Results for "Stefan Liebler"

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Off-shell effects in Higgs decays to heavy gauge bosons and signal-background interference in Higgs decays to photons at a linear colliderMar 26 2015We discuss off-shell contributions in Higgs decays to heavy gauge bosons $H\rightarrow VV^{(*)}$ with $V\in\lbrace Z,W\rbrace$ for a standard model (SM) Higgs boson for both dominant production processes $e^+e^-\rightarrow ZH\rightarrow ZVV^{(*)}$ and ... More
Neutral Higgs production at proton colliders in the CP-conserving NMSSMFeb 27 2015May 21 2015We discuss neutral Higgs boson production through gluon fusion and bottom-quark annihilation in the CP-conserving $\mathbb{Z}_3$-invariant Next-to-Minimal Supersymmetric Standard Model (NMSSM) at proton colliders. For gluon fusion we adapt known asymptotic ... More
Electroweak corrections to Neutralino and Chargino decays into a W-boson in the (N)MSSMNov 29 2010Dec 06 2011We present the complete electroweak one-loop corrections to the partial widths for two-body decays of a chargino (neutralino) into a W-boson and a neutralino (chargino). We perform the calculation for the minimal and the next-to-minimal supersymmetric ... More
On-shell renormalization of neutralino and chargino mass matrices in R-parity violating models - Correlation between LSP decays and neutrino mixing angles revisitedJun 15 2011Dec 06 2011We present an on-shell renormalization scheme for the neutralino and chargino mass matrices for two R-parity violating models, namely bilinear R-parity violation and the munuSSM with one right-handed neutrino superfield. We discuss in both models how ... More
Generic calculation of two-body partial decay widths at the full one-loop levelMar 27 2017Oct 24 2017We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson ... More
MSSM Higgs Benchmark Scenarios for Run 2 and Beyond: the low $\tanβ$ regionJan 17 2019Mar 27 2019We propose two new benchmark scenarios for Higgs-boson searches in the Minimal Supersymmetric Standard Model (MSSM). These scenarios are specifically designed for the low $\tan\beta$ region. A light Higgs-boson mass prediction compatible with the observed ... More
CP violation in bilinear R-parity violation and its consequences for the early universeJun 30 2014Supersymmetric models with bilinear R-parity violation (BRpV) provide a framework for neutrino masses and mixing angles to explain neutrino oscillation data. We consider CP violation within the new physical phases in BRpV and discuss their effect on the ... More
SusHi: A program for the calculation of Higgs production in gluon fusion and bottom-quark annihilation in the Standard Model and the MSSMDec 13 2012Mar 19 2013This article describes the code SusHi (for "Supersymmetric Higgs") which calculates the cross sections $pp/p\bar{p}\rightarrow\phi+X$ in gluon fusion and bottom-quark annihilation in the SM and the MSSM, where $\phi$ is any of the neutral Higgs bosons ... More
SusHi Bento: Beyond NNLO and the heavy-top limitMay 10 2016Version 1.6.0 of the code SusHi is presented. Concerning inclusive CP-even Higgs production in gluon fusion, the following new features with respect to previous versions have been implemented: expansion of the partonic cross section in the soft limit, ... More
SusHi Bento: Beyond NNLO and the heavy-top limitMay 10 2016Nov 28 2016Version 1.6.0 of the code SusHi is presented. Concerning inclusive CP-even Higgs production in gluon fusion, the following new features with respect to previous versions have been implemented: expansion of the partonic cross section in the soft limit, ... More
Phenomenology of on-shell Higgs production in the MSSM with complex parametersNov 28 2016A computation of inclusive cross sections for the production of neutral Higgs bosons through gluon fusion and bottom-quark annihilation is presented in the MSSM with complex parameters. The predictions for the gluon-fusion process are based on an explicit ... More
Interference contributions to gluon initiated heavy Higgs production in the Two-Higgs-Doublet ModelDec 22 2015Mar 08 2016We discuss the production of a heavy neutral Higgs boson of a CP-conserving Two-Higgs-Doublet Model in gluon fusion and its decay into a four-fermion final state, $gg (\rightarrow VV) \rightarrow e^+e^-\mu^+\mu^-/e^+e^-\nu_l\bar\nu_l$. We investigate ... More
$pp\to A\to Zh$ and the wrong-sign limit of the Two-Higgs-Doublet ModelOct 31 2017Mar 07 2018We point out the importance of the decay channels $A\to Zh$ and $H\to VV$ in the wrong-sign limit of the Two-Higgs-Doublet Model (2HDM) of type II. They can be the dominant decay modes at moderate values of $\tan\beta$, even if the (pseudo)scalar mass ... More
Light Stop Mass Limits from Higgs Rate Measurements in the MSSM: Is MSSM Electroweak Baryogenesis Still Alive After All?Dec 30 2015We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the second, heavy ... More
Higgs Strahlung at the Large Hadron Collider in the 2-Higgs-Doublet ModelJul 30 2013Jun 16 2014We present a calculation of all relevant contributions to associated production of a Higgs boson with a weak gauge boson in the 2-Higgs-Doublet Model (2HDM) at the LHC, $pp \rightarrow V\phi$, with $\phi\in\{h,H^0,A\}$ and $V\in\{W,Z\}$. While for the ... More
MSSM Higgs Benchmark Scenarios for Run 2 and Beyond: the low $\tanβ$ regionJan 17 2019We propose two new benchmark scenarios for Higgs-boson searches in the Minimal Supersymmetric Standard Model (MSSM). These scenarios are specifically designed for the low $\tan\beta$ region. A light Higgs-boson mass prediction compatible with the observed ... More
Distributions for neutral Higgs production in the NMSSMAug 09 2016A novel computation of the fully-differential cross section for neutral Higgs-boson production through gluon fusion in the CP-conserving NMSSM is presented. Based on the calculation of NLO corrections to the total cross section [1], we implemented the ... More
Off-shell effects in Higgs processes at a linear collider and implications for the LHCFeb 27 2015Jun 23 2015The importance of off-shell contributions is discussed for $H\to VV^{(*)}$ with $V\in\{Z,W\}$ for large invariant masses $m_{VV}$ involving a standard model (SM)-like Higgs boson with $m_H=125$GeV at a linear collider (LC). Both dominant production processes ... More
Phenomenology of on-shell Higgs production in the MSSM with complex parametersNov 28 2016Nov 06 2017A computation of inclusive cross sections for neutral Higgs boson production through gluon fusion and bottom-quark annihilation is presented in the MSSM with complex parameters. The predictions for the gluon-fusion process are based on an explicit calculation ... More
$\mathcal{CP}$-violating effects on MSSM Higgs searchesJan 16 2018We study the effects of $\mathcal{CP}$-violating phases on the phenomenology of the Higgs sector of the MSSM. Complex parameters in the MSSM lead to $\mathcal{CP}$-violating mixing between the tree-level $\mathcal{CP}$-even and $\mathcal{CP}$-odd neutral ... More
Probing the top-quark width through ratios of resonance contributions of $e^+e^-\rightarrow W^+W^-b\bar{b}$Nov 07 2015We exploit offshell regions in the process $e^+e^-\rightarrow W^+W^-b\bar{b}$ to gain access to the top-quark width. Working at next-to-leading order in QCD we show that carefully selected ratios of offshell regions to onshell regions in the reconstructed ... More
The hMSSM approach for Higgs self-couplings revisitedOct 25 2018Jan 31 2019We compare the decay of the heavy Higgs boson into two SM-like Higgs bosons, $H\to hh$, calculated in a Feynman-diagrammatic approach at the one-loop level based on the one hand on the full effective potential involving the top quark and stops in the ... More
vh@nnlo-v2: New physics in Higgs StrahlungFeb 13 2018Introducing version 2 of the code vh@nnlo, we study the effects of a number of new-physics scenarios on the Higgs-Strahlung process. In particular, the cross section is evaluated within a general 2HDM and the MSSM. While the Drell-Yan-like contributions ... More
vh@nnlo-v2: New physics in Higgs StrahlungFeb 13 2018May 14 2018Introducing version 2 of the code vh@nnlo, we study the effects of a number of new-physics scenarios on the Higgs-Strahlung process. In particular, the cross section is evaluated within a general 2HDM and the MSSM. While the Drell-Yan-like contributions ... More
Phenomenology of the inflation-inspired NMSSM at the electroweak scaleSep 19 2018Jan 31 2019The concept of Higgs inflation can be elegantly incorporated in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). A linear combination of the two Higgs-doublet fields plays the role of the inflaton which is non-minimally coupled to gravity. This ... More
Phenomenological consequences of Higgs inflation in the NMSSM at the electroweak scaleNov 30 2018The Next-to-Minimal Supersymmetric Standard Model (NMSSM) can incorporate inflation, where a combination of the Higgs-doublet fields plays the role of the inflaton. At the high scale, the Higgs doublets are non-minimally coupled to supergravity; this ... More
Exploiting jet binning to identify the initial state of high-mass resonancesMay 19 2016Sep 30 2016If a new high-mass resonance is discovered at the Large Hadron Collider, model-independent techniques to identify the production mechanism will be crucial to understand its nature and effective couplings to Standard Model particles. We present a powerful ... More
MSSM Higgs Boson Searches at the LHC: Benchmark Scenarios for Run 2 and BeyondAug 22 2018We propose six new benchmark scenarios for Higgs boson searches in the Minimal Supersymmetric Standard Model. Our calculations follow the recommendations of the LHC Higgs Cross Section Working Group, and benefit from recent developments in the predictions ... More
Reliability of regulatory networks and its evolutionMay 27 2008The problem of reliability of the dynamics in biological regulatory networks is studied in the framework of a generalized Boolean network model with continuous timing and noise. Using well-known artificial genetic networks such as the repressilator, we ... More
Reliability of genetic networks is evolvableJul 10 2007Control of the living cell functions with remarkable reliability despite the stochastic nature of the underlying molecular networks -- a property presumably optimized by biological evolution. We here ask to what extent the property of a stochastic dynamical ... More
On Semigroups of Two-Dimensional Upper-Triangular Integer MatricesMay 13 2019We analyze algorithmic problems in finitely generated semigroups of two-dimensional upper-triangular integer matrices. These semigroup problems are tightly connected with problems about compositions of affine functions over one variable. Building on a ... More
Finite-Size Corrections for Ground States of Edwards-Anderson Spin GlassesOct 28 2011May 30 2012Extensive computations of ground state energies of the Edwards-Anderson spin glass on bond-diluted, hypercubic lattices are conducted in dimensions d=3,..,7. Results are presented for bond-densities exactly at the percolation threshold, p=p_c, and deep ... More
Superstability of the yeast cell cycle dynamics: Ensuring causality in the presence of biochemical stochasticityMay 05 2006Gene regulatory dynamics is governed by molecular processes and therefore exhibits an inherent stochasticity. However, for the survival of an organism it is a strict necessity that this intrinsic noise does not prevent robust functioning of the system. ... More
Interactive Natural Language Acquisition in a Multi-modal Recurrent Neural ArchitectureMar 24 2017Feb 07 2018For the complex human brain that enables us to communicate in natural language, we gathered good understandings of principles underlying language acquisition and processing, knowledge about socio-cultural conditions, and insights about activity patterns ... More
Weak Limit of the 3-State Quantum Walk on the LineApr 04 2014May 21 2014We revisit the one dimensional discrete time quantum walk with 3 states and the Grover coin. We derive analytic expressions for observed the localization, an long time approximation for the probability density function (PDF). We also connect the time ... More
Streaming KernelizationMay 06 2014Kernelization is a formalization of preprocessing for combinatorially hard problems. We modify the standard definition for kernelization, which allows any polynomial-time algorithm for the preprocessing, by requiring instead that the preprocessing runs ... More
On the commutability of homogenization and linearization in finite elasticityNov 16 2010May 16 2011We study non-convex elastic energy functionals associated to (spatially) periodic, frame indifferent energy densities with a single non-degenerate energy well at SO(n). Under the assumption that the energy density admits a quadratic Taylor expansion at ... More
The H-Covariant Strong Picard GroupoidSep 08 2004Apr 25 2005The notion of H-covariant strong Morita equivalence is introduced for *-algebras over C = R(i) with an ordered ring R which are equipped with a *-action of a Hopf *-algebra H. This defines a corresponding H-covariant strong Picard groupoid which encodes ... More
A shortcut to (sun)flowers: Kernels in logarithmic space or linear timeApr 30 2015We investigate whether kernelization results can be obtained if we restrict kernelization algorithms to run in logarithmic space. This restriction for kernelization is motivated by the question of what results are attainable for preprocessing via simple ... More
The generating of Fractal Images Using MathCAD ProgramMar 24 2009This paper presents the graphic representation in the z-plane of the first three iterations of the algorithm that generates the Sierpinski Gasket. It analyzes the influence of the f(z) map when we represent fractal images.
Projection methods for ill-posed problems revisitedJul 13 2015The discretization of least-squares problems for linear ill-posed operator equations in Hilbert spaces is considered. The main subject of this article concerns conditions for convergence of the associated discretized minimum-norm least-squares solution ... More
Twisted Reidemeister torsion, the Thurston norm and fibered manifoldsJan 29 2013We prove that the twisted Reidemeister torsion of a 3-manifold corresponding to a fibered class is monic and we show that it gives lower bounds on the Thurston norm. The former fixes a flawed proof in [FV10], the latter gives a quick alternative argument ... More
Reidemeister torsion, the Thurston norm and Harvey's invariantsAug 31 2005Feb 25 2006Recently twisted and higher order Alexander polynomials were used by Cochran, Harvey, Friedl--Kim and Turaev to give lower bounds on the Thurston norm. We first show how Reidemeister torsion relates to these Alexander polynomials. We then give lower bounds ... More
A Hidden Signal in the Ulam sequenceJul 01 2015Jul 06 2016The Ulam sequence is defined as $a_1 =1, a_2 = 2$ and $a_n$ being the smallest integer that can be written as the sum of two distinct earlier elements in a unique way. This gives $$1, 2, 3, 4, 6, 8, 11, 13, 16, 18, 26, 28, 36, 38, 47, \dots$$ Ulam remarked ... More
New Bounds for the Traveling Salesman ConstantNov 25 2013Mar 27 2014Let $X_1, X_2, \dots, X_n$ be independent and uniformly distributed random variables in the unit square $[0,1]^2$ and let $L(X_1, \dots, X_n)$ be the length of the shortest traveling salesman path through these points. In 1959, Beardwood, Halton $\&$ ... More
Nonextensive statistical mechanics and complex scale-free networksSep 07 2006One explanation for the impressive recent boom in network theory might be that it provides a promising tool for an understanding of complex systems. Network theory is mainly focusing on discrete large-scale topological structures rather than on microscopic ... More
Aging Exponents in Self-Organized CriticalityJun 11 1997Aug 07 1997In a recent Letter [Phys. Rev. Lett. 79, 889 (1997) and cond-mat/9702054] we have demonstrated that the avalanches in the Bak-Sneppen model display aging behavior similar to glassy systems. Numerical results for temporal correlations show a broad distribution ... More
Stiffness of the Edwards-Anderson Model in all DimensionsAug 01 2005Sep 23 2005A comprehensive description in all dimensions is provided for the scaling exponent $y$ of low-energy excitations in the Ising spin glass introduced by Edwards and Anderson. A combination of extensive numerical as well as theoretical results suggest that ... More
Neutron skin thickness of heavy nuclei with $α$-particle correlations and the slope of the nuclear symmetry energyMar 12 2014Jun 16 2014The formation of $\alpha$-particle clusters on the surface of heavy nuclei is described in a generalized relativistic mean-field model with explicit cluster degrees of freedom. The effects on the size of the neutron skin of Sn nuclei and ${}^{208}$Pb ... More
Fermions and the scattering equationsDec 18 2014Mar 03 2015This paper investigates how tree-level amplitudes with massless quarks, gluons and/or massless scalars transforming under a single copy of the gauge group can be expressed in the context of the scattering equations as a sum over the inequivalent solutions ... More
The SISCone jet algorithm optimised for low particle multiplicitiesAug 09 2011Dec 10 2011The SISCone jet algorithm is a seedless infrared-safe cone jet algorithm. There exists an implementation which is highly optimised for a large number of final state particles. However, in fixed-order perturbative calculations with a small number of final ... More
Does one need the O(epsilon)- and O(epsilon^2)-terms of one-loop amplitudes in an NNLO calculation ?Jul 26 2011Sep 12 2011This article discusses the occurences of one-loop amplitudes within a next-to-next-to-leading order calculation. In an NNLO calculation the one-loop amplitude enters squared and one would therefore naively expect that the O(epsilon)- and O(epsilon^2)-terms ... More
Automated calculations for multi-leg processesJul 23 2007Jul 26 2007The search for signals of new physics at the forthcoming LHC experiments involves the analysis of final states characterised by a high number of hadronic jets or identified particles. Precise theoretical predictions for these processes require the computation ... More
Hopf algebra structures in particle physicsOct 14 2003In the recent years, Hopf algebras have been introduced to describe certain combinatorial properties of quantum field theories. I will give a basic introduction to these algebras and review some occurrences in particle physics.
Moments of event shapes in electron-positron annihilation at NNLOSep 28 2009Nov 10 2009This article gives the perturbative NNLO results for the moments of the most commonly used event shape variables associated to three-jet events in electron-positron annihilation: Thrust, heavy jet mass, wide jet broadening, total jet broadening, C parameter ... More
Introduction to Monte Carlo methodsJun 23 2000These lectures given to graduate students in high energy physics, provide an introduction to Monte Carlo methods. After an overview of classical numerical quadrature rules, Monte Carlo integration together with variance-reducing techniques is introduced. ... More
Calculational techniques (not only) for single top productionMay 29 2000A next-to-leading order calculation for single top production including spin-dependent observables requires efficient techniques for the calculation of the relevant loop amplitudes. We discuss the adaption of dimensional regularization, the spinor helicity ... More
Coherent states and geodesics: cut locus and conjugate locusFeb 22 1995Sep 15 1995The intimate relationship between coherent states and geodesics is pointed out. For homogenous manifolds on which the exponential from the Lie algebra to the Lie group equals the geodesic exponential, and in particular for symmetric spaces, it is proved ... More
Symmetry Dependence of Localization in Quasi- 1- dimensional Disordered WiresMar 26 2000Jun 25 2000The crossover in energy level statistics of a quasi-1-dimensional disordered wire as a function of its length L is used, in order to derive its averaged localization length, without magnetic field, in a magnetic field and for moderate spin orbit scattering ... More
Indirect Detection of Dark Matter with gamma raysOct 10 2013Feb 12 2014The details of what constitutes the majority of the mass that makes up dark matter in the Universe remains one of the prime puzzles of cosmology and particle physics today - eighty years after the first observational indications. Today, it is widely accepted ... More
Status of the NLO Corrections to the Photon Impact FactorJun 20 2002We present the status of the programme of calculating the next-to-leading order corrections to the virtual photon impact factor. In particular, we discuss new results for the transversely polarized photon. We briefly outline the definition of infrared ... More
Herwig++ for e+e- collisionsAug 03 2004Some results obtained with the new Monte Carlo event generator Herwig++ are presented. In its first version (1.0), Herwig++ is capable of simulating e+e- Annihilation events. We discuss its relevance for future e+e- colliders and show results on the multiplicity ... More
From Unified Theories to Precision Neutrino ExperimentsAug 31 2006The expected high sensitivities of future neutrino oscillation experiments will allow precision tests of unified theories of flavour. In order to compare GUT scale predictions for neutrino masses, leptonic mixing angles and CP violating phases with experimental ... More
On Polynomial Kernels for Integer Linear Programs: Covering, Packing and FeasibilityFeb 14 2013Feb 15 2013We study the existence of polynomial kernels for the problem of deciding feasibility of integer linear programs (ILPs), and for finding good solutions for covering and packing ILPs. Our main results are as follows: First, we show that the ILP Feasibility ... More
On Polynomial Kernels for Sparse Integer Linear ProgramsFeb 14 2013Feb 15 2013Integer linear programs (ILPs) are a widely applied framework for dealing with combinatorial problems that arise in practice. It is known, e.g., by the success of CPLEX, that preprocessing and simplification can greatly speed up the process of optimizing ... More
Polynomial Kernelizations for MIN F^+Pi_1 and MAX NPFeb 11 2009Dec 13 2011It has been observed in many places that constant-factor approximable problems often admit polynomial or even linear problem kernels for their decision versions, e.g., Vertex Cover, Feedback Vertex Set, and Triangle Packing. While there exist examples ... More
The asymptotic rank of metric spacesJan 08 2007Oct 20 2008In this article we define and study a notion of asymptotic rank for metric spaces and show in our main theorem that for a large class of spaces, the asymptotic rank is characterized by the growth of the higher filling functions. For a proper, cocompact, ... More
Nilpotent groups without exactly polynomial Dehn functionApr 16 2010We prove super-quadratic lower bounds for the growth of the filling area function of a certain class of Carnot groups. This class contains groups for which it is known that their Dehn function grows no faster than $n^2\log n$. We therefore obtain the ... More
Expectation bubbles in a spin model of markets: Intermittency from frustration across scalesMay 10 2001May 16 2001A simple spin model is studied, motivated by the dynamics of traders in a market where expectation bubbles and crashes occur. The dynamics is governed by interactions which are frustrated across different scales: While ferromagnetic couplings connect ... More
Measurement of the production cross section for W- and Z-bosons in association with jets in ATLASJun 10 2011We report on the measurements of inclusive W+jets and Z+jets cross sections in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the bosons, are presented as a function of ... More
Theta divisors with curve summands and the Schottky problemSep 10 2014Aug 25 2015We prove the following converse of Riemann's Theorem: let (A,\Theta) be an indecomposable principally polarized abelian variety whose theta divisor can be written as a sum of a curve and a codimension two subvariety \Theta=C+Y. Then C is smooth, A is ... More
A causal perspective on random geometryMay 02 2009In this thesis we investigate the importance of causality in non-perturbative approaches to quantum gravity. Firstly, causal sets are introduced as a simple kinematical model for causal geometry. It is shown how causal sets could account for the microscopic ... More
Hyperon-nucleon interaction and baryonic contact terms in SU(3) chiral effective field theoryDec 16 2013In this proceeding we summarize results for baryonic contact terms derived within SU(3) chiral effective field theory. The four-baryon contact terms, necessary for the description of the hyperon-nucleon interaction, include SU(3) symmetric and explicit ... More
Density of states near the Mott-Hubbard transition in the limit of large dimensionsMar 12 1998Oct 30 1998The zero temperature Mott-Hubbard transition as a function of the Coulomb repulsion U is investigated in the limit of large dimensions. The behavior of the density of states near the transition at U=U_c is analyzed in all orders of the skeleton expansion. ... More
A model of semimetallic behavior in strongly correlated electron systemsNov 17 1998Metals with values of the resistivity and the Hall coefficient much larger than typical ones, e.g., of sodium, are called semimetals. We suggest a model for semimetals which takes into account the strong Coulomb repulsion of the charge carriers, especially ... More
Phenomenological guide to physics beyond the Standard ModelFeb 14 2005Various aspects of physics beyond the Standard Model are discussed from the perspective of the fantastic phenomenological success of the Standard Model, its simplicity and predictive power
Status of the Minimal Supersymmetric Standard ModelOct 04 1995Recent results in study of the Minimal Supersymmetric Standard Model as the effective low energy theory give important hints for experimental search for supersymmetry. Also, in the bottom-up approach to explore weak scale - GUT scale connection, they ... More
The Kaon B-parameter in quenched QCDOct 02 2005I report on a recent determination by the ALPHA collaboration of the kaon B-parameter using lattice QCD with Wilson type quarks. An effort is made to control all systematic errors except for the quenched approximation. The preliminary result for the renormalization ... More
Non-perturbative Renormalization in Lattice Field TheoryNov 27 2000I review the strategies which have been developped in recent years to solve the non-perturbative renormalization problem in lattice field theories. Although the techniques are general, the focus will be on applications to lattice QCD. I discuss the momentum ... More
The Schrodinger functional with chirally rotated boundary conditionsNov 16 2005Using orbifold techniques I construct the Schrodinger functional (SF) for a doublet of Wilson quarks with chirally rotated boundary conditions. This allows to perform checks of universality: for instance, the renormalized SF coupling constant, defined ... More
Data Unfolding Methods in High Energy PhysicsNov 07 2016A selection of unfolding methods commonly used in High Energy Physics is compared. The methods discussed here are: bin-by-bin correction factors, matrix inversion, template fit, Tikhonov regularisation and two examples of iterative methods. Two procedures ... More
The semiclassical small-$\hbar$ limit of loci of roots of fundamental solutions for polynomial potentialsMay 04 2008Dec 15 2008In this paper a description of the small-$\hbar$ limit of loci of zeros of fundamental solutions for polynomial potentials is given. The considered cases of the potentials are bounded to the ones which provided us with simple turning points only. Among ... More
New opportunities with spectro-interferometry and spectro-astrometryDec 15 2013Latest-generation spectro-interferometric instruments combine a milliarcsecond angular resolution with spectral capabilities, resulting in an immensely increased information content. Here, I present methodological work and results that illustrate the ... More
A Common View on Strong, Uniform, and Other Notions of Equivalence in Answer-Set ProgrammingDec 06 2007Logic programming under the answer-set semantics nowadays deals with numerous different notions of program equivalence. This is due to the fact that equivalence for substitution (known as strong equivalence) and ordinary equivalence are different concepts. ... More
A generalized likelihood ratio test statistic for Cherenkov telescope dataDec 04 2011Jun 15 2012Astrophysical sources of TeV gamma rays are usually established by Cherenkov telescope observations. These counting type instruments have a field of view of few degrees in diameter and record large numbers of particle air showers via their Cherenkov radiation ... More
Power correction analyses in e+e- annihilationSep 29 2000The current status of theoretical work and experimental analyses on power corrections in QCD for e+e- annihilation will be reviewed. Measurements of the number of active quark flavours n_f and the QCD colour factors C_A and C_F derived from QCD fits to ... More
Deformations of WZW modelsDec 17 2003Jan 12 2004Current-current deformations for WZW models of semisimple compact groups are discussed in a sigma model approach. We start with the abelian rank one group U(1). Afterwards, we keep the rank one but allow for non abelian structures by considering SU(2). ... More
Gauging Flavour in Meta-Stable Susy Breaking ModelsAug 04 2006Aug 16 2006We modify the first ISS model (hep-th/0602239) by gauging a diagonal flavour symmetry. We add additional multiplets transforming as fundamentals and anti-fundamentals under the gauged flavour group. Their number is chosen such that the microscopic theory ... More
Strings, Branes and Extra DimensionsOct 05 2001Jan 03 2002This review is devoted to strings and branes. Firstly, perturbative string theory is introduced. The appearance of various types of branes is discussed. These include orbifold fixed planes, D-branes and orientifold planes. The connection to BPS vacua ... More
Polarization-anisotropy induced spatial anisotropy of polariton amplification in planar semiconductor microcavitiesNov 05 2007Based on a microscopic many-particle theory we investigate the amplification of polaritons in planar semiconductor microcavities. We study a spatially perfectly isotropic microcavity system and excitation geometry. For this system, our analysis shows ... More
Implementation and Evaluation of multimodal input/output channels for task-based industrial robot programmingMar 17 2015Programming industrial robots is not very intuitive, and the programmer has to be a domain expert for e.g. welding and programming to know how the task is optimally executed. For SMEs such employees are not affordable, nor cost-effective. Therefore a ... More
Lectures on configuration space methods for sunrise-type diagramsJul 23 2003In this lecture series I will give a fundamental insight into configuration space techniques which are of help to calculate a broad class of Feynman diagrams, the sunrise-type diagrams. Applications are shown along with basic concepts and techniques.
Analyzing QCD Sum Rules for Heavy Baryons at Next-to-Leading Order in α_SOct 15 1997In this talk I consider QCD sum rules for the ground state heavy baryons to leading order in $1/m_Q$ and at next-to-leading order in $\alpha_S$ within the context of Heavy Quark Symmetry. The analysis is done at a fixed scale $\mu=1 GeV$. The evolution ... More
The Quantum Query Complexity of Elliptic PDEDec 27 2005The complexity of the following numerical problem is studied in the quantum model of computation: Consider a general elliptic partial differential equation of order 2m in a smooth, bounded domain Q\subset \R^d with smooth coefficients and homogeneous ... More
A remark on the Chisini conjectureJan 20 2000The Chisini conjecture asserts that a generic ramified covering over the complex projective plane of degree at least 5 is uniquely determined by its branch curve. We prove this for degree at least 12 using the work of Kulikov (math-AG/9803144).
On the Stokes matrices of the $tt^*$-Toda equationOct 01 2016We derive a formula for the signature of the symmetrized Stokes matrix $\cal{S}+\cal{S}^\mathrm{T}$ for the $tt^*$-Toda equation. As a corollary, we verify a conjecture of Cecotti and Vafa regarding when $\cal{S}+\cal{S}^\mathrm{T}$ is positive definite, ... More
Gaia - A White Dwarf Discovery MachineOct 30 2006The Gaia data will help to improve the construction of a luminosity function for the disk and the halo and will provide a more accurate determination of the age of our solar neighborhood. Moreover, reliable stellar dynamical investigations of the disk ... More
Gauge covariant heat kernel expansion at finite temperatureFeb 18 2003The heat kernel method is extended to the case of finite temperature. Special emphasis is given to the study of gauge theories. Due to the compactness of space in the Euclidean time direction (inverse temperature) the field strength cannot completely ... More
Resummation of soft modes in the free energy of Phi^4 theoryAug 26 1998Nov 24 1998A new method is proposed for the calculation of the free energy of an N-component Phi^4 theory at finite temperature. The method combines a perturbative treatment of the hard modes with a non-perturbative treatment in the effectively three-dimensional ... More
Diffusion of a Test Chain in a Quenched Background of Semidilute PolymersMar 03 1999Based on a recently established formalism (U. Ebert, J. Stat. Phys. 82, 183 (1996)) we analyze the diffusive motion of a long polymer in a quenched random medium. The medium is modeled by a frozen semidilute polymer system. In the framework of standard ... More