Zero point energy of renormalized Wilson loops

International Nuclear Information System (INIS)

Hidaka, Yoshimasa; Pisarski, Robert D.

2009-01-01

The quark-antiquark potential, and its associated zero point energy, can be extracted from lattice measurements of the Wilson loop. We discuss a unique prescription to renormalize the Wilson loop, for which the perturbative contribution to the zero point energy vanishes identically. A zero point energy can arise nonperturbatively, which we illustrate by considering effective string models. The nonperturbative contribution to the zero point energy vanishes in the Nambu model, but is nonzero when terms for extrinsic curvature are included. At one loop order, the nonperturbative contribution to the zero point energy is negative, regardless of the sign of the extrinsic curvature term.

Large Wilson loop averages from the Schwinger-Dyson equation

International Nuclear Information System (INIS)

Xue Shesheng

1987-01-01

Using Schwinger-Dyson equations for the large Wilson loop in abelian lattice gauge theories, we evaluate the vacuum expectation values of the Wilson loop of sizes 1x2, 2x2, 2x3, and so on, from which the string tension is extracted. (orig.)

Scaling properties of Wilson loops pierced by P-vortices

DEFF Research Database (Denmark)

Dunn, Patrick; Greensite, Jeffrey Paul

2012-01-01

P-vortices, in an SU(N) lattice gauge theory, are excitations on the center-projected Z(N) lattice. We study the ratio of expectation values of SU(2) Wilson loops, on the unprojected lattice, linked to a single P-vortex, to that of Wilson loops which are not linked to any P-vortices. When...

Wilson loop's phase transition probed by non-local observable

Directory of Open Access Journals (Sweden)

Hui-Ling Li

2018-04-01

Full Text Available In order to give further insights into the holographic Van der Waals phase transition, it would be of great interest to investigate the behavior of Wilson loop across the holographic phase transition for a higher dimensional hairy black hole. We offer a possibility to proceed with a numerical calculation in order to discussion on the hairy black hole's phase transition, and show that Wilson loop can serve as a probe to detect a phase structure of the black hole. Furthermore, for a first order phase transition, we calculate numerically the Maxwell's equal area construction; and for a second order phase transition, we also study the critical exponent in order to characterize the Wilson loop's phase transition.

Conformal blocks from Wilson lines with loop corrections

Science.gov (United States)

Hikida, Yasuaki; Uetoko, Takahiro

2018-04-01

We compute the conformal blocks of the Virasoro minimal model or its WN extension with large central charge from Wilson line networks in a Chern-Simons theory including loop corrections. In our previous work, we offered a prescription to regularize divergences from loops attached to Wilson lines. In this paper, we generalize our method with the prescription by dealing with more general operators for N =3 and apply it to the identity W3 block. We further compute general light-light blocks and heavy-light correlators for N =2 with the Wilson line method and compare the results with known ones obtained using a different prescription. We briefly discuss general W3 blocks.

Supersymmetric partition functions and the three-dimensional A-twist

Energy Technology Data Exchange (ETDEWEB)

Closset, Cyril [Theory Department, CERN,CH-1211, Geneva 23 (Switzerland); Kim, Heeyeon [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, N2L 2Y5, Ontario (Canada); Willett, Brian [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106 (United States)

2017-03-14

We study three-dimensional N=2 supersymmetric gauge theories on M{sub g,p}, an oriented circle bundle of degree p over a closed Riemann surface, Σ{sub g}. We compute the M{sub g,p} supersymmetric partition function and correlation functions of supersymmetric loop operators. This uncovers interesting relations between observables on manifolds of different topologies. In particular, the familiar supersymmetric partition function on the round S{sup 3} can be understood as the expectation value of a so-called “fibering operator” on S{sup 2}×S{sup 1} with a topological twist. More generally, we show that the 3d N=2 supersymmetric partition functions (and supersymmetric Wilson loop correlation functions) on M{sub g,p} are fully determined by the two-dimensional A-twisted topological field theory obtained by compactifying the 3d theory on a circle. We give two complementary derivations of the result. We also discuss applications to F-maximization and to three-dimensional supersymmetric dualities.

Defect networks and supersymmetric loop operators

Energy Technology Data Exchange (ETDEWEB)

Bullimore, Mathew [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5 (Canada)

2015-02-10

We consider topological defect networks with junctions in A{sub N−1} Toda CFT and the connection to supersymmetric loop operators in N=2 theories of class S on a four-sphere. Correlation functions in the presence of topological defect networks are computed by exploiting the monodromy of conformal blocks, generalising the notion of a Verlinde operator. Concentrating on a class of topological defects in A{sub 2} Toda theory, we find that the Verlinde operators generate an algebra whose structure is determined by a set of generalised skein relations that encode the representation theory of a quantum group. In the second half of the paper, we explore the dictionary between topological defect networks and supersymmetric loop operators in the N=2{sup ∗} theory by comparing to exact localisation computations. In this context, the the generalised skein relations are related to the operator product expansion of loop operators.

On the duality-transformed Wilson loop operator

International Nuclear Information System (INIS)

Mizrachi, L.

1981-08-01

Duality transformation of the vacuum expectation value of the Wilson loop operator is performed in the radial gauge (xsub(μ)Asub(μ)sup(a)(x) = 0). It is found to be equal, up to a multiplicative constant, to , where O(c) is a line integral along the loop c (defining the Wilson loop operator) of a function of the dual field variables. In the weak coupling region self duality is recovered in the sense that the Lagrangian is local gauge invariant defined in terms of the dual gauge potentials but with g (the coupling constant) replaced by 1/g, and O(c) is simply the line integral of the dual gauge potentials. For large g, a strong coupling expansion is suggested (but the theory is not local gauge invariant). (author)

Exact results for ABJ Wilson loops and open-closed duality

Energy Technology Data Exchange (ETDEWEB)

Hatsuda, Yasuyuki [Département de Physique Théorique et section de Mathématiques, Université de Genève,Genève, CH-1211 (Switzerland); Okuyama, Kazumi [Department of Physics, Shinshu University,Matsumoto 390-8621 (Japan)

2016-10-24

We find new exact relations between the partition function and vacuum expectation values (VEVs) of 1/2 BPS Wilson loops in ABJ theory, which allow us to predict the large N expansions of the 1/2 BPS Wilson loops from known results of the partition function. These relations are interpreted as an open-closed duality where the closed string background is shifted by the insertion of Wilson loops due to a back-reaction. Using the connection between ABJ theory and the topological string on local ℙ{sup 1}×ℙ{sup 1}, we explicitly write down non-trivial relations between open and closed string amplitudes.

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.

Wilson loops in Kerr gravitation

International Nuclear Information System (INIS)

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

1981-01-01

The ordered integrals for several paths in Kerr gravitation is computed in a compact form. When the path is closed its relation with the angular parallel displacement is discussed and the corresponding Wilson loop is calculated. The validity of Mandelstam relations for gauge fields is also explicitly verified. (Author) [pt

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.

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

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.)

Exact results for Wilson loops in arbitrary representations

Energy Technology Data Exchange (ETDEWEB)

Fiol, Bartomeu; Torrents, Genís [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona,Martí i Franquès 1, 08028 Barcelona, Catalonia (Spain)

2014-01-08

We compute the exact vacuum expectation value of 1/2 BPS circular Wilson loops of N=4 U(N) super Yang-Mills in arbitrary irreducible representations. By localization arguments, the computation reduces to evaluating certain integrals in a Gaussian matrix model, which we do using the method of orthogonal polynomials. Our results are particularly simple for Wilson loops in antisymmetric representations; in this case, we observe that the final answers admit an expansion where the coefficients are positive integers, and can be written in terms of sums over skew Young diagrams. As an application of our results, we use them to discuss the exact Bremsstrahlung functions associated to the corresponding heavy probes.

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.)

Supersymmetric Regularization Two-Loop QCD Amplitudes and Coupling Shifts

Energy Technology Data Exchange (ETDEWEB)

Dixon, Lance

2002-03-08

We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It amounts to a variation on the standard 't Hooft-Veltman scheme and is designed to be compatible with the use of helicity states for ''observed'' particles. It is similar to dimensional reduction in that it maintains an equal number of bosonic and fermionic states, as required for preserving supersymmetry. Supersymmetry Ward identities relate different helicity amplitudes in supersymmetric theories. As a check that the FDH scheme preserves supersymmetry, at least through two loops, we explicitly verify a number of these identities for gluon-gluon scattering (gg {yields} gg) in supersymmetric QCD. These results also cross-check recent non-trivial two-loop calculations in ordinary QCD. Finally, we compute the two-loop shift between the FDH coupling and the standard {bar M}{bar S} coupling, {alpha}{sub s}. The FDH shift is identical to the one for dimensional reduction. The two-loop coupling shifts are then used to obtain the three-loop QCD {beta} function in the FDH and dimensional reduction schemes.

Supersymmetric Regularization Two-Loop QCD Amplitudes and Coupling Shifts

International Nuclear Information System (INIS)

Dixon, Lance

2002-01-01

We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It amounts to a variation on the standard 't Hooft-Veltman scheme and is designed to be compatible with the use of helicity states for ''observed'' particles. It is similar to dimensional reduction in that it maintains an equal number of bosonic and fermionic states, as required for preserving supersymmetry. Supersymmetry Ward identities relate different helicity amplitudes in supersymmetric theories. As a check that the FDH scheme preserves supersymmetry, at least through two loops, we explicitly verify a number of these identities for gluon-gluon scattering (gg → gg) in supersymmetric QCD. These results also cross-check recent non-trivial two-loop calculations in ordinary QCD. Finally, we compute the two-loop shift between the FDH coupling and the standard MS coupling, α s . The FDH shift is identical to the one for dimensional reduction. The two-loop coupling shifts are then used to obtain the three-loop QCD β function in the FDH and dimensional reduction schemes

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.

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.

Two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories

Directory of Open Access Journals (Sweden)

Junji Hisano

2017-09-01

Full Text Available We derive two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories using the effective Kähler potential. We introduce the general forms in generic gauge theories and apply our results to the flavor-changing operators in (minimal supersymmetric standard models.

Non-supersymmetric loop amplitudes and MHV vertices

International Nuclear Information System (INIS)

Bedford, James; Brandhuber, Andreas; Spence, Bill; Travaglini, Gabriele

2005-01-01

We show how the MHV diagram description of Yang-Mills theories can be used to study non-supersymmetric loop amplitudes. In particular, we derive a compact expression for the cut-constructible part of the general one-loop MHV multi-gluon scattering amplitude in pure Yang-Mills theory. We show that in special cases this expression reduces to known amplitudes-the amplitude with adjacent negative-helicity gluons, and the five gluon non-adjacent amplitude. Finally, we briefly discuss the twistor space interpretation of our result

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

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.

New dualities of supersymmetric gauge theories

CERN Document Server

2016-01-01

This book reviews a number of spectacular advances that have been made in the study of supersymmetric quantum field theories in the last few years. Highlights include exact calculations of Wilson loop expectation values, and highly nontrivial quantitative checks of the long-standing electric-magnetic duality conjectures. The book starts with an introductory article presenting a survey of recent advances, aimed at a wide audience with a background and interest in theoretical physics. The following articles are written for advanced students and researchers in quantum field theory, string theory and mathematical physics, our goal being to familiarize these readers with the forefront of current research. The topics covered include recent advances in the classification and vacuum structure of large families of N=2 supersymmetric field theories, followed by an extensive discussion of the localisation method, one of the most powerful tools for exact studies of supersymmetric field theories. The quantities that have ...

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)

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}).

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

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.)

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

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

Four-loop divergences of the two-dimensional (1,1) supersymmetric non-linear sigma model with a Wess-Zumino-Witten term

International Nuclear Information System (INIS)

Deriglazov, A.A.; Ketov, S.V.

1991-01-01

The four-loop divergences of the (1,1) supersymmetric two-dimensional non-linear σ-model with a Wess-Zumino-Witten term are analyzed. All the four-loop 1/ε-divergences in the general case (and an overall coefficient at the total four-loop contribution to the β-function) are shown to be reducible to only structures proportional to ζ(3). We explicitly calculate non-derivative contributions to the four-loop β-function from logarithmically divergent graphs. As a by-product, we obtain the complete four-loop β-function for the supersymmetric Wess-Zumino-Witten model. We use the partial results for the general four-loop β-function to shed some light on the structure of the (α') 3 -corrections to the superstring effective-action with antisymmetric-tensor field coupling. An inconsistency of the supersymmetrical dimensional regularisation via dimensional reduction in the presence of torsion is discovered at four loops, unless the string interpretation for the σ-model is adopted. (orig.)

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

New two-loop contribution to electric dipole moment in supersymmetric theories

CERN Document Server

Chang, Darwin; Pilaftsis, Apostolos; Chang, Darwin; Keung, Wai-Yee; Pilaftsis, Apostolos

1999-01-01

We calculate a new type of two-loop contributions to the electric dipole moments of the electron and neutron in supersymmetric theories. The new contributions are originated from the potential CP violation in the trilinear couplings of the Higgs bosons to the scalar-top or the scalar-bottom quarks. These couplings were previously very weakly constrained. The electric dipole moments are induced through a mechanism analogous to that due to Barr and Zee. We find observable effects for a sizeable portion of the parameter space related to the third generation scalar-quarks in the minimal supersymmetric standard model which cannot be excluded by earlier considerations.

Renormalization of Supersymmetric QCD on the Lattice

Science.gov (United States)

Costa, Marios; Panagopoulos, Haralambos

2018-03-01

We perform a pilot study of the perturbative renormalization of a Supersymmetric gauge theory with matter fields on the lattice. As a specific example, we consider Supersymmetric N=1 QCD (SQCD). We study the self-energies of all particles which appear in this theory, as well as the renormalization of the coupling constant. To this end we compute, perturbatively to one-loop, the relevant two-point and three-point Green's functions using both dimensional and lattice regularizations. Our lattice formulation involves theWilson discretization for the gluino and quark fields; for gluons we employ the Wilson gauge action; for scalar fields (squarks) we use naive discretization. The gauge group that we consider is SU(Nc), while the number of colors, Nc, the number of flavors, Nf, and the gauge parameter, α, are left unspecified. We obtain analytic expressions for the renormalization factors of the coupling constant (Zg) and of the quark (ZΨ), gluon (Zu), gluino (Zλ), squark (ZA±), and ghost (Zc) fields on the lattice. We also compute the critical values of the gluino, quark and squark masses. Finally, we address the mixing which occurs among squark degrees of freedom beyond tree level: we calculate the corresponding mixing matrix which is necessary in order to disentangle the components of the squark field via an additional finite renormalization.

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.

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.)

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

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.

N = 1 SU(2) supersymmetric Yang-Mills theory on the lattice with light dynamical Wilson gluinos

International Nuclear Information System (INIS)

Demmouche, Kamel

2009-01-01

The supersymmetric Yang-Mills (SYM) theory with one supercharge (N=1) and one additional Majorana matter-field represents the simplest model of supersymmetric gauge theory. Similarly to QCD, this model includes gauge fields, gluons, with color gauge group SU(N c ) and fermion fields, describing the gluinos. The non-perturbative dynamical features of strongly coupled supersymmetric theories are of great physical interest. For this reason, many efforts are dedicated to their formulation on the lattice. The lattice regularization provides a powerful tool to investigate non-perturbatively the phenomena occurring in SYM such as confinement and chiral symmetry breaking. In this work we perform numerical simulations of the pure SU(2) SYM theory on large lattices with small Majorana gluino masses down to about m g approx 115 MeV with lattice spacing up to a ≅0.1 fm. The gluino dynamics is simulated by the Two-Step Multi-Boson (TSMB) and the Two-Step Polynomial Hybrid Monte Carlo (TS-PHMC) algorithms. Supersymmetry (SUSY) is broken explicitly by the lattice and the Wilson term and softly by the presence of a non-vanishing gluino mass m g ≠0. However, the recovery of SUSY is expected in the infinite volume continuum limit by tuning the bare parameters to the SUSY point in the parameter space. This scenario is studied by the determination of the low-energy mass spectrum and by means of lattice SUSY Ward-Identities (WIs). (orig.)

One-loop adjoint masses for non-supersymmetric intersecting branes

Energy Technology Data Exchange (ETDEWEB)

Anastasopoulos, P. [Technische Univ., Vienna (Austria). 1. Inst. fuer Theoretische Physik; Antoniadis, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Benakli, K. [CNRS, UPMC Univ. Paris (France). Lab. de Physique Theorique et Haute Energies; Goodsell, M.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vichi, A. [Institute de Theorie des Phenomenes Physiques, EPFL, Lausanne (Switzerland)

2011-05-15

We consider breaking of supersymmetry in intersecting D-brane configurations by slight deviation of the angles from their supersymmetric values. We compute the masses generated by radiative corrections for the adjoint scalars on the brane world-volumes. In the open string channel, the string two-point function receives contributions only from the infrared and the ultraviolet limits. The latter is due to tree-level closed string uncanceled NS-NS tadpoles, which we explicitly reproduce from the effective Born-Infeld action. On the other hand, the infrared region reproduces the one-loop mediation of supersymmetry breaking in the effective gauge theory, via messengers and their Kaluza-Klein excitations. In the toroidal set-up considered here, it receives contributions only from N {approx} 4 and N {approx} 2 supersymmetric configurations, and thus always leads at leading order to a tachyonic direction, in agreement with effective field theory expectations. (orig.)

Summation of all-loop UV divergences in maximally supersymmetric gauge theories

International Nuclear Information System (INIS)

Borlakov, A.T.; Kazakov, D.I.; Tolkachev, D.M.; Vlasenko, D.E.

2016-01-01

We consider the leading and subleading UV divergences for the four-point on-shell scattering amplitudes in D=6,8,10 supersymmetric Yang-Mills theories in the planar limit. These theories belong to the class of maximally supersymmetric gauge theories and presumably possess distinguished properties beyond perturbation theory. In the previous works, we obtained the recursive relations that allow one to get the leading and subleading divergences in all loops in a pure algebraic way. The all loop summation of the leading divergences is performed with the help of the differential equations which are the generalization of the RG equations for non-renormalizable theories. Here we mainly focus on solving and analyzing these equations. We discuss the properties of the obtained solutions and interpretation of the results. The key issue is that the summation of infinite series for the leading and the subleading divergences does improve the situation and does not allow one to remove the regularization and obtain the finite answer. This means that despite numerous cancellations of divergent diagrams these theories remain non-renormalizable.

Summation of all-loop UV divergences in maximally supersymmetric gauge theories

Energy Technology Data Exchange (ETDEWEB)

Borlakov, A.T. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research,Dubna (Russian Federation); Moscow Institute of Physics and Technology,Dolgoprudny (Russian Federation); Kazakov, D.I. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research,Dubna (Russian Federation); Alikhanov Institute for Theoretical and Experimental Physics,Moscow (Russian Federation); Moscow Institute of Physics and Technology,Dolgoprudny (Russian Federation); Tolkachev, D.M. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research,Dubna (Russian Federation); Stepanov Institute of Physics,Minsk (Belarus); Vlasenko, D.E. [Department of Physics, South Federal State University,Rostov-Don (Russian Federation)

2016-12-29

We consider the leading and subleading UV divergences for the four-point on-shell scattering amplitudes in D=6,8,10 supersymmetric Yang-Mills theories in the planar limit. These theories belong to the class of maximally supersymmetric gauge theories and presumably possess distinguished properties beyond perturbation theory. In the previous works, we obtained the recursive relations that allow one to get the leading and subleading divergences in all loops in a pure algebraic way. The all loop summation of the leading divergences is performed with the help of the differential equations which are the generalization of the RG equations for non-renormalizable theories. Here we mainly focus on solving and analyzing these equations. We discuss the properties of the obtained solutions and interpretation of the results. The key issue is that the summation of infinite series for the leading and the subleading divergences does improve the situation and does not allow one to remove the regularization and obtain the finite answer. This means that despite numerous cancellations of divergent diagrams these theories remain non-renormalizable.

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

Two loop effective Kahler potential of (non)-renormalizable supersymmetric models

International Nuclear Information System (INIS)

Groot Nibbelink, S.; Nyawelo, T.S.

2005-10-01

We perform a supergraph computation of the effective Kahler potential at one and two loops for general four dimensional N=1 supersymmetric theories described by arbitrary Kahler potential, superpotential and gauge kinetic function. We only insist on gauge invariance of the Kahler potential and the superpotential as we heavily rely on its consequences in the quantum theory. However, we do not require gauge invariance for the gauge kinetic functions, so that our results can also be applied to anomalous theories that involve the Green-Schwarz mechanism. We illustrate our two loop results by considering a few simple models: the (non-)renormalizable Wess-Zumino model and Super Quantum Electrodynamics. (author)

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 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.

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

Iteration of planar amplitudes in maximally supersymmetric Yang-Mills theory at three loops and beyond

International Nuclear Information System (INIS)

Bern, Zvi; Dixon, Lance J.; Smirnov, Vladimir A.

2005-01-01

We compute the leading-color (planar) three-loop four-point amplitude of N=4 supersymmetric Yang-Mills theory in 4-2ε dimensions, as a Laurent expansion about ε=0 including the finite terms. The amplitude was constructed previously via the unitarity method, in terms of two Feynman loop integrals, one of which has been evaluated already. Here we use the Mellin-Barnes integration technique to evaluate the Laurent expansion of the second integral. Strikingly, the amplitude is expressible, through the finite terms, in terms of the corresponding one- and two-loop amplitudes, which provides strong evidence for a previous conjecture that higher-loop planar N=4 amplitudes have an iterative structure. The infrared singularities of the amplitude agree with the predictions of Sterman and Tejeda-Yeomans based on resummation. Based on the four-point result and the exponentiation of infrared singularities, we give an exponentiated Ansatz for the maximally helicity-violating n-point amplitudes to all loop orders. The 1/ε 2 pole in the four-point amplitude determines the soft, or cusp, anomalous dimension at three loops in N=4 supersymmetric Yang-Mills theory. The result confirms a prediction by Kotikov, Lipatov, Onishchenko and Velizhanin, which utilizes the leading-twist anomalous dimensions in QCD computed by Moch, Vermaseren and Vogt. Following similar logic, we are able to predict a term in the three-loop quark and gluon form factors in QCD

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

Supersymmetric and non-supersymmetric models without catastrophic Goldstone bosons

Energy Technology Data Exchange (ETDEWEB)

Braathen, Johannes; Goodsell, Mark D. [LPTHE, UPMC Univ. Paris 6, Sorbonne Universites, Paris (France); LPTHE, CNRS, Paris (France); Staub, Florian [Karlsruhe Institute of Technology, Institute for Theoretical Physics (ITP), Karlsruhe (Germany); Karlsruhe Institute of Technology, Institute for Nuclear Physics (IKP), Eggenstein-Leopoldshafen (Germany)

2017-11-15

The calculation of the Higgs mass in general renormalisable field theories has been plagued by the so-called ''Goldstone Boson Catastrophe'', where light (would-be) Goldstone bosons give infra-red divergent loop integrals. In supersymmetric models, previous approaches included a workaround that ameliorated the problem for most, but not all, parameter space regions; while giving divergent results everywhere for non-supersymmetric models. We present an implementation of a general solution to the problem in the public code SARAH, along with new calculations of some necessary loop integrals and generic expressions. We discuss the validation of our code in the Standard Model, where we find remarkable agreement with the known results. We then show new applications in Split SUSY, the NMSSM, the Two-Higgs-Doublet Model, and the Georgi-Machacek model. In particular, we take some first steps to exploring where the habit of using tree-level mass relations in non-supersymmetric models breaks down, and show that the loop corrections usually become very large well before naive perturbativity bounds are reached. (orig.)

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

Zero value for the three-loop β function in N=4 supersymmetric Yang-Mills theory

International Nuclear Information System (INIS)

Grisaru, M.; Rocek, M.; Siegel, W.

1980-01-01

This Letter describes a calculation using superfield techniques, showing that the β function is zero to three loops in N=4 supersymmetric Yang-Mills theory. This result gives further indication that the theory is likely to be finite and conformally invariant order by order in perturbation theory

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.

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

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.

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

Supersymmetric localization for BPS black hole entropy: 1-loop partition function from vector multiplets

International Nuclear Information System (INIS)

Gupta, Rajesh Kumar; Ito, Yuto; Jeon, Imtak

2015-01-01

We use the techniques of supersymmetric localization to compute the BPS black hole entropy in N=2 supergravity. We focus on the n_v+1 vector multiplets on the black hole near horizon background which is AdS_2× S"2 space. We find the localizing saddle point of the vector multiplets by solving the localization equations, and compute the exact one-loop partition function on the saddle point. Furthermore, we propose the appropriate functional integration measure. Through this measure, the one-loop determinant is written in terms of the radius of the physical metric, which depends on the localizing saddle point value of the vector multiplets. The result for the one-loop determinant is consistent with the logarithmic corrections to the BPS black hole entropy from vector multiplets.

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.)

Automatic calculation of supersymmetric renormalization group equations and loop corrections

Science.gov (United States)

Staub, Florian

2011-03-01

SARAH is a Mathematica package for studying supersymmetric models. It calculates for a given model the masses, tadpole equations and all vertices at tree-level. This information can be used by SARAH to write model files for CalcHep/ CompHep or FeynArts/ FormCalc. In addition, the second version of SARAH can derive the renormalization group equations for the gauge couplings, parameters of the superpotential and soft-breaking parameters at one- and two-loop level. Furthermore, it calculates the one-loop self-energies and the one-loop corrections to the tadpoles. SARAH can handle all N=1 SUSY models whose gauge sector is a direct product of SU(N) and U(1) gauge groups. The particle content of the model can be an arbitrary number of chiral superfields transforming as any irreducible representation with respect to the gauge groups. To implement a new model, the user has just to define the gauge sector, the particle, the superpotential and the field rotations to mass eigenstates. Program summaryProgram title: SARAH Catalogue identifier: AEIB_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIB_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 97 577 No. of bytes in distributed program, including test data, etc.: 2 009 769 Distribution format: tar.gz Programming language: Mathematica Computer: All systems that Mathematica is available for Operating system: All systems that Mathematica is available for Classification: 11.1, 11.6 Nature of problem: A supersymmetric model is usually characterized by the particle content, the gauge sector and the superpotential. It is a time consuming process to obtain all necessary information for phenomenological studies from these basic ingredients. Solution method: SARAH calculates the complete Lagrangian for a given model whose

Stochastic quantization of field theories on the lattice and supersymmetrical models

International Nuclear Information System (INIS)

Aldazabal, Gerardo.

1984-01-01

Several aspects of the stochastic quantization method are considered. Specifically, field theories on the lattice and supersymmetrical models are studied. A non-linear sigma model is studied firstly, and it is shown that it is possible to obtain evolution equations written directly for invariant quantities. These ideas are generalized to obtain Langevin equations for the Wilson loops of non-abelian lattice gauge theories U (N) and SU (N). In order to write these equations, some different ways of introducing the constraints which the fields must satisfy are discussed. It is natural to have a strong coupling expansion in these equations. The correspondence with quantum field theory is established, and it is noticed that at all orders in the perturbation theory, Langevin equations reduce to Schwinger-Dyson equations. From another point of view, stochastic quantization is applied to large N matrix models on the lattice. As a result, a simple and systematic way of building reduced models is found. Referring to stochastic quantization in supersymmetric theories, a simple supersymmetric model is studied. It is shown that it is possible to write an evolution equation for the superfield wich leads to quantum field theory results in equilibrium. As the Langevin equation preserves supersymmetry, the property of dimensional reduction known for the quantum model is shown to be valid at all times. (M.E.L.) [es

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

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.

Three-loop renormalization of the N=1, N=2, N=4 supersymmetric Yang-Mills theories

International Nuclear Information System (INIS)

Velizhanin, V.N.

2009-01-01

We calculate the renormalization constants of the N=1, N=2, N=4 supersymmetric Yang-Mills theories in an arbitrary covariant gauge in the dimensional reduction scheme up to three loops. We have found, that the beta-functions for N=1 and N=4 SYM theories are the same from the different triple vertices. This means that the dimensional reduction scheme works correctly in these models up to third order of perturbative theory.

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.

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

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.

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.)

One-loop analysis of the electroweak breaking in supersymmetric models and the fine-tuning problem

CERN Document Server

De Carlos, B

1993-01-01

We examine the electroweak breaking mechanism in the minimal supersymmetric standard model (MSSM) using the {\\em complete} one-loop effective potential $V_1$. First, we study what is the region of the whole MSSM parameter space (i.e. $M_{1/2},m_o,\\mu,...$) that leads to a succesful $SU(2)\\times U(1)$ breaking with an acceptable top quark mass. In doing this it is observed that all the one-loop corrections to $V_1$ (even the apparently small ones) must be taken into account in order to get reliable results. We find that the allowed region of parameters is considerably enhanced with respect to former "improved" tree level results. Next, we study the fine-tuning problem associated with the high sensitivity of $M_Z$ to $h_t$ (the top Yukawa coupling). Again, we find that this fine-tuning is appreciably smaller once the one-loop effects are considered than in previous tree level calculations. Finally, we explore the ambiguities and limitations of the ordinary criterion to estimate the degree of fine-tuning. As a r...

Calabi-Yau compactifications of non-supersymmetric heterotic string theory

International Nuclear Information System (INIS)

Blaszczyk, Michael; Groot Nibbelink, Stefan

2015-07-01

Phenomenological explorations of heterotic strings have conventionally focused primarily on the E 8 x E 8 theory. We consider smooth compactifications of all three ten-dimensional heterotic theories to exhibit the many similarities between the non-supersymmetric SO(16) x SO(16) theory and the related supersymmetric E 8 x E 8 and SO(32) theories. In particular, we exploit these similarities to determine the bosonic and fermionic spectra of Calabi-Yau compactifications with line bundles of the nonsupersymmetric string. We use elements of four-dimensional supersymmetric effective field theory to characterize the non-supersymmetric action at leading order and determine the Green-Schwarz induced axion-couplings. Using these methods we construct a non-supersymmetric Standard Model(SM)-like theory. In addition, we show that it is possible to obtain SM-like models from the standard embedding using at least an order four Wilson line. Finally, we make a proposal of the states that live on five branes in the SO(16) x SO(16) theory and find under certain assumptions the surprising result that anomaly factorization only admits at most a single brane solution.

The supersymmetric Adler-Bardeen theorem and regularization by dimensional reduction

International Nuclear Information System (INIS)

Ensign, P.; Mahanthappa, K.T.

1987-01-01

We examine the subtraction scheme dependence of the anomaly of the supersymmetric, gauge singlet axial current in pure and coupled supersymmetric Yang-Mills theories. Preserving supersymmetry and gauge invariance explicitly by using supersymmetric background field theory and dimensional reduction, we show that only the one-loop value of the axial anomaly is subtraction scheme independent, and that one can always define a subtraction scheme in which the Adler-Bardeen theorem is satisfied to all orders in perturbation theory. In general this subtraction scheme may be non-minimal, but in both the pure and the coupled theories, the Adler-Bardeen theorem is satisfied to two loops in minimal subtraction. (orig.)

Supercurrent and the Adler-Bardeen theorem in coupled supersymmetric Yang-Mills theories

International Nuclear Information System (INIS)

Ensign, P.; Mahanthappa, K.T.

1987-01-01

We construct the supercurrent and a supersymmetric current which satisfies the Adler-Bardeen theorem in supersymmetric Yang-Mills theory coupled to non-self-interacting chiral matter. Using the formulation recently developed by Grisaru, Milewski, and Zanon, supersymmetry and gauge invariance are maintained with supersymmetric background-field theory and regularization by dimensional reduction. We verify the finiteness of the supercurrent to one loop, and the Adler-Bardeen theorem to two loops by explicit calculations in the minimal-subtraction scheme. We then demonstrate the subtraction-scheme independence of the one-loop Adler-Bardeen anomaly and prove the existence of a subtraction scheme in which the Adler-Bardeen theorem is satisfied to all orders in perturbation theory

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.)

Localization of supersymmetric field theories on non-compact hyperbolic three-manifolds

Energy Technology Data Exchange (ETDEWEB)

Assel, Benjamin; Martelli, Dario; Murthy, Sameer; Yokoyama, Daisuke [Department of Mathematics, King’s College London,The Strand, London WC2R 2LS (United Kingdom)

2017-03-17

We study supersymmetric gauge theories with an R-symmetry, defined on non-compact, hyperbolic, Riemannian three-manifolds, focusing on the case of a supersymmetry-preserving quotient of Euclidean AdS{sub 3}. We compute the exact partition function in these theories, using the method of localization, thus reducing the problem to the computation of one-loop determinants around a supersymmetric locus. We evaluate the one-loop determinants employing three different techniques: an index theorem, the method of pairing of eigenvalues, and the heat kernel method. Along the way, we discuss aspects of supersymmetry in manifolds with a conformal boundary, including supersymmetric actions and boundary conditions.

Two-loop renormalization group analysis of supersymmetric SO(10) models with an intermediate scale

International Nuclear Information System (INIS)

Bastero-Gil, M.; Brahmachari, B.

1996-03-01

Two-loop evolutions of the gauge couplings in a class of intermediate scale supersymmetric SO(10) models including the effect of third generation Yukawa couplings are studied. The unification scale, the intermediate scale and the value of the unification gauge coupling in these models are calculated and the gauge boson mediated proton decay rates are estimated. In some cases the predicted proton lifetime turns out to be in the border-line of experimental limit. The predictions of the top quark mass, the mass ratio m b (m b )/m τ (m τ ) from the two-loop evolution of Yukawa couplings and the mass of the left handed neutrino via see-saw mechanism are summarized. The lower bounds on the ratio of the VEVs of the two low energy doublets (tan β) from the requirement of the perturbative unitarity of the top quark Yukawa coupling up to the grand unification scale are also presented. All the predictions have been compared with those of the one-step unified theory. (author). 33 refs, 5 figs, 1 tab

Supercurrent and the Adler-Bardeen theorem in coupled supersymmetric Yang-Mills theories

International Nuclear Information System (INIS)

Ensign, P.W.

1987-01-01

By the Adler-Bardeen theorem, only one-loop Feynman diagrams contribute to the anomalous divergences of quantum axial currents. The anomalous nature of scale transformations is manifested by an anomalous trace of the energy-momentum tensor, T/sup μ//sub μ/. Renormalization group arguments show that the quantum T/sup μ//sub μ/ must be proportional to the β-function. Since the β-function receives contributions at all loop levels, the Adler-Bardeen theorem appears to conflict with supersymmetry. Recently Grisaru, Milewski and Zanon constructed a supersymmetric axial current for pure supersymmetric Yang-Mills theory which satisfies the Adler-Bardeen theorem to two-loops. They used supersymmetric background field theory and regularization by dimensional reduction to maintain manifest supersymmetry and gauge invariance. In this thesis, their construction is extended to supersymmetric Yang-Mills theory coupled to chiral matter fields. The Adler-Bardeen theorem is then proven to all orders in perturbation theory for both the pure and coupled theories. The extension to coupled supersymmetric Yang-Mills supports the general validity of these techniques, and adds considerable insight into the structure of the anomalies. The all orders proof demonstrates that there is no conflict between supersymmetry and the Adler-Bardeen theorem

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

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.

Consistent momentum space regularization/renormalization of supersymmetric quantum field theories: the three-loop β-function for the Wess-Zumino model

International Nuclear Information System (INIS)

Carneiro, David; Sampaio, Marcos; Nemes, Maria Carolina; Scarpelli, Antonio Paulo Baeta

2003-01-01

We compute the three loop β function of the Wess-Zumino model to motivate implicit regularization (IR) as a consistent and practical momentum-space framework to study supersymmetric quantum field theories. In this framework which works essentially in the physical dimension of the theory we show that ultraviolet are clearly disentangled from infrared divergences. We obtain consistent results which motivate the method as a good choice to study supersymmetry anomalies in quantum field theories. (author)

Superfield approach to calculation of effective potential in supersymmetric field theories

International Nuclear Information System (INIS)

Bukhbinder, I.L.; Kuzenko, S.M.; Yarevskaya, Zh.V.

1993-01-01

Superfield method of computing effective potential in supersymmetric field theories is suggested. The one-loop effective potential of the Wess-Zumino model is found. The prescription for obtaining multi-loop corrections is described

Supersymmetric extension of the Adler-Bardeen theorem

International Nuclear Information System (INIS)

Novikov, V.A.; Zakharov, V.I.; Shifman, M.A.; Vainshtein, A.I.

1985-01-01

A supersymmetric generalization of the Adler-Bardeen theorem in SUSY gauge theories is given. We show that within the Adler-Bardeen procedure, both the conformal and axial anomalies are exhausted by one loop. (orig.)

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.

Vacuum fluctuations of the supersymmetric field in curved background

International Nuclear Information System (INIS)

Bilić, Neven; Domazet, Silvije; Guberina, Branko

2012-01-01

We study a supersymmetric model in curved background spacetime. We calculate the effective action and the vacuum expectation value of the energy momentum tensor using a covariant regularization procedure. A soft supersymmetry breaking induces a nonzero contribution to the vacuum energy density and pressure. Assuming the presence of a cosmic fluid in addition to the vacuum fluctuations of the supersymmetric field an effective equation of state is derived in a self-consistent approach at one loop order. The net effect of the vacuum fluctuations of the supersymmetric fields in the leading adiabatic order is a renormalization of the Newton and cosmological constants.

Vacuum fluctuations of the supersymmetric field in curved background

Energy Technology Data Exchange (ETDEWEB)

Bilic, Neven, E-mail: bilic@thphys.irb.hr [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia); Domazet, Silvije, E-mail: sdomazet@irb.hr [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia); Guberina, Branko, E-mail: guberina@thphys.irb.hr [Rudjer Boskovic Institute, POB 180, HR-10002 Zagreb (Croatia)

2012-01-16

We study a supersymmetric model in curved background spacetime. We calculate the effective action and the vacuum expectation value of the energy momentum tensor using a covariant regularization procedure. A soft supersymmetry breaking induces a nonzero contribution to the vacuum energy density and pressure. Assuming the presence of a cosmic fluid in addition to the vacuum fluctuations of the supersymmetric field an effective equation of state is derived in a self-consistent approach at one loop order. The net effect of the vacuum fluctuations of the supersymmetric fields in the leading adiabatic order is a renormalization of the Newton and cosmological constants.

An object oriented code for simulating supersymmetric Yang-Mills theories

Science.gov (United States)

Catterall, Simon; Joseph, Anosh

2012-06-01

, including test data, etc.: 95 371 Distribution format: tar.gz Programming language: C++ Computer: PCs and Workstations Operating system: Any, tested on Linux machines Classification:: 11.6 Nature of problem: To compute some of the observables of supersymmetric Yang-Mills theories such as supersymmetric action, Polyakov/Wilson loops, scalar eigenvalues and Pfaffian phases. Solution method: We use the Rational Hybrid Monte Carlo algorithm followed by a Leapfrog evolution and a Metropolis test. The input parameters of the model are read in from a parameter file. Restrictions: This code applies only to supersymmetric gauge theories with extended supersymmetry, which undergo the process of maximal twisting. (See Section 2 of the manuscript for details.) Running time: From a few minutes to several hours depending on the amount of statistics needed.

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.

Ultraviolet divergences in higher dimensional supersymmetric Yang-Mills theories

International Nuclear Information System (INIS)

Howe, P.S.; Stelle, K.S.

1984-01-01

We determine the loop orders for the onset of allowed ultra-violet divergences in higher dimensional supersymmetric Yang-Mills theories. Cancellations are controlled by the non-renormalization theorems for the linearly realizable supersymmetries and by the requirement that counterterms display the full non-linear supersymmetries when the classical equations of motion are imposed. The first allowed divergences in the maximal super Yang-Mills theories occur at four loops in five dimensions, three loops in six dimensions and two loops in seven dimensions. (orig.)

The massless supersymmetric ladder with L rungs

International Nuclear Information System (INIS)

Rossi, G.C.; Stanev, Ya.S.

2009-01-01

We show that in the massless N=1 supersymmetric Wess-Zumino theory it is possible to devise a computational strategy by which the x-space calculation of the ladder 4-point correlators can be carried out without introducing any regularization. As an application we derive a representation valid at all loop orders in terms of conformal invariant integrals. We obtain an explicit expression of the 3-loop ladder diagram for collinear external points

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.)

(Non-)decoupled supersymmetric field theories

International Nuclear Information System (INIS)

Pietro, Lorenzo Di; Dine, Michael; Komargodski, Zohar

2014-01-01

We study some consequences of coupling supersymmetric theories to (super)gravity. To linear order, the couplings are determined by the energy-momentum supermultiplet. At higher orders, the couplings are determined by contact terms in correlation functions of the energy-momentum supermultiplet. We focus on the couplings of one particular field in the supergravity multiplet, the auxiliary field M. We discuss its linear and quadratic (seagull) couplings in various supersymmetric theories. In analogy to the local renormalization group formalism (http://dx.doi.org/10.1016/0370-2693(89)90729-6; http://dx.doi.org/10.1016/0550-3213(90)90584-Z; http://dx.doi.org/10.1016/0550-3213(91)80030-P), we provide a prescription for how to fix the quadratic couplings. They generally arise at two-loops in perturbation theory. We check our prescription by explicitly computing these couplings in several examples such as mass-deformed N=4 and in the Coulomb phase of some theories. These couplings affect the Lagrangians of rigid supersymmetric theories in curved space. In addition, our analysis leads to a transparent derivation of the phenomenon known as Anomaly Mediation. In contrast to previous approaches, we obtain both the gaugino and scalar masses of Anomaly Mediation by relying just on classical, minimal supergravity and a manifestly local and supersymmetric Wilsonian point of view. Our discussion naturally incorporates the connection between Anomaly Mediation and supersymmetric AdS 4 Lagrangians. This note can be read without prior familiarity with Anomaly Mediated Supersymmetry Breaking (AMSB)

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 Four-Loop Planar Amplitude and Cusp Anomalous Dimension in Maximally Supersymmetric Yang-Mills Theory

International Nuclear Information System (INIS)

Bern, Zvi; Czakon, Michael; Dixon, Lance J.; Kosower, David A.; Smirnov, Vladimir A.

2006-01-01

We present an expression for the leading-color (planar) four-loop four-point amplitude of N = 4 supersymmetric Yang-Mills theory in 4-2ε dimensions, in terms of eight separate integrals. The expression is based on consistency of unitarity cuts and infrared divergences. We expand the integrals around ε = 0, and obtain analytic expressions for the poles from 1/ε 8 through 1/ε 4 . We give numerical results for the coefficients of the 1/ε 3 and 1/e 2 poles. These results all match the known exponentiated structure of the infrared divergences, at four separate kinematic points. The value of the 1/ε 2 coefficient allows us to test a conjecture of Eden and Staudacher for the four-loop cusp (soft) anomalous dimension. We find that the conjecture is incorrect, although our numerical results suggest that a simple modification of the expression, flipping the sign of the term containing ζ 3 2 , may yield the correct answer. Our numerical value can be used, in a scheme proposed by Kotikov, Lipatov and Velizhanin, to estimate the two constants in the strong-coupling expansion of the cusp anomalous dimension that are known from string theory. The estimate works to 2.6% and 5% accuracy, providing non-trivial evidence in support of the AdS/CFT correspondence. We also use the known constants in the strong-coupling expansion as additional input to provide approximations to the cusp anomalous dimension which should be accurate to under one percent for all values of the coupling. When the evaluations of the integrals are completed through the finite terms, it will be possible to test the iterative, exponentiated structure of the finite terms in the four-loop four-point amplitude, which was uncovered earlier at two and three loops

Supersymmetric SO(10) models inspired by deconstruction

International Nuclear Information System (INIS)

Huang Chaoshang; Jiang Jing; Li Tianjun

2004-01-01

We consider 4-dimensional N=1 supersymmetric SO(10) models inspired by deconstruction of 5-dimensional N=1 supersymmetric orbifold SO(10) models and high-dimensional non-supersymmetric SO(10) models with Wilson line gauge symmetry breaking. We discuss the SO(10)xSO(10) models with bi-fundamental link fields where the gauge symmetry can be broken down to the Pati-Salam, SU(5)xU(1), flipped SU(5)xU(1)' or the Standard Model like gauge symmetry. We also propose an SO(10)xSO(6)xSO(4) model with bi-fundamental link fields where the gauge symmetry is broken down to the Pati-Salam gauge symmetry, and an SO(10)xSO(10) model with bi-spinor link fields where the gauge symmetry is broken down to the flipped SU(5)xU(1)' gauge symmetry. In these two models, the Pati-Salam and flipped SU(5)xU(1)' gauge symmetry can be further broken down to the Standard Model gauge symmetry, the doublet-triplet splittings can be obtained by the missing partner mechanism, and the proton decay problem can be solved. We also study the gauge coupling unification. We briefly comment on the interesting variation models with gauge groups SO(10)xSO(6) and SO(10)xflippedSU(5)xU(1)' in which the proton decay problem can be solved

The rho-parameter in supersymmetric models

International Nuclear Information System (INIS)

Lim, C.S.; Inami, T.; Sakai, N.

1983-10-01

The electroweak rho-parameter is examined in a general class of supersymmetric models. Formulae are given for one-loop contributions to Δrho from scalar quarks and leptons, gauge-Higgs fermions and an extra doublet of Higgs scalars. Mass differences between members of isodoublet scalar quarks and leptons are constrained to be less than about 200 GeV. (author)

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.

(Non-)decoupled supersymmetric field theories

Energy Technology Data Exchange (ETDEWEB)

Pietro, Lorenzo Di [Department of Particle Physics and Astrophysics,Weizmann Institute of Science, Rehovot 76100 (Israel); Dine, Michael [Santa Cruz Institute for Particle Physics and Department of Physics,Santa Cruz CA 95064 (United States); Komargodski, Zohar [Department of Particle Physics and Astrophysics,Weizmann Institute of Science, Rehovot 76100 (Israel)

2014-04-10

We study some consequences of coupling supersymmetric theories to (super)gravity. To linear order, the couplings are determined by the energy-momentum supermultiplet. At higher orders, the couplings are determined by contact terms in correlation functions of the energy-momentum supermultiplet. We focus on the couplings of one particular field in the supergravity multiplet, the auxiliary field M. We discuss its linear and quadratic (seagull) couplings in various supersymmetric theories. In analogy to the local renormalization group formalism (http://dx.doi.org/10.1016/0370-2693(89)90729-6; http://dx.doi.org/10.1016/0550-3213(90)90584-Z; http://dx.doi.org/10.1016/0550-3213(91)80030-P), we provide a prescription for how to fix the quadratic couplings. They generally arise at two-loops in perturbation theory. We check our prescription by explicitly computing these couplings in several examples such as mass-deformed N=4 and in the Coulomb phase of some theories. These couplings affect the Lagrangians of rigid supersymmetric theories in curved space. In addition, our analysis leads to a transparent derivation of the phenomenon known as Anomaly Mediation. In contrast to previous approaches, we obtain both the gaugino and scalar masses of Anomaly Mediation by relying just on classical, minimal supergravity and a manifestly local and supersymmetric Wilsonian point of view. Our discussion naturally incorporates the connection between Anomaly Mediation and supersymmetric AdS{sub 4} Lagrangians. This note can be read without prior familiarity with Anomaly Mediated Supersymmetry Breaking (AMSB)

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)

Precision holography for N={2}^{\\ast } on S 4 from type IIB supergravity

Science.gov (United States)

Bobev, Nikolay; Gautason, Friðrik Freyr; van Muiden, Jesse

2018-04-01

We find a new supersymmetric solution of type IIB supergravity which is holographically dual to the planar limit of the four-dimensional N={2}^{\\ast } supersymmetric Yang-Mills theory on S 4. We study a probe fundamental string in this background which is dual to a supersymmetric Wilson loop in the N={2}^{\\ast } theory. Using holography we calculate the expectation value of this line operator to leading order in the 't Hooft coupling. The result is a non-trivial function of the mass parameter of the N={2}^{\\ast } theory that precisely matches the result from supersymmetric localization.

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...

Singularity Structure of Maximally Supersymmetric Scattering Amplitudes

DEFF Research Database (Denmark)

Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy

2014-01-01

We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....

Supersymmetric hybrid inflation with non-minimal Kahler potential

International Nuclear Information System (INIS)

Bastero-Gil, M.; King, S.F.; Shafi, Q.

2007-01-01

Minimal supersymmetric hybrid inflation based on a minimal Kahler potential predicts a spectral index n s ∼>0.98. On the other hand, WMAP three year data prefers a central value n s ∼0.95. We propose a class of supersymmetric hybrid inflation models based on the same minimal superpotential but with a non-minimal Kahler potential. Including radiative corrections using the one-loop effective potential, we show that the prediction for the spectral index is sensitive to the small non-minimal corrections, and can lead to a significantly red-tilted spectrum, in agreement with WMAP

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.

The electric dipole moment of the neutron in the left-right supersymmetric model

International Nuclear Information System (INIS)

Frank, M.

1999-01-01

We calculate the neutron electric dipole moment (EDM) in the left-right supersymmetric model, including one-loop contributions from the chargino, the neutralino and the gluino diagrams. We discuss the dependence of the EDM on the phases of the model, as well as on the mass parameters in the left and right sectors. The neutron EDM imposes different conditions on the supersymmetric spectrum from either the electron EDM, or the neutron EDM in the minimal supersymmetric standard model. The neutron EDM may be a clue to an extended gauge structure in supersymmetry. (author)

Effective Lagrangian for the χi+χj0H- interaction in the minimal supersymmetric standard model and charged Higgs decays

International Nuclear Information System (INIS)

Ibrahim, Tarek; Nath, Pran; Psinas, Anastasios

2004-01-01

We extend previous analyses of the supersymmetric loop correction to the charged Higgs couplings to include the coupling H ± χ ± χ 0 . The analysis completes the previous analyses where similar corrections were computed for H + t-barb (H - tb-bar), and for H + τ - ν-bar τ (H - τ + ν τ ) couplings within the minimal supersymmetric standard model. The effective one loop Lagrangian is then applied to the computation of the charged Higgs decays. The sizes of the supersymmetric loop correction on branching ratios of the charged Higgs H + (H - ) into the decay modes tb-bar (t-barb), τ-barν τ (τν-bar τ ), and χ i + χ j 0 (χ i - χ j 0 )(i=1,2; j=1-4) are investigated and the supersymmetric loop correction is found to be significant, i.e., in the range 20-30 % in significant regions of the parameter space. The loop correction to the decay mode χ 1 ± χ 2 0 is examined in specific detail as this decay mode leads to a trileptonic signal. The effects of CP phases on the branching ratio are also investigated. A brief discussion of the implications of the analysis for colliders is given

The one-loop Green's functions of dimensionally reduced gauge theories

International Nuclear Information System (INIS)

Ketov, S.V.; Prager, Y.S.

1988-01-01

The dimensional regularization technique as well as that by dimensional reduction is applied to the calculation of the regularized one-loop Green's functions in dsub(o)-dimensional Yang-Mills theory with real massless scalars and spinors in arbitrary (real) representations of a gauge group G. As a particular example, the super-symmetrically regularized one-loop Green's functions of the N=4 supersymmetric Yang-Mills model are derived. (author). 17 refs

Supersymmetric Hybrid Inflation with Non-Minimal Kähler potential

CERN Document Server

Bastero-Gil, M; Shafi, Q

2007-01-01

Minimal supersymmetric hybrid inflation based on a minimal Kahler potential predicts a spectral index n_s\\gsim 0.98. On the other hand, WMAP three year data prefers a central value n_s \\approx 0.95. We propose a class of supersymmetric hybrid inflation models based on the same minimal superpotential but with a non-minimal Kahler potential. Including radiative corrections using the one-loop effective potential, we show that the prediction for the spectral index is sensitive to the small non-minimal corrections, and can lead to a significantly red-tilted spectrum, in agreement with WMAP.

Finiteness of Ricci flat supersymmetric non-linear sigma-models

International Nuclear Information System (INIS)

Alvarez-Gaume, L.; Ginsparg, P.

1985-01-01

Combining the constraints of Kaehler differential geometry with the universality of the normal coordinate expansion in the background field method, we study the ultraviolet behavior of 2-dimensional supersymmetric non-linear sigma-models with target space an arbitrary riemannian manifold M. We show that the constraint of N=2 supersymmetry requires that all counterterms to the metric beyond one-loop order are cohomologically trivial. It follows that such supersymmetric non-linear sigma-models defined on locally symmetric spaces are super-renormalizable and that N=4 models are on-shell ultraviolet finite to all orders of perturbation theory. (orig.)

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

Effects of the supersymmetric phases on the neutral Higgs sector

International Nuclear Information System (INIS)

Demir, D.A.

1999-01-01

By using the effective potential approximation and taking into account the dominant top quark and scalar top quark loops, radiative corrections to MSSM Higgs potential are computed in the presence of the supersymmetric CP-violating phases. It is found that, the lightest Higgs scalar remains essentially CP-even as in the CP-invariant theory whereas the other two scalars are heavy and do not have definite CP properties. The supersymmetric CP-violating phases are shown to modify significantly the decay rates of the scalars to fermion pairs. (author)

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.

SQED two-loop beta function in the context of Implicit regularization

International Nuclear Information System (INIS)

Cherchiglia, Adriano Lana; Sampaio, Marcos; Nemes, Maria Carolina

2013-01-01

Full text: In this work we present the state-of-art for Implicit Regularization (IReg) in the context of supersymmetric theories. IReg is a four-dimensional regularization technique in momentum space which disentangles, in a consistent way at arbitrary order, the divergencies, regularization dependent and finite parts of any Feynman amplitude. Since it does not resort to modifications on the physical space-time dimensions of the underlying quantum field theoretical model, it can be consistently applied to supersymmetric theories. First we describe the technique and present previous results for supersymmetric models: the two-loop beta function for the Wess-Zumino model (both in the component and superfield formalism); the two-loop beta function for Super Yang-Mills (in the superfield formalism using the background field technique). After, we present our calculation of the two-loop beta function for massless and massive SQED using the superfield formalism with and without resorting to the background field technique. We find that only in the second case the two-loop divergence cancels out. We argue it is due to an anomalous Jacobian under the rescaling of the fields in the path-integral which is necessary for the application of the supersymmetric background field technique. We find, however, that in both cases the two-loop coefficients of beta function are non-null. Finally we briefly discuss the anomaly puzzle in the context of our technique. (author)

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

Stability of mass hierarchy in locally supersymmetric grand unification

International Nuclear Information System (INIS)

Nishino, H.; Helayel-Neto, J.A.; Koh, I.G.

1984-06-01

Some locally supersymmetric SU(5) grand unified models with a sliding singlet and two pairs of 5sub(tilde) and 5sub(tilde)* Higgs multiplets are considered from the viewpoint of universal baryon asymmetry and the one-loop stability of mass hierarchy. A new mechanism based on ''sliding singlet reflection symmetry'' to avoid the problem of the mass hierarchical stability is proposed. The stability is shown up to two-loop levels for some models. All order stability is also discussed. (author)

The light bound states of N=1 supersymmetric SU(3) Yang-Mills theory on the lattice

Science.gov (United States)

Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp

2018-03-01

In this article we summarise our results from numerical simulations of N=1 supersymmetric Yang-Mills theory with gauge group SU(3). We use the formulation of Curci and Veneziano with clover-improved Wilson fermions. The masses of various bound states have been obtained at different values of the gluino mass and gauge coupling. Extrapolations to the limit of vanishing gluino mass indicate that the bound states form mass-degenerate supermultiplets.

On supersymmetric effective theories of axion

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kitano, Ryuichiro [Tohoku Univ., Sendai (Japan). Dept. of Physics

2011-04-15

We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

Renormalization of vacuum expectation values in spontaneously broken gauge theories: two-loop results

International Nuclear Information System (INIS)

Sperling, Marcus; Stöckinger, Dominik; Voigt, Alexander

2014-01-01

We complete the two-loop calculation of β-functions for vacuum expectation values (VEVs) in gauge theories by the missing O(g 4 )-terms. The full two-loop results are presented for generic and supersymmetric theories up to two-loop level in arbitrary R ξ -gauge. The results are obtained by means of a scalar background field, identical to our previous analysis. As a by-product, the two-loop scalar anomalous dimension for generic supersymmetric theories is presented. As an application we compute the β-functions for VEVs and tan β in the MSSM, NMSSM, and E 6 SSM

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.

Lattice chiral symmetry and the Wess-Zumino model

International Nuclear Information System (INIS)

Fujikawa, Kazuo; Ishibashi, Masato

2002-01-01

A lattice regularization of the supersymmetric Wess-Zumino model is studied by using Ginsparg-Wilson operators. We recognize a certain conflict between the lattice chiral symmetry and the Majorana condition for Yukawa couplings, or in Weyl representation a conflict between the lattice chiral symmetry and Yukawa couplings. This conflict is also related, though not directly, to the fact that the kinetic (Kaehler) term and the superpotential term are clearly distinguished in the continuum Wess-Zumino model, whereas these two terms are mixed in the Ginsparg-Wilson operators. We illustrate a case where lattice chiral symmetry together with naive Bose-Fermi symmetry is imposed by preserving a SUSY-like symmetry in the free part of the Lagrangian; one-loop level non-renormalization of the superpotential is then maintained for finite lattice spacing, though the finite parts of wave function renormalization deviate from the supersymmetric value. All these properties hold for the general Ginsparg-Wilson algebra independently of the detailed construction of lattice Dirac operators

Consistent Perturbative Fixed Point Calculations in QCD and Supersymmetric QCD

DEFF Research Database (Denmark)

Ryttov, Thomas A.

2016-01-01

order by order in $\\Delta_f$. We then compute $\\gamma_*$ through $O(\\Delta_f^2)$ for supersymmetric QCD in the $\\overline{\\text{DR}}$ scheme and find that it matches the exact known result. We find that $\\gamma_*$ is astonishingly well described in perturbation theory already at the few loops level...

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

Explicit form of non-Abelian self-consistent chiral supersymmetric anomaly

International Nuclear Information System (INIS)

Krivoshchekov, V.K.; Medvedev, P.B.; Chekhov, L.O.; AN SSSR, Leningrad. Matematicheskij Inst.)

1986-01-01

An explicit form for non-abelian supersymmetric chiral anomaly is obtained by means of invariant supersymmetric regularization representing a special type of regularization by loops. Parametrical integrals were not introduced in the calculation but simple expansion in 1/m 2 was used (Mi-regularization parameters having mass quantity). The given result represents an infinite series, that permits to carry out explicit test of the condition of agreement in a closed form. The formula naturally reproduces the component result up to the third order in the Wess-Zumino gauge. It is proved in the abelian limit that the obtained result is transformed into a polynomial of the third order by V

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.

The supersymmetric Higgs sector and $B-\\overline{B}$ mixing for large tan $\\beta$

CERN Document Server

Gorbahn, Martin; Nierste, Ulrich; Trine, Stephanie

2009-01-01

We match the Higgs sector of the most general flavour breaking and CP violating minimal supersymmetric standard model (MSSM) onto a generic two-Higgs-doublet model, paying special attention to the definition of tan beta in the effective theory. In particular no tan beta-enhanced loop corrections appear in the relation to tan beta defined in the DRbar scheme in the MSSM. The corrections to the Higgs-mediated flavour-changing amplitudes which result from this matching are especially relevant for the B_d and B_s mass differences dM_s,d for minimal flavour violation, where the superficially leading contribution vanishes. We give a symmetry argument to explain this cancellation and perform a systematic study of all Higgs-mediated effects, including Higgs loops. The corrections to dM_s are at most 7% for mu>0 and M_A tau^+ nu or B -> X_s gamma. We further update supersymmetric loop corrections to the Yukawa couplings, where we include all possible CP-violating phases and correct errors in the literature. The possi...

Non-renormalizability of supersymmetric non-linear sigma models in four dimensions

International Nuclear Information System (INIS)

Spence, B.

1985-01-01

The one-loop, on-shell, ultraviolet-divergent part of the effective action is calculated for the N=1 and 2 supersymmetric non-linear sigma models in four dimensions. These infinities cannot be absorbed into a redefinition of the bare Kaehler potential and the theories are not renormalizable. (orig.)

Two new supersymmetric equations of Harry Dym type and their supersymmetric reciprocal transformations

International Nuclear Information System (INIS)

Tian, Kai; Liu, Q.P.

2012-01-01

A new N=1 supersymmetric Harry Dym equation is constructed by applying supersymmetric reciprocal transformation to a trivial supersymmetric Harry Dym equation, and its recursion operator and Lax formulation are also obtained. Within the framework of symmetry approach, a class of 3rd order supersymmetric equations of Harry Dym type are considered. In addition to five known integrable equations, a new supersymmetric equation, admitting 5th order generalized symmetry, is shown to be linearizable through supersymmetric reciprocal transformation. Furthermore, its Lax representation and recursion operator are given so that the integrability of this new equation is confirmed. -- Highlights: ► A new supersymmetric Harry Dym equation is constructed through supersymmetric reciprocal transformations. ► The recursion operator and Lax formulation are established for the new supersymmetric Harry Dym equation. ► A supersymmetric equation of Harry Dym type is shown to be linearized through supersymmetric reciprocal transformation.

Excited hexagon Wilson loops for strongly coupled N=4 SYM

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Kotanski, J. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Schomerus, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics and Astronomy

2010-10-15

This work is devoted to the six-gluon scattering amplitude in strongly coupled N=4 supersymmetric Yang-Mills theory. At weak coupling, an appropriate high energy limit of the so-called remainder function, i.e. of the deviation from the BDS formula, may be understood in terms of the lowest eigenvalue of the BFKL hamiltonian. According to Alday et al., amplitudes in the strongly coupled theory can be constructed through an auxiliary 1-dimensional quantum system. We argue that certain excitations of this quantum system determine the Regge limit of the remainder function at strong coupling and we compute its precise value. (orig.)

More on non-supersymmetric asymmetric orbifolds with vanishing cosmological constant

International Nuclear Information System (INIS)

Sugawara, Yuji; Wada, Taiki

2016-01-01

We explore various non-supersymmetric type II string vacua constructed based on asymmetric orbifolds of tori with vanishing cosmological constant at the one loop. The string vacua we present are modifications of the models studied in http://dx.doi.org/10.1007/JHEP02(2016)184, of which orbifold group is just generated by a single element. We especially focus on two types of modifications: (i) the orbifold twists include different types of chiral reflections not necessarily removing massless Rarita-Schwinger fields in the 4-dimensional space-time, (ii) the orbifold twists do not include the shift operator. We further discuss the unitarity and stability of constructed non-supersymmetric string vacua, with emphasizing the common features of them.

Higgs Amplitudes from N=4 Supersymmetric Yang-Mills Theory.

Science.gov (United States)

Brandhuber, Andreas; Kostacińska, Martyna; Penante, Brenda; Travaglini, Gabriele

2017-10-20

Higgs plus multigluon amplitudes in QCD can be computed in an effective Lagrangian description. In the infinite top-mass limit, an amplitude with a Higgs boson and n gluons is computed by the form factor of the operator TrF^{2}. Up to two loops and for three gluons, its maximally transcendental part is captured entirely by the form factor of the protected stress tensor multiplet operator T_{2} in N=4 supersymmetric Yang-Mills theory. The next order correction involves the calculation of the form factor of the higher-dimensional, trilinear operator TrF^{3}. We present explicit results at two loops for three gluons, including the subleading transcendental terms derived from a particular descendant of the Konishi operator that contains TrF^{3}. These are expressed in terms of a few universal building blocks already identified in earlier calculations. We show that the maximally transcendental part of this quantity, computed in nonsupersymmetric Yang-Mills theory, is identical to the form factor of another protected operator, T_{3}, in the maximally supersymmetric theory. Our results suggest that the maximally transcendental part of Higgs amplitudes in QCD can be entirely computed through N=4 super Yang-Mills theory.

Effective action of softly broken supersymmetric theories

International Nuclear Information System (INIS)

Groot Nibbelink, S.; Nyawelo, T.S

2006-12-01

We study the renormalization of (softly) broken supersymmetric theories at the one loop level in detail. We perform this analysis in a superspace approach in which the supersymmetry breaking interactions are parameterized using spurion insertions. We comment on the uniqueness of this parameterization. We compute the one loop renormalization of such theories by calculating superspace vacuum graphs with multiple spurion insertions. To preform this computation efficiently we develop algebraic properties of spurion operators, that naturally arise because the spurions are often surrounded by superspace projection operators. Our results are general apart from the restrictions that higher super covariant derivative terms and some finite effects due to non-commutativity of superfield dependent mass matrices are ignored. One of the soft potentials induces renormalization of the Kaehler potential. (author)

Simple perturbative renormalization scheme for supersymmetric gauge theories

Energy Technology Data Exchange (ETDEWEB)

Foda, O.E. (Purdue Univ., Lafayette, IN (USA). Dept. of Physics)

1983-06-30

We show that the manifestly supersymmetric and gauge-invariant results of Supersymmetric Dimensional renormalization (SDR) are reproduceable through a simple, and mathematically consistent perturbative renormalization technique, where regularization is attained via a map that deforms the momentum space Feynman integrands in a specific way. In particular, it introduces a multiplicative factor of ((p+q)/..delta..)/sup -/delta in each momentum-space loop integral, where p is the magnitude of the loop momentum, q is an arbitrary constant to be chosen as will be explained, thus compensating for loss of translation invariance in p, ..lambda.. is a renormalization mass, and delta is a suitable non-integer: the analog of epsilon in dimensional schemes. All Dirac algebra and integration are four-dimensional, and renormalization is achieved by subtracting poles in delta, followed by setting delta->O. The mathematical inconsistencies of SDR are evaded by construction, since the numbers of fermion and boson degrees of freedom remain unchanged but analytic continuation in the number of dimensions is bypassed. Thus, the technique is equally viable in component and in superfield formalisms, and all anomalies are realized. The origin of the chiral anomaly is that no choice of q satisfies both gauge and chiral Ward identities simultaneously.

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.

Searching for beyond the minimal supersymmetric standard model at the laboratory and in the sky

Energy Technology Data Exchange (ETDEWEB)

Kim, Ju Min

2010-09-15

We study the collider signals as well as Dark Matter candidates in supersymmetric models. We show that the collider signatures from a supersymmetric Grand Unification model based on the SO(10) gauge group can be distinguishable from those from the (constrained) minimal supersymmetric Standard Model, even though they share some common features. The N=2 supersymmetry has the characteristically distinct phenomenology, due to the Dirac nature of gauginos, as well as the extra adjoint scalars. We compute the cold Dark Matter relic density including a class of one-loop corrections. Finally, we discuss the detectability of neutralino Dark Matter candidate of the SO(10) model by the direct and indirect Dark Matter search experiments. (orig.)

Searching for beyond the minimal supersymmetric standard model at the laboratory and in the sky

International Nuclear Information System (INIS)

Kim, Ju Min

2010-09-01

We study the collider signals as well as Dark Matter candidates in supersymmetric models. We show that the collider signatures from a supersymmetric Grand Unification model based on the SO(10) gauge group can be distinguishable from those from the (constrained) minimal supersymmetric Standard Model, even though they share some common features. The N=2 supersymmetry has the characteristically distinct phenomenology, due to the Dirac nature of gauginos, as well as the extra adjoint scalars. We compute the cold Dark Matter relic density including a class of one-loop corrections. Finally, we discuss the detectability of neutralino Dark Matter candidate of the SO(10) model by the direct and indirect Dark Matter search experiments. (orig.)

Green-Schwarz action and loop calculations for superstring

International Nuclear Information System (INIS)

Kallosh, R.; Morozov, A.

1988-01-01

The authors that Green-Schwartz explicitly 10d supersymmetric and 2d covariant approach without spin 1/2 and 3/2 fields on world sheet may appear suitable for calculations of loops in superstring theory. The way the cancellation of Polyakov anomaly is realized and the answer for 1-loop 4-point amplitudes are reproduced

NLL resummation for the static potential in N=4 SYM theory

International Nuclear Information System (INIS)

Stahlhofen, Maximilian

2012-09-01

We determine the complete NLL running of the static potential associated with the locally 1/2 BPS Wilson loop in N=4 supersymmetric Yang-Mills theory. We present results for the SU(N c ) singlet as well as for the adjoint configuration and arbitrary N c at weak coupling. In order to derive the respective anomalous dimensions we perform a two-loop calculation in the N=4 supersymmetric version of the effective field theory pNRQCD. In addition we confirm the recently obtained fixed-order result for the singlet static potential generated exclusively by ladder diagrams to the third order in the t'Hooft coupling. We also give an explicit expression for the logarithmic contribution of all non-ladder diagrams at this order.

NLL resummation for the static potential in N=4 SYM theory

Energy Technology Data Exchange (ETDEWEB)

Stahlhofen, Maximilian [Wien Univ. (Austria). Fakultaet fuer Physik

2012-09-15

We determine the complete NLL running of the static potential associated with the locally 1/2 BPS Wilson loop in N=4 supersymmetric Yang-Mills theory. We present results for the SU(N{sub c}) singlet as well as for the adjoint configuration and arbitrary N{sub c} at weak coupling. In order to derive the respective anomalous dimensions we perform a two-loop calculation in the N=4 supersymmetric version of the effective field theory pNRQCD. In addition we confirm the recently obtained fixed-order result for the singlet static potential generated exclusively by ladder diagrams to the third order in the t'Hooft coupling. We also give an explicit expression for the logarithmic contribution of all non-ladder diagrams at this order.

Complete on-shell renormalization scheme for the minimal supersymmetric Higgs sector

International Nuclear Information System (INIS)

Chankowski, P.H.; Pokorski, Stefan; Rosiek, Janusz

1994-01-01

A systematic on-shell renormalization programme is carried out for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model. Complete one-loop results for the 2- and 3-point Green's functions are explicitly given. The Higgs boson masses and the production cross sections in the e + e - colliders are calculated. ((orig.))

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.

LHC phenomenology and higher order electroweak corrections in supersymmetric models with and without R-parity

Energy Technology Data Exchange (ETDEWEB)

Liebler, Stefan Rainer

2011-09-15

The standard model of particle physics lacks on some shortcomings from experimental as well as from theoretical point of view: There is no approved mechanism for the generation of masses of the fundamental particles, in particular also not for the light, but massive neutrinos. In addition the standard model does not provide an explanation for the observance of dark matter in the universe. Moreover the gauge couplings of the three forces in the standard model do not unify, implying that a fundamental theory combining all forces can not be formulated. Within this thesis we address supersymmetric models as answers to these various questions, but instead of focusing on the most simple supersymmetrization of the standard model, we consider basic extensions, namely the next-to-minimal supersymmetric standard model (NMSSM), which contains an additional singlet field, and R-parity violating models. Using lepton number violating terms in the context of bilinear R-parity violation and the {mu}{nu}SSM we are able to explain neutrino physics intrinsically supersymmetric, since those terms induce a mixing between the neutralinos and the neutrinos. This thesis works out the phenomenology of the supersymmetric models under consideration and tries to point out differences to the well-known features of the simplest supersymmetric realization of the standard model. In case of the R-parity violating models the decays of the light neutralinos can result in displaced vertices. In combination with a light singlet state these displaced vertices might offer a rich phenomenology like non-standard Higgs decays into a pair of singlinos decaying with displaced vertices. Within this thesis we present some calculations at next order of perturbation theory, since one-loop corrections provide possibly large contributions to the tree-level masses and decay widths. We are using an on-shell renormalization scheme to calculate the masses of neutralinos and charginos including the neutrinos and

LHC phenomenology and higher order electroweak corrections in supersymmetric models with and without R-parity

International Nuclear Information System (INIS)

Liebler, Stefan Rainer

2011-09-01

The standard model of particle physics lacks on some shortcomings from experimental as well as from theoretical point of view: There is no approved mechanism for the generation of masses of the fundamental particles, in particular also not for the light, but massive neutrinos. In addition the standard model does not provide an explanation for the observance of dark matter in the universe. Moreover the gauge couplings of the three forces in the standard model do not unify, implying that a fundamental theory combining all forces can not be formulated. Within this thesis we address supersymmetric models as answers to these various questions, but instead of focusing on the most simple supersymmetrization of the standard model, we consider basic extensions, namely the next-to-minimal supersymmetric standard model (NMSSM), which contains an additional singlet field, and R-parity violating models. Using lepton number violating terms in the context of bilinear R-parity violation and the μνSSM we are able to explain neutrino physics intrinsically supersymmetric, since those terms induce a mixing between the neutralinos and the neutrinos. This thesis works out the phenomenology of the supersymmetric models under consideration and tries to point out differences to the well-known features of the simplest supersymmetric realization of the standard model. In case of the R-parity violating models the decays of the light neutralinos can result in displaced vertices. In combination with a light singlet state these displaced vertices might offer a rich phenomenology like non-standard Higgs decays into a pair of singlinos decaying with displaced vertices. Within this thesis we present some calculations at next order of perturbation theory, since one-loop corrections provide possibly large contributions to the tree-level masses and decay widths. We are using an on-shell renormalization scheme to calculate the masses of neutralinos and charginos including the neutrinos and leptons in

Iterative structure within the five-particle two-loop amplitude

International Nuclear Information System (INIS)

Cachazo, Freddy; Spradlin, Marcus; Volovich, Anastasia

2006-01-01

We find an unexpected iterative structure within the two-loop five-gluon amplitude in N=4 supersymmetric Yang-Mills theory. Specifically, we show that a subset of diagrams contributing to the full amplitude, including a two-loop pentagon-box integral with nontrivial dependence on five kinematical variables, satisfies an iterative relation in terms of one-loop scalar box diagrams. The implications of this result for the possible iterative structure of the full two-loop amplitude are discussed

Supersymmetrical dual string theories and their field theory limits: A review

International Nuclear Information System (INIS)

Green, M.B.

1985-01-01

This paper outlines the construction and properties of supersymmetric string theories. Such theories, which describe the quantum mechanics of relativistic strings in ten-space time dimensions contain both N=4 Yang-Mills and N=8 supergravity field theories as special limits in which the string tension becomes infinite. Calculations of one-loop S-matrix elements reveal remarkable finiteness properties

Chiral rings and anomalies in supersymmetric gauge theory

International Nuclear Information System (INIS)

Cachazo, Freddy; Witten, Edward; Seiberg, Nathan; Douglas, Michael R.

2002-01-01

Motivated by recent work of Dijkgraaf and Vafa, we study anomalies and the chiral ring structure in a supersymmetric U(N) gauge theory with an adjoint chiral superfield and an arbitrary superpotential. A certain generalization of the Konishi anomaly leads to an equation which is identical to the loop equation of a bosonic matrix model. This allows us to solve for the expectation values of the chiral operators as functions of a finite number of 'integration constants'. From this, we can derive the Dijkgraaf-Vafa relation of the effective superpotential to a matrix model. Some of our results are applicable to more general theories. For example, we determine the classical relations and quantum deformations of the chiral ring of N=1 super Yang-Mills theory with SU(N) gauge group, showing, as one consequence, that all supersymmetric vacua of this theory have a nonzero chiral condensate. (author)

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.)

A simple perturbative renormalization scheme for supersymmetric gauge theories

International Nuclear Information System (INIS)

Foda, O.E.

1983-01-01

We show that the manifestly supersymmetric and gauge-invariant results of Supersymmetric Dimensional renormalization (SDR) are reproduceable through a simple, and mathematically consistent perturbative renormalization technique, where regularization is attained via a map that deforms the momentum space Feynman integrands in a specific way. In particular, it introduces a multiplicative factor of [(p+q)/δ] - delta in each momentum-space loop integral, where p is the magnitude of the loop momentum, q is an arbitrary constant to be chosen as will be explained, thus compensating for loss of translation invariance in p, #betta# is a renormalization mass, and delta is a suitable non-integer: the analog of epsilon in dimensional schemes. All Dirac algebra and integration are four-dimensional, and renormalization is achieved by subtracting poles in delta, followed by setting delta->O. The mathematical inconsistencies of SDR are evaded by construction, since the numbers of fermion and boson degrees of freedom remain unchanged but analytic continuation in the number of dimensions is bypassed. Thus, the technique is equally viable in component and in superfield formalisms, and all anomalies are realized. The origin of the chiral anomaly is that no choice of q satisfies both gauge and chiral Ward identities simultaneously. (orig.)

Non-minimal supersymmetric models. LHC phenomenolgy and model discrimination

Energy Technology Data Exchange (ETDEWEB)

Krauss, Manuel Ernst

2015-12-18

It is generally agreed upon the fact that the Standard Model of particle physics can only be viewed as an effective theory that needs to be extended as it leaves some essential questions unanswered. The exact realization of the necessary extension is subject to discussion. Supersymmetry is among the most promising approaches to physics beyond the Standard Model as it can simultaneously solve the hierarchy problem and provide an explanation for the dark matter abundance in the universe. Despite further virtues like gauge coupling unification and radiative electroweak symmetry breaking, minimal supersymmetric models cannot be the ultimate answer to the open questions of the Standard Model as they still do not incorporate neutrino masses and are besides heavily constrained by LHC data. This does, however, not derogate the beauty of the concept of supersymmetry. It is therefore time to explore non-minimal supersymmetric models which are able to close these gaps, review their consistency, test them against experimental data and provide prospects for future experiments. The goal of this thesis is to contribute to this process by exploring an extraordinarily well motivated class of models which bases upon a left-right symmetric gauge group. While relaxing the tension with LHC data, those models automatically include the ingredients for neutrino masses. We start with a left-right supersymmetric model at the TeV scale in which scalar SU(2){sub R} triplets are responsible for the breaking of left-right symmetry as well as for the generation of neutrino masses. Although a tachyonic doubly-charged scalar is present at tree-level in this kind of models, we show by performing the first complete one-loop evaluation that it gains a real mass at the loop level. The constraints on the predicted additional charged gauge bosons are then evaluated using LHC data, and we find that we can explain small excesses in the data of which the current LHC run will reveal if they are actual new

Exact Results for 't Hooft Loops in Gauge Theories on S^4

CERN Document Server

Gomis, Jaume; Pestun, Vasily

2012-01-01

The path integral of a general N=2 supersymmetric gauge theory on S^4 is exactly evaluated in the presence of a supersymmetric 't Hooft loop operator. The result we find - obtained using localization techniques - captures all perturbative quantum corrections as well as non-perturbative effects due to instantons and monopoles, which are supported at the north pole, south pole and equator of S^4. As a by-product, our gauge theory calculations successfully confirm the predictions made for 't Hooft loops obtained from the calculation of topological defect correlators in Liouville/Toda conformal field theory.

Two-loop contributions in the supersymmetric Higgs sector

International Nuclear Information System (INIS)

Rzehak, H.A.

2005-01-01

Corrections to the one-loop contributions of the order O(α b ) with α b =λ b 62/(4π) within the MSSM with real parameters are the main topic in the first part of the thesis. The mass of the lightest Higgs boson was calculated up to order O(α b αs) for arbitrary tan β by means of the Feynman-diagrammatic method. In the bottom-sbottom sector four renormalization schemes were studied. With a suitably chosen bottom-Yukawa coupling the leading tan β-amplified corrections, which result from the bottom-sbottom sector, can be regarded already on the one-loop level. For this in the present thesis the bottom quark mass in the DR scheme with a resummation of the tan β-amplified terms was applied. In the analysis especially the non-leading contributions, which exceed in a complete calculation of the order O(α b α s ) corrections the one-loop result with resummed tan β-amplified terms. In the second part of the thesis the main topic lied on the study of the order O(α t α s ) corrections in the MSSM with complex parameters

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.

Supersymmetric mechanics

International Nuclear Information System (INIS)

Stelle, Kellogg S

2007-01-01

With the development of the electronic archives in high-energy physics, there has been increasing questioning of the role of traditional publishing styles, particularly in the production of conference books. One aspect of traditional publishing that still receives wide appreciation, however, is in the production of well-focussed pedagogical material. The present two-volume edition, 'Supersymmetric Mechanics-Vol 1', edited by S Bellucci and 'Supersymmetric Mechanics-Vol 2', edited by S Bellucci, S Ferrara and A Marrani, is a good example of the kind of well-digested presentation that should still find its way into university libraries. This two-volume set presents the material of a set of pedagogical lectures presented at the INFN National Laboratory in Frascati over a two-year period on the subject of supersymmetric mechanics. The articles include the results of discussions with the attending students after the lectures. Overall, this makes for a useful compilation of material on a subject that underlies much of the current effort in supersymmetric approaches to cosmology and the unification programme. The first volume comprises articles on 'A journey through garden algebras' by S Bellucci, S J Gates Jr and E Orazi on linear supermultiplet realizations in supersymmetric mechanics,'Supersymmetric mechanics in superspace' by S Bellucci and S Krivonos, 'Noncommutative mechanics, Landau levels, twistors and Yang-Mills amplitudes' by V P Nair, 'Elements of (super) Hamiltonian formalism' by A Nersessian and 'Matrix mechanics' by C Sochichiu. The second volume consists entirely of a masterful presentation on 'The attractor mechanism and space time singularities' by S Ferrara. This presents a comprehensive and detailed overview of the structure of supersymmetric black hole solutions in supergravity, critical point structure in the scalar field moduli space and the thermodynamic consequences. This second volume alone makes the set a worthwhile addition to the research

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

Implications of a heavy top in supersymmetric theories

CERN Document Server

Leontaris, George K

1995-01-01

In the context of the radiative electroweak symmetry breaking scenario we investigate the implications of a heavy top quark mass, close to its infrared fixed point, on the low energy parameters of the minimal supersymmetric standard model. We use analytic expressions to calculate the Higgs masses as well as the supersymmetric masses of the third generation. We further assume bottom-tau unification at the GUT scale and examine the constraints put by this condition on the parameter space (\\tan\\beta,\\alpha_3), using the renormalization group procedure at the two-loop level. We find only a small fraction of the parameter space where the above conditions can be satisfied, namely 1\\le \\tan\\beta \\le 2, while 0.111\\le\\alpha_3(M_Z) \\le 0.118. We further analyse the case where all three Yukawa couplings reach the perturbative limit just after the unification scale. In this latter case, the situation turns out to be very strict demanding \\tan\\beta\\sim 63.

On low-energy effective action in three-dimensional = 2 and = 4 supersymmetric electrodynamics

Science.gov (United States)

Buchbinder, I. L.; Merzlikin, B. S.; Samsonov, I. B.

2013-11-01

We discuss general structure of low-energy effective actions in = 2 and = 4 three-dimensional supersymmetric electrodynamics (SQED) in gauge superfield sector. There are specific terms in the effective action having no four-dimensional analogs. Some of these terms are responsible for the moduli space metric in the Coulomb branch of the theory. We find two-loop quantum corrections to the moduli space metric in the = 2 SQED and show that in the = 4 SQED the moduli space does not receive two-loop quantum corrections.

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.

Supersymmetric color superconductivity

International Nuclear Information System (INIS)

Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi

2003-01-01

Recent interest in novel phases in high density QCD motivates the study of high density supersymmetric QCD (SQCD), where powerful exact results for supersymmetric gauge theories can be brought to bear in the strongly coupled regime. We begin by describing how a chemical potential can be incorporated into a supersymmetric theory as a spurion vector superfield. We then study supersymmetric SU(N c ) gauge theories with N f flavors of quarks in the presence of a baryon chemical potential μ, and describe the global symmetry breaking patterns at low energy. Our analysis requires μ > Λ. We find that for N F c a modified U(1) B symmetry is preserved, analogous to the non-supersymmetric 2SC phase, whereas for N f = N c there is a critical chemical potential above which the U(1) B is broken, as it is in the non-supersymmetric CFL phase. We further analyze the cases with N c + 1 (le) N f c and find that baryon number is broken dynamically for μ > μ c . We also give a qualitative description of the phases in the ''conformal window'', 3/2 N c f c , at finite density

Supersymmetric color superconductivity

International Nuclear Information System (INIS)

Harnik, Roni; Larson, Daniel T.; Murayama, Hitoshi

2004-01-01

Recent interest in novel phases in high density QCD motivates the study of high density supersymmetric QCD (SQCD), where powerful exact results for supersymmetric gauge theories can be brought to bear in the strongly coupled regime. We begin by describing how a chemical potential can be incorporated into a supersymmetric theory as a spurion vector superfield. We then study supersymmetric SU(N c ) gauge theories with N f flavors of quarks in the presence of a baryon chemical potential mu, and describe the global symmetry breaking patterns at low energy. Our analysis requires μ f c a modified U(1) B symmetry is preserved, analogous to the non-supersymmetric 2SC phase, whereas for N f =N c there is a critical chemical potential above which the U(1) B is broken, as it is in the non-supersymmetric CFL phase. We further analyze the cases with N c +1≤ N f c and find that baryon number is broken dynamically for μ > mu c . We also give a qualitative description of the phases in the 'conformal window', 3/2 N c f c , at finite density. (author)

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

Gluons and gravitons at one loop from ambitwistor strings

Science.gov (United States)

Geyer, Yvonne; Monteiro, Ricardo

2018-03-01

We present new and explicit formulae for the one-loop integrands of scattering amplitudes in non-supersymmetric gauge theory and gravity, valid for any number of particles. The results exhibit the colour-kinematics duality in gauge theory and the double-copy relation to gravity, in a form that was recently observed in supersymmetric theories. The new formulae are expressed in a particular representation of the loop integrand, with only one quadratic propagator, which arises naturally from the framework of the loop-level scattering equations. The starting point in our work are the expressions based on the scattering equations that were recently derived from ambitwistor string theory. We turn these expressions into explicit formulae depending only on the loop momentum, the external momenta and the external polarisations. These formulae are valid in any number of spacetime dimensions for pure Yang-Mills theory (gluon) and its natural double copy, NS-NS gravity (graviton, dilaton, B-field), and we also present formulae in four spacetime dimensions for pure gravity (graviton). We perform several tests of our results, such as checking gauge invariance and directly matching our four-particle formulae to previously known expressions. While these tests would be elaborate in a Feynman-type representation of the loop integrand, they become straightforward in the representation we use.

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.

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

Supersymmetric reciprocal transformation and its applications

International Nuclear Information System (INIS)

Liu, Q. P.; Popowicz, Ziemowit; Tian Kai

2010-01-01

The supersymmetric analog of the reciprocal transformation is introduced. This is used to establish a transformation between one of the supersymmetric Harry Dym equations and the supersymmetric modified Korteweg-de Vries equation. The reciprocal transformation, as a Baecklund-type transformation between these two equations, is adopted to construct a recursion operator for the supersymmetric Harry Dym equation. By proper factorization of the recursion operator, a bi-Hamiltonian structure is found for the supersymmetric Harry Dym equation. Furthermore, a supersymmetric Kawamoto equation is proposed and is associated with the supersymmetric Sawada-Kotera equation. The recursion operator and odd bi-Hamiltonian structure of the supersymmetric Kawamoto equation are also constructed.

Supersymmetric classical mechanics

International Nuclear Information System (INIS)

Biswas, S.N.; Soni, S.K.

1986-01-01

The purpose of the paper is to construct a supersymmetric Lagrangian within the framework of classical mechanics which would be regarded as a candidate for passage to supersymmetric quantum mechanics. 5 refs. (author)

Wilson lines for AdS5 black strings

International Nuclear Information System (INIS)

Hristov, Kiril; Katmadas, Stefanos

2015-01-01

We describe a simple method of extending AdS 5 black string solutions of 5d gauged supergravity in a supersymmetric way by addition of Wilson lines along a circular direction in space. When this direction is chosen along the string, and due to the specific form of 5d supergravity that features Chern-Simons terms, the existence of magnetic charges automatically generates conserved electric charges in a 5d analogue of the Witten effect. Therefore we find a rather generic, model-independent way of adding electric charges to already existing solutions with no backreaction from the geometry or breaking of any symmetry. We use this method to explicitly write down more general versions of the Benini-Bobev black strings (http://dx.doi.org/10.1103/PhysRevLett.110.061601, http://dx.doi.org/10.1007/JHEP06(2013)005) and comment on the implications for the dual field theory and the similarities with generalizations of the Cacciatori-Klemm black holes (http://dx.doi.org/10.1007/JHEP01(2010)085) in AdS 4 .

String-inspired BCJ numerators for one-loop MHV amplitudes

International Nuclear Information System (INIS)

He, Song; Monteiro, Ricardo; Schlotterer, Oliver

2016-01-01

We find simple expressions for the kinematic numerators of one-loop MHV amplitudes in maximally supersymmetric Yang-Mills theory and supergravity, at any multiplicity. The gauge-theory numerators satisfy the Bern-Carrasco-Johansson (BCJ) duality between color and kinematics, so that the gravity numerators are simply the square of the gauge-theory ones. The duality holds because the numerators can be written in terms of structure constants of a kinematic algebra, which is familiar from the BCJ organization of self-dual gauge theory and gravity. The close connection that we find between one-loop amplitudes in the self-dual case and in the maximally supersymmetric case is reminiscent of the dimension-shifting formula. The starting point for arriving at our expressions is the dimensional reduction of ten-dimensional amplitudes obtained in the field-theory limit of open superstrings.

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.

Beta functions and central charge of supersymmetric sigma models with torsion

International Nuclear Information System (INIS)

Guadagnini, E.; Mintchev, M.

1987-01-01

We present a method for the computation of the renormalization group β-functions and the central charge in two-dimensional supersymmetric sigma models in a gravitational background. The two-loops results are exhibited. We use the Pauli-Villars regularization which preserves supersymmetry and permits an unambiguous treatment of the model with torsion. The central charge we derive for a general manifold is in agreement with the expression found on group manifolds. (orig.)

The holomorphicity of the gauge coupling constant in supersymmetric gauge theories

International Nuclear Information System (INIS)

Li, H.

1993-01-01

Holomorphicity is the analytical dependence of the gauge coupling function, f = 1/g 2 + Θ/8π 2 , on the chiral fields in supergravity and supersymmetric gauge theories. The holomorphic property of 1/g 2 in supersymmetric gauge theories is studied by calculating its dependence on the mass matrix. The general representations of the mass matrix allowed by the constraints of gauge invariance is considered, and calculate the one- and two-loop corrections to 1/g 2 for both super QED and super Yang-Mills theories. For the massive mass matrix it is shown that one- and two-loop corrections to the gauge coupling constant are holomorphic. The reason for two-loop holomorphicity is that the second order logarithmic terms cancel out. For the mass matrix with at least one zero mode, it is recognized that there are two distinct cases which we call pseudo massive and intrinsically massless. For the case of pseudo mass matrix, the reducible representation of the gauge group is (i) complex with equal numbers of irreducible representations and their conjugates, (ii) real, or (iii) pseudo-real. Even though there are massless modes, it is found that the dependence of the gauge coupling constant on the mass matrix is holomorphic. This holomorphicity follows because the mass matrix can be perturbed to regularize the infrared divergence. For the case of intrinsically massless mass matrix, a reducible complex representation with unequal numbers of irreducible representations and their conjugates. The author shows that loop corrections to the gauge coupling constant are non-holomorphic. The reason is an infrared momentum cutoff is used which spins holomorphicity. The results show that, for the pseudo massive case, even though there is an infrared divergence, the one- and two-loop corrections are still holomorphic. Hence, it is concluded that non-holomorphicity is caused by the unbalanced numbers of families and antifamilies in the complex representation

Supersymmetric quasipotential equations

International Nuclear Information System (INIS)

Zaikov, R.P.

1981-01-01

A supersymmetric extension of the Logunov-Tavkhelidze quasipotential approach is suggested. The supersymmetric Bethe- Salpeter equation is an initial equation. The transition from the four-time to the two-time Green function is made in the super- center-of-mass system. The two-time Green function has no inverse function in the whole spinor space. The resolvent operator if found using the Majorana character of the spinor wave function. The supersymmetric quasipotential equation is written. The consideration is carried out in the framework of the theory of chiral scalar superfields [ru

Behaviour of coupling constants at high temperature in supersymmetric theories

International Nuclear Information System (INIS)

Swee Ping Chia.

1986-04-01

An analysis is presented of the temperature dependence of the coupling constants using the improved one-loop approximation in the Wess-Zumino model and the supersymmetric O(N) model. It is found that all the coupling constants, both bosonic (Φ 4 type) and Yukawa, approach constant nonzero values as T→∞. The asymptotic values of the bosonic couplings are slightly smaller than the corresponding zero-temperature values, and those of the Yukawa couplings are the same as the zero-temperature values. (author)

Topics in supersymmetric theories

International Nuclear Information System (INIS)

Nemeschansky, D.D.

1984-01-01

This thesis discusses four different topics in supersymmetric theories. In the first part models in which supersymmetry is broken by the Fayet-Iliopoulos mechanism are considered. The possibility that scalar quark and lepton masses might arise radiatively in such theories is explored. In the second part supersymmetric grand unified models with a sliding singlet are considered. The author reviews the argument that the sliding singlet does not work in models with large supersymmetry breaking. Then he considers the possibility of using a sliding singlet with low energy supersymmetry breaking. The third part of the thesis deals with the entropy problem of supersymmetric theories. Most supersymmetric models possess a decoupled particle with mass of order 100 GeV which is copiously produced in the early universe and whose decay produces huge amounts of entropy. The author shows how this problem can be avoided in theories in which the hidden sector contains several light fields. In the fourth part effective Lagrangians for supersymmetric theories are studied. The anomalous pion interaction for supersymmetric theories is written down. General properties of this term are studied both on compact and non-compact manifolds

Loop Amplitudes in Pure Yang-Mills from Generalised Unitarity

OpenAIRE

Brandhuber, Andreas; McNamara, Simon; Spence, Bill; Travaglini, Gabriele

2005-01-01

We show how generalised unitarity cuts in D = 4 - 2 epsilon dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational terms in the amplitudes, as well as the cut-constructible parts. We test the validity of our method by re-deriving the one-loop ++++, -+++, --++, -+-+ and +++++ gluon scattering amplitudes using generalised quadruple cuts and triple cuts in D dimensions.

Loop amplitudes in pure Yang-Mills from generalised unitarity

International Nuclear Information System (INIS)

Brandhuber, Andreas; McNamara, Simon; Spence, Bill; Travaglini, Gabriele

2005-01-01

We show how generalised unitarity cuts in D = 4-2ε dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational terms in the amplitudes, as well as the cut-constructible parts. We test the validity of our method by re-deriving the one-loop ++++, -+++, --++, -+-+ and +++++ gluon scattering amplitudes using generalised quadruple cuts and triple cuts in D dimensions

Loop amplitudes in pure Yang-Mills from generalised unitarity

Energy Technology Data Exchange (ETDEWEB)

Brandhuber, Andreas [Department of Physics, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom); McNamara, Simon [Department of Physics, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom); Spence, Bill [Department of Physics, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom); Travaglini, Gabriele [Department of Physics, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom)

2005-10-15

We show how generalised unitarity cuts in D = 4-2{epsilon} dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational terms in the amplitudes, as well as the cut-constructible parts. We test the validity of our method by re-deriving the one-loop ++++, -+++, --++, -+-+ and +++++ gluon scattering amplitudes using generalised quadruple cuts and triple cuts in D dimensions.

N=4 SUSY Yang-Mills: Three loops made simple(r)

Energy Technology Data Exchange (ETDEWEB)

Dokshitzer, Yu.L. [LPTHE, Universities of Paris-VI and VII and CNRS, Paris (France); Marchesini, G. [University of Milano-Bicocca and INFN Sezione di Milano-Bicocca, Milan (Italy)]. E-mail: marchesini@mib.infn.it

2007-03-15

We construct universal parton evolution equation that produces space- and time-like anomalous dimensions for the maximally super-symmetric N=4 Yang-Mills field theory model, and find that its kernel satisfies the Gribov-Lipatov reciprocity relation in three loops. Given a simple structure of the evolution kernel, this should help to generate the major part of multi-loop contributions to QCD anomalous dimensions, due to classical soft gluon radiation effects.

Supersymmetric domain walls

NARCIS (Netherlands)

Bergshoeff, Eric A.; Kleinschmidt, Axel; Riccioni, Fabio

2012-01-01

We classify the half-supersymmetric "domain walls," i.e., branes of codimension one, in toroidally compactified IIA/IIB string theory and show to which gauged supergravity theory each of these domain walls belong. We use as input the requirement of supersymmetric Wess-Zumino terms, the properties of

Spin analysis of supersymmetric particles

International Nuclear Information System (INIS)

Choi, S.Y.; Martyn, H.U.

2006-12-01

The spin of supersymmetric particles can be determined at e + e - colliders unambiguously. This is demonstrated for a characteristic set of non-colored supersymmetric particles -- smuons, selectrons, and charginos/neutralinos. The analysis is based on the threshold behavior of the excitation curves for pair production in e + e - collisions, the angular distribution in the production process and decay angular distributions. In the first step we present the observables in the helicity formalism for the supersymmetric particles. Subsequently we confront the results with corresponding analyses of Kaluza-Klein particles in theories of universal extra space dimensions which behave distinctly different from supersymmetric theories. It is shown in the third step that a set of observables can be designed which signal the spin of supersymmetric particles unambiguously without any model assumptions. Finally in the fourth step it is demonstrated that the determination of the spin of supersymmetric particles can be performed experimentally in practice at an e + e - collider. (orig.)

Properties of supersymmetric particles and processes

International Nuclear Information System (INIS)

Barnett, R.M.

1986-01-01

The motivations for experimental searches for supersymmetric particles are discussed. The role of R-parity in these searches is described. The production and decay characteristics of each class of supersymmetric particles are investigated in the context of both e+e- and hadron machines. There is a detailed presentation of a sample calculation of a supersymmetric process. Emphasis is given to the signatures for detection of supersymmetric particles and processes. The current limits for supersymmetric particles are given. 125 refs., 50 figs

Supersymmetric particles at LEP

International Nuclear Information System (INIS)

Barbiellini, G.; Coignet, G.; Gaillard, M.K.; Bonneaud, G.; Ellis, J.; Matteuzzi, C.; Wiik, H.

1979-10-01

The authors examine whether the supersymmetrization of nature at a mass scale up to 100 GeV can be confirmed or excluded by experiments with LEP. They review the qualitative features of the spectroscopy suggested by supersymmetric theories. Then they discuss possible production rates and means of detection of these particles at LEP. In this framework they make some remarks about other projects for future high energy physics machines which can be used for the study of supersymmetric phenomena. (HSI)

Supersymmetric Higgs pair discovery prospects at hadron colliders

CERN Document Server

Belyaev, A; Éboli, Oscar J P; Mizukoshi, J K; Novaes, S F

2000-01-01

We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.

Anatomy of Higgs mass in supersymmetric inverse seesaw models

Energy Technology Data Exchange (ETDEWEB)

Chun, Eung Jin, E-mail: ejchun@kias.re.kr [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of); Mummidi, V. Suryanarayana, E-mail: soori9@cts.iisc.ernet.in [Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012 (India); Vempati, Sudhir K., E-mail: vempati@cts.iisc.ernet.in [Centre for High Energy Physics, Indian Institute of Science, Bangalore 560012 (India)

2014-09-07

We compute the one loop corrections to the CP-even Higgs mass matrix in the supersymmetric inverse seesaw model to single out the different cases where the radiative corrections from the neutrino sector could become important. It is found that there could be a significant enhancement in the Higgs mass even for Dirac neutrino masses of O(30) GeV if the left-handed sneutrino soft mass is comparable or larger than the right-handed neutrino mass. In the case where right-handed neutrino masses are significantly larger than the supersymmetry breaking scale, the corrections can utmost account to an upward shift of 3 GeV. For very heavy multi TeV sneutrinos, the corrections replicate the stop corrections at 1-loop. We further show that general gauge mediation with inverse seesaw model naturally accommodates a 125 GeV Higgs with TeV scale stops.

Supersymmetric models without R parity

International Nuclear Information System (INIS)

Ross, G.G.; Valle, J.W.F.

1985-01-01

We show that many supersymmetric models may spontaneously break R parity through scalar neutrinos acquiring a vacuum expectation value (vev). These models allow supersymmetric particles to be produced singly and to decay to nonsupersymmetric states. This leads to a new pattern of supersymmetric phenomenology. We discuss the lepton number violation to be expected in this class of models. (orig.)

Higgs-Boson Two-Loop Contributions to Electric Dipole Moments in the MSSM

CERN Document Server

Pilaftsis, Apostolos

1999-01-01

The complete set of Higgs-boson two-loop contributions to electric dipole moments of the electron and neutron is calculated in the minimal supersymmetric standard model. The electric dipole moments are induced by CP-violating trilinear couplings of the `CP-odd' and charged Higgs bosons to the scalar top and bottom quarks. Numerical estimates of the individual two-loop contributions to electric dipole moments are given.

Supersymmetric extensions of K field theories

Science.gov (United States)

Adam, C.; Queiruga, J. M.; Sanchez-Guillen, J.; Wereszczynski, A.

2012-02-01

We review the recently developed supersymmetric extensions of field theories with non-standard kinetic terms (so-called K field theories) in two an three dimensions. Further, we study the issue of topological defect formation in these supersymmetric theories. Specifically, we find supersymmetric K field theories which support topological kinks in 1+1 dimensions as well as supersymmetric extensions of the baby Skyrme model for arbitrary nonnegative potentials in 2+1 dimensions.

Local gauge coupling running in supersymmetric gauge theories on orbifolds

International Nuclear Information System (INIS)

Hillenbach, M.

2007-01-01

By extending Feynman's path integral calculus to fields which respect orbifold boundary conditions we provide a straightforward and convenient framework for loop calculations on orbifolds. We take advantage of this general method to investigate supersymmetric Abelian and non-Abelian gauge theories in five, six and ten dimensions where the extra dimensions are compactified on an orbifold. We consider hyper and gauge multiplets in the bulk and calculate the renormalization of the gauge kinetic term which in particular allows us to determine the gauge coupling running. The renormalization of the higher dimensional theories in orbifold spacetimes exhibits a rich structure with three principal effects: Besides the ordinary renormalization of the bulk gauge kinetic term the loop effects may require the introduction of both localized gauge kinetic terms at the fixed points/planes of the orbifold and higher dimensional operators. (orig.)

Neutron electric dipole moment from supersymmetric anomalous W-boson coupling

International Nuclear Information System (INIS)

Kadoyoshi, T.; Oshimo, N.

1997-01-01

In the supersymmetric standard model (SSM) the W boson could have a nonvanishing electric dipole moment (EDM) through a one-loop diagram mediated by the charginos and neutralinos. Then the W-boson EDM induces the EDMs of the neutron and the electron. We discuss these EDMs, taking into consideration the constraints from the neutron and electron EDMs at the one-loop level induced by the charginos and squarks or sleptons. It is shown that the neutron and the electron could, respectively, have EDMs of the order of 10 -26 ecm and 10 -27 ecm, solely owing to the W-boson EDM. Since these EDMs do not depend on the values of the SSM parameters for the squark or slepton sector, they provide less ambiguous predictions for CP violation in the SSM. copyright 1997 The American Physical Society

Local gauge coupling running in supersymmetric gauge theories on orbifolds

Energy Technology Data Exchange (ETDEWEB)

Hillenbach, M.

2007-11-21

By extending Feynman's path integral calculus to fields which respect orbifold boundary conditions we provide a straightforward and convenient framework for loop calculations on orbifolds. We take advantage of this general method to investigate supersymmetric Abelian and non-Abelian gauge theories in five, six and ten dimensions where the extra dimensions are compactified on an orbifold. We consider hyper and gauge multiplets in the bulk and calculate the renormalization of the gauge kinetic term which in particular allows us to determine the gauge coupling running. The renormalization of the higher dimensional theories in orbifold spacetimes exhibits a rich structure with three principal effects: Besides the ordinary renormalization of the bulk gauge kinetic term the loop effects may require the introduction of both localized gauge kinetic terms at the fixed points/planes of the orbifold and higher dimensional operators. (orig.)

Supersymmetric electroweak radiative corrections to e+e-→W+W-. III

International Nuclear Information System (INIS)

Alam, S.

1994-01-01

This is the third of a series of three papers in which we give a complete analysis of one loop quantum corrections to the W pair production in the context of supersymmetric electroweak theory. We adopt the on-shell-mass subtraction scheme of Sakakibara. In this paper we concentrate mainly on the one loop corrections to the differential cross section arising from the box diagrams. Details of the relevant analytic results are given. We also present our results for the total radiative corrections and wherever possible compare the QFD part of our calculation with previous work. We find a change of approximately 3%--4% in the differential cross section if the Higgs boson mass is varied from 10 GeV to 500 GeV. The differential cross section varies approximately 8% if the top mass is varied between 40 GeV and 150 GeV. Our results for the dependence of the differential cross section on the Higgs boson and top quark are in agreement with Bohm et al. In the context of the SM we find moderate corrections at CERN LEP II energies. We find the percentage (with respect to the tree-level) virtual loop corrections arising from the box diagrams (considered in this paper) due to the addition of SUSY particles varies approximately from 0.18% to -5.67%. As a comparison the percentage virtual corrections due to the box diagrams in the SM varies typically from 0.89% to 8.3%. The SM total percentage virtual loop corrections varies typically from 17.4% to 19%. The above comparison is made at the same center-of-mass energy (200 GeV). The first percentage in this comparison is for center-of-mass angles of 10 degree, the second being at 90 degree. Adding all the corrections up we find that the addition of the supersymmetric particles tends to increase the percentage one loop corrections on the order of 6%--8% provided the photino is kept light. With an accurate measurement at LEP II, one can in principle detect such a deviation away from the standard model

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.

Full colour for loop amplitudes in Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Ochirov, Alexander [Higgs Centre for Theoretical Physics, School of Physics and Astronomy,The University of Edinburgh,Edinburgh EH9 3JZ, Scotland (United Kingdom); Page, Ben [Albert-Ludwigs-Universität Freiburg, Physikalisches Institut,D-79104 Freiburg (Germany)

2017-02-20

We present a general method to account for full colour dependence Yang-Mills amplitudes at loop level. The method fits most naturally into the framework of multi-loop integrand reduction and in a nutshell amounts to consistently retaining the colour structures of the unitarity cuts from which the integrand is gradually constructed. This technique has already been used in the recent calculation of the two-loop five-gluon amplitude in pure Yang-Mills theory with all positive helicities, (DOI: 10.1007/JHEP10(2015)064). In this note, we give a careful exposition of the method and discuss its connection to loop-level Kleiss-Kuijf relations. We also explore its implications for cancellation of nontrivial symmetry factors at two loops. As an example of its generality, we show how it applies to the three-loop case in supersymmetric Yang-Mills case.

New supersymmetrizations of the generalized KDV hierarchies

International Nuclear Information System (INIS)

Figueroa-O'Farrill, J.M.; Stanciu, S.

1993-03-01

Recently we investigated a new supersymmetrization procedure for the KdV hierarchy inspired in some recent work on supersymmetric matrix models. We extend this procedure here for the generalized KdV hierarchies. The resulting supersymmetric hierarchies are generically nonlocal, expect for the case of Boussinesque which we treat in detail. The resulting supersymmetric hierarchy is integrable and bihamiltonian and contains the Boussinesque hierarchy as a subhierarchy. In a particular realization, we extend it by defining supersymmetric odd flows. We end with some comments on a slight modification of this supersymmetrization which yields local equations for any generalized KdV hierarchy. (orig.)

[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

Application of 't Hooft's renormalization scheme to two-loop calculations 230

International Nuclear Information System (INIS)

Vladimirov, A.A.

1975-01-01

The advantages of the Hooft scheme for asymptotic calculations in the renormalization group have been demonstrated. Two-loop calculations have been carried out in three renormalized models: in scalar electrodynamics, in a pseudoscalar Yukawa theory and in the Weiss-Zumino supersymmetrical model [ru

Supersymmetric quantum mechanics on n-dimensional manifolds

International Nuclear Information System (INIS)

O'Connor, M.

1990-01-01

In this thesis the author investigates the properties of the supersymmetric path integral on Riemannian manifolds. Chapter 1 is a brief introduction to supersymmetric path integral can be defined as the continuum limit of a discrete supersymmetric path integral. In Chapter 3 he shows that point canonical transformations in the path integral for ordinary quantum mechanics can be performed naively provided one uses the supersymmetric path integral. Chapter 4 generalizes the results of chapter 3 to include the propagation of all the fermion sectors in supersymmetric quantum mechanics. In Chapter 5 he shows how the properties of supersymmetric quantum mechanics can be used to investigate topological quantum mechanics

Two-loop calculation of the effective potential for the Wess-Zumino model

International Nuclear Information System (INIS)

Fogleman, G.; Starkmann, G.D.; Viswanathan, K.S.; Simon Fraser Univ., Burnaby, British Columbia

1983-01-01

The effective potential for the supersymmetric Wess-Zumino model is computed off-shell to two loops. A renormalization procedure which preserves positivity of the kinetic terms in the effective action is implemented. Supersymmetry is not broken to this order. (orig.)

Neutron electric dipole moment in the minimal supersymmetric standard model

International Nuclear Information System (INIS)

Inui, T.; Mimura, Y.; Sakai, N.; Sasaki, T.

1995-01-01

The neutron electric dipole moment (EDM) due to the single quark EDM and to the transition EDM is calculated in the minimal supersymmetric standard model. Assuming that the Cabibbo-Kobayashi-Maskawa matrix at the grand unification scale is the only source of CP violation, complex phases are induced in the parameters of soft supersymmetry breaking at low energies. The chargino one-loop diagram is found to give the dominant contribution of the order of 10 -27 similar 10 -29 e.cm for the quark EDM, assuming the light chargino mass and the universal scalar mass to be 50 GeV and 100 GeV, respectively. Therefore the neutron EDM in this class of model is difficult to measure experimentally. The gluino one-loop diagram also contributes due to the flavor changing gluino coupling. The transition EDM is found to give dominant contributions for certain parameter regions. (orig.)

New BCJ representations for one-loop amplitudes in gauge theories and gravity

Science.gov (United States)

He, Song; Schlotterer, Oliver; Zhang, Yong

2018-05-01

We explain a procedure to manifest the Bern-Carrasco-Johansson duality between color and kinematics in n-point one-loop amplitudes of a variety of supersymmetric gauge theories. Explicit amplitude representations are constructed through a systematic reorganization of the integrands in the Cachazo-He-Yuan formalism. Our construction holds for any nonzero number of supersymmetries and does not depend on the number of spacetime dimensions. The cancellations from supersymmetry multiplets in the loop as well as the resulting power counting of loop momenta is manifested along the lines of the corresponding superstring computations. The setup is used to derive the one-loop version of the Kawai-Lewellen-Tye formula for the loop integrands of gravitational amplitudes.

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.

Collisional processes in supersymmetric plasma

International Nuclear Information System (INIS)

Czajka, Alina; Mrowczynski, Stanislaw

2011-01-01

Collisional processes in ultrarelativistic N=1 supersymmetric QED plasma are studied and compared to those in an electromagnetic plasma of electrons, positrons and photons. Cross sections of all binary interactions which occur in the supersymmetric plasma at the order of e 4 are computed. Some processes, in particular, the Compton scattering on selectrons, appear to be independent of momentum transfer and thus they are qualitatively different from processes in an electromagnetic plasma. It suggests that the transport properties of the supersymmetric plasma are different than those of its nonsupersymmetric counterpart. Energy loss and momentum broadening of a particle traversing the supersymmetric plasma are discussed in detail and the characteristics are shown to be surprisingly similar to those of QED plasma.

One-loop divergences in 6D, N=(1,0) SYM theory

Energy Technology Data Exchange (ETDEWEB)

Buchbinder, I.L. [Department of Theoretical Physics, Tomsk State Pedagogical University,634061, Tomsk (Russian Federation); National Research Tomsk State University,634050, Tomsk (Russian Federation); Ivanov, E.A. [Bogoliubov Laboratory of Theoretical Physics,JINR, 141980 Dubna, Moscow region (Russian Federation); Merzlikin, B.S. [Department of Theoretical Physics, Tomsk State Pedagogical University,634061, Tomsk (Russian Federation); Department of Higher Mathematics and Mathematical Physics,Tomsk Polytechnic University,634050, Tomsk (Russian Federation); Stepanyantz, K.V. [Department of Theoretical Physics, Moscow State University,119991, Moscow (Russian Federation)

2017-01-30

We consider, in the harmonic superspace approach, the six-dimensional N=(1,0) supersymmetric Yang-Mills gauge multiplet minimally coupled to a hypermultiplet in an arbitrary representation of the gauge group. Using the superfield proper-time and background-field techniques, we compute the divergent part of the one-loop effective action depending on both the gauge multiplet and the hypermultiplet. We demonstrate that in the particular case of N=(1,1) SYM theory, which corresponds to the hypermultiplet in the adjoint representation, all one-loop divergencies vanish, so that N=(1,1) SYM theory is one-loop finite off shell.

Null polygonal Wilson loops and minimal surfaces in Anti-de-Sitter space

International Nuclear Information System (INIS)

Alday, Luis F.; Maldacena, Juan

2009-01-01

We consider minimal surfaces in three dimensional anti-de-Sitter space that end at the AdS boundary on a polygon given by a sequence of null segments. The problem can be reduced to a certain generalized Sinh-Gordon equation and to SU(2) Hitchin equations. We describe in detail the mathematical problem that needs to be solved. This problem is mathematically the same as the one studied by Gaiotto, Moore and Neitzke in the context of the moduli space of certain supersymmetric theories. Using their results we can find the explicit answer for the area of a surface that ends on an eight-sided polygon. Via the gauge/gravity duality this can also be interpreted as a certain eight-gluon scattering amplitude at strong coupling. In addition, we give fairly explicit solutions for regular polygons.

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.

One-loop Yukawa Couplings in Local Models

CERN Document Server

Conlon, Joseph P; Palti, Eran; 10.1007

2010-01-01

We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops.

One-loop Yukawa couplings in local models

International Nuclear Information System (INIS)

Conlon, Joseph P.; Goodsell, Mark; Palti, Eran

2010-07-01

We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops. (orig.)

One-loop Yukawa couplings in local models

Energy Technology Data Exchange (ETDEWEB)

Conlon, Joseph P. [Rudolf Peierls Center for Theoretical Physics, Oxford (United Kingdom); Balliol College, Oxford (United Kingdom); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Palti, Eran [Centre de Physique Theorique, Ecole Polytechnique, CNRS, Palaiseau (France)

2010-07-15

We calculate the one-loop Yukawa couplings and threshold corrections for supersymmetric local models of branes at singularities in type IIB string theory. We compute the corrections coming both from wavefunction and vertex renormalisation. The former comes in the IR from conventional field theory running and in the UV from threshold corrections that cause it to run from the winding scale associated to the full Calabi-Yau volume. The vertex correction is naively absent as it appears to correspond to superpotential renormalisation. However, we find that while the Wilsonian superpotential is not renormalised there is a physical vertex correction in the 1PI action associated to light particle loops. (orig.)

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.)

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

N ≥ 4 Supergravity Amplitudes from Gauge Theory at Two Loops

International Nuclear Information System (INIS)

Boucher-Veronneau, Camille

2012-01-01

We present the full two-loop four-graviton amplitudes in N = 4, 5, 6 supergravity. These results were obtained using the double-copy structure of gravity, which follows from the recently conjectured color-kinematics duality in gauge theory. The two-loop four-gluon scattering amplitudes in N = 0, 1, 2 supersymmetric gauge theory are a second essential ingredient. The gravity amplitudes have the expected infrared behavior: the two-loop divergences are given in terms of the squares of the corresponding one-loop amplitudes. The finite remainders are presented in a compact form. The finite remainder for N = 8 supergravity is also presented, in a form that utilizes a pure function with a very simple symbol.

Duality in supersymmetric Yang-Mills theory

International Nuclear Information System (INIS)

Peskin, M.E.

1997-02-01

These lectures provide an introduction to the behavior of strongly-coupled supersymmetric gauge theories. After a discussion of the effective Lagrangian in nonsupersymmetric and supersymmetric field theories, the author analyzes the qualitative behavior of the simplest illustrative models. These include supersymmetric QCD for N f c , in which the superpotential is generated nonperturbatively, N = 2 SU(2) Yang-Mills theory (the Seiberg-Witten model), in which the nonperturbative behavior of the effect coupling is described geometrically, and supersymmetric QCD for N f large, in which the theory illustrates a non-Abelian generalization of electric-magnetic duality. 75 refs., 12 figs

The massless limit of supersymmetric QCD

International Nuclear Information System (INIS)

Davis, A.C.; Dine, M.; Seiberg, N.

1983-01-01

We construct an effective lagrangian for supersymmetric QCD, using a simple set of rules. The model with non-zero quark mass, msub(q), has at least N supersymmetric vacua, where N is the number of colors (in agreement with Witten's index). These vacua move to infinity as msub(q)->0. We study the possibility of supersymmetric breaking at msub(q)=0. (orig.)

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

Duality in supersymmetric Yang-Mills theory

Energy Technology Data Exchange (ETDEWEB)

Peskin, M.E.

1997-02-01

These lectures provide an introduction to the behavior of strongly-coupled supersymmetric gauge theories. After a discussion of the effective Lagrangian in nonsupersymmetric and supersymmetric field theories, the author analyzes the qualitative behavior of the simplest illustrative models. These include supersymmetric QCD for N{sub f} < N{sub c}, in which the superpotential is generated nonperturbatively, N = 2 SU(2) Yang-Mills theory (the Seiberg-Witten model), in which the nonperturbative behavior of the effect coupling is described geometrically, and supersymmetric QCD for N{sub f} large, in which the theory illustrates a non-Abelian generalization of electric-magnetic duality. 75 refs., 12 figs.

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.

Higgs Boson Properties in the Standard Model and its Supersymmetric Extensions

CERN Document Server

Ellis, Jonathan Richard; Zwirner, F; Ellis, John; Ridolfi, Giovanni; Zwirner, Fabio

2007-01-01

We review the realization of the Brout-Englert-Higgs mechanism in the electroweak theory and describe the experimental and theoretical constraints on the mass of the single Higgs boson expected in the minimal Standard Model. We also discuss the couplings of this Higgs boson and its possible decay modes as functions of its unknown mass. We then review the structure of the Higgs sector in the minimal supersymmetric extension of the Standard Model (MSSM), noting the importance of loop corrections to the masses of its five physical Higgs bosons. Finally, we discuss some non-minimal models.

Higgs boson properties in the Standard Model and its supersymmetric extensions

International Nuclear Information System (INIS)

Ellis, J.; Ridolfi, G.; Zwirner, F.

2007-01-01

We review the realization of the Brout-Englert-Higgs mechanism in the electroweak theory and describe the experimental and theoretical constraints on the mass of the single Higgs boson expected in the minimal Standard Model. We also discuss the couplings of this Higgs boson and its possible decay modes as functions of its unknown mass. We then review the structure of the Higgs sector in the minimal supersymmetric extension of the Standard Model (MSSM), noting the importance of loop corrections to the masses of its 5 physical Higgs bosons. Finally, we discuss some non-minimal models. (authors)

Local integrand representations of all two-loop amplitudes in planar SYM

International Nuclear Information System (INIS)

Bourjaily, Jacob L.; Trnka, Jaroslav

2015-01-01

We use generalized unitarity at the integrand-level to directly construct local, manifestly dual-conformally invariant formulae for all two-loop scattering amplitudes in planar, maximally supersymmetric Yang-Mills theory (SYM). This representation separates contributions into manifestly finite and manifestly divergent terms — in a way that renders all infrared-safe observables (including ratio functions) calculable without any need for regulation. These results perfectly match the all-loop BCFW recursion relations, to which we provide a closed-form solution valid through two-loop-order. Finally, we describe and document a MATHEMATICA package which implements these results, available as part of this work’s source files on the arXiv.

On radiative gauge symmetry breaking in the minimal supersymmetric model

International Nuclear Information System (INIS)

Gamberini, G.; Ridolfi, G.; Zwirner, F.

1990-01-01

We present a critical reappraisal of radiative gauge symmetry breaking in the minimal supersymmetric standard model. We show that a naive use of the renormalization group improved tree-level potential can lead to incorrect conclusions. We specify the conditions under which the above method gives reliable results, by performing a comparison with the results obtained from the full one-loop potential. We also point out how the stability constraint and the conditions for the absence of charge- and colour-breaking minima should be applied. Finally, we comment on the uncertainties affecting the model predictions for physical observables, in particular for the top quark mass. (orig.)

One-loop polarization operator of the quantum gauge superfield for 𝒩 = 1 SYM regularized by higher derivatives

Science.gov (United States)

Kazantsev, A. E.; Skoptsov, M. B.; Stepanyantz, K. V.

2017-11-01

We consider the general 𝒩 = 1 supersymmetric gauge theory with matter, regularized by higher covariant derivatives without breaking the BRST invariance, in the massless limit. In the ξ-gauge we obtain the (unrenormalized) expression for the two-point Green function of the quantum gauge superfield in the one-loop approximation as a sum of integrals over the loop momentum. The result is presented as a sum of three parts: the first one corresponds to the pure supersymmetric Yang-Mills theory in the Feynman gauge, the second one contains all gauge-dependent terms, and the third one is the contribution of diagrams with a matter loop. For the Feynman gauge and a special choice of the higher derivative regulator in the gauge fixing term, we analytically calculate these integrals in the limit k → 0. In particular, in addition to the leading logarithmically divergent terms, which are determined by integrals of double total derivatives, we also find the finite constants.

Supersymmetric Quantum Mechanics and Topology

International Nuclear Information System (INIS)

Wasay, Muhammad Abdul

2016-01-01

Supersymmetric quantum mechanical models are computed by the path integral approach. In the β→0 limit, the integrals localize to the zero modes. This allows us to perform the index computations exactly because of supersymmetric localization, and we will show how the geometry of target space enters the physics of sigma models resulting in the relationship between the supersymmetric model and the geometry of the target space in the form of topological invariants. Explicit computation details are given for the Euler characteristics of the target manifold and the index of Dirac operator for the model on a spin manifold.

How to quantize supersymmetric theories

International Nuclear Information System (INIS)

Smilga, A.V.

1985-01-01

A recipe for resolving the ordering ambiguities in quantum hamiltonians of supersymmetric theories is suggested. The Weyl ordering procedure applied to classical supercharges expressed as functions on the phase space of a classically supersymmetric system is shown to result in quantum operators which satisfy usual SUSY algebra. The quantum hamiltonian does not always coincide with the Weyl ordered classical hamiltonian function. The difference is due to that the Weyl symbol of the supercharge anticommutator does not coincide with the Poisson bracket of their Weyl symbols (i.e. the classical hamiltonian). The procedure is applied to supersymmetric σ-models (both N=2 and N=1 cases are analyzed) and also to the supersymmetric SU(2) Yang-Mills theory. Only quantum mechanical systems following from field theories when fields are assumed to be independent of space coordinates are considered. For gauge theories thesuggested recipe for quantization leads to the same result as the well-known Dirac recipe

Supersymmetric two-particle equations

International Nuclear Information System (INIS)

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

1986-01-01

In the framework of the scalar superfield model, a particular case of which is the well-known Wess-Zumino model, the supersymmetric Schwinger equations are found. On their basis with the use of the second Legendre transformation the two-particle supersymmetric Edwards and Bethe-Salpeter equations are derived. A connection of the kernels and inhomogeneous terms of these equations with generating functional of the second Legendre transformation is found

Supersymmetric lattices

International Nuclear Information System (INIS)

Catterall, Simon

2013-01-01

Discretization of supersymmetric theories is an old problem in lattice field theory. It has resisted solution until quite recently when new ideas drawn from orbifold constructions and topological field theory have been brought to bear on the question. The result has been the creation of a new class of lattice gauge theory in which the lattice action is invariant under one or more supersymmetries. The resultant theories are local and free of doublers and in the case of Yang-Mills theories also possess exact gauge invariance. In principle they form the basis for a truly non-perturbative definition of the continuum supersymmetric field theory. In this talk these ideas are reviewed with particular emphasis being placed on N = 4 super Yang-Mills theory.

Non-supersymmetric orientifolds of Gepner models

Energy Technology Data Exchange (ETDEWEB)

Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); IMAPP, Radboud Universiteit, Nijmegen (Netherlands)], E-mail: t58@nikhef.nl

2009-01-12

Starting from a previously collected set of tachyon-free closed strings, we search for N=2 minimal model orientifold spectra which contain the standard model and are free of tachyons and tadpoles at lowest order. For each class of tachyon-free closed strings - bulk supersymmetry, automorphism invariants or Klein bottle projection - we do indeed find non-supersymmetric and tachyon free chiral brane configurations that contain the standard model. However, a tadpole-cancelling hidden sector could only be found in the case of bulk supersymmetry. Although about half of the examples we have found make use of branes that break the bulk space-time supersymmetry, the resulting massless open string spectra are nevertheless supersymmetric in all cases. Dropping the requirement that the standard model be contained in the spectrum, we find chiral tachyon and tadpole-free solutions in all three cases, although in the case of bulk supersymmetry all massless spectra are supersymmetric. In the other two cases we find truly non-supersymmetric spectra, but a large fraction of them are nevertheless partly or fully supersymmetric at the massless level.

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....

Exact Gell-Mann-Low function of supersymmetric Yang-Mills theories from instanton calculus

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.

1983-01-01

The instanton contribution to the vacuum energy is supersymmetric Yang-Mills theories is considered. Using renormalizability of the theory the exact beta function for n-extended supersymmetry (n=1, 2, 4) is found. The coefficients of the beta function have a geometrical meaning - they are associated with the number of boson and fermion zero modes in the instanton field. If extra matter superfields are added the method allows one to fix the first two coefficients. A non-renormalization theorem which extends cancellation of vacuum loops to the case of the external instanton field is proved

Chaos and random matrices in supersymmetric SYK

Science.gov (United States)

Hunter-Jones, Nicholas; Liu, Junyu

2018-05-01

We use random matrix theory to explore late-time chaos in supersymmetric quantum mechanical systems. Motivated by the recent study of supersymmetric SYK models and their random matrix classification, we consider the Wishart-Laguerre unitary ensemble and compute the spectral form factors and frame potentials to quantify chaos and randomness. Compared to the Gaussian ensembles, we observe the absence of a dip regime in the form factor and a slower approach to Haar-random dynamics. We find agreement between our random matrix analysis and predictions from the supersymmetric SYK model, and discuss the implications for supersymmetric chaotic systems.

Next-to-leading order strong interaction corrections to the ΔF = 2 effective Hamiltonian in the MSSM

International Nuclear Information System (INIS)

Ciuchini, Marco; Franco, E.; Guadagnoli, D.; Lubicz, Vittorio; Porretti, V.; Silvestrini, L.

2006-01-01

We compute the next-to-leading order strong interaction corrections to gluino-mediated ΔF = 2 box diagrams in the Minimal Supersymmetric Standard Model. These corrections are given by two loop diagrams which we have calculated in three different regularization schemes in the mass insertion approximation. We obtain the next-to-leading order Wilson coefficients of the ΔF = 2 effective Hamiltonian relevant for neutral meson mixings. We find that the matching scale uncertainty is largely reduced at the next-to-leading order, typically from about 10-15% to few percent

Analysis of the production of Higgs boson pairs at the one-loop level in the minimal supersymmetric standard model

International Nuclear Information System (INIS)

Philippov, Yu. P.

2009-01-01

Within the minimal supersymmetric standard model, the amplitudes and total cross sections for the processes e + e - → hh, e + e - → hH, e + e - → HH, and e + e - → AA are calculated in the first order of perturbation theory with allowance for a complete set of one-loop diagrams in the m e → 0 approximation. Analytic expressions are obtained for the quantities under consideration; numerical results are presented in a graphical form. It is shown that the cross section for the process e + e - → hh is larger than those for the other processes (and is on the same order of magnitude as the cross section for the corresponding processes in the Standard Model). In the case of the collision energy equal to √s = 500 GeV, an integrated luminosity in the region ∫ L ≥ 500 fb -1 , and a longitudinal polarization of the e + e- beams used, 520, 320, and 300 production events are possible in the processes e + e - → hh (at M h = 115 GeV), e + e - → HH, and e + e - → AA (at M H,A = 120 GeV), respectively. Even at M H,A ∼ 500 GeV and √s = 1.5 TeV, not less than 200 events for each of the processes can be accumulated. The cross section for the process e + e - → hH is small (about 10 -2 fb), which complicates the detection of the sought signal significantly.

Loop amplitudes in an extended gravity theory

Science.gov (United States)

Dunbar, David C.; Godwin, John H.; Jehu, Guy R.; Perkins, Warren B.

2018-05-01

We extend the S-matrix of gravity by the addition of the minimal three-point amplitude or equivalently adding R3 terms to the Lagrangian. We demonstrate how Unitarity can be used to simply examine the renormalisability of this theory and determine the R4 counter-terms that arise at one-loop. We find that the combination of R4 terms that arise in the extended theory is complementary to the R4 counter-term associated with supersymmetric Lagrangians.

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.

Subtleties in the beta-function calculation of N = 1 supersymmetric gauge theories

Energy Technology Data Exchange (ETDEWEB)

Cherchiglia, A.L. [ICEx, Universidade Federal de Minas Gerais, Departamento de Fisica, P.O. Box 702, Belo Horizonte, MG (Brazil); Universidad de Granada, Departamento de Fisica Teorica y del Cosmos and CAFPE, Granada (Spain); Sampaio, Marcos [ICEx, Universidade Federal de Minas Gerais, Departamento de Fisica, P.O. Box 702, Belo Horizonte, MG (Brazil); Hiller, B. [CFisUC, Universidade de Coimbra, Departamento de Fisica, Faculdade de Ciencias e Tecnologia, Coimbra (Portugal); Scarpelli, A.P.B. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Sao Paulo (Brazil)

2016-02-15

We investigate some peculiarities in the calculation of the two-loop beta function of N = 1 supersymmetric models which are intimately related to the so-called ''anomaly puzzle''. There is an apparent paradox when the computation is performed in the framework of the covariant derivative background field method. In this formalism, there is obtained a finite two-loop effective action, although a non-null coefficient for the beta function is achieved by means of the renormalized two-point function in the background field. We show that if the standard background field method is used, this two-point function has a divergent part which allows for the calculation of the beta function via the renormalization constants, as usual. Therefore, we conjecture that this paradox has its origin in the covariant supergraph formalism itself, possibly being an artifact of the rescaling anomaly. (orig.)

Subtleties in the beta-function calculation of N = 1 supersymmetric gauge theories

International Nuclear Information System (INIS)

Cherchiglia, A.L.; Sampaio, Marcos; Hiller, B.; Scarpelli, A.P.B.

2016-01-01

We investigate some peculiarities in the calculation of the two-loop beta function of N = 1 supersymmetric models which are intimately related to the so-called ''anomaly puzzle''. There is an apparent paradox when the computation is performed in the framework of the covariant derivative background field method. In this formalism, there is obtained a finite two-loop effective action, although a non-null coefficient for the beta function is achieved by means of the renormalized two-point function in the background field. We show that if the standard background field method is used, this two-point function has a divergent part which allows for the calculation of the beta function via the renormalization constants, as usual. Therefore, we conjecture that this paradox has its origin in the covariant supergraph formalism itself, possibly being an artifact of the rescaling anomaly. (orig.)

The Effective Prepotential of N=2 Supersymmetric $SU(N_c)$ Gauge Theories

CERN Document Server

D'Hoker, Eric; Phong, D.H.; D'Hoker, Eric

1996-01-01

We determine the effective prepotential for N=2 supersymmetric SU(N_c) gauge theories with an arbitrary number of flavors N_f < 2N_c, from the exact solution constructed out of spectral curves. The prepotential is the same for the several models of spectral curves proposed in the literature. It has to all orders the logarithmic singularities of the one-loop perturbative corrections, thus confirming the non-renormalization theorems from supersymmetry. In particular, the renormalized order parameters and their duals have all the correct monodromy transformations prescribed at weak coupling. We evaluate explicitly the contributions of one- and two-instanton processes.

Electric dipole moments from Yukawa phases in supersymmetric theories

International Nuclear Information System (INIS)

Romanino, A.; Strumia, A.

1997-01-01

We study quark and electron EDMs generated by Yukawa couplings in supersymmetric models with different gauge groups, using the EDM properties under flavour transformations. In the MSSM (or if soft terms are mediated below the unification scale) the one-loop contributions to the neutron EDM are smaller than in previous computations based on numerical methods, although increasing as tan 3 β. A neutron EDM close to the experimental limits can be generated in SU(5), if tan β is large, through the u-quark EDM d u , proportional to tan 4 β. This effect has to be taken into account also in SO(10) with large tan β, where d u is comparable to the d quark EDM, proportional to tan β. (orig.)

The supersymmetric Pegg-Barnett oscillator

International Nuclear Information System (INIS)

Shen, Jian Qi

2005-01-01

The su(n) Lie algebraic structure of the Pegg-Barnett oscillator that possesses a finite-dimensional number-state space is demonstrated. The supersymmetric generalization of the Pegg-Barnett oscillator is suggested. it is shown that such a supersymmetric Pegg-Barnett oscillator may have some potential applications, e.g., the mass spectrum of the charged leptons

Ultraviolet divergences in non-renormalizable supersymmetric theories

International Nuclear Information System (INIS)

Smilga, A.

2017-01-01

We present a pedagogical review of our current understanding of the ultraviolet structure of N =(1, 1) 6D supersymmetric Yang-Mills theory and of N = 8 4D supergravity. These theories are not renormalizable, they involve power ultraviolet divergences and, in all probability, an infinite set of higher-dimensional counterterms that contribute to on-mass-shell scattering amplitudes. A specific feature of supersymmetric theories (especially of extended supersymmetric theories) is that these counterterms may not be invariant off-shell under the full set of supersymmetry transformations. The lowest-dimensional nontrivial counterterm is supersymmetric on-shell. Still higher counterterms may lose even the on-shell invariance. On the other hand, the full effective Lagrangian, generating the amplitudes and representing an infinite sum of counterterms, still enjoys the complete symmetry of original theory. We also discuss simple supersymmetric quantum-mechanical models that exhibit the same behavior.

Monopoles and instantons on partially compactified D-branes

International Nuclear Information System (INIS)

Lee, K.; Yi, P.

1997-01-01

Motivated by the recent D-brane constructions of world-volume monopoles and instantons, we study the supersymmetric SU(N) Yang-Mills theory on S 1 xR 3+1 , spontaneously broken by a Wilson loop. In addition to the usual N-1 fundamental monopoles, the Nth Bogomol close-quote nyi-Prasad-Sommerfield monopole appears from the Kaluza-Klein sector. When all N monopoles are present, net magnetic charge vanishes and the solution can be reinterpreted as a Wilson-loop instanton of unit Pontryagin number. The instanton-multimonopole moduli space is explicitly constructed, and seen to be identical to a Coulomb phase moduli space of a U(1) N gauge theory in 2+1 dimensions related to Kronheimer close-quote s gauge theory of SU(N)-type. This extends the results by Intriligator and Seiberg to the finite couplings that, in the infrared limit of Kronheimer close-quote s theory, the Coulomb phase parametrizes a centered SU(N) instanton. We also elaborate on the case of restored SU(N) symmetry. copyright 1997 The American Physical Society

Renormalization of supersymmetric theories

International Nuclear Information System (INIS)

Pierce, D.M.

1998-06-01

The author reviews the renormalization of the electroweak sector of the standard model. The derivation also applies to the minimal supersymmetric standard model. He discusses regularization, and the relation between the threshold corrections and the renormalization group equations. He considers the corrections to many precision observables, including M W and sin 2 θ eff . He shows that global fits to the data exclude regions of supersymmetric model parameter space and lead to lower bounds on superpartner masses

Supersymmetric gauge field theories

International Nuclear Information System (INIS)

Slavnov, A.A.

1976-01-01

The paper is dealing with the role of supersymmetric gauge theories in the quantum field theory. Methods of manipulating the theories as well as possibilities of their application in elementary particle physics are presented. In particular, the necessity is explained of a theory in which there is symmetry between Fermi and Bose fields, in other words, of the supersymmetric gauge theory for construction of a scheme for the Higgs particle connecting parameters of scalar mesons with those of the rest fields. The mechanism of supersymmetry breaking is discussed which makes it possible to remain the symmetric procedure of renormalization intact. The above mechanism of spontaneous symmetry breaking is applied to demonstrate possibilities of constructing models of weak and electromagnetic interactions which would be acceptable from the point of view of experiments. It is noted that the supersymmetric gauge theories represent a natural technique for description of vector-like models

Bubbles of nothing and supersymmetric compactifications

Energy Technology Data Exchange (ETDEWEB)

Blanco-Pillado, Jose J. [IKERBASQUE, Basque Foundation for Science, 48011, Bilbao (Spain); Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain); Shlaer, Benjamin [Department of Physics, University of Auckland,Private Bag 92019, Auckland (New Zealand); Institute of Cosmology, Department of Physics and Astronomy,Tufts University, Medford, MA 02155 (United States); Sousa, Kepa [Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain); Instituto de Fisica Teorica UAM-CSIC, Universidad Autonoma de Madrid,Cantoblanco, 28049 Madrid (Spain); Urrestilla, Jon [Department of Theoretical Physics, University of the Basque Country UPV/EHU,48080 Bilbao (Spain)

2016-10-03

We investigate the non-perturbative stability of supersymmetric compactifications with respect to decay via a bubble of nothing. We show examples where this kind of instability is not prohibited by the spin structure, i.e., periodicity of fermions about the extra dimension. However, such “topologically unobstructed” cases do exhibit an extra-dimensional analog of the well-known Coleman-De Luccia suppression mechanism, which prohibits the decay of supersymmetric vacua. We demonstrate this explicitly in a four dimensional Abelian-Higgs toy model coupled to supergravity. The compactification of this model to M{sub 3}×S{sub 1} presents the possibility of vacua with different windings for the scalar field. Away from the supersymmetric limit, these states decay by the formation of a bubble of nothing, dressed with an Abelian-Higgs vortex. We show how, as one approaches the supersymmetric limit, the circumference of the topologically unobstructed bubble becomes infinite, thereby preventing the realization of this decay. This demonstrates the dynamical origin of the decay suppression, as opposed to the more familiar argument based on the spin structure. We conjecture that this is a generic mechanism that enforces stability of any topologically unobstructed supersymmetric compactification.

One-loop triple collinear splitting amplitudes in QCD

Energy Technology Data Exchange (ETDEWEB)

Badger, Simon; Buciuni, Francesco; Peraro, Tiziano [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, University of Edinburgh,Edinburgh EH9 3JZ, Scotland (United Kingdom)

2015-09-28

We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic Higgs plus four partons amplitudes. We present compact results for primitive helicity splitting amplitudes making use of super-symmetric decompositions. The universality of the collinear factorisation is checked numerically against the full colour six parton squared matrix elements.

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.)

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)

Classification of supersymmetric backgrounds of string theory

International Nuclear Information System (INIS)

Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

2007-01-01

We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to nearly maximally supersymmetric backgrounds. We then demonstrate its effectiveness by classifying the maximally supersymmetric IIB G-backgrounds and by showing that N=31 IIB solutions do not exist. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Non-renormalization theorems andN=2 supersymmetric backgrounds

International Nuclear Information System (INIS)

Butter, Daniel; Wit, Bernard de; Lodato, Ivano

2014-01-01

The conditions for fully supersymmetric backgrounds of general N = 2 locally supersymmetric theories are derived based on the off-shell superconformal multiplet calculus. This enables the derivation of a non-renormalization theorem for a large class of supersymmetric invariants with higher-derivative couplings. The theorem implies that the invariant and its first order variation must vanish in a fully supersymmetric background. The conjectured relation of one particular higher-derivative invariant with a specific five-dimensional invariant containing the mixed gauge-gravitational Chern-Simons term is confirmed

Supersymmetric flaxion

Science.gov (United States)

Ema, Yohei; Hagihara, Daisuke; Hamaguchi, Koichi; Moroi, Takeo; Nakayama, Kazunori

2018-04-01

Recently, a new minimal extension of the Standard Model has been proposed, where a spontaneously broken, flavor-dependent global U(1) symmetry is introduced. It not only explains the hierarchical flavor structure in the quark and lepton sector, but also solves the strong CP problem by identifying the Nambu-Goldstone boson as the QCD axion, which we call flaxion. In this work, we consider supersymmetric extensions of the flaxion scenario. We study the CP and flavor violations due to supersymmetric particles, the effects of R-parity violations, the cosmological gravitino and axino problems, and the cosmological evolution of the scalar partner of the flaxion, sflaxion. We also propose an attractor-like inflationary model where the flaxion multiplet contains the inflaton field, and show that a consistent cosmological scenario can be obtained, including inflation, leptogenesis, and dark matter.

Lattice formulations of supersymmetric gauge theories with matter fields

International Nuclear Information System (INIS)

Joseph, Anosh

2014-12-01

Certain classes of supersymmetric gauge theories, including the well known N=4 supersymmetric Yang-Mills theory, that takes part in the AdS/CFT correspondence, can be formulated on a Euclidean spacetime lattice using the techniques of exact lattice supersymmetry. Great ideas such as topological field theories, Dirac-Kaehler fermions, geometric discretization all come together to create supersymmetric lattice theories that are gauge-invariant, doubler free, local and exact supersymmetric. We discuss the recent lattice constructions of supersymmetric Yang-Mills theories in two and three dimensions coupled to matter fields in various representations of the color group.

Webs of domain walls in supersymmetric gauge theories

International Nuclear Information System (INIS)

Eto, Minoru; Isozumi, Youichi; Nitta, Muneto; Ohashi, Keisuke; Sakai, Norisuke

2005-01-01

Webs of domain walls are constructed as 1/4 Bogomol'nyi-Prasad-Sommerfield (BPS) states in d=4, N=2 supersymmetric U(N C ) gauge theories with N F hypermultiplets in the fundamental representation. Webs of walls can contain any numbers of external legs and loops like (p,q) string/5-brane webs. We find the moduli space M of a 1/4 BPS equation for wall webs to be the complex Grassmann manifold. When moduli spaces of 1/2 BPS states (parallel walls) and the vacua are removed from M, the noncompact moduli space of genuine 1/4 BPS wall webs is obtained. All the solutions are obtained explicitly and exactly in the strong gauge coupling limit. In the case of Abelian gauge theory, we work out the correspondence between configurations of wall web and the moduli space CP N F -1

Refined 3d-3d correspondence

Energy Technology Data Exchange (ETDEWEB)

Alday, Luis F.; Genolini, Pietro Benetti; Bullimore, Mathew; Loon, Mark van [Mathematical Institute, University of Oxford, Andrew Wiles Building,Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG (United Kingdom)

2017-04-28

We explore aspects of the correspondence between Seifert 3-manifolds and 3d N=2 supersymmetric theories with a distinguished abelian flavour symmetry. We give a prescription for computing the squashed three-sphere partition functions of such 3d N=2 theories constructed from boundary conditions and interfaces in a 4d N=2{sup ∗} theory, mirroring the construction of Seifert manifold invariants via Dehn surgery. This is extended to include links in the Seifert manifold by the insertion of supersymmetric Wilson-’t Hooft loops in the 4d N=2{sup ∗} theory. In the presence of a mass parameter for the distinguished flavour symmetry, we recover aspects of refined Chern-Simons theory with complex gauge group, and in particular construct an analytic continuation of the S-matrix of refined Chern-Simons theory.

Two-Loop Correction to the Higgs Boson Mass in the MRSSM

International Nuclear Information System (INIS)

Stöckinger, Dominik; Diessner, Philip; Kotlarski, Wojciech; Kalinowski, Jan

2015-01-01

We present the impact of two-loop corrections on the mass of the lightest Higgs boson in the minimal R-symmetric supersymmetric standard model (MRSSM). These shift the Higgs boson mass up by typically 5 GeV or more. The dominant corrections arise from strong interactions, and from the gluon and its N=2 superpartners, the sgluon and Dirac gluino, and these corrections further increase with large Dirac gluino mass. The two-loop contributions governed purely by Yukawa couplings and the MRSSM λ, Λ parameters are smaller. We also update our earlier analysis which showed that the MRSSM can accommodate the measured Higgs and W boson masses. Including the two-loop corrections increases the parameter space where the theory prediction agrees with the measurement.

Exact Gell-Mann-Low function of supersymmetric Yang-Mills theories from instanton calculus

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vainshtein, A.I.; Zakharov, V.I.

1983-01-01

The instanton contribution to the vacuum energy in supersymmetric Yang-Mills theories is considered. Using the renormalizability of the theory we find the exact beta function for n-extended supersymmetry (n=1, 2, 4). The coefficients of the beta function have a geometrical meaning: they are associated with the number of boson and fermion zero modes in the instanton field. If extra matter superfields are added our method allows one to fix the first two coefficients. We prove a non-renormalization theorem which extends the cancellation of vacuum loops to the case of the external instanton field. (orig.)

Higher Loop Corrections to the Infrared Evolution of Fermionic Gauge Theories in the RI' Scheme

DEFF Research Database (Denmark)

Ryttov, Thomas

2014-01-01

We study the evolution of the gauge coupling and the anomalous dimension of the mass towards an infrared fixed point for non-supersymmetric gauge theories in the modified regularization invariant, RI', scheme. This is done at the three loop level where all the renormalization group functions have...

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

Supersymmetric and non-supersymmetric Seiberg-like dualities for gauged Wess–Zumino–Witten theories, realised on branes

Directory of Open Access Journals (Sweden)

E. Ireson

2016-01-01

Full Text Available In this work we extend the results of previous derivations of Seiberg-like dualities (level-rank duality between gauged Wess–Zumino–Witten theories. The arguments in use to identify a potential dual for the supersymmetric WZW theory based on the coset U(N+MkU(Nk can be extended to be applied to a wider variety of gauge groups, notably USp(2N+2M2kUSp(2N2k and SO(2N+2M2kSO(2N2k, which will be dealt with briefly. Most interestingly, non-supersymmetric versions of the latter theories can also be shown to have duals in a similar fashion. These results are supported by several pieces of evidence, string phenomenological interpretations of Seiberg duality, even in non-supersymmetric backgrounds, are helpful to justify the formulation, then, from field theory, quantities such as central charges or Witten indices are shown to match exactly. The stability of these non-supersymmetric models is also discussed and shown to be consistent.

Supersymmetric technicolor

International Nuclear Information System (INIS)

Srednicki, M.

1981-01-01

I will discuss some work I recently completed with M. Dine and W. Fischler on supersymmetric technicolor. E. Witten and S. Dimopoulos and S. Raby have considered similar ideas. Our central idea is to combine supersymmetry and technicolor to produce a natural theory which is capable of reproducing all the known phenomenology of particle physics, especially the quark-lepton mass spectrum and the absence of flavor changing neutral currents. Supersymmetry allows us to introduce fundamental scalars which are naturally light. Some of these scalars play the role of Higgs fields, and give mass to quarks and leptons via ordinary Yukawa couplings (which are chosen so that we get the correct masses and mixing angles). The supersymmetric partners of all known particles turn out to be too heavy to have been observed in experiments to data; many of them, however, weigh less than 100 GeV

Analysis of Ward identities in supersymmetric Yang-Mills theory

Science.gov (United States)

Ali, Sajid; Bergner, Georg; Gerber, Henning; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp

2018-05-01

In numerical investigations of supersymmetric Yang-Mills theory on a lattice, the supersymmetric Ward identities are valuable for finding the critical value of the hopping parameter and for examining the size of supersymmetry breaking by the lattice discretisation. In this article we present an improved method for the numerical analysis of supersymmetric Ward identities, which takes into account the correlations between the various observables involved. We present the first complete analysis of supersymmetric Ward identities in N=1 supersymmetric Yang-Mills theory with gauge group SU(3). The results indicate that lattice artefacts scale to zero as O(a^2) towards the continuum limit in agreement with theoretical expectations.

Effective field theory for magnetic compactifications

Energy Technology Data Exchange (ETDEWEB)

Buchmuller, Wilfried; Dierigl, Markus [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany); Dudas, Emilian [Centre de Physique Théorique, École Polytechnique, CNRS, Université Paris-Saclay,F-91128 Palaiseau (France); Schweizer, Julian [Deutsches Elektronen-Synchrotron DESY,22607 Hamburg (Germany)

2017-04-10

Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective action for N=1 supersymmetric Abelian and non-Abelian gauge theories in six dimensions compactified on a torus with flux. The effective action contains the tower of charged states and it accounts for the mass spectrum of bosonic and fermionic fields as well as their level-dependent interactions. This allows us to compute quantum corrections to the mass and couplings of Wilson lines. We find that the one-loop corrections vanish, contrary to the case without flux. This can be traced back to the spontaneous breaking of symmetries of the six-dimensional theory by the background gauge field, with the Wilson lines as Goldstone bosons.

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

Additional symmetries of supersymmetric KP hierarchies

International Nuclear Information System (INIS)

Stanciu, S.

1993-09-01

We investigate the additional symmetries of several supersymmetric KP hierarchies: The SKP hierarchy of Manin and Radul, the SKP 2 hierarchy, and the Jacobian SKP hierarchy. The main technical tool is the supersymmetric generalisation of a map originally due to Radul between the Lie algebra of superdifferential operators and the Lie algebra of vector fields on the space of supersymmetric Lax operators. In the case of the Manin-Radul SKP hierarchy we identify additional symmetries which form an algebra isomorphic to a subalgebra of superdifferential operators; whereas in the case of the Jacobian SKP, the (additional) symmetries are identified with the algebra itself. (orig.)

Search for a Supersymmetric Partner to the Top Quark using a Multivariate Analysis Technique.

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00337045

Supersymmetry (SUSY) is an extension to the Standard Model (SM) which introduces supersymmetric partners of the known fermions and bosons. Top squark (stop) searches are a natural extension of inclusive SUSY searches at the Large Hadron Collider (LHC). If SUSY solves the naturalness problem, the stop should be light enough to cancel the top loop contribution to the Higgs mass parameter. The 3rd generation squarks may be the first SUSY particles to be discovered at the LHC. The stop can decay into a variety of final states, depending, amongst other factors, on the hierarchy of the mass eigenstates formed from the linear superposition of the SUSY partners of the Higgs boson and electroweak gauge bosons. In this study the relevant mass eigenstates are the lightest chargino ($\\chi_{1}^{\\pm}$) and the neutralino ($\\chi_{1}^{0}$). A search is presented for a heavy SUSY top partner decaying to a lepton, neutrino and the lightest supersymmetric particle ($\\chi_{1}^{0}$), via a b-quark and a chargino ($\\chi_{1}^{\\p...

Higgs amplitudes from supersymmetric form factors Part I: $\\mathcal{N}=4$ super Yang-Mills arXiv

CERN Document Server

Brandhuber, Andreas; Penante, Brenda; Travaglini, Gabriele

In the large top-mass limit, Higgs plus multi-gluon amplitudes in QCD can be computed using an effective field theory. This approach turns the computation of such amplitudes into that of form factors of operators of increasing classical dimension. In this paper we focus on the first finite top-mass correction, arising from the operator ${\\rm Tr}(F^3)$, up to two loops and three gluons. Setting up the calculation in the maximally supersymmetric theory requires identification of an appropriate supersymmetric completion of ${\\rm Tr}(F^3)$, which we recognise as a descendant of the Konishi operator. We provide detailed computations for both this operator and the component operator ${\\rm Tr}(F^3)$, preparing the ground for the calculation in $\\mathcal{N}<4$, to be detailed in a companion paper. Our results for both operators are expressed in terms of a few universal functions of transcendental degree four and below, some of which have appeared in other contexts, hinting at universality of such quantities. An im...

Supersymmetric probes on the conifold

International Nuclear Information System (INIS)

Arean, Daniel; Crooks, David E.; Ramallo, Alfonso V.

2004-01-01

We study the supersymmetric embeddings of different D-brane probes in the AdS 5 xT 1,1 geometry. The main tool employed is kappa symmetry and the cases studied include D3-, D5- and D7-branes. We find a family of three-cycles of the T 1,1 space over which a D3-brane can be wrapped supersymmetrically and we determine the field content of the corresponding gauge theory duals. Supersymmetric configurations of D5-branes wrapping a two-cycle and of spacetime filling D7-branes are also found. The configurations in which the entire T 1,1 space is wrapped by a D5-brane (baryon vertex) and a D7-brane are also studied. Some other embeddings which break supersymmetry but are nevertheless stable are also determined. (author)

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.

String states, loops and effective actions in noncommutative field theory and matrix models

Directory of Open Access Journals (Sweden)

Harold C. Steinacker

2016-09-01

Full Text Available Refining previous work by Iso, Kawai and Kitazawa, we discuss bi-local string states as a tool for loop computations in noncommutative field theory and matrix models. Defined in terms of coherent states, they exhibit the stringy features of noncommutative field theory. This leads to a closed form for the 1-loop effective action in position space, capturing the long-range non-local UV/IR mixing for scalar fields. The formalism applies to generic fuzzy spaces. The non-locality is tamed in the maximally supersymmetric IKKT or IIB model, where it gives rise to supergravity. The linearized supergravity interactions are obtained directly in position space at one loop using string states on generic noncommutative branes.

String states, loops and effective actions in noncommutative field theory and matrix models

Energy Technology Data Exchange (ETDEWEB)

Steinacker, Harold C., E-mail: harold.steinacker@univie.ac.at

2016-09-15

Refining previous work by Iso, Kawai and Kitazawa, we discuss bi-local string states as a tool for loop computations in noncommutative field theory and matrix models. Defined in terms of coherent states, they exhibit the stringy features of noncommutative field theory. This leads to a closed form for the 1-loop effective action in position space, capturing the long-range non-local UV/IR mixing for scalar fields. The formalism applies to generic fuzzy spaces. The non-locality is tamed in the maximally supersymmetric IKKT or IIB model, where it gives rise to supergravity. The linearized supergravity interactions are obtained directly in position space at one loop using string states on generic noncommutative branes.

Two-loop finiteness of self-energies in higher-derivative SQED3

Directory of Open Access Journals (Sweden)

E.A. Gallegos

2015-09-01

Full Text Available In the N=1 superfield formalism, two higher-derivative kinetic operators (Lee–Wick operators are implemented into the standard three dimensional supersymmetric quantum electrodynamics (SQED3 for improving its ultraviolet behavior. It is shown in particular that the ghosts associated with these Lee–Wick operators allow to remove all ultraviolet divergences in the scalar and gauge self-energies at two-loop level.

A supersymmetric Skyrme model

International Nuclear Information System (INIS)

Gudnason, Sven Bjarke; Nitta, Muneto; Sasaki, Shin

2016-01-01

Construction of a supersymmetric extension of the Skyrme term was a long-standing problem because of the auxiliary field problem; that is, the auxiliary field may propagate and cannot be eliminated, and the problem of having fourth-order time derivative terms. In this paper, we construct for the first time a supersymmetric extension of the Skyrme term in four spacetime dimensions, in the manifestly supersymmetric superfield formalism that does not suffer from the auxiliary field problem. Chiral symmetry breaking in supersymmetric theories results not only in Nambu-Goldstone (NG) bosons (pions) but also in the same number of quasi-NG bosons so that the low-energy theory is described by an SL(N,ℂ)-valued matrix field instead of SU(N) for NG bosons. The solution of auxiliary fields is trivial on the canonical branch of the auxiliary field equation, in which case our model results in a fourth-order derivative term that is not the Skyrme term. For the case of SL(2,ℂ), we find explicitly a nontrivial solution to the algebraic auxiliary field equations that we call a non-canonical branch, which when substituted back into the Lagrangian gives a Skyrme-like model. If we restrict to a submanifold, where quasi-NG bosons are turned off, which is tantamount to restricting the Skyrme field to SU(2), then the fourth-order derivative term reduces exactly to the standard Skyrme term. Our model is the first example of a nontrivial auxiliary field solution in a multi-component model.

The particle interpretation of N = 1 supersymmetric spin foams

Energy Technology Data Exchange (ETDEWEB)

Baccetti, Valentina [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma (Italy); Livine, Etera R [Laboratoire de Physique, ENS Lyon, CNRS UMR 5672, 46 Allee d' Italie, 69007 Lyon (France); Ryan, James P, E-mail: baccetti@neve.fis.uniroma3.i, E-mail: etera.livine@ens-lyon.f, E-mail: james.ryan@aei.mpg.d [MPI fuer Gravitationsphysik, Albert Einstein Institute, Am Muehlenberg 1, D-14476 Potsdam (Germany)

2010-11-21

We show that N = 1-supersymmetric BF theory in 3D leads to a supersymmetric spin foam amplitude via a lattice discretization. Furthermore, by analysing the supersymmetric quantum amplitudes, we show that they can be re-interpreted as 3D gravity coupled to embedded fermionic Feynman diagrams.

The particle interpretation of N = 1 supersymmetric spin foams

International Nuclear Information System (INIS)

Baccetti, Valentina; Livine, Etera R; Ryan, James P

2010-01-01

We show that N = 1-supersymmetric BF theory in 3D leads to a supersymmetric spin foam amplitude via a lattice discretization. Furthermore, by analysing the supersymmetric quantum amplitudes, we show that they can be re-interpreted as 3D gravity coupled to embedded fermionic Feynman diagrams.

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

On the supersymmetric solitons and monopoles

International Nuclear Information System (INIS)

Hruby, J.

1978-01-01

The basic results in a new trend in supersymmetry and soliton theory are presented. It is shown that the soliton expectation value of the energy operator is mass of the soliton without the quantum corrections. A new supersymmetric monopole model in three dimensions is constructed by generalization of the supersymmetric sine-Gordon model in one space dimension

Supersymmetric models and their phenomenology

International Nuclear Information System (INIS)

Ross, G.G.

1995-01-01

The prospects for unification of the Standard Model are considered and the need for supersymmetry discussed. The prediction of the gauge couplings, the electroweak breaking scale, the fermion masses and the dark matter abundance are all consistent with simple unification if there is a stage of supersymmetric unification below the TeV scale. The prospects for discovery of the new SUSY states is considered, both in the minimal supersymmetric standard model and in non-minimal extensions. (author)

Supersymmetric sigma models

International Nuclear Information System (INIS)

Bagger, J.A.

1984-09-01

We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model

Supersymmetric sigma models

Energy Technology Data Exchange (ETDEWEB)

Bagger, J.A.

1984-09-01

We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model.

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.)

Classification of supersymmetric backgrounds of string theory

NARCIS (Netherlands)

Gran, Ulf; Gutowski, Jan; Papadopoulos, George; Roest, Diederik

2007-01-01

We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to nearly maximally supersymmetric backgrounds.We then demonstrate

Patterns of flavor signals in supersymmetric models

Energy Technology Data Exchange (ETDEWEB)

Goto, T. [KEK National High Energy Physics, Tsukuba (Japan)]|[Kyoto Univ. (Japan). YITP; Okada, Y. [KEK National High Energy Physics, Tsukuba (Japan)]|[Graduate Univ. for Advanced Studies, Tsukuba (Japan). Dept. of Particle and Nucelar Physics; Shindou, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[International School for Advanced Studies, Trieste (Italy); Tanaka, M. [Osaka Univ., Toyonaka (Japan). Dept. of Physics

2007-11-15

Quark and lepton flavor signals are studied in four supersymmetric models, namely the minimal supergravity model, the minimal supersymmetric standard model with right-handed neutrinos, SU(5) supersymmetric grand unified theory with right-handed neutrinos and the minimal supersymmetric standard model with U(2) flavor symmetry. We calculate b{yields}s(d) transition observables in B{sub d} and B{sub s} decays, taking the constraint from the B{sub s}- anti B{sub s} mixing recently observed at Tevatron into account. We also calculate lepton flavor violating processes {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma} and {tau} {yields} e{gamma} for the models with right-handed neutrinos. We investigate possibilities to distinguish the flavor structure of the supersymmetry breaking sector with use of patterns of various flavor signals which are expected to be measured in experiments such as MEG, LHCb and a future Super B Factory. (orig.)

Patterns of flavor signals in supersymmetric models

International Nuclear Information System (INIS)

Goto, T.; Tanaka, M.

2007-11-01

Quark and lepton flavor signals are studied in four supersymmetric models, namely the minimal supergravity model, the minimal supersymmetric standard model with right-handed neutrinos, SU(5) supersymmetric grand unified theory with right-handed neutrinos and the minimal supersymmetric standard model with U(2) flavor symmetry. We calculate b→s(d) transition observables in B d and B s decays, taking the constraint from the B s - anti B s mixing recently observed at Tevatron into account. We also calculate lepton flavor violating processes μ → eγ, τ → μγ and τ → eγ for the models with right-handed neutrinos. We investigate possibilities to distinguish the flavor structure of the supersymmetry breaking sector with use of patterns of various flavor signals which are expected to be measured in experiments such as MEG, LHCb and a future Super B Factory. (orig.)

Non-local deformation of a supersymmetric field theory

Energy Technology Data Exchange (ETDEWEB)

Zhao, Qin [National University of Singapore, Department of Physics, Singapore (Singapore); Faizal, Mir [University of Lethbridge, Department of Physics and Astronomy, Lethbridge (Canada); University of British Columbia - Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); Shah, Mushtaq B.; Ganai, Prince A. [National Institute of Technology, Department of Physics, Srinagar, Kashmir (India); Bhat, Anha [National Institute of Technology, Department of Metallurgical and Materials Engineering, Srinagar (India); Zaz, Zaid [University of Kashmir, Department of Electronics and Communication Engineering, Srinagar, Kashmir (India); Masood, Syed; Raza, Jamil; Irfan, Raja Muhammad [International Islamic University, Department of Physics, Islamabad (Pakistan)

2017-09-15

In this paper, we will analyze a supersymmetric field theory deformed by generalized uncertainty principle and Lifshitz scaling. It will be observed that this deformed supersymmetric field theory contains non-local fractional derivative terms. In order to construct such a deformed N = 1 supersymmetric theory, a harmonic extension of functions will be used. However, the supersymmetry will only be preserved for a free theory and will be broken by the inclusion of interaction terms. (orig.)

Constraints on the rare tau decays from μ→eγ in the supersymmetric see-saw model

International Nuclear Information System (INIS)

Ibarra, Alejandro; Simonetto, Cristoforo

2008-01-01

It is now a firmly established fact that all family lepton numbers are violated in Nature. In this paper we discuss the implications of this observation for future searches for rare tau decays in the supersymmetric see-saw model. Using the two loop renormalization group evolution of the soft terms and the Yukawa couplings we show that there exists a lower bound on the rate of the rare process μ→eγ of the form BR(μ→eγ) ∼> C x BR(τ→μγ)BR(τ→eγ), where C is a constant that depends on supersymmetric parameters. Our only assumption is the absence of cancellations among the high-energy see-saw parameters. We also discuss the implications of this bound for future searches for rare tau decays. In particular, for large regions of the mSUGRA parameter space, we show that present B-factories could discover either τ→μγ or τ→eγ, but not both

Spectral properties in supersymmetric matrix models

International Nuclear Information System (INIS)

Boulton, Lyonell; Garcia del Moral, Maria Pilar; Restuccia, Alvaro

2012-01-01

We formulate a general sufficiency criterion for discreteness of the spectrum of both supersymmmetric and non-supersymmetric theories with a fermionic contribution. This criterion allows an analysis of Hamiltonians in complete form rather than just their semiclassical limits. In such a framework we examine spectral properties of various (1+0) matrix models. We consider the BMN model of M-theory compactified on a maximally supersymmetric pp-wave background, different regularizations of the supermembrane with central charges and a non-supersymmetric model comprising a bound state of N D2 with m D0. While the first two examples have a purely discrete spectrum, the latter has a continuous spectrum with a lower end given in terms of the monopole charge.

Vector supersymmetric multiplets in two dimensions

International Nuclear Information System (INIS)

Khattab, Mohammad

1990-01-01

Author.The invariance of both, N=1 supersymmetric yang-Mills theory and N-1 supersymmetric off-shell Wess-Zumino model in four dimensions is proved. Dimensional reduction is then applied to obtain super Yang-Mills theory with extended supersymmetry, N=2, in two dimensions. The resulting theory is then truncated to N=1 super Yang-Mills and with further truncation, N=1/2 supersymmetry is shown to be possible. Then, using the duality transformations, we find the off-shell supersymmetry algebra is closed and that the auxiliary fields are replaced by four-rank antisymmetric tensors with Gauge symmetry. Finally, the mechanism of dimensional reduction is then applied to obtain N=2 extended off-shell supersymmetric model with two gauge vector fields

Precise determination of the Higgs mass in supersymmetric models with vectorlike tops and the impact on naturalness in minimal GMSB

CERN Document Server

Nickel, Kilian

2015-01-01

We present a precise analysis of the Higgs mass corrections stemming from vectorlike top partners in supersymmetric models. We reduce the theoretical uncertainty compared to previous studies in the following aspects: (i) including the one-loop threshold corrections to SM gauge and Yukawa couplings due to the presence of the new states to obtain the $\\bar{\\text{DR}}$ parameters entering all loop calculations, (ii) including the full momentum dependence at one-loop, and (iii) including all two-loop corrections but the ones involving $g_1$ and $g_2$. We find that the additional threshold corrections are very important and can give the largest effect on the Higgs mass. However, we identify also parameter regions where the new two-loop effects can be more important than the ones of the MSSM and change the Higgs mass prediction by up to 10 GeV. This is for instance the case in the low $\\tan\\beta$, small $M_A$ regime. We use these results to calculate the electroweak fine-tuning of an UV complete variant of this mod...

Supersymmetric regulators and supercurrent anomalies

International Nuclear Information System (INIS)

Majumdar, P.; Poggio, E.C.; Schnitzer, H.J.

1980-01-01

The supercurrent anomalies of the supercurrent deltasub(μ) of the supersymmetric Yang-Mills theory in Wess-Zumino gauge are computed using the supersymmetric dimensional regulator of Siegel. It is shown that γsub(μ)deltasup(μ) = 0 and deltasub(μ)deltasup(μ) unequal 0 in agreement with an earlier calculation based on the Adler-Rosenberg method. The problem of exhibiting the chiral anomaly and a regulator for local supersymmetry suggests that the interpretation of dimensional reduction in component language is incomplete. (orig.)

The gauge technique in supersymmetric QED2

NARCIS (Netherlands)

Roo, M. de; Steringa, J.J.

1988-01-01

We construct an extension of the gauge technique to two-dimensional supersymmetric gauge theories. This involves a derivation of the spectral representation of a scalar superpropagator in two dimensions. We apply the method to the massive supersymmetric Schwinger model. In the case that the gauge

Dynamics of supersymmetric chameleons

International Nuclear Information System (INIS)

Brax, Philippe; Davis, Anne-Christine; Sakstein, Jeremy

2013-01-01

We investigate the cosmological dynamics of a class of supersymmetric chameleon models coupled to cold dark matter fermions. The model includes a cosmological constant in the form of a Fayet-Illiopoulos term, which emerges at late times due to the coupling of the chameleon to two charged scalars. Supergravity corrections ensure that the supersymmetric chameleons are efficiently screened in all astrophysical objects of interest, however this does not preclude the enhancement of gravity on linear cosmological scales. We solve the modified equations for the growth of cold dark matter density perturbations in closed form in the matter era. Using this, we go on to derive the modified linear power spectrum which is characterised by two scales, the horizon size at matter-radiation equality and at the redshift when the chameleon reaches the minimum of its effective potential. We analyse the deviations from the ΛCDM predictions in the linear regime. We find that there is generically a region in the model's parameter space where the model's background cosmology coincides with that of the ΛCDM model. Furthermore, we find that characteristic deviations from ΛCDM are present on the matter power spectrum providing a clear signature of supersymmetric chameleons

Strong/weak coupling duality relations for non-supersymmetric string theories

International Nuclear Information System (INIS)

Blum, J.D.; Dienes, K.R.

1998-01-01

Both the supersymmetric SO(32) and E 8 x E 8 heterotic strings in ten dimensions have known strong-coupling duals. However, it has not been known whether there also exist strong-coupling duals for the non-supersymmetric heterotic strings in ten dimensions. In this paper, we construct explicit open-string duals for the circle compactifications of several of these non-supersymmetric theories, among them the tachyon-free SO(16) x SO(16) string. Our method involves the construction of heterotic and open-string interpolating models that continuously connect non-supersymmetric strings to supersymmetric strings. We find that our non-supersymmetric dual theories have exactly the same massless spectra as their heterotic counterparts within a certain range of our interpolations. We also develop a novel method for analyzing the solitons of non-supersymmetric open-string theories, and find that the solitons of our dual theories also agree with their heterotic counterparts. These are therefore the first known examples of strong/weak coupling duality relations between non-supersymmetric, tachyon-free string theories. Finally, the existence of these strong-coupling duals allows us to examine the non-perturbative stability of these strings, and we propose a phase diagram for the behavior of these strings as a function of coupling and radius. (orig.)

Instantons in supersymmetric theories

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vajnshtejn, A.I.; Zakharov, V.I.

1982-01-01

Instanton effects are considered for a sample of supersymmetric theories: quantum mechanics, gluodynamics. Higgs model. The problem is how to reconcile the apparent lack of the boson-fermion symmetry in the effective instanton induced interaction with supersymmetry of the corresponding lagrangians. It is shown that in case of quantum mechanics and Higgs model there is no conflict between supersymmetry and the instanton calculus since the Ward identities, associated with the supersymmetry transformations, are satisfied. In case of supersymmetric gluodynamics the standard instanton calculus explicity violates the Ward identities. This is due to the lack of symmetry in the standard class of classical solutions used in the instanton calculus

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

Two-loop mass splittings in electroweak multiplets: Winos and minimal dark matter

Science.gov (United States)

McKay, James; Scott, Pat

2018-03-01

The radiatively-induced splitting of masses in electroweak multiplets is relevant for both collider phenomenology and dark matter. Precision two-loop corrections of O (MeV ) to the triplet mass splitting in the wino limit of the minimal supersymmetric standard model can affect particle lifetimes by up to 40%. We improve on previous two-loop self-energy calculations for the wino model by obtaining consistent input parameters to the calculation via two-loop renormalization-group running, and including the effect of finite light quark masses. We also present the first two-loop calculation of the mass splitting in an electroweak fermionic quintuplet, corresponding to the viable form of minimal dark matter (MDM). We place significant constraints on the lifetimes of the charged and doubly-charged fermions in this model. We find that the two-loop mass splittings in the MDM quintuplet are not constant in the large-mass limit, as might naively be expected from the triplet calculation. This is due to the influence of the additional heavy fermions in loop corrections to the gauge boson propagators.

On the maximal superalgebras of supersymmetric backgrounds

International Nuclear Information System (INIS)

Figueroa-O'Farrill, Jose; Hackett-Jones, Emily; Moutsopoulos, George; Simon, Joan

2009-01-01

In this paper we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS 4 X S 7 and find that it is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS 4 X S 7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.

Leptogenesis in the left-right supersymmetric model

International Nuclear Information System (INIS)

Frank, M.

2004-01-01

We analyze the effects of the current neutrino data on thermal leptogenesis and 0νββ decay in a fully left-right extension of the minimal supersymmetric model. The model has several additional phases compared to the minimal supersymmetric model. These phases appear from both the heavy and light neutrino sectors: two CKM-type phases and four Majorana phases which give new contributions to CP-violating parameters and leptogenesis. We study observable effects of these phases on leptogenesis in most general neutrino mixing scenarios, with either hierarchical, inverse hierarchical, or quasidegenerate light and heavy neutrinos. We comment on the effects of these scenarios on the 0νββ decay. The CP-violating phases in both the heavy and light neutrino sectors of the left-right supersymmetric model have unique features, resulting in bounds on heavy neutrino masses different from the minimal scenario in leptogenesis, and which may distinguish the model from other supersymmetric scenarios

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.)

Nonsinglet pentagons and NMHV amplitudes

Directory of Open Access Journals (Sweden)

A.V. Belitsky

2015-07-01

Full Text Available Scattering amplitudes in maximally supersymmetric gauge theory receive a dual description in terms of the expectation value of the super Wilson loop stretched on a null polygonal contour. This makes the analysis amenable to nonperturbative techniques. Presently, we elaborate on a refined form of the operator product expansion in terms of pentagon transitions to compute twist-two contributions to NMHV amplitudes. To start with, we provide a novel derivation of scattering matrices starting from Baxter equations for flux-tube excitations propagating on magnon background. We propose bootstrap equations obeyed by pentagon form factors with nonsinglet quantum numbers with respect to the R-symmetry group and provide solutions to them to all orders in 't Hooft coupling. These are then successfully confronted against available perturbative calculations for NMHV amplitudes to four-loop order.

Nonsinglet pentagons and NMHV amplitudes

Energy Technology Data Exchange (ETDEWEB)

Belitsky, A.V., E-mail: andrei.belitsky@asu.edu

2015-07-15

Scattering amplitudes in maximally supersymmetric gauge theory receive a dual description in terms of the expectation value of the super Wilson loop stretched on a null polygonal contour. This makes the analysis amenable to nonperturbative techniques. Presently, we elaborate on a refined form of the operator product expansion in terms of pentagon transitions to compute twist-two contributions to NMHV amplitudes. To start with, we provide a novel derivation of scattering matrices starting from Baxter equations for flux-tube excitations propagating on magnon background. We propose bootstrap equations obeyed by pentagon form factors with nonsinglet quantum numbers with respect to the R-symmetry group and provide solutions to them to all orders in 't Hooft coupling. These are then successfully confronted against available perturbative calculations for NMHV amplitudes to four-loop order.

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.

Higher dimensional supersymmetric quantum mechanics and Dirac ...

Indian Academy of Sciences (India)

We exhibit the supersymmetric quantum mechanical structure of the full 3+1 dimensional Dirac equation considering `mass' as a function of coordinates. Its usefulness in solving potential problems is discussed with specific examples. We also discuss the `physical' significance of the supersymmetric states in this formalism.

Instantons and Borel resummability for the perturbed supersymmetric anharmonic oscillator

International Nuclear Information System (INIS)

Verbaarschot, J.J.M.; West, P.

1991-01-01

In this paper we give an analytical derivation of the large-order behavior of the perturbation series for both the ground state and the excited states of the supersymmetric anharmonic oscillator and of the anharmonic oscillator obtained from the supersymmetric case by varying the strength of the fermion coupling. The results which are obtained with the help of instanton calculus coincide with those obtained numerically in previous work. The large-order perturbation series of the ground state vanishes in the supersymmetric case, whereas away from the supersymmetric point the perturbation series diverges factorially. The perturbation series of the excited states diverges factorially both at the supersymmetric point and away from this point

Quadratic contributions of softly broken supersymmetry in the light of loop regularization

Energy Technology Data Exchange (ETDEWEB)

Bai, Dong [Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China); Wu, Yue-Liang [Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); International Centre for Theoretical Physics Asia-Pacific (ICTP-AP), Beijing (China); University of Chinese Academy of Sciences, School of Physical Sciences, Beijing (China)

2017-09-15

Loop regularization (LORE) is a novel regularization scheme in modern quantum field theories. It makes no change to the spacetime structure and respects both gauge symmetries and supersymmetry. As a result, LORE should be useful in calculating loop corrections in supersymmetry phenomenology. To further demonstrate its power, in this article we revisit in the light of LORE the old issue of the absence of quadratic contributions (quadratic divergences) in softly broken supersymmetric field theories. It is shown explicitly by Feynman diagrammatic calculations that up to two loops the Wess-Zumino model with soft supersymmetry breaking terms (WZ' model), one of the simplest models with the explicit supersymmetry breaking, is free of quadratic contributions. All the quadratic contributions cancel with each other perfectly, which is consistent with results dictated by the supergraph techniques. (orig.)

Goldstone fermions in supersymmetric theories at finite temperature

International Nuclear Information System (INIS)

Aoyama, H.; Boyanovsky, D.

1984-01-01

The behavior of supersymmetric theories at finite temperature is examined. It is shown that supersymmetry is broken for any T> or =0 because of the different statistics obeyed by bosons and fermions. This breaking is always associated with a Goldstone mode(s). This phenomenon is shown to take place even in a free massive theory, where the Goldstone modes are created by composite fermion-boson bilinear operators. In the interacting theory with chiral symmetry, the same bilinear operators create the chiral doublet of Goldstone fermions, which is shown to saturate the Ward-Takahashi identities up to one loop. Because of this spontaneous supersymmetry breaking, the fermions and the bosons acquire different effective masses. In theories without chiral symmetry, at the tree level the fermion-boson bilinear operators create Goldstone modes, but at higher orders these modes become massive and the elementary fermion becomes the Goldstone field because of the mixing with these bilinear operators

Study of Higgs self couplings of a supersymmetric E6 model at the international linear collider

International Nuclear Information System (INIS)

Ham, S. W.; Han, K. D.; Lee, J. I.; Oh, S. K.

2010-01-01

We study the Higgs self couplings of a supersymmetric E 6 model that has two Higgs doublets and two Higgs singlets. The lightest scalar Higgs boson in the model may be heavier than 112 GeV, at the one-loop level, where the negative results for the Higgs search at the LEP2 experiments are taken into account. The contributions from the top and scalar top quark loops are included in the radiative corrections to the one-loop mass of the lightest scalar Higgs boson in the effective potential approximation. The effect of the Higgs self couplings may be observed in the production of the lightest scalar Higgs bosons in e + e - collisions at the International Linear Collider (ILC) via the double Higgs-strahlung process. For the center of mass energy of 500 GeV with an integrated luminosity of 500 fb -1 and an efficiency of 20%, we expect that at least 5 events of the lightest scalar Higgs boson may be produced at the ILC via the double Higgs-strahlung process.

Supersymmetric quantum corrections and Poisson-Lie T-duality

International Nuclear Information System (INIS)

Assaoui, F.; Lhallabi, T.; Abdus Salam International Centre for Theoretical Physics, Trieste

2000-07-01

The quantum actions of the (4,4) supersymmetric non-linear sigma model and its dual in the Abelian case are constructed by using the background superfield method. The propagators of the quantum superfield and its dual and the gauge fixing actions of the original and dual (4,4) supersymmetric sigma models are determined. On the other hand, the BRST transformations are used to obtain the quantum dual action of the (4,4) supersymmetric nonlinear sigma model in the sense of Poisson-Lie T-duality. (author)

Nearly Supersymmetric Dark Atoms

Energy Technology Data Exchange (ETDEWEB)

Behbahani, Siavosh R.; Jankowiak, Martin; /SLAC /Stanford U., ITP; Rube, Tomas; /Stanford U., ITP; Wacker, Jay G.; /SLAC /Stanford U., ITP

2011-08-12

Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions with the Standard Model communicate supersymmetry breaking to the dark sector. In these models supersymmetry breaking can be treated as a perturbation on the spectrum of bound states. Using a general formalism, the spectrum with leading supersymmetry effects is computed without specifying the details of the binding dynamics. The interactions of the composite states with the Standard Model are computed and several benchmark models are described. General features of non-relativistic supersymmetric bound states are emphasized.

High-precision predictions for the light CP-even Higgs boson mass of the minimal supersymmetric standard model.

Science.gov (United States)

Hahn, T; Heinemeyer, S; Hollik, W; Rzehak, H; Weiglein, G

2014-04-11

For the interpretation of the signal discovered in the Higgs searches at the LHC it will be crucial in particular to discriminate between the minimal Higgs sector realized in the standard model (SM) and its most commonly studied extension, the minimal supersymmetric standard model (MSSM). The measured mass value, having already reached the level of a precision observable with an experimental accuracy of about 500 MeV, plays an important role in this context. In the MSSM the mass of the light CP-even Higgs boson, Mh, can directly be predicted from the other parameters of the model. The accuracy of this prediction should at least match the one of the experimental result. The relatively high mass value of about 126 GeV has led to many investigations where the scalar top quarks are in the multi-TeV range. We improve the prediction for Mh in the MSSM by combining the existing fixed-order result, comprising the full one-loop and leading and subleading two-loop corrections, with a resummation of the leading and subleading logarithmic contributions from the scalar top sector to all orders. In this way for the first time a high-precision prediction for the mass of the light CP-even Higgs boson in the MSSM is possible all the way up to the multi-TeV region of the relevant supersymmetric particles. The results are included in the code FEYNHIGGS.

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.)

Dynamics of supersymmetric chameleons

Energy Technology Data Exchange (ETDEWEB)

Brax, Philippe [Institut de Physique Theorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Davis, Anne-Christine; Sakstein, Jeremy, E-mail: Philippe.Brax@cea.fr, E-mail: A.C.Davis@damtp.cam.ac.uk, E-mail: J.A.Sakstein@damtp.cam.ac.uk [DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2013-10-01

We investigate the cosmological dynamics of a class of supersymmetric chameleon models coupled to cold dark matter fermions. The model includes a cosmological constant in the form of a Fayet-Illiopoulos term, which emerges at late times due to the coupling of the chameleon to two charged scalars. Supergravity corrections ensure that the supersymmetric chameleons are efficiently screened in all astrophysical objects of interest, however this does not preclude the enhancement of gravity on linear cosmological scales. We solve the modified equations for the growth of cold dark matter density perturbations in closed form in the matter era. Using this, we go on to derive the modified linear power spectrum which is characterised by two scales, the horizon size at matter-radiation equality and at the redshift when the chameleon reaches the minimum of its effective potential. We analyse the deviations from the ΛCDM predictions in the linear regime. We find that there is generically a region in the model's parameter space where the model's background cosmology coincides with that of the ΛCDM model. Furthermore, we find that characteristic deviations from ΛCDM are present on the matter power spectrum providing a clear signature of supersymmetric chameleons.

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.

Precision LEP data, supersymmetric GUTs and string unification

International Nuclear Information System (INIS)

Ellis, J.; Kelley, S.; Nanopoulos, D.V.; Houston Area Research Center

1990-01-01

The precision of sin 2 θ w MS (m Z ) extracted from LEP data (0.233±0.001) confirms the prediction of minimal supersymmetric GUTs (0.235±0.004) within the errors of about 2%. Moreover, supersymmetric GUTs with three generations and a heavy top quark also predict m b =5.2±0.3 GeV in perfect agreement with potential model estimates (5.0±0.2 GeV). String unification would require that the effective grand unification scale m GUT be no larger than the effective string unification scale m SU , which is indeed consistent with the LEP data, which indicate m GUT ≅ 2x10 16 GeV in a minimal supersymmetric GUT, compared with the theoretical estimate m SU ≅ 10 17 GeV. Specific choices of the string model moduli could enforce m GUT =m SU even in minimal supersymmetric GUTs, whilst non-minimal supersymmetric GUTs can reconcile the successful predictions of sin 2 θ w with m GUT = m SU for generic values of the moduli, but tend to have m b too large. (orig.)

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 ...

On radiative corrections to supersymmetric Higgs boson masses and their implications for LEP searches

International Nuclear Information System (INIS)

Ellis, J.; Zwirner, F.

1991-01-01

We present calculations of the one-loop radiative corrections to the mass of the neutral CP-odd Higgs boson (A) in the minimal supersymmetric extension of the standard model, as well as to the neutral CP-even Higgs (h, H) masses and mixing angles. We use these results to recalculate the cross-sections for Higgs production at LEP in the h + (Z * + fanti f), h (H)Z 0 and h (H) A final states. We delineate the domains of parameter space accessible at LEP at the Z 0 peak and at LEP II with a center-of-mass energy of 180, 190 or 200 GeV. (orig.)

Supersymmetric Yang-Mills theory on conformal supergravity backgrounds in ten dimensions

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Paul de; Figueroa-O’Farrill, José [Maxwell Institute and School of Mathematics, The University of Edinburgh,James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD (United Kingdom)

2016-03-14

We consider bosonic supersymmetric backgrounds of ten-dimensional conformal supergravity. Up to local conformal isometry, we classify the maximally supersymmetric backgrounds, determine their conformal symmetry superalgebras and show how they arise as near-horizon geometries of certain half-BPS backgrounds or as a plane-wave limit thereof. We then show how to define Yang-Mills theory with rigid supersymmetry on any supersymmetric conformal supergravity background and, in particular, on the maximally supersymmetric backgrounds. We conclude by commenting on a striking resemblance between the supersymmetric backgrounds of ten-dimensional conformal supergravity and those of eleven-dimensional Poincaré supergravity.

Production and decay of supersymmetric particles at future colliders

International Nuclear Information System (INIS)

Bartl, A.; Majerotto, W.; Moesslacher, B.

1991-01-01

We describe how supersymmetric particles could be detected at the new colliders HERA, LEP 200, LHC, SSC, and at the possible future linear e + e - collider. We shall present theoretical predictions for production cross sections and decay probabilities, as well as for the important signatures. Our calculations will be based on the Minimal Supersymmetric Standard Model (MSSM) which is the simplest supersymmetric extension of the Standard Model. (authors)

Electroweak symmetry breaking in supersymmetric models with heavy scalar superpartners

International Nuclear Information System (INIS)

Chankowski, Piotr H.; Falkowski, Adam; Pokorski, Stefan; Wagner, Jakub

2004-01-01

We propose a novel mechanism of electroweak symmetry breaking in supersymmetric models, as the one recently discussed by Birkedal, Chacko and Gaillard, in which the Standard Model Higgs doublet is a pseudo-Goldstone boson of some global symmetry. The Higgs mass parameter is generated at one-loop level by two different, moderately fine-tuned sources of the global symmetry breaking. The mechanism works for scalar superpartner masses of order 10 TeV, but gauginos can be light. The scale at which supersymmetry breaking is mediated to the visible sector has to be low, of order 100 TeV. Fine-tuning in the scalar potential is at least two orders of magnitude smaller than in the MSSM with similar soft scalar masses. The physical Higgs boson mass is (for tanβ >> 1) in the range 120-135 GeV

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.

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.

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.

Search for Minimal Standard Model and Minimal Supersymmetric Model Higgs Bosons in e+ e- Collisions with the OPAL detector at LEP

International Nuclear Information System (INIS)

Ganel, Ofer

1993-06-01

When LEP machine was turned on in August 1989, a new era had opened. For the first time, direct, model-independent searches for Higgs boson could be carried out. The Minimal Standard Model Higgs boson is expected to be produced in e + e - collisions via the H o Z o . The Minimal Supersymmetric Model Higgs boson are expected to be produced in the analogous e + e - -> h o Z o process or in pairs via the process e + e - -> h o A o . In this thesis we describe the search for Higgs bosons within the framework of the Minimal Standard Model and the Minimal Supersymmetric Model, using the data accumulated by the OPAL detector at LEP in the 1989, 1990, 1991 and part of the 1992 running periods at and around the Z o pole. An MInimal Supersymmetric Model Higgs boson generator is described as well as its use in several different searches. As a result of this work, the Minimal Standard Model Higgs boson mass is bounded from below by 54.2 GeV/c 2 at 95% C.L. This is, at present, the highest such bound. A novel method of overcoming the m τ and m s dependence of Minimal Supersymmetric Higgs boson production and decay introduced by one-loop radiative corrections is used to obtain model-independent exclusion. The thesis describes also an algorithm for off line identification of calorimeter noise in the OPAL detector. (author)

A new gauge for supersymmetric abelian gauge theories

International Nuclear Information System (INIS)

Smith, A.W.; Barcelos Neto, J.

1984-01-01

A new gauge for supersymmetric abelian gauge theories is presented. It is shown that this new gauge allows us to obtain terms which usually come as radiative corrections to the supersymmetric abelian gauge theories when one uses the Wess-Zumino gauge. (Author) [pt

On quantization of supersymmetric theories

International Nuclear Information System (INIS)

Smilga, A.V.

1985-01-01

A recipe to resolve ordering ambiguities in the quantum hamiltonian of supersymmetric theories is suggested. The Weyl ordering prescription for supercharge operators should be employed to preserve SUSY algebra on the quantum level. The quantum hamiltonian does not generally coincide with the Weyl ordered classical hamiltonian, the difference being due to the fact that the Weyl symbol of anticommutator of supercharges does not generally coincide with the Poisson bracket of their Weyl symbols (i.e. the classical hamiltonian). The suggested procedure is applied in the examples of N=1 and N=2 supersymmetric σ-models analyzed in the constant field limit

N=2 supersymmetric dynamics for pedestrians

CERN Document Server

Tachikawa, Yuji

2015-01-01

Understanding the dynamics of gauge theories is crucial, given the fact that all known interactions are based on the principle of local gauge symmetry. Beyond the perturbative regime, however, this is a notoriously difficult problem. Requiring invariance under supersymmetry turns out to be a suitable tool for analyzing supersymmetric gauge theories over a larger region of the space of parameters. Supersymmetric quantum field theories in four dimensions with extended N=2 supersymmetry are further constrained and have therefore been a fertile field of research in theoretical physics for quite some time. Moreover, there are far-reaching mathematical ramifications that have led to a successful dialogue with differential and algebraic geometry. These lecture notes aim to introduce students of modern theoretical physics to the fascinating developments in the understanding of N=2 supersymmetric gauge theories in a coherent fashion. Starting with a gentle introduction to electric-magnetic duality, the author guides r...

The Supersymmetric Effective Field Theory of Inflation

Energy Technology Data Exchange (ETDEWEB)

Delacrétaz, Luca V.; Gorbenko, Victor [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94306 (United States); Senatore, Leonardo [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94306 (United States); Kavli Institute for Particle Astrophysics and Cosmology, Stanford University and SLAC,Menlo Park, CA 94025 (United States)

2017-03-10

We construct the Supersymmetric Effective Field Theory of Inflation, that is the most general theory of inflationary fluctuations when time-translations and supersymmetry are spontaneously broken. The non-linear realization of these invariances allows us to define a complete SUGRA multiplet containing the graviton, the gravitino, the Goldstone of time translations and the Goldstino, with no auxiliary fields. Going to a unitary gauge where only the graviton and the gravitino are present, we write the most general Lagrangian built out of the fluctuations of these fields, invariant under time-dependent spatial diffeomorphisms, but softly-breaking time diffeomorphisms and gauged SUSY. With a suitable Stückelberg transformation, we introduce the Goldstone boson of time translation and the Goldstino of SUSY. No additional dynamical light field is needed. In the high energy limit, larger than the inflationary Hubble scale for the Goldstino, these fields decouple from the graviton and the gravitino, greatly simplifying the analysis in this regime. We study the phenomenology of this Lagrangian. The Goldstino can have a non-relativistic dispersion relation. Gravitino and Goldstino affect the primordial curvature perturbations at loop level. The UV modes running in the loops generate three-point functions which are degenerate with the ones coming from operators already present in the absence of supersymmetry. Their size is potentially as large as corresponding to f{sub NL}{sup equil.,orthog.}∼1 or, for particular operators, even ≫1. The non-degenerate contribution from modes of order H is estimated to be very small.

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 ...

The SU(2|3) dynamic two-loop form factors

International Nuclear Information System (INIS)

Brandhuber, A.; Kostacińska, M.; Penante, B.; Travaglini, G.; Young, D.

2016-01-01

We compute two-loop form factors of operators in the SU(2|3) closed subsector of N = 4 supersymmetric Yang-Mills. In particular, we focus on the non-protected, dimension-three operators Tr(X[Y,Z]) and Tr(ψψ) for which we compute the four possible two-loop form factors, and corresponding remainder functions, with external states 〈X̄ȲZ̄| and 〈ψ̄ψ̄|. Interestingly, the maximally transcendental part of the two-loop remainder of 〈X̄ȲZ̄|Tr(X[Y,Z])|0〉 turns out to be identical to that of the corresponding known quantity for the half-BPS operator Tr(X"3). We also find a surprising connection between the terms subleading in transcendentality and certain a priori unrelated remainder densities introduced in the study of the spin chain Hamiltonian in the SU(2) sector. Next, we use our calculation to resolve the mixing, recovering anomalous dimensions and eigenstates of the dilatation operator in the SU(2|3) sector at two loops. We also speculate on potential connections between our calculations in N = 4 super Yang-Mills and Higgs + multi-gluon amplitudes in QCD in an effective Lagrangian approach.

The SU(2|3) dynamic two-loop form factors

Energy Technology Data Exchange (ETDEWEB)

Brandhuber, A.; Kostacińska, M. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Penante, B. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Institut für Physik und IRIS Adlershof, Humboldt Universität zu Berlin,Zum Großen Windkanal 6, 12489 Berlin (Germany); Travaglini, G.; Young, D. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom)

2016-08-23

We compute two-loop form factors of operators in the SU(2|3) closed subsector of N = 4 supersymmetric Yang-Mills. In particular, we focus on the non-protected, dimension-three operators Tr(X[Y,Z]) and Tr(ψψ) for which we compute the four possible two-loop form factors, and corresponding remainder functions, with external states 〈X̄ȲZ̄| and 〈ψ̄ψ̄|. Interestingly, the maximally transcendental part of the two-loop remainder of 〈X̄ȲZ̄|Tr(X[Y,Z])|0〉 turns out to be identical to that of the corresponding known quantity for the half-BPS operator Tr(X{sup 3}). We also find a surprising connection between the terms subleading in transcendentality and certain a priori unrelated remainder densities introduced in the study of the spin chain Hamiltonian in the SU(2) sector. Next, we use our calculation to resolve the mixing, recovering anomalous dimensions and eigenstates of the dilatation operator in the SU(2|3) sector at two loops. We also speculate on potential connections between our calculations in N = 4 super Yang-Mills and Higgs + multi-gluon amplitudes in QCD in an effective Lagrangian approach.

Solvable potentials derived from supersymmetric quantum mechanics

International Nuclear Information System (INIS)

Levai, G.

1994-01-01

The introduction of supersymmetric quantum mechanics has generated renewed interest in solvable problems of non-relativistic quantum mechanics. This approach offers an elegant way to describe different, but isospectral potentials by interpreting the degeneracy of their energy levels in terms of supersymmetry. The original ideas of supersymmetric quantum mechanics have been developed further in many respects in the past ten years, and have been applied to a large variety of physical problems. The purpose of this contribution is to give a survey of supersymmetric quantum mechanics and its applications to solvable quantum mechanical potentials. Its relation to other models describing isospectral potentials is also discussed here briefly, as well as some of its practical applications in various branches of physics. (orig.)

Massive 3-loop ladder diagrams for quarkonic local operator matrix elements

International Nuclear Information System (INIS)

Ablinger, Jakob; Blümlein, Johannes; Hasselhuhn, Alexander; Klein, Sebastian; Schneider, Carsten; Wißbrock, Fabian

2012-01-01

3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable N using Appell-function representations and applying modern summation technologies provided by the package Sigma and the method of hyperlogarithms. In some of the diagrams generalized harmonic sums with ξ∈{1,1/2,2} emerge beyond the usual nested harmonic sums. As the asymptotic representation of the corresponding integrals shows, the generalized sums conspire giving well behaved expressions for large values of N. These diagrams contribute to the 3-loop heavy flavor Wilson coefficients of the structure functions in deep-inelastic scattering in the region Q 2 ≫m 2 .

Hidden simplicity of gauge theory amplitudes

Energy Technology Data Exchange (ETDEWEB)

Drummond, J M, E-mail: drummond@lapp.in2p3.f [LAPTH, Universite de Savoie, CNRS, B.P. 110, F-74941 Annecy-le-Vieux, Cedex (France)

2010-11-07

These notes were given as lectures at the CERN Winter School on Supergravity, Strings and Gauge Theory 2010. We describe the structure of scattering amplitudes in gauge theories, focussing on the maximally supersymmetric theory to highlight the hidden symmetries which appear. Using the Britto, Cachzo, Feng and Witten (BCFW) recursion relations we solve the tree-level S-matrix in N=4 super Yang-Mills theory and describe how it produces a sum of invariants of a large symmetry algebra. We review amplitudes in the planar theory beyond tree level, describing the connection between amplitudes and Wilson loops, and discuss the implications of the hidden symmetries.

A supersymmetric SYK-like tensor model

Energy Technology Data Exchange (ETDEWEB)

Peng, Cheng; Spradlin, Marcus; Volovich, Anastasia [Department of Physics, Brown University,Providence, RI, 02912 (United States)

2017-05-11

We consider a supersymmetric SYK-like model without quenched disorder that is built by coupling two kinds of fermionic N=1 tensor-valued superfields, “quarks” and “mesons”. We prove that the model has a well-defined large-N limit in which the (s)quark 2-point functions are dominated by mesonic “melon” diagrams. We sum these diagrams to obtain the Schwinger-Dyson equations and show that in the IR, the solution agrees with that of the supersymmetric SYK model.

A supersymmetric SYK-like tensor model

International Nuclear Information System (INIS)

Peng, Cheng; Spradlin, Marcus; Volovich, Anastasia

2017-01-01

We consider a supersymmetric SYK-like model without quenched disorder that is built by coupling two kinds of fermionic N=1 tensor-valued superfields, “quarks” and “mesons”. We prove that the model has a well-defined large-N limit in which the (s)quark 2-point functions are dominated by mesonic “melon” diagrams. We sum these diagrams to obtain the Schwinger-Dyson equations and show that in the IR, the solution agrees with that of the supersymmetric SYK model.

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.

Supersymmetric quantum mechanics

International Nuclear Information System (INIS)

Crombrugghe, M. de; Rittenberg, V.

1982-12-01

We give a general construction for supersymmetric Hamiltonians in quantum mechanics. We find that N-extended supersymmetry imposes very strong constraints, and for N > 4 the Hamiltonian is integrable. We give a variety of examples, for one-particle and for many-particle systems, in different numbers of dimensions. (orig.)

N=1 supersymmetric extension of the baby Skyrme model

International Nuclear Information System (INIS)

Adam, C.; Queiruga, J. M.; Sanchez-Guillen, J.; Wereszczynski, A.

2011-01-01

We construct a method to supersymmetrize higher kinetic terms and apply it to the baby Skyrme model. We find that there exist N=1 supersymmetric extensions for baby Skyrme models with arbitrary potential.

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…

Fun with supersymmetric quantum mechanics

International Nuclear Information System (INIS)

Freedman, B.; Cooper, F.

1984-04-01

One reason for studying supersymmetric quantum mechanics is that there are a class of superpotentials W(x) which behave at large x as x/sup α/ for which we know from general arguments whether SUSY is broken or unbroken. Thus one can use these superpotentials to test various ideas about how to see if supersymmetry is broken in an arbitrary model. Recently, Witten proposed a topological invariant, the Witten index Δ which counts the number of bosons minus the number of fermions having ground state energy zero. Since if supersymmetry is broken, the ground state energy cannot be zero, one expects if Δ is not zero, SUSY is preserved and the theory is not a good candidate for a realistic model. In this study we evaluate Δ for several examples, and show some unexpected peculiarities of the Witten index for certain choice of superpotentials W(x). We also discuss two other nonperturbative methods of studying supersymmetry breakdown. One involves relating supersymmetric quantum mechanics to a stochastic classical problem and the other involves considering a discrete (but not supersymmetric) version of the theory and studying its behavior as one removes the lattice cuttoff. In this survey we review the Hamiltonian and path integral approaches to supersymmetric quantum mechanics. We then discuss the related path integrals for the Witten Index and for stochastic processes and show how they are indications for supersymmetry breakdown. We then discuss a system where the superpotential W(x) has assymetrical values at +-infinity. We finally discuss nonperturbative strategies for studying supersymmetry breakdown based on introducing a lattice and studying the behavior of the ground state energy as the lattice cutoff is removed. 17 references

Cosmological consequences of supersymmetric flat directions

CERN Document Server

Riva, Francesco; Sarkar, Subir; Giudice, Gian

In this work we analyze various implications of the presence of large field vacum expectation values (VEVs) along supersymmetric flat direct ions during the early universe. First, we discuss supersymmetric leptogenesis and the grav itino bound. Supersym- metric thermal leptogenesis with a hierarchical right-han ded neutrino mass spectrum normally requires the mass of the lightest right-handed neu trino to be heavier than about 10 9 GeV. This is in conflict with the upper bound on the reheating t empera- ture which is found by imposing that the gravitinos generate d during the reheating stage after inflation do not jeopardize successful nucleosy nthesis. We show that a solution to this tension is actually already incorporated i n the framework, because of the presence of flat directions in the supersymmetric scalar potential. Massive right- handed neutrinos are efficiently produced non-thermally and the observed baryon asymmetry can be explained even for a reheating temperature respecting the grav- itino bound...

Supersymmetric Janus solutions in four dimensions

Energy Technology Data Exchange (ETDEWEB)

Bobev, Nikolay [Perimeter Institute for Theoretical Physics,31 Caroline Street North, ON N2L 2Y5 (Canada); Pilch, Krzysztof [Department of Physics and Astronomy, University of Southern California,Los Angeles, CA 90089 (United States); Warner, Nicholas P. [Department of Physics and Astronomy, University of Southern California,Los Angeles, CA 90089 (United States); Institut de Physique Théorique, CEA Saclay,CNRS-URA 2306, 91191 Gif sur Yvette (France); Institut des Hautes Etudes Scientifiques,Le Bois-Marie, 35 route de Chartres, Bures-sur-Yvette, 91440 (France)

2014-06-10

We use maximal gauged supergravity in four dimensions to construct the gravity dual of a class of supersymmetric conformal interfaces in the theory on the world-volume of multiple M2-branes. We study three classes of examples in which the (1+1)-dimensional defects preserve (4,4), (0,2) or (0,1) supersymmetry. Many of the solutions have the maximally supersymmetric AdS{sub 4} vacuum dual to the N=8 ABJM theory on both sides of the interface. We also find new special classes of solutions including one that interpolates between the maximally supersymmetric vacuum and a conformal fixed point with N=1 supersymmetry and G{sub 2} global symmetry. We find another solution that interpolates between two distinct conformal fixed points with N=1 supersymmetry and G{sub 2} global symmetry. In eleven dimensions, this G{sub 2} to G{sub 2} solution corresponds to a domain wall across which a magnetic flux reverses orientation.

Supersymmetric Janus solutions in four dimensions

International Nuclear Information System (INIS)

Bobev, Nikolay; Pilch, Krzysztof; Warner, Nicholas P.

2014-01-01

We use maximal gauged supergravity in four dimensions to construct the gravity dual of a class of supersymmetric conformal interfaces in the theory on the world-volume of multiple M2-branes. We study three classes of examples in which the (1+1)-dimensional defects preserve (4,4), (0,2) or (0,1) supersymmetry. Many of the solutions have the maximally supersymmetric AdS 4 vacuum dual to the N=8 ABJM theory on both sides of the interface. We also find new special classes of solutions including one that interpolates between the maximally supersymmetric vacuum and a conformal fixed point with N=1 supersymmetry and G 2 global symmetry. We find another solution that interpolates between two distinct conformal fixed points with N=1 supersymmetry and G 2 global symmetry. In eleven dimensions, this G 2 to G 2 solution corresponds to a domain wall across which a magnetic flux reverses orientation

Structure of UV divergences in maximally supersymmetric gauge theories

Science.gov (United States)

Kazakov, D. I.; Borlakov, A. T.; Tolkachev, D. M.; Vlasenko, D. E.

2018-06-01

We consider the UV divergences up to sub-subleading order for the four-point on-shell scattering amplitudes in D =8 supersymmetric Yang-Mills theory in the planar limit. We trace how the leading, subleading, etc divergences appear in all orders of perturbation theory. The structure of these divergences is typical for any local quantum field theory independently on renormalizability. We show how the generalized renormalization group equations allow one to evaluate the leading, subleading, etc. contributions in all orders of perturbation theory starting from one-, two-, etc. loop diagrams respectively. We focus then on subtraction scheme dependence of the results and show that in full analogy with renormalizable theories the scheme dependence can be absorbed into the redefinition of the couplings. The only difference is that the role of the couplings play dimensionless combinations like g2s2 or g2t2, where s and t are the Mandelstam variables.

Small numbers in supersymmetric theories of nature

International Nuclear Information System (INIS)

Graesser, Michael L.

1999-01-01

The Standard Model of particle interactions is a successful theory for describing the interactions of quarks, leptons and gauge bosons at microscopic distance scales. Despite these successes, the theory contains many unsatisfactory features. The origin of particle masses is a central mystery that has eluded experimental elucidation. In the Standard Model the known particles obtain their mass from the condensate of the so-called Higgs particle. Quantum corrections to the Higgs mass require an unnatural fine tuning in the Higgs mass of one part in 10 -32 to obtain the correct mass scale of electroweak physics. In addition, the origin of the vast hierarchy between the mass scales of the electroweak and quantum gravity physics is not explained in the current theory. Supersymmetric extensions to the Standard Model are not plagued by this fine tuning issue and may therefore be relevant in Nature. In the minimal supersymmetric Standard Model there is also a natural explanation for electroweak symmetry breaking. Supersymmetric Grand Unified Theories also correctly predict a parameter of the Standard Model. This provides non-trivial indirect evidence for these theories. The most general supersymmetric extension to the Standard Model however, is excluded by many physical processes, such as rare flavor changing processes, and the non-observation of the instability of the proton. These processes provide important information about the possible structure such a theory. In particular, certain parameters in this theory must be rather small. A physics explanation for why this is the case would be desirable. It is striking that the gauge couplings of the Standard Model unify if there is supersymmetry close to the weak scale. This suggests that at high energies Nature is described by a supersymmetric Grand Unified Theory. But the mass scale of unification must be introduced into the theory since it does not coincide with the probable mass scale of strong quantum gravity. The subject

Supersymmetric flipped SU(5) revitalized

Energy Technology Data Exchange (ETDEWEB)

Antoniadis, I.; Ellis, J.; Hagelin, J.S.; Nanopoulos, D.V.

1987-08-06

We describe a simple N = 1 supersymmetric GUT based on the group SU(5) x U(1) which has the following virtues: the gauge group is broken down to the SU(3)/sub C/ x SU(2)/sub L/ x U(1)/sub y/ of the standard model using just 10, 10 Higgs representations, and the doublet-triplet mass splitting problem is solved naturally by a very simple missing-partner mechanism. The successful supersymmetric GUT prediction for sin/sup 2/theta/sub w/ can be maintained, whilst there are no fermion mass relations. The gauge group and representation structure of the model may be obtainable from the superstring.

Early universe cosmology. In supersymmetric extensions of the standard model

International Nuclear Information System (INIS)

Baumann, Jochen Peter

2012-01-01

In this thesis we investigate possible connections between cosmological inflation and leptogenesis on the one side and particle physics on the other side. We work in supersymmetric extensions of the Standard Model. A key role is played by the right-handed sneutrino, the superpartner of the right-handed neutrino involved in the type I seesaw mechanism. We study a combined model of inflation and non-thermal leptogenesis that is a simple extension of the Minimal Supersymmetric Standard Model (MSSM) with conserved R-parity, where we add three right-handed neutrino super fields. The inflaton direction is given by the imaginary components of the corresponding scalar component fields, which are protected from the supergravity (SUGRA) η-problem by a shift symmetry in the Kaehler potential. We discuss the model first in a globally supersymmetric (SUSY) and then in a supergravity context and compute the inflationary predictions of the model. We also study reheating and non-thermal leptogenesis in this model. A numerical simulation shows that shortly after the waterfall phase transition that ends inflation, the universe is dominated by right-handed sneutrinos and their out-of-equilibrium decay can produce the desired matter-antimatter asymmetry. Using a simplified time-averaged description, we derive analytical expressions for the model predictions. Combining the results from inflation and leptogenesis allows us to constrain the allowed parameter space from two different directions, with implications for low energy neutrino physics. As a second thread of investigation, we discuss a generalisation of the inflationary model discussed above to include gauge non-singlet fields as inflatons. This is motivated by the fact that in left-right symmetric, supersymmetric Grand Unified Theories (SUSY GUTs), like SUSY Pati-Salam unification or SUSY SO(10) GUTs, the righthanded (s)neutrino is an indispensable ingredient and does not have to be put in by hand as in the MSSM. We discuss the

Early universe cosmology. In supersymmetric extensions of the standard model

Energy Technology Data Exchange (ETDEWEB)

Baumann, Jochen Peter

2012-03-19

In this thesis we investigate possible connections between cosmological inflation and leptogenesis on the one side and particle physics on the other side. We work in supersymmetric extensions of the Standard Model. A key role is played by the right-handed sneutrino, the superpartner of the right-handed neutrino involved in the type I seesaw mechanism. We study a combined model of inflation and non-thermal leptogenesis that is a simple extension of the Minimal Supersymmetric Standard Model (MSSM) with conserved R-parity, where we add three right-handed neutrino super fields. The inflaton direction is given by the imaginary components of the corresponding scalar component fields, which are protected from the supergravity (SUGRA) {eta}-problem by a shift symmetry in the Kaehler potential. We discuss the model first in a globally supersymmetric (SUSY) and then in a supergravity context and compute the inflationary predictions of the model. We also study reheating and non-thermal leptogenesis in this model. A numerical simulation shows that shortly after the waterfall phase transition that ends inflation, the universe is dominated by right-handed sneutrinos and their out-of-equilibrium decay can produce the desired matter-antimatter asymmetry. Using a simplified time-averaged description, we derive analytical expressions for the model predictions. Combining the results from inflation and leptogenesis allows us to constrain the allowed parameter space from two different directions, with implications for low energy neutrino physics. As a second thread of investigation, we discuss a generalisation of the inflationary model discussed above to include gauge non-singlet fields as inflatons. This is motivated by the fact that in left-right symmetric, supersymmetric Grand Unified Theories (SUSY GUTs), like SUSY Pati-Salam unification or SUSY SO(10) GUTs, the righthanded (s)neutrino is an indispensable ingredient and does not have to be put in by hand as in the MSSM. We discuss

Framing and localization in Chern-Simons theories with matter

Energy Technology Data Exchange (ETDEWEB)

Bianchi, Marco S. [Center for Research in String Theory - School of Physics and Astronomy,Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom); Griguolo, Luca [Dipartimento di Fisica e Scienze della Terra, Università di Parma andINFN Gruppo Collegato di Parma,Viale G.P. Usberti 7/A, 43100 Parma (Italy); Leoni, Matias [Physics Department, FCEyN-UBA & IFIBA-CONICET,Ciudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Mauri, Andrea [Dipartimento di Fisica, Università degli studi di Milano-Bicocca,Piazza della Scienza 3, I-20126 Milano (Italy); Penati, Silvia [Dipartimento di Fisica, Università degli studi di Milano-Bicocca,Piazza della Scienza 3, I-20126 Milano (Italy); INFN, Sezione di Milano-Bicocca,Piazza della Scienza 3, I-20126 Milano (Italy); Seminara, Domenico [Dipartimento di Fisica, Università di Firenze and INFN Sezione di Firenze,via G. Sansone 1, 50019 Sesto Fiorentino (Italy)

2016-06-22

Supersymmetric localization provides exact results that should match QFT computations in some regularization scheme. The agreement is particularly subtle in three dimensions where complex answers from localization procedure sometimes arise. We investigate this problem by studying the expectation value of the 1/6 BPS Wilson loop in planar ABJ(M) theory at three loops in perturbation theory. We reproduce the corresponding term in the localization result and argue that it originates entirely from a non-trivial framing of the circular contour. Contrary to pure Chern-Simons theory, we point out that for ABJ(M) the framing phase is a non-trivial function of the couplings and that it potentially receives contributions from vertex-like diagrams. Finally, we briefly discuss the intimate link between the exact framing factor and the Bremsstrahlung function of the 1/2-BPS cusp.

Supersymmetric sigma models and composite Yang-Mills theory

International Nuclear Information System (INIS)

Lukierski, J.

1980-04-01

We describe two types of supersymmetric sigma models: with field values in supercoset space and with superfields. The notion of Riemannian symmetric pair (H,G/H) is generalized to supergroups. Using the supercoset approach the superconformal-invariant model of composite U(n) Yang-Mills fields in introduced. In the framework of the superfield approach we present with some details two versions of the composite N=1 supersymmetric Yang-Mills theory in four dimensions with U(n) and U(m) x U(n) local invariance. We argue that especially the superfield sigma models can be used for the description of pre-QCD supersymmetric dynamics. (author)

Supersymmetric leptogenesis with a light hidden sector

International Nuclear Information System (INIS)

De Simone, Andrea

2010-04-01

Supersymmetric scenarios incorporating thermal leptogenesis as the origin of the observed matter-antimatter asymmetry generically predict abundances of the primordial elements which are in conflict with observations. In this paper we pro- pose a simple way to circumvent this tension and accommodate naturally ther- mal leptogenesis and primordial nucleosynthesis. We postulate the existence of a light hidden sector, coupled very weakly to the Minimal Supersymmetric Standard Model, which opens up new decay channels for the next-to-lightest supersymmetric particle, thus diluting its abundance during nucleosynthesis. We present a general model-independent analysis of this mechanism as well as two concrete realizations, and describe the relevant cosmological and astrophysical bounds and implications for this dark matter scenario. Possible experimental signatures at colliders and in cosmic-ray observations are also discussed. (orig.)

Four-loop critical exponents for the Gross-Neveu-Yukawa models

International Nuclear Information System (INIS)

Zerf, Nikolai; Mihaila, Luminita N.; Herbut, Igor F.; Scherer, Michael M.

2017-09-01

We study the chiral Ising, the chiral XY and the chiral Heisenberg models at four-loop order with the perturbative renormalization group in 4-ε dimensions and compute critical exponents for the Gross-Neveu-Yukawa fixed points to order O(ε 4 ). Further, we provide Pade estimates for the correlation length exponent, the boson and fermion anomalous dimension as well as the leading correction to scaling exponent in 2+1 dimensions. We also confirm the emergence of supersymmetric field theories at four loops for the chiral Ising and the chiral XY models with N=1/4 and N=1/2 fermions, respectively. Furthermore, applications of our results relevant to various quantum transitions in the context of Dirac and Weyl semimetals are discussed, including interaction-induced transitions in graphene and surface states of topological insulators.

Four-loop critical exponents for the Gross-Neveu-Yukawa models

Energy Technology Data Exchange (ETDEWEB)

Zerf, Nikolai; Mihaila, Luminita N. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Marquard, Peter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Herbut, Igor F. [Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Physics; Scherer, Michael M. [Koeln Univ. (Germany). Inst. for Theoretical Physics

2017-09-15

We study the chiral Ising, the chiral XY and the chiral Heisenberg models at four-loop order with the perturbative renormalization group in 4-ε dimensions and compute critical exponents for the Gross-Neveu-Yukawa fixed points to order O(ε{sup 4}). Further, we provide Pade estimates for the correlation length exponent, the boson and fermion anomalous dimension as well as the leading correction to scaling exponent in 2+1 dimensions. We also confirm the emergence of supersymmetric field theories at four loops for the chiral Ising and the chiral XY models with N=1/4 and N=1/2 fermions, respectively. Furthermore, applications of our results relevant to various quantum transitions in the context of Dirac and Weyl semimetals are discussed, including interaction-induced transitions in graphene and surface states of topological insulators.

Duality and supersymmetric monopoles

International Nuclear Information System (INIS)

Gauntlett, J.P.

1998-01-01

Exact duality in supersymmetric gauge theories leads to highly non-trivial predictions about the moduli spaces of BPS monopole solutions. These notes attempt to be a pedagogical review of the current status of these investigations. (orig.)

The transformations between N= 2 supersymmetric Korteweg-de Vries and Harry Dym equations

International Nuclear Information System (INIS)

Tian Kai; Liu, Q. P.

2012-01-01

The N= 2 supercomformal transformations are employed to study supersymmetric integrable systems. It is proved that two known N= 2 supersymmetric Harry Dym equations are transformed into two N= 2 supersymmetric modified Korteweg-de Vries equations, thus are connected with two N= 2 supersymmetric Korteweg-de Vries equations.

Symmetries of supersymmetric integrable hierarchies of KP type

International Nuclear Information System (INIS)

Nissimov, E.; Pacheva, S.

2002-01-01

This article is devoted to the systematic study of additional (non-isospectral) symmetries of constrained (reduced) supersymmetric integrable hierarchies of KP type--the so-called SKP (R;M B ,M F ) models. The latter are supersymmetric extensions of ordinary constrained KP hierarchies which contain as special cases basic integrable systems such as (m)KdV, AKNS, Fordy-Kulish, Yajima-Oikawa, etc. As a first main result it is shown that any SKP (R;M B ,M F ) hierarchy possesses two different mutually (anti-)commuting types of superloop superalgebra additional symmetries corresponding to the positive- and negative-grade parts of certain superloop superalgebras. The second main result is the systematic construction of the full algebra of additional Virasoro symmetries of SKP (R;M B ,M F ) hierarchies, which requires nontrivial modifications of the Virasoro flows known from the general case of unconstrained Manin-Radul super-KP hierarchies (the latter flows do not define symmetries for constrained SKP (R;M B ,M F ) hierarchies). As a third main result we provide systematic construction of the supersymmetric analogs of multi-component (matrix) KP hierarchies and show that the latter contain, among others, the supersymmetric version of the Davey-Stewartson system. Finally, we present an explicit derivation of the general Darboux-Baecklund solutions for the SKP (R;M B ,M F ) super-tau functions (supersymmetric 'soliton'-like solutions) which preserve the additional (non-isospectral) symmetries

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.

Dispersive and damping properties of supersymmetric sound. 2

International Nuclear Information System (INIS)

Lebedev, V.V.; Smilga, A.V.

1988-01-01

This paper is the second part of the work devoted to the massless fermionic collective excitation in supersymmetric media at nonzero temperature. The solution to generalized kinetic equations for the Wess-Zumino model at low temperatures is presented and the situation at high temperatures is discussed. Supersymmetric gauge models are also discussed

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...

Supersymmetric self-dual Yang-Mills fields

International Nuclear Information System (INIS)

Zhao Liu

1994-01-01

A new four dimensional (4d) N = 1 supersymmetric integrable model, i.e. the supersymmetric self-dual Yang-Mills model is constructed. The equations of motion for this model are shown to be equivalent to the zero curvature condition on some superplane in the 4d superspace, the superplane being characterized by a point in the project space CP 3,4 . The linear systems are established according to this geometrical interpretation, and the effective action is also proposed in order to explain the dynamical content of the model

Gravitational quantum corrections in warped supersymmetric brane worlds

International Nuclear Information System (INIS)

Gregoire, T.; Rattazzi, R.; Scrucca, C.A.; Strumia, A.; Trincherini, E.

2005-01-01

We study gravitational quantum corrections in supersymmetric theories with warped extra dimensions. We develop for this a superfield formalism for linearized gauged supergravity. We show that the 1-loop effective Kahler potential is a simple functional of the KK spectrum in the presence of generic localized kinetic terms at the two branes. We also present a simple understanding of our results by showing that the leading matter effects are equivalent to suitable displacements of the branes. We then apply this general result to compute the gravity-mediated universal soft mass m 0 2 in models where the visible and the hidden sectors are sequestered at the two branes. We find that the contributions coming from radion mediation and brane-to-brane mediation are both negative in the minimal set-up, but the former can become positive if the gravitational kinetic term localized at the hidden brane has a sizable coefficient. We then compare the features of the two extreme cases of flat and very warped geometry, and give an outlook on the building of viable models

Supersymmetric axial anomalies and the Wess-Zumino action

International Nuclear Information System (INIS)

Harada, K.; Shizuya, K.

1988-01-01

We derive, by an algebraic method, a manifestly supersymmetric extension of Bardeen's minimal form of axial anomalies, which obeys the Wess-Zumino consistency condition. The left-right symmetric form of the anomalies is also obtained by a reduction procedure. We construct the supersymmetric Wess-Zumino effective action and study its low-energy features. (orig.)

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 ...

Dark matter asymmetry in supersymmetric Dirac leptogenesis

International Nuclear Information System (INIS)

Choi, Ki-Young; Chun, Eung Jin; Shin, Chang Sub

2013-01-01

We discuss asymmetric or symmetric dark matter candidate in the supersymmetric Dirac leptogenesis scenario. By introducing a singlet superfield coupling to right-handed neutrinos, the overabundance problem of dark matter can be evaded and various possibilities for dark matter candidate arise. If the singlino is the lightest supersymmetric particle (LSP), it becomes naturally asymmetric dark matter. On the other hand, the right-handed sneutrino is a symmetric dark matter candidate whose relic density can be determined by the usual thermal freeze-out process. The conventional neutralino or gravitino LSP can be also a dark matter candidate as its non-thermal production from the right-handed sneutrino can be controlled appropriately. In our scenario, the late-decay of heavy supersymmetric particles mainly produces the right-handed sneutrino and neutrino which is harmless to the standard prediction of the Big-Bang Nucleosynthesis

Supersymmetric models with light higgsinos

International Nuclear Information System (INIS)

Bruemmer, F.

2012-05-01

In the Minimal Supersymmetric Standard Model, the higgsinos can have masses around the electroweak scale, while the other supersymmetric particles have TeV-scale masses. This happens in models of gauge-mediated SUSY breaking with a high messenger scale, which are motivated from string theory. For particular choices of the messenger eld content, multi-TeV squark and gluino masses naturally lead to a much lower electroweak scale, somewhat similar to focus point supersymmetry. They also induce Higgs masses of 124-126 GeV, while making the discovery of supersymmetry at the LHC unlikely. The light higgsinos will be di cult to see at the LHC but may eventually be discovered at a linear collider.

Spontaneous baryogenesis in supersymmetric models

International Nuclear Information System (INIS)

Abel, S.A.; Cottingham, W.N.; Whittingham, I.B.

1993-01-01

In this paper we extent the results of previous work on spontaneous baryogenesis to general models involving charge-parity (CP) violation in the Higgs sector. We show how to deal with Chern-Simons terms appearing in the effective potential arising from phase changes in the vacuum expectation values of the Higgs fields. In particular, this enables us to apply this mechanism to general supersymmetric models including the minimal supersymmetric standard model, and the extended model with a gauge singlet. A comparison is made between this approach, and that in which one solves the equations of motion for Higgs winding modes. As anticipated in earlier work, the effect of the latter approach is found to be small. (Author)

Level comparison theorems and supersymmetric quantum mechanics

International Nuclear Information System (INIS)

Baumgartner, B.; Grosse, H.

1986-01-01

The sign of the Laplacian of the spherical symmetric potential determines the order of energy levels with the same principal Coulomb quantum number. This recently derived theorem has been generalized, extended and applied to various situations in particle, nuclear and atomic physics. Besides a comparison theorem the essential step was the use of supersymmetric quantum mechanics. Recently worked out applications of supersymmetric quantum mechanics to index problems of Dirac operators are mentioned. (Author)

1/N perturbation theory and quantum conservation laws for supersymmetrical chiral field. 2

International Nuclear Information System (INIS)

Aref'eva, I.Ya.; Krivoshchekov, V.K.; Medvedev, P.B.; Gosudarstvennyj Komitet Standartov Soveta Ministrov SSSR, Moscow; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Teoreticheskoj i Ehksperimental'noj Fiziki)

1980-01-01

The renormalizability of the supersymmetric chiral model (supersymmetric nonlinear σ-model) is proved in the framework of the 1/N perturbation theory expansion proposed in the previous paper. The renormalizability proof is essentially based on the quantum supersymmetric chirality condition. The supersymmetric formulation of equations of motion is given. The first non-trivial quantum conservation laws are derived

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}.

Supersymmetric extensions of Schrodinger-invariance

International Nuclear Information System (INIS)

Henkel, Malte; Unterberger, Jeremie

2006-01-01

The set of dynamic symmetries of the scalar free Schrodinger equation in d space dimensions gives a realization of the Schrodinger algebra that may be extended into a representation of the conformal algebra in d+2 dimensions, which yields the set of dynamic symmetries of the same equation where the mass is not viewed as a constant, but as an additional coordinate. An analogous construction also holds for the spin-12 Levy-Leblond equation. An N=2 supersymmetric extension of these equations leads, respectively, to a 'super-Schrodinger' model and to the (3 vertical bar 2)-supersymmetric model. Their dynamic supersymmetries form the Lie superalgebras osp(2 vertical bar 2)-bar sh(2 vertical bar 2) and osp(2 vertical bar 4), respectively. The Schrodinger algebra and its supersymmetric counterparts are found to be the largest finite-dimensional Lie subalgebras of a family of infinite-dimensional Lie superalgebras that are systematically constructed in a Poisson algebra setting, including the Schrodinger-Neveu-Schwarz algebra sns (N) with N supercharges. Covariant two-point functions of quasiprimary superfields are calculated for several subalgebras of osp(2 vertical bar 4). If one includes both N=2 supercharges and time-inversions, then the sum of the scaling dimensions is restricted to a finite set of possible values

Supersymmetric U boson and the old U(1) problem

International Nuclear Information System (INIS)

Kim, B.R.

1983-01-01

In the supersymmetric SU(3)xSU(2)xU(1)xUsup(')(1) model the new gauge group Usup(')(1) enforces the introduction of mirror fermions. In this note we address the inverse question. If one starts with SU(3)xSU(2)xU(1) including mirror fermions, what physical arguments other than the supersymmetric require the introduction of a new gauge group Usup(')(1). It turns out that the old U(1) problem is closely related with this question. Further we give an estimate for the upper bound for the parameter of the supersymmetric U boson r and x. (orig.)

Flavour changing decays of Z0 in supersymmetric models

International Nuclear Information System (INIS)

Gamberini, G.; Ridolfi, G.

1987-01-01

The possible existence of detectable flavour-changing branching modes of the Z 0 boson is examined in the context of supersymmetric models of currrent interest. An explicit calculation shows that in the so-called minimal version of the supersymmetric standard model the branching ratios for Z 0 →banti s or tanti c are not larger than in the standard model itself and are as such unobservable. On the contrary, we find that in a recently proposed extension of the supersymmetric standard model the mode Z 0 →tanti c may be at the order of being detectable. (orig.)

Supersymmetric deformations of 3D SCFTs from tri-Sasakian truncation

Energy Technology Data Exchange (ETDEWEB)

Karndumri, Parinya [Chulalongkorn University, String Theory and Supergravity Group, Department of Physics, Faculty of Science, Bangkok (Thailand)

2017-02-15

We holographically study supersymmetric deformations of N = 3 and N = 1 superconformal field theories in three dimensions using four-dimensional N = 4 gauged supergravity coupled to three-vector multiplets with non-semisimple SO(3) x (T{sup 3},T{sup 3}) gauge group. This gauged supergravity can be obtained from a truncation of 11-dimensional supergravity on a tri-Sasakian manifold and admits both N = 1,3 supersymmetric and stable non-supersymmetric AdS{sub 4} critical points. We analyze the BPS equations for SO(3) singlet scalars in detail and study possible supersymmetric solutions. A number of RG flows to non-conformal field theories and half-supersymmetric domain walls are found, and many of them can be given analytically. Apart from these ''flat'' domain walls, we also consider AdS{sub 3}-sliced domain wall solutions describing two-dimensional conformal defects with N = (1,0) supersymmetry within the dual N = 1 field theory while this type of solutions does not exist in the N = 3 case. (orig.)

Master integrals for the four-loop Sudakov form factor

International Nuclear Information System (INIS)

Boels, Rutger; Kniehl, Bernd A.; Yang, Gang; Chinese Academy of Sciences, Beijing

2015-08-01

The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally (N=4) supersymmetric Yang-Mills theory (SYM) in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. Probably the simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was obtained in integrand form in a previous work for N=4 SYM, up to a single parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP) identities using (a tweaked version of) Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. The appearing master integrals are cross-checked using algebraic techniques explored in the Mint package. The latter results provide the basis of master integrals applicable to generic form factors, including those in Quantum Chromodynamics. Remaining bottlenecks to completing the computation of the four-loop non-planar cusp anomalous dimension in N=4 SYM and beyond are identified.

SUSY non-Abelian gauge models: exact beta function from one loop of perturbation theory

International Nuclear Information System (INIS)

Shifman, M.A.; Vajnshtejn, A.I.; Zakharov, V.I.

1985-01-01

The method for calculating the exact β function (to all orders in the coupling constant) proposed earlier in supersymmetric electrodynamics is extended. The starting point is the observation that the low-energy effective action is exhausted by one loop provided that the theory is regularized supersymmetrically both in the ultraviolet and infrared domains in four dimensions. The Pouli-Villars method of the ultraviolet regularization is used. Two methods for the infrared regularization are considered. The first one - quantization in a box with a finite volume L 3 - is universally applicable to anygauge theory. The second method is based on the effective Higgs mechanism for mass generation and requires the presence of certain matter superfields in the lagrangian. Within this method the necessary condition is the existence of flat directions, so called valeys, along which the vacuum energy vanishes. The theory is quantized near epsilon non-vanishing value of the scalar field from the bottom of the valley. After calculating the one-loop effective action one and the same exact expression is obtained for the β function within the both approaches, and it also coincides with our earlier result extracted from instanton calculus. A few remarks on the problem of anomalies in SUSY gauge theories are presented

Supersymmetric symplectic quantum mechanics

Science.gov (United States)

de Menezes, Miralvo B.; Fernandes, M. C. B.; Martins, Maria das Graças R.; Santana, A. E.; Vianna, J. D. M.

2018-02-01

Symplectic Quantum Mechanics SQM considers a non-commutative algebra of functions on a phase space Γ and an associated Hilbert space HΓ to construct a unitary representation for the Galilei group. From this unitary representation the Schrödinger equation is rewritten in phase space variables and the Wigner function can be derived without the use of the Liouville-von Neumann equation. In this article we extend the methods of supersymmetric quantum mechanics SUSYQM to SQM. With the purpose of applications in quantum systems, the factorization method of the quantum mechanical formalism is then set within supersymmetric SQM. A hierarchy of simpler hamiltonians is generated leading to new computation tools for solving the eigenvalue problem in SQM. We illustrate the results by computing the states and spectra of the problem of a charged particle in a homogeneous magnetic field as well as the corresponding Wigner function.

Aspects of the supersymmetric Goldstone formalism

International Nuclear Information System (INIS)

Lerche, W.

1985-01-01

The present thesis deal with the discussion of general properties of Goldstone excitations in global N=1 supersymmetric theories. The results can become relevant in the framework of theories which interpret quarks and leptons as composite 'quasi-Goldstone fermions'. The thesis is arranged in two main parts: the first is occupied by group-theoretical aspects, i.e. by the spectrum of supersymmetric Goldstone excitations as well as by geometrical considerations which are connected with effective Lagrangian densities. In the second main part dynamic questions like for instance mass generation are treated. For this a suitable formalism is developed. (orig.) [de

Two-loop Higgs mass calculations beyond the MSSM with SARAH and SPheno

Energy Technology Data Exchange (ETDEWEB)

Nickel, Kilian [Physikalisches Institut, Universitaet Bonn (Germany); Staub, Florian [Theory Division, CERN, Geneva (Switzerland); Goodsell, Mark [LPTHE, UPMC Univ. Paris 06 (France)

2015-07-01

We present a recent extension to the Mathematica package SARAH which allows for Higgs mass calculations at the two-loop level in a wide range of supersymmetric models beyond the MSSM. These calculations are based on the effective potential approach. For the numerical evaluation Fortran code for SPheno is generated by SARAH. This allows to predict the Higgs mass in more complicated SUSY theories with a similar precision as most state-of-the-art spectrum generators do for the MSSM.

Supersymmetric reflection matrices

International Nuclear Information System (INIS)

Moriconi, M.; Schoutens, K.

1997-04-01

We briefly review the general structure of integrable particle theories in 1 + 1 dimensions having N = 1 supersymmetry. Examples are specific perturbed superconformal field theories (of Yang-Lee type) and the N = 1 supersymmetric sine-Gordon theory. We comment on the modifications that are required when the N = 1 supersymmetry algebra contains non-trivial topological charges. (author). 8 refs, 2 figs

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…

Non-perturbative supersymmetry anomaly in supersymmetric QCD

International Nuclear Information System (INIS)

Shamir, Y.

1991-03-01

The zero modes of the Dirac operator in an instanton and other topologically non-trivial backgrounds are unstable in a large class of massless or partially massless supersymmetric gauge theories. We show that under a generic perturbation of the scalar fields all zero modes become resonances, and discuss the ensuing breakdown of conventional perturbation theory. As a result, despite of the presence of massless fermions, the field theoretic tunneling amplitude is not suppressed. In massless supersymmetric QCD with N c ≤ N f the effective potential is found to be negative and monotonically increasing in the weak coupling regime for scalar VEVs which lie on the perturbatively flat directions. Consequently, massless supersymmetric QCD with N c ≤ N f exhibits a non-perturbative supersymmetry anomaly and exists in a strongly interacting phase which closely resembles ordinary QCD. The same conclusions apply if small masses are added to the lagrangian and the massless limit is smooth. (author). 21 refs, 5 figs

Two- and three dimensional electrons and photons and their supersymmetric partners

International Nuclear Information System (INIS)

Steringa, J.J.

1989-01-01

This thesis contains a study of supersymmetric gauge theories in two and tree spacetime dimensions. Supersymmetric gauge theories in less than four spacetime dimensions are useful for trying out field theoretical methods which ultimately will be applied to realistic models. In ch. 1 all the aspects of field theory that are necessary for later chapters are treated. In ch. 2 sypersymmetry in two- and three-dimensional space time is treated, and superfields and superspace techniques are introduced. With these a simple Abelian supersymmetric gauge theory in two spacetime dimensions is constructed, the Schwinger model. Ch. 3 deals with general properties and a perturbative analysis of the model. Ch. 4 contains a non-perturbative analysis by means of Dyson-Schwinger equations. A supersummetric extension of theSalam-Delbourgo Gauge Technique is presented and is applied with some seccess to the supersymmetric Schwinger model. In ch. 5 prperties of three-dimensional supersymmetric gauge theories are investigated. (author). 55 refs.; 7 figs.; schemes

Invariant solutions of the supersymmetric sine-Gordon equation

International Nuclear Information System (INIS)

Grundland, A M; Hariton, A J; Snobl, L

2009-01-01

A comprehensive symmetry analysis of the N=1 supersymmetric sine-Gordon equation is performed. Two different forms of the supersymmetric system are considered. We begin by studying a system of partial differential equations corresponding to the coefficients of the various powers of the anticommuting independent variables. Next, we consider the super-sine-Gordon equation expressed in terms of a bosonic superfield involving anticommuting independent variables. In each case, a Lie (super)algebra of symmetries is determined and a classification of all subgroups having generic orbits of codimension 1 in the space of independent variables is performed. The method of symmetry reduction is systematically applied in order to derive invariant solutions of the supersymmetric model. Several types of algebraic, hyperbolic and doubly periodic solutions are obtained in explicit form.

Globally and locally supersymmetric effective theories for light fields

International Nuclear Information System (INIS)

Brizi, Leonardo; Gomez-Reino, Marta; Scrucca, Claudio A.

2009-01-01

We reconsider the general question of how to characterize most efficiently the low-energy effective theory obtained by integrating out heavy modes in globally and locally supersymmetric theories. We consider theories with chiral and vector multiplets and identify the conditions under which an approximately supersymmetric low-energy effective theory can exist. These conditions translate into the requirements that all the derivatives, fermions and auxiliary fields should be small in units of the heavy mass scale. They apply not only to the matter sector, but also to the gravitational one if present, and imply in that case that the gravitino mass should be small. We then show how to determine the unique exactly supersymmetric theory that approximates this effective theory at the lowest order in the counting of derivatives, fermions and auxiliary fields, by working both at the superfield level and with component fields. As a result we give a simple prescription for integrating out heavy superfields in an algebraic and manifestly supersymmetric way, which turns out to hold in the same form both for globally and locally supersymmetric theories, meaning that the process of integrating out heavy modes commutes with the process of switching on gravity. More precisely, for heavy chiral and vector multiplets one has to impose respectively stationarity of the superpotential and the Kaehler potential.

Indirect detection of heavy supersymmetric dark matter

International Nuclear Information System (INIS)

Kamionkowski, M.

1991-02-01

If neutralinos reside in the galactic halo they will be captured in the Sun and annihilate therein producing high-energy neutrinos. Present limits on the flux of such neutrinos from underground detectors such as IMB and Kamiokande 2 may be used to rule out certain supersymmetric dark-matter candidates, while in many other supersymmetric models the rates are large enough that if neutralinos do reside in the galactic halo, observation of a neutrino signal may be possible in the near future. 10 refs., 2 figs

(4,0) supersymmetric sigma-model and t-duality

International Nuclear Information System (INIS)

Lhallabi, T.

1997-08-01

The conserved supercurrents J ++ and J -- are deduced for the (4,0) supersymmetric sigma model on harmonic superspace with arbitrary background gauge connection. These are introduced in the Lagrangian density of the model by their couplings to the analytic gauge superfields Γ -- and Γ ++ . The T-duality transformations are obtained by integrating out the analytic gauge superfields. Finally the (4,0) supersymmetric anomaly is derived. (author). 20 refs

Three-body Supersymmetric Top Decays

CERN Document Server

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

2000-01-01

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

Extended N=2 supersymmetric matrix (1, s)-KdV hierarchies

International Nuclear Information System (INIS)

Krivonos, S.O.; Sorin, A.S.

1997-01-01

We propose the Lax operators for N=2 supersymmetric matrix generalization of the bosonic (1, s)-KdV hierarchies. The simplest examples - the N=2 supersymmetric a=4 KdV and a=5/2 Boussinesq hierarchies - are discussed in detail

On the stochastic structure of globally supersymmetric field theories

International Nuclear Information System (INIS)

Flume, R.; Lechtenfeld, O.

1983-09-01

We reformulate the bosonic sector of globally supersymmetric field theories through a ''fermionisation'' of bosonic Feynman graphs. The recipe for the fermionisation gives an explicit realisation of the Nicolai map. The graphical rules for supersymmetric Yang-Mills fields in the reformulated version turn out to be simpler than those of ordinary Yang-Mills fields. (orig.)

One-instanton calculations in N=2 supersymmetric gauge theories

International Nuclear Information System (INIS)

Ito, Katsushi

1998-01-01

We study the low-energy effective action of N=2 supersymmetric gauge theories in the Coulomb branch. Using microscopic instanton calculus, we compute the one-instanton contribution to the pre potential for N=2 supersymmetric SU(N c ) Yang-Mills theory. We show that the microscopic result agrees with the exact solution. (Author). 23 refs

On the supersymmetrization of Galileon theories in four dimensions

Science.gov (United States)

Elvang, Henriette; Hadjiantonis, Marios; Jones, Callum R. T.; Paranjape, Shruti

2018-06-01

We use on-shell amplitude techniques to study the possible N = 1 supersymmetrizations of Galileon theories in 3 + 1 dimensions, both in the limit of decoupling from DBI and without. Our results are that (1) the quartic Galileon has a supersymmetrization compatible with Galileon shift symmetry (ϕ → ϕ + c +bμxμ) for the scalar sector and a constant shift symmetry (ψ → ψ + ξ) for the fermion sector, and it is unique at least at 6th order in fields, but possibly not beyond; (2) the enhanced "special Galileon" symmetry is incompatible with supersymmetry; (3) there exists a quintic Galileon with a complex scalar preserving Galileon shift symmetry; (4) one cannot supersymmetrize the cubic and quintic Galileon while preserving the Galileon shift symmetry for the complex scalar; and (5) for the quartic and quintic Galileon, we present evidence for a supersymmetrization in which the real Galileon scalar is partnered with an R-axion to form a complex scalar which only has an ordinary shift symmetry.

Classifying supersymmetric solutions in 3D maximal supergravity

Science.gov (United States)

de Boer, Jan; Mayerson, Daniel R.; Shigemori, Masaki

2014-12-01

String theory contains various extended objects. Among those, objects of codimension two (such as the D7-brane) are particularly interesting. Codimension-two objects carry non-Abelian charges which are elements of a discrete U-duality group and they may not admit a simple spacetime description, in which case they are known as exotic branes. A complete classification of consistent codimension-two objects in string theory is missing, even if we demand that they preserve some supersymmetry. As a step toward such a classification, we study the supersymmetric solutions of 3D maximal supergravity, which can be regarded as an approximate description of the geometry near codimension-two objects. We present a complete classification of the types of supersymmetric solutions that exist in this theory. We found that this problem reduces to that of classifying nilpotent orbits associated with the U-duality group, for which various mathematical results are known. We show that the only allowed supersymmetric configurations are 1/2, 1/4, 1/8, and 1/16 BPS, and determine the nilpotent orbits that they correspond to. One example of 1/16 BPS configurations is a generalization of the MSW system, where momentum runs along the intersection of seven M5-branes. On the other hand, it turns out exceedingly difficult to translate this classification into a simple criterion for supersymmetry in terms of the non-Abelian (monodromy) charges of the objects. For example, it can happen that a supersymmetric solution exists locally but cannot be extended all the way to the location of the object. To illustrate the various issues that arise in constructing supersymmetric solutions, we present a number of explicit examples.

Supersymmetric Higgs boson production in Z decays

International Nuclear Information System (INIS)

Gamberini, G.; Giudice, G.F.; Ridolfi, G.

1987-01-01

The problem of distinguishing between the standard model and the supersymmetric Higgs bosons is considered in the context of Z 0 decays. We find that, for some choices of the parameters, the branching ratio for Z 0 → H 0 γ is strongly enhanced by the exchange of supersymmetric fermions as virtual particles. This makes the study of this process at LEP very interesting, since other Z 0 branching modes into Higgs bosons, such as Z 0 → H 0 μ + μ - , are not so clearly modified by supersymmetry. (orig.)

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...

Contraction-based classification of supersymmetric extensions of kinematical lie algebras

International Nuclear Information System (INIS)

Campoamor-Stursberg, R.; Rausch de Traubenberg, M.

2010-01-01

We study supersymmetric extensions of classical kinematical algebras from the point of view of contraction theory. It is shown that contracting the supersymmetric extension of the anti-de Sitter algebra leads to a hierarchy similar in structure to the classical Bacry-Levy-Leblond classification.

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.

N = 1 supersymmetric indices and the four-dimensional A-model

Science.gov (United States)

Closset, Cyril; Kim, Heeyeon; Willett, Brian

2017-08-01

We compute the supersymmetric partition function of N = 1 supersymmetric gauge theories with an R-symmetry on M_4\\cong M_{g,p}× {S}^1 , a principal elliptic fiber bundle of degree p over a genus- g Riemann surface, Σ g . Equivalently, we compute the generalized supersymmetric index I_{M}{_{g,p}, with the supersymmetric three-manifold M_{g,p} as the spatial slice. The ordinary N = 1 supersymmetric index on the round three-sphere is recovered as a special case. We approach this computation from the point of view of a topological A-model for the abelianized gauge fields on the base Σ g . This A-model — or A-twisted two-dimensional N = (2 , 2) gauge theory — encodes all the information about the generalized indices, which are viewed as expectations values of some canonically-defined surface defects wrapped on T 2 inside Σ g × T 2. Being defined by compactification on the torus, the A-model also enjoys natural modular properties, governed by the four-dimensional 't Hooft anomalies. As an application of our results, we provide new tests of Seiberg duality. We also present a new evaluation formula for the three-sphere index as a sum over two-dimensional vacua.

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...

Lepton radiative decays in supersymmetric standard model

International Nuclear Information System (INIS)

Volkov, G.G.; Liparteliani, A.G.

1988-01-01

Radiative decays of charged leptons l i →l j γ(γ * ) have been discussed in the framework of the supersymmetric generalization of the standard model. The most general form of the formfactors for the one-loop vertex function is written. Decay widths of the mentioned radiative decays are calculated. Scalar lepton masses are estimated at the maximal mixing angle in the scalar sector proceeding from the present upper limit for the branching of the decay μ→eγ. In case of the maximal mixing angle and the least mass degeneration of scalar leptons of various generations the following lower limit for the scalar electron mass m e-tilde >1.5 TeV has been obtained. The mass of the scalar neutrino is 0(1) TeV, in case the charged calibrino is lighter than the scalar neutrino. The result obtained sensitive to the choice of the lepton mixing angle in the scalar sector, namely, in decreasing the value sin 2 θ by an order of magnitude, the limitation on the scalar electron mass may decrease more than 3 times. In the latter case the direct observation of electrons at the e + e - -collider (1x1 TeV) becomes available

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.

Supersymmetric Higgs bosons and beyond

International Nuclear Information System (INIS)

Carena, Marcela; Kong, Kyoungchul; Ponton, Eduardo; Zurita, Jose

2010-01-01

We consider supersymmetric models that include particles beyond the minimal supersymmetric standard model (MSSM) with masses in the TeV range, and that couple significantly to the MSSM Higgs sector. We perform a model-independent analysis of the spectrum and couplings of the MSSM Higgs fields, based on an effective theory of the MSSM degrees of freedom. The tree-level mass of the lightest CP-even state can easily be above the LEP bound of 114 GeV, thus allowing for a relatively light spectrum of superpartners, restricted only by direct searches. The Higgs spectrum and couplings can be significantly modified compared to the MSSM ones, often allowing for interesting new decay modes. We also observe that the gluon fusion production cross section of the SM-like Higgs can be enhanced with respect to both the standard model and the MSSM.

IIB solutions with N>28 Killing spinors are maximally supersymmetric

International Nuclear Information System (INIS)

Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

2007-01-01

We show that all IIB supergravity backgrounds which admit more than 28 Killing spinors are maximally supersymmetric. In particular, we find that for all N>28 backgrounds the supercovariant curvature vanishes, and that the quotients of maximally supersymmetric backgrounds either preserve all 32 or N<29 supersymmetries

arXiv B-branes and supersymmetric quivers in 2d

CERN Document Server

Closset, Cyril; Sharpe, Eric

2018-02-08

We study 2d $ \\mathcal{N} $ = (0, 2) supersymmetric quiver gauge theories that describe the low-energy dynamics of D1-branes at Calabi-Yau fourfold (CY$_{4}$) singularities. On general grounds, the holomorphic sector of these theories — matter content and (classical) superpotential interactions — should be fully captured by the topological B-model on the CY$_{4}$. By studying a number of examples, we confirm this expectation and flesh out the dictionary between B-brane category and supersymmetric quiver: the matter content of the supersymmetric quiver is encoded in morphisms between B-branes (that is, Ext groups of coherent sheaves), while the superpotential interactions are encoded in the A$_{∞}$ algebra satisfied by the morphisms. This provides us with a derivation of the supersymmetric quiver directly from the CY$_{4}$ geometry. We also suggest a relation between triality of $ \\mathcal{N} $ = (0,2) gauge theories and certain mutations of exceptional collections of sheaves. 0d $ \\mathcal{N} $ = 1 supe...

Supersymmetric versions of the Fokas–Gel’fand formula for immersion

International Nuclear Information System (INIS)

Bertrand, S; Grundland, A M

2016-01-01

In this paper, we construct and investigate two supersymmetric versions of the Fokas–Gel’fand formula for the immersion of 2D surfaces associated with a supersymmetric integrable system. The first version involves an infinitesimal deformation of the zero-curvature condition and the linear spectral problem associated with this system. This deformation leads the surfaces to be represented in terms of a bosonic supermatrix immersed in a Lie superalgebra. The second supersymmetric version is obtained by using a fermionic parameter deformation to construct surfaces expressed in terms of a fermionic supermatrix immersed in a Lie superalgebra. For both extensions, we provide a geometrical characterization of deformed surfaces using the super Killing form as an inner product and a super moving frame formalism. The theoretical results are applied to the supersymmetric sine-Gordon equation in order to construct super soliton surfaces associated with five different symmetries. We find integrated forms of these surfaces which represent constant Gaussian curvature surfaces and nonlinear Weingarten-type surfaces. (paper)

Basic hypergeometry of supersymmetric dualities

Energy Technology Data Exchange (ETDEWEB)

Gahramanov, Ilmar, E-mail: ilmar.gahramanov@aei.mpg.de [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, D14476 Potsdam (Germany); Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Grossen Windkanal 6, D12489 Berlin (Germany); Institute of Radiation Problems ANAS, B.Vahabzade 9, AZ1143 Baku (Azerbaijan); Department of Mathematics, Khazar University, Mehseti St. 41, AZ1096, Baku (Azerbaijan); Rosengren, Hjalmar, E-mail: hjalmar@chalmers.se [Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg, SE-412 96 Göteborg (Sweden)

2016-12-15

We introduce several new identities combining basic hypergeometric sums and integrals. Such identities appear in the context of superconformal index computations for three-dimensional supersymmetric dual theories. We give both analytic proofs and physical interpretations of the presented identities.

Algebraic renormalization of supersymmetric gauge theories with dimensionful parameters

International Nuclear Information System (INIS)

Golterman, Maarten; Shamir, Yigal

2010-01-01

It is usually believed that there are no perturbative anomalies in supersymmetric gauge theories beyond the well-known chiral anomaly. In this paper we revisit this issue, because previously given arguments are incomplete. Specifically, we rule out the existence of soft anomalies, i.e., quantum violations of supersymmetric Ward identities proportional to a mass parameter in a classically supersymmetric theory. We do this by combining a previously proven theorem on the absence of hard anomalies with a spurion analysis, using the methods of algebraic renormalization. We work in the on-shell component formalism throughout. In order to deal with the nonlinearity of on-shell supersymmetry transformations, we take the spurions to be dynamical, and show how they nevertheless can be decoupled.

Generalized supersymmetric cosmological term in N=1 supergravity

Energy Technology Data Exchange (ETDEWEB)

Concha, P.K.; Rodríguez, E.K. [Departamento de Física, Universidad de Concepción,Casilla 160-C, Concepción (Chile); Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino,Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Torino,Via Pietro Giuria 1, 10125 Torino (Italy); Salgado, P. [Departamento de Física, Universidad de Concepción,Casilla 160-C, Concepción (Chile)

2015-08-04

An alternative way of introducing the supersymmetric cosmological term in a supergravity theory is presented. We show that the AdS-Lorentz superalgebra allows to construct a geometrical formulation of supergravity containing a generalized supersymmetric cosmological constant. The N=1, D=4 supergravity action is built only from the curvatures of the AdS-Lorentz superalgebra and corresponds to a MacDowell-Mansouri like action. The extension to a generalized AdS-Lorentz superalgebra is also analyzed.

Renormalization of supersymmetric gauge theories on orbifolds: Brane gauge couplings and higher derivative operators

International Nuclear Information System (INIS)

Groot Nibbelink, Stefan; Hillenbach, Mark

2005-01-01

We consider supersymmetric gauge theories coupled to hypermultiplets on five- and six-dimensional orbifolds and determine the bulk and local fixed point renormalizations of the gauge couplings. We infer from a component analysis that the hypermultiplet does not induce renormalization of the brane gauge couplings on the five-dimensional orbifold S 1 /Z 2 . This is not due to supersymmetry, since the bosonic and fermionic contributions cancel separately. We extend this investigation to T 2 /Z N orbifolds using supergraph techniques in six dimensions. On general Z N orbifolds the gauge couplings do renormalize at the fixed points, except for the Z 2 fixed points of even ordered orbifolds. To cancel the bulk one-loop divergences a dimension six higher derivative operator is needed, in addition to the standard bulk gauge kinetic term.

N=4 supersymmetric Yang Mills scattering amplitudes at high energies. The Regge cut contribution

International Nuclear Information System (INIS)

Bartels, J.; Sabio Vera, A.

2008-07-01

We further investigate, in N=4 supersymmetric Yang Mills theories, the high energy Regge behavior of six-point scattering amplitudes. In particular, for the new Regge cut contribution found in our previous paper, we compute in the leading logarithmic approximation (LLA) the energy spectrum of the BFKL equation in the color octet channel, and we calculate explicitly the two loop corrections to the discontinuities of the amplitudes for the transitions 2→4 and 3→3. We find an explicit solution of the BFKL equation for the octet channel for arbitrary momentum transfers and investigate the intercepts of the Regge singularities in this channel. As an important result we find that the universal collinear and infrared singularities of the BDS formula are not affected by this Regge-cut contribution. (orig.)

Aspects of supersymmetric inflation

International Nuclear Information System (INIS)

Lindblom, P.R.

1987-01-01

A new supersymmetric inflationary model is presented and shown to possess the following features: a successful slow rollover produced by quantum corrections; an acceptable pattern of supersymmetry breaking leading to the correct value of the electroweak scale; and a stable slow rollover transition to a minimum with vanishing cosmological constant. It is demonstrated that there is a class of GUT models which are compatible with an inflationary universe scenario in which: (a) the GUT and inflationary phase transitions are distinct (as in supersymmetric inflation); and (b) an observable number of GUT monopoles are created thermally due to reheating of the GUT sector after inflation. This provides one of the few ways of reconciling an observation of GUT monopoles with inflation. New techniques are developed for constructing inflationary models with multiple inflation fields, such as generalizing the one-dimensional slow rollover constraints and estimating the contribution to δρ/ρ from fluctuations transverse to the path of the slow rollover. A new method for ending the slow rollover portion of the inflationary transition is developed

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…

Two-dimensional nonlinear equations of supersymmetric gauge theories

International Nuclear Information System (INIS)

Savel'ev, M.V.

1985-01-01

Supersymmetric generalization of two-dimensional nonlinear dynamical equations of gauge theories is presented. The nontrivial dynamics of a physical system in the supersymmetry and supergravity theories for (2+2)-dimensions is described by the integrable embeddings of Vsub(2/2) superspace into the flat enveloping superspace Rsub(N/M), supplied with the structure of a Lie superalgebra. An equation is derived which describes a supersymmetric generalization of the two-dimensional Toda lattice. It contains both super-Liouville and Sinh-Gordon equations

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.