Results for "W. Chalupczak"

total 64147took 0.13s
Parametric amplification and noise-squeezing in room temperature atomic vapoursMar 01 2019We report on the use of parametric excitation to coherently manipulate the collective spin state of an atomic vapour at room temperature. Signatures of the parametric excitation are detected in the ground-state spin evolution. These include the excitation ... More
Linear and non-linear coherent coupling in a Bell-Bloom magnetometerMar 13 2019Spin-exchange collisions in hot vapours are generally regarded as a decoherence mechanism. In contrast, we show that linear and non-linear spin-exchange coupling can lead to the generation of atomic coherence in a Bell-Bloom magnetometer. In particular, ... More
Cancellation of the collisional frequency shift in caesium fountain clocksDec 12 2006We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F = 4, mF = 0> atoms, depending on the initial cloud parameters. ... More
Non-destructive structural imaging of steelwork with atomic magnetometersAug 09 2018We demonstrate the imaging of ferromagnetic carbon steel samples and we detect the thinning of their profile with a sensitivity of 0.1 mm using a Cs radio-frequency atomic magnetometer. Images are obtained at room temperature, in magnetically unscreened ... More
Pairwise Comparisons Rating Scale ParadoxNov 24 2015Dec 01 2015This study demonstrates that incorrect data are entered into a pairwise comparisons matrix for processing into weights for the data collected by a rating scale. Unprocessed rating scale data lead to a paradox. A solution to it, based on normalization, ... More
Geometric relation between centrality and the impact parameter in relativistic heavy-ion collisionsOct 08 2001We show, under general assumptions which are well satisfied in relativistic heavy-ion collisions, that the geometric relation of centrality c to the impact parameter b, namely c ~ pi b^2/sigma_inel, holds to a very high accuracy for all but most peripheral ... More
In-Medium Modifications of Hadron Masses and Chemical Freeze-Out in Ultra-Relativistic Heavy-Ion CollisionsOct 06 1999We confront the hypothesis of chemical freeze-out in ultra-relativistic heavy-ion collisions with the hypothesis of large modifications of hadron masses in nuclear medium. We find that the thermal-model predictions for the ratios of particle multiplicities ... More
A Free Field Representation of the Osp(2|2) current algebra at level k=-2, and Dirac Fermions in a random SU(2) gauge potentialDec 11 2000The Osp(2|2) current algebra at level k=-2 is known to describe the IR fixed point of 2D Dirac fermions, subject to a random SU(2) gauge potential. We show that this theory has a simple free-field representation in terms of a compact, and a non-compact ... More
The Single-Electron-Box and the Helicity Modulus of an inverse square XY-ModelDec 19 1996We calculate the average number of electrons on a metallic single-electron-box as a function of the gate voltage for arbitrary values of the tunneling conductance. In the vicinity of the plateaus the problem is equivalent to calculating the helicity modulus ... More
Radiative capture of protons by deuteronsAug 17 1998Sep 03 1998The differential cross section for radiative capture of protons by deuterons is calculated using different realistic NN interactions. We compare our results with the available experimental data below $E_x = 20 MeV$. Excellent agreement is found when taking ... More
Triton photodisintegration with realistic potentialsDec 05 1997The photodisintegration of $^{3}$H is treated by means of coupled integral equations using separable versions of the Paris and the Bonn potentials in their kernel. The differential cross section for the inverse reaction is obtained via detailed balance. ... More
Topological phases: Classification of topological insulators and superconductors of non-interacting Fermions, and beyondDec 30 2015After briefly recalling the quantum entanglement-based view of topological phases of matter in order to outline the general context, we give an overview of different approaches to the classification problem of topological insulators and superconductors ... More
Large lepton flavour violating signals in supersymmetric particle decaysOct 24 2002We study lepton flavour violating signals at a future e+ e- linear collider within the general MSSM, allowing for the most general flavour structure. We demonstrate that there is a large region in parameter space with large signals, while being consistent ... More
Temperature-dependent quasiparticle band structure of the ferromagnetic semiconductor EuSJun 24 2002We present calculations for the temperature-dependent electronic structure of the ferromagnetic semiconductor EuS. A combination of a many-body evaluation of a multiband Kondo-lattice model and a first-principles T=0--bandstructure calculation (tight-binding ... More
Toponium as Nonabelian Positronium ?Jul 01 1993The expected large mass $m_t$ of the top quark provides for the first time a chance to discuss the bound-states of the corresponding quantum system as the nonabelian generalization of positronium, using the full power of relativistic quantum field theoretic ... More
Detecting Relic Gravitational Waves in the CMB: Comparison of Planck and Ground-based ExperimentsJul 09 2009We compare the detection abilities for the relic gravitational waves by two kinds of forthcoming cosmic microwave background radiation (CMB) experiments, space-based Planck satellite and the various ground-based experiments. Comparing with the ground-based ... More
Subtracted Dispersion Relations for In-Medium Meson Correlators in QCD Sum RulesJan 22 1999We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out the importance of scattering terms, as well as finite, well-defined subtraction constants. ... More
Low temperature thermodynamics of inverse square spin models in one dimensionApr 29 1998We present a field-theoretic renormalization group calculation in two loop order for classical O(N)-models with an inverse square interaction in the vicinity of their lower critical dimensionality one. The magnetic susceptibility at low temperatures is ... More
Photodisintegration of the triton with realistic potentialsDec 08 1997The process $\gamma + t \to n + d$ is treated by means of three-body integral equations employing in their kernel the W-Matrix representation of the subsystem amplitudes. As compared to the plane wave (Born) approximation the full solution of the integral ... More
Pac-Learning Recursive Logic Programs: Efficient AlgorithmsMay 01 1995We present algorithms that learn certain classes of function-free recursive logic programs in polynomial time from equivalence queries. In particular, we show that a single k-ary recursive constant-depth determinate clause is learnable. Two-clause programs ... More
Rigorous QCD-Potential for the $t\bar{t}$-System at ThresholdAug 02 1994Aug 04 1994Recent evidence for the top mass in the region of 160 $GeV$ for the first time provides an opportunity to use the full power of relativistic quantum field theoretical methods, available also for weakly bound systems. Because of the large decay width $\G$ ... More
Weak Coupling Limit and Genuine QCD Predictions for Heavy QuarkoniaAug 03 1994Although individual levels of toponium will be unobservable, the top--anti--top system near threshold fulfills all requirements of a rigorous perturbation theory in QCD for weakly bound systems. Corresponding techniques from positronium may thus be transferred ... More
A note on radial basis function computingJun 03 2001This note carries three purposes involving our latest advances on the radial basis function (RBF) approach. First, we will introduce a new scheme employing the boundary knot method (BKM) to nonlinear convection-diffusion problem. It is stressed that the ... More
A Monte Carlo Study of Pairwise ComparisonsMay 07 2015Consistent approximations obtained by geometric means ($GM$) and the principal eigenvector ($EV$), turned out to be close enough for 1,000,000 not-so-inconsistent pairwise comparisons matrices. In this respect both methods are accurate enough for most ... More
Moments of Isovector Quark Distributions in Lattice QCDOct 16 2002We investigate the connection of lattice calculations of moments of isovector parton distributions to the physical regime through extrapolations in the quark mass. We consider the one pion loop renormalisation of the nucleon matrix elements of the corresponding ... More
Parton distribution functions in the pion from lattice QCDMar 21 2003Jun 30 2003We analyze the moments of parton distribution functions in the pion calculated in lattice QCD, paying particular attention to their chiral extrapolation. Using the lowest three non-trivial moments calculated on the lattice, we assess the accuracy with ... More
Accretion disk wind in the AGN broad-line region: Spectroscopically resolved line profile variations in Mrk110Jun 19 2003Detailed line profile variability studies of the narrow line Seyfert 1 galaxy Mrk110 are presented. We obtained the spectra in a variability campaign carried out with the 9.2m Hobby-Eberly Telescope at McDonald Observatory. The integrated Balmer and Helium ... More
New differential equations in the six-vertex modelAug 19 2015Dec 14 2015This letter is concerned with the analysis of the six-vertex model with domain-wall boundaries in terms of partial differential equations (PDEs). The model's partition function is shown to obey a system of PDEs resembling the celebrated Knizhnik-Zamolodchikov ... More
Off-shell scalar products for the $XXZ$ spin chain with open boundariesDec 17 2014Jan 23 2015In this work we study scalar products of Bethe vectors associated with the $XXZ$ spin chain with open boundary conditions. The scalar products are obtained as solutions of a system of functional equations. The description of scalar products through functional ... More
On the elliptic $\mathfrak{gl}_2$ solid-on-solid model: functional relations and determinantsJun 20 2016In this work we study an elliptic solid-on-solid model with domain-wall boundaries having the elliptic quantum group $\mathcal{E}_{p, \gamma}[\widehat{\mathfrak{gl}_2}]$ as its underlying symmetry algebra. We elaborate on results previously presented ... More
Cancellations in Neutrinoless Double Beta Decay and the Neutrino Mass MatrixAug 04 2000Dec 19 2000In a degenerate scheme with mass m_0 a complete analysis of the allowed range of the effective electron neutrino Majorana mass <m> is performed. Special attention is paid to effects of cancellations caused either by intrinsic CP parities of the eigenstates ... More
Neutrino oscillation experiments and limits on lepton-number and lepton-flavor violating processesMar 15 2000Jun 19 2000Using a three neutrino framework we investigate bounds for the effective Majorana neutrino mass matrix. The mass measured in neutrinoless double beta decay is its (11) element. Lepton-number and -flavor violating processes sensitive to each element are ... More
The Mode-Coupling Theory of the Glass TransitionFeb 09 1997We give a brief introduction to the mode-coupling theory of the glass transition, a theory which was proposed a while ago to describe the dynamics of supercooled liquids. After presenting the basic equations of the theory, we review some of its predictions ... More
Low-energy sum rules and large-$N_c$ consistency conditionsFeb 02 1994The large-$N_c$ consistency conditions for axial vector and isovector magnetic couplings of pions to baryons are discussed from the point of view of low-energy current-algebra sum rules (Adler-Weisberger, Cabibbo-Radicati). In particular, we show how ... More
Nucleon structure at large x: nuclear effects in deuteriumJun 21 2010I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x -> 1. A new global study of parton distributions, using ... More
Flavor Asymmetries in the Proton and Semi-Inclusive ProcessesJun 24 1999Semi-inclusive electron scattering provides a powerful tool with which to study the spin and flavor distributions in the proton. Greater kinematic coverage at the proposed Electron-Polarized Ion Collider facility will enable the valence d/u ratio to be ... More
Quark Asymmetries in the ProtonJun 16 1998We review recent experimental and theoretical developments in the study of the sea quark structure of the proton. In the light quark sector, we analyse the recent pp and pD Drell-Yan data from the E866/NuSea experiment at Fermilab, and their implication ... More
Flavor Decomposition of the NucleonSep 21 1999Oct 04 1999I review some recent developments in the study of quark flavor distributions in the nucleon, including (i) valence quark distributions and the quark-hadron duality prediction for the x -> 1 d/u ratio (ii) sea quark asymmetries and electromagnetic form ... More
Models of Interacting Dark EnergyApr 26 2012Any non-gravitational coupling between dark matter and dark energy modifies the cosmological dynamics. Interactions in the dark sector are considered to be relevant to address the coincidence problem. Moreover, in various models the observed accelerated ... More
Planet influence on the shape of the hosting star - ellipsoidal variations of tau BootisDec 18 2008Dec 18 2008This paper presents estimations on the possibility of detection of ellipsoidal variations by means of measuring brightness of the star distorted by a close massive planet using Wilson-Devinney method. The problem was already discussed by Phafl et al. ... More
Polarization Observables in $γN\to K\bar{K}N$Dec 10 2004Dec 10 2004We explore some of the rich structure of the polarization observables recently developed for processes like $\gamma N\to\pi\pi N$ and $\gamma N\to K \bar{K} N$ in the framework of a specific model for the latter process. Emphasis is placed on observables ... More
HQET and Form Factor Effects in $B\to K^{(*)}\ell^+\ell^-$Dec 07 1995We examine the rates for the exclusive decays $B\to K^{(*)}\ell^+\ell^-$. We use the scaling predictions of the heavy quark effective theory to extract the necessary form factors from fits to various combinations of data. These data include the $D\to ... More
On the Heterotic/F-Theory Duality in Eight DimensionsOct 26 1999We review quantitative tests on the duality between the heterotic string on T^2 and F-theory on K3. On the heterotic side, certain threshold corrections to the effective action can be exactly computed at one-loop order, and the issue is to reproduce these ... More
Chiral Rings in Topological (W-)GravityFeb 28 1993Talk given at the 26th Workshop: ``From Superstrings to Supergravity", Erice - Sicily, 5-12 December 1992. We review the superconformal properties of 2d matter coupled to gravity, and extensions thereof. Focusing on topological strings, we recall how ... More
Measuring Chiral Parameters in the Strongly Interacting W system at a Linear ColliderSep 12 1996In the absence of a Higgs particle vector boson scattering amplitudes are generally described by an electroweak chiral Lagrangian below the resonance region. For a Linear Collider with CMS energy $\sqrt{s}=1.6 TeV$ and an integrated luminosity of $200 ... More
THE SOLAR NEUTRINO PROBLEMMar 24 1995The solar neutrino problem has persisted for almost three decades. Recent results from Kamiokande, SAGE, and GALLEX indicate a pattern of neutrino fluxes that is very difficult to reconcile with plausible variations in standard solar models. This situation ... More
Mott-Hubbard transition of cold atoms in optical latticesNov 15 2002May 05 2003We discuss the superfluid to Mott-insulator transition of cold atoms in optical lattices recently observed by Greiner et.al. (Nature 415, 39 (2002)). The fundamental properties of both phases and their experimental signatures are discussed carefully, ... More
Introduction to Landau DampingJan 20 2016The mechanism of Landau damping is observed in various systems from plasma oscillations to accelerators. Despite its widespread use, some confusion has been created, partly because of the different mechanisms producing the damping but also due to the ... More
Spacecone quantization of AdS superparticleMay 27 2010Jun 10 2010We first-quantize the superparticle describing free 10D IIB supergravity on AdS_5xS^5. We choose the worldline coordinate to be a combination of the bulk (spatial) coordinates of anti de Sitter space and the sphere. The Hamiltonian is independent of this ... More
T-duality invariance in random lattice stringsMar 06 1996Preserving the T-duality invariance of the continuum string in its random lattice regularization uniquely determines the random matrix model potential. For D=0 the duality transformation can be performed explicitly on the matrix action, and replaces color ... More
Subcritical SuperstringsMar 24 1995We introduce the Liouville mode into the Green-Schwarz superstring. Like massive supersymmetry without central charges, there is no kappa symmetry. However, the second-class constraints (and corresponding Wess-Zumino term) remain, and can be solved by ... More
Self-Dual N=8 Supergravity as Closed N=2(4) StringsJul 13 1992Jul 14 1992As open N=2 or 4 strings describe self-dual N=4 super Yang-Mills in 2+2 dimensions, the corresponding closed (heterotic) strings describe self-dual ungauged (gauged) N=8 supergravity. These theories are conveniently formulated in a chiral superspace with ... More
Superspace Duality in Low-Energy SuperstringsMay 17 1993May 20 1993We extend spacetime duality to superspace, including fermions in the low-energy limits of superstrings. The tangent space is a curved, extended superspace. The geometry is based on an enlarged coordinate space where the vanishing of the d'Alembertian ... More
Escape of VHE gamma-rays from close massive binary Cen X-3Jul 13 2000We consider propagation of very high energy (VHE) gamma-rays in the radiation field of a massive star in the binary system Cen X-3, which has been reported as a source of gamma-ray photons in the GeV and TeV energies. VHE gamma-rays or electrons, injected ... More
Gamma-ray production in young open clusters: Berk 87, Cyg OB2 and Westerlund 2Apr 26 2007Aug 20 2007Young open clusters are likely sites of cosmic ray acceleration as indicated by recent detections of the TeV gamma-ray sources in the directions of two open clusters (Cyg OB2 and Westerlund 2) and their directional proximity to some unidentified EGRET ... More
Inverse Compton e-p pair cascade model for the gamma-ray production in massive binary LSI +61^o 303Jun 17 2006Jul 13 2006We apply an inverse Compton $e^\pm$ pair cascade model for $\gamma$-ray production in massive binary system LSI +61$^{\rm o}$ 303 assuming that electrons are accelerated already inside the inner part of the jet launched by the compact object. $\gamma$-ray ... More
TeV neutrinos from microquasars in compact massive binariesMay 27 2005We consider a compact binary system in which a Wolf-Rayet star supplies matter onto a stellar mass black hole or a neutron star. This matter forms an accretion disk which ejects a jet as observed in Galactic microquasars. A part of the jet kinetic energy, ... More
withdrawnJul 24 2000Mar 12 2001This paper has been withdrawn by the authors due to new experimental results.
Quantum field theory and the Standard ModelDec 17 2010In this lecture we discuss the basic ingredients for gauge invariant quantum field theories. We give an introduction to the elements of quantum field theory, to the construction of the basic Lagrangian for a general gauge theory, and proceed with the ... More
Standard Model TheoryNov 12 1998Dec 15 1998In this conference report a summary is given on the theoretical work that has contributed to provide accurate theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the vector boson masses, ... More
Critical Binder cumulant of two-dimensional Ising modelsMar 15 2006Apr 05 2006The fourth-order cumulant of the magnetization, the Binder cumulant, is determined at the phase transition of Ising models on square and triangular lattices, using Monte Carlo techniques. Its value at criticality depends sensitively on boundary conditions, ... More
On the Gauge-Independence of the S-MatrixApr 13 2001Apr 19 2001The S-matrix is invariant with respect to the variation of any (global) parameter involved in the gauge fixing conditions, if that variation is accompanied by a certain redefinition of the basis of polarization vectors. Renormalizability of the underlying ... More
An analysis of the vector meson spectrum from lattice QCDSep 12 2003We re-analyse meson sector data from the CP-PACS collaboration's dynamical simulations. Our analysis uses several different approaches, and compares the standard naive linear fit with the Adelaide Anzatz. We find that setting the scale using the J parameter ... More
Neutrino Physics - TheoryJul 10 2003Jul 14 2003We discuss recent developments in neutrino physics and focus, in particular, on neutrino oscillations and matter effects of three light active neutrinos. Moreover, we discuss the difference between Dirac and Majorana neutrinos, neutrinoless $\beta\beta$-decay, ... More
Phenomenology of Neutrino Masses and MixingOct 14 1999We discuss all possible schemes with four massive neutrinos inspired by the existing experimental indications in favour of neutrino mixing, namely the atmospheric, solar and LSND neutrino experiments. We argue that the scheme with a neutrino mass hierarchy ... More
Time-space fabric underlying anomalous diffusionMay 08 2005This study unveils the time-space transforms underlying anomalous diffusion process. Based on this finding, we present the two hypotheses concerning the effect of fractal time-space fabric on physical behaviors and accordingly derive fractional quantum ... More
The muon g-2 experiment at FermilabNov 15 2016A new measurement of the anomalous magnetic moment of the muon, $a_{\mu} \equiv (g-2)/2$, will be performed at the Fermi National Accelerator Laboratory with data taking beginning in 2017. The most recent measurement, performed at Brookhaven National ... More
Hamilton Formalism in Non-Commutative GeometrySep 30 1994We study the Hamilton formalism for Connes-Lott models, i.e., for Yang-Mills theory in non-commutative geometry. The starting point is an associative $*$-algebra $\cA$ which is of the form $\cA=C(I,\cAs)$ where $\cAs$ is itself a associative $*$-algebra. ... More
A representation of retracts of cubesJul 12 2004The purpose of this note is to give the full and self-contained proof of Shchepin's result on a spectral representation of retracts of cubes.
Game-theoretic characterization of the Gurarii spaceApr 23 2016May 06 2017We present a simple and natural infinite game building an increasing chain of finite-dimensional Banach spaces. We show that one of the players has a strategy with the property that, no matter how the other player plays, the completion of the union of ... More
Semi-symmetric Kahler surfacesJul 06 2014May 02 2015The aim of this paper is to describe Kahler surfaces which admit an opposite almost Hermitian structure satisfying the first Gray condition
Relativistic Bound State Equation for Unstable Fermions and the Toponium WidthJan 31 1995The bound state problem for a fermion-antifermion system is considered taking into account a finite decay width of the constituents. We propose an exactly solvable relativistic zero order equation similar to that of Barbieri and Remiddi, but including ... More
Gauge-Independent Bound-State Corrections to the Toponium Decay WidthAug 03 1994Off-shell and relativistic bound-state corrections for the decay $t \to b+W$ are calculated to $O(\a_s^2)$ making full use of the Bethe-Salpeter formalism for weakly bound systems. Thus we are able to take into account all terms to that order in a systematic ... More
Large lepton flavor violating signals in supersymmetric particle decays at future e+ e- collidersJan 30 2002We study lepton flavor violating signals at a future e+ e- linear collider within the general MSSM, allowing for the most general flavor structure. We demonstrate that there is a large region in parameter space with large signals, while being consistent ... More
Nucleon Structure Functions from Relativistic Constituent QuarksJun 30 1994We investigate deep inelastic lepton scattering from the nucleon within a constituent quark picture, in which the internal structure of constituent quarks is modeled by meson and diquark dressing. In a covariant framework this structure leads to a breakdown ... More
Pac-learning Recursive Logic Programs: Negative ResultsMay 01 1995In a companion paper it was shown that the class of constant-depth determinate k-ary recursive clauses is efficiently learnable. In this paper we present negative results showing that any natural generalization of this class is hard to learn in Valiant's ... More
On the variability of the GeV and multi-TeV gamma-ray emission from the Crab NebulaNov 18 2010Feb 15 2011Recently the AGILE $\gamma$-ray telescope has reported the enhanced $\gamma$-ray emission above 100 MeV from the direction of the Crab Nebula during a period of a few days. This intriguing observation has been confirmed by the Fermi-LAT telescope. This ... More
Influence of Spin Wave Excitations on the Ferromagnetic Phase Diagram in the Hubbard-ModelSep 20 2002The subject of the present paper is the theoretical description of collective electronic excitations, i.e. spin waves, in the Hubbard-model. Starting with the widely used Random-Phase-Approximation, which combines Hartree-Fock theory with the summation ... More
Cosmic BaldnessSep 16 2011We elucidate the mechanism where by gravitational fluctuations are frozen in during a period of inflation but nevertheless within the past horizon of any geodesic observer the spacetime settles down exponentially fast to the de-Sitter metric.
RX J1548.9+0851, a fossil cluster?Feb 20 2012Fossil galaxy groups are spatially extended X-ray sources with X-ray luminosities above L_X,bol > 10^42 h_50^-2 ergs s^-1 and a central elliptical galaxy dominating the optical, the second-brightest galaxy being at least 2 magnitudes fainter in the R ... More
Deuteron Structure Functions in the Context of Few-Body PhysicsAug 29 1997Few-body systems offer a unique challenge to those interested in deep inelastic scattering. Using the deuteron as the simplest and most easily solvable nuclear system we review the main physics issues in the valence and sea quark regimes. For the former ... More
Pion Content of the Nucleon in Polarized Semi-Inclusive D.I.sOct 10 1994An explicit pionic component of the nucleon may be identified by measuring polarized $\Delta^{++}$ fragments produced in deep-inelastic scattering off polarized protons. The pion-exchange model predicts highly correlated polarizations of the $\Delta^{++}$ ... More
Strong Coupling Descriptions of High Temperature Superconductors: Electronic Attraction from a Repulsive PotentialJul 13 1994We consider the effect of the nearest neighbour copper-oxygen repulsion, V, when coupled to the charge transfer resonances Cu2+ to Cu3+ and Cu2+ to Cu+ in the high temperature cuprate superconductors. This is done by deriving effective low energy Hamiltonians ... More
Connecting structure functions on the lattice with phenomenologyJan 30 2002We examine the extraction of moments of parton distributions from lattice data, focusing in particular on the chiral extrapolation as a function of the quark mass. Inclusion of the correct chiral behavior of the spin-averaged isovector distribution resolves ... More
Extraction of parton distributions from lattice QCDOct 02 2003We review the calculation of moments of both the polarized and unpolarized parton distribution functions of the nucleon in lattice QCD, and in particular their extrapolation to the physical region. We also discuss the reconstruction of the x dependence ... More
Moments of Isovector Quark Distributions from Lattice QCDJun 03 2002Jul 19 2002We present a complete analysis of the chiral extrapolation of lattice moments of all twist-2 isovector quark distributions, including corrections from N pi and Delta pi loops. Even though the Delta resonance formally gives rise to higher order non-analytic ... More
Parton distributions from lattice QCDAug 02 2001Sep 27 2001We extract the x dependence of the nonsinglet u-d distribution function in the nucleon from the lowest few moments calculated on the lattice, using an extrapolation formula which ensures the correct behavior in the chiral and heavy quark limits. We discuss ... More
Exact elegant Laguerre-Gaussian vector wave packetsNov 20 2012Feb 22 2013An exact closed-form representation is derived of a vector elegant Laguerre-Gaussian wave packet. Its space-time representation consists of three mutually orthogonal field components - of a common azimuthal index and different radial indices - uniquely ... More
Multipartite bound entangled states that violate Bell's inequalityJul 09 2001We study the relation between distillability of multipartite states and violation of Bell's inequality. We prove that there exist multipartite bound entangled states (i.e. non-separable, non-distillable states) that violate a multipartite Bell inequality. ... More
Neutrino mass matrices leaving no traceAug 11 2003We point attention to the fact that in SO(10) models with non-canonical (type II) see-saw mechanism and exact b-tau unification the trace of the neutrino mass matrix is very small, in fact practically zero. This has the advantage of being a basis independent ... More
Leptogenesis, neutrinoless double beta decay and terrestrial CP violationOct 18 2001Leptogenesis in left-right symmetric theories is studied. The usual see-saw mechanism is modified by the presence of a left-handed Higgs triplet. A simple connection between the properties of the light left-handed and heavy right-handed neutrinos is found. ... More
A Parametrization for the Neutrino Mixing MatrixSep 22 2003Dec 06 2003We propose a flexible and model independent parametrization of the neutrino mixing matrix, which takes advantage of the fact that there are up to three small quantities in neutrino mixing phenomenology: (i) the deviation from maximal mixing of solar neutrinos, ... More
The ELENA project at CERNJan 23 2015CERN has a longstanding tradition of pursuing fundamental physics on extreme low and high energy scales. The present physics knowledge is successfully described by the Standard Model and the General Relativity. In the anti-matter regime many predictions ... More
Convolution/deconvolution of generalized Gaussian kernels with applications to proton/photon physics and electron capture of charged particlesAug 30 2012Sep 01 2012Scatter processes of photons lead to blurring of images produced by CT (computed tomography) or CBCT (cone beam computed tomography) in the KV domain or portal imaging in the MV domain (KV: kilovolt age, MV: megavoltage). Multiple scatter is described ... More
Quantum mechanical aspects of friction and electric resistance in microscopic problems with applications to radiation physicsJan 30 2015Friction incorporates the close connection between classical mechanics in irreversible thermodynamics. The translation to a quantum mechanical foundation is not trivial and requires a generalization of the Lagrange function. A change to electromagnetic ... More
Radiobiological investigations at tumor cell lines by exploiting chrono-biological aspects of chronological dose distributionsNov 29 2011Dec 10 2011Using 31P-NMR spectroscopy the chronological behavior of the ATP-metabolism of the tumor spheroids C3H-MA, 9L-Gliome and the mono-layer L1210 has been analyzed via decrease of the {\beta}-peak. All three cell lines show characteristic periods, and a homeostatic ... More
Solution of coupled vertex and propagator Dyson-Schwinger equations in the scalar Munczek-Nemirovsky modelJan 03 2003Apr 23 2003In a scalar $\phi^2\chi$ model, we exactly solve the vertex and $\phi$ propagator Dyson-Schwinger equations under the assumption of a spatially constant (Munczek-Nemirovsky) propagator for the $\chi$ field. Various truncation schemes are also considered. ... More
Higher twists in the pion structure functionMar 17 2003We calculate the QCD moments of the pion structure function using Drell-Yan data on the quark distributions in the pion and a phenomenological model for the resonance region. The extracted higher twist corrections are found to be larger than those for ... More
Derivation of a Fluctuation Theorem from the probabilistic definition of entropySep 08 2005It will be shown, how the Boltzmannian ideas on statistical physics can be naturally applied to nonequilibrium thermodynamics. A similar approach for treating nonequilibrium phenomena has been successfully used by Einstein and Smoluchowski treating fluctuations. ... More
An X-ray source population study of the Andromeda galaxy M 31Nov 01 2005XMM-Newton EPIC observations reveal the population of X-ray sources of the bright Local Group spiral galaxy M 31, a low-star-formation-rate galaxy like the Milky Way, down to a 0.2-4.5 keV luminosity of 4.4E34 erg/s. With the help of X-ray hardness ratios ... More