August 1997 arXiv papers — page 6

H. Bachiri, L. Gilles, L. Vazquez

The paper has been temporarily withdrawn by the authors.

Daijiro Suematsu

We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $μ$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet Higgs. Focussing on its two lower mass eigenstates $\tildeχ_2^0$ and $\tildeχ_1^0$, decay processes such as a tree level

Jifeng Yang

A new approach is demonstrated that QFTs can be UV finite if they are viewed as the low energy effective theories of a fundamental underlying theory (that is complete and well-defined in all respects) according to the nowaday's standard point of view. No subtraction procedure, counter terms and hence bare parameters are needed. It can also be viewed as a

Jeremy S. Heyl, Lars Hernquist

Using recently calculated analytic models for the thermal structure of ultramagnetized neutron stars, we estimate the thermal fluxes from young ($t\sim 1000$ yr) ultramagnetized ($B \sim 10^{15}$ G) cooling neutron stars. We find that the pulsed X-ray emission from objects such as 1E 1841-045 and 1E 2259+586 as well as many soft-gamma repeaters can be explai

M. Protopapas, D. G. Lappas, P. L. Knight

We present a numerical method for investigating the non-perturbative quantum mechanical interaction of light with atoms in two dimensions, without a basis expansion. This enables us to investigate intense laser-atom interactions with light of arbitrary polarization without approximation. Results are presented for the dependence of ionization and high harmoni

Eric R. Bittner

We present an overview of the role of quantum coherence in influencing nonadiabatic processes in the condensed phase. Equations of motion for mixed quantum-classical dynamics are derived from the Consistent Histories interpretation of quantum mechanics. Application of the methods toward computing the excited state lifetime of an excess electron in water and

Eric R. Bittner, Peter J. Rossky

The role of quantum coherence loss in mixed quantum-classical dynamical systems is explored in the context of the theory of quantum decoherence introduced recently by Bittner and Rossky. (J. Chem. Phys. {\bf 103}, 8130 (1995)). This theory, which is based upon the consistent histories interpretation of quantum mechanics, introduces decoherence in the quantum

W. M. Kloet, B. Loiseau

A pi-pi, Kbar-K, and rho-rho(omega-omega) fully coupled channel model is used to predict the lowest isospin S, P, D, F-wave phase shifts and inelasticities for elastic pi-pi scattering from threshold to 2.0 GeV. As input the S-matrix is required to exhibit poles corresponding to the meson resonance table of the Particle Data Group. As expected, the pi-pi ine

A. D. Lahiff, I. R. Afnan

Equal-time Green's function is used to derive a three-dimensional integral equation from the Bethe-Salpeter equation. The resultant equation, in the absence of anti-particles, is identical to the use of time-ordered diagrams, and has been used within the framework of $ϕ^2σ$ coupling to study the role of energy dependence and non-locality when the two-bod

Peter E. Haagensen

The requirement that duality and renormalization group transformations commute as motions in the space of a theory has recently been explored to extract information about the renormalization flows in different statistical and field theoretical systems. After a review of what has been accomplished in the context of 2d sigma models, new results are presented w

C. Kohler

On the basis of the principle that topological quantum phases arise from the scattering around space-time defects in higher dimensional unification, a geometric model is presented that associates with each quantum phase an element of a transformation group.

Paolo Di Vecchia

In discussing the construction of a consistent theory of quantum gravity unified with the gauge interactions we are naturally led to a string theory. We review its properties and the five consistent supersymmetric string theories in ten dimensions. We finally discuss the evidence that these theories are actually special limits of a unique 11-dimensional theo

Shih-Yuin Lin, Kin-Wang Ng

We generalize the scale invariant gravity by allowing a negative kinetic energy term for the classical scalar field. This gives birth to a new scalar-tensor theory of gravity, in which the scalar field is in fact an auxiliary field. For a pure gravity theory without matter, the scale symmetric phase represents an equivalent class of gravity theories, which t

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

In this talk we go over several new developments regarding the techniques for a large class of non-hermitian matrix models with unitary randomness (complex random numbers). In particular, we discuss: (a) - A diagrammatic approach based on a $1/N$ expansion (b) - A generalization of the addition theorem (R-transformation) (c) - A conformal transformation on t

Kurt Riesselmann

This contribution reviews the latest results of the perturbative calculations of heavy-Higgs two-loop amplitudes. A comparison of perturbative results with nonperturbative lattice calculations is made, and the theoretical uncertainties of the lower and upper bound on the Standard Model Higgs mass are presented.

Thomas Hambye, Kurt Riesselmann

The two-loop Higgs mass upper bounds are reanalyzed. Previous results for a cutoff scale $Λ\approx$ few TeV are found to be too stringent. For $Λ=10^{19}$ GeV we find $M_H < 180 \pm 4\pm 5$ GeV, the first error indicating the theoretical uncertainty, the second error reflecting the experimental uncertainty due to $ m_t = 175 \pm 6 $ GeV. We also summarize th

T. Morii, D. Roy, K. Sudoh, Zuxun Sun

To test the color-octet model of heavy quarkonium productions, we propose $ψ&#39;$-productions at small-$p_T$ regions in polarized $pp$ collisions for the forthcoming RHIC polarized experiments, whose experimental test at $\sqrt s=50$ GeV might be very promising.

Bindu A. Bambah

We show that the sudden quenching mechanism responsible for the production of the disoriented chiral condensate gives rise automatically to squeezed states. We compare the distribution of charged and neutral pions in the two extreme limits of a sudden quench and a slow adiabatic relaxation and show that in the former case the difference in the distributions

M. Carrington, R. Kobes, E. Petitgirard

A resummation of ladder graphs is important in cases where infrared, collinear, or light-cone singularities render the loop expansion invalid, especially at high temperature where these effects are often enhanced. It has been noted in some recent examples of this resummation that the ladder graphs are canceled by other types of terms. In this note we show th

Shi-Lin Zhu, Ze-Sen Yang, W-Y. P. Hwang

We use QCD spectral sum rules to extract the Sigma_c and Lambda_c magnetic moments. The elctromagnetic field is treated as the external field. We adopt the value of the susceptibility chi=-4.5 GeV^{-2}, which is determined from an overall analysis of the octet baryon magnetic moments. Our result for Sigma_c is in agreement with the quark model prediction, wh

Z. Lalak

We analyze the structure of the vacuum and supersymmetry breaking pattern in Fayet-Iliopoulos models with dynamical gauge coupling and planck-scale value of the F-I parameter. We show that in this class of models supersymmetry is generically broken, but the mere presence of the D-term is not sufficient to stop the running away of the modulus responsible for

Kyungsik Kang, Sin Kyu Kang

We argue that the present value and accuracy of $M_W$ and $m_t$ measurements tend to favor the MSSM over the SM. By speculating that a precision of the order 40 MeV and 3 GeV respectively for $M_W$ and $m_t$ will be achieved at LEP2 and Tevatron, we show that the prospect for the MSSM will be further enhanced as long as the central values of $M_W$ and $m_t$

Shih-Yuin Lin, Kin-Wang Ng

A new scalar-tensor theory of gravity induced by dynamically broken scale invariance is proposed, and its cosmological implications are discussed. It is found that the model admits an inflation via the Hawking-Moss bubbling, but the inflation rate remains undetermined due to the strong gravity limit. In light of this, scale-invariant metric perturbations hav

J. Ambjørn, K. N. Anagnostopoulos, U. Magnea

We study the zeros in the complex plane of the partition function for the Ising model coupled to $2d$ quantum gravity for complex magnetic field and for complex temperature. We compute the zeros by using the exact solution coming from a two matrix model and by Monte Carlo simulations of Ising spins on dynamical triangulations. We present evidence that the ze

P. Lacock, C. Michael, P. Boyle, P. Rowland

We use lattice methods to evaluate from first principles the spectrum of hybrid mesons produced by gluonic excitations in quenched QCD with quark masses near the strange quark mass. For the spin-exotic mesons with $J^{PC}=1^{-+},\ 0^{+-}$, and $2^{+-}$ which are not present in the quark model, we determine the lightest state to be $1^{-+}$ with mass of 2.0(2

S. Marti i Garcia, J. Fuster, S. cabrera

The running mass of the b quark as defined in the MS-bar renormalization scheme, m_b, was measured at the M_Z scale using 2.8 million hadronic Z^0 decays collected by the DELPHI experiment at LEP. The result is m_b(M_Z) = 2.67 +- 0.25 (stat.) +- 0.34 (frag.) +- 0.27(theo.) GeV/c^2 which differs from that obtained at the Upsilon scale, by m_b(M_Υ/2)-m_b(M_Z)

F. Bunchaft, S. Carneiro

Velocity dependent forces varying as $k(\hat{r}/r)(1 - μ\dot{r}^2 + γr \ddot{r})$ (such as Weber force), here called Weber-like forces, are examined from the point of view of energy conservation and it is proved that they are conservative if and only if $γ=2μ$. As a consequence, it is shown that gravitational theories employing Weber-like forces cannot be co

Thomas Obermeier, Thomas Pruschke, Joachim Keller

We study the Hubbard model on a hypercubic lattice with regard to the possibility of itinerant ferromagnetism. The Dynamical Mean Field theory is used to map the lattice model on an effective local problem, which is treated with help of the Non Crossing Approximation. By investigating spin dependent one-particle Green&#39;s functions and the magnetic suscept

Parthapratim Biswas, Arnab Majumdar, Anita Mehta, J. K. Bhattacharjee

We present a set of coupled continuum equationswith a specific coupling between mobile grains $ρ$ and clusters $h$ on the surface of a sandpile. The equations are analysed self-consistently; we demonstrate that Edwards&#39; infrared divergence is responsible for the unexpected critical exponents we find, which are verified by simulations.

A. Barrat, S. Franz

We study the basins of attraction of metastable states in the spherical $p$-spin spin glass model, starting the relaxation dynamics at a given distance from a thermalized condition. Weighting the initial condition with the Boltzmann distribution we find a finite size for the basins. On the contrary, a white weighting of the initial condition implies vanishin

Andreas Werner, Friederike Schmid, Marcus Mueller, Kurt Binder

The interfacial profile between coexisting phases of a binary mixture (A,B) in a thin film of thickness D and lateral linear dimensions L depends sensitively on both linear dimensions and on the nature of boundary conditions and statistical ensembles applied. These phenomena generic for systems in confined geometry are demonstrated by Monte-Carlo simulations

E. Arrigoni, B. Brendel, W. Hanke

We study the low-temperature transport of a doped two-chain ladder system of interacting fermions in the presence of a barrier or of a low concentration of impurities. Above a certain value of the interaction, the conductance is suppressed, like for a single chain, despite the presence of dominant superconducting correlations. There is, however, a region of

E. V. Tsiper, A. L. Efros

We consider 2D gas of spinless fermions with the Coulomb and the short range interactions on a square lattice at T=0. Using exact diagonalization technique we study finite clusters up to 16 particles at filling factors $ν=1/2$ and 1/6. By increasing the hopping amplitude we obtain the low-energy spectrum of the system in a wide range from the classical Wigne

Debashish Chowdhury, Prabal K. Maiti

We review the models developed and techniques used in recent years to study the kinetics of phase ordering in a class of complex fluids, namely, ternary microemulsions and micellar solutions.

Jun-ichi Inoue

We apply the replica analysis established by Gardner to the multi-constraint continuous knapsack problem,which is one of the linear programming problems and a most fundamental problem in the field of operations research (OR). For a large problem size, we analyse the space of solution and its volume, and estimate the optimal number of items to go into the kna

Qijin Chen

Diamond nucleation under very low pressure (0.1-1.0 torr) was obtained at very high nucleation densities and very rapid rates using hot-filament chemical vapor deposition (HFCVD). The density on mirror-polished silicon was as high as 10^10 - 10^11 cm^{-2}, equivalent to the highest density in a microwave-plasma CVD system. That on scratched silicon substrate

Dmitri A. Ivanov, Patrick A. Lee

We present a low-energy effective model for the charge degrees of freedom in two-leg t-J ladders. Starting from SU(2) mean-field theory, we exclude the spin degrees of freedom which have an energy gap. At low temperatures, the mean-field solution is the staggered-flux phase. For gapless charge excitations the effective theory is the Luther-Emery liquid. Our

Khalil Sima&#39;an

This paper presents a new view of Explanation-Based Learning (EBL) of natural language parsing. Rather than employing EBL for specializing parsers by inferring new ones, this paper suggests employing EBL for learning how to reduce ambiguity only partially. The present method consists of an EBL algorithm for learning partial-parsers, and a parsing algorithm w

Neil Trentham

We present the luminosity function (LF) and measurements of the scalelengths, colours, and radial distribution of dwarf galaxies in the Coma cluster down to R=24. Our survey area is 674 arcmin^2; this is the deepest and most detailed survey covering such a large area. Our measurements agree with those of most previous authors at bright and intermediate magni

Ulrich Kolb

I discuss population synthesis methods in the context of low-mass compact binaries. Two examples, both constraining the largely unknown strength of orbital angular momentum losses, illustrate the power and problems of such studies. For CVs, the ``standard&#39;&#39; disrupted magnetic braking model predicts that systems below the period gap are on average old

Neil Trentham

We present the results from a CCD survey of the B-band luminosity functions of 9 nine clusters of galaxies, and compare them with published photographic luminosity functions of nearby poor clusters like Virgo and Fornax and also to the field luminosity function. We derive a composite luminosity function by taking the weighted mean of all the individual clust

Joseph Silk, Marco Spaans

Models are presented for CO rotational line emission by high redshift starburst galaxies. The influence of the cosmic microwave background on the thermal balance and the level populations of atomic and molecular species is explicitly included. Predictions are made for the observability of starburst galaxies through line and continuum emission between z=5 and

Sukyoung Yi, Pierre Demarque, Augustus Oemler,

Whether or not metal-rich HB stars are the dominant UV source in giant elliptical galaxies (gEs) is an important question in current astronomical research. We follow up our previous evolutionary population synthesis study with quantitative tests to answer this question affirmatively under the following three conditions: (1) Reimers&#39; empirical mass loss f

K. S. de Boer, Y. Aguilar Sanchez, M. Altmann, M. Geffert

The spatial distribution and the population nature of subdwarf B type stars in the galaxy is investigated based on the kinematics of these stars. The orbits of 41 stars have been calculated using a galactic mass model. These are well behaved and 10 stars reach to |z| > 2 kpc. Many orbits are very eccentric, reaching in to just 2 kpc from the galactic centre,

M. H. Salamon, F. W. Stecker

We extend earlier calculations of the attenuation suffered by gamma rays during their propagation from extragalactic sources, obtaining new extinction curves for gamma rays down to 10 GeV in energy, from sources up to a redshift of z=3.

V. G. Bezchastnov, P. Haensel, A. D. Kaminker, D. G. Yakovlev

We study the synchrotron emission of neutrino pairs by relativistic, degenerate electrons in strong magnetic fields. Particular attention is paid to the case in which the dominant contribution comes from one or several lowest cyclotron harmonics. Calculations are performed using the exact quantum formalism and the quasiclassical approach. Simple analytic fit

Sangeeta Malhotra

The broad absorption bump at 2175 angstrom due to dust, which is ubiquitous in the Galaxy and is seen in the Magellanic clouds, is also seen in a composite spectrum of Mg II absorbers. The composite absorber spectrum is obtained by taking the geometric mean of 92 quasar spectra after aligning them in the restframe of 96 absorbers. By aligning the spectra acc

R. Canal, J. Isern, P. Ruiz-Lapuente

The suggestion that roughly half the mass of the galactic halo might be in the form of white dwarfs, together with the limits on the infrared background light and on the initial metallicity of the galactic disk, would set strong constraints on the initial mass function (IMF) of the halo. Particular IMFs have been proposed to cut off both the numbers of low-m

David W. Hogg, E. S. Phinney

Dwarf, irregular and infrared-luminous starburst galaxies are all known to have &#34;steep&#34; luminosity functions with faint-end behavior roughly phi(L)-propto- L^(-1.8). This form is exactly what is expected if the luminosities of these objects fade with time as L-propto-t^(-1.3), because the objects spend more time at low luminosities than high, even if

B. Shapiro, M. Shapiro

In this short note we give an explicit presentation of the algebra A_n generated by the curvature 2-forms of the standard Hermitiam line bundles over SL_n/B as the quotient of the polynomial ring. The difference between A_n and H^*(SL_n/B) reflects the fact that SL_n/B is not a symmetric space. Possible applications of A_n lie in the field of arithmetic inte

V. Zaborovski, S. Yegorov, Y. Podgurski, Y. Shemanin

The main steps of automatic control methodology include the hierarchical representation of management system and the formal definitions of input variables, object and goal of control of each management level. A Petri net model of individual traffic source is presented. It is noted that the current set of traffic parameters recommended by ATM-forum is not eno

Andrey V. Kravtsov, Anatoly A. Klypin, James S. Bullock, Joel R. Primack

We use the rotation curves of a sample of dark matter dominated dwarf and low-surface brightness (LSB) late-type galaxies to study their radial mass distributions. We find that the shape of the rotation curves is remarkably similar for all (both dwarf and LSB) galaxies in the sample, suggesting a self-similar density distribution of their dark matter (DM) ha

Ping Xu

The purpose of this Note is to unify quantum groups and star-products under a general umbrella: quantum groupoids. It is shown that a quantum groupoid naturally gives rise to a Lie bialgebroid as a classical limit. The converse question, i.e., the quantization problem, is posed. In particular, any regular triangular Lie bialgebroid is shown quantizable. For

W. A. Sabra

We construct general static black hole configuration for the theory of N=2, d=5 supergravity coupled to an arbitrary number of Abelian vector multiplets. The underlying very special geometry structure plays a major role in this construction. From the viewpoint of M-theory compactified on a Calabi-Yau threefold, these black holes are identified with BPS windi

S. P. Mikheyev, A. Yu. Smirnov

Long length vacuum oscillations solution of the solar neutrino problem is discussed. We show that there is a strict correlation between a distortion of the neutrino energy spectrum and an amplitude of seasonal variations of the neutrino flux. The slope parameter which characterizes a distortion of the recoil electron energy spectrum in the Super-Kamiokande e

Nazeem Mustapha, B. A. Bassett, Charles Hellaby, G. F. R. Ellis

This paper and the others in the series challenge the standard model of the effects of gravitational lensing on observations at large distances. We show that due to the cumulative effect of lensing, areas corresponding to an observed solid angle can be quite different than would be estimated from the corresponding Friedmann-Lema\^ıtre model, even when averag

Giovanni Landi, Carlo Rovelli

We study a formulation of euclidean general relativity in which the dynamical variables are given by a sequence of real numbers $λ_{n}$, representing the eigenvalues of the Dirac operator on the curved spacetime. These quantities are diffeomorphism-invariant functions of the metric and they form an infinite set of ``physical observables&#39;&#39; for general

Klaus Hulek

We determine the cone of nef divisors on the Voronoi compactification A_g^* of the moduli space A_g of principally polarized abelian varieties of dimension g for genus g=2,3. As a corollary we obtain that the spaces A_g^*(n) with level-n structure are a minimal, resp. canonical, model for g=2, n>=4, resp. n>=5 and g=3, n>=3, resp. n>=4. We give two proofs: T

Holger F. Hofmann, Ortwin Hess, Guenter Mahler

We show that the influence of quantum fluctuations in the electromagnetic field vacuum on a two level atom can be measured and consequently compensated by balanced homodyne detection and a coherent feedback field. This compensation suppresses the decoherence associated with spontaneous emission for a specific state of the atomic system allowing complete cont

Damien Challet, Yi-Cheng Zhang

A binary game is introduced and analysed. N players have to choose one of the two sides independently and those on the minority side win. Players uses a finite set of ad hoc strategies to make their decision, based on the past record. The analysing power is limited and can adapt when necessary. Interesting cooperation and competition pattern of the society s

H. W. Lee, Y. S. Myung, Jin Young Kim

We discuss the role of fixed scalars($ν,λ$) in scattering off a five-dimensional balck hole. The issue is to explain the disagreement of the greybody factor for $λ$ between the semiclassical and effective string calculations. In the effective string approach, this is related to the operators with dimension (3,1) and (1,3). On the semiclassical calculation, t

Benjamin Grinstein, Richard F. Lebed

We compute the nonleptonic weak decay width of a heavy-light meson in 1+1 spacetime dimensions with a large number of QCD colors (the &#39;t Hooft model) as a function of the heavy quark mass. In this limit, QCD is exactly soluble, and decay modes are dominated by two-particle final states. We compare the results to the tree-level partonic decay width of the

S. J. van Enk, J. I. Cirac, P. Zoller

Using a cavity QED setup we show how to implement a particular joint measurement on two atoms in a fault tolerant way. Based on this scheme, we illustrate how to realize quantum communication over a noisy channel when local operations are subject to errors. We also present a scheme to perform and purify a universal two-bit gate.

Stavros Garoufalidis

The purpose of this note is to unify the role of the lantern identity in the proof of several finiteness theorems. In particular, we show that for every nonnegative integer m, the vector space (over the rationals) of type m (resp. T-type m) invariants of integral homology 3-spheres are finite dimensional. These results have already been obtained by [Oh] and

Masatoshi Noumi, Yasuhiko Yamada

We propose a new representation of the fourth Painlevé equation in which the $A^{(1)}_2$-symmetries become clearly visible. By means of this representation, we clarify the internal relation between the fourth Painlevé equation and the modified KP hierarchy. We obtain in particular a complete description of the rational solutions of the fourth Painlevé equati

A. B. Balantekin, N. Takigawa

Recent theoretical advances in the study of heavy ion fusion reactions below the Coulomb barrier are reviewed. Particular emphasis is given to new ways of analyzing data, such as studying barrier distributions; new approaches to channel coupling, such as the path integral and Green function formalisms; and alternative methods to describe nuclear structure ef

S. R. Beane, V. Bernard, T. -S. H. Lee, Ulf-G. Meißner

We consider constraints on the isoscalar S-wave pi-N scattering length a+ from pi-deuteron scattering, to third order in small momenta and pion masses in chiral perturbation theory. To this order, the pi-deuteron scattering length is determined by a+ together with three-body corrections that involve no undetermined parameters. We extract a novel value for a

A. Cobis, D. V. Fedorov, A. S. Jensen

We solve the Faddeev equations for 11Li (n+n+9Li) using hyperspherical coordinates and analytical expressions for distances much larger than the effective ranges of the interactions. The lowest resonances are found at 0.65 MeV (1/2+, 3/2+, 5/2+) and 0.89 MeV (3/2+, 3/2-) with widths of about 0.35 MeV. A number of higher-lying broader resonances are also obta

L. P. Csernai, S. Jeon, J. I. Kapusta

Coarse-grained Langevin-type effective field equations are derived for classical systems of particles. These equations include the effects of thermal fluctuation and dissipation which may arise from coupling to an external bath, as in the Brownian motion of a single particle, or which may arise from statistical fluctuations in small parts of an isolated many

Diego A. R. Dalvit, Francisco D. Mazzitelli

When graviton loops are taken into account, the background metric obtained as a solution to the one-loop corrected Einstein equations turns out to be gauge fixing dependent. Therefore it is of no physical relevance. Instead we consider a physical observable, namely the trajectory of a test particle in the presence of gravitons. We derive a quantum corrected

Stephen Hwang

We study in detail the semi-infinite or BRST cohomology of general affine Lie algebras. This cohomology is relevant in the BRST approach to gauged WZNW models. We prove the existence of an infinite sequence of elements in the cohomology for non-zero ghost numbers. This will imply that the BRST approach to topological WZNW model admits many more states than a

Edmond L. Berger, Xiaofeng Guo, Jianwei Qiu

We show that the conventionally defined partonic cross section for the production of isolated prompt photons is not an infrared safe quantity. We work out the case of $e^+e^- \to γ+ X$ in detail, and we discuss implications for hadron reactions such as $p \bar{p} \to γ+ X$.

E. Keith, Ernest Ma

If an extra supersymmetric U(1) gauge factor exists at the TeV energy scale, which is then broken together with the supersymmetry, there will be several interesting and important phenomenological consequences, not only at the TeV scale, but also at the 100 GeV scale. For one, the generic two-doublet Higgs structure will involve 3 additional parameters beyond

Ernest Ma

At greater than nuclear densities, matter may convert into a mixture of nucleons, hyperons, dibaryons, and strangelets, thus facilitating the formation of strange matter even before the onset of the quark-matter phase transition. From a nonstrange dibaryon condensate, it may even be possible to leapfrog into strange matter with a certain new interaction, rep

L. Clavelli, Gary R. Goldstein

The Fermilab top quark analysis is heavily dependent on the assumption of standard model backgrounds only. In the light gluino scenario, the stop quarks lie near the top in mass and their decays can influence the resulting top quark mass by an amount that is not small relative to the currently quoted errors. Several slight anomalies in the top quark analysis

George Sterman

Some of the experimental and theoretical results discussed at the Fifth International Workshop on Deep Inelastic Scattering and QCD are reviewed.

H. -J. He, Y. -P. Kuang, C. -P. Yuan

We classify the sensitivities of the future high energy hadron and electron colliders, such as the LHC and the future Linear Colliders, to probing all the next-to-leading order (NLO) bosonic operators for studying the electroweak symmetry breaking (EWSB) mechanism. We first develop a power counting rule (a generalization of Weinberg&#39;s counting method for

Daniel F. Litim

We analyse the finite temperature phase transition of scalar QED in euclidean spacetime. Analytical solutions of approximations to a Wilsonian renormalisation group equation are discussed. Special emphasis is put on the discussion of the $3d$ running of the Abelian charge and its effects on thermodynamical quantities. An upper bound for the range of first-or

J. M. Cline

I describe work done in collaboration with M. Joyce and K. Kainulainen on (1) the strength of the electroweak phase transition in the MSSM and (2) the mechanism for producing the baryon asymmetry during the phase transition. In the former we compare the effective potential and dimensional reduction methods for describing the phase transition and search the p

Yuval Grossman, Boris Kayser, Yosef Nir

CP asymmetries in $B$ decays into final CP eigenstates are in many cases theoretically clean. In particular, they do not depend on the values of hadronic parameters. The sign of the asymmetries, however, does depend on the sign of the $B_B$ parameter. Furthermore, the information from $ε_K$ that all angles of the unitarity triangles lie in the range $\{0,π\}

T. Fukuyama, K. Matsuda, H. Nishiura

We argue three-flavour neutrino mixing. We consider the neutrinos as Majorana particles and see how the neutrinoless double beta decay constrains the neutrino mixing angles. Our formulation is widely valid and is applied to the neutrino oscillation experiment.

A. M. Green, P. Pennanen, C. Michael

Action and energy flux-tube profiles are computed, in SU(2) with beta=2.4,2.5, for two quarks up to 1 fm apart and for which the colour fields are in their ground state (A_1g) and the first (E_u) and higher (A&#39;_1g) excited gluonic states. When these profiles are integrated over all space, a scaling comparison is made between the beta=2.4 and 2.5 data. Us

A. Cruz, D. Iñiguez, L. A. Fernández, A. Muñoz-Sudupe

The order of the Coulomb-Higgs transition in the U(1)-Higgs model with unfrozen modulus of the scalar field is studied. Large lattices (up to $24^4$ in one case) and high statistics are used. We fix $β=1.15$ and explore specially a region of $λ$-values where metastability is observed. We study the thermodynamical limit of several observables, in particular,

JLQCD Collaboration, S. Aoki, M. Fukugita, S. Hashimoto

Report is made of a systematic scaling study of the finite-temperature chiral phase transition of two-flavor QCD with the Kogut-Susskind quark action based on simulations on $L^3\times4$ ($L$=8, 12 and 16) lattices at the quark mass of $m_q=0.075, 0.0375, 0.02$ and 0.01. Our finite-size data show that a phase transition is absent for $m_q\geq 0.02$, and quit

The OPAL Collaboration, K. Ackerstaff et al

Gluon jets are identified in e+e- hadronic annihilation events by tagging two quark jets in the same hemisphere of an event. The gluon jet is defined inclusively as all the particles in the opposite hemisphere. Gluon jets defined in this manner have a close correspondence to gluon jets as they are defined for analytic calculations, and are almost independent

The OPAL Collaboration, K. Ackerstaff et al

Deep inelastic electron-photon scattering is studied using e+e- data collected by the OPAL detector at centre-of-mass energies sqrt{s_ee} ~ M_{Z^0}. The photon structure function F_2^gamma(x,Q^2) is explored in a Q^2 range of 1.1 to 6.6 GeV/c^2 at lower x values than ever before. To probe this kinematic region events are selected with a beam electron scatter

The OPAL Collaboration, K. Ackerstaff et al

The longitudinal polarization, the transverse polarization, and the forward-backward asymmetry of Lambda baryons have been measured using a sample of 4.34 million hadronic Z^0 decays collected with the OPAL detector at LEP between 1990 and 1995. These results are important as an aid to the understanding of hadronization mechanisms. Significant longitudinal p

Filipe M. Paiva, Marcelo J. Reboucas, Graham S. Hall, Malcolm A. H. MacCallum

A limiting diagram for the Segre classification of the energy-momentum tensor is obtained and discussed in connection with a Penrose specialization diagram for the Segre types. A generalization of the coordinate-free approach to limits of Paiva et al. to include non-vacuum space-times is made. Geroch&#39;s work on limits of space-times is also extended. The

Pedro F. Gonzalez-Diaz

Assuming that spacetime tunnels -wormholes and ringholes- naturally exist in the universe, we investigate the conditions making them embeddible in Friedmann space, and the possible observable effects of these tunnels, including: lensing and frequency-shifting of emitting sources, discontinuous change of background temperature, broadening and intensity enhanc

Peter Huebner

Recently Bernd Schmidt has given three explicit examples of spacetimes with toroidal null infinities. In this paper all solutions with a toroidal null infinity within Schmidt&#39;s metric ansatz (polarized Gowdy models) are constructed. The members of the family are determined by two smooth functions of one variable. For the unpolarized Gowdy models the same

J. Erdmenger, H. Osborn

We extend previous work on conformally covariant differential operators to consider the case of second order operators acting on symmetric traceless tensor fields. The corresponding flat space Green function is explicitly constructed and shown to be in accord with the requirements of conformal invariance.

Leo Brewin

A new hybrid scheme for numerical relativity will be presented. The scheme will employ a 3-dimensional spacelike lattice to record the 3-metric while using the standard 3+1 ADM equations to evolve the lattice. Each time step will involve three basic steps. First, the coordinate quantities such as the Riemann and extrinsic curvatures are extracted from the la

W. J. Nellis, A. A. Louis, N. W. Ashcroft

The electrical resistivity of liquid hydrogen has been measured at the high dynamic pressures, densities and temperatures that can be achieved with a reverberating shock wave. The resulting data are most naturally interpreted in terms of a continuous transition from a semiconducting to a metallic, largely diatomic fluid, the latter at 140 GPa, (ninefold comp

Pierre Cizeau, Yanhui Liu, Martin Meyer, C. -K. Peng

We study the volatility of the S&P500 stock index from 1984 to 1996 and find that the volatility distribution can be very well described by a log-normal function. Further, using detrended fluctuation analysis we show that the volatility is power-law correlated with Hurst exponent $α\cong0.9$.

U. Nowak, K. D. Usadel, J. Esser

We investigate the low-temperature critical behavior of the three dimensional random-field Ising ferromagnet. By a scaling analysis we find that in the limit of temperature $T \to 0$ the usual scaling relations have to be modified as far as the exponent $α$ of the specific heat is concerned. At zero temperature, the Rushbrooke equation is modified to $α+ 2 β

Tsutomu Momoi, Kenn Kubo, Koji Niki

We study a spin system with two- and four-spin exchange interactions on the triangular lattice, which is a possible model for the nuclear magnetism of solid $^3$He layers. It is found that a novel spin structure with scalar chiral order appears if the four-spin interaction is dominant. Ground-state properties are studied using the spin-wave approximation. A

Kenn Kubo, Tsutomu Momoi

We study a spin system with both two- and four-spin exchange interactions on the triangular lattice as a possible model for the nuclear magnetism of solid $^3$He layers adsorbed on grafoil. The ground state is analyzed by the use of the mean-field approximation. It is shown that the four-sublattice state is favored by introduction of the four-spin exchange i

R. J. Dodd, M. Edwards, C. W. Clark, K. Burnett

We have applied the Popov version of the Hartree-Fock-Bogoliubov (HFB) approximation to calculate the finite-temperature excitation spectrum of a Bose-Einstein condensate (BEC) of $^{87}$Rb atoms. For lower values of the temperature, we find excellent agreement with recently-published experimental data for the JILA TOP trap. In contrast to recent comparison

Pierre-Antoine Rey, Michel Droz, Jaroslaw Piasecki

We study the kinetics of ballistic annihilation for a one-dimensional ideal gas with continuous velocity distribution. A dynamical scaling theory for the long time behavior of the system is derived. Its validity is supported by extensive numerical simulations for several velocity distributions. This leads us to the conjecture that all the continuous velocity

Pierpaolo Bruscolini

We test a simplified, local version of the helix model on two synthetic and two natural proteins, to study its efficiency in predicting the native secondary structure. The results we obtain are very good for the synthetic sequences, poorer for the two natural ones. This suggests that non-local terms play a fundamental role in determining the secondary struct