August 1997 arXiv papers — page 8

The OPAL Collaboration, K. Ackerstaff et al

A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 10.3 pb^-1 at centre-of-mass energies of sqrt(s) = 170 and 172 GeV with the OPAL detector at LEP. No evidence for these particles has been found. The results are combined with those from previous OPAL chargino and neutralino searches at low

A. Vecchio, B. Bertotti, L. Iess

We discuss the sensitivity of the CASSINI experiments to gravitational waves emitted by the in-spiral of compact binaries. We show that the maximum distance reachable by the instrument is $\sim 100$ Mpc. In particular, CASSINI can detect massive black hole binaries with chirp mass $\simgt 10^6 \Ms$ in the Virgo Cluster with signal-to-noise ratio between 5 an

Martin B. Tarlie, Alan J. McKane

We consider the problem of state selection for a stochastic system, initially in an unstable stationary state, when multiple metastable states compete for occupation. Using path-integral techniques we derive remarkably simple and accurate formulas for state-selection probabilities. The method is sufficiently general that it is applicable to a wide variety of

Mark P. Taylor, J. E. G. Lipson

The equilibrium properties of a tangent-hard-sphere polymer chain in a hard sphere monomer solvent are studied using a Born-Green-Yvon integral equation in conjunction with a two-site solvation potential. The solvation potential is constructed using low density results for a hard-sphere trimer in a hard sphere solvent. The BGY equation has been solved for po

J. Luettmer-Strathmann, J. E. G. Lipson

Phase separation in mixtures of polymers and alkanes is investigated with the aid of a recently developed lattice model, based on the Born-Green-Yvon (BGY) integral equation approach to fluids. The system-dependent parameters of the BGY lattice model for binary mixtures are deduced from those of its pure components, which in turn are determined from a compar

V. I. Yukalov, S. Gluzman

A variant of self-similar approximation theory is suggested, permitting an easy and accurate summation of divergent series consisting of only a few terms. The method is based on a power-law algebraic transformation, whose powers play the role of control functions governing the fastest convergence of the renormalized series. A striking relation between the th

Sang Boo Nam

It is shown that the notion of the finite pairing interaction energy range $T_d$ results in a linear temperature dependence of the London magnetic penetration depth $Δλ/ λ(0) = (T/T_d)(2/π)\ln 2$ at low temperature, in the case of the s-wave pairing state.

Todd A. Small, Chung-Pei Ma, Wallace L. W. Sargent, Donald Hamilton

(Abridged) We present a study of the structure and dynamics of the Corona Borealis Supercluster (z ~ 0.07) based on the redshifts for 528 galaxies in the supercluster. The galaxy distribution within Corona Borealis is clumpy and appears overall to be far from relaxed. A background supercluster at z ~ 0.11 makes a substantial contribution to the projected sur

Z. Guralnik, S. Ramgoolam

The moduli space of 0-branes on $T^4$ gives a prediction for the moduli space of torons in U(n) Super Yang Mills theory which preserve 16 supersymmetries. The zero brane number corresponds to the greatest common denominator of the rank $n$, magnetic fluxes and the instanton number. This prediction is derived using U-duality. We explicitly check this predicti

Luis Gonzalez-Mestres

If textbook Lorentz invariance is actually a property of the equations describing a sector of the excitations of vacuum above some critical distance scale, several sectors of matter with different critical speeds in vacuum can coexist and an absolute rest frame (the vacuum rest frame) may exist without contradicting the apparent Lorentz invariance felt by &#

P. Maris, C. D. Roberts

Independent of assumptions about the form of the quark-quark scattering kernel, K, we derive the explicit relation between the flavour-nonsinglet pseudoscalar meson Bethe-Salpeter amplitude, Gamma_H, and the dressed-quark propagator in the chiral limit. In addition to a term proportional to gamma_5, Gamma_H necessarily contains qualitatively and quantitative

F. Abe, The CDF Collaboration

We present a search for first generation leptoquark with 110pb^1 of data collected with the CDF detector. We set 95% C.L. cross section limits as a function of the leptoquark mass.

P. T. Coleridge, R. L. Williams, Y. Feng, P. Zawadzki

Observations are reported of a metal-insulator transition in a 2D hole gas in asymmetrically doped strained SiGe quantum wells. The metallic phase, which appears at low temperatures in these high mobility samples, is characterised by a resistivity that decreases exponentially with decreasing temperature. This behaviour, and the duality between resistivity an

Thorsten Emig, Thomas Nattermann

We study the competition between pinning of a charge density wave (CDW) by random distributed impurities and a periodic potential of the underlying crystal lattice. In d=3 dimensions, we find for commensurate phases of order p>p_c\approx 6/πa disorder driven continuous roughening transition from a 'flat' phase with translational long range order to a

Marek Czachor, Maciej Kuna

Simple Hartree-type equations lead to dynamics of a subsystem that is not completely positive in the sense accepted in mathematical literature. In the linear case this would imply that negative probabilities have to appear for some system that contains the subsystem in question. In the nonlinear case this does not happen because the mathematical definition i

Takeshi Chiba, Naoshi Sugiyama, Jun'ichi Yokoyama

Spectra of density perturbations produced during chaotic inflation are calculated, taking both adiabatic and isocurvature modes into account in a class of scalar-tensor theories of gravity in which the dilaton is metrically coupled. Comparing the predicted spectrum of the cosmic microwave background radiation anisotropies with the one observed by the COBE-DM

Magaret E. Carrington, Hou Defu, Markus H. Thoma

We investigate the use of the hard thermal loop (HTL) resummation technique in non-equilibrium field theory. We use the Keldysh representation of the real time formalism (RTF). We derive the HTL photon self energy and the resummed photon propagator. We show that no pinch singularities appear in the non-equilibrium HTL effective propagator. We discuss a possi

Lubos Motl, Leonard Susskind

The finite N version of Matrix theory describes M-theory and superstrings in so-called discretized light cone quantization (DLCQ). Its role has been explained for M-theory in 11 dimensions and for type IIA theory. We show novelties which arise by generalizing the ideas to heterotic strings. The states which arise in O(N) theories with odd N we interpret as f

D. R. Phillips, S. J. Wallace

A formalism is presented which allows covariant three-dimensional bound-state equations to be derived systematically from four-dimensional ones without the use of delta-functions. The amplitude for the interaction of a bound state described by these equations with an electromagnetic probe is constructed. This amplitude is shown to be gauge invariant if the f

Oe. Elgaroey, M. Hjorth-Jensen

We consider 1S0 pairing in infinite neutron matter and nuclear matter and show that in the lowest order approximation, where the pairing interaction is taken to be the bare nucleon-nucleon (NN) interaction in the 1S0 channel, the pairing interaction and the energy gap can be determined directly from the 1S0 phase shifts. This is due to the almost separable c

Roberto G. Ferretti

In this paper we improve drastically the estimate for the multiplicity of a binary recurrence. The main contribution comes from an effective version of the Faltings' Product Theorem.

Eric C. Milner, Saharon Shelah

We answer a variant of a question of Rodl and Voigt by showing that, for a given infinite cardinal lambda, there is a graph G of cardinality kappa =(2^lambda)^+ such that for any colouring of the edges of G with lambda colours, there is an induced copy of the kappa-tree in G in the set theoretic sense with all edges having the same colour.

James T. Wheeler

The zero-signature Killing metric of a new, real-valued, 8-dimensional gauging of the conformal group accounts for the complex character of quantum mechanics. The new gauge theory gives manifolds which generalize curved, relativistic phase space. The difference in signature between the usual momentum space metric and the Killing metric of the new geometry gi

Andras Kaiser, Stephen B. Selipsky

Solutions of the superspace Schwinger-Dyson equations, describing mass generation and chiral symmetry breaking in supersymmetric gauge theory, need not be constrained to vanish by no-renormalization theorems, nor by special choices of gauge parameter. Thus symmetry breaking vacuum structures remain possible (as in non-supersymmetric gauge theory), inviting c

Ruth Gregory, Jeffrey A. Harvey, Gregory Moore

A fundamental string with non-zero winding number can unwind in the presence of a Kaluza-Klein monopole. We use this fact to deduce the presence of a zero mode for the Kaluza-Klein monopole corresponding to excitations carrying H electric charge and we study the coupling of this zero mode to fundamental strings. We also a describe a T-dual process in which t

Nathan Seiberg, Savdeep Sethi

We study the theory of NS five-branes in string theory with a smooth non-trivial transverse space. We show that in the limit that the bulk physics decouples, these theories become equivalent to theories with a flat and non-compact transverse space. We present a matrix model description of the type IIA theory on $\IR^9\times S^1$ with NS five-branes located a

Oliver DeWolfe

We use minimal area metrics to generate all nonorientable string diagrams. The surfaces in unoriented string theory have nontrivial open curves and nontrivial closed curves whose neighborhoods are either annuli or Mobius strips. We define a minimal area problem by imposing length conditions on open curves and on annular closed curves only. We verify that the

G. Jikia

Recent progress in calculating O(alpha) electroweak corrections to W+W- pair production in photon-photon collisions is reviewed. The potential of the Photon Linear Collider to study anomalous W couplings is discussed.

Andrzej Czarnecki, Kirill Melnikov, Nikolaj Uraltsev

Dipole radiation in QCD is derived to the second order in $α_s$. A power-like evolution of the spin-singlet heavy quark operators is obtained to the same accuracy. In particular, ${\cal O}(α_s^2)$ relation between a short-distance low-scale running heavy quark mass and the $\barMS$ mass is given. We discuss the properties of the effective QCD coupling $\aw(E

Nora Brambilla, Antonio Vairo

We study the $q \bar{q}$ relativistic interaction starting from the Feynman-Schwinger representation of the gauge-invariant quark-antiquark Green function. We focus on the one-body limit and discuss the obtained non-perturbative interaction kernel of the Dirac equation.

George Sterman, Paul Stoler

The electromagnetic form factors of hadrons at large momentum transfer have been the subject of intense theoretical and experimental scrutiny over the past two decades, yet there is still not a universally-accepted framework for their description. This review is a synopsis of their current status at large momentum transfer. The basic theoretical approaches t

Duane A. Dicus, Rabindra N. Mohapatra, Vigdor L. Teplitz

In supergravity models with low supersymmetry breaking scale the gravitinos can be superlight with mass in the micro-eV to keV range. In such a case, gravitino emission provides a new cooling mechanism for protoneutron stars and therefore can provide constraints on the mass of the superlight gravitino. This happens because the coupling to matter of superligh

Christophe Le Mouel, Gilbert Moultaka

We study, in the Minimal Supersymmetric Standard Model, the electroweak symmetry breaking conditions obtained from the one-loop effective potential. Novel model-independent lower and upper bounds on $\tan β$, involving the other free parameters of the model, are inferred and determined analytically. We discuss briefly some of the related issues and give an o

S. Groote, J. G. Körner, J. A. Leyva

We calculate the $O(α_s)$ corrections to longitudinal spin-spin correlations in $e^+e^-\to q\bar q$. For top quark pair production the $O(α_s)$ corrections to the longitudinal spin-spin asymmetry amount to less than 1% in the $q^2$-range from above $t\bar t$-treshold up to $\sqrt{q^2}= 1000 GeV$. In the $e^+e^-\to b\bar b$ case the $O(α_s)$ corrections reduc

H. Fritzsch, Z. Z. Xing

It is shown that there exist nine different ways to describe the flavor mixing, in terms of three rotation angles and one CP-violating phase, within the standard electroweak theory of six quarks. For the assignment of the complex phase there essentially exists a continuum of possibilities, if one allows the phase to appear in more than four elements of the m

Boris Krippa

The effect of mixing of the vector and axial vector correlation functions in the nuclear medium arising from the interaction of nuclear pions with corresponding interpolating currents is considered. It is shown that the mass difference between $ρ$ and $a_1$ meson gets smaller with the increase of the nuclear density reflecting the phenomena of partial restor

Gia Dvali, Alex Pomarol

We study the breaking of supersymmetry in models with anomalous U(1). These models are simple to construct and contain natural candidates for being the messengers of gauge-mediated supersymmetry breaking. When some of the ordinary matter fields transform under the anomalous U(1), we find a hybrid scenario in which the U(1) and the gauge interactions mediate

Dirk Graudenz

The status of the calculation of next-to-leading-order QCD corrections to hadronic final states in deeply inelastic scattering is reviewed, and an overview of the phenomenology (including the measurement of the strong coupling constant and the gluon density via jet rates) is given. We also describe a new universal program (DISASTER++) for the calculation of

Jonathan L. Feng

If supersymmetry is discovered at future colliders, what can we learn? While our appreciation of the variety of possible supersymmetric models has grown tremendously in recent years, most attempts to answer this question have been in the context of some simple and highly restrictive framework, such as minimal supergravity. In this talk I describe new probes

D. B"odeker

In order to investigate the reliability of the classical approximation for non-perturbative real time correlation functions at finite temperature we study the two-point correlator for the anharmonic oscillator. For moderately large times the classical limit gives a good approximation of the quantum result but after some time $t_*$ the classical approximation

Steen H. Hansen

We clarify that one cannot distinguish between Majorana and Dirac neutrinos in the limit of vanishing neutrino mass. In particular we show, that the forward-backward asymmetry in the reaction e^+ e^- -> ννis the same for ν_M and ν_D, in contrast to recent claims made in the literature.

S. Bar-Shalom, G. Eilam, A. Soni, J. Wudka

The Standard Model with one extra Higgs doublet may give rise to enhanced TREE-LEVEL flavor-changing-scalar coupling of a neutral Higgs to a pair of top-charm quarks. This coupling may drive a large TREE-LEVEL effective W^+W^-(ZZ) - Higgs - t c-bar interaction. As a result we find that the reactions e^+e^- -> t c-bar ν_e ν_e-bar, t c-bar e^+ e^-, t c-bar Z a

S. Bar-Shalom, D. Atwood, A. Soni

CP-nonconserving effects in the reaction p p-bar -> t b-bar +X -> W^+ b b-bar +X, driven by the supersymmetric CP-odd phase of the stop trilinear soft breaking term, \arg(A_t), are studied. We discuss the CP-nonconserving effects in both production and the associated decay amplitudes of the top. We find that, within a plausible low energy scenario of the MSS

C. S. Kim, D. London, T. Yoshikawa

Dighe, Gronau and Rosner have shown that, by assuming SU(3) flavor symmetry and first-order SU(3) breaking, it is possible to extract the CP angles αand γfrom measurements of the decay rates of B_d^0(t) --> π^+π^-, B_d^0 --> π^- K^+ and B^+ --> π^+ K^0, along with their charge-conjugate processes. We extend their analysis to include the SU(3)-related decays

Chi-Keung Chow, Soo-Jong Rey

Interactions of $a_2, K^*_2, f_2$ and $f_2'$ tensor-mesons with low-energy $\pi, K, \eta, \eta'$ pseudo-scalar mesons are constrained by chiral symmetry. We derive a chiral Lagrangian of tensor mesons in which the tensor mesons are treated as heavy non-relativistic matter fields. Using $1/N_c$ counting, we derive relations among unknown couplings of the chir

M. Yoshimura

The problem of unstable particle decay is discussed to show how elementarity of a subsystem immersed in an infinitely larger environment is lost. The decay law, when the same kind of particles as decay product make up a thermal medium, is worked out in detail. The relic abundance of unstable particles does not suffer from the Boltzmann suppression crucial at

U. M. Heller, F. Karsch, J. Rank

We discuss the calculation of electric and magnetic screening masses in SU(2) gauge theory. The temperature dependence of these masses obtained from the long-distance behaviour of spatial correlation functions has been analyzed for temperatures up to 10000 T_c.

C. Adloff

A measurement is made of the cross section for the process ep --> eXY in deep-inelastic scattering with the H1 detector at HERA. The cross section is presented in terms of a differential structure function F_2^D(3)(x_P,beta,Q^2) of the proton over the kinematic range 4.5 < Q^2 < 75 GeV^2. The dependence of F_2^D(3) on x_P is found to vary with beta, demonstr

SLD Collaboration

We report a new measurement of Rb = Gamma(Z0->b-bbar) / Gamma(Z0->hadrons) using a double tag technique, where the b hemisphere selection is based on the reconstructed mass of the B hadron decay vertex. The measurement was performed using a sample of 130k hadronic Z0 events, collected with the SLD at the SLC. The method utilizes the 3-D vertexing abilities o

Dorje C. Brody, Lane P. Hughston

Classical and quantum statistical mechanics are cast here in the language of projective geometry to provide a unified geometrical framework for statistical physics. After reviewing the Hilbert space formulation of classical statistical thermodynamics, we introduce projective geometry as a basis for analysing probabilistic aspects of statistical physics. In p

M. A. Grebeniuk, V. D. Ivashchuk, V. N. Melnikov

Multidimensional cosmological model describing the evolution of one Einstein space of non-zero curvature and n Ricci-flat internal spaces is considered. The action contains several dilatonic scalar fields and antisymmetric forms. When forms are chosen to be proportional of volume forms of p-brane submanifolds of internal space manifold, the Toda-like Lagrang

Jarmo Makela, Pasi Repo

We consider a Hamiltonian quantum theory of spherically symmetric, asymptotically flat electrovacuum spacetimes. The physical phase space of such spacetimes is spanned by the mass and the charge parameters $M$ and $Q$ of the Reissner-Nordström black hole, together with the corresponding canonical momenta. In this four-dimensional phase space, we perform a ca

J. E. Sonier, R. F. Kiefl, J. H. Brewer, J. Chakhalian

Muon-spin rotation spectroscopy has been used to measure the internal magnetic field distribution in NbSe2 for Hc1 << H < 0.25 Hc2. The deduced profiles of the supercurrent density indicate that the vortex-core radius in the bulk decreases sharply with increasing magnetic field. This effect, which is attributed to increased vortex-vortex interactions, does n

J. E. Sonier, J. H. Brewer, R. F. Kiefl, D. A. Bonn

The internal field distribution in the vortex state of YBa2Cu3O6.60 is shown to be a sensitive measure of both the magnetic penetration depth and the vortex-core radius. The temperature dependence of the vortex core radius is found to be weaker than in the conventional superconductor NbSe2 and much weaker than theoretical predictions for an isolated vortex.

Marton Sasvari, Janos Kertesz

The jamming transition in the stochastic cellular automaton model (Nagel-Schreckenberg model) of highway traffic is analyzed in detail, by studying the relaxation time, a mapping to surface growth problems and the investigation of correlation functions. Three different classes of behavior can be distinguished depending on the speed limit $v_{max}$. For $v_{m

A. L. Burin, J. L. Birman, A. Bulatov, H. Rabitz

We propose a new method to obtain a squeezed matter field of atomic vibrations by use of an optical lattice, and the laser pulse technique of Garrett et al used for acoustic phonons [1]. We show that it is possible to reduce the variance of atomic momentum to a value as low as the recoil momentum. Consequently, cooling to recoil energy can be achieved.

Pierre Le Doussal, Kay Jörg Wiese

We study the dynamics of polymers and elastic manifolds in non potential static random flows. We find that barriers are generated from combined effects of elasticity, disorder and thermal fluctuations. This leads to glassy trapping even in pure barrier-free divergenceless flows $v {f \to 0}{\sim} f^ϕ$ ($ϕ> 1$). The physics is described by a new RG fixed poin

V. K. Kalatsky, V. L. Pokrovsky

We demonstrate that the system of localized magnetic moments in HoNi$_2$B$_2$C can be described by the 4-positional clock model. This model, at a proper choice of the coupling constants, yields several metamagnetic phases in magnetic field at zero temperature in full agreement with the experimental phase diagram. The model incorporates couplings between not

P. Ohberg, S. Stenholm

We present a numerical study of a trapped binary Bose-condensed gas by solving the corresponding Hartree-Fock equations. The density profile of the binary Bose gas is solved with a harmonic trapping potential as a function of temperature in two and three dimensions. We find a symmetry breaking in the two dimensional case where the two condensates separate. W

Alex Kamenev, Yuval Gefen

We consider a multiple tunneling process into a quantum dot capacitively coupled to a dissipative environment. The problem is mapped onto an anisotropic Kondo model in its Coulomb gas representation. The tunneling barrier resistance and the dissipative resistance of the environment correspond to the transverse and the longitudinal Kondo couplings respectivel

Peter Ashwin, A. M. Rucklidge

We examine a model system where attractors may consist of a heteroclinic cycle between chaotic sets; this `cycling chaos&#39; manifests itself as trajectories that spend increasingly long periods lingering near chaotic invariant sets interspersed with short transitions between neighbourhoods of these sets. This behaviour can be robust (i.e., structurally sta

B. J. Wallace, T. L. Landecker, A. R. Taylor

A multi-wavelength investigation of the candidate supernova remnant G63.7+1.1 and its surrounding interstellar medium is presented. On the basis of radio continuum data we conclude that the object is a filled-center supernova remnant, perhaps in the course of becoming a composite remnant. The morphology of the remnant, along with HI, 12CO and high resolution

Frazer N. Owen, Michael J. Ledlow, Glenn E. Morrison, John M. Hill

We report optical imaging and spectroscopy of 41 galaxies in a 22 arcmin square region surrounding Cygnus A. The results show that there is an extensive rich cluster associated with Cygnus A of Abell richness at least 1 and possibly as high as 4. The velocity histogram has two peaks, one centered on Cygnus A, and a more significant peak redshifted by about 2

M. R. Garcia, J. E. McClintock, R. Narayan, P. J. Callanan

Recently, Narayan, Garcia and McClintock showed that there is a difference in the quiescent luminosities of black hole and neutron star x-ray nova: when the quiescent, Eddington scaled luminosities are compared, every black hole x-ray nova (BHXN) is fainter than every the neutron star x-ray nova (NSXN). To this earlier work we add three more BHXN, GRO J1655-

E. Vazquez-Semadeni, J. Canto, S. Lizano

We present numerical simulations of an isothermal turbulent gas undergoing gravitational collapse, aimed at testing for ``logatropic&#39;&#39; behavior of the form $P_t \sim \log ρ$, where $P_t$ is the ``turbulent pressure&#39;&#39; and $ρ$ is the density. To this end, we monitor the evolution of the turbulent velocity dispersion $σ$ as the density increases

P. J. Armitage, J. E. Pringle

We examine the consequences of radiatively driven warping of accretion disks surrounding pre-main-sequence stars. These disks are stable against warping if the luminosity arises from a steady accretion flow, but are unstable at late times when the intrinsic luminosity of the star overwhelms that provided by the disk. Warps can be excited for stars with lumin

T. K. Gaisser, Todor Stanev

We present the distribution of the production heights of atmsopheric neutrinos as a function of zenith angle and neutrino energy. The distributions can be used as the input for evaluation of neutrino propagation under various hypotheses for neutrino flavor oscillations.

D. J. Burke, C. A. Collins, R. M. Sharples, A. K. Romer

We present the z = 0.3 - 0.7 cluster X-ray luminosity function (XLF) determined from the Southern SHARC (Serendipitous High-redshift Archival ROSAT Cluster) survey. Over the luminosity range L ~ (0.3 - 3) x 10^44 erg/s (0.5 - 2.0 keV) the XLF is in close agreement with that of the low redshift X-ray cluster population. This result greatly strengthens our pre

D. Raboud, J. -C. Mermilliod

On the basis of the best available member list and duplicity information, we have studied the radial distribution of 270 stars and multiple systems earlier than K0 in the Pleiades. Five new long period spectroscopic binaries have been identified from the CORAVEL observations. We have found a clear mass segregation between binaries and single stars, which is

Peter Schneider, Ludovic van Waerbeke, Bhuvnesh Jain, Guido Kruse

We consider here a new statistical measure for cosmic shear, the aperture mass Map, which is defined as a spatially filtered projected density field and which can be measured directly from the image distortions of high-redshift galaxies. By selecting an appropriate spatial filter function, the dispersion of the aperture mass is a convolution of the power spe

Mitchell C. Begelman

Jets and pulsar-fed supernova remnants (plerions) tend to develop highly organized toroidal magnetic field. Such a field structure could explain the polarization properties of some jets, and contribute to their lateral confinement. A toroidal field geometry is also central to models for the Crab Nebula - the archetypal plerion - and leads to the deduction th

Ziv Ran

Extending the method of Part I (alg-geom/9704004), we give recursive formulae for: the genus-1 Severi degree (formula first found by Getzler), the degree of the variety of 1-cuspidal curves of genus 0 or 1, and the linear (sectional) geometric genus of the genus-0 and genus-1 Severi varieties. The proof is short and elementary.

T. Droese, M. Batsch, I. Kh. Zharekeshev, B. Kramer

The phase diagram of localization is numerically calculated for a three-dimensional disordered system in the presence of a magnetic field using the Peierls substitution. The mobility edge trajectory shifts in the energy-disorder space when increasing the field. In the band center, localized states near the phase boundary become delocalized. The obtained fiel

Robert B. Griffiths

In consistent history quantum theory, a description of the time development of a quantum system requires choosing a framework or consistent family, and then calculating probabilities for the different histories which it contains. It is argued that the framework is chosen by the physicist constructing a description of a quantum system on the basis of question

R. Mikulla, P. Gumbsch, H. -R. Trebin

A dislocation moving through a quasicrystal is leaving in its wake a fault denoted phason wall. For a two-dimensional model quasicrystal the disregistry energy of this phason wall is studied to determine possible Burgers vectors of the quasicrystalline structure. Contrary to periodic crystals, the disregistry energy is an average quantity with large fluctuat

Sutapa Mukherji, Somendra M. Bhattacharjee

We propose a phenomenological equation to describe kinetic roughening of a growing surface in presence of long range interactions. The roughness of the evolving surface depends on the long range feature, and several distinct scenarios of phase transitions are possible. Experimental implications are discussed.

L. Canali, J. W. G. Wildoer, O. Kerkhof, L. P. Kouwenhoven

The properties of InAs (110) surfaces have been investigated by means of low-temperature scanning tunneling microscopy and spectroscopy. A technique for ex-situ sulphur passivation has been developed to form an accumulation layer on such a surface. Tunneling spectroscopy at 4.2 K shows the presence of 2D subbands in the accumulation layer. Measurements in hi

Harald Fritzsch

The observed inclusive decay of B-mesons into eta&#39; + X is interpreted as the consequence of the gluonic decay of the b-quark into an s-quark. As a result of the QCD anomaly this decay proceeds partly as the decay b ---> s + eta&#39;, similar to b ---> s + J/psi. The hadronic recoiling system is found to have a relatively large mass. Analogously one expec

Ian Smail, R. J. Ivison, A. W. Blain

We present the first results of a sub-millimeter survey of distant clusters using the new Sub-mm Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. We have mapped fields in two massive, concentrated clusters, A370 at z=0.37 and Cl2244-02 at z=0.33, at wavelengths of 450 and 850-um. The resulting continuum maps cover a total area of abo

R. Manvelyan, A. Melikyan, R. Mkrtchyan

We apply the light-cone hamiltonian approach to D2-brane, and derive the equivalent gauge-invariant Lagrangian. The later appears to be that of three-dimensional Yang-Mills theory, interacting with matter fields, in the special external induced metric, depending on matter fields. The duality between this theory and 11d membrane is shown.

Anand Raman, John Newman, Jon Patrick

This paper addresses the problem of deriving distance measures between parent and daughter languages with specific relevance to historical Chinese phonology. The diachronic relationship between the languages is modelled as a Probabilistic Finite State Automaton. The Minimum Message Length principle is then employed to find the complexity of this structure. T

J. Hietarinta

We give an elementary introduction to Hirota&#39;s direct method of constructing multisoliton solutions to integrable nonlinear evolution equations. We discuss in detail how this works for equations in the Korteweg-de Vries class. We also show how Hirota&#39;s method can be used to search for new integrable evolution equations by testing for the existence of

Q. P. Liu

A new Lax operator is proposed from the viewpoint of constructing the integrable hierarchies related with N=2 super $W_n$ algebra. It is shown that the Poisson algebra associated to the second Hamiltonian structure for the resulted hierarchy contains the N=2 super Virasoro algebra as a proper subalgebra. The simplest cases are discussed in detail. In particu

V. S. Gerdjikov, E. G. Evstatiev, D. J. Kaup, G. L. Diankov

Using the complex Toda chain (CTC) as a model for the propagation of the N-soliton pulse trains of the nonlinear Schrodinger (NLS) equation, we predict the asymptotic behavior of these trains. The following asymptotic regimes are stable: (i)~asymptotically free propagation of all N solitons; (ii)~bound state regime where the N solitons may move quasi-equidis

Georg Junker, John R. Klauder

The quantization of systems with first- and second-class constraints within the coherent-state path-integral approach is extended to quantum systems with fermionic degrees of freedom. As in the bosonic case the importance of path-integral measures for Lagrange multipliers, which in this case are in general expected to be elements of a Grassmann algebra, is e

Piotr M. Hajac

The relationship between the exactness of a first order differential calculus on a comodule algebra $P$ and the Galois property of $P$ is investigated.

Dinesh Kumar Srivastava, Klaus Geiger

We evaluate the spectra of produced particles (pions, kaons, antiprotons) from partonic cascades which may develop in the wake of heavy-ion collisions at CERN SPS energies and which may hadronize by formation of clusters which decay into hadrons. Using the experimental data obtained by NA35 and NA44 collaborations for S+S and Pb+Pb collisions, we conclude th

Attila Csoto, G. M. Hale

Resonances of certain light nuclei are explored by studying the complex pole structures of the scattering matrices. Among other results we predict the existence of three-neutron and three-proton resonances, a small spin-orbit splitting in the low-lying He-5 and Li-5 states and the nonexistence of the soft dipole resonance in He-6.

Csaba Csaki, Witold Skiba

We describe fivebrane configurations in M theory whose 4-d spacetime contains N=1 supersymmetric Sp or SO gauge fields and fundamentals of these groups. We show how field-theory dualities for Sp and SO groups can be derived using these fivebrane configurations in M theory.

Klaus Kirsten

In this letter we present the calculation of the $a_{5}$ heat kernel coefficient of the heat operator trace for a partial differential operator of Laplace type on a compact Riemannian manifold with Dirichlet and Robin boundary conditions.

Robert de Mello Koch, João P. Rodrigues

In this paper the dynamics of the classical chiral $QCD_{2}$ currents is studied. We describe how the dynamics of the theory can be summarized in an equation of the Lax form, thereby demonstrating the existence of an infinite set of conserved quantities. Next, the $r$ matrix of a fundamental Poisson relation is obtained and used to demonstrate that the conse

J. M. Hauser, W. Cassing, S. Leupold, M. H. Thoma

The hierarchy of equations of motion for equal-time Green functions in temporal gauge SU(N) Yang-Mills theory is truncated using an expansion in terms of connected Green functions. A second hierarchy of constraint equations arises from Gauss law and can be truncated in a similar way. Within this approximation scheme we investigate SU(2) Yang-Mills theory on

Larus Thorlacius

D-branes are string theory solitons defined by boundary conditions on open strings that end on them. They play an important role in the non-perturbative dynamics of string theory and have found a wide range of applications. These lectures give a basic introduction to D-branes and their dynamics.

M A Grigoriev, A M Semikhatov

In the triplectic quantization of general gauge theories, we prove a `triplectic&#39; analogue of the Darboux theorem: we show that the doublet of compatible antibrackets can be brought to a weakly-canonical form provided the general triplectic axioms of [BMS] are imposed together with some additional requirements that can be formulated in terms of marked fu

Nikolaos Kidonakis, George Sterman

We describe the resummation of singular distributions at partonic threshold in heavy quark production, generalizing results for Drell-Yan and other electroweak hard-scattering processes.

Rogerio Rosenfeld, Alfonso R. Zerwekh

We study in a model independent way the role of a techniomega resonance in the process e^+ e^- --> W^+ W^- Z at the Next Linear Collider.

R. S. Chivukula, F. M. Renard, C. Verzegnassi

In this paper we consider the information that can be obtained about a strongly-interacting symmetry breaking sector from precision measurements of four-fermion processes at LEP2 or a (500 GeV) NLC . Using a ``Z-peak&#39;&#39; subtracted approach to describe four-fermion processes, we show that measurements of the cross section for muon production, the relat

Arnd Brandenburg, Peter Uwer

We present in detail a calculation of the next-to-leading order QCD corrections to the process $e^+e^-\to 3$ jets with massive quarks. To isolate the soft and collinear divergencies of the four parton matrix elements, we modify the phase space slicing method to account for masses. Our computation allows for the prediction of oriented three jet events involvi

F. Maltoni, M. L. Mangano, A. Petrelli

We present the calculation of O(as^2 aem) corrections to heavy-quarkonium total photoproduction cross-sections. Results are given for the colour-octet component of S and P waves. The calculation is performed using covariant projectors in dimensional regularization. A phenomenological study of the results, including a discussion of the high-energy behaviour o

Mohammad R. Ahamdy, Emi Kou, Akio Sugamoto

We calculate the decay rate B-> X_s photon photon via intermediate psuedoscalar charmonium eta_c. This process is thought to be the main long-distance contribution which dominates the corresponding inclusive rare B decay. We point out that once the momentum dependence of eta_c-> photon photon conversion strength, due to off-shellness of the intermediate eta_