July 1997 arXiv papers — page 6

Konstantin Zyablyuk

The lagrangian of N=2, D=6 supergravity coupled to E_7 X SU(2) vector- and hyper-multiplets is derived. For this purpose the coset manifold E_8/E_7 X SU(2), parametrized by the scalars of the hypermultiplet, is constructed. A difference from the case of Sp(n)-matter is pointed out. This model can be considered as an intermediate step in the compactification

K. Kamimura, R. Kuriki

We present a candidate of anomaly and Wess Zumino action of the two dimensional supergravity coupling with matters in a super-Weyl invariant regularization. It is a generalization of the Weyl and the area preserving \Diff invariant formulation of two dimensional gravity theory.

P. S. Gill, Manmohan Gupta

Natural 4 zeros texture mass matrices recently proposed by Fritzsch and Xing have been investigated by including `non-leading'corrections in the context of latest data regarding m_t^{pole} and V_{CKM} matrix elements. Apart from accommodating m_t^{pole} in the range 175\pm15 GeV, |V_{cb}| and |V_{ub}/V_{cb}|=0.08\pm0.02, the analysis with maximal CP-viol

S. J. Brodsky, F. Hautmann, D. E. Soper

We discuss virtual photon scattering in the region dominated by BFKL exchange and report results for the cross sections at present and future e+ e- colliders.

John Ellis

Various aspects of physics at LEP 2 are reviewed from a phenomenological point of view. We first discuss the search for Higgs bosons, which might be relatively light if indications from the precision electroweak data and supersymmetry are correct. Then WW physics is discussed, with particular emphasis on the problems in measuring mW by the kinematic reconstr

Ann E. Nelson

I review the motivation for dynamical supersymmetry breaking, the various mechanisms which have been discovered, and the prospects for model building.

M. Diehl

I review some recent developments in the QCD description of elastic vector meson production, focusing on issues like the meson wave function, the gluon density in the proton, factorisation, the use of parton-hadron duality and the nonperturbative vacuum.

Gert Aarts

I discuss the possibility of using classical field theory to approximate hot, real-time quantum field theory. I calculate, in a scalar theory, the classical two point and four point function in perturbation theory. The counterterms needed to make the classical correlation functions finite are dictated by the superrenormalizability of the static theory. The c

E. Poppitz, S. P. Trivedi

We consider the idea of combining the supersymmetry breaking and messenger sectors in models of gauge-mediated supersymmetry breaking. We discuss the advantages and problems of such models, and present an existence proof by constructing an explicit example. We explore in some detail the low-energy supersymmetry-breaking dynamics and the generation of supersy

A. V. Sidorov, M. V. Tokarev

A detailed NNLO QCD analysis of new CCFR data on the $xF_3$ structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QCD analysis of the structure function were used to study the $Q^2-$dependence of the G

Deog Ki Hong

We derive the (Wilsonian) low energy effective Lagrangian for Quantum Electrodynamics under external constant magnetic field by integrating out all electrons except those in the lowest Landau level. We find the one-loop effective Lagrangian contains a marginal four-Fermi interaction with anomalous dimension, ${(\ln2)^2\over 2π^2}e^4$. Renormalization group a

Maxim Pospelov

In the world with axion the precise measurement of gravitational force and check of the equivalence principle at small distances, $λ\sim 1cm$ and less, could provide an additional test of CP symmetry. Using the chiral approach, we connect the strength of CP-odd axion-nucleon vertex with CP-odd pion-nucleon coupling for color electric dipole moments of quarks

J. Schwiening

The DIRC is a Cherenkov imaging detector based on total internal reflection for the BaBar detector at PEP-II. The principles of the DIRC ring imaging Cherenkov technique are explained and its choice for the BaBar detector particle identification system is motivated. The detector design and the status of the R&D are discussed. Results of the measurement of th

V. Melik-Alaverdian, N. E. Bonesteel, G. Ortiz

A generalized diffusion Monte Carlo method for solving the many-body Schrödinger equation on curved manifolds is introduced and used to perform a `fixed-phase' simulation of the fractional quantum Hall effect on the Haldane sphere. This new method is used to study the effect of Landau level mixing on the $ν=1/3$ energy gap and the relative stability of s

Kyungsun Moon, Kieran Mullen

Starting with a Chern-Simons theory, we derive an effective action for interacting quantum Hall skyrmions that takes into account both large-distance physics and short-distance details as well. We numerically calculate the classical static skyrmion profile from this action and find excellent agreement with other, microscopic calculations over a wide range of

Boris V. Fine

A new approach is presented that treats NMR spin-spin relaxation as kinetics in spin phase space. The approach is applied to free induction decay (FID) in solids containing equivalent nuclear spins 1/2. The description obtained does not involve adjustable parameters. As an example, the calculation is performed for the fluorine FID in calcium fluoride, and th

Gilson Carneiro

Vortex-line equilibrium configurations and critical currents for type-II superconducting films at zero-temperature are studied theoretically. The films are assumed to be of thickness less than or equal to the penetration depth, free of pinning by imperfections, and to be subjected to a magnetic field parallel to the film surfaces and to a transport current p

Martin Rost, Joachim Krug

The conserved Sine-Gordon Equation with nonconserved shot noise is used to model homoepitaxial crystal growth. With increasing coverage the renormalized pinning potential changes from strong to weak. This is interpreted as a transition from layer-by-layer to rough growth. The associated length and time scales are identified, and found to agree with recent sc

J. Kastrup, R. Hey, K. H. Ploog, H. T. Grahn

Tunable oscillatory modes of electric-field domains in doped semiconductor superlattices are reported. The experimental investigations demonstrate the realization of tunable, GHz frequencies in GaAs-AlAs superlattices covering the temperature region from 5 to 300 K. The orgin of the tunable oscillatory modes is determined using an analytical and a numerical

A. Wacker, M. Moscoso, M. Kindelan, L. L. Bonilla

We review the occurrence of electric-field domains in doped superlattices within a discrete drift model. A complete analysis of the construction and stability of stationary field profiles having two domains is carried out. As a consequence, we can provide a simple analytical estimation for the doping density above which stable stable domains occur. This boun

J. F. F. Mendes, M. A. Santos

Short time Monte Carlo methods are used to study the nonequilibrium ferromagnetic phase transition in a majority vote model in two dimensions. The existance of an initial critical slip regime is verified. The measured values of dyamic exponents $z=2.170(5)$ and $θ= 0.191(2)$ are in excellent agreement with those of the kinetic Ising model universality class.

Martin Fuchs, Michel Bockstedte, Eckhard Pehlke, Matthias Scheffler

In ab initio pseudopotential calculations within density-functional theory the nonlinear exchange-correlation interaction between valence and core electrons is often treated linearly through the pseudopotential. We discuss the accuracy and limitations of this approximation regarding a comparison of the local density approximation (LDA) and generalized gradie

R. Combescot

We propose an extension to other high T_{c } compounds of a model introduced earlier for YBCO. In the ''self-doped'' compounds we assume that the doping part (namely the BiO, HgO, TlO planes in BSCCO, HBCCO, TBCCO respectively) is metallic, which leads to a multiband model. This assumption is supported by band structure calculations. Taking a

P. Haronska, J. Wilder, T. A. Vilgis

This paper discusses the elastic behavior of a single polyelectrolyte chain. A simple scaling analysis as in self avoiding walk chains are not possible, because three interplaying relevant length scales are involved, i.e., the Debye screening length and the Pincus blob size. Therefore a selfconsistent computation of an effective variational propagator is emp

P. Simon

We investigate the effect of weak disorder on different coupled $q$-state Potts models with $q\le 4$ using two loops renormalisation group. This study presents new examples of first order transitions driven by randomness. We found that weak disorder makes the models decouple. Therefore, it appears that no relations emerge, at a perturbation level, between th

Gongwen Peng, Takao Ohta

On the basis of physical considerations we propose a one-dimensional discrete lattice model for the density relaxation of granular materials under tapping. Solving the difference equation numerically, we find a logarithmic time-dependence of the density relaxation. This is in agreement with experimental results of Knight et al. [Phys. Rev. E 51, 3957(1995)].

José-Luis Mozos, C. C. Wan, Gianni Taraschi, Jian Wang

When a single atom is sandwiched in between two electrodes, an atomic tunneling device may be realized depending on the distance between the atom and the electrodes. We have performed first-principles pesudopotential calculation in conjunction with a three-dimensional evaluation of the quantum scattering matrix for such a device. We predict the quantum condu

Mi-Ae Park, M. H. Lee, Yong-Jihn Kim

The influence of (non-magnetic and magnetic) impurities on the transition temperature of a d-wave superconductor is studied anew within the framework of BCS theory. Pairing interaction decreases linearly with the impurity concentration. Accordingly $T_{c}$ suppression is proportional to the (potential or exchange) scattering rate, $1/τ$, due to impurities. T

Thorsten Brants, Wojciech Skut, Brigitte Krenn

This paper addresses issues in automated treebank construction. We show how standard part-of-speech tagging techniques extend to the more general problem of structural annotation, especially for determining grammatical functions and syntactic categories. Annotation is viewed as an interactive process where manual and automatic processing alternate. Efficienc

Sang-Yoon Kim, S. H. Shin, J. Yi, J. W. Jang

An experimental study of bifurcations associated with stability of stationary points (SP's) in a parametrically forced magnetic pendulum and a comparison of its results with numerical results are presented. The critical values for which the SP's lose or gain their stability are experimentally measured by varying the two parameters $Ω$ (the normalized

D. Munshi, L. Y. Chiang, P. Coles, A. L. Melott

Using an ensemble of high resolution 2D numerical simulations, we explore the scaling properties of cosmological density fluctuations in the non-linear regime. We study the scaling behaviour of the usual $N$--point volume-averaged correlations, and also examine the scaling of the entire probability density function (pdf) of the fluctuations. We focus on two

Carlos A. O. Torres, Germano R. Quast, Roger Coziol, Francisco Jablonski

In the course of the Pico dos Dias survey (PDS), we identified the stellar like object PDS456 at coordinates alpha = 17h 28m 19.796s, delta = -14deg 15' 55.87'' (epoch 2000), with a relatively nearby (z = 0.184) and bright (B = 14.69) quasar. Its position at Galactic coordinates l_II = 10.4deg, b_II = +11.2deg, near the bulge of the Galaxy, may e

Hiroshi Yukawa, Henri M. J. Boffin, Takuya Matsuda

We have performed three-dimensional numerical simulations of accretion discs in a close binary system using the Smoothed Particle Hydrodynamics method. Our result show that, contrary to previous claims, 3D discs do exist even when the specific heat ratio of the gas is as large as gamma=1.2. Although the disc is clearly more spread in the z-direction in this

D. H. Hughes, J. S. Dunlop

This paper describes a key submillimetre survey which we are currently conducting to address some of the outstanding questions in cosmology - how, at what epoch and over what period of time did massive galaxies form at high redshift? A summary of the technical feasibility of future submillimetre observations with new ground-based, airborne and satellite tele

A. G. Michalitsianos, E. E. Falco, J. A. Munoz, P. Hintzen

We obtained MMT spectra of the gravitational lens candidate UM425 to compare the redshifts and line profile structures of lens components A and B, which are separated by ~6.5". The CIV lambda 1550 A emission in both A and B exhibits Broad Absorption Line (BAL) structure, consistent with the earlier detection of BAL structure in OVI lambda 1033 A and NV l

M. A. C. Perryman, A. G. A. Brown, Y. Lebreton, A. Gomez

We use absolute trigonometric parallaxes from the Hipparcos Catalogue to determine individual distances to members of the Hyades cluster, from which the 3-dimensional structure of the cluster can be derived. Inertially-referenced proper motions are used to rediscuss distance determinations based on convergent-point analyses. A combination of parallaxes and p

H. C. Rosu, J. L. Romero

For the one-dimensional Helmholtz equation we write the corresponding time-dependent Helmholtz Hamiltonian in order to study it as an Ermakov problem and derive geometrical angles and phases in this context

Pavel Etingof, Travis Schedler, Alexandre Soloviev

Recently V.Drinfeld formulated a number of problems in quantum group theory. In particular, he suggested to consider ``set-theoretical'' solutions of the quantum Yang-Baxter equation, i.e. solutions given by a permutation $R$ of the set $X\times X$, where $X$ is a fixed finite set. In this note we study such solutions, which satisfy the unitarity and

D. Fliegner, P. Haberl, M. G. Schmidt, C. Schubert

We apply the string inspired worldline formalism to the calculation of the higher derivative expansion of one-loop effective actions in non-Abelian gauge theory. For this purpose, we have completely computerized the method, using the symbolic manipulation programs FORM, PERL and M. Explicit results are given to sixth order in the inverse mass expansion, redu

Leonid P. Pryadko, Karen Chaltikian

We construct a generalization of the Chalker-Coddington network model to the case of fractional quantum Hall effect, which describes the tunneling between multiple chiral edges. We derive exact local and global duality symmetries of this model, and show that its infrared properties are identical to those of disordered planar Josephson junction array (JJA) in

M. M. Fogler, A. Yu. Dobin, B. I. Shklovskii

The resistivity minima of the quantum Hall effect arise due to the localization of the electron states at the Fermi energy, when it is positioned between adjacent Landau levels. In this paper we calculate the localization length $ξ$ of such states at even filling factors $ν= 2 N$. The calculation is done for several models of disorder (``white-noise,'&#3

K. Farakos, N. E. Mavromatos

We discuss dynamical breaking of non-abelian gauge groups in three dimensional (lattice) gauge systems via the formation of fermion condensates. A physically relevant example, motivated by condensed-matter physics, is that of a fermionic gauge theory with group $SU(2)\otimes U_S(1) \otimes U_{E}(1)$. In the strong U_S(1) region, the SU(2) symmetry breaks dow

K. Krisciunas

Over two dozen early F-type variable stars have been identified which constitute a new class of pulsating stars. These stars typically have periods between 0.5 and 3 days with V-band variability of several hundredths of a magnitude. Given the time scale of the variability, the pulsations would have to be non-radial gravity-mode pulsations. The pulsational na

Ivan K. Babenko, Mikhail G. Katz, Alexander I. Suciu

Let X be a closed manifold of dimension 2m >= 6 with torsion-free middle-dimensional homology. We construct metrics on X of arbitrarily small volume, such that every middle-dimensional submanifold of less than unit volume necessarily bounds. Thus, Loewner's theorem has no higher-dimensional analogue.

D. Birmingham, I. Sachs, S. Sen

The exact decay rate for emission of massless minimally coupled scalar fields by a non-extremal black hole in 2+1 dimensions is obtained. At low energy, the decay rate into scalars with zero angular momentum is correctly reproduced within conformal field theory. The conformal field theory has both left- and right-moving sectors and their contribution to the

V. Antonelli, E. Torrente Lujan

We solve a radial Schrödinger equation for the case of a multichannel square well plus an exponential potential in one of the channels. The solution is obtained by summing exactly the infinite terms of the perturbative series for the evolution operator of the system. Analytical expressions for the scattering matrix and the scattering length are given, a Dese

Otto C. W. Kong, Feng-Li Lin

We discuss the feasibility of spontaneous CP violation being induced by radiative corrections in 2HDM's, emphasizing on a consistent treatment at 1-loop level. Specifically, we analyze the cases of gaugino/higgsino effect on MSSM, and a new model proposed here with an extra, exotic, quark doublet. The latter model is phenomenologically interesting. One c

Hitoshi Yamamoto

We estimate the sensitivity of single lepton CP violation measurements with respect to that of traditional di-lepton measurements. We find that the sensitivity of the single lepton method is better than that of the di-lepton method. The achievable sensitivity with the currently available data is already in the range relevant to standard model predictions. We

M. Quandt, H. Reinhardt

We present a reformulation of SU(2) Yang-Mills theory in the maximal Abelian gauge, where the non-Abelian gauge field components are exactly integrated out at the expense of a new Abelian tensor field. The latter can be treated in a semiclassical approximation and the corresponding saddle point equation is derived. Besides the non-trivial solutions, which ar

N. Armesto, M. A. Braun, A. Capella, C. Pajares

The absorptive corrections resulting from the rescattering of a heavy flavour (the so-called nuclear absorption) are usually calculated with a probabilistic formula valid only in the low energy limit. We extend this formula to all energies using a quantum field theoretical approach. For charmonium and bottonium we find that the absorptive corrections in the

Bertrand Monthubert

We build a longitudinally smooth differentiable groupoid associated to any manifold with corners. The pseudodifferential calculus on this groupoid coincides with the pseudodifferential calculus of Melrose (also called b-calculus). We also define an algebra of rapidly decreasing functions on this groupoid; it contains the kernels of the smoothing operators of

Gia Dvali, Alexander Kusenko, Mikhail Shaposhnikov

Future experiments may discover new scalar particles with global charges and couplings that allow for solitonic states. If the effective potential has flat directions, the scalar VEV inside a large Q-ball can exceed the particle mass by many orders of magnitude. Models with low-energy supersymmetry breaking generically have both the scalars carrying some glo

Benjamin P. Lee, Andrew D. Rutenberg

We calculate the exact autocorrelation exponent lambda and persistence exponent theta, and also amplitudes, in the dilute limit of phase ordering for dimensions d >= 2. In the Lifshitz-Slyozov-Wagner limit of conserved order parameter dynamics we find theta = gamma_d*epsilon, a universal constant times the volume fraction. For autocorrelations, lambda = d at

W. Tittel, J. Brendel, B. Gisin, T. Herzog

Energy and time entangled photons at a wavelength of 1310 nm are produced by parametric downconversion in a KNbO3 crystal and are sent into all-fiber interferometers using a telecom fiber network. The two interferometers of this Franson-type test of the Bell-inequality are located 10.9 km apart from one another. Two-photon fringe visibilities of up to 81.6 %

Vladan Celebonovic

Starting from the recently derived expression for the chemical potential of the electron gas on a 1D lattice,and a well known thermodynamical relation,we have derived the equation of state and the specific heat of the electron gas on a 1D lattice.

Roberto Zucchini

We show that 4--dimensional conformal field theory is most naturally formulated on Kulkarni 4--folds, i. e. real 4--folds endowed with an integrable quaternionic structure. This leads to a formalism that parallels very closely that of 2--dimensional conformal field theory on Riemann surfaces. In this framework, the notion of Fueter analyticity, the quaternio

Michael Krämer

I discuss the production of leptoquarks in $p\bar{p}$ collisions at the Fermilab Tevatron. Evaluated on the basis of a recent next-to-leading order calculation, the combined D0 and CDF leptoquark searches lead to a parameter-free lower mass bound of about $\ms \simgt 240$ GeV for scalar leptoquarks or squarks decaying solely to a first generation charged lep

P. I. Porfyriadis, D. Papadopoulos

The null string's equations of motion and constraints in the Kerr spacetime are given. We assume a generic ansatz for the null strings in the Kerr spacetime and we present the resulting solutions in quadratures. Some specific string configurations, that follow from the generic one, are considered separately. In each case we also extract the corresponding

C. G. Tinney, X. Delfosse, T. Forveille

We present optical spectroscopy of three brown dwarf candidates identified in the first 1% of the DENIS sky survey. Low resolution spectra from 6430 - 9150A show these objects to have similar spectra to the brown dwarf candidate GD 165B. High resolution spectroscopy shows that one of the objects -- DENIS-P J1228.2-1547 -- has a strong 2.3+-0.05A equivalent w

Michael Dine

After briefly reviewing some arguments in favor of high scale and low scale supersymmetry breaking, I discuss a possible solution of the $μ$-problem of gauge mediated models.

Maciej Lewenstein, Anna Sanpera

We provide a constructive algorithm to find the best separable approximation to an arbitrary density matrix of a composite quantum system of finite dimensions. The method leads to a condition of separability and to a measure of entanglement.

H. Attias, Y. Alhassid

We present an approximation scheme for calculating observables and strength functions of finite fermionic systems at finite temperature such as hot nuclei. The approach is formulated within the framework of the Hubbard-Stratonovich transformation and goes beyond the static path approximation and the RPA by taking into account small amplitude time-dependent f

H. Heiselberg, A. P. Vischer

We discuss the complex phase generated in three pion correlation functions. The lowest order contribution to the phase is of order $q^2 R/K$, where $q$ is a typical relative momentum, $K$ is a typical center of mass momentum and $R$ is a typical radius parameter. This contribution is of purely kinematic origin. At next order we find a generic contribution of

M. Dasgupta, D. J. Hinde, J. R. Leigh, K. Hagino

The recent availability of precisely measured fusion cross-sections has enabled the extraction of a representation of the distribution of barriers encountered during fusion. These representations, obtained from a variety of reactions, provide a direct observation of how the structure of the fusing nuclei changes the inter-nuclear potential landscape, thus af

Alfredo T. Suzuki, Alexandre G. M. Schmidt

Feynman diagrams are the best tool we have to study perturbative quantum field theory. For this very reason the development of any new technique which allows us to compute Feynman integrals is welcome. By the middle of the 80's, Halliday and Ricotta suggested the possibility of using negative dimensional integrals to tackle the problem. The aim of this w

B. S. Acharya

We consider Type II string theories on ${\bf T^n}/{{\bf Z_2}^m}$ Joyce orbifolds. This class contains orbifolds which can be desingularised to give manifolds of $G_2$ $({\bf n}$$=$$7)$ and $Spin(7)$ holonomy $({\bf n}$$=$$8)$. In the $G_2$ holonomy case we present two types of $T$-duality transformation which are clearly generalisations of the $T$-duality/mi

P. S. Howe

It is shown that the equations of motion of eleven-dimensional supergravity follow from setting the dimension zero components of the superspace torsion tensor equal to the Dirac matrices. The proof of this assertion is facilitated by the introduction of a connection taking its values in the Lie algebra of $Spin(1,10)\times R^+$.

H. Lu, J. Maharana, S. Mukherji, C. N. Pope

The low energy effective actions which arise from string theory or M-theory are considered in the cosmological context, where the graviton, dilaton and antisymmetric tensor field strengths depend only on time. We show that previous results can be extended to include cosmological solutions that are related to the E_N Toda equations. The solutions of the Wheel

Fernando Quevedo

The different aspects of superstring phenomenology before and after 1995 are briefly reviewed. (Contribution to the conference SUSY97)

A. Krause, T. Plehn, M. Spira, P. M. Zerwas

The search for charged Higgs bosons, which are predicted in supersymmetric theories, is difficult at hadron colliders if the mass is large. In this paper we present the theoretical set-up for the production of charged Higgs boson pairs at the LHC in gluon-gluon collisions: $pp -> gg -> H^+ H^-$. When established experimentally, the trilinear couplings betwee

Alexander Kusenko, Gino Segre

We have recently proposed an explanation for the birth velocities of pulsars based on neutrino oscillations (hep-ph/9606428). One of the quantities, dN/dT, was evaluated in the approximation of constant chemical potential for the electrons. An alternative approximation based on the assumption Ye=const, used by Qian (astro-ph/9705055), yields a somewhat highe

Michael Rueter, H. G. Dosch

We determine the diffractive scattering amplitude of a color-dipole on a nucleon using a non-perturbative model of QCD which contains only parameters taken from low-energy physics. This allows to relate specific features of the confinement mechanisms with diffractive electro-production processes and structure functions. The agreement with phenomenological da

Tatsuo Kobayashi, Jisuke Kubo, Myriam Mondragon, George Zoupanos

Requiring the soft supersymmetry-breaking (SSB) parameters in finite gauge-Yukawa unified models to be finite up to and including two-loop order, we derive a two-loop sum rule for the soft scalar-masses. It is shown that this sum rule coincides with that of a certain class of string models in which the massive string states are organized into N=4 supermultip

A. Bashir, A. Kizilersu, M. R. Pennington

Dong, Munczek and Roberts have shown how the full 3-point vertex that appears in the Schwinger-Dyson equation for the fermion propagator can be expressed in terms of a constrained function $W_1$ in massless quenched QED. However, this analysis involved two key assumptions: that the fermion anomalous dimension vanishes in the Landau gauge and that the transve

J. Blümlein, J. Huston, C. Royon, R. Yoshida

A summary is given on the main aspects which were discussed by the working group. They include new results on the deep inelastic scattering structure functions $F_2, xF_3, F_L$ and $F_2^{c\bar{c}}$ and their parametrizations, the measurement of the gluon density, recent theoretical work on the small $x$ behavior of structure functions, theoretical and experi

A. D. Dolgov

A review of the basic principles of baryogenesis is given. Baryogenesis in heavy particle decays as well as electroweak, SUSY-condensate, and spontaneous baryogenesis are discussed. The models of abundant creation of antimatter in the universe are briefly reviewed.

N. I. Kochelev

The contribution of the anomalous quark-gluon interaction induced by instantons to the polarized and unpolarized gluon distributions in nucleon is estimated. It is shown that this interaction leads to negative gluon polarization in nucleon.

Katsuji Yamamoto

Some aspects are considered on the flavor-nonconservation and $ CP $-violation arising from the quark mixings with singlet quarks. In certain models incorporating the singlet quarks, the contributions of the quark couplings to the neutral Higgs fields may become more significant than those of the neutral gauge interactions. Then, they would provide distinct

Nita Sinha, Rahul Sinha

We study the contributions of the CP violating anomalous WW-gamma interactions to b->s l^+ l^-. We obtain cutoff independent results on tilde kappa and tilde lambda, by constructing an asymmetry for the process B->K^*l^+l^-, where the B and B bar events are added. We show that a sample of 10^4 B-> K^*e^+e^- events, can yield a bound |tilde kappa| < 0.42 at 9

M. Laine

The construction and analysis of 3d effective theories for the description of the thermodynamics of the cosmological electroweak phase transition are reviewed. For the Standard Model and for the MSSM with stops somewhat heavier than the top, the effective theory is 3d SU(2)+Higgs, and the transition is strong enough for baryogenesis at no Higgs mass for the

S. Gardner, H. B. O&#39;Connell, A. W. Thomas

We study direct CP violation in $B^\pm \to ρ^\pmρ^0(ω) \to ρ^\pmπ^+π^-$ and focus specifically on the rate asymmetry in the $ρ^0$-$ω$ interference region. Here the strong phase is dominated by isospin violation, so that it can be essentially determined by $e^+e^- \to ρ^0 (ω) \to π^+π^-$ data. We find the CP-violating asymmetry to be of the order of 20% at th

Leslie S. Groer

We present results for various searches for signatures of standard and non-standard model Higgs boson decays conducted at the collider detectors CDF and DO using ~ 100 pb^-1 of integrated luminosity each from the Tevatron Collider Run 1 (1992-96) at \sqrt{s} = 1.8 TeV. No evidence for a Higgs boson decay is found and various limits are set.

G A Alekseev, J B Griffiths

Exact solutions of Einstein&#39;s vacuum equations are considered which describe gravitational waves with distinct wavefronts. A family of such solutions presented recently in which the wavefronts have various geometries and which propagate into a number of physically significant backgrounds is here related to an integral representation which is a generalisa

Winfried Zimdahl

The linear cosmological perturbation theory of an almost homogeneous and isotropic perfect fluid universe is reconsidered and formally simplified by introducing new covariant and gauge-invariant variables with physical interpretations on hypersurfaces of constant expansion, constant curvature or constant energy density. The existence of conserved perturbatio

L. Andersson, G. J. Galloway, R. Howard

The strong maximum principle is proved to hold for weak (in the sense of support functions) sub- and super-solutions to a class of quasi-linear elliptic equations that includes the mean curvature equation for $C^0$ spacelike hypersurfaces in a Lorentzian manifold. As one application a Lorentzian warped product splitting theorem is given.

R. Eder, W. Hanke, S. C. Zhang

In this work, we present numerical results which support SO(5) symmetry as a concept unifying superconductivity and antiferromagnetism in the high-temperature superconductors. Using exact cluster diagonalization, we verify the recently proposed SO(5) multiplet structures for a widely used microscopic model, the t-J model. Our results show that the d-wave sup

Bertrand Georgeot, Dima L. Shepelyansky

For many-body Fermi systems we determine the dependence of the Breit-Wigner width and inverse participation ratio (IPR) on interaction strength U > Uc and energy excitation dE > dE_ch when a crossover from Poisson to Wigner-Dyson P(s)-statistics takes place. At U > Uc the eigenstates are composed of a large number of noninteracting states and even for U < Uc

Ilya Ya. Goldsheid, Boris A. Khoruzhenko

We develop a theory which describes the behaviour of eigenvalues of a class of one-dimensional random non-Hermitian operators introduced recently by Hatano and Nelson. Under general assumptions on random parameters we prove that the eigenvalues are distributed along a curve in the complex plane. An equation for the curve is derived and the density of complex

D. A. Head, G. J. Rodgers

We introduce a theoretical model for the compaction of granular materials by discrete vibrations which is expected to hold when the intensity of vibration is low. The dynamical unit is taken to be clusters of granules that belong to the same collective structure. We rigourously construct the model from first principles and show that numerical solutions compa

R. B. Griffiths, H. J. Schellnhuber, H. Urbschat

The problem of finding the exact energies and configurations for the Frenkel-Kontorova model consisting of particles in one dimension connected to their nearest-neighbors by springs and placed in a periodic potential consisting of segments from parabolas of identical (positive) curvature but arbitrary height and spacing, is reduced to that of minimizing a ce

T. J. Newman, Michael R. Swift

We report on an extensive numerical investigation of the Kardar-Parisi-Zhang equation describing non-equilibrium interfaces. Attention is paid to the dependence of the growth exponents on the details of the distribution of the noise. All distributions considered are delta-correlated in space and time, and have finite cumulants. We find that the exponents bec

E. Otnes, A. Sudbø

We consider the Cooper-problem on a lattice model including onsite and near-neighbor interactions. Expanding the interaction in basis functions for the irreducible representation for the point group $C_{4v}$ yields a classification of the symmetry of the Cooper-pair wave function, which we calculate in real-space. A change of symmetry upon doping, from s-wav

Arkadi A. Odintsov, Yasuhiro Tokura, Seigo Tarucha

We investigate the transport of interacting electrons through single-mode quantum wires whose parameters are periodically modulated on the scale of the electronic Fermi wave length. The Umklapp and backscattering of electrons can be described in terms of non-uniform quantum sine-Gordon-like models which also incorporate the effects of electronic reservoirs (

Rajeev Agarwal

With the rapid explosion of the World Wide Web, it is becoming increasingly possible to easily acquire a wide variety of information such as flight schedules, yellow pages, used car prices, current stock prices, entertainment event schedules, account balances, etc. It would be very useful to have spoken dialogue interfaces for such information access tasks.

Uwe Moennich

To Rogers (1994) we owe the insight that monadic second order predicate logic with multiple successors (MSO) is well suited in many respects as a realistic formal base for syntactic theorizing. However, the agreeable formal properties of this logic come at a cost: MSO is equivalent with the class of regular tree automata/grammars, and, thereby, with the clas

Uwe Moennich

This note presents a method of interpreting the tree adjoining languages as the natural third step in a hierarchy that starts with the regular and the context-free languages. The central notion in this account is that of a higher-order substitution. Whereas in traditional presentations of rule systems for abstract language families the emphasis has been on a

Steven Bird

A lexical database tool tailored for phonological research is described. Database fields include transcriptions, glosses and hyperlinks to speech files. Database queries are expressed using HTML forms, and these permit regular expression search on any combination of fields. Regular expressions are passed directly to a Perl CGI program, enabling the full flex

P. Platania, M. Bensadoun, M. Bersanelli, G. De Amici

We present an analysis of simultaneous multifrequency measurements of the Galactic emission in the 1-10 GHz range with 18 degrees, angular resolution taken from a high altitude site. Our data yield a determination of the synchrotron spectral index between 1.4 GHz and 7.5 GHz of 2.81 +/- 0.16. Combining our data with the maps from Haslam et al. (1982) and Rei

Craig Sosin

We begin by presenting the analysis of a set of deep B- and V-band images of the central density cusp of the globular cluster M30 (NGC 7099), taken with the Faint Object Camera aboard the Hubble Space Telescope. These images are the first to resolve lower-mass main-sequence stars in the cluster&#39;s central 10&#39;&#39;. From the positions of individual sta

B. Boroson, W. P. Blair, A. F. Davidsen, S. D. Vrtilek

We have obtained a far-ultraviolet spectrum of the X-ray binary Hercules X-1/HZ Herculis using the Hopkins Ultraviolet Telescope aboard the Astro-1 space shuttle mission in 1990 December. This is the first spectrum of Her X-1 that extends down to the Lyman limit at 912 A. We observed emission lines of O VI, N V, and C IV, and the far UV continuum extending t