of an astute clinician with a high clinical index of suspicion to clinch the diagnosis of this eminently treatable condition. © 2017 Elsevier B.V. All rights reserved.

MRI manifestation of Wilson's disease accompanied with central pontine myelinolysis

International Nuclear Information System (INIS)

Zhang Jingsong; Huan Yi; Chang Yingjuan; Chang Yingjuan; Ge Yali; Zhang Guangyun; Han Yuedong; Zhao Haitao; Yang Chunmin; Yang Yan

2004-01-01

Objective: To discuss MRI manifestation of Wilson's disease accompanied with central pontine myelinolysis (CPM), and to especially detect the value of diffusion-weighted MRI (DWI) in this disease. Methods: Two cases of Wilson's disease accompanied with CPM were performed with sequent MR examination including T 1 WI, T 2 WI, FLAIR, DWI, and contrast-enhanced MRI (CE MRI) by a 1.5 T magnetic resonance system (Philips gyroscan master). Results: Symmetric long T 1 and T 2 signals were found in central pontine region, lenticular nucleus, caudate nucleus, and thalamus. CEMRI showed no apparent enhanced lesions. DWI showed obviously high signal intensities in central pontine region with apparent diffusion coefficient values fluctuated between (100-300) x 10 -6 mm 2 /s while FLAIR images just showed slightly high signal in the same area, which suggested that cytotoxic edema did in fact exist in CPM. Meanwhile, DWI also showed high signals in bilateral lenticular nucleus with apparent diffusion coefficient values fluctuated between (300-600) x 10 -6 mm 2 /s, however, FLAIR images showed heterogeneous high signals and one case presented low DWI signals in bilateral head of caudate nucleus, all these signs might be explained by mixed-changes of cytotoxic edema and vasogenic edema in long period of Wilson's disease. Conclusion: Wilson's disease and CPM have characteristic MRI manifestation and DWI may be a very useful way to confirm a correct diagnosis. (authors)

Topological susceptibility in lattice QCD with unimproved Wilson fermions

International Nuclear Information System (INIS)

Chowdhury, Abhishek; De, Asit K.; De Sarkar, Sangita; Harindranath, A.; Mondal, Santanu; Sarkar, Anwesa; Maiti, Jyotirmoy

2012-01-01

We address a long standing problem regarding topology in lattice simulations of QCD with unimproved Wilson fermions. Earlier attempt with unimproved Wilson fermions at β=5.6 to verify the suppression of topological susceptibility with decreasing quark mass (m q ) was unable to unambiguously confirm the suppression. We carry out systematic calculations for two degenerate flavours at two different lattice spacings (β=5.6 and 5.8). The effects of quark mass, lattice volume and the lattice spacing on the spanning of different topological sectors are presented. We unambiguously demonstrate the suppression of the topological susceptibility with decreasing quark mass, expected from chiral Ward identity and chiral perturbation theory.

The epsilon regime of chiral perturbation theory with Wilson-type fermions

Energy Technology Data Exchange (ETDEWEB)

Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Shindler, A. [Liverpool Univ. (United Kingdom). Theoretical Physics Division

2009-11-15

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory (cPT).We present results for the chiral condensate and the pseudoscalar decay constant obtained with Wilson twisted mass fermions employing two lattice spacings, two different physical volumes and several quark masses. With this set of simulations we make a first attempt to estimate the systematic uncertainties. (orig.)

The epsilon regime of chiral perturbation theory with Wilson-type fermions

International Nuclear Information System (INIS)

Jansen, K.; Shindler, A.

2009-11-01

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory (cPT).We present results for the chiral condensate and the pseudoscalar decay constant obtained with Wilson twisted mass fermions employing two lattice spacings, two different physical volumes and several quark masses. With this set of simulations we make a first attempt to estimate the systematic uncertainties. (orig.)

Beyond the scope of Free-Wilson analysis: building interpretable QSAR models with machine learning algorithms.

Science.gov (United States)

Chen, Hongming; Carlsson, Lars; Eriksson, Mats; Varkonyi, Peter; Norinder, Ulf; Nilsson, Ingemar

2013-06-24

A novel methodology was developed to build Free-Wilson like local QSAR models by combining R-group signatures and the SVM algorithm. Unlike Free-Wilson analysis this method is able to make predictions for compounds with R-groups not present in a training set. Eleven public data sets were chosen as test cases for comparing the performance of our new method with several other traditional modeling strategies, including Free-Wilson analysis. Our results show that the R-group signature SVM models achieve better prediction accuracy compared with Free-Wilson analysis in general. Moreover, the predictions of R-group signature models are also comparable to the models using ECFP6 fingerprints and signatures for the whole compound. Most importantly, R-group contributions to the SVM model can be obtained by calculating the gradient for R-group signatures. For most of the studied data sets, a significant correlation with that of a corresponding Free-Wilson analysis is shown. These results suggest that the R-group contribution can be used to interpret bioactivity data and highlight that the R-group signature based SVM modeling method is as interpretable as Free-Wilson analysis. Hence the signature SVM model can be a useful modeling tool for any drug discovery project.

No increased risk of hepatocellular carcinoma in cirrhosis due to Wilson disease during long-term follow-up

NARCIS (Netherlands)

van Meer, Suzanne; de Man, Robert A.; van den Berg, Aad P.; Houwen, Roderick H. J.; Linn, Francisca H. H.; van Oijen, Martijn G. H.; Siersema, Peter D.; van Erpecum, Karel J.

Background and AimsData on risk of hepatocellular carcinoma (HCC) in patients with Wilson disease are scarce. We determine HCC risk in a well-defined cohort of Wilson patients. MethodsAll patients with a confirmed diagnosis of Wilson disease (Leipzig score4) in three Dutch university referral

Nambu-Jona-Lasinio model with Wilson fermions

DEFF Research Database (Denmark)

Rantaharju, Jarno; Drach, Vincent; Pica, Claudio

2017-01-01

We present a lattice study of a Nambu-Jona-Lasinio (NJL) model using Wilson fermions. Four-fermion interactions are a natural part of several extensions of the Standard Model, appearing as a low-energy description of a more fundamental theory. In models of dynamical electroweak symmetry breaking...

Exact solubility of Chern-Simons theory with compact simple gauge group

International Nuclear Information System (INIS)

Hayashi, Masahito

1993-01-01

We show that vacuum expectation values of Wilson loop operators in (2+1)-dimensional Chern-Simons theory satisfy algebraic equations. Interestingly enough, vacuum expectation values for unknotted Wilson loop operators in any representation of any compact and simple group are exactly computed by solving the equations. So-called 'skein relations', which give us algebraic equations among vacuum expectation values of different Wilson loop operators, are constructed. In our formalism, quantum group symmetry appears naturally. (orig.)

Enforced neutrality and color-flavor unlocking in the three-flavor Polyakov-loop Nambu-Jona-Lasinio model

International Nuclear Information System (INIS)

Abuki, H.; Ciminale, M.; Nardulli, G.; Ruggieri, M.; Gatto, R.

2008-01-01

We study how the charge neutrality affects the phase structure of the three-flavor Polyakov-loop Nambu-Jona-Lasinio (PNJL) model. We point out that, within the conventional PNJL model at finite density, the color neutrality is missing because the Wilson line serves as an external colored field coupled to dynamical quarks. In this paper we heuristically assume that the model may still be applicable. To get color neutrality, one has then to allow nonvanishing color chemical potentials. We study how the quark matter phase diagram in (T,m s 2 /μ)-plane is affected by imposing neutrality and by including the Polyakov-loop dynamics. Although these two effects are correlated in a nonlinear way, the impact of the Polyakov loop turns out to be significant in the T direction, while imposing neutrality brings a remarkable effect in the m s 2 /μ direction. In particular, we find a novel unlocking transition, when the temperature is increased, even in the chiral SU(3) limit. We clarify how and why this is possible once the dynamics of the colored Polyakov loop is taken into account. Also we succeed in giving an analytic expression for T c for the transition from two-flavor pairing (2SC) to unpaired quark matter in the presence of the Polyakov loop.

An interpretation of hydrogen and helium line spectra of the loop prominence observed on November 3, 1973

International Nuclear Information System (INIS)

Kureizumi, Takeshi; Kubota, Jun; Kawaguchi, Ichiro; Tamenaga, Tatsuo; Maeda, Koichiro.

1977-01-01

The H sub(I), He sub(I), and He sub(II) emission lines of the loop prominence observed on November 3, 1973 in the rapidly developing phase are analyzed. The difference in widths of these lines suggests they do not originate in the same volume. The estimated T sub(e) (8000-9000 K) and n sub(e) (-- 2 x 10 12 cm -3 ) in the loop from the Balmer lines do not change appreciably with time everywhere in the loop during our observation (00 sup(h)40 sup(m)-01 sup(h)10 sup(m)UT). The degree of ionization of hydrogen is estimated to be in the range of 0.8 to 1.0. The ionizing mechanisms may be attributed to the UV radiation (lambda<=912A) from the underlying flare region. Local thermodynamic equilibrium (LTE) is approximately established in the excited levels of He sub(I), but the singlet levels are somewhat overpopulated. The UV radiation field (lambda<=504A) from the surrounding coronal condensation is estimated from microwave and X-ray flux measurements of S sub(OLRAD)9. The ionization of He sub(I) (ionization degree 0.1-0.2) is mainly controlled by UV radiation from the coronal condensation. An adequate thread structure model of the loop prominence is suggested. (auth.)

Diverse Functional Properties of Wilson Disease ATP7B Variants

Science.gov (United States)

Huster, Dominik; Kühne, Angelika; Bhattacharjee, Ashima; Raines, Lily; Jantsch, Vanessa; Noe, Johannes; Schirrmeister, Wiebke; Sommerer, Ines; Sabri, Osama; Berr, Frieder; Mössner, Joachim; Stieger, Bruno; Caca, Karel; Lutsenko, Svetlana

2012-01-01

BACKGROUND & AIMS Wilson disease is a severe disorder of copper metabolism caused by mutations in ATP7B, which encodes a copper-transporting adenosine triphosphatase. The disease presents with a variable phenotype that complicates the diagnostic process and treatment. Little is known about the mechanisms that contribute to the different phenotypes of the disease. METHODS We analyzed 28 variants of ATP7B from patients with Wilson disease that affected different functional domains; the gene products were expressed using the baculovirus expression system in Sf9 cells. Protein function was analyzed by measuring catalytic activity and copper (64Cu) transport into vesicles. We studied intracellular localization of variants of ATP7B that had measurable transport activities and were tagged with green fluorescent protein in mammalian cells using confocal laser scanning microscopy. RESULTS Properties of ATP7B variants with pathogenic amino-acid substitution varied greatly even if substitutions were in the same functional domain. Some variants had complete loss of catalytic and transport activity, whereas others lost transport activity but retained phosphor-intermediate formation or had partial losses of activity. In mammalian cells, transport-competent variants differed in stability and subcellular localization. CONCLUSIONS Variants in ATP7B associated with Wilson disease disrupt the protein’s transport activity, result in its mislocalization, and reduce its stability. Single assays are insufficient to accurately predict the effects of ATP7B variants the function of its product and development of Wilson disease. These findings will contribute to our understanding of genotype–phenotype correlation and mechanisms of disease pathogenesis. PMID:22240481

Breeding habitat use by sympatric and allopatric populations of Wilson's Warblers and Yellow Warblers

Science.gov (United States)

Ruth, J.M.; Stanley, T.R.

2002-01-01

We studied Wilson's Warbler (Wilsonia pusilla) and Yellow Warbler (Dendroica petechia) habitat use in allopatric and sympatric populations in the Rocky Mountains of northern Colorado and southeastern Wyoming in order to better understand the different habitat needs and interactions of these two species. Foraging Wilson's Warblers and Yellow Warblers used very similar habitat, both selecting larger, more open shrubs. In spite of similar foraging habitat, comparisons of habitat use by the two species at the sympatric sites yielded no evidence of foraging habitat partitioning or exclusion. There was evidence of nesting habitat partitioning. Wilson's Warblers nested on the ground, with some evidence that they used smaller, more densely stemmed shrubs under which to nest. Yellow Warblers are shrub nesters and selected larger, more open shrubs in which to nest. Results provide no evidence that Yellow Warblers can be blamed for population declines in Wilson's Warblers.

The Split Nucleus of Comet Wilson (C/1986 P1 = 1987 VII).

Science.gov (United States)

Meech, Karen J.; Knopp, Graham P.; Farnham, Tony L.; Green, Daniel

1995-07-01

We present CCD observations of Comet Wilson (C/1986 P1 = 1987 VII) from 26 nights during the time period 1986 October to 1991 February, which brackets perihelion, During the observing run of 1988 February, the comet was observed to have split into two fragments. Our broadband CCD photometry, along with photometry from the International Cometary Quarterly, shows a steady decline in brightness of Comet Wilson post-perihelion, with an outburst between heliocentric distances r = 2.8 and 3.3 AU during 1987 October and November. By r ≈ 7 AU, the fragment had faded with respect to the parent and was no longer centrally condensed. A brightness limit of mR ≈ 25, when the comet was at r = 12.65 AU, constrains the primary nucleus to have a maximum radius between 5 and 7 km, assuming an albedo of 0.04. The accuracy of direct orbital solutions for the parent body and fragment to determine the time of splitting was limited by the presence of significant nongravitational forces and the limited fragment orbital coverage. We used the relative position of the fragment with respect to the parent to calculate a time of splitting which was consistent with the time of the observed outburst. We discuss the possible causes of the splitting. The coma of Comet Wilson was observed to have a surface-brightness profile which fell off as p-1 (characteristic of a canonical steady-state coma under the influence of radiation pressure) for all of the data with the exception of the data taken during 1987 November when the gradient was p-1.3 . This steeper slope was probably caused by the injection of new material into the coma during the outburst. During 1986 October, there was a break in the surface-brightness profile slope which may be interpreted as the distance at which grains are swept into the tail. The profiles suggested grain velocities of a few x 10 2 to 10 m sec -1 for grains between 1 and a few hundred micrometers. Finson-Probstein dust modeling showed that ejection of grains began

Notes on winter feeding behavior and molt in Wilson's phalaropes

Science.gov (United States)

Burger, J.; Howe, M.

1975-01-01

Wilson's Phalaropes, Steganopus tricolor, migrate in late summer from the prairie regions of North America to their wintering grounds in the highlands of Peru and the inland and coastal waters of Chile, Bolivia, Paraguay, Uruguay, and Argentina (Holmes 1939, Meyer de Schauensee 1970). Reports on these birds from their wintering habitat are few. This paper describes numbers, feeding behavior, and molt of Wilson's Phalaropes wintering in a freshwater marsh in central Argentina. Fieldwork in Argentina was conducted by the senior author. The junior author analyzed molt patterns of birds collected there and added data he collected in North Dakota in 1968 and 1969.

The Modern First Lady and Public Policy: From Edith Wilson through Hillary Rodham Clinton.

Science.gov (United States)

Black, Allida M.

2001-01-01

Discusses the role in and influence on public policy of twentieth century First Ladies including Edith Roosevelt, Helen Taft, Ellen Wilson, Edith Wilson, Florence Harding, Lou Henry Hoover, Eleanor Roosevelt, Jacqueline Kennedy, Lady Bird Johnson, Rosalynn Carter, Nancy Reagan, Barbara Bush, and Hillary Rodham Clinton. (CMK)

Inhibitory rTMS applied on somatosensory cortex in Wilson's disease patients with hand dystonia.

Science.gov (United States)

Lozeron, Pierre; Poujois, Aurélia; Meppiel, Elodie; Masmoudi, Sana; Magnan, Thierry Peron; Vicaut, Eric; Houdart, Emmanuel; Guichard, Jean-Pierre; Trocello, Jean-Marc; Woimant, France; Kubis, Nathalie

2017-10-01

Hand dystonia is a common complication of Wilson's disease (WD), responsible for handwriting difficulties and disability. Alteration of sensorimotor integration and overactivity of the somatosensory cortex have been demonstrated in dystonia. This study investigated the immediate after effect of an inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the somatosensory cortex on the writing function in WD patients with hand dystonia. We performed a pilot prospective randomized double-blind sham-controlled crossover rTMS study. A 20-min 1-Hz rTMS session, stereotaxically guided, was applied over the left somatosensory cortex in 13 WD patients with right dystonic writer's cramp. After 3 days, each patient was crossed-over to the alternative treatment. Patients were clinically evaluated before and immediately after each rTMS session with the Unified Wilson's Disease rating scale (UWDRS), the Writers' Cramp Rating Scale (WCRS), a specifically designed scale for handwriting difficulties in Wilson's disease patients (FAR, flow, accuracy, and rhythmicity evaluation), and a visual analog scale (VAS) for handwriting discomfort. No significant change in UWDRS, WCRS, VAS, or FAR scores was observed in patients treated with somatosensory inhibitory rTMS compared to the sham protocol. The FAR negatively correlated with UWDRS (r = -0.6; P = 0.02), but not with the WCRS score, disease duration, MRI diffusion lesions, or with atrophy scores. In our experimental conditions, a single inhibitory rTMS session applied over somatosensory cortex did not improve dystonic writer cramp in WD patients.

Importance and significance of liver echotomography in Wilson disease childhood

Energy Technology Data Exchange (ETDEWEB)

Corda, R; Nurchi, A M; Corrias, A; Corda, A; Giagheddu, M; Campisi, G

1987-01-01

We studed the hepatic echography patterns of young patients suffering from Wilson's Disease and compared these with results obtained from laboratory tests and parenchymal biopsy. Eight children, aged between 5 and 12 years (4 males and 4 females), were examined. The symptomatological pattern showed hepatomegaly and liver dysfunction with undetectable or very low serum ceruloplasmine levels and typical aspects of organic copper metabolism. In 50% of cases echography revealed a variable hyperreflection of the whole parenchyma, in connection with the presence of steatosis and aspects of intralobular inflammation. Fine and linear echoes were present, in 50% of the cases, with varying degrees of brightness, which was associated with the presence of fibrotic component or copper granules. Further echographic modifications were less frequent. Echography in close relatives of our patients was observed hepatomegaly and alteration of hepatic reflection associated with fibrotic component. In the evaluation of liver involvement in Wilson's Disease, these findings show that echotomography, when compared to hepatic biopsy, is less efficient in detecting different types of hepatic lesion but on a clinical basis it offers the possibility of evaluating their presence and gravity during the evolutive phase of the illness. This examination, unlike other methods, is completely non invasive; it may easily be repeated and may, in the future, come to be used as more precise diagnostic complement. 30 refs.

OBSERVING THE FINE STRUCTURE OF LOOPS THROUGH HIGH-RESOLUTION SPECTROSCOPIC OBSERVATIONS OF CORONAL RAIN WITH THE CRISP INSTRUMENT AT THE SWEDISH SOLAR TELESCOPE

International Nuclear Information System (INIS)

Antolin, P.; Rouppe van der Voort, L.

2012-01-01

Observed in cool chromospheric lines, such as Hα or Ca II H, coronal rain corresponds to cool and dense plasma falling from coronal heights. Considered as a peculiar sporadic phenomenon of active regions, it has not received much attention since its discovery more than 40 years ago. Yet, it has been shown recently that a close relationship exists between this phenomenon and the coronal heating mechanism. Indeed, numerical simulations have shown that this phenomenon is most likely due to a loss of thermal equilibrium ensuing from a heating mechanism acting mostly toward the footpoints of loops. We present here one of the first high-resolution spectroscopic observations of coronal rain, performed with the CRisp Imaging Spectro Polarimeter (CRISP) instrument at the Swedish Solar Telescope. This work constitutes the first attempt to assess the importance of coronal rain in the understanding of the coronal magnetic field in active regions. With the present resolution, coronal rain is observed to literally invade the entire field of view. A large statistical set is obtained in which dynamics (total velocities and accelerations), shapes (lengths and widths), trajectories (angles of fall of the blobs), and thermodynamic properties (temperatures) of the condensations are derived. Specifically, we find that coronal rain is composed of small and dense chromospheric cores with average widths and lengths of ∼310 km and ∼710 km, respectively, average temperatures below 7000 K, displaying a broad distribution of falling speeds with an average of ∼70 km s –1 , and accelerations largely below the effective gravity along loops. Through estimates of the ion-neutral coupling in the blobs we show that coronal rain acts as a tracer of the coronal magnetic field, thus supporting the multi-strand loop scenario, and acts as a probe of the local thermodynamic conditions in loops. We further elucidate its potential in coronal heating. We find that the cooling in neighboring strands

Determining the closed forms of the O({alpha}{sup 3}{sub s}) anomalous dimensions and Wilson coefficients from Mellin moments by means of computer algebra

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, Johannes; Klein, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Kauers, Manuel; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation

2009-02-15

Single scale quantities, as anomalous dimensions and hard scattering cross sections, in renormalizable Quantum Field Theories are found to obey difference equations of finite order in Mellin space. It is often easier to calculate fixed moments for these quantities compared to a direct attempt to derive them in terms of harmonic sums and their generalizations involving the Mellin parameter N. Starting from a sufficiently large number of given moments, we establish linear recurrence relations of lowest possible order with polynomial coefficients of usually high degree. Then these recurrence equations are solved in terms of d'Alembertian solutions where the involved nested sums are represented in optimal nested depth. Given this representation, it is then an easy task to express the result in terms of harmonic sums. In this process we compactify the result such that no algebraic relations occur among the sums involved. We demonstrate the method for the QCD unpolarized anomalous dimensions and massless Wilson coefficients to 3-loop order treating the contributions for individual color coefficients. For the most complicated subproblem 5114 moments were needed in order to produce a recurrence of order 35 whose coefficients have degrees up to 938. About four months of CPU time were needed to establish and solve the recurrences for the anomalous dimensions and Wilson coefficients on a 2 GHz machine requiring less than 10 GB of memory. No algorithm is known yet to provide such a high number of moments for 3-loop quantities. Yet the method presented shows that it is possible to establish and solve recurrences of rather large order and degree, occurring in physics problems, uniquely, fast and reliably with computer algebra. (orig.)

An Approach to Enforcing Clark-Wilson Model in Role-based Access Control Model

Institute of Scientific and Technical Information of China (English)

LIANGBin; SHIWenchang; SUNYufang; SUNBo

2004-01-01

Using one security model to enforce another is a prospective solution to multi-policy support. In this paper, an approach to the enforcing Clark-Wilson data integrity model in the Role-based access control (RBAC) model is proposed. An enforcement construction with great feasibility is presented. In this construction, a direct way to enforce the Clark-Wilson model is provided, the corresponding relations among users, transformation procedures, and constrained data items are strengthened; the concepts of task and subtask are introduced to enhance the support to least-privilege. The proposed approach widens the applicability of RBAC. The theoretical foundation for adopting Clark-Wilson model in a RBAC system with small cost is offered to meet the requirements of multi-policy support and policy flexibility.

Partially quenched lattice QCD with two degenerate dynamical light Wilson quarks

International Nuclear Information System (INIS)

De, Asit K.; Harindranath, A.; Maiti, Jyotirmoy

2006-01-01

We present our results of numerical studies of partially quenched latticed QCD with two degenerate flavors of dynamical quarks. Gauge configurations are generated with Wilson gauge action and tadpole improved Wilson fermions at β = 5.6 and K sea = 0.155, 0.156, 0.157 and 0.158. Suitably smeared gauge configurations are used to calculate the static interquark potential in order to set the physical scale. Mesonic propagators are calculated at above mentioned four different values of K val for each K sea . We present results for pion and rho masses. (author)

Middle-aged heterozygous carriers of Wilson's disease do not ...

Indian Academy of Sciences (India)

957 Warsaw, Poland. 2Medical University of Warsaw, Department of Experimental and Clinical Pharmacology, 00–325 Warsaw, Poland. Introduction. Wilson disease (WD) is an autosomal recessive disor- der of copper (Cu) metabolism (OMIM ...

The value-adding CFO: an interview with Disney's Gary Wilson. Interview by Geraldine E. Willigan.

Science.gov (United States)

Wilson, G

1990-01-01

Financing a company is more complex than ever-and more important to its economic success. The demands on a CFO are tremendous. Optimizing capital costs requires an unprecedented level of technical sophistication. Yet the best CFOs today are not mere technicians. They are also strategists and innovators. Gary Wilson exemplifies the new CFO. In his 5 years as executive vice president and CFO of the Walt Disney Company and his 12 years at Marriott Corporation, he has shown how the finance function can add value-not just account for it. How does a CFO create value for shareholders? "Just like all the great marketing and operating executives," Wilson says, "by being creative." To Wilson, being creative means rethinking assumptions and finding clever ways to achieve financial and strategic goals. Some of Wilson's innovative deal making-like the off-balance-sheet financing he used at Marriott-is well known. At Marriott, he discovered the power of separating the ownership of an asset from its control. Marriott's strength was in operations, yet the company had a great deal of money tied up in real estate. Growth would require even more investment in real estate. Wilson's solution was to sell the hotels-in effect, removing them and the debt used to finance them from the balance sheet-and contract to operate them. In this interview, Wilson gives his view of the role of finance in today's corporation and explains the thinking behind some of the successful deals he has engineered-including Disney's Silver Screen movie-making partnerships and Euro Disneyland.

Hypopituitarism Presenting as Adrenal Insufficiency and Hypothyroidism in a Patient with Wilson's Disease: a Case Report.

Science.gov (United States)

Lee, Hae Won; Kang, Jin Du; Yeo, Chang Woo; Yoon, Sung Woon; Lee, Kwang Jae; Choi, Mun Ki

2016-08-01

Wilson's disease typically presents symptoms associated with liver damage or neuropsychiatric disturbances, while endocrinologic abnormalities are rare. We report an unprecedented case of hypopituitarism in a patient with Wilson's disease. A 40-year-old woman presented with depression, general weakness and anorexia. Laboratory tests and imaging studies were compatible with liver cirrhosis due to Wilson's disease. Basal hormone levels and pituitary function tests indicated secondary hypothyroidism and adrenal insufficiency due to hypopituitarism. Brain MRI showed T2 hyperintense signals in both basal ganglia and midbrain but the pituitary imaging was normal. She is currently receiving chelation therapy along with thyroid hormone and steroid replacement. There may be a relationship between Wilson's disease and hypopituitarism. Copper deposition or secondary neuronal damage in the pituitary may be a possible explanation for this theory.

Uncovering the triple omeron vertex from Wilson line formalism

International Nuclear Information System (INIS)

Chirilli, G. A.; Szymanowski, L.; Wallon, S.

2011-01-01

We compute the triple omeron vertex from the Wilson line formalism, including both planar and nonplanar contributions, and get perfect agreement with the result obtained in the Extended Generalized Logarithmic Approximation based on Reggeon calculus.

Geometry of Hα active region loops observed on the solar disk

International Nuclear Information System (INIS)

Chuan-le, C.; Loughhead, R.E.

1983-01-01

Plasma loops are the dominant structures in the higher levels of the Sun's atmosphere above active regions. A geometrical technique has been used to reconstruct the true shapes of two large dark loops of the type ordinarily found in active regions in the absence of flares

"Mens Sana in Corpore Sano": Human Values in Thomas Wilson's "The Arte of Rhetorique."

Science.gov (United States)

Luehring, Janet

In 1553 the work that is touted as the first complete book written in English on rhetoric was published, Thomas Wilson's "Arte of Rhetorique." It became so popular it enjoyed eight printings within its century. Wilson was not a person to translate and read just for knowledge; he believed that knowledge should be imparted to the general…

SPLPKG WFCMPR WFAPPX, Wilson-Fowler Spline Generator for Computer Aided Design And Manufacturing (CAD/CAM) Systems

International Nuclear Information System (INIS)

Fletcher, S.K.

2002-01-01

1 - Description of program or function: The three programs SPLPKG, WFCMPR, and WFAPPX provide the capability for interactively generating, comparing and approximating Wilson-Fowler Splines. The Wilson-Fowler spline is widely used in Computer Aided Design and Manufacturing (CAD/CAM) systems. It is favored for many applications because it produces a smooth, low curvature fit to planar data points. Program SPLPKG generates a Wilson-Fowler spline passing through given nodes (with given end conditions) and also generates a piecewise linear approximation to that spline within a user-defined tolerance. The program may be used to generate a 'desired' spline against which to compare other Splines generated by CAD/CAM systems. It may also be used to generate an acceptable approximation to a desired spline in the event that an acceptable spline cannot be generated by the receiving CAD/CAM system. SPLPKG writes an IGES file of points evaluated on the spline and/or a file containing the spline description. Program WFCMPR computes the maximum difference between two Wilson-Fowler Splines and may be used to verify the spline recomputed by a receiving system. It compares two Wilson-Fowler Splines with common nodes and reports the maximum distance between curves (measured perpendicular to segments) and the maximum difference of their tangents (or normals), both computed along the entire length of the Splines. Program WFAPPX computes the maximum difference between a Wilson- Fowler spline and a piecewise linear curve. It may be used to accept or reject a proposed approximation to a desired Wilson-Fowler spline, even if the origin of the approximation is unknown. The maximum deviation between these two curves, and the parameter value on the spline where it occurs are reported. 2 - Restrictions on the complexity of the problem - Maxima of: 1600 evaluation points (SPLPKG), 1000 evaluation points (WFAPPX), 1000 linear curve breakpoints (WFAPPX), 100 spline Nodes

The Wilson-Bappu effect of the MgII k line - dependence on stellar temperature, activity and metallicity

DEFF Research Database (Denmark)

Elgaroy, O.; Engvold, O.; Lund, Niels

1999-01-01

widths around the regression lines. The sample contains slowly rotating stars of different activity levels and is suitable for investigations of a possible relation between line width and stellar activity. A difference in behavior between dwarfs and giants (and supergiants) of spectral class K seems......The Wilson-Bappu effect is investigated using accurate absolute magnitudes of 65 stars obtained through early release of data from the Hipparcos satellite together with MgII k fine widths determined from high resolution spectra observed with the International Ultraviolet Explorer (IUE) observatory....... Stars of spectral classes F, G, K and M and luminosity classes I-V are represented in the sample. Wilson-Bappu relations for the Mg II k line for stars of different temperatures i.e. spectral classes are determined. The relation varies with spectral class and there is a significant scatter of the line...

A search for the millimetre lines of HCN in Comets Wilson 1987 VII and Machholz 1988 XV

Science.gov (United States)

Crouvisier, J.; Despois, D.; Bockelee-Morvan, D.; Gerard, E.; Paubert, G.; Johansson, L. E. B.; Ekelund, L.; Winnberg, A.; Ge, W.; Irvine, W. M.; Kinzel, W. M.; Schloerb, F. P.

1990-08-01

The J(1-0) lines of HCN at 89 GHz were searched for in Comet Wilson 1987 VII, with the FCRAO, the SEST and the IRAM radio telescopes between February and June 1987. There was no firm detection, but significant upper limits were obtained, which put severe constraints on the HCN production rate in that comet. A direct comparison with the observations of P/Halley suggests that the HCN abundance relative to water might be smaller in Comet Wilson by at least a factor of two. The J(1-0) and J(3-2) lines of HCN at 89 and 266 GHz were searched for in Comet Machholz 1988 XV when it was close to perihelion at 0.17 AU from the sun. There was no detection. At that moment, the comet was probably no longer active.

Wilson and Gisvold's textbook of organic medicinal and pharmaceutical chemistry

National Research Council Canada - National Science Library

Wilson, Charles Owens; Beale, John Marlowe; Block, John H

2011-01-01

"For over half a century, Wilson and Gisvold's Textbook of Organic Medicinal and Pharmaceutical Chemistry has served the discipline of medicinal chemistry for both graduate and undergraduate pharmacy...

Lattice QCD at finite temperature with Wilson fermions

International Nuclear Information System (INIS)

Pinke, Christopher

2014-01-01

The subatomic world is governed by the strong interactions of quarks and gluons, described by Quantum Chromodynamics (QCD). Quarks experience confinement into colour-less objects, i.e. they can not be observed as free particles. Under extreme conditions such as high temperature or high density, this constraint softens and a transition to a phase where quarks and gluons are quasi-free particles (Quark-Gluon-Plasma) can occur. This environment resembles the conditions prevailing during the early stages of the universe shortly after the Big Bang. The phase diagram of QCD is under investigation in current and future collider experiments, for example at the Large Hadron Collider (LHC) or at the Facility for Antiproton and Ion Research (FAIR). Due to the strength of the strong interactions in the energy regime of interest, analytic methods can not be applied rigorously. The only tool to study QCD from first principles is given by simulations of its discretised version, Lattice QCD (LQCD). These simulations are in the high-performance computing area, hence, the numerical aspects of LQCD are a vital part in this field of research. In recent years, Graphic Processing Units (GPUs) have been incorporated in these simulations as they are a standard tool for general purpose calculations today. In the course of this thesis, the LQCD application CL 2 QCD has been developed, which allows for simulations on GPUs as well as on traditional CPUs, as it is based on OpenCL. CL 2 QCD constitutes the first application for Wilson type fermions in OpenCL. It provides excellent performance and has been applied in physics studies presented in this thesis. The investigation of the QCD phase diagram is hampered by the notorious sign-problem, which restricts current simulation algorithms to small values of the chemical potential. Theoretically, studying unphysical parameter ranges allows for constraints on the phase diagram. Of utmost importance is the clarification of the order of the finite

Sequence-structure relationships in RNA loops: establishing the basis for loop homology modeling.

Science.gov (United States)

Schudoma, Christian; May, Patrick; Nikiforova, Viktoria; Walther, Dirk

2010-01-01

The specific function of RNA molecules frequently resides in their seemingly unstructured loop regions. We performed a systematic analysis of RNA loops extracted from experimentally determined three-dimensional structures of RNA molecules. A comprehensive loop-structure data set was created and organized into distinct clusters based on structural and sequence similarity. We detected clear evidence of the hallmark of homology present in the sequence-structure relationships in loops. Loops differing by structures. Thus, our results support the application of homology modeling for RNA loop model building. We established a threshold that may guide the sequence divergence-based selection of template structures for RNA loop homology modeling. Of all possible sequences that are, under the assumption of isosteric relationships, theoretically compatible with actual sequences observed in RNA structures, only a small fraction is contained in the Rfam database of RNA sequences and classes implying that the actual RNA loop space may consist of a limited number of unique loop structures and conserved sequences. The loop-structure data sets are made available via an online database, RLooM. RLooM also offers functionalities for the modeling of RNA loop structures in support of RNA engineering and design efforts.

An experimental study of dislocation loop nucleation

International Nuclear Information System (INIS)

Bounaud, J.Y.; Leteurtre, J.

1975-01-01

The nucleation of dislocation loops is experimentally studied by observing the demixion of the Burgers vectors of dislocation loops nucleated in copper whiskers irradiated in flexion by fission fragments at room temperature. The demixion of Burgers vectors is observed by the dimensional effects of dislocation loops: after irradiation, the applied stress is removed; the whisker shows a residual strain that is due to loops because, after an annealing treatment to evaporate dislocation loops, each whisker recovers its initial straight shape. Everywhere along the whisker, the radius of curvature is measured and plotted vs the max. applied stress. Estimations of the interstitial and vacancy dislocation loop nuclei are derived [fr

Chromospheric scaling laws, width-luminosity correlations, and the Wilson-Bappu effect

International Nuclear Information System (INIS)

Ayres, T.R.

1979-01-01

Simple scaling laws are developed to explain the thickness and mean electron density of late-type stellar chromospheres in an effort to understand why the emission cores of effectively thick resonance lines such as Ca II H and K broaden with increasing stellar luminosity (the Wilson-Bappu effect). It is shown that stellar chromospheres become thicker in mass column density as stellar gravity g decreases and that the mean chromospheric electric density n/sub e/ decreases if the chromospheric heating dF/dm is constant with height and if the total heating F/sup tot/ is independent of g. It is also shown that chromospheres becomes thicker and the mean electron density becomes larger than the total chromospheric heating increases. The predicted behavior of the K 1 minimum separation and full width at half-maximum of the Ca II emission core (W 0 ) based on the derived scaling laws agree quantitatively with the observed correlations of these widths with fundamental stellar parameters, particularly surface gravity. In addition, the predicted behavior of the K 2 peak separation and base emission width with increasing chromospheric heating is consistent with the behavior of the Ca II emission core shapes in solar plages. The analytical arguments suggest that the Wilson-Bappu effect is largely a consequence of hydrostatic equilibrium rather than chromospheric dynamics

Transformation of a Free-Wilson matrix into Fourier coefficients

Czech Academy of Sciences Publication Activity Database

Holík, M.; Halámek, Josef

2002-01-01

Roč. 20, - (2002), s. 422 - 428 ISSN 0931-8771 Institutional research plan: CEZ:AV0Z2065902 Keywords : Free-Wilson matrix * Fourier transform * multivariate regression Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.558, year: 2002

Lifebox | Wilson | Southern African Journal of Anaesthesia and ...

African Journals Online (AJOL)

Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 18, No 1 (2012) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Lifebox. IH Wilson. Abstract.

Wilson's Disease: Expect the Unexpected.

Science.gov (United States)

El Imad, Talal; Al Moussawi, Hassan; Haddad, Fady G; Felix, Richard; Mulrooney, Stephen M

2018-02-08

A 64-year-old woman, presented with abdominal distention, jaundice and resting tremor, was found to have liver injury and abnormal liver enzymes. A computed tomography (CT) scan of the abdomen and pelvis showed abdominopelvic ascites and signs of liver cirrhosis. An extensive liver disease workup was performed and came back negative; therefore, a liver biopsy was obtained and showed evidence of cirrhosis with elevated liver copper consistent with Wilson's disease (WD). We report a unique case of late-onset WD in which the ceruloplasmin level and 24-h urinary copper excretion were all normal.

Revisiting the dilatation operator of the Wilson-Fisher fixed point

Energy Technology Data Exchange (ETDEWEB)

Liendo, Pedro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

2017-01-15

We revisit the order ε dilatation operator of the Wilson-Fisher fixed point obtained by Kehrein, Pismak, and Wegner in light of recent results in conformal field theory. Our approach is algebraic and based only on symmetry principles. The starting point of our analysis is that the first correction to the dilatation operator is a conformal invariant, which implies that its form is fixed up to an infinite set of coefficients associated with the scaling dimensions of higher-spin currents. These coefficients can be fixed using well-known perturbative results, however, they were recently re-obtained using CFT arguments without relying on perturbation theory. Our analysis then implies that all order-ε scaling dimensions of the Wilson-Fisher fixed point can be fixed by symmetry.

Woodrow Wilson's hidden stroke of 1919: the impact of patient-physician confidentiality on United States foreign policy.

Science.gov (United States)

Menger, Richard P; Storey, Christopher M; Guthikonda, Bharat; Missios, Symeon; Nanda, Anil; Cooper, John M

2015-07-01

World War I catapulted the United States from traditional isolationism to international involvement in a major European conflict. Woodrow Wilson envisaged a permanent American imprint on democracy in world affairs through participation in the League of Nations. Amid these defining events, Wilson suffered a major ischemic stroke on October 2, 1919, which left him incapacitated. What was probably his fourth and most devastating stroke was diagnosed and treated by his friend and personal physician, Admiral Cary Grayson. Grayson, who had tremendous personal and professional loyalty to Wilson, kept the severity of the stroke hidden from Congress, the American people, and even the president himself. During a cabinet briefing, Grayson formally refused to sign a document of disability and was reluctant to address the subject of presidential succession. Wilson was essentially incapacitated and hemiplegic, yet he remained an active president and all messages were relayed directly through his wife, Edith. Patient-physician confidentiality superseded national security amid the backdrop of friendship and political power on the eve of a pivotal juncture in the history of American foreign policy. It was in part because of the absence of Woodrow Wilson's vocal and unwavering support that the United States did not join the League of Nations and distanced itself from the international stage. The League of Nations would later prove powerless without American support and was unable to thwart the rise and advance of Adolf Hitler. Only after World War II did the United States assume its global leadership role and realize Wilson's visionary, yet contentious, groundwork for a Pax Americana. The authors describe Woodrow Wilson's stroke, the historical implications of his health decline, and its impact on United States foreign policy.

Can we observe open loop transfer functions in a stochastic feedback system ?

International Nuclear Information System (INIS)

Kishida, Kuniharu; Suda, Nobuhide.

1991-01-01

There are two kinds of problems concerning open loop and closed loop transfer functions in a feedback system. One is a problem even in the deterministic case, and the other is in the stochastic case. In the deterministic case it is guaranteed under a necessary and sufficient condition that total sum of degrees of sub-transfer functions coincides to the degree of the total system. In the stochastic case a systematic understanding of a physical state model, a theoretical innovation model and a data-oriented innovation model is indispensable for determination of open loop transfer functions from time series data. Undesirable factors appear in determination of open loop transfer functions, since a transfer function matrix from input noises to output variables has a redundancy factor of diagonal matrix. (author)

Genotype-phenotype correlations in a mountain population community with high prevalence of Wilson's disease: genetic and clinical homogeneity.

Directory of Open Access Journals (Sweden)

Relu Cocoş

Full Text Available Wilson's disease is an autosomal recessive disorder caused by more than 500 mutations in ATP7B gene presenting considerably clinical manifestations heterogeneity even in patients with a particular mutation. Previous findings suggested a potential role of additional genetic modifiers and environment factors on phenotypic expression among the affected patients. We conducted clinical and genetic investigations to perform genotype-phenotype correlation in two large families living in a socio-culturally isolated community with the highest prevalence of Wilson's disease ever reported of 1 ∶ 1130. Sequencing of ATP7B gene in seven affected individuals and 43 family members identified a common compound heterozygous genotype, H1069Q/M769H-fs, in five symptomatic and two asymptomatic patients and detected the presence of two out of seven identified single nucleotide polymorphisms in all affected patients. Symptomatic patients had similar clinical phenotype and age at onset (18 ± 1 years showing dysarthria and dysphagia as common clinical features at the time of diagnosis. Moreover, all symptomatic patients presented Kayser-Fleischer rings and lack of dystonia accompanied by unfavourable clinical outcomes. Our findings add value for understanding of genotype-phenotype correlations in Wilson's disease based on a multifamily study in an isolated population with high extent of genetic and environmental homogeneity as opposed to majority of reports. We observed an equal influence of presumed other genetic modifiers and environmental factors on clinical presentation and age at onset of Wilson's disease in patients with a particular genotype. These data provide valuable inferences that could be applied for predicting clinical management in asymptomatic patients in such communities.

Superconformal quantum field theories in string. Gauge theory dualities

Energy Technology Data Exchange (ETDEWEB)

Wiegandt, Konstantin

2012-08-14

In this thesis aspects of superconformal field theories that are of interest in the so-called AdS/CFT correspondence are investigated. The AdS/CFT correspondence states a duality between string theories living on Anti-de Sitter space and superconformal quantum field theories in Minkowski space. In the context of the AdS/CFT correspondence the so-called Wilson loop/amplitude duality was discovered, stating the equality of the finite parts of n-gluon MHV amplitudes and n-sided lightlike polygonal Wilson loops in N=4 supersymmetric Yang-Mills (SYM) theory. It is the subject of the first part of this thesis to investigate the Wilson loop side of a possible similar duality in N=6 superconformal Chern-Simons matter (ABJM) theory. The main result is, that the expectation value of n-sided lightlike polygonal Wilson loops vanishes at one-loop order and at two-loop order is identical in its functional form to the Wilson loop in N=4 SYM theory at one-loop order. Furthermore, an anomalous conformal Ward identity for Wilson loops in Chern-Simons theory is derived. Related developments and symmetries of amplitudes and correlators in ABJM theory are discussed as well. In the second part of this thesis we calculate three-point functions of two protected operators and one twist-two operator with arbitrary even spin j in N=4 SYM theory. In order to carry out the calculations, the indices of the spin j operator are projected to the light-cone and the correlator is evaluated in a soft-limit where the momentum coming in at the spin j operator becomes zero. This limit largely simplifies the perturbative calculation, since all three-point diagrams effectively reduce to two-point diagrams and the dependence on the one-loop mixing matrix drops out completely. The result is in agreement with the analysis of the operator product expansion of four-point functions of half-BPS operators by Dolan and Osborn in 2004.

Superconformal quantum field theories in string. Gauge theory dualities

International Nuclear Information System (INIS)

Wiegandt, Konstantin

2012-01-01

In this thesis aspects of superconformal field theories that are of interest in the so-called AdS/CFT correspondence are investigated. The AdS/CFT correspondence states a duality between string theories living on Anti-de Sitter space and superconformal quantum field theories in Minkowski space. In the context of the AdS/CFT correspondence the so-called Wilson loop/amplitude duality was discovered, stating the equality of the finite parts of n-gluon MHV amplitudes and n-sided lightlike polygonal Wilson loops in N=4 supersymmetric Yang-Mills (SYM) theory. It is the subject of the first part of this thesis to investigate the Wilson loop side of a possible similar duality in N=6 superconformal Chern-Simons matter (ABJM) theory. The main result is, that the expectation value of n-sided lightlike polygonal Wilson loops vanishes at one-loop order and at two-loop order is identical in its functional form to the Wilson loop in N=4 SYM theory at one-loop order. Furthermore, an anomalous conformal Ward identity for Wilson loops in Chern-Simons theory is derived. Related developments and symmetries of amplitudes and correlators in ABJM theory are discussed as well. In the second part of this thesis we calculate three-point functions of two protected operators and one twist-two operator with arbitrary even spin j in N=4 SYM theory. In order to carry out the calculations, the indices of the spin j operator are projected to the light-cone and the correlator is evaluated in a soft-limit where the momentum coming in at the spin j operator becomes zero. This limit largely simplifies the perturbative calculation, since all three-point diagrams effectively reduce to two-point diagrams and the dependence on the one-loop mixing matrix drops out completely. The result is in agreement with the analysis of the operator product expansion of four-point functions of half-BPS operators by Dolan and Osborn in 2004.

The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F2(x,Q2 and transversity

Directory of Open Access Journals (Sweden)

J. Ablinger

2014-09-01

Full Text Available We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F2(x,Q2 in the asymptotic region Q2≫m2 and the associated operator matrix element Aqq,Q(3,NS(N to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(NF and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F2(x,Q2.

The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F2(x,Q2) and transversity

International Nuclear Information System (INIS)

Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von

2014-06-01

We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F 2 (x,Q 2 ) in the asymptotic region Q 2 >>m 2 and the associated operator matrix element A (3),NS qq,Q (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated to the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(N F ) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F 2 (x,Q 2 ).

The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F2(x,Q2) and transversity

International Nuclear Information System (INIS)

Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; Manteuffel, A. von; Round, M.; Schneider, C.; Wißbrock, F.

2014-01-01

We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F 2 (x,Q 2 ) in the asymptotic region Q 2 ≫m 2 and the associated operator matrix element A qq,Q (3),NS (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(N F ) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F 2 (x,Q 2 )

50 CFR 20.104 - Seasons, limits, and shooting hours for rails, woodcock, and common (Wilson's) snipe.

Science.gov (United States)

2010-10-01

... rails, woodcock, and common (Wilson's) snipe. 20.104 Section 20.104 Wildlife and Fisheries UNITED STATES... for rails, woodcock, and common (Wilson's) snipe. This section provides for the annual hunting of certain rails, woodcock, and snipe in the 48 contiguous United States. [44 FR 7148, Feb. 6, 1979...

Interest rates in quantum finance: the Wilson expansion and Hamiltonian.

Science.gov (United States)

Baaquie, Belal E

2009-10-01

Interest rate instruments form a major component of the capital markets. The Libor market model (LMM) is the finance industry standard interest rate model for both Libor and Euribor, which are the most important interest rates. The quantum finance formulation of the Libor market model is given in this paper and leads to a key generalization: all the Libors, for different future times, are imperfectly correlated. A key difference between a forward interest rate model and the LMM lies in the fact that the LMM is calibrated directly from the observed market interest rates. The short distance Wilson expansion [Phys. Rev. 179, 1499 (1969)] of a Gaussian quantum field is shown to provide the generalization of Ito calculus; in particular, the Wilson expansion of the Gaussian quantum field A(t,x) driving the Libors yields a derivation of the Libor drift term that incorporates imperfect correlations of the different Libors. The logarithm of Libor phi(t,x) is defined and provides an efficient and compact representation of the quantum field theory of the Libor market model. The Lagrangian and Feynman path integrals of the Libor market model of interest rates are obtained, as well as a derivation given by its Hamiltonian. The Hamiltonian formulation of the martingale condition provides an exact solution for the nonlinear drift of the Libor market model. The quantum finance formulation of the LMM is shown to reduce to the industry standard Bruce-Gatarek-Musiela-Jamshidian model when the forward interest rates are taken to be exactly correlated.

Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

International Nuclear Information System (INIS)

Cherednikov, Igor O.

2017-01-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Parton densities in quantum chromodynamics. Gauge invariance, path-dependence, and Wilson lines

Energy Technology Data Exchange (ETDEWEB)

Cherednikov, Igor O. [Antwerpen Univ. (Belgium). Dept. Fysica; Veken, Frederik F. van der [CERN, Geneva (Switzerland)

2017-05-01

The purpose of this book is to give a systematic pedagogical exposition of the quantitative analysis of Wilson lines and gauge-invariant correlation functions in quantum chromodynamics. Using techniques from the previous volume (Wilson Lines in Quantum Field Theory, 2014), an ab initio methodology is developed and practical tools for its implementation are presented. Emphasis is put on the implications of gauge invariance and path-dependence properties of transverse-momentum dependent parton density functions. The latter are associated with the QCD factorization approach to semi-inclusive hadronic processes, studied at currently operating and planned experimental facilities.

Metabolism of 25-hydroxyvitamin D in copper-laden rat: A model of Wilson's disease

International Nuclear Information System (INIS)

Carpenter, T.O.; Pendrak, M.L.; Anast, C.S.

1988-01-01

Wilson's disease results in excess tissue accumulation of copper and is often complicated by skeletal and mineral abnormalities. The authors investigated vitamin D metabolism in rats fed a copper-laden diet rendering hepatic copper content comparable with that found in Wilson's disease. Injection of 25-hydroxyvitamin D 3 [25(OH)D 3 ] resulted in reduced 1,25--dihydroxyvitamin D [1,25(OH) 2 D] levels in copper-intoxicated rats. In vitro 25(OH)D-1α-hydroxylase activity was impaired in renal mitochondria from copper-intoxicated animals. Activity was also inhibited in mitochondrial from controls when copper was added to incubation media. Impaired conversion of 25(OH)D to 1,25(OH) 2 D occurs in copper intoxication and suggests that altered vitamin D metabolism is a potential factor in the development of bone and mineral abnormalities in Wilson's disease

BOOK REVIEW: Democracy and Political Life in Nigeria | Wilson ...

African Journals Online (AJOL)

In this review of Victor Dike's book - \\"Democracy and Political Life in Nigeria\\", Inam Wilson underscores the author's attempts to draw a connection between Nigeria's chequered political history and her present economic trajectory to explain why Nigeria is today facing numerous sociopolitical and economic challenges, ...

A prediction for bubbling geometries

OpenAIRE

Okuda, Takuya

2007-01-01

We study the supersymmetric circular Wilson loops in N=4 Yang-Mills theory. Their vacuum expectation values are computed in the parameter region that admits smooth bubbling geometry duals. The results are a prediction for the supergravity action evaluated on the bubbling geometries for Wilson loops.

Wilson's disease in children: clinical and diagnostic features

International Nuclear Information System (INIS)

Ayesha, H.; Choudhry, A.A.; Javed, M.T.; Javed, F.

2002-01-01

Objective: To study the clinical and diagnostic laboratory features of Wilsons disease in children and adolescents. Design: A prospective cohort study. Place and Duration of study: The study included patients diagnosed as Wilson s disease at the Department of Pediatrics Allied Hospital, Punjab medical College, Faisalabad from May 1997 to June 2001. Patients and methods: Patients presenting with liver or suggestive neurological disease were investigated. Others were diagnosed as a result of family screening. Diagnosis of neurologic disease was made if two of the following were present: Typical neurological findings, Kayser Fleischer corneal rings and low serum ceruloplasmin ( 100 mu gm) free serum copper (>10 mu gm/dl). In other forms and for family screening, 24 hours. Urinary copper (> 100 mu gm), free serum copper (>10 mu gm/dl), and wherever possible liver biopsy for histopathology and cytochemical staining by rubeanic acid was also done. Results: Twenty-seven patients with a mean age of 10.2 years were diagnosed as suffering from Wilson disease. Mean age for hepatic and neurological disease was 9 years and 11.5 years respectively. Youngest patient (neurologic) was 6 years old. 48% cases presented with neurological, 41% with hepatic and 4% with skeletal manifestations while 7 % were asymptomatic. Mean duration of symptoms before diagnosis was 6.1 months. Dysarthria (84.6%), tremors (69.2%), rigidity and poor school performance and hand writing (61.5%), dysphagia (46.1%) and dystonia (38.5%), were the most common neurologic findings. Chronic liver disease was seen in 73 % while acute forms were seen in 27 % cases. Two cases presented with fulminant hepatic failure. Consanguineous marriage of the parents was found in 70 % and family history of disease was present in 65 % cases. K-F (Kayser Fleischer) rings and low serum ceruloplasmin(<20 mg/dl) was found in 85% of all patients. In non neurologic types other tests of copper metabolism were done. Elevated urinary

Heavy flavour corrections to polarised and unpolarised deep-inelastic scattering at 3-loop order

International Nuclear Information System (INIS)

Ablinger, J.; Round, M.; Schneider, C.; Hasselhuhn, A.

2016-11-01

We report on progress in the calculation of 3-loop corrections to the deep-inelastic structure functions from massive quarks in the asymptotic region of large momentum transfer Q"2. Recently completed results allow us to obtain the O(a"3_s) contributions to several heavy flavour Wilson coefficients which enter both polarised and unpolarised structure functions for lepton-nucleon scattering. In particular, we obtain the non-singlet contributions to the unpolarised structure functions F_2(x,Q"2) and xF_3(x,Q"2) and the polarised structure function g_1(x,Q"2). From these results we also obtain the heavy flavour contributions to the Gross-Llewellyn-Smith and the Bjorken sum rules.

Wilson and Domainwall Kernels on Oakforest-PACS

Science.gov (United States)

Kanamori, Issaku; Matsufuru, Hideo

2018-03-01

We report the performance of Wilson and Domainwall Kernels on a new Intel Xeon Phi Knights Landing based machine named Oakforest-PACS, which is co-hosted by University of Tokyo and Tsukuba University and is currently fastest in Japan. This machine uses Intel Omni-Path for the internode network. We compare performance with several types of implementation including that makes use of the Grid library. The code is incorporated with the code set Bridge++.

Comments on ''Geomagnetic response to magnetic clouds'' by Robert M. Wilson; and reply

International Nuclear Information System (INIS)

Gonzalez, W.D.; Gonzalez, A.L.C.; Wilson, R.M.

1988-01-01

The paper 'Geomagnetic Response to Magnetic Clouds' by Wilson (1987) tried to show an association between geomagnetic storm intervals and the passage of interplanetary magnetic clouds at the Earth's magnetosphere. The association is shown through a superposed epoch analysis of the interplanetary magnetic field (IMF)-B Z component and the D st geomagnetic storm index for 19 cloud events occurring between 1973 and 1978. Two aspects of the magnetic cloud-storm relationship are challenged. The first concerns the northward-southward rotation of the IMF-B Z component which is known to exist but not accounted for in Wilson's article. The second concerns the magnitude of the storms associated with the passage of magnetic clouds. In a reply Wilson explains the distinction between N-turning and S-turning clouds of the 19 clouds studied 12 were southward and 7 northward turning. The average behaviour of both is similar, the differences being due to the different onset values of D st . The second problem is attributed to a misunderstanding of the meaning of the I-bars given in the original article. The original results of Wilson are reaffirmed. The comment on the reply suggests that the average peak D st value for S-N clouds is larger by 30% than for the N-S clouds and that the final intensity of the storm can be altered by the type of cloud involved (S-N) or (N-S). (U.K.)

New heavy flavor contributions to DIS at the 3-loop order: different masses and nested topologies

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [RISC - JKU Linz (Austria); Bluemlein, Johannes; Wissbrock, Fabian [DESY (Germany)

2013-07-01

We present recent results on the heavy flavor Wilson coefficients of the deep-inelastic structure function F{sub 2} stemming from diagrams which contain both charm- and bottom-quarks. Starting at 3-loop order these contributions cannot be incorporated into the variable flavor number scheme (VFSN). We also present new results on the computation of diagrams of more advanced topologies (knotted ladder, Benz, and others) which have been obtained via the method of hyperlogarithms. They require the use of extensions to the basic formalism leading to the more general class of generalized hyperlogarithms, resp. the associated nested sums. Both the x- and Mellin N-space representations are discussed.

Values in Higher Education. The Wilson Lecture Series.

Science.gov (United States)

Wilson, O. Meredith

The text of a lecture in the University of Arizona Wilson Lecture Series on values in higher education is presented, with responses by Richard H. Gallagher, Jeanne McRae McCarthy, and Raymond H. Thompson. The theme of the talk is that man is by evolution and by necessity a thinking animal, who now finds himself in a technologically dependent…

Wilson's disease: start with psychiatric symptoms. Brain magnetic resonance findings

International Nuclear Information System (INIS)

Nagel, Jorge; Miralles, Sabrina

2007-01-01

Wilson's disease - hepatolenticular degeneration - is an autosomal recessive genetic disorder, characterized by an excessive and toxic accumulation of cooper in different tissues. This accumulation is produced by an inherited defect in cooper's biliary excretion. This rare disorder affects approximately one on 30.000 individuals. Signs and symptoms of hepatic, neurologic and psychiatric disease are the most common clinical presentations of symptomatic Wilson's disease. The diagnosis can usually be made by laboratory tests that find a decreased cooper binding protein in blood called ceruloplasmin, an increase in the excretion of cooper in 24 hour urine and the appearance of corneal Kayser-Fleischer ring. We present a 28 years patient who began with depression and panic attacks, followed by neurologic symptoms. Brain MRI was performed and showed different alterations suggesting the diagnosis of this infrequent sickness. (author) [es

Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

Science.gov (United States)

Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

Ornamental “borderlands”: Elisabeth Wilson and Martin Heydrich’s historiographies of “primitive” ornament

Directory of Open Access Journals (Sweden)

Priyanka Basu

2015-06-01

Full Text Available This article examines texts by Elisabeth Wilson and Martin Heydrich written in 1914 at the University of Leipzig on the subject of ‘primitive’ ornament. Both synopsize the history and literature of this field from its beginnings in the nineteenth century to the time of their writing. This article considers how Wilson and Heydrich represent this history and how the field’s multidisciplinary practitioners perceived its pressing problems. Above all, Wilson and Heydrich set up a number of recurring oppositions between major approaches to ‘primitive’ art and ornament, between ‘materialist’ interpretation, allied with archaeology, symbolic interpretation practiced for the most part by ethnologists, and an ‘aesthetic’ approach, pursued by art theorists and focused on the psychological will of its creators. These issues and this configuration of approaches are further examined in one of August Schmarsow’s important essays on art history and ethnology.

Parasitic copepods on Oligoplites spp. (Osteichthyes, Carangidae from the Brazilian coastal zone, with the redescription of Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae

Directory of Open Access Journals (Sweden)

Ricardo Massato Takemoto

2002-05-01

Full Text Available Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 and O. saliens (Bloch, 1793 (Osteichthyes: Carangidae from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908 are given. Caligus oligoplitisi Carvalho, 1954 is considered a new junior synonym of C. robustus. Fishes of the genus Oligoplites are new host records for this species of copepod. Redescription and illustration of Tuxophorus caligodes Wilson, 1908, collected on the body surface of Oligoplites saliens, O. palometa and O. saurus, are provided.Quatro espécies de copépodes caligídeos, parasitos de Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 e O. saliens (Bloch, 1793 (Osteichthyes, Carangidae da Baia de Sepetiba, litoral do Estado do Rio de Janeiro, Brasil, são descritos. São apresentados o registro de novo hospedeiro e nova distribuição geográfica para Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 e Metacaligus rufus (Wilson, 1908. Caligus oligoplitisi Carvalho, 1954, é considerado novo sinônimo júnior de C. robustus. Tuxophorus caligodes Wilson, 1908, coletado na superfície do corpo de Oligoplites saliens, O. palometa e O. saurus é redescrito e ilustrado. Peixes do gênero Oligoplites são novos hospedeiros para estas espécies de copépodes.

A history of altruism focusing on Darwin, Allee and E.O. Wilson.

Science.gov (United States)

Domondon, Andrew T

2013-06-01

The problem of altruism refers to the apparent difficulty in reconciling the existence of altruists, individuals who reduce their own fitness to increase the fitness of others, with natural selection. A historical and philosophical overview of solutions to this apparent contradiction is presented through a close reading of the key texts of Charles Darwin, Warder C. Allee and Edward O. Wilson. Following an analysis of Darwin's explanation for altruism, I examine the ideas of group selection and kin selection advanced by Allee and Wilson, respectively, Attention is also given to the philosophical implications each associated with their respective solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tuning up an oldtimer: hybrid Monte Carlo with Wilson fermions

International Nuclear Information System (INIS)

Schilling, K.; Hannemann, V.; Lippert, T.; Noeckel, B.

1995-01-01

We show that BiCGStab inversion algorithm helps to speed up by 50% the computation of the fermionic force inside the Hybrid Monte Carlo (HMC) simulation of full QCD with Wilson fermions, in the chiral regime of small quark masses. ((orig.))

X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

International Nuclear Information System (INIS)

Kumar, Pankaj; Cho, Kyung-Suk; Nakariakov, Valery M.

2015-01-01

We report decaying quasi-periodic intensity oscillations in the X-ray (6–12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in the X-ray channel (6–12 keV) were about 202 and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 Å channels. Simultaneously, AIA hot channels (94 and 131 Å) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km s −1 for about 115 Mm of loop length, which is roughly consistent with the sound speed at the temperature about 10–16 MK (480–608 km s −1 ). These EUV oscillations are consistent with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could have caused the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and that are precipitating there, causing the observed 202 s periodicity. Other possible interpretations, e.g., the second harmonics of the slow mode, are also discussed

X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pankaj; Cho, Kyung-Suk [Korea Astronomy and Space Science Institute (KASI), Daejeon, 305-348 (Korea, Republic of); Nakariakov, Valery M., E-mail: pankaj@kasi.re.kr [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL (United Kingdom)

2015-05-01

We report decaying quasi-periodic intensity oscillations in the X-ray (6–12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in the X-ray channel (6–12 keV) were about 202 and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 Å channels. Simultaneously, AIA hot channels (94 and 131 Å) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km s{sup −1} for about 115 Mm of loop length, which is roughly consistent with the sound speed at the temperature about 10–16 MK (480–608 km s{sup −1}). These EUV oscillations are consistent with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could have caused the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and that are precipitating there, causing the observed 202 s periodicity. Other possible interpretations, e.g., the second harmonics of the slow mode, are also discussed.

Clinical investigation in Wilson's disease

International Nuclear Information System (INIS)

Mizutani, Naoki; Maehara, Mitsuo; Negoro, Tamiko; Watanabe, Kazuyoshi

1983-01-01

Wilson's disease of cerebral type with a chief complaint of tremor occurred in 3 brothers and sisters of a certain family line. Treatment with D-penicillamine produced remarkable clinical improvement as shown by the disappearance of tremor and Kayser-Fleischer ring. Cranial CT scans made before the treatment revealed abnormal findings such as low density areas in the (bilateral) thalamus and the lenticular nucleus, atrophy of the cerebral cortex, and enlargement of the ventricles. After the treatment, cranial CT revealed that the low density areas in the thalamus and the lenticular nucleus disappeared corresponding to the clinical improvement. However, the atrophy of the cerebral cortex and the enlargement of the ventricles were not ameliorated. (Ueda, J.)

The 3-loop non-singlet heavy flavor contributions to the structure function g1(x,Q2 at large momentum transfer

Directory of Open Access Journals (Sweden)

A. Behring

2015-08-01

Full Text Available We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the polarized structure function g1(x,Q2 in the asymptotic region Q2≫m2 to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N and the momentum fraction x, and derive heavy flavor corrections to the Bjorken sum-rule. Numerical results are presented for the charm quark contribution. Results on the structure function g2(x,Q2 in the twist-2 approximation are also given.

ESO Telescope Designer Raymond Wilson Wins Prestigious Kavli Award for Astrophysics

Science.gov (United States)

2010-06-01

Raymond Wilson, whose pioneering optics research at ESO made today's giant telescopes possible thanks to "active optics" technology, has been awarded the 2010 Kavli Prize in astrophysics. The founder and original leader of the Optics and Telescopes Group at ESO, Wilson shares the million-dollar prize with two American scientists, Jerry Nelson and Roger Angel. The biennial prize, presented by the Norwegian Academy of Science and Letters, the Kavli Foundation, and the Norwegian Ministry of Education and Research, was instituted in 2008 and is given to researchers who significantly advance knowledge in the fields of nanoscience, neuroscience, and astrophysics, acting as a complement to the Nobel Prize. The award is named for and funded by Fred Kavli, the Norwegian entrepreneur and phi­lanthropist who later founded the Kavlico Corpora­tion in the US - today one of the world's largest suppliers of sensors for aeronautic, automotive and industrial applications. Wilson, who joined ESO in 1972, strived to achieve optical perfection, developing the concept of active optics as a way to enhance the size of telescopic primary mirrors. It is the size of these mirrors that determines the ability of a telescope to gather light and study faint and distant objects. Before active optics, mirrors over six metres in diameter were impossible, being too heavy, costly, and likely to bend from gravity and temperature changes. The use of active optics, which preserves optimal image quality by continually adjusting the mirror's shape during observations, made lighter, thinner so-called "meniscus mirrors" possible. Wilson first led the implementation of active optics in the revolutionary New Technology Telescope at ESO's La Silla Observatory, and continued to develop and improve the technology until his retirement in 1993. Since then, active optics have become a standard part of modern astronomy, applied in every big telescope including ESO's Very Large Telescope (VLT), a telescope array

The influence of wall materials on Cs depositions in HTR coolant loops

International Nuclear Information System (INIS)

Herion, J.

1975-01-01

The basic concepts on the effect of the wall material on the deposition of fission products in high temperature reactor (HTR) coolant loops are developed which include the mechanisms of adsorption, solubility and diffusion. General mathematical interrelations of the Cs-adsorption on technical metals are presented and discussed using experimental data from the literature. Desorption energies and frequency factors are determined from measurements of the electrons' work function of metals in Cs atmosphere from R.G. Wilson using these mathematical interrelations. The solubilities and the diffusion constants of Cs are so small in the few investigated cases (Mo, Ta) that high diffusivity paths must be taken into account. Thermochemical considerations on the influence of gaseous impurities on the deposition behaviour are lacking in reliable data. (orig./LH) [de

Multivariable biorthogonal continuous--discrete Wilson and Racah polynomials

International Nuclear Information System (INIS)

Tratnik, M.V.

1990-01-01

Several families of multivariable, biorthogonal, partly continuous and partly discrete, Wilson polynomials are presented. These yield limit cases that are purely continuous in some of the variables and purely discrete in the others, or purely discrete in all the variables. The latter are referred to as the multivariable biorthogonal Racah polynomials. Interesting further limit cases include the multivariable biorthogonal Hahn and dual Hahn polynomials

Détermination expérimentale des paramètres de Wilson Experimental Dertermination of Wilson Parameters

Directory of Open Access Journals (Sweden)

Monfort J.-P.

2006-11-01

Full Text Available La volabilité relative ait; =(yilxil(Y;lxi des constituants d'un mélange binaire a été mesurée à partir d'un nouveau dispositif expérimental, on reporte les données d'équilibre liquide-vapeur obtenues à 45'C de plusieurs binaires : toluène-acétoni-trile, benzène-acétonitrile et benzène-n-heptane. En ajustant à l'équation de Wilson les données expérimentales de «i/; de ces constituants ainsi que des volatilités relatives des constituants des mélanges d'hydrocarbures-alcools, obtenues dans un précédent travail, on calcule les paramètres énergétiques. La prédiction des points de bulle de mélanges binaires et ternaires obtenue à partir de ces paramètres est satisfaisante. La méthode expérimentale ainsi proposée convient particulièrement pour la sélection des solvant extractifs utilisés dans la distillation extractive. From a new expérimental method, relative volatilities aiti = (yilxil(yilxi for a binary mixture are obtained; vapor-liquid equilibrium data are presented for several systems, i.e. toluene-acétonitrile, benzene-acétonitrile and benzene-n-heptane at 45°C. The two adjustable energyparameters of thé Wilson équation, are obtained by adopting thé «,/j data for these binary mixtures and for alcohol-hydrocarbon mixtures previously studied. Theresults obtained in predicting bubble-pressure data for binary and ternary mixtures are consistent with experimental data.

THE CORONAL LOOP INVENTORY PROJECT: EXPANDED ANALYSIS AND RESULTS

Energy Technology Data Exchange (ETDEWEB)

Schmelz, J. T. [USRA, 7178 Columbia Gateway Drive, Columbia, MD 21046 (United States); Christian, G. M.; Chastain, R. A., E-mail: jschmelz@usra.edu [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

2016-11-10

We have expanded upon earlier work that investigates the relative importance of coronal loops with isothermal versus multithermal cross-field temperature distributions. These results are important for determining if loops have substructure in the form of unresolved magnetic strands. We have increased the number of loops targeted for temperature analysis from 19 to 207 with the addition of 188 new loops from multiple regions. We selected all loop segments visible in the 171 Å images of the Atmospheric Imaging Assembly (AIA) that had a clean background. Eighty-six of the new loops were rejected because they could not be reliably separated from the background in other AIA filters. Sixty-one loops required multithermal models to reproduce the observations. Twenty-eight loops were effectively isothermal, that is, the plasma emission to which AIA is sensitive could not be distinguished from isothermal emission, within uncertainties. Ten loops were isothermal. Also, part of our inventory was one small flaring loop, one very cool loop whose temperature distribution could not be constrained by the AIA data, and one loop with inconclusive results. Our survey can confirm an unexpected result from the pilot study: we found no isothermal loop segments where we could properly use the 171-to-193 ratio method, which would be similar to the analysis done for many loops observed with TRACE and EIT. We recommend caution to observers who assume the loop plasma is isothermal, and hope that these results will influence the direction of coronal heating models and the effort modelers spend on various heating scenarios.

One-loop masses of open-string scalar fields in string theory

International Nuclear Information System (INIS)

Kitazawa, Noriaki

2008-01-01

In phenomenological models with D-branes, there are in general open-string massless scalar fields, in addition to closed-string massless moduli fields corresponding to the compactification. It is interesting to focus on the fate of such scalar fields in models with broken supersymmetry, because no symmetry forbids their masses. The one-loop effect may give non-zero masses to them, and in some cases mass squared may become negative, which means the radiative gauge symmetry breaking. In this article we investigate and propose a simple method for calculating the one-loop corrections using the boundary state formalism. There are two categories of massless open-string scalar fields. One consists the gauge potential fields corresponding to compactified directions, which can be understood as scalar fields in uncompactified space-time (related with Wilson line degrees of freedom). The other consists 'gauge potential fields' corresponding to transverse directions of D-brane, which emerge as scalar fields in D-brane world-volume (related with brane moduli fields). The D-brane boundary states with constant backgrounds of these scalar fields are constructed, and one-loop scalar masses are calculated in the closed string picture. Explicit calculations are given in the following four concrete models: one D25-brane with a circle compactification in bosonic string theory, one D9-brane with a circle compactification in superstring theory, D3-branes at a supersymmetric C 3 /Z 3 orbifold singularity, and a model of brane supersymmetry breaking with D3-branes and anti-D7-branes at a supersymmetric C 3 /Z 3 orbifold singularity. We show that the sign of the mass squared has a strong correlation with the sign of the related open-string one-loop vacuum amplitude.

Quantum Gowdy model within the new loop quantum cosmology improved dynamics

International Nuclear Information System (INIS)

Martin-Benito, M; Garay, L J; Mena Marugan, G A

2011-01-01

The linearly polarized Gowdy T 3 model can be regarded as compact Bianchi I cosmologies with inhomogeneous modes allowed to travel in one direction. We study a hybrid quantization of this model that combines the loop quantization of the Bianchi I background, adopting the improved dynamics scheme put forward by Ashtekar and Wilson-Ewing, with a Fock quantization for the inhomogeneities. The Hamiltonian constraint operator provides a resolution of the cosmological singularity and superselects separable sectors. We analyze the complicated structure of these sectors. In any of them the Hamiltonian constraint provides an evolution equation with respect to the volume of the associated Bianchi I universe, with a well posed initial value problem. This fact allows us to construct the Hilbert space of physical states and to show that we recover the standard quantum field theory for the inhomogeneities.

Nucleon electromagnetic form factors with Wilson fermions

International Nuclear Information System (INIS)

Goeckeler, M.; Haegler, P.; Horsley, R.

2007-10-01

The nucleon electromagnetic form factors continue to be of major interest for experimentalists and phenomenologists alike. They provide important insights into the structure of nuclear matter. For a range of interesting momenta they can be calculated on the lattice. The limiting factor continues to be the value of the pion mass. We present the latest results of the QCDSF collaboration using gauge configurations with two dynamical, non-perturbatively improved Wilson fermions at pion masses as low as 350 MeV. (orig.)

Nucleon electromagnetic form factors with Wilson fermions

Energy Technology Data Exchange (ETDEWEB)

Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Technische Univ. Muenchen, Garching (Germany). Inst. fuer Theoretische Physik; Horsley, R. [Edinburgh Univ. (GB). School of Physics] (and others)

2007-10-15

The nucleon electromagnetic form factors continue to be of major interest for experimentalists and phenomenologists alike. They provide important insights into the structure of nuclear matter. For a range of interesting momenta they can be calculated on the lattice. The limiting factor continues to be the value of the pion mass. We present the latest results of the QCDSF collaboration using gauge configurations with two dynamical, non-perturbatively improved Wilson fermions at pion masses as low as 350 MeV. (orig.)

Chromosomenindividualität or Entmischung? The debate between Paolo Della Valle and Edmund B. Wilson.

Science.gov (United States)

Volpone, Alessandro

2015-01-01

At the beginning of the twentieth century, the Italian cytologist Paolo Della Valle developed a theory of instable chromosomes (teoria dei cromosomi labili). He radically criticized the so-called Sutton-Boveri hypothesis (Martins and Martins, Genetics and Molecular Biology, 22:261-271, 1999), focusing on numerical constancy in the species and individuality. On the basis of bibliographical review and personal observations, he maintained that the chromosomes were neither stable bodies, nor permanent structures, but transitory cellular materials, resulting from the periodical rearrangement of the chromatin during the cell division. German and English-speaking biologists reacted. The paper shows some content of the argumentations used by Thomas H. Montgomery and especially Edmund B. Wilson. The discussion was characterized by the same data which is interpretedby different scholars in different ways. And the point is that no one of them had the decisive test to demonstrate his own point of view. Wilson simply invoked on his behalf a certain 'common sense', defending at least a 'high degree of constancy'. The debate waned along with the reception of Morgan's chromosome theory of heredity, but only the advent of molecular biology definitively stated the nature of chromosomes as permanent structures of the cell.

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.

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

Two-phase Heating in Flaring Loops

Science.gov (United States)

Zhu, Chunming; Qiu, Jiong; Longcope, Dana W.

2018-03-01

We analyze and model a C5.7 two-ribbon solar flare observed by the Solar Dynamics Observatory, Hinode, and GOES on 2011 December 26. The flare is made of many loops formed and heated successively over one and half hours, and their footpoints are brightened in the UV 1600 Å before enhanced soft X-ray and EUV missions are observed in flare loops. Assuming that anchored at each brightened UV pixel is a half flaring loop, we identify more than 6700 half flaring loops, and infer the heating rate of each loop from the UV light curve at the footpoint. In each half loop, the heating rate consists of two phases: intense impulsive heating followed by a low-rate heating that is persistent for more than 20 minutes. Using these heating rates, we simulate the evolution of their coronal temperatures and densities with the model of the “enthalpy-based thermal evolution of loops.” In the model, suppression of thermal conduction is also considered. This model successfully reproduces total soft X-ray and EUV light curves observed in 15 passbands by four instruments GOES, AIA, XRT, and EVE. In this flare, a total energy of 4.9 × 1030 erg is required to heat the corona, around 40% of this energy is in the slow-heating phase. About two-fifths of the total energy used to heat the corona is radiated by the coronal plasmas, and the other three fifth transported to the lower atmosphere by thermal conduction.

Loop corrections to primordial non-Gaussianity

Science.gov (United States)

Boran, Sibel; Kahya, E. O.

2018-02-01

We discuss quantum gravitational loop effects to observable quantities such as curvature power spectrum and primordial non-Gaussianity of cosmic microwave background (CMB) radiation. We first review the previously shown case where one gets a time dependence for zeta-zeta correlator due to loop corrections. Then we investigate the effect of loop corrections to primordial non-Gaussianity of CMB. We conclude that, even with a single scalar inflaton, one might get a huge value for non-Gaussianity which would exceed the observed value by at least 30 orders of magnitude. Finally we discuss the consequences of this result for scalar driven inflationary models.

Wilson line distributions in hot SU(2) gluodynamics

International Nuclear Information System (INIS)

Ilgenfritz, E.M.

1982-01-01

Monte-Carlo results concerning the order parameter related to confinement and its distribution from the point of view of the dilute instanton gas approximation are Discussed. Identified is a threshold effect in the Wilson line distribution with the onset of instantons and established is the relation between the temperature of instanton saturation and the confinement temperature. Some other details of our Monte-Carlo results are reported as well

Raising and Lowering Operators for Askey-Wilson Polynomials

Directory of Open Access Journals (Sweden)

Siddhartha Sahi

2007-01-01

Full Text Available In this paper we describe two pairs of raising/lowering operators for Askey-Wilson polynomials, which result from constructions involving very different techniques. The first technique is quite elementary, and depends only on the ''classical'' properties of these polynomials, viz. the q-difference equation and the three term recurrence. The second technique is less elementary, and involves the one-variable version of the double affine Hecke algebra.

The running coupling from the QCD Schrödinger functional a one-loop analysis

CERN Document Server

Sint, S; Sint, Stefan; Sommer, Rainer

1996-01-01

Starting from the Schr\\"odinger functional, we give a non-perturbative definition of the running coupling constant in QCD. The spatial boundary conditions for the quark fields are chosen such that the massless Dirac operator in the classical background field has a large smallest eigenvalue. At one-loop order of perturbation theory, we determine the matching coefficient to the \\MSbar-scheme and discuss the quark mass effects in the \\beta-function. To this order, we also compute the Symanzik improvement coefficient necessary to remove the \\Oa lattice artefacts originating from the boundaries. For reasonable lattice resolutions and the standard Wilson action, lattice artefacts are found to be only weakly dependent on the lattice spacing a, while they vanish quickly with the improved action of Sheikholeslami and Wohlert.

The contribution of scalars to N=4 SYM amplitudes II: Young tableaux, asymptotic factorisation and strong coupling

Directory of Open Access Journals (Sweden)

Alfredo Bonini

2018-06-01

Full Text Available We disentangle the contribution of scalars to the OPE series of null hexagonal Wilson loops/MHV gluon scattering amplitudes in multicolour N=4 SYM. In specific, we develop a systematic computation of the SU(4 matrix part of the Wilson loop by means of Young tableaux (with several examples. Then, we use a peculiar factorisation property (when a group of rapidities becomes large to deduce an explicit polar form. Furthermore, we emphasise the advantages of expanding the logarithm of the Wilson loop in terms of ‘connected functions’ as we apply this procedure to find an explicit strong coupling expansion (definitively proving that the leading order can prevail on the classical AdS5 string contribution.

LoopIng: a template-based tool for predicting the structure of protein loops.

KAUST Repository

Messih, Mario Abdel

2015-08-06

Predicting the structure of protein loops is very challenging, mainly because they are not necessarily subject to strong evolutionary pressure. This implies that, unlike the rest of the protein, standard homology modeling techniques are not very effective in modeling their structure. However, loops are often involved in protein function, hence inferring their structure is important for predicting protein structure as well as function.We describe a method, LoopIng, based on the Random Forest automated learning technique, which, given a target loop, selects a structural template for it from a database of loop candidates. Compared to the most recently available methods, LoopIng is able to achieve similar accuracy for short loops (4-10 residues) and significant enhancements for long loops (11-20 residues). The quality of the predictions is robust to errors that unavoidably affect the stem regions when these are modeled. The method returns a confidence score for the predicted template loops and has the advantage of being very fast (on average: 1 min/loop).www.biocomputing.it/loopinganna.tramontano@uniroma1.itSupplementary data are available at Bioinformatics online.

Eugene Onegin the Cold War Monument: How Edmund Wilson Quarreled with Vladimir Nabokov

Directory of Open Access Journals (Sweden)

Tim Conley

2014-01-01

Full Text Available The tale of how Edmund Wilson quarreled with Vladimir Nabokov over the latter’s 1964 translation of Eugene Onegin can be instructively read as a politically charged event, specifically a “high culture” allegory of the Cold War. Dissemination of anti-Communist ideals (often in liberal and literary guises was the mandate of the Congress for Cultural Freedom, whose funding and editorial initiatives included the publication of both pre-Revolution Russian literature and, more notoriously, the journal Encounter (1953-1990, where Nabokov’s fiery “Reply” to Wilson appeared. This essay outlines the propaganda value of the Onegin debate within and to Cold War mythology.

The Samba Controversy between Noel Rosa and Wilson Batista: Intertextuality and the Meanders of Composition

Directory of Open Access Journals (Sweden)

Leandro Moreira da Luz

2015-07-01

Full Text Available The purpose of this paper is to analyze the meanders of composition and their intertextuality in the samba controversy between Noel Rosa and Wilson Batista. We observe dialogism in the verbal and musical interaction between the samba writers and several texts of the 1930s. When ears are in tune with the "samba controversy," one observes that the compositions reveal inexorable tensions between the festive world of the "malandro" and the limits of the reality of the time. Accordingly, based on studies that address this theme, we aim to present an insight into this musical "duel," which is not restricted to purely aesthetics issues, but certainly disseminated in society.

Clinical presentation and mutations in Danish patients with Wilson disease

DEFF Research Database (Denmark)

Møller, Lisbeth Birk; Horn, Nina; Jeppesen, Tina Dysgaard

2011-01-01

This study describes the clinical presentation and diagnosis in all Danish patients (49, 41 unrelated) with Wilson disease (WND). On the basis of the number of diagnosed patients from 1990-2008, the prevalence was estimated to be 1:49¿500. Among routinely used diagnostic tests, none were...

Clinical presentation and mutations in Danish patients with Wilson disease

DEFF Research Database (Denmark)

Møller, Lisbeth Birk; Horn, Nina; Jeppesen, Tina Dysgaard

2011-01-01

This study describes the clinical presentation and diagnosis in all Danish patients (49, 41 unrelated) with Wilson disease (WND). On the basis of the number of diagnosed patients from 1990-2008, the prevalence was estimated to be 1:49 500. Among routinely used diagnostic tests, none were...

How Hugh Hampton Young's treatment of President Woodrow Wilson's urinary retention and urosepsis affected the resolution of World War I.

Science.gov (United States)

Fogg, Ryan; Kutikov, Alexander; Uzzo, Robert G; Canter, Daniel

2011-09-01

President Woodrow Wilson was never able to gain ratification of the Treaty of Versailles, the peace accord to end World War I. Before he could convince the American people of the importance of ratification, Wilson suffered a stroke followed by life threatening urinary sepsis due to urinary retention, and was treated by the father of modern urology, Hugh Hampton Young. The effects of these health problems are examined in the context of their implications on international affairs. Biographical sources and primary documentation of Wilson's physicians were reviewed to determine the effect of Wilson's stroke on his voiding habits. Hugh Hampton Young's evaluation and decision making is examined in depth. In the fall of 1919 President Wilson was recovering from a stroke. Shortly after the stroke his preexisting voiding dysfunction progressed to urinary retention from which urinary sepsis developed. Hugh Hampton Young advised on Wilson's case and counseled patience over surgery. The President began voiding spontaneously and recovered from sepsis. The illness left him severely weakened and unable to mount an aggressive campaign to persuade the U.S. Senate of the importance of ratifying the Treaty of Versailles. His personal physician, Admiral Cary T. Grayson, stated that the President was mentally never the same after the sepsis. Wilson's voiding dysfunction contributed to his inability to win approval for the Treaty of Versailles and the League of Nations. As a result, the United States returned to a policy of isolationism and Europe plunged into 2 decades of upheaval, leading to World War II. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Mass transfer of steels for FBR in sodium loop

International Nuclear Information System (INIS)

Susukida, Hiroshi; Yonezawa, Toshio; Ueda, Mitsuo; Imazu, Takayuki; Kiyokawa, Teruyuki.

1976-06-01

In order to grasp quantitatively the corrosion and mass transfer of steels for FBR in sodium loop and to establish their allowable stress value and corrosion rate, a special sodium loop for material testing was designed and fabricated and the steels were given 3010 hours exposing test in the sodium loop. This paper gives the outline of the sodium loop and the results of the test. (1) Carburization and a slight increase in weight were observed in the specimens of type 304 stainless steel exposed in the sodium loop for 3010 hours, while decarburization was observed in the specimens of 2 1/4 Cr-1 Mo steel. It is considered that these phenomena were caused by the downstream factor of the sodium loop. (2) A remarkable decrease of Charpy absorbed energy was observed in the specimens of type 304 stainless steel exposed in the sodium loop. It is considered that this resulted from the weakening of the grain boundary due to heat history and mass transfer. (3) The specimens exposed in the sodium loop must be washed by ultrasonic waves in a water bath after washing in alcohol. (auth.)

Pontes e rupturas no fabular de Wilson Bueno

OpenAIRE

Furquim, Fulvia Maria Giaretta de Almeida

2008-01-01

O trabalho tem por objetivo analisar tres obras contemporaneas do escritor paranaense Wilson Bueno (1949- ), que fazem parte de um projeto literario, em que as personagens sao apresentadas de uma visao inicialmente plural, como se apenas uma delas pudesse ser a representacao do todo, para uma optica individualista, caracteristica de um sistema capitalista. Sao elas: Manual de Zoofilia (1991), Jardim Zoologico (1999) e Cachorrros do Ceu (2005). O escritor contemporaneo segue a tradicao dos bes...

Wilson flow and scale setting from lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Bornyakov, V.G. [Institute for High Energy Physics, Protvino (Russian Federation); Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation). School of Biomedicine; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Hudspith, R. [York Univ., Toronto, ON (Canada). Dept. of Mathematics and Statistics; Collaboration: QCDSF-UKQCD Collaboration; and others

2015-08-15

We give a determination of the phenomenological value of the Wilson (or gradient) flow scales t{sub 0} and w{sub 0} for 2+1 flavours of dynamical quarks. The simulations are performed keeping the average quark mass constant, which allows the approach to the physical point to be made in a controlled manner. O(a) improved clover fermions are used and together with four lattice spacings this allows the continuum extrapolation to be taken.

Quark contribution to the small-x evolution of color dipole

Energy Technology Data Exchange (ETDEWEB)

Ian Balitsky

2006-09-11

The small-x deep inelastic scattering in the saturation region is governed by the non-linear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the BK equation for the evolution of color dipoles. In the NLO the nonlinear equation gets contributions from quark and gluon loops. In this paper I calculate the quark-loop contribution to small-x evolution of Wilson lines in the NLO. It turns out that there are no new operators at the one-loop level--just as at the tree level, the high-energy scattering can be described in terms of Wilson lines. In addition, from the analysis of quark loops I find that the argument of coupling constant in the BK equation is determined by the size of the parent dipole rather than by the size of produced dipoles. These results are to be supported by future calculation of gluon loops.

Mowat-Wilson syndrome

Science.gov (United States)

Garavelli, Livia; Mainardi, Paola Cerruti

2007-01-01

Mowat-Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by a distinct facial phenotype (high forehead, frontal bossing, large eyebrows, medially flaring and sparse in the middle part, hypertelorism, deep set but large eyes, large and uplifted ear lobes, with a central depression, saddle nose with prominent rounded nasal tip, prominent columella, open mouth, with M-shaped upper lip, frequent smiling, and a prominent but narrow and triangular pointed chin), moderate-to-severe intellectual deficiency, epilepsy and variable congenital malformations including Hirschsprung disease (HSCR), genitourinary anomalies (in particular hypospadias in males), congenital heart defects, agenesis of the corpus callosum and eye anomalies. The prevalence of MWS is currently unknown, but 171 patients have been reported so far. It seems probable that MWS is under-diagnosed, particularly in patients without HSCR. MWS is caused by heterozygous mutations or deletions in the Zinc finger E-box-binding homeobox 2 gene, ZEB2, previously called ZFHX1B (SIP1). To date, over 100 deletions/mutations have been reported in patients with a typical phenotype; they are frequently whole gene deletions or truncating mutations, suggesting that haploinsufficiency is the main pathological mechanism. Studies of genotype-phenotype analysis show that facial gestalt and delayed psychomotor development are constant clinical features, while the frequent and severe congenital malformations are variable. In a small number of patients, unusual mutations can lead to an atypical phenotype. The facial phenotype is particularly important for the initial clinical diagnosis and provides the hallmark warranting ZEB2 mutational analysis, even in the absence of HSCR. The majority of MWS cases reported so far were sporadic, therefore the recurrence risk is low. Nevertheless, rare cases of sibling recurrence have been observed. Congenital malformations and seizures require precocious clinical

Mowat-Wilson syndrome

Directory of Open Access Journals (Sweden)

Mainardi Paola

2007-10-01

Full Text Available Abstract Mowat-Wilson syndrome (MWS is a multiple congenital anomaly syndrome characterized by a distinct facial phenotype (high forehead, frontal bossing, large eyebrows, medially flaring and sparse in the middle part, hypertelorism, deep set but large eyes, large and uplifted ear lobes, with a central depression, saddle nose with prominent rounded nasal tip, prominent columella, open mouth, with M-shaped upper lip, frequent smiling, and a prominent but narrow and triangular pointed chin, moderate-to-severe intellectual deficiency, epilepsy and variable congenital malformations including Hirschsprung disease (HSCR, genitourinary anomalies (in particular hypospadias in males, congenital heart defects, agenesis of the corpus callosum and eye anomalies. The prevalence of MWS is currently unknown, but 171 patients have been reported so far. It seems probable that MWS is under-diagnosed, particularly in patients without HSCR. MWS is caused by heterozygous mutations or deletions in the Zinc finger E-box-binding homeobox 2 gene, ZEB2, previously called ZFHX1B (SIP1. To date, over 100 deletions/mutations have been reported in patients with a typical phenotype; they are frequently whole gene deletions or truncating mutations, suggesting that haploinsufficiency is the main pathological mechanism. Studies of genotype-phenotype analysis show that facial gestalt and delayed psychomotor development are constant clinical features, while the frequent and severe congenital malformations are variable. In a small number of patients, unusual mutations can lead to an atypical phenotype. The facial phenotype is particularly important for the initial clinical diagnosis and provides the hallmark warranting ZEB2 mutational analysis, even in the absence of HSCR. The majority of MWS cases reported so far were sporadic, therefore the recurrence risk is low. Nevertheless, rare cases of sibling recurrence have been observed. Congenital malformations and seizures require

[Wilson's principles--a base of modern teratology].

Science.gov (United States)

Burdan, Franciszek; Bełzek, Artur; Szumiło, Justyna; Dudka, Jarosław; Korobowicz, Agnieszka; Tokarska, Edyta; Klepacz, Lidia; Bełzek, Marta; Klepacz, Robert

2006-03-01

Wilson's principles were formulated after thalidomide tragedy. They become a fundamental for teratological studies with drugs and other factors that may disturb fetal development. It is postulated that susceptibility to teratogen depends on the genotype and developmental stage of the conceptus. Teratogenic agents act in specific manner on developing cells and tissues. The exposition depends on the agent's nature and availability. Manifestations of deviant development depends on the dosage and exposure frequency. In case of abnormal development the final manifestations include death of embryo or fetus, malformation, growth retardation and functional disorder.

Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

Science.gov (United States)

Zhao, Bo; Li, Yuanchun

2015-01-01

This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

Directory of Open Access Journals (Sweden)

Bo Zhao

Full Text Available This paper considers a decentralized fault tolerant control (DFTC scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO. Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

Off-shell amplitudes as boundary integrals of analytically continued Wilson line slope

International Nuclear Information System (INIS)

Kotko, P.; Serino, M.; Staśto, A.M.

2016-01-01

One of the methods to calculate tree-level multi-gluon scattering amplitudes is to use the Berends-Giele recursion relation involving off-shell currents or off-shell amplitudes, if working in the light cone gauge. As shown in recent works using the light-front perturbation theory, solutions to these recursions naturally collapse into gauge invariant and gauge-dependent components, at least for some helicity configurations. In this work, we show that such structure is helicity independent and emerges from analytic properties of matrix elements of Wilson line operators, where the slope of the straight gauge path is shifted in a certain complex direction. This is similar to the procedure leading to the Britto-Cachazo-Feng-Witten (BCFW) recursion, however we apply a complex shift to the Wilson line slope instead of the external momenta. While in the original BCFW procedure the boundary integrals over the complex shift vanish for certain deformations, here they are non-zero and are equal to the off-shell amplitudes. The main result can thus be summarized as follows: we derive a decomposition of a helicity-fixed off-shell current into gauge invariant component given by a matrix element of a straight Wilson line plus a reminder given by a sum of products of gauge invariant and gauge dependent quantities. We give several examples realizing this relation, including the five-point next-to-MHV helicity configuration.

Fermionic pentagons and NMHV hexagon

Directory of Open Access Journals (Sweden)

A.V. Belitsky

2015-05-01

Full Text Available We analyze the near-collinear limit of the null polygonal hexagon super Wilson loop in the planar N=4 super-Yang–Mills theory. We focus on its Grassmann components which are dual to next-to-maximal helicity-violating (NMHV scattering amplitudes. The kinematics in question is studied within a framework of the operator product expansion that encodes propagation of excitations on the background of the color flux tube stretched between the sides of Wilson loop contour. While their dispersion relation is known to all orders in 't Hooft coupling from previous studies, we find their form factor couplings to the Wilson loop. This is done making use of a particular tessellation of the loop where pentagon transitions play a fundamental role. Being interested in NMHV amplitudes, the corresponding building blocks carry a nontrivial charge under the SU(4 R-symmetry group. Restricting the current consideration to twist-two accuracy, we analyze two-particle contributions with a fermion as one of the constituents in the pair. We demonstrate that these nonsinglet pentagons obey bootstrap equations that possess consistent solutions for any value of the coupling constant. To confirm the correctness of these predictions, we calculate their contribution to the super Wilson loop demonstrating agreement with recent results to four-loop order in 't Hooft coupling.

Persistently and asymptomatic raised liver enzymes as a form of presentation of Wilson's disease at pediatric age

Directory of Open Access Journals (Sweden)

Catarina Matos

2015-06-01

Full Text Available Background: Wilson`s disease is a rare autosomal recessive disorder characterized by a change in the transport of copper in the liver, with progressive accumulation in this and other organs such as brain, kidney and cornea. Phenotypic expression of the disease varies widely and can range from elevated liver enzymes, fatty liver or gallstones in asymptomatic patients, to cirrhosis and fulminant hepatic failure, or disabling neuropsychiatric disease. Aim: To characterize a sample of patients with Wilson´s disease. Patients and Methods: Retrospective survey including children diagnosed with Wilson´s disease between 2002 and 2011 according to the criteria of the European Association for the Study of the Liver (2012. We analyzed family history; age, clinical data, imaging and histology at the time of diagnosis; genetic analysis; treatment and side effects; follow-up and current status. Results: We identified five patients. Three had a family history of disease. All were asymptomatic and had maintained raised liver enzymes. No patient had clinical stigmata of chronic liver disease. One female patient had overweight. All were treated with D-penicillamine, withdrawn in two patients because of side effects. Currently all patients remain asymptomatic, without evidence of progression of liver disease, with a median follow-up of 5 years and 3 months. Discussion: Our series show that Wilson´s disease may be present with raised liver enzymes in asymptomatic children. The overweight patient alerts us to screen the disease in overweight/obese patients with raised liver enzymes and/or steatosis persisting for more than six months after weight loss.

Kalman Orbit Optimized Loop Tracking

Science.gov (United States)

Young, Lawrence E.; Meehan, Thomas K.

2011-01-01

Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

Dualities in ABJM matrix model from closed string viewpoint

Energy Technology Data Exchange (ETDEWEB)

Kiyoshige, Kazuki; Moriyama, Sanefumi [Department of Physics, Graduate School of Science, Osaka City University,3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585 (Japan)

2016-11-17

We propose a new formalism to study the ABJM matrix model. Contrary to expressing the fractional brane background with the Wilson loops in the open string formalism, we formulate the Wilson loop expectation value from the viewpoint of the closed string background. With this new formalism, we can prove some duality relations in the matrix model. /includegraphics[scale=0.7]{abstract.eps}.

Probing N=2 superconformal field theories with localization

Energy Technology Data Exchange (ETDEWEB)

Fiol, Bartomeu [Departament de Física Fonamental i Institut de Ciències del Cosmos,Universitat de Barcelona,Martí i Franquès 1, 08028 Barcelona, Catalonia (Spain); Garolera, Blai [Escuela de Física, Universidad de Costa Rica,11501-2060 San José (Costa Rica); Torrents, Genís [Departament de Física Fonamental i Institut de Ciències del Cosmos,Universitat de Barcelona,Martí i Franquès 1, 08028 Barcelona, Catalonia (Spain)

2016-01-27

We use supersymmetric localization to study probes of four dimensional Lagrangian N=2 superconformal field theories. We first derive a unique equation for the eigenvalue density of these theories. We observe that these theories have a Wigner eigenvalue density precisely when they satisfy a necessary condition for having a holographic dual with a sensible higher-derivative expansion. We then compute in the saddle-point approximation the vacuum expectation value of 1/2-BPS circular Wilson loops, and the two-point functions of these Wilson loops with the Lagrangian density and with the stress-energy tensor. This last computation also provides the corresponding Bremsstrahlung functions and entanglement entropies. As expected, whenever a finite fraction of the matter is in the fundamental representation, the results are drastically different from those of N=4 supersymmetric Yang-Mills theory.

Mowat-Wilson syndrome: neurological and molecular study in seven patients

Directory of Open Access Journals (Sweden)

José Albino da Paz

2015-01-01

Full Text Available Objective To present a seven-cases serie of Mowat-Wilson syndrome (MWS. Method All patients with positive mutation for the ZEB2 were evaluated by a geneticist and a neurologist, with clinical and laboratorial characterization. Results A peculiar facies and mental retardation were present in all patients. The Denver II scale showed intense delay in all aspects, especially fine motor and adaptive. Acquired microcephaly was observed in five patients. Only one patient did not present epilepsy. Epilepsy was focal and predominating in sleep, with status epilepticus in three patients. The initial seizure was associated with fever in most patients (4/6. The EEG showed epileptic focal activity (5/7. The imaging studies revealed total agenesis (4/7 and partial agenesis of the corpus callosum (1/7. Conclusion Physicians who care for patients with mental retardation and epilepsy should be aware of SMW.

Chiral symmetry breaking and the Banks-Casher relation in lattice QCD with Wilson quarks

CERN Document Server

Giusti, Leonardo

2009-01-01

The Banks--Casher relation links the spontaneous breaking of chiral symmetry in QCD to the presence of a non-zero density of quark modes at the low end of the spectrum of the Dirac operator. Spectral observables like the number of modes in a given energy interval are renormalizable and can therefore be computed using the Wilson formulation of lattice QCD even though the latter violates chiral symmetry at energies on the order of the inverse lattice spacing. Using numerical simulations, we find (in two-flavour QCD) that the low quark modes do condense in the expected way. In particular, the chiral condensate can be accurately calculated simply by counting the low modes on large lattices. Other spectral observables can be considered as well and have a potentially wide range of uses.

Local anomaly cancellation in heterotic E8 x E8 orbifold compactifications with Wilson line backgrounds

International Nuclear Information System (INIS)

Walter, M.G.A.

2004-02-01

We consider several examples of a special class of heterotic compactifications, i.e. heterotic E 8 x E 8 orbifolds with Wilson line backgrounds. By developing a local perspective we show that a brane world like picture emerges. As an important result we prove that the local massless spectrum at such a brane can always be traced back to the global spectrum of a (different) orbifold without Wilson lines. One particular implication of this result is that the use of (discrete) Wilson lines for the construction of phenomenologically interesting models has to be rethought. We show that stringy constraints render the brane spectra consistent. Using our local picture we are able to compute the local anomalies appearing at the different branes for our examples and show that they can all be cancelled by a local version of the Green-Schwarz mechanism at the same time. (orig.)

Perturbations in loop quantum cosmology

International Nuclear Information System (INIS)

Nelson, W; Agullo, I; Ashtekar, A

2014-01-01

The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the theory. For this to be possible, we need a detailed understanding of the generation and evolution of inhomogeneous perturbations during the early, quantum gravity phase of the universe. Here, we have described how Loop Quantum Cosmology provides a completion of the inflationary paradigm, that is consistent with the observed power spectra of the CMB

Wilson cycle passive margins: Control of orogenic inheritance on continental breakup

DEFF Research Database (Denmark)

Petersen, Kenni D.; Schiffer, Christian

2016-01-01

Abstract Rifts and passive margins often develop along old suture zones where colliding continents merged during earlier phases of the Wilson cycle. For example, the North Atlantic formed after continental break-up along sutures formed during the Caledonian and Variscan orogenies. Even though suc...

Effective field theory of integrating out sfermions in the MSSM: Complete one-loop analysis

Science.gov (United States)

Huo, Ran

2018-04-01

We apply the covariant derivative expansion of the Coleman-Weinberg potential to the sfermion sector in the minimal supersymmetric standard model, matching it to the relevant dimension-6 operators in the standard model effective field theory at one-loop level. Emphasis is paid to nondegenerate large soft supersymmetry breaking mass squares, and the most general analytical Wilson coefficients are obtained for all pure bosonic dimension-6 operators. In addition to the non-logarithmic contributions, they generally have another logarithmic contributions. Various numerical results are shown, in particular the constraints in the large Xt branch reproducing the 125 GeV Higgs mass can be pushed to high values to almost completely probe the low stop mass region at the future FCC-ee experiment, even given the Higgs mass calculation uncertainty.

The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F{sub 2}(x,Q{sup 2}) and transversity

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Behring, A.; 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)

2014-09-15

We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F{sub 2}(x,Q{sup 2}) in the asymptotic region Q{sup 2}≫m{sup 2} and the associated operator matrix element A{sub qq,Q}{sup (3),NS}(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(N{sub F}) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F{sub 2}(x,Q{sup 2})

Light quark masses with Nf = 2 Wilson fermions

International Nuclear Information System (INIS)

Eicker, N.; Lippert, Th.; Orth, B.; Schilling, K.

2002-01-01

We present new data on the mass of the light and strange quarks from SESAM/TχL. The results were obtained on lattice-volumes of 16 3 x 32 and 24 3 x 40 points, with the possibility to investigate finite-size effects. Since the SESAM/TχL ensembles at β = 5.6 have been complemented by configurations with β = 5.5, moreover, we are now able to attempt the continuum extrapolation (CE) of the quark masses with standard Wilson fermions

Heating mechanisms for intermittent loops in active region cores from AIA/SDO EUV observations

Energy Technology Data Exchange (ETDEWEB)

Cadavid, A. C.; Lawrence, J. K.; Christian, D. J. [Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330 (United States); Jess, D. B. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Nigro, G. [Universita della Calabria, Dipartimento di Fisica and Centro Nazionale Interuniversitario Struttura della Materia, Unita di Cosenza, I-87030 Arcavacata di Rende (Italy)

2014-11-01

We investigate intensity variations and energy deposition in five coronal loops in active region cores. These were selected for their strong variability in the AIA/SDO 94 Å intensity channel. We isolate the hot Fe XVIII and Fe XXI components of the 94 Å and 131 Å by modeling and subtracting the 'warm' contributions to the emission. HMI/SDO data allow us to focus on 'inter-moss' regions in the loops. The detailed evolution of the inter-moss intensity time series reveals loops that are impulsively heated in a mode compatible with a nanoflare storm, with a spike in the hot 131 Å signals leading and the other five EUV emission channels following in progressive cooling order. A sharp increase in electron temperature tends to follow closely after the hot 131 Å signal confirming the impulsive nature of the process. A cooler process of growing emission measure follows more slowly. The Fourier power spectra of the hot 131 Å signals, when averaged over the five loops, present three scaling regimes with break frequencies near 0.1 min{sup –1} and 0.7 min{sup –1}. The low frequency regime corresponds to 1/f noise; the intermediate indicates a persistent scaling process and the high frequencies show white noise. Very similar results are found for the energy dissipation in a 2D 'hybrid' shell model of loop magneto-turbulence, based on reduced magnetohydrodynamics, that is compatible with nanoflare statistics. We suggest that such turbulent dissipation is the energy source for our loops.

A conditioning technique for matrix inversion for Wilson fermions

International Nuclear Information System (INIS)

DeGrand, T.A.

1988-01-01

I report a simple technique for conditioning conjugate gradient or conjugate residue matrix inversion as applied to the lattice gauge theory problem of computing the propagator of Wilson fermions. One form of the technique provides about a factor of three speedup over an unconditioned algorithm while running at the same speed as an unconditioned algorithm. I illustrate the method as it is applied to a conjugate residue algorithm. (orig.)

On the one loop γ(∗)→qq̄ impact factor and the exclusive diffractive cross sections for the production of two or three jets

International Nuclear Information System (INIS)

Boussarie, R.; Grabovsky, A.V.; Szymanowski, L.; Wallon, S.

2016-01-01

We present the calculation of the impact factor for the γ (∗) →qq̄ transition with one loop accuracy in arbitrary kinematics. The calculation was done within Balitsky’s high energy operator expansion. Together with our previous result for the γ (∗) →qq̄g Born impact factor it allows one to derive cross sections for 2- (one loop) and 3-jet (Born) difractive electroproduction. We write such cross sections for the 2 and 3 jet exclusive diffractive electroproduction off a proton in terms of hadronic matrix elements of Wilson lines. For the 2-jet cross section we demonstrate the cancellation of infrared, collinear and rapidity singularities. Our result can be directly exploited to describe the recently analyzed data on exclusive dijet production at HERA and used for the study of jet photoproduction in ultraperipheral proton or nuclear scattering.

String dynamics in QCD

International Nuclear Information System (INIS)

Gervais, J.L.; Neveu, A.

1980-01-01

Recent works of the authors on string interpretation of the Wilson loop operators in QCD are reviewed in a self-contained fashion. Although most of the results habe already appeared in print, some new material is presented in renormalization of the Wilson loop operator and on the use of light-cone expansion to derive a linear string-like equation in light-cone formalism. (orig.)

Supersymmetric Yang-Mills and supergravity amplitudes at one loop

International Nuclear Information System (INIS)

Hall, Anthony

2009-01-01

By applying the known expressions for super Yang-Mills (SYM) and supergravity (SUGRA) tree amplitudes, we write generating functions for the next-to-next-to-maximally helicity violating (NNMHV) box coefficients of SYM as well as the maximally helicity violating, next-to-maximally helicity violating, and NNMHV box coefficients for SUGRA. The all-multiplicity generating functions utilize covariant, on-shell superspace whereby the contribution from arbitrary external states in the supermultiplet can be extracted by Grassmann operators. In support of the relation between dual-Wilson loops and SYM scattering amplitudes at weak coupling, the SYM amplitudes are presented in a manifestly dual superconformal form. We introduce ordered box coefficients for calculating SUGRA quadruple cuts and prove that ordered coefficients generate physical cut amplitudes after summing over permutations of the external legs. The ordered box coefficients are produced by sewing ordered subamplitudes, previously used in applying on-shell recursion relations at tree level. We describe our verification of the results against the literature, and a formula for extracting the contributions from external gluons or gravitons to NNMHV superamplitudes is presented.

Loop Transfer Matrix and Loop Quantum Mechanics

International Nuclear Information System (INIS)

Savvidy, George K.

2000-01-01

The gonihedric model of random surfaces on a 3d Euclidean lattice has equivalent representation in terms of transfer matrix K(Q i ,Q f ), which describes the propagation of loops Q. We extend the previous construction of the loop transfer matrix to the case of nonzero self-intersection coupling constant κ. We introduce the loop generalization of Fourier transformation which allows to diagonalize transfer matrices, that depend on symmetric difference of loops only and express all eigenvalues of 3d loop transfer matrix through the correlation functions of the corresponding 2d statistical system. The loop Fourier transformation allows to carry out the analogy with quantum mechanics of point particles, to introduce conjugate loop momentum P and to define loop quantum mechanics. We also consider transfer matrix on 4d lattice which describes propagation of memebranes. This transfer matrix can also be diagonalized by using the generalized Fourier transformation, and all its eigenvalues are equal to the correlation functions of the corresponding 3d statistical system. In particular the free energy of the 4d membrane system is equal to the free energy of 3d gonihedric system of loops and is equal to the free energy of 2d Ising model. (author)

Segment-based Eyring-Wilson viscosity model for polymer solutions

International Nuclear Information System (INIS)

Sadeghi, Rahmat

2005-01-01

A theory-based model is presented for correlating viscosity of polymer solutions and is based on the segment-based Eyring mixture viscosity model as well as the segment-based Wilson model for describing deviations from ideality. The model has been applied to several polymer solutions and the results show that it is reliable both for correlation and prediction of the viscosity of polymer solutions at different molar masses and temperature of the polymer

Corrections to the Banks-Casher relation with Wilson quarks

CERN Document Server

Necco, S

2013-01-01

The Banks-Casher relation links the spectral density of the Dirac operator with the existence of a chiral condensate and spontaneous breaking of chiral symmetry. This relation receives corrections from a finite value of the quark mass, a finite space-time volume and, if evaluated on a discrete lattice, from the finite value of the lattice spacing a. We present a status report of a determination of these corrections for Wilson quarks.

On the one loop γ{sup (∗)}→qq̄ impact factor and the exclusive diffractive cross sections for the production of two or three jets

Energy Technology Data Exchange (ETDEWEB)

Boussarie, R. [Laboratoire de Physique Théorique, UMR 8627, CNRS, University Paris-Sud, CNRS,Université Paris-Saclay,91405, Orsay (France); Grabovsky, A.V. [Budker Institute of Nuclear Physics,11, Lavrenteva avenue, 630090, Novosibirsk (Russian Federation); Novosibirsk State University,630090, 2, Pirogova street, Novosibirsk (Russian Federation); Department of Physics, University of Minnesota,Duluth, Minnesota, 55812 (United States); Szymanowski, L. [National Centre for Nuclear Research (NCBJ),Warsaw (Poland); Wallon, S. [Laboratoire de Physique Théorique, UMR 8627, CNRS, University Paris-Sud, CNRS,Université Paris-Saclay,91405, Orsay (France); UPMC University Paris 06, faculté de physique,4 place Jussieu, 75252 Paris Cedex 05 (France)

2016-11-24

We present the calculation of the impact factor for the γ{sup (∗)}→qq̄ transition with one loop accuracy in arbitrary kinematics. The calculation was done within Balitsky’s high energy operator expansion. Together with our previous result for the γ{sup (∗)}→qq̄g Born impact factor it allows one to derive cross sections for 2- (one loop) and 3-jet (Born) difractive electroproduction. We write such cross sections for the 2 and 3 jet exclusive diffractive electroproduction off a proton in terms of hadronic matrix elements of Wilson lines. For the 2-jet cross section we demonstrate the cancellation of infrared, collinear and rapidity singularities. Our result can be directly exploited to describe the recently analyzed data on exclusive dijet production at HERA and used for the study of jet photoproduction in ultraperipheral proton or nuclear scattering.

College Board Response to "Harvard Educational Review" Article by Santelices and Wilson

Science.gov (United States)

College Board, 2010

2010-01-01

This is the College Board's response to a research article by Drs. Maria Veronica Santelices and Mark Wilson in the Harvard Educational Review, entitled "Unfair Treatment? The Case of Freedle, the SAT, and the Standardization Approach to Differential Item Functioning" (see EJ930622).

Wilson Fermions and Axion Electrodynamics in Optical Lattices

International Nuclear Information System (INIS)

Bermudez, A.; Martin-Delgado, M. A.; Mazza, L.; Rizzi, M.; Goldman, N.; Lewenstein, M.

2010-01-01

We show that ultracold Fermi gases in optical superlattices can be used as quantum simulators of relativistic lattice fermions in 3+1 dimensions. By exploiting laser-assisted tunneling, we find an analogue of the so-called naive Dirac fermions, and thus provide a realization of the fermion doubling problem. Moreover, we show how to implement Wilson fermions, and discuss how their mass can be inverted by tuning the laser intensities. In this regime, our atomic gas corresponds to a phase of matter where Maxwell electrodynamics is replaced by axion electrodynamics: a 3D topological insulator.

Weighing black holes using open-loop focus corrections for LGS-AO observations of galaxy nuclei at Gemini Observatory

Science.gov (United States)

McDermid, Richard M.; Krajnovic, Davor; Cappellari, Michele; Trujillo, Chadwick; Christou, Julian; Davies, Roger L.

2010-07-01

We present observations of early-type galaxies with laser guide star adaptive optics (LGS AO) obtained at Gemini North telescope using the NIFS integral field unit (IFU). We employ an innovative technique where the focus compensation due to the changing distance to the sodium layer is made 'open loop', allowing the extended galaxy nucleus to be used only for tip-tilt correction. The purpose of these observations is to determine high spatial resolution stellar kinematics within the nuclei of these galaxies to determine the masses of the super-massive black holes. The resulting data have spatial resolution of 0.2" FWHM or better. This is sufficient to positively constrain the presence of the central black hole in even low-mass early-type galaxies, suggesting that larger samples of such objects could be observed with this technique in the future. The open-loop focus correction technique is a supported queue-observing mode at Gemini, significantly extending the sky coverage in particular for faint, extended guide sources. We also provide preliminary results from tests combining tip/tilt correction from the Gemini peripheral guider with on-axis LGS. The current test system demonstrates feasibility of this mode, providing about a factor 2-3 improvement over natural seeing. With planned upgrades to the peripheral wave-front sensor, we hope to provide close to 100% sky coverage with low Strehl corrections, or 'improved seeing', significantly increasing flux concentration for deep field and extended object studies.

Stability, structure, and evolution of cool loops

International Nuclear Information System (INIS)

Cally, P.S.; Robb, T.D.

1991-01-01

The criteria for the existence and stability of cool loops are reexamined. It is found that the stability of the loops strongly depends on the form of the heating and radiative loss functions and that if the Ly-alpha peak which appears in most calculations of the radiative loss function is real, cool loops are almost certainly unstable. Removing the hydrogen contribution from the recent loss function Q(T) by Cook et al. (1989) does not produce the much-used result, Q proportional to T-cubed, which is so favorable to cool loop stability. Even using the probably unrealistically favorable loss function Q1 of Cook et al. with the hydrogen contribution removed, the maximum temperature attainable in stable cool loops is a factor of 2-3 too small to account for the excess emission observed in lower transition region lines. Dynamical simulations of cool loop instabilities reveal that the final state of such a model is the hot loop equilibrium. 26 refs

Fundamental and Harmonic Oscillations in Neighboring Coronal Loops

Science.gov (United States)

Li, Hongbo; Liu, Yu; Vai Tam, Kuan

2017-06-01

We present observations of multimode (fundamental and harmonic) oscillations in a loop system, which appear to be simultaneously excited by a GOES C-class flare. Analysis of the periodic oscillations reveals that (1) the primary loop with a period of P a ≈ 4 minutes and a secondary loop with two periods of P a ≈ 4 minutes and P b ≈ 2 minutes are detected simultaneously in closely spaced loop strands; (2) both oscillation components have their peak amplitudes near the loop apex, while in the second loop the low-frequency component P a dominates in a loop segment that is two times larger than the high-frequency component P b ; (3) the harmonic mode P b shows the largest deviation from a sinusoidal loop shape at the loop apex. We conclude that multiple harmonic modes with different displacement profiles can be excited simultaneously even in closely spaced strands, similar to the overtones of a violin string.

Some considerations in the splitting of interstitial frank loops formed by irradiation

International Nuclear Information System (INIS)

Seshan, K.; Grilhe, J.; Washburn, J.

1975-05-01

The splitting of interstitial loops formed by irradiation is considered in detail. It is shown that they may split to form obtuse--angled single shear faults on the intersecting (111) planes. A detailed description of the splitting is given in which the interstitial Frank loop is viewed as being made up of perfect dislocation loop and two shears. The detailed description is then considered in the context of the formation of complex loops as are observed in quenching and irradiation studies. Experimentally observed geometries are explained viz, triangular loops within hexagonal ones etc. The nucleation of a DC' loop in complex interstitial loop formation is shown to be feasible. DC' has the magnitude of a perfect dislocation loop and encloses an intrinsic shear

The Development of Field Guides for Birding: Gwillim, Wilson, Audubon and Peterson.

Science.gov (United States)

Cameron, Teddy

2000-01-01

Discusses the increasing interest of the public in nature and art of the 18th and 19th centuries, and making watercolor painting a part of the curriculum. Focuses on the works and publishing of Gwillim, Wilson, Audubon, and Peterson. (Contains 12 references.) (YDS)

Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

International Nuclear Information System (INIS)

Oe, Shinji; Miyagawa, Koichiro; Honma, Yuichi; Harada, Masaru

2016-01-01

Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

Energy Technology Data Exchange (ETDEWEB)

Oe, Shinji, E-mail: ooes@med.uoeh-u.ac.jp; Miyagawa, Koichiro, E-mail: koichiro@med.uoeh-u.ac.jp; Honma, Yuichi, E-mail: y-homma@med.uoeh-u.ac.jp; Harada, Masaru, E-mail: msrharada@med.uoeh-u.ac.jp

2016-09-10

Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

Biopolymer strategy for the treatment of Wilson´s disease

Czech Academy of Sciences Publication Activity Database

Vetrík, Miroslav; Mattová, J.; Macková, Hana; Kučka, Jan; Poučková, P.; Kukačková, Olivia; Brus, Jiří; Eigner-Henke, S.; Sedláček, Ondřej; Šefc, L.; Štěpánek, Petr; Hrubý, Martin

2018-01-01

Roč. 273, 10 March (2018), s. 131-138 ISSN 0168-3659 R&D Projects: GA ČR(CZ) GA16-02870S; GA MZd(CZ) NV15-25781A; GA MŠk(CZ) LM2015064; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : Wilson's disease * copper chelators * biopolymers Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.786, year: 2016

Standard model Wilson coefficients for c → ul{sup +}l{sup -} transitions at next-to-leading order

Energy Technology Data Exchange (ETDEWEB)

Boer, Stefan de [TU Dortmund (Germany); Mueller, Bastian; Seidel, Dirk [Uni Siegen (Germany)

2016-07-01

The standard theoretical framework to deal with exclusive, weak decays of heavy mesons is the so-called weak effective Hamiltonian. It involves the short-distance Wilson coefficients, which depend on the renormalization scale μ. For specific calculations one has to evolve the Wilson coefficients down from the electroweak scale μ{sub W} to the typical mass scale of the decay under consideration. This is done by solving a renormalization group equation for the effective operator basis. In this talk the results of a consistent two-step running of the c → ul{sup +}l{sup -} Wilson coefficients are presented. This running involves the intermediate scale μ{sub b} (with μ{sub W} > μ{sub b} > μ{sub c}) where the bottom quark is integrated out. All the matching coefficients and anomalous dimensions are taken to the required order by generalizing and extending results from b → s or s → d transitions available in the literature.

Natively unstructured loops differ from other loops.

Directory of Open Access Journals (Sweden)

Avner Schlessinger

2007-07-01

Full Text Available Natively unstructured or disordered protein regions may increase the functional complexity of an organism; they are particularly abundant in eukaryotes and often evade structure determination. Many computational methods predict unstructured regions by training on outliers in otherwise well-ordered structures. Here, we introduce an approach that uses a neural network in a very different and novel way. We hypothesize that very long contiguous segments with nonregular secondary structure (NORS regions differ significantly from regular, well-structured loops, and that a method detecting such features could predict natively unstructured regions. Training our new method, NORSnet, on predicted information rather than on experimental data yielded three major advantages: it removed the overlap between testing and training, it systematically covered entire proteomes, and it explicitly focused on one particular aspect of unstructured regions with a simple structural interpretation, namely that they are loops. Our hypothesis was correct: well-structured and unstructured loops differ so substantially that NORSnet succeeded in their distinction. Benchmarks on previously used and new experimental data of unstructured regions revealed that NORSnet performed very well. Although it was not the best single prediction method, NORSnet was sufficiently accurate to flag unstructured regions in proteins that were previously not annotated. In one application, NORSnet revealed previously undetected unstructured regions in putative targets for structural genomics and may thereby contribute to increasing structural coverage of large eukaryotic families. NORSnet found unstructured regions more often in domain boundaries than expected at random. In another application, we estimated that 50%-70% of all worm proteins observed to have more than seven protein-protein interaction partners have unstructured regions. The comparative analysis between NORSnet and DISOPRED2 suggested

DNA looping by FokI: the impact of twisting and bending rigidity on protein-induced looping dynamics

Science.gov (United States)

Laurens, Niels; Rusling, David A.; Pernstich, Christian; Brouwer, Ineke; Halford, Stephen E.; Wuite, Gijs J. L.

2012-01-01

Protein-induced DNA looping is crucial for many genetic processes such as transcription, gene regulation and DNA replication. Here, we use tethered-particle motion to examine the impact of DNA bending and twisting rigidity on loop capture and release, using the restriction endonuclease FokI as a test system. To cleave DNA efficiently, FokI bridges two copies of an asymmetric sequence, invariably aligning the sites in parallel. On account of the fixed alignment, the topology of the DNA loop is set by the orientation of the sites along the DNA. We show that both the separation of the FokI sites and their orientation, altering, respectively, the twisting and the bending of the DNA needed to juxtapose the sites, have profound effects on the dynamics of the looping interaction. Surprisingly, the presence of a nick within the loop does not affect the observed rigidity of the DNA. In contrast, the introduction of a 4-nt gap fully relaxes all of the torque present in the system but does not necessarily enhance loop stability. FokI therefore employs torque to stabilise its DNA-looping interaction by acting as a ‘torsional’ catch bond. PMID:22373924

Computational stability appraisal of rectangular natural circulation loop: Effect of loop inclination

International Nuclear Information System (INIS)

Krishnani, Mayur; Basu, Dipankar N.

2017-01-01

Highlights: • Computational model developed for single-phase rectangular natural circulation loop. • Role of loop inclination to vertical on thermalhydraulic stability is explored. • Inclination has strong stabilizing effect due to lower effective gravitation force. • Increase in tilt angle reduces settling time and highest amplitude of oscillation. • An angle of 15° is suggested for the selected loop geometry. - Abstract: Controlling stability behavior of single-phase natural circulation loops, without significantly affecting its steady-state characteristics, is a topic of wide research interest. Present study explores the role of loop inclination on a particular loop geometry. Accordingly a 3D computational model of a rectangular loop is developed and transient conservation equations are solved to obtain the temporal variation in flow parameters. Starting from the quiescent state, simulations are performed for selected sets of operating conditions and also with a few selected inclination angles. System experiences instability at higher heater powers and also with higher sink temperatures. Inclination is found to have a strong stabilizing influence owing to the reduction in the effective gravitational acceleration and subsequent decline in local buoyancy effects. The settling time and highest amplitude of oscillations substantially reduces for a stable system with a small inclination. Typically-unstable systems can also suppress the oscillations, when subjected to tilting, within a reasonable period of time. It is possible to stabilize the loop within shorter time span by increasing the tilt angle, but at the expense of reduction in steady-state flow rate. Overall a tilt angle of 15° is suggested for the selected geometry. Results from the 3D model is compared with the predictions from an indigenous 1D code. While similar qualitative influence of inclination is observed, the 1D model predicts early appearance of the stability threshold and hence hints

Loop kinematics

International Nuclear Information System (INIS)

Migdal, A.A.

1982-01-01

Basic operators acting in the loop space are introduced. The topology of this space and properties of the Stokes type loop functionals are discussed. The parametrically invariant loop calculus developed here is used in the loop dynamics

Mashup the OODA Loop

National Research Council Canada - National Science Library

Heier, Jeffrey E

2008-01-01

...) processes via the Observe, Orient, Decide, and Act (OODA) Loop concept. As defined by Wikipedia, a mashup is a Website or application that combines the content from more than one source into an integrated presentation...

UNRAVELLING THE COMPONENTS OF A MULTI-THERMAL CORONAL LOOP USING MAGNETOHYDRODYNAMIC SEISMOLOGY

Energy Technology Data Exchange (ETDEWEB)

Prasad, S. Krishna; Jess, D. B. [Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN (United Kingdom); Klimchuk, J. A. [Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD, 20771 (United States); Banerjee, D., E-mail: krishna.prasad@qub.ac.uk [Indian Institute of Astrophysics, II Block Koramangala, Bengaluru 560034 (India)

2017-01-10

Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite significant advances in observations and theory, our knowledge on the fundamental properties of these structures is limited. Here, we present unprecedented observations of accelerating slow magnetoacoustic waves along a coronal loop that show differential propagation speeds in two distinct temperature channels, revealing the multi-stranded and multithermal nature of the loop. Utilizing the observed speeds and employing nonlinear force-free magnetic field extrapolations, we derive the actual temperature variation along the loop in both channels, and thus are able to resolve two individual components of the multithermal loop for the first time. The obtained positive temperature gradients indicate uniform heating along the loop, rather than isolated footpoint heating.

Local anomaly cancellation in heterotic E{sub 8} x E{sub 8} orbifold compactifications with Wilson line backgrounds

Energy Technology Data Exchange (ETDEWEB)

Walter, M.G.A.

2004-02-01

We consider several examples of a special class of heterotic compactifications, i.e. heterotic E{sub 8} x E{sub 8} orbifolds with Wilson line backgrounds. By developing a local perspective we show that a brane world like picture emerges. As an important result we prove that the local massless spectrum at such a brane can always be traced back to the global spectrum of a (different) orbifold without Wilson lines. One particular implication of this result is that the use of (discrete) Wilson lines for the construction of phenomenologically interesting models has to be rethought. We show that stringy constraints render the brane spectra consistent. Using our local picture we are able to compute the local anomalies appearing at the different branes for our examples and show that they can all be cancelled by a local version of the Green-Schwarz mechanism at the same time. (orig.)

Wilson Dslash Kernel From Lattice QCD Optimization

Energy Technology Data Exchange (ETDEWEB)

Joo, Balint [Jefferson Lab, Newport News, VA; Smelyanskiy, Mikhail [Parallel Computing Lab, Intel Corporation, California, USA; Kalamkar, Dhiraj D. [Parallel Computing Lab, Intel Corporation, India; Vaidyanathan, Karthikeyan [Parallel Computing Lab, Intel Corporation, India

2015-07-01

Lattice Quantum Chromodynamics (LQCD) is a numerical technique used for calculations in Theoretical Nuclear and High Energy Physics. LQCD is traditionally one of the first applications ported to many new high performance computing architectures and indeed LQCD practitioners have been known to design and build custom LQCD computers. Lattice QCD kernels are frequently used as benchmarks (e.g. 168.wupwise in the SPEC suite) and are generally well understood, and as such are ideal to illustrate several optimization techniques. In this chapter we will detail our work in optimizing the Wilson-Dslash kernels for Intel Xeon Phi, however, as we will show the technique gives excellent performance on regular Xeon Architecture as well.

Constraining a Precambrian Wilson Cycle lifespan: An example from the ca. 1.8 Ga Nagssugtoqidian Orogen, Southeastern Greenland

Science.gov (United States)

Nicoli, Gautier; Thomassot, Emilie; Schannor, Mathias; Vezinet, Adrien; Jovovic, Ivan

2018-01-01

In the Phanerozoic, plate tectonic processes involve the fragmentation of the continental mass, extension and spreading of oceanic domains, subduction of the oceanic lithosphere and lateral shortening that culminate with continental collision (i.e. Wilson cycle). Unlike modern orogenic settings and despite the collection of evidence in the geological record, we lack information to identify such a sequence of events in the Precambrian. This is why it is particularly difficult to track plate tectonics back to 2.0 Ga and beyond. In this study, we aim to show that a multidisciplinary approach on a selected set of samples from a given orogeny can be used to place constraints on crustal evolution within a P-T-t-d-X space. We combine field geology, petrological observations, thermodynamic modelling (Theriak-Domino) and radiogenic (U-Pb, Lu-Hf) and stable isotopes (δ18O) to quantify the duration of the different steps of a Wilson cycle. For the purpose of this study, we focus on the Proterozoic Nagssugtoqidian Orogenic Belt (NOB), in the Tasiilaq area, South-East Greenland. Our study reveals that the Nagssugtoqidian Orogen was the result of a complete three stages juvenile crust production (Xjuv) - recycling/reworking sequence: (I) During the 2.60-2.95 Ga period, the Neoarchean Skjoldungen Orogen remobilised basement lithologies formed at TDM 2.91 Ga with progressive increase of the discharge of reworked material (Xjuv from 75% to 50%; δ18O: 4-8.5‰). (II) After a period of crustal stabilization (2.35-2.60 Ga), discrete juvenile material inputs (δ18O: 5-6‰) at TDM 2.35 Ga argue for the formation of an oceanic lithosphere and seafloor spreading over a period of 0.2 Ga (Xjuv from < 25% to 70%). Lateral shortening is set to have started at ca. 2.05 Ga with the accretion of volcanic/magmatic arcs (i.e. Ammassalik Intrusive Complex) and by subduction of small oceanic domains (M1: 520 ± 60 °C at 6.6 ± 1.4 kbar). (III) Continental collision between the North Atlantic

New solution for the Schwinger model

International Nuclear Information System (INIS)

Baaquie, B.E.

1980-08-01

We solve the Schwinger model exactly using the path integral. The fermion sector is solved using the axial current anomaly. We then study the Wilson loop integral for the interacting theory, and discuss the Wilson criterion for confinement. (author)

Potential of radiocopper in the diagnosis of Wilson disease

International Nuclear Information System (INIS)

Archambaud, F.; Yvart, J.; Moati, F.; Bernard, O.; Dommergues, J.P.; Desgrez, A.; Odievre, M.

1988-01-01

The purpose of the study is to establish if a simple test with 64 Cu is a valuable means of differenciating homozygotes for the ''Wilson's disease gene'' from heterozygous carriers and normal subjects for copper metabolism. A group of 73 subjects were studied. The only parameter which appears to be interesting is the percentage of administrated 64 Cu incorporated into ceruloplasmin at 48h. This test appears to be interesting to predict the disease and to avoid biopsy for determination of hepatic copper concentration [fr

Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae) da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae)

OpenAIRE

Takemoto, Ricardo Massato; Universidade Estadual de Matingá; Luque, José Luis; UFRRJ; Luque, José Luis; UFRRJ

2008-01-01

Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833), O. saurus (Bloch & Schneider, 1801) and O. saliens (Bloch, 1793) (Osteichthyes: Carangidae) from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908) are given. Caligus oligoplitisi Carvalho, 1954 is considered a new jun...

Wilson polynomials/functions and intertwining operators for the generic quantum superintegrable system on the 2-sphere

Science.gov (United States)

Miller, W., Jr.; Li, Q.

2015-04-01

The Wilson and Racah polynomials can be characterized as basis functions for irreducible representations of the quadratic symmetry algebra of the quantum superintegrable system on the 2-sphere, HΨ = EΨ, with generic 3-parameter potential. Clearly, the polynomials are expansion coefficients for one eigenbasis of a symmetry operator L2 of H in terms of an eigenbasis of another symmetry operator L1, but the exact relationship appears not to have been made explicit. We work out the details of the expansion to show, explicitly, how the polynomials arise and how the principal properties of these functions: the measure, 3-term recurrence relation, 2nd order difference equation, duality of these relations, permutation symmetry, intertwining operators and an alternate derivation of Wilson functions - follow from the symmetry of this quantum system. This paper is an exercise to show that quantum mechancal concepts and recurrence relations for Gausian hypergeometrc functions alone suffice to explain these properties; we make no assumptions about the structure of Wilson polynomial/functions, but derive them from quantum principles. There is active interest in the relation between multivariable Wilson polynomials and the quantum superintegrable system on the n-sphere with generic potential, and these results should aid in the generalization. Contracting function space realizations of irreducible representations of this quadratic algebra to the other superintegrable systems one can obtain the full Askey scheme of orthogonal hypergeometric polynomials. All of these contractions of superintegrable systems with potential are uniquely induced by Wigner Lie algebra contractions of so(3, C) and e(2,C). All of the polynomials produced are interpretable as quantum expansion coefficients. It is important to extend this process to higher dimensions.

Wilson polynomials/functions and intertwining operators for the generic quantum superintegrable system on the 2-sphere

International Nuclear Information System (INIS)

Miller, W Jr; Li, Q

2015-01-01

The Wilson and Racah polynomials can be characterized as basis functions for irreducible representations of the quadratic symmetry algebra of the quantum superintegrable system on the 2-sphere, HΨ = EΨ, with generic 3-parameter potential. Clearly, the polynomials are expansion coefficients for one eigenbasis of a symmetry operator L 2 of H in terms of an eigenbasis of another symmetry operator L 1 , but the exact relationship appears not to have been made explicit. We work out the details of the expansion to show, explicitly, how the polynomials arise and how the principal properties of these functions: the measure, 3-term recurrence relation, 2nd order difference equation, duality of these relations, permutation symmetry, intertwining operators and an alternate derivation of Wilson functions - follow from the symmetry of this quantum system. This paper is an exercise to show that quantum mechancal concepts and recurrence relations for Gausian hypergeometrc functions alone suffice to explain these properties; we make no assumptions about the structure of Wilson polynomial/functions, but derive them from quantum principles. There is active interest in the relation between multivariable Wilson polynomials and the quantum superintegrable system on the n-sphere with generic potential, and these results should aid in the generalization. Contracting function space realizations of irreducible representations of this quadratic algebra to the other superintegrable systems one can obtain the full Askey scheme of orthogonal hypergeometric polynomials. All of these contractions of superintegrable systems with potential are uniquely induced by Wigner Lie algebra contractions of so(3, C) and e(2,C). All of the polynomials produced are interpretable as quantum expansion coefficients. It is important to extend this process to higher dimensions. (paper)

Excitation and damping of transversal oscillation in coronal loops by wake phenomena

Directory of Open Access Journals (Sweden)

A abedini

2018-02-01

Full Text Available Transversal oscillation of coronal loops that are interpreted as signatures of magneto hydrodynamics (MHD waves are observed frequently in active region corona loops. The amplitude of this oscillation has been found to be strongly attenuated. The damping of transverse oscillation may be produced by the dissipation mechanism and the wake of the traveling disturbance. The damping of transversal loop oscillations with wake phenomena is not related to any dissipation mechanism. Also, these kinds of coronal loop oscillations are not related to the kink mode, although this mode can be occurred after the attenuation process by the energy of the wave packet deposited in the loop.  In this paper the excitation and damping of transversal coronal loop oscillations with wake of traveling wave packet is discussed in detail, both theoretically and observationally. Here, the transversal coronal loop oscillations is modeled with a one dimensional simple line-tied. The dynamics of the loop and the coronal is governed by the Klein–Gordon differential equation. A localized disturbance that can be generated by nearby flare produces a perturbation that undergoes dispersion as it propagates toward the loop. As a consequence, the amplitudes of oscillates decay with time roughly t-1/2 at the external cutoff frequency. These observed data on 2016-Dec-4 by Atmospheric Imaging Assembly (AIA onboard Solar Dynamic Observatory (SDO observations data, consisting of 560 images with an interval of 24 seconds in the 171 A0 pass band is analyzed for evidence of excitation and damping of transverse oscillations of coronal loop that is situated near a flare. In this analyzed signatures of transverse oscillations that are damped rapidly were found, with periods in the range of P=18.5-23.85 minutes. Furthermore, oscillation of loop segments attenuate with time roughly as t-α that average values of α for 4 different loops change form 0.65-0.80. The magnitude values of α are in

Insights into Wilson's Warbler migration from analyses of hydrogen stable-isotope ratios

Science.gov (United States)

Jeffrey F. Kelly; Viorel Atudorei; Zachary D. Sharp; Deborah M. Finch

2002-01-01

Our ability to link the breeding locations of individual passerines to migration stopover sites and wintering locations is limited. Stable isotopes of hydrogen contained in bird feathers have recently shown potential in this regard. We measured hydrogen stable-isotope ratios (deltaD) of feathers from breeding, migrating, and wintering Wilson's Warblers. Analyses...

Free convection in a partially submerged fluid loop

International Nuclear Information System (INIS)

Britt, T.E.; Wood, D.C.

1982-01-01

Several natural convection loop systems are studied in order to determine the operational characteristics for a multiple loop container which is used to cool failed nuclear reactor assemblies. Both analytical and experimental studies were undertaken to examine flow in both circular and rectangular flow loops. It was found that when a circular loop is heated at the bottom and cooled at the top, recirculation cells form at all input power fluxes. At fluxes between 0.1 W/cm 2 and 0.7 W/cm 2 the cells caused flow oscillations and reversals. With the circular loop heated from the side, no recirculation cells were observed at the power fluxes up to 1.5 W/cm. Boiling did not occur in the circular loop. For a rectangular loop heated and cooled on its vertical sides, no recirculation cells or flow reversals were seen. At input power fluxes above 1.2 W/cm 2 , periodic boiling in the heated side caused flow oscillations

Renormalisation constants of quark bilinears in lattice QCD with four dynamical Wilson quarks

NARCIS (Netherlands)

Blossier, B.; Brinet, M.; Carrasco, N.; Dimopoulos, P.; Du, X.; Frezzotti, R.; Gimenez, V.; Herdoiza, G.; Jansen, K.; Lubicz, V.; Palao, D.; Pallante, E.; Pene, O.; Petrov, K.; Reker, S.; Rossi, G. C.; Sanfilippo, F.; Scorzato, L.; Simula, S.; Urbach, C.

2011-01-01

We present preliminary results of the non-perturbative computation of the RI-MOM renormalisation constants in a mass-independent scheme for the action with Iwasaki glue and four dynamical Wilson quarks employed by ETMC. Our project requires dedicated gauge ensembles with four degenerate sea quark

Two loop virtual corrections to b → (d, s)l{sup +}l{sup -} and c → ul{sup +}l{sup -} for arbitrary momentum transfer

Energy Technology Data Exchange (ETDEWEB)

Boer, Stefan de [TU Dortmund, Fakultaet fuer Physik, Dortmund (Germany)

2017-11-15

Non-factorizable two loop corrections to heavy to light flavor changing neutral current transitions due to matrix elements of current-current operators are calculated analytically for arbitrary momentum transfer. This extends previous work on b → (d, s)l{sup +}l{sup -} transitions. New results for c → ul{sup +}l{sup -} transitions are presented. Recent work on polylogarithms is used for the master integrals. For b → sl{sup +}l{sup -} transitions, the corrections are most significant for the imaginary parts of the effective Wilson coefficients in the large hadronic recoil range. Analytical results and ready-to-use fitted results for a specific set of parameters are provided. (orig.)

Alternative loop rings

CERN Document Server

Goodaire, EG; Polcino Milies, C

1996-01-01

For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

Recursion relations for multi-gluon off-shell amplitudes on the light-front and Wilson lines

Directory of Open Access Journals (Sweden)

C. Cruz-Santiago

2015-06-01

Full Text Available We analyze the off-shell scattering amplitudes in the framework of the light-front perturbation theory. It is shown that the previously derived recursion relation between tree level off-shell amplitudes in this formalism actually resums whole classes of graphs into a Wilson line. More precisely, we establish a correspondence between the light-front methods for the computation of the off-shell amplitudes and the approach which makes use of the matrix elements of straight infinite Wilson lines, which are manifestly gauge invariant objects. Furthermore, since it is needed to explicitly verify the gauge invariance of light-front amplitudes, it is demonstrated that the Ward identities in this framework need additional instantaneous terms in the light-front graphs.

Adaptive Multigrid Algorithm for the Lattice Wilson-Dirac Operator

International Nuclear Information System (INIS)

Babich, R.; Brower, R. C.; Rebbi, C.; Brannick, J.; Clark, M. A.; Manteuffel, T. A.; McCormick, S. F.; Osborn, J. C.

2010-01-01

We present an adaptive multigrid solver for application to the non-Hermitian Wilson-Dirac system of QCD. The key components leading to the success of our proposed algorithm are the use of an adaptive projection onto coarse grids that preserves the near null space of the system matrix together with a simplified form of the correction based on the so-called γ 5 -Hermitian symmetry of the Dirac operator. We demonstrate that the algorithm nearly eliminates critical slowing down in the chiral limit and that it has weak dependence on the lattice volume.

Mowat-Wilson-syndrom hos tre danske børn

DEFF Research Database (Denmark)

Nissen, Karin Bækgaard; Søndergaard, Charlotte; Thelle, Thomas

2011-01-01

Mowat-Wilson syndrome (MWS) is an autosomal dominant intellectual disability syndrome characterised by unique facial features and congenital anomalies such as Hirschsprung disease, congenital heart defects, corpus callosum agenesis and urinary tract anomalies. Some cases also present epilepsy......, growth retardation and microcephaly. The syndrome is caused by mutations or deletions of the ZEB2 gene at chromosome 2q22-q23. MWS was first described in 1998 and until now approximately 180 cases have been reported worldwide. We report the first three molecularly confirmed Danish cases with MWS....

Critical behavior of the Schwinger model with Wilson fermions

International Nuclear Information System (INIS)

Azcoiti, V.; Laliena, V.

1995-09-01

A detailed analysis, in the framework of the MFA approach, of the critical behaviour of the lattice Schwinger model with Wilson fermions on lattices up to 24 2 , through the study of the Lee-Yang zeros and the specific heat, is presented. Compelling evidence is found for a critical line ending at k= 0.25 at large β. Finite size scaling analysis on lattices 8 2 , 12 2 , 16 2 , 20 2 and 24 2 indicates a continuous transition. The hyper scaling relation is verified in the explored β region

Increased cerebral iron uptake in Wilson's disease : A (52)Fe-citrate PET study

NARCIS (Netherlands)

Bruehlmeier, M; Leenders, KL; Vontobel, P; Calonder, C; Antonini, A; Weindl, A

Toxicity of abundant copper is the main cause of brain and liver tissue damage in patients with Wilson's disease (WD). However, there is also evidence of a disturbed iron metabolism in this genetically determined disorder. This PET study was undertaken to assess cerebral iron metabolism in WD

Development of a closed and open loop solar tracker technology

Directory of Open Access Journals (Sweden)

Aurélio Gouvêa Melo

2017-05-01

Full Text Available Solar energy is among the renewable energy sources that received greater addition in installed capacity. However, it accounts for a small fraction of the energy matrix of most countries. Electric energy generation by solar systems can be improved through tracking. This work aimed to develop and compare a closed and an open loop solar tracking system. The closed loop system was developed using Light Dependent Resistors. An algorithm was developed for the open loop tracker as a function of the geometric relation between the sun and the photovoltaic module. A simulation was run to compare this algorithm with a system using tracking at fixed time intervals, for clear sky conditions, with different tracking parameters and for five different latitudes. No significant difference was observed between the proposed open loop tracking algorithm and the fixed time interval algorithm for the tracking parameters evaluated. The open and closed loop solar tracking systems were compared experimentally in Rio das Ostras, Brazil (22.49 °S 41.92° W. An average gain of 28.5% was observed for the open loop tracking system over a latitude tilted system and 33.0% for the closed loop tracking system.

3-D numerical simulations of coronal loops oscillations

Directory of Open Access Journals (Sweden)

M. Selwa

2009-10-01

Full Text Available We present numerical results of 3-D MHD model of a dipole active region field containing a loop with a higher density than its surroundings. We study different ways of excitation of vertical kink oscillations by velocity perturbation: as an initial condition, and as an impulsive excitation with a pulse of a given position, duration, and amplitude. These properties are varied in the parametric studies. We find that the amplitude of vertical kink oscillations is significantly amplified in comparison to horizontal kink oscillations for exciters located centrally (symmetrically below the loop, but not if the exciter is located a significant distance to the side of the loop. This explains why the pure vertical kink mode is so rarely observed in comparison to the horizontally polarized one. We discuss the role of curved magnetic field lines and the pulse overlapping at one of the loop's footpoints in 3-D active regions (AR's on the excitation and the damping of slow standing waves. We find that footpoint excitation becomes more efficient in 3-D curved loops than in 2-D curved arcades and that slow waves can be excited within an interval of time that is comparable to the observed one wave-period due to the combined effect of the pulse inside and outside the loop. Additionally, we study the effect of AR topology on the excitation and trapping of loop oscillations. We find that a perturbation acting directly on a single loop excites oscillations, but results in an increased leakage compared to excitation of oscillations in an AR field by an external source.

3-D numerical simulations of coronal loops oscillations

Directory of Open Access Journals (Sweden)

M. Selwa

2009-10-01

Full Text Available We present numerical results of 3-D MHD model of a dipole active region field containing a loop with a higher density than its surroundings. We study different ways of excitation of vertical kink oscillations by velocity perturbation: as an initial condition, and as an impulsive excitation with a pulse of a given position, duration, and amplitude. These properties are varied in the parametric studies. We find that the amplitude of vertical kink oscillations is significantly amplified in comparison to horizontal kink oscillations for exciters located centrally (symmetrically below the loop, but not if the exciter is located a significant distance to the side of the loop. This explains why the pure vertical kink mode is so rarely observed in comparison to the horizontally polarized one. We discuss the role of curved magnetic field lines and the pulse overlapping at one of the loop's footpoints in 3-D active regions (AR's on the excitation and the damping of slow standing waves. We find that footpoint excitation becomes more efficient in 3-D curved loops than in 2-D curved arcades and that slow waves can be excited within an interval of time that is comparable to the observed one wave-period due to the combined effect of the pulse inside and outside the loop. Additionally, we study the effect of AR topology on the excitation and trapping of loop oscillations. We find that a perturbation acting directly on a single loop excites oscillations, but results in an increased leakage compared to excitation of oscillations in an AR field by an external source.

Atomistic simulations of the formation of -component dislocation loops in α-zirconium

Energy Technology Data Exchange (ETDEWEB)

Dai, Cong, E-mail: dai.cong@queensu.ca; Balogh, Levente; Yao, Zhongwen; Daymond, Mark R., E-mail: mark.daymond@queensu.ca

2016-09-15

The formation of -component dislocation loops in α-Zr is believed to be responsible for the breakaway irradiation growth experimentally observed under high irradiation fluences. However, while -loop growth is well described by existing models, the atomic mechanisms responsible for the nucleation of -component dislocation loops are still not clear. In the present work, both interstitial and vacancy -type dislocation loops are initially equilibrated at different temperatures. Cascades simulations in the vicinity of the -type loops are then performed by selecting an atom as the primary knock-on atoms (PKAs) with different kinetic energies, using molecular dynamics simulations. No -component dislocation loop was formed in cascades simulations with a 10 keV PKA, but -component interstitial loops were observed after the interaction between discontinuous 50 keV PKAs and pre-existing -type interstitial loops. The comparisons of cascades simulations in volumes having pre-existing -type interstitial and vacancy loops suggest that the reaction between the PKAs and -type interstitial loops is responsible for the formation of -component interstitial loops.

Urinary excretion of radiocopper in presymptomatic and symptomatic Wilson's disease, heterozygotes and controls: its significance in diagnosis and management

Energy Technology Data Exchange (ETDEWEB)

Gibbs, K; Hanka, R; Walshe, J M [Cambridge Univ. (UK). Clinical School

1978-07-01

Radiocopper (/sup 64/Cu, /sup 67/Cu), given intravenously, has been used to study the pattern of excretion of copper in patients with presymptomatic, symptomatic and treated Wilson's disease, together with heterozygotes for the Wilson's disease gene and a control group of patients with a variety of neurological lesions mimicking wilson's disease. The most important radiochemical findings were as follows. Heterozygotes excreted less of the injected copper than controls both under basal conditions and after penicillamine. Presymptomatic patients excreted less radiocopper than heterozygotes after penicillamine although the excretion during the basal 24 hour period was very much greater. Patients with symptomatic Wilson's disease had by far the highest excretion of radiocopper in all three time periods which fell after treatment, pro rata with time, as had been found for stable copper. These results were subjected to computer analysis. There was no overlap between the various groups with the exception of a single control subject who had combined pyramidal and extrapyramidal system degeneration of obscure aetiology. This patient was classified by the computer as 'heterozygote'. These findings lend further support to the hypothesis that the loss of a single gene for copper balance can be detected with a high degree of accuracy and also that presymptomatic patients can be selected from a sibship for prophylactic treatment without the risk of subjecting healthy heterozygotes to unnecessary and potentially hazardous longterm therapy.

Metastable states and quasicycles in a stochastic Wilson-Cowan model of neuronal population dynamics

KAUST Repository

Bressloff, Paul C.

2010-01-01

We analyze a stochastic model of neuronal population dynamics with intrinsic noise. In the thermodynamic limit N→∞, where N determines the size of each population, the dynamics is described by deterministic Wilson-Cowan equations. On the other hand

78 FR 73559 - Moose-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton...

Science.gov (United States)

2013-12-06

...-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton National Park... is preparing a Comprehensive Management Plan and Environmental Impact Statement (EIS) for the Moose...; (2) distinguish the corridor's fundamental and other important resources and values; (3) clearly...

FAST CONTRACTION OF CORONAL LOOPS AT THE FLARE PEAK

International Nuclear Information System (INIS)

Liu Rui; Wang Haimin

2010-01-01

On 2005 September 8, a coronal loop overlying the active region NOAA 10808 was observed in TRACE 171 A to contract at ∼100 km s -1 at the peak of an X5.4-2B flare at 21:05 UT. Prior to the fast contraction, the loop underwent a much slower contraction at ∼6 km s -1 for about 8 minutes, initiating during the flare preheating phase. The sudden switch to fast contraction is presumably corresponding to the onset of the impulsive phase. The contraction resulted in the oscillation of a group of loops located below, with the period of about 10 minutes. Meanwhile, the contracting loop exhibited a similar oscillatory pattern superimposed on the dominant downward motion. We suggest that the fast contraction reflects a suddenly reduced magnetic pressure underneath due either to (1) the eruption of magnetic structures located at lower altitudes or to (2) the rapid conversion of magnetic free energy in the flare core region. Electrons accelerated in the shrinking trap formed by the contracting loop can theoretically contribute to a late-phase hard X-ray burst, which is associated with Type IV radio emission. To complement the X5.4 flare which was probably confined, a similar event observed in SOHO/EIT 195 A on 2004 July 20 in an eruptive, M8.6 flare is briefly described, in which the contraction was followed by the expansion of the same loop leading up to a halo coronal mass ejection. These observations further substantiate the conjecture of coronal implosion and suggest coronal implosion as a new exciter mechanism for coronal loop oscillations.

Varieties of Abelian mirror symmetry on ℝℙ{sup 2}×S{sup 1}

Energy Technology Data Exchange (ETDEWEB)

Mori, Hironori [Department of Physics, Graduate School of Science, Osaka University,Toyonaka, Osaka 560-0043 (Japan); Tanaka, Akinori [iTHES Research Group, RIKEN,Wako, Saitama 351-0198 (Japan)

2016-02-15

We study 3d mirror symmetry with loop operators, Wilson loop and Vortex loop, and multi-flavor mirror symmetry through utilizing the ℝℙ{sup 2}×S{sup 1} index formula. The key identity which makes the above description work well is the mod 2 version of the Fourier analysis, and we study such structure, the S-operation in the context of a SL(2,ℤ) action on 3d SCFTs. We observed that two types of the parity conditions basically associated with gauge symmetries which we call P-type and CP-type are interchanged under mirror symmetry. We will also comment on the T-operation.

Random walk loop soups and conformal loop ensembles

NARCIS (Netherlands)

van de Brug, T.; Camia, F.; Lis, M.

2016-01-01

The random walk loop soup is a Poissonian ensemble of lattice loops; it has been extensively studied because of its connections to the discrete Gaussian free field, but was originally introduced by Lawler and Trujillo Ferreras as a discrete version of the Brownian loop soup of Lawler and Werner, a

Heavy flavor DIS Wilson coefficients in the asymptotic regime

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Schneider, C. [Linz Univ. (AT). Research Inst. for Symbolic Computation (RISC); Bierenbaum, I. [CSIC-Universitat de Valencia (Spain). Inst. de Fisica Corpuscular; Bluemlein, J.; Hasselhuhn, A.; Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Klein, S. [RWTH Aachen (Germany). Inst. fuer Theoretische Teilchenphysik und Kosmologie

2010-07-15

We report on results for the heavy flavor contributions to F{sub 2}(x,Q{sup 2}) in the limit Q{sup 2}>>m{sup 2} at NNLO. By calculating the massive 3-loop operator matrix elements, we account for all but the power suppressed terms in m{sup 2}/Q{sup 2}. Recently, the calculation of fixed Mellin moments of all 3-loop massive operator matrix elements has been finished. We present new all-N results for the O(n{sub f})-terms, thereby confirming the corresponding parts of the 3-loop anomalous dimensions. Additionally, we report on first genuine 3-loop results of the ladder-type diagrams for general values of the Mellin variable N. (orig.)

Renormalization of loop functions for all loops

International Nuclear Information System (INIS)

Brandt, R.A.; Neri, F.; Sato, M.

1981-01-01

It is shown that the vacuum expectation values W(C 1 ,xxx, C/sub n/) of products of the traces of the path-ordered phase factors P exp[igcontour-integral/sub C/iA/sub μ/(x)dx/sup μ/] are multiplicatively renormalizable in all orders of perturbation theory. Here A/sub μ/(x) are the vector gauge field matrices in the non-Abelian gauge theory with gauge group U(N) or SU(N), and C/sub i/ are loops (closed paths). When the loops are smooth (i.e., differentiable) and simple (i.e., non-self-intersecting), it has been shown that the generally divergent loop functions W become finite functions W when expressed in terms of the renormalized coupling constant and multiplied by the factors e/sup -K/L(C/sub i/), where K is linearly divergent and L(C/sub i/) is the length of C/sub i/. It is proved here that the loop functions remain multiplicatively renormalizable even if the curves have any finite number of cusps (points of nondifferentiability) or cross points (points of self-intersection). If C/sub γ/ is a loop which is smooth and simple except for a single cusp of angle γ, then W/sub R/(C/sub γ/) = Z(γ)W(C/sub γ/) is finite for a suitable renormalization factor Z(γ) which depends on γ but on no other characteristic of C/sub γ/. This statement is made precise by introducing a regularization, or via a loop-integrand subtraction scheme specified by a normalization condition W/sub R/(C-bar/sub γ/) = 1 for an arbitrary but fixed loop C-bar/sub γ/. Next, if C/sub β/ is a loop which is smooth and simple except for a cross point of angles β, then W(C/sub β/) must be renormalized together with the loop functions of associated sets S/sup i//sub β/ = ]C/sup i/ 1 ,xxx, C/sup i//sub p/i] (i = 2,xxx,I) of loops C/sup i//sub q/ which coincide with certain parts of C/sub β/equivalentC 1 1 . Then W/sub R/(S/sup i//sub β/) = Z/sup i/j(β)W(S/sup j//sub β/) is finite for a suitable matrix Z/sup i/j

Electron acceleration and radiation signatures in loop coronal transients

Science.gov (United States)

Vlahos, L.; Gergely, T. E.; Papadopoulos, K.

1982-01-01

It is proposed that in loop coronal transients an erupting loop moves away from the solar surface, with a velocity exceeding the local Alfven speed, pushing against the overlying magnetic fields and driving a shock in the front of the moving part of the loop. Lower hybrid waves are excited at the shock front and propagate radially toward the center of the loop with phase velocity along the magnetic field that exceeds the thermal velocity. The lower hybrid waves stochastically accelerate the tail of the electron distribution inside the loop. The manner in which the accelerated electrons are trapped in the moving loop are discussed, and their radiation signature is estimated. It is suggested that plasma radiation can explain the power observed in stationary and moving type IV bursts.

Solar center-limb variation of the Ca II K line and the Wilson-Bappu effect

International Nuclear Information System (INIS)

Engvold, O.; Marstad, N.C.

1983-01-01

New observations of the quiet Sun Ca II K line center-to-limb (C-L) have been made. The separation of the K 2 intensity peaks, the K 1 intensity minima and the intermediate width W 0 (the Wilson-Bappu width) are presented. It is shown that the C-L variation of all three parameters can be accounted for as a dependence on chromospheric column mass. The corresponding Ca II K line with parameters of 41 late type stars are also shown to vary in accordance with the inferred chromospheric column mass of the stars. The solar C-L and the stellar variation of the widths ΔK 1 and W 0 are found to have nearly indentical factors of proportionality with respect to log (column mass)

Nonequilibrium Chromosome Looping via Molecular Slip Links

Science.gov (United States)

Brackley, C. A.; Johnson, J.; Michieletto, D.; Morozov, A. N.; Nicodemi, M.; Cook, P. R.; Marenduzzo, D.

2017-09-01

We propose a model for the formation of chromatin loops based on the diffusive sliding of molecular slip links. These mimic the behavior of molecules like cohesin, which, along with the CTCF protein, stabilize loops which contribute to organizing the genome. By combining 3D Brownian dynamics simulations and 1D exactly solvable nonequilibrium models, we show that diffusive sliding is sufficient to account for the strong bias in favor of convergent CTCF-mediated chromosome loops observed experimentally. We also find that the diffusive motion of multiple slip links along chromatin is rectified by an intriguing ratchet effect that arises if slip links bind to the chromatin at a preferred "loading site." This emergent collective behavior favors the extrusion of loops which are much larger than the ones formed by single slip links.

Wilson disease: more than meets the eye.

Science.gov (United States)

Kelly, Claire; Pericleous, Marinos

2018-02-15

Wilson disease is a rare but important disorder of copper metabolism, with a failure to excrete copper appropriately into bile. It is a multisystem condition with presentations across all branches of medicine. Diagnosis can be difficult and requires a high index of suspicion. It should be considered in unexplained liver disease particularly where neuropsychiatric features are also present. Treatments are available for all stages of disease. A particularly important presentation not to overlook is acute liver failure which carries a high mortality risk and may require urgent liver transplantation. Here, we provide an overview of this complex condition. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Mismanagement of Wilson's disease as psychotic disorder.

Science.gov (United States)

Bidaki, Reza; Zarei, Mina; Mirhosseini, S M Mahdy; Moghadami, Samar; Hejrati, Maral; Kohnavard, Marjan; Shariati, Behnam

2012-01-01

Wilson's disease (WD) or hepatolenticular degeneration is an inherited neurodegenerative disorder of copper metabolism (autosomal recessive, chromosome13). Psychiatric disorders in WD include dementia, characterized by mental slowness, poor concentration, and memory impairment. Symptoms may progress rapidly, especially in younger patients, but are more often gradual in development with periods of remission and exacerbation. Delusional disorder and schizophrenia-like psychosis are rare forms of psychiatric presentation. In this report, the patient with WD presented by psychosis symptoms and treated mistaken as schizophrenia for almost ten years. Although he has treated with antipsychotics, he had periods of remissions and relapses and never was symptoms free. Since psychosis can be the manifestation of medical diseases such as WD, overall view of these patients is necessary and medical diseases should be considered as a differential diagnosis.

3-loop heavy flavor corrections in deep-inelastic scattering with two heavy quark lines

International Nuclear Information System (INIS)

Ablinger, J.; Schneider, C.; Hasselhuhn, A.; Round, M.; Manteuffel, A. von

2014-07-01

We consider gluonic contributions to the heavy flavor Wilson coefficients at 3-loop order in QCD with two heavy quark lines in the asymptotic region Q 2 >> m 2 1(2) . Here we report on the complete result in the case of two equal masses m 1 =m 2 for the massive operator matrix element A (3) gg,Q , which contributes to the corresponding heavy flavor transition matrix element in the variable flavor number scheme. Nested finite binomial sums and iterated integrals over square-root valued alphabets emerge in the result for this quantity in N and x-space, respectively. We also present results for the case of two unequal masses for the flavor non-singlet OMEs and on the scalar integrals ic case of A (3) gg,Q , which were calculated without a further approximation. The graphs can be expressed by finite nested binomial sums over generalized harmonic sums, the alphabet of which contains rational letters in the ratio η=m 2 1 /m 2 2 .

Daily survival rate and habitat characteristics of nests of Wilson's Plover

Science.gov (United States)

Zinsser, Elizabeth; Sanders, Felicia J.; Gerard, Patrick D.; Jodice, Patrick G.R.

2017-01-01

We assessed habitat characteristics and measured daily survival rate of 72 nests of Charadrius wilsonia (Wilson's Plover) during 2012 and 2013 on South Island and Sand Island on the central coast of South Carolina. At both study areas, nest sites were located at slightly higher elevations (i.e., small platforms of sand) relative to randomly selected nearby unused sites, and nests at each study area also appeared to be situated to enhance crypsis and/or vigilance. Daily survival rate (DSR) of nests ranged from 0.969 to 0.988 among study sites and years, and the probability of nest survival ranged from 0.405 to 0.764. Flooding and predation were the most common causes of nest failure at both sites. At South Island, DSR was most strongly related to maximum tide height, which suggests that flooding and overwash may be common causes of nest loss for Wilson's Plovers at these study sites. The difference in model results between the 2 nearby study sites may be partially due to more-frequent flooding at Sand Island because of some underlying yet unmeasured physiographic feature. Remaining data gaps for the species include regional assessments of nest and chick survival and habitat requirements during chick rearing.

Variable Sampling Composite Observer Based Frequency Locked Loop and its Application in Grid Connected System

Directory of Open Access Journals (Sweden)

ARUN, K.

2016-05-01

Full Text Available A modified digital signal processing procedure is described for the on-line estimation of DC, fundamental and harmonics of periodic signal. A frequency locked loop (FLL incorporated within the parallel structure of observers is proposed to accommodate a wide range of frequency drift. The error in frequency generated under drifting frequencies has been used for changing the sampling frequency of the composite observer, so that the number of samples per cycle of the periodic waveform remains constant. A standard coupled oscillator with automatic gain control is used as numerically controlled oscillator (NCO to generate the enabling pulses for the digital observer. The NCO gives an integer multiple of the fundamental frequency making it suitable for power quality applications. Another observer with DC and second harmonic blocks in the feedback path act as filter and reduces the double frequency content. A systematic study of the FLL is done and a method has been proposed to design the controller. The performance of FLL is validated through simulation and experimental studies. To illustrate applications of the new FLL, estimation of individual harmonics from nonlinear load and the design of a variable sampling resonant controller, for a single phase grid-connected inverter have been presented.

The QED vacuum polarization function at four loops and the anomalous magnetic moment at five loops

International Nuclear Information System (INIS)

Baikov, P.

2013-07-01

The anomalous moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to five-loop level by numerical methods. Contributions to the muon anomalous magnetic moment from certain diagram classes are also accessible by alternative methods. In this paper we present the evaluation of contributions to the QCD corrections due to insertions of the vacuum polarization function at five-loop level.

The QED vacuum polarization function at four loops and the anomalous magnetic moment at five loops

Energy Technology Data Exchange (ETDEWEB)

Baikov, P. [Moscow State Univ. (Russian Federation). D.V. Skobeltsyn Inst. of Nuclear Physics; Maier, A. [Technische Univ. Muenchen, Garching (Germany). Physics Dept. T31; Marquard, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2013-07-15

The anomalous moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to five-loop level by numerical methods. Contributions to the muon anomalous magnetic moment from certain diagram classes are also accessible by alternative methods. In this paper we present the evaluation of contributions to the QCD corrections due to insertions of the vacuum polarization function at five-loop level.

Successive Two-sided Loop Jets Caused by Magnetic Reconnection between Two Adjacent Filamentary Threads

Energy Technology Data Exchange (ETDEWEB)

Tian, Zhanjun; Liu, Yu; Shen, Yuandeng [Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650216 (China); Elmhamdi, Abouazza; Kordi, Ayman S. [Department of Physics and Astronomy, King Saud University, P.O. Box 2455, 11451 (Saudi Arabia); Su, Jiangtao [University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Ying D., E-mail: ydshen@ynao.ac.cn [State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190 (China)

2017-08-20

We present observational analysis of two successive two-sided loop jets observed by the ground-based New Vacuum Solar Telescope and the space-borne Solar Dynamics Observatory . The two successive two-sided loop jets manifested similar evolution processes and both were associated with the interaction of two small-scale adjacent filamentary threads, magnetic emerging, and cancellation processes at the jet’s source region. High temporal and high spatial resolution observations reveal that the two adjacent ends of the two filamentary threads are rooted in opposite magnetic polarities within the source region. The two threads approached each other, and then an obvious brightening patch is observed at the interaction position. Subsequently, a pair of hot plasma ejections are observed heading in opposite directions along the paths of the two filamentary threads at a typical speed for two-sided loop jets of the order 150 km s{sup −1}. Close to the end of the second jet, we report the formation of a bright hot loop structure at the source region, which suggests the formation of new loops during the interaction. Based on the observational results, we propose that the observed two-sided loop jets are caused by magnetic reconnection between the two adjacent filamentary threads, largely different from the previous scenario that a two-sided loop jet is generated by magnetic reconnection between an emerging bipole and the overlying horizontal magnetic fields.

The Reflection Effect on the Eclipsing Binary by the Wilson and Devinney's Model and Russell and Merrill's Model

Directory of Open Access Journals (Sweden)

Seong Hee Choea

1992-06-01

Full Text Available The reflection effect on three types of eclipsing binaries has been analyzed Wilson and Devinney's model and Russell and Merrill's model. The reflection effect was displayed on the theoretical light curves for the various conditions using the Wilson and Devinney's light curve program. Two models were compared after the rectifing the theoretical light curves including the reflection effect with the Russell and Merrill's method. The result shows that two models have an agreement on the reflection effect just in cases of the small difference in temperature and albedo between two stars in the system.

Electron acceleration and radiation signatures in loop coronal transients

International Nuclear Information System (INIS)

Vlahos, L.; Gergely, T.E.; Papadopoulos, K.

1982-01-01

A model for electron aceleration in loop coronal transients is suggested. We propose that in these transients an erupting loop moves away from the solar surface, with a velocity greater than the local Alfven speed, pushing against the overlying magnetic fields and driving a shock in the front of the moving part of the loop. We suggest that lower hybrid waves are excited at the shock front and propagate radially toward the center of the loop with phase velocity along the magnetic field which exceeds the thermal velocity. The lower hybrid waves stochastically accelerate the tail of the electron distribution inside the loop. We discuss how the accelerated electrons are trapped in the moving loop and give a rough estimate of their radiation signature. We find that plasma radiation can explain the power observed in stationary and moving type IV bursts. We discuss some of the conditions under which moving or stationary type IV bursts are expected to be associated with loop coronal transients

High-temperature helium-loop facility

International Nuclear Information System (INIS)

Tokarz, R.D.

1981-09-01

The high-temperature helium loop is a facility for materials testing in ultrapure helium gas at high temperatures. The closed loop system is capable of recirculating high-purity helium or helium with controlled impurities. The gas loop maximum operating conditions are as follows: 300 psi pressure, 500 lb/h flow rate, and 2100 0 F temperature. The two test sections can accept samples up to 3.5 in. diameter and 5 ft long. The gas loop is fully instrumented to continuously monitor all parameters of loop operation as well as helium impurities. The loop is fully automated to operate continuously and requires only a daily servicing by a qualified operator to replenish recorder charts and helium makeup gas. Because of its versatility and high degree of parameter control, the helium loop is applicable to many types of materials research. This report describes the test apparatus, operating parameters, peripheral systems, and instrumentation system. The experimental capabilities and test conand presents the results that have been obtained. The study has been conducted using a four-phase approach. The first phase develops the solution to the steady-state radon-diffusion equation in one-dimensieered barriers; disposal charge analysis; analysis of spent fuel policy implementation; spent f water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Uranium concentrations in the sediments which were above detection limits ranged from 0.10 t 51.2 ppM. The mean of the logarithms of the uranium concentrations was 0.53. A group of high uranium concentrations occurs near the junctions of quadrangles AB, AC, BB, a 200 mK. In case 2), x-ray studies of isotopic phase separation in 3 He-- 4 He bcc solids were carried out by B. A. Fraass

Wilson Disease Protein ATP7B Utilizes Lysosomal Exocytosis to Maintain Copper Homeostasis

NARCIS (Netherlands)

Polishchuk, Elena V.; Concilli, Mafalda; Iacobacci, Simona; Chesi, Giancarlo; Pastore, Nunzia; Piccolo, Pasquale; Paladino, Simona; Baldantoni, Daniela; van IJzendoorn, Sven C. D.; Chan, Jefferson; Chang, Christopher J.; Amoresano, Angela; Pane, Francesca; Pucci, Piero; Tarallo, Antonietta; Parenti, Giancarlo; Brunetti-Pierri, Nicola; Settembre, Carmine; Ballabio, Andrea; Polishchuk, Roman S.

2014-01-01

Copper is an essential yet toxic metal and its overload causes Wilson disease, a disorder due to mutations in copper transporter ATP7B. To remove excess copper into the bile, ATP7B traffics toward canalicular area of hepatocytes. However, the trafficking mechanisms of ATP7B remain elusive. Here, we

Phenotype and genotype of 87 patients with Mowat-Wilson syndrome and recommendations for care

DEFF Research Database (Denmark)

Ivanovski, Ivan; Djuric, Olivera; Caraffi, Stefano Giuseppe

2018-01-01

PurposeMowat-Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to be...

Obituary: Peter Robert Wilson, 1929-2007

Science.gov (United States)

Snodgrass, Herschel B.

2009-01-01

It is with great sadness that I report the passing of Peter Robert Wilson, a well-known and well-loved figure in the solar physics community. Peter was on the faculty of the Department of Applied Mathematics at the University of Sydney for 39 years, and Chair of the department for 24 of these years. He was the author or co-author of more than 80 scientific research papers and a book, Solar and Stellar Activity Cycles (1994), published by Cambridge University Press. He died suddenly of a heart attack, at his home in Glebe, Australia, in the early morning of 11 November 2007. Peter was an organizer of, and participant in, many international conferences and workshops. He traveled extensively, holding visiting appointments at the University of Colorado (JILA), at Cambridge University, at the College de France (Paris), and at the California Institute of Technology [CalTech]. Most of his work was in the field of solar physics, but he also did some work on the philosophy of science and on tides. Peter came from a line of mathematicians. His father, Robert Wilson, immigrated to Australia from Glasgow in 1911, and became a mathematics teacher at Scotch College, a private school in Melbourne. There his name was changed to 'Bill' because 'Bob' was already taken." Peter's enjoyment of this story as characteristic of Australian academia (as any fan of Monty Python would understand) is indicative of his infectious sense of humor. In a similar vein, he claimed ancestry traced back to the eighteenth-century Scottish mathematician Alexander Wilson, Professor of Astronomy at the University of Glasgow. That Wilson is famous in the solar physics community for his discovery, known as the "Wilson Effect," of the photospheric depressions associated with sunspots. Peter himself could not resist writing a paper on this subject, and was delighted when the bait was taken by some less-informed colleagues who chided him for "naming an effect after himself." "Bill" Wilson married Naomi

Electromagnetic corrections to the hadronic vacuum polarization of the photon within QEDL and QEDM

DEFF Research Database (Denmark)

Della Morte, Michele; Bussone, Andrea; Janowski, Tadeusz

2018-01-01

degenerate flavors of nonperturbatively O(a)-improved Wilson fermions. We consider QEDL and QEDM to deal with the finite-volume zero modes. We compare results for the Wilson loops with exact analytical determinations. In addition we make sure that the volumes and photon masses used in QEDM...

Open boundary condition, Wilson flow and the scalar glueball mass

International Nuclear Information System (INIS)

Chowdhury, Abhishek; Harindranath, A.; Maiti, Jyotirmoy

2014-01-01

A major problem with periodic boundary condition on the gauge fields used in current lattice gauge theory simulations is the trapping of topological charge in a particular sector as the continuum limit is approached. To overcome this problem open boundary condition in the temporal direction has been proposed recently. One may ask whether open boundary condition can reproduce the observables calculated with periodic boundary condition. In this work we find that the extracted lowest glueball mass using open and periodic boundary conditions at the same lattice volume and lattice spacing agree for the range of lattice scales explored in the range 3 GeV≤(1/a)≤5 GeV. The problem of trapping is overcome to a large extent with open boundary and we are able to extract the glueball mass at even larger lattice scale ≈ 5.7 GeV. To smoothen the gauge fields we have used recently proposed Wilson flow which, compared to HYP smearing, exhibits better systematics in the extraction of glueball mass. The extracted glueball mass shows remarkable insensitivity to the lattice spacings in the range explored in this work, 3 GeV≤(1/a)≤5.7 GeV.

STATISTICS OF FLARING LOOPS OBSERVED BY NOBEYAMA RADIOHELIOGRAPH. II. SPECTRAL EVOLUTION

International Nuclear Information System (INIS)

Huang Guangli; Nakajima, Hiroshi

2009-01-01

The spectral evolution of solar microwave bursts is studied in 10 impulsive events with loop-like structures, which are selected in the flare list of Nobeyama Radioheliograph. Most events have a brighter and harder looptop (LT) with maximum time later than at least one of its two footpoints (FPs), and have a common feature of the spectral evolution in the LT and the two FPs. There are five simple impulsive bursts with a well known pattern of soft-hard-soft or soft-hard-harder (SHH). It is first found that the other five events have multiple subpeaks in their impulsive phase, and mostly have a new feature of hard-soft-hard (HSH) in each subpeak, but, the well known tendency of SHH is still maintained in the total spectral evolution of these events. All of these features in the spectral evolution of the 10 selected events are consistent with the full Sun observations of Nobeyama Radio Polarimeters in these events. The new feature of HSH may be explained by the thermal free-free emission before, during, and after these bursts, together with multiple injections of nonthermal electrons, while the SHH pattern in the total duration may be directly caused by the trapping effect.

X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

Energy Technology Data Exchange (ETDEWEB)

Toor, A [California Univ., Livermore (USA). Lawrence Livermore Lab.

1980-01-01

The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology.

X-ray characteristics of the Lupus Loop and SN1006 supernova remnants

International Nuclear Information System (INIS)

Toor, A.

1980-01-01

The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest X-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 100 keV) from our observation and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology. (orig.)

Cranial MRI in Wilson's disease

International Nuclear Information System (INIS)

Prayer, L.; Grimm, G.

1990-01-01

Thirty-eight patients with biochemically proven Wilson's disease underwent magnetic resonanceimaging (MRI) of the brain as well as neurological examinations. The patients were scanned using spin-echo (SE) sequences; the neurologist was looking for typical symptoms: Dysarthria, tremor, ataxia, rigidity/bradykinesia and chorea/dystonia. Pathological MR findings believed secondary to this uncommon inherited disorder of copper metabolism were found in twenty-two subjects. Focal abnormalities were seen in the lenticular, thalamic and caudate nuclei as well as in brain stem and white matter; these lesions were best demonstrated on T2-weighted sequences as hyperintense areas. In eight patients we found diffuse brain atrophy with consecutive widening of the ventricular system. Five subjects showed mild, nineteen severe neurologic deficits. Generally there was no correlation between MR findings and clinical neurological symptoms; the impairment of cell-metabolism causing functional alterations of the brain precedes morphological changes. During treatment with the copper chelator D-penicillamine there seemed to be a phased course of disease. Shortening of T1-relaxation due to paramagnetic influence of copper was not seen; a possible explanation could be intracellular deposition - a proton-electron-dipolar-dipolar-interaction would there for be impossible. (orig.)

Finite size effects in lattice QCD with dynamical Wilson fermions

Energy Technology Data Exchange (ETDEWEB)

Orth, B.

2004-06-01

Due to limited computing resources choosing the parameters for a full lattice QCD simulation always amounts to a compromise between the competing objectives of a lattice spacing as small, quarks as light, and a volume as large as possible. Aiming at pushing unquenched simulations with the standard Wilson action towards the computationally expensive regime of small quark masses, the GRAL project addresses the question whether computing time can be saved by sticking to lattices with rather modest numbers of grid sites and extrapolating the finite-volume results to the infinite volume (prior to the usual chiral and continuum extrapolations). In this context we investigate in this work finite-size effects in simulated light hadron masses. Understanding their systematic volume dependence may not only help saving computer time in light quark simulations with the Wilson action, but also guide future simulations with dynamical chiral fermions which for a foreseeable time will be restricted to rather small lattices. We analyze data from hybrid Monte Carlo simulations with the N{sub f} = 2 Wilson action at two values of the coupling parameter, {beta} = 5.6 (lattice spacing {alpha} {approx} 0.08 fm) and {beta} = 5.32144 ({alpha} {approx} 0.13 fm). The larger {beta} corresponds to the coupling used previously by SESAM/T{chi}L. The considered hopping parameters {kappa} = 0.1575, 0.158 (at the larger {beta}) and {kappa} = 0.1665 (at the smaller {beta}) correspond to quark masses of 85, 50 and 36% of the strange quark mass, respectively. At each quark mass we study at least three different lattice extents in the range from L = 10 to L = 24 (0.85-2.04 fm). Estimates of autocorrelation times in the stochastic updating process and of the computational cost of every run are given. For each simulated sea quark mass we calculate quark propagators and hadronic correlation functions in order to extract the pion, rho and nucleon masses as well as the pion decay constant and the quark mass

Automated Temperature and Emission Measure Analysis of Coronal Loops and Active Regions Observed with the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (SDO/AIA)

Science.gov (United States)

Aschwanden, Markus J.; Boerner, Paul; Schrijver, Carolus J.; Malanushenko, Anna

2013-03-01

We developed numerical codes designed for automated analysis of SDO/AIA image datasets in the six coronal filters, including: i) coalignment test between different wavelengths with measurements of the altitude of the EUV-absorbing chromosphere, ii) self-calibration by empirical correction of instrumental response functions, iii) automated generation of differential emission measure [DEM] distributions with peak-temperature maps [ T p( x, y)] and emission measure maps [ EM p( x, y)] of the full Sun or active region areas, iv) composite DEM distributions [d EM( T)/d T] of active regions or subareas, v) automated detection of coronal loops, and vi) automated background subtraction and thermal analysis of coronal loops, which yields statistics of loop temperatures [ T e], temperature widths [ σ T], emission measures [ EM], electron densities [ n e], and loop widths [ w]. The combination of these numerical codes allows for automated and objective processing of numerous coronal loops. As an example, we present the results of an application to the active region NOAA 11158, observed on 15 February 2011, shortly before it produced the largest (X2.2) flare during the current solar cycle. We detect 570 loop segments at temperatures in the entire range of log( T e)=5.7 - 7.0 K and corroborate previous TRACE and AIA results on their near-isothermality and the validity of the Rosner-Tucker-Vaiana (RTV) law at soft X-ray temperatures ( T≳2 MK) and its failure at lower EUV temperatures.

Long-period Intensity Pulsations in Coronal Loops Explained by Thermal Non-equilibrium Cycles

Energy Technology Data Exchange (ETDEWEB)

Froment, C.; Auchère, F.; Bocchialini, K.; Buchlin, E.; Solomon, J. [Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, F-91405 Orsay cedex (France); Aulanier, G. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France); Mikić, Z., E-mail: clara.froment@astro.uio.no [Predictive Science, Inc., San Diego, CA 92121 (United States)

2017-02-01

In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon that can occur when the heating is both highly stratified and quasi-constant. Unambiguous observational identification of TNE would thus permit us to strongly constrain heating scenarios. While TNE is currently the standard interpretation of coronal rain, the long-term periodic evolution predicted by simulations has never been observed. However, the detection of long-period intensity pulsations (periods of several hours) has been recently reported with the Solar and Heliospheric Observatory /EIT, and this phenomenon appears to be very common in loops. Moreover, the three intensity-pulsation events that we recently studied with the Solar Dynamics Observatory /Atmospheric Imaging Assembly (AIA) show strong evidence for TNE in warm loops. In this paper, a realistic loop geometry from linear force-free field (LFFF) extrapolations is used as input to 1D hydrodynamic simulations. Our simulations show that, for the present loop geometry, the heating has to be asymmetrical to produce TNE. We analyze in detail one particular simulation that reproduces the average thermal behavior of one of the pulsating loop bundle observed with AIA. We compare the properties of this simulation with those deduced from the observations. The magnetic topology of the LFFF extrapolations points to the presence of sites of preferred reconnection at one footpoint, supporting the presence of asymmetric heating. In addition, we can reproduce the temporal large-scale intensity properties of the pulsating loops. This simulation further strengthens the interpretation of the observed pulsations as signatures of TNE. This consequently provides important information on the heating localization and timescale for these loops.

Xenon oscillation tests in four-loop PWR cores

International Nuclear Information System (INIS)

Aoki, Norihiko; Osaka, Kenichi; Shimada, Shoichiro; Tochihara, Hiroshi; Machii, Seigo

1980-01-01

The Kansai Electric Power Co.'s OHI Unit 1 and 2 are the first 4-loop PWRs in Japan which use 17 x 17 fuel assemblies and have essentially the same plant parameters. A 4-loop core has larger core radius and higher power density than those of 2- or 3-loop cores, and is less stable for Xe oscillation. It is therefore important to confirm that Xe oscillations in radial direction are sufficiently stable in a 4-loop core. Radial and axial Xe oscillation tests were performed during the startup physics tests of OHI Unit 1 and 2; Xe oscillation was induced by perturbation of control rods and the Xe effect on power distribution observed periodically. The test results show that the transverse Xe oscillation in the 4-loop core is sufficiently stable and that the agreement between the measurement and the calculated prediction is good. (author)