June 1996 arXiv papers — page 8

ZEUS Collaboration, M. Derrick et al

In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independe

Tae-Suk Kim, L. N. Oliveira, D. L. Cox

We study a new exchange interaction in which the conduction electrons with pseudo spin $S_c=3/2$ interact with the impurity spin $S_I=1/2$. Due to the overscreening of the impurity spin by higher conduction electron spin, a new non-trivial intermediate coupling strength fixed point is realized. Using the numerical renormalization group (NRG), we show that th

H. C. Rosu, J. Socorro

We apply the strictly isospectral technique of standard supersymmetric quantum mechanics to the Q=0 factor ordered Wheeler-DeWitt equation for the Friedmann-Robertson-Walker (FRW) minisuperspace model. The resulting strictly isospectral one-parameter families of both FRW cosmological potentials and "wavefunctions of the universe" are exhibited with r

Andrei Losev, Gregory Moore, Nikita Nekrasov, Samson Shatashvili

We investigate higher-dimensional analogues of the $bc$ systems of 2D RCFT. When coupled to gauge fields and Beltrami differentials defining integrable holomorphic structures the $bc$ partition functions can be explicitly evaluated using anomalies and holomorphy. The resulting induced actions generalize the chiral algebras of 2D RCFT to $2n$ dimensions. More

Hagen Kleinert, Adriaan Schakel

The superconductive phase transition in the Ginzburg-Landau theory (or Coulomb-Higgs phase transition of scalar QED in 3D) is discussed in a dual formulation which focuses on the magnetic rather than the electric excitations of the system. Renormalization group analysis of the dual formulation reveals the transition to be of second order and of a new univers

M. Dakna, L. Knoll, D. -G. Welsch

Coarse-grained phase distributions are introduced that approximate to the Susskind--Glogower cosine and sine phase distributions. The integral relations between the phase distributions and the phase-parametrized field-strength distributions observable in balanced homodyning are derived and the integral kernels are analyzed. It is shown that the phase distrib

V. Koch, C. Song

The production of dileptons is studied within a hadronic transport model. We investigate the sensitivity of the dilepton spectra to the initial configuration of the hadronic phase in a ultrarelativistic heavy ion collision. Possible in medium correction due to the modifications of pions and the pion form factor in a hadronic gas are discussed.

C. Spieles, M. Bleicher, L. Gerland, H. Stoecker

The dynamics of a hadronizing quark matter drop is investigated with a hybrid-like model, which takes into account equilibrium as well as non-equilibrium features of the process. We study the the particle rates from the hadronizing plasma, which have to be put in relation to the whole time evolution of the system. The impact of finite-size effects on the dis

Hitoshi Nishino, S. J. Gates,

We give generalizations of extended Poincaré supergravity with {\it arbitrarily many} supersymmetries in the absence of central charges in three-dimensions by gauging its intrinsic global $~SO(N)$~ symmetry. We call these \alephnull (Aleph-Null) supergravity theories. We further couple a non-Abelian supersymmetric Chern-Simons theory and an Abelian topologic

L. Faddeev, A. Yu. Volkov

The shift operator for a quantum lattice current algebra associated with sl(2) is produced in the form of product of local factors. This gives a natural deformation of the Sugawara construction for discrete space-time.

Sheldon Katz, Cumrun Vafa

We provide a local geometric description of how charged matter arises in type IIA, M-theory, or F-theory compactifications on Calabi-Yau manifolds. The basic idea is to deform a higher singularity into a lower one through Cartan deformations which vary over space. The results agree with expectations based on string dualities.

M. Mekhfi

After summarising the physical approach leading to twisted homotopy and after developing the cohomological approach further with respect to our previous work we propose a third alternative approach to twisted homotopy based on group theoretic considerations. In this approach the fundamental group $Π(m) $ isomorphic to Z which describes homotopic loops on the

Mauri Miettinen

We consider supersymmetrization of Hamiltonian dynamics via antibrackets for systems whose Hamiltonian generates an isometry of the phase space. We find that the models are closely related to the supersymmetric non-linear $σ$-model. We interpret the corres\-ponding path integrals in terms of super loop space equivariant cohomology. It turns out that they can

Heinz König

In this talk I present a detailed SUSY QCD calculation of the decay rate of the lightest Higgs boson $H^0_2$\ into two gluons, where all quarks and scalar quarks are taken within the relevant loop diagrams. I include the mixing of all the three generations of the scalar partners of the left and right handed quarks and show that their contribution is comparab

D. B. Lichtenberg

It is argued from the systematics of spin-depen\-dent forces between quarks that two proposed baryon states, named $Σ_c(2380)$ and $Σ_b(5760)$, do not exist.

M. M. Boyce, M. A. Doncheski, H. König

We investigate the possibility of studying E$_6$ phenomenology at high energy hadron colliders. The production of heavy leptons pairs {\it via} a gluon-gluon fusion mechanism is discussed. An enhancement in the parton level cross-section is expected due to the heavy (s)fermion loops which couple to the gluons.

B. Holdom

There is current interest in a possible new massive gauge boson $X$ which mixes slightly with the $Z$ boson and accounts for certain anomalies in the LEP data. We show why constraints on models in which the $X$ boson does not couple to the first two families suggest dynamical electroweak symmetry breaking. The associated TeV mass fermions make up a fourth fa

Jamal Jalilian-Marian, Alex Kovner, Larry McLerran, Heribert Weigert

We compute the distribution functions for gluons at very small x and not too large values of transverse momenta. We extend the McLerran-Venugopalan model by using renormalization group methods to integrate out effects due to those gluons which generate an effective classical charge density for Weizsäcker-Williams fields. We argue that this model can be exten

S. V. Chekanov, W. Kittel, V. I. Kuvshinov

Experimental aspects of the use of bunching parameters are discussed. Special attention is paid to the behavior expected for the case of purely statistical fluctuations. We studied bin-averaged bunching parameters and propose a generalization of bunching parameters, making use of the interparticle distance-measure technique. The proposed method opens up the

Felix M. Lev

Restrictions imposed on the (electromagnetic or weak) current operator by its commutation relations with the representation operators of the Poincare group are considered in detail. We argue that the present theory of deep inelastic scattering based on perturbative QCD does not take into account the dependence of the current operator on the nonperturbative p

N. Armesto, M. A. Braun, E. G. Ferreiro, C. Pajares

It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. The spectrum of different particles is compared with the high energy data on p--A collisions obtaining a reasonable agreement. Results for A--B collisions at $\sqrt{s}=19.4$ AGeV and $\sqrt{s}

Erwin Mirkes, Dieter Zeppenfeld

Next-to-leading order corrections to jet cross sections in deep inelastic scattering at HERA are studied. The predicted jet rates allow for a precise determination of $α_s(μ_R)$ at HERA over a wide range of $μ_R$. We argue, that the ``natural'' renormalization and factorization scale is set by the average $k_T^B$ of the jets in the Breit frame and su

Masayasu Harada

In this talk I summarize a recently proposed mechanism to understand pi pi scattering to 1 GeV. The model is motivated by the 1/Nc expansion to QCD, and includes a current algebra contact term and resonant pole exchanges. Chiral symmetry plays an important role in restricting the form of the interactions. The existence of a broad low energy scalar (sigma) is

Lawrence P. Horwitz

A consistent classical and quantum relativistic mechanics can be constructed if Einstein's covariant time is considered as a dynamical variable. The evolution of a system is then parametrized by a universal invariant identified with Newton's time. This theory, originating in the work of Stueckelberg in 1941, contains many questions of interpretation,

Marcelo Salgado, Daniel Sudarsky, Hernando Quevedo

There are many indications that ordinary matter represents only a tiny fraction of the matter content of the Universe, with the remainder assumed to consist of some different type of matter, which, for various reasons must be nonluminous (dark matter). Among these indications are the inflationary scenarios which predicts that the average energy density of th

Marcelo Salgado, Daniel Sudarsky, Hernando Quevedo

We consider the model involving the oscillation of the effective gravitational constant that has been put forward in an attempt to reconcile the observed periodicity in the galaxy number distribution with the standard cosmological models. This model involves a highly nonlinear dynamics which we analyze numerically. We carry out a detailed study of the bound

Pedro F. Gonzalez-Diaz

By allowing the light cones to tip over on hypersurfaces according to the conservation laws of an one-kink in static, Schwarzschild and five-dimensional black hole metrics, we show that in the quantum regime there also exist instantons whose finite imaginary action gives the probability of accurrence of the kink metric corresponding to single chargeless, non

L. V. Verozub

We argue that space-time geometry is not absolute with respect to the frame of reference being used. The space-time metric differential form $ds$ in noninertial frames of reference (NIFR) is caused by the properties of the used frames in accordance with the Berkley - Leibnitz - Mach - Poincaré ideas about relativity of space and time . It is shown that the S

Yu. A. Baurov, A. A. Efimov, A. A. Shpitalnaya

The processing of the galactic coordinates of 3543 solar flares with a magnitude of 2 or more has shown that the distribution of these fast-going processes on the surface of the "nonrotating" Sun is irregular and non-random what testifies that in the near-Sun space an anisotropy takes place which practically coincides with that predicted and obtained

M. R. de Garcia Maia, J. A. S. Lima

The problem of cosmological graviton creation for homogeneous and isotropic universes with elliptical ($\vae =+1$) and hyperbolical ($\vae =-1$) geometries is addressed. The gravitational wave equation is established for a self-gravitating fluid satisfying the barotropic equation of state $p=(γ-1)ρ$, which is the source of the Einstein's equations plus a

D. V. Ahluwalia, C. Burgard

We present some thoughts on how to interpret the gravitionally induced neutrino oscillation phases presented by us in our 1996 Gravity Research Foundation Essay.

Francis Burstall, Martin Guest

Uhlenbeck introduced an invariant, the (minimal) uniton number, of harmonic 2-spheres in a Lie group G and proved that when G=SU(n) the uniton number cannot exceed n-1. In this paper, using new methods inspired by Morse Theory, we explain this result and extend it to an arbitrary compact group G. The same methods also yield Weierstrass formulae for these har

S. Giorgini, J. Boronat, J. Casulleras

We present a diffusion Monte Carlo study of a single vortex in two-dimensional superfluid liquid $^4$He within the fixed node approximation. We use both the Feynman phase and an improved phase which includes backflow correlations to model the nodal surface of the vortex wavefunction. Results for the particle density, core radius and excitation energies are p

F. G. Pikus, A. M. Tikofsky

The energetic properties of a paired quantum Hall state at Landau level filling $ν=2$ are investigated using variational Monte Carlo techniques. Pairing is found to be energetically favorable in small magnetic fields because it introduces correlations between up and down spins that are absent in the traditional $ν=2$ state. We find that pairing survives extr

Jeong-Man Park, T. C. Lubensky, F. C. MacKintosh

We consider in mean-field theory the continuous development below a second-order phase transition of $n$-atic tangent plane order on a deformable surface of genus zero with order parameter $ψ= \langle e^{i n θ} \rangle$. Tangent plane order expels Gaussian curvature. In addition, the total vorticity of orientational order on a surface of genus zero is two. T

Holger Schanz, Ivan Barvik, Bernd Esser

Transfer and decay dynamics of an exciton coupled to a polarization vibration in a dimer is investigated in a mixed quantum-classical picture with the exciton decay incorporated by a sink site. Using a separation of time scales, it is possible to explain analytically the most important characteristics of the model. If the vibronic subsystem is fast, these ar

Igor Zutic, Oriol T. Valls

We consider the nonlinear transverse magnetic moment that arises in the Meissner state of superconductors with strongly anisotropic order parameter. We compute this magnetic moment as a function of applied field and geometry, assuming d-wave pairing, for realistic samples, finite in all three dimensions, of high temperature superconducting materials. Return

Liang-Jian Zou, X. G. Gong, Zheng-Gang Zhu

In this letter, the possible dynamic scaling properties of protein molecules in folding are investigated theoretically by assuming that the protein molecules are percolated networks. It is shown that the fractal character and the fractal dimensionality may exist only for short sequences in large protein molecules and small protein molecules with homogeneous

Juerg Froehlich, Roland Goetschmann

We consider systems of non-relativistic, interacting electrons at finite density and zero temperature in d = 2, 3, ... dimensions. Our main concern is to characterize those systems that, under the renormalization flow, are driven away from the Landau Fermi liquid (LFL) renormalization group fixed point. We are especially interested in understanding under wha

D. Sherrington, A. C. C. Coolen, S. N. Laughton

It is shown how the macroscopic non-equilibrium dynamics of a class of systems whose microscopic stochastic dynamics involves disordered and frustrated but range-free interactions can be well described by closed deterministic flow equations; this requires an appropriate choice of order parameters/function and ansatze.

Mario Nicodemi, Antonio Coniglio, Hans J. Herrmann

We introduce a lattice model, in which frustration plays a crucial role, to describe relaxation properties of granular media. We show Monte Carlo results for compaction in the presence of vibrations and gravity, which compare well with experimental data.

Daniel Olguin, Rafael Baquero

We have calculated the electronic band structure of the (100) surface of the III--V zinc blende semiconductor compounds, using the standard tight binding method and the surface Green's function matching method. We have found that the creation of the surface gives place to new states in the electronic structure: surface resonances and two dimensional bulk

Richard Sproat, Michael Riley

We report on a method for compiling decision trees into weighted finite-state transducers. The key assumptions are that the tree predictions specify how to rewrite symbols from an input string, and the decision at each tree node is stateable in terms of regular expressions on the input string. Each leaf node can then be treated as a separate rule where the l

Gabriele Scheler

In this paper, we use a feature model of the semantics of plural determiners to present an approach to grammar checking for definiteness. Using neural network techniques, a semantics -- morphological category mapping was learned. We then applied a textual encoding technique to the 125 occurences of the relevant category in a 10 000 word narrative text and le

Francis J. Alexander, Gregory L. Eyink

We demonstrate the utility of a Rayleigh-Ritz scheme recently proposed to compute the nonequilibrium effective potential nonperturbatively in a strong noise regime far from equilibrium. A simple Kramers model of an ionic conductor is used to illustrate the efficiency of the method.

H. van Beijeren, J. R. Dorfman, E. G. D. Cohen, H. A. Posch

Positive and negative Lyapunov exponents for a dilute, random, two-dimensional Lorentz gas in an applied field, $\vec{E}$, in a steady state at constant energy are computed to order $E^{2}$. The results are: $λ_{\pm}=λ_{\pm}^{0}-a_{\pm}(qE/mv)^{2}t_{0}$ where $λ_{\pm}^{0}$ are the exponents for the field-free Lorentz gas, $a_{+}=11/48, a_{-}=7/48$, $t_{0}$ i

Arul Lakshminarayan

Using quantum maps we study the accuracy of semiclassical trace formulas. The role of chaos in improving the semiclassical accuracy, in some systems, is demonstrated quantitatively. However, our study of the standard map cautions that this may not be most general. While studying a sawtooth map we demonstrate the rather remarkable fact that at the level of th

István Szapudi, Avery Meiksin, Robert C. Nichol

Counts in cells are used to analyse the higher order properties of the statistics of the EDSGC survey. The probability distribution is obtained from an equal area projection source catalog with infinite oversampling over the range $0.015^\circ-2^\circ$. The factorial moments of the resulting distribution and the $s_N$'s characterizing the non-Gaussian na

Byung-Il Jun, Michael L. Norman

We study the radio emission from young supernova remnants by means of 3D numerical MHD simulations of the Rayleigh-Taylor instability in the shell of the remnant. The computation is carried out in spherical polar coordinates ($r, θ, ϕ$) by using a moving grid technique which allows us to finely resolve the shell. Three-dimensional result shows more turbulent

V. S. Shergin, A. Yu. Kniazev, V. A. Lipovetsky

In this paper the definitions and the properties of a newle dedicated set of high-frequency filters based on smoothing-and-clipping are briefly described. New applications for reduction of wide--field 2048x2048 CCD spectral and direct images of a new deep survey KISS (KPNO International Spectral Survey) are also presented. The developed software is available

Steven D. Kawaler

The MACHO collaboration lensing event statistics suggest that a significant fraction of the dark galactic halo can be comprised of baryonic matter in the form of white dwarf stars with masses between 0.1 and 1.0 \Msun . Such a halo white dwarf population, in order to have escaped detection by those who observe the white dwarf luminosity function of the disk,

Byung-Il Jun, T. W. Jones, Michael L. Norman

We discover a new dynamical mechanism that significantly enhances the growth of Rayleigh-Taylor fingers developed near the contact interface between the supernova ejecta and swept-up ambient gas in young supernova remnants if the supernova remnant expands into a clumpy (cloudy) circumstellar medium. Our numerical simulation demonstrates that large Rayleigh-T

J. Greiner, N. Bade, K. Hurley, R. M. Kippen

The strong GRB of March 1, 1994 was imaged by COMPTEL and found to have an identical location within the errors as a burst which occurred on July 4, 1993. This location coincidence had prompted speculations on a possible single source origin for both bursts. We have performed a ROSAT PSPC mosaic observation within four weeks of GRB 940301. The results of the

Gonzalo Parente, Enrique Zas

We study the potential of the Pierre Auger detector for horizontal air showers initiated by ultra high energy neutrino. Assuming some simple trigger requirements we obtain measurable event rates for neutrino fluxes from AGN, from topological defects and from the interactions of cosmic rays with the microwave background.

Ya. V. Pavlenko, A. Magazzu

Detailed simultaneous radiative transfer-statistical equilibrium calculations have been performed for lithium in atmospheres of solar metallicity G-M dwarfs and subgiants. Model atmospheres of stars with $3500 \le \Tf \le 6000$ K, $3.0 \le \lgg \le 4.5$ have been considered. The behaviour of level populations, source functions and curves of growth for the li

R. H. Sanders

A sample of 22 spiral galaxy rotation curves, measured in the 21 cm line of neutral hydrogen, is considered in the context of Milgrom's modified dynamics (MOND). Combined with the previous highly selected sample of Begeman et al. (1990), this comprises the current total sample of galaxies with published (or available) extended rotation curves and photome

J. Meaburn, P. Boumis, J. R. Walsh, W. Steffen

Spatially resolved H$α$ and [N{\sc ii}] line profiles have been obtained over striking features in the outer regions of the Eta Carinae nebula. The highly irregular outer `shell' of low ionization, [N{\sc ii}] bright, knots has been shown to exhibit radial velocities between -1200 and +300 km/s with respect to the systemic radial velocity, over its perim

Romuald A. Janik, Maciej A. Nowak, Gábor Papp, Ismail Zahed

We use a chiral random matrix model with 2N_f flavors to mock up the QCD Dirac spectrum at finite chemical potential. We show that the 1/N approximation breaks down in the quenched state with spontaneously broken chiral symmetry. The breakdown condition is set by the divergence of a two-point function, that is shown to follow the general lore of macroscopic

A. Edery, M. B. Paranjape

Stationary solutions to the full non-linear topologically massive gravity (TMG) are obtained for localized sources of mass $m$ and spin $σ$. Our results show that the topological term induces spin and that the total spin J (which is the spin observed by an asymptotic observer) ranges from 0 to $σ+ \frac{m}μ(\frac{4π+m}{4π+2m})$ depending on the structure of

T. Gisiger, M. B. Paranjape

We study the properties of soliton solutions in an analog of the Skyrme model in 2+1 dimensions whose Lagrangian contains the Skyrme term and the mass term, but no usual kinetic term. The model admits a symmetry under area preserving diffeomorphisms. We solve the dynamical equations of motion analytically for the case of spinning isolated baryon type soliton

Jerrold Franklin

The mixing angle between the Xi_c and Xi_c' baryons is shown to be small, with a negligible shift in the Xi_c masses.

A. D. Popov, M. Bordemann, H. Roemer

We describe an infinite-dimensional algebra of hidden symmetries for the self-dual gravity equations. Besides the known diffeomorphism-type symmetries (affine extension of w(infinity) algebra), this algebra contains new hidden symmetries, which are an affine extension of the Lorentz rotations. The full symmetry algebra has both Kac-Moody and Virasoro-like ge

Jens V. Villumsen, Wolfram Freudling, Luiz N. da Costa

We compute the two-point angular correlation function $w(θ)$ for a sample of $\sim$ 1700 galaxies to a magnitude-limit equivalent to $R \sim 29.5$ using a catalog derived from the Hubble Deep Field images. A non zero value of $w(θ)$ is measured down to $R=29.0$. The amplitude of $w(θ)$ at the bright magnitude limit ($R \sim 26$) is consistent with previous g

Gilles Chabrier, Laurent Segretain, Dominique Méra

We examine the recent results of the MACHO collaboration towards the Large Magellanic Cloud (Alcock et al. 1996) in terms of a halo brown dwarf or white dwarf population. The possibility for most of the microlensing events to be due to brown dwarfs is totally excluded by large-scale kinematic properties. The white dwarf scenario is examined in details in the

Maximilian F. Hasler

We present an N=2 multiplet including a three-index antisymmetric tensor gauge potential, and describe it as a solution to the Bianchi identities for the associated fieldstrength superform, subject to some covariant constraints, in extended central charge superspace. We find that this solution is given in terms of an 8+8 tensor multiplet subject to an additi

I. Jack, D. R. T. Jones, C. G. North

We calculate the three loop gauge $β$-function for an abelian $N=1$ supersymmetric gauge theory, using DRED. We construct a coupling constant redefinition that relates the result to the corresponding term in the NSVZ $β$-function, and by generalising this redefinition to the non-abelian case we derive the DRED three loop gauge $β$-function for the non-abelia

Christoph Gutsfeld, Jens Kuester, Gernot Muenster

For the universality class of three-dimensional Ising systems the ratio of the high- and low-temperature amplitudes for the correlation length and for the susceptibility are universal quantities. They can be calculated by renormalized perturbation theory for scalar $ϕ^4$ theory in fixed dimensions $D=3$ in the symmetric phase and in the phase of broken symme

Matthias Troyer, M. E. Zhitomirsky, Kazuo Ueda

Using a combination of analytical techniques and Quantum Monte Carlo simulations we investigate the coupled spin ladder system LaCuO2.5. At a critical ratio of the interladder to intraladder coupling (J'/J)_c \approx 0.11 we find a quantum phase transition between a Neel ordered and a disordered state. At criticality the uniform susceptibility behaves as

Haye Hinrichsen, Vladimir Rittenberg, Horatiu Simon

We investigate with the help of analytical and numerical methods the reaction A+A->A on a one-dimensional lattice opened at one end and with an input of particles at the other end. We show that if the diffusion rates to the left and to the right are equal, for large x, the particle concentration c(x) behaves like As/x (x measures the distance to the input en

Hang Li

We address the problem of structural disambiguation in syntactic parsing. In psycholinguistics, a number of principles of disambiguation have been proposed, notably the Lexical Preference Rule (LPR), the Right Association Principle (RAP), and the Attach Low and Parallel Principle (ALPP) (an extension of RAP). We argue that in order to improve disambiguation

K. Jedamzik, V. Katalinic, A. Olinto

We examine the evolution of magnetic fields in an expanding fluid composed of matter and radiation with particular interest in the evolution of cosmic magnetic fields. We derive the propagation velocities and damping rates for relativistic and non-relativistic fast and slow magnetosonic, and Alfvén waves in the presence of viscous and heat conducting process

Jeremy Schiff

A simple version of the Segal-Wilson map from the SL(2,C) loop group to a class of solutions of the KdV hierarchy is given, clarifying certain aspects of this map. It is explained how the known symmetries, including Backlund transformations, of KdV arise from simple, field independent, actions on the loop group. A variety of issues in understanding the algeb

Ary W. Espinosa--Müller, Adelio R. Matamala Vásquez

The algebraic approach to operator perturbation method has been applied to two quantum--mechanical systems ``The Stark Effect in the Harmonic Oscillator'' and ``The Generalized Zeeman Effect''. To that end, two realizations of the superoperators involved in the formalism have been carried out. The first of them has been based on the Heisenber

M. A. Nielsen

Two new expressions for the entanglement fidelity recently introduced by Schumacher (LANL e-print quant-ph/9604023, to appear in Phys. Rev. A) are derived. These expressions show that it is the entanglement fidelity which must be maximized when performing error correction on qubits for quantum computers, not the fidelity, which is the most-often used general

M. J. Rodriguez-Plaza

We reproduce the hierarchy of link invariants associated to the series of $N$-state vertex models with a method different from the original construction due to Akutsu, Deguchi and Wadati. The alternative method substitutes the `crossing symmetry' property exhibited by the Boltzmann weights of the vertex models by a similar property which, for the purpose

A. Dimakis, C. Tzanakis

In the context of a noncommutative differential calculus on the algebra of real valued functions of an $n$-dimensional manifold $M$, a commutative and associative product of 1-forms is naturally defined. Ordinary differential calculus corresponds to this product being trivially zero. We consider the minimal generalization in which the algebra of 1-forms with

Frank X. Lee, Derek B. Leinweber, Xuemin Jin

New QCD sum rules for the nucleon axial-vector current coupling constants are derived. One set is derived from a generalized correlator of spin-1/2 interpolating fields, and the other with a mixed correlator of spin-1/2 and spin-3/2 fields. Using a recently-developed Monte-Carlo based uncertainty analysis and techniques for determining the optimal interpolat

Xuemin Jin, B. K. Jennings

The quark-meson coupling (QMC) model for nuclear matter, which describes nuclear matter as non-overlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons is modified by the introduction of a density dependent bag constant. It is found that when the bag constant is significantly reduced in nuclear medium with respect to its free sp

T. Mart, C. Bennhold, L. Alfieri

Kaon photo- and electroproduction in all six isospin channels are investigated by means of an isobaric model. It is found that existing models can only partially describe the current experimental data. Moreover, the extracted coupling constants are mostly inconsistent with the prediction of SU(3) symmetry or the information from hadronic reactions. In order

H. Nakada, T. Sebe, K. Muto

We discuss two conditions needed for correct computation of $2νββ$ nuclear matrix-elements within the realistic shell-model framework. An algorithm in which intermediate states are treated based on Whitehead's moment method is inspected, by taking examples of the double GT$^+$ transitions $\mbox{$^{36}$Ar}\rightarrow\mbox{$^{36}$S}$, $\mbox{$^{54}$Fe}\ri

Sergei Lysenko

The functional equation f(p(z))=g(q(z)) is studied, where p,q are polynomials and f,g are trancendental meromorphic functions in C. We find all the pairs p,q for which there exist nonconstant f,g satisfying our equation and there exist no rational f,g with this property. In fact, a more general problem is solved. In addition to algebraic methods, some result

V. Milani, A. Shafei Deh Abad

A general definition of the curves and geodesics associated with a given connection on a quantized manifold is given. In the particular case of the functional quantization we define geodesics in the same way as in the classical case and we will show that the two definitions are compatible. As an example we examine our results for the quantum plane.

F. A. Dilkes, L. C. Martin, D. G. C. McKeon, T. N. Sherry

We compute the contribution to the modulus of the one-loop effective action in pure non-Abelian Chern-Simons theory in an arbitrary covariant gauge. We find that the results are dependent on both the gauge parameter ($α$) and the metric required in the gauge fixing. A contribution arises that has not been previously encountered; it is of the form $(α/ \sqrt{

Laurent Baulieu, Michael B. Green, Eliezer Rabinovici

The heterotic and type II superstring actions are identified in different anomaly-free decompositions of a single topological sigma-model action depending on bosonic and fermionic coordinates, $X^μ$ and $\r^A$ respectively, and of their topological ghosts. This model results from gauge-fixing the topological gauge symmetry $δX^μ= ε^μ(z,\bar z)$ ($μ=1,2,\dots

Luca Lusanna, Paolo Valtancoli

We search a canonical basis of Dirac's observables for the classical non-Abelian Higgs model with fermions in the case of a trivial SU(2) principal bundle with a complex doublet of Higgs fields and with the fermions in a given representation of SU(2). Since each one of the three Gauss law first class constraints can be solved either in the corresponding

Luca Lusanna, Paolo Valtancoli

We search a canonical basis of Dirac's observables for the classical Abelian Higgs model with fermions in the case of a trivial U(1) principal bundle. The study of the Gauss law first class constraint shows that the model has two disjoint sectors of solutions associated with two physically different phases. In the electromagnetic phase, the electromagnet

Anna Okopińska

The generating functionals for the local composite operators, $Φ^2(x)$ and $Φ^4(x)$, are used to study excitations in the scalar quantum field theory with $λΦ^4$ interaction. The effective action for the composite operators is obtained as a series in the Planck constant $\hbar$, and the two- and four-particle propagators are derived. The numerical results ar

F. G. Scholtz, S. V. Shabanov

We develop a new operator quantization scheme for gauge theories where no gauge fixing for gauge fields is needed. The scheme allows one to avoid the Gribov problem and construct a manifestly Lorentz invariant path integral that can be used in the non-perturbative domain. We discuss briefly an application of the method to Abelian projections of QCD.

Ben Craps, Frederik Roose, Walter Troost, Antoine Van Proeyen

The scalars in vector multiplets of N=2 supersymmetric theories in 4 dimensions exhibit `special Kaehler geometry', related to duality symmetries, due to their coupling to the vectors. In the literature there is some confusion on the definition of special geometry, which we want to clear up, for rigid as well as for local N=2.

R. Guida, N. Magnoli

We apply here a recently developed approach to compute the short distance corrections to scaling for the correlators of all primary operators of the critical two dimensional Ising model in a magnetic field. The essence of the method is the fact that if one deals with O.P.E. Wilson coefficients instead of correlators, all order I.R. safe formulas can be obtai

Isard Dunietz, Joseph Incandela, Frederick D. Snider, Kyuzo Tesima

Discrepancies between Standard Model predictions and experimental measurements of the fractions R_c and R_b of hadronic Z decays to charm and bottom are investigated. We show that there exists a discrepancy in two complementary determinations of B(Bbar --> D X). Reducing the branching ratio B(D0 --> K- Pi+) by about 15% from currently accepted values to 3.50

Howard Baer, Ray Munroe, Xerxes Tata

We examine various aspects of supersymmetric particle production at linear $e^+e^-$ colliders operating at a centre of mass energy of $\sqrt{s}=500$ GeV, and integrated luminosity of $\int {\cal L}dt=20-50$ fb$^{-1}$. Working within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking (SU

A. Ali

These lectures review the progress made in our present understanding of $B$ decays. The emphasis here is on applications of QCD to $B$ decays and the attendant perturbative and non-perturbative uncertainties, which limit present theoretical precision in some cases but the overall picture that emerges is consistent with the standard model (SM). This is illust

Apostolos Pilaftsis

Brief overview of the present status on mixing and CP violation in kaons and B mesons is given by means of the unitarity triangle. Theoretical predictions on epsilon'/epsilon are confronted with experimental results. The prospects of detecting CP violation at high-energy p pbar, p p, e- e+ and mu- mu+ colliders are discussed in resonant scatterings invol

Abhijit Bhattacharyya, Jan-e Alam, Sibaji Raha, Bikash Sinha

Effects of finite temperature correction to the dilepton emission rate in ultrarelativistic heavy ion collisions have been looked into. It has been seen that although the $ρ$-peak in the dilepton spectra from the hadronic sector is suppressed at very high temperatures, almost no effect can be observed in the space time integrated count rate.

B. Geyer, D. Müller, D. Robaschik

The twist three contributions to the $Q^2$-evolution of the spin-dependent structure function $g_2(x)$ are considered in the non-local operator product approach. Starting from the perturbative expansion of the T-product of two electromagnetic currents, we introduce the nonlocal light-cone expansion proved by Anikin and Zavialov and determine the physical rel

A. A. Anselm, M. G. Ryskin

The probability distribution $dw/df$ as a function of the ratio $f=n_0/n_{tot}$ of the neutral to total multiplicities is calculated for the classical pion fields quickly varying in space and time.

V. A. Novikov

We consider the bounds for the values of higgs mass $m_H$ and the mass of the extra quarks and leptons $m_{extra}$ derived from the stability of electroweak vacuum and from the absence of Landau pole in Higgs potential. We find that in the case of the absence of new physics up to the GUT scale the bounds on masses of 4th generation are so strong that one can

J. J. Lodder

Gluons acquire a determinate mass from quark loop radiative corrrections and self-interaction, when these are recomputed with the symmetrical theory of generalised functions. The colour symmetry may be~$U(3)$ instead of~$SU(3)$. The symmetry breaks spontaneously and the ninth colour~$SU(3)$ singlet gluon acquires a very large mass. There may be some experime

J. R. Espinosa

These lectures provide a very basic introduction to different theoretical limits on the mass of Higgs scalars. Particular attention is devoted to the pure Standard Model and its Minimal Supersymmetric extension (MSSM). [Lectures presented at the XXIV ITEP Winter School, Snegiri (Russia), February 96]