1,238 research outputs found

    Surface operators in 5d gauge theories and duality relations

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    We study half-BPS surface operators in 5d N=1 gauge theories compactified on a circle. Using localization methods and the twisted chiral ring relations of coupled 3d/5d quiver gauge theories, we calculate the twisted chiral superpotential that governs the infrared properties of these surface operators. We make a detailed analysis of the localization integrand, and by comparing with the results from the twisted chiral ring equations obtain constraints on the 3d and 5d Chern-Simons levels so that the instanton partition function does not depend on the choice of integration contour. For these values of the Chern-Simons couplings, we comment on how the distinct quiver theories that realize the same surface operator are related to each other by Aharony-Seiberg dualities.Comment: 39 pages. v2: A few sentences rephrased, references added, and typos corrected. Matches version published in JHE

    Non-perturbative studies of N=2 conformal quiver gauge theories

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    We study N=2 super-conformal field theories in four dimensions that correspond to mass-deformed linear quivers with n gauge groups and (bi-)fundamental matter. We describe them using Seiberg-Witten curves obtained from an M-theory construction and via the AGT correspondence. We take particular care in obtaining the detailed relation between the parameters appearing in these descriptions and the physical quantities of the quiver gauge theories. This precise map allows us to efficiently reconstruct the non-perturbative prepotential that encodes the effective IR properties of these theories. We give explicit expressions in the cases n=1,2, also in the presence of an Omega-background in the Nekrasov-Shatashvili limit. All our results are successfully checked against those of the direct microscopic evaluation of the prepotential a la Nekrasov using localization methods.Comment: 56 pages, 7 figures, PdfLaTeX. v2: a few references added, version to appear on Fortschritte der Physi

    Modular and duality properties of surface operators in N=2* gauge theories

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    We calculate the instanton partition function of the four-dimensional N=2* SU(N) gauge theory in the presence of a generic surface operator, using equivariant localization. By analyzing the constraints that arise from S-duality, we show that the effective twisted superpotential, which governs the infrared dynamics of the two-dimensional theory on the surface operator, satisfies a modular anomaly equation. Exploiting the localization results, we solve this equation in terms of elliptic and quasi-modular forms which resum all non-perturbative corrections. We also show that our results, derived for monodromy defects in the four-dimensional theory, match the effective twisted superpotential describing the infrared properties of certain two-dimensional sigma models coupled either to pure N=2 or to N=2* gauge theories.Comment: 51 pages, v3: references added, typos fixed, footnote added, some small changes in the text, appendix B streamlined. Matches the published versio

    CP--odd Correlation in the Decay of Neutral Higgs Boson into ZZZZ, W+WW^+W^-, or ttˉt{\bar t}

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    We investigate the possibility of detecting CP--odd angular correlations in the various decay modes of the neutral Higgs boson including the modes of a ZZZZ pair, a W+WW^+W^- pair, or a heavy quark pair. It is a natural way to probe the CP character of the Higgs boson once it is identified. Final state interactions (i.e. the absorptive decay amplitude) is not required in such correlations. As an illustrative example we take the fundamental source of the CP nonconservation to be in the Yukawa couplings of the Higgs boson to the heavy fermions. A similar correlation in the process e+el+lHe^+e^- \to l^+ l^- H is also proposed. Our analysis of these correlations will be useful for experiments in future colliders such as LEP II, SSC, LHC or NLC.Comment: 16 pages, plus 8 postscript graphs not posted befor

    Clustering in 18O - absolute determination of branching ratios via high-resolution particle spectroscopy

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    The determination of absolute branching ratios for high-energy states in light nuclei is an important and useful tool for probing the underlying nuclear structure of individual resonances: for example, in establishing the tendency of an excited state towards α -cluster structure. Difficulty arises in measuring these branching ratios due to similarities in available decay channels, such as ( 18 O, n ) and ( 18 O, 2 n ), as well as differences in geometric efficiencies due to population of bound excited levels in daughter nuclei. Methods are presented using Monte Carlo techniques to overcome these issues

    Biatrial Recurrence of Two Independently Growing Cardiac Myxoma in a Patient with Multiple Tumor Disease

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    We report the case of a 56-year-old female patient with biatrial recurrence of cardiac myxoma and extensive comorbidities. In the literature, only few cases of biatrial myxoma can be found and they generally describe a single tumor reaching both atria. We found two independently growing cardiac myxomas of both atria

    Study of nuclear structure of 13C and 20Ne by low energy nuclear reactions

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    We report some recent experimental results on the spectroscopy of 13C and 20Ne nuclei by means of low energy nuclear reactions carried out with high resolution electrostatic accelerators. In the case of 13C we investigated the possible existence of a-cluster states above the a emission threshold by means of low energy elastic resonant scattering α+9Be in direct kinematics. Excitation functions show the presence of various resonances that have been reproduced by R-matrix fit. We studied also the structure of 20Ne by means of the 19F(p,α0) reaction at sub-barrier energies. The spectroscopy of 20Ne excited states in the region Ex 13.5-14.0 MeV can be probed by analyzing experimental angular distributions and excitation functions. This reaction plays an important role also in the CNOF cycle and is an important ingredient to describe hydrogen-induced destruction of fluorine in massive stars. For this reason we investigated the trend of S-factor, that has been compared with results previously reported in the literature. © Published under licence by IOP Publishing Lt

    D-branes in Toroidal Orbifolds and Mirror Symmetry

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    We study D-branes extended in T^2/Z_4 using the mirror description as a tensor product of minimal models. We describe branes in the mirror both as boundary states in minimal models and as matrix factorizations in the corresponding Landau-Ginzburg model. We isolate a minimal set of branes and give a geometric interpretation of these as D1-branes constrained to the orbifold fixed points. This picture is supported both by spacetime arguments and by the explicit construction of the boundary states, adapting the known results for rational boundary states in the minimal models. Similar techniques apply to a larger class of toroidal orbifolds.Comment: 30 pages, 2 figure

    Matrix Factorizations and Homological Mirror Symmetry on the Torus

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    We consider matrix factorizations and homological mirror symmetry on the torus T^2 using a Landau-Ginzburg description. We identify the basic matrix factorizations of the Landau-Ginzburg superpotential and compute the full spectrum, taking into account the explicit dependence on bulk and boundary moduli. We verify homological mirror symmetry by comparing three-point functions in the A-model and the B-model.Comment: 41 pages, 9 figures, v2: reference added, minor corrections and clarifications, version published in JHE

    Determining the Structure of Higgs Couplings at the LHC

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    Higgs boson production via weak boson fusion at the CERN Large Hadron Collider has the capability to determine the dominant CP nature of a Higgs boson, via the tensor structure of its coupling to weak bosons. This information is contained in the azimuthal angle distribution of the two outgoing forward tagging jets. The technique is independent of both the Higgs boson mass and the observed decay channel.Comment: 5 pages, 4 figures, version accepted for publication in PR
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