February 1996 arXiv papers — page 4

Hiroshi Toki, Shoichi Sasaki, Hiroko Ichie, Hideo Suganuma

Confinement and chiral symmetry breaking are the most fundamental phenomena in Quark Nuclear Physics, where hadrons and nuclei are described in terms of quarks and gluons. The dual Ginzburg-Landau (DGL) theory, which contains monopole fields as the most essential degrees of freedom and their condensation in the vacuum, is modeled to describe quark confinemen

H. Leutwyler

The paper collects the various pieces of information concerning the relative size of m_u, m_d and m_s. A coherent picture results, which constrains the mass ratios to a rather narrow range: m_u/m_d = 0.553 \pm 0.043, m_s/m_d = 18.9 \pm 0.8.

Christopher D. Carone, Lawrence J. Hall, Hitoshi Murayama

We construct a renormalizable, supersymmetric theory of flavor and $R$ parity based on the discrete flavor group $(S_3)^3$. The model can account for all the masses and mixing angles of the Standard Model, while maintaining sufficient squark degeneracy to circumvent the supersymmetric flavor problem. By starting with a simpler set of flavor symmetry breaking

S. Corley, T. Jacobson

The ``screen mapping" introduced by Susskind to implement 't Hooft's holographic hypothesis is studied. For a single screen time, there are an infinite number of images of a black hole event horizon, almost all of which have smaller area on the screen than the horizon area. This is consistent with the focusing equation because of the existence of focal point

Takashi Okamura

To discuss the quantum to classical transition in quantum cosmology, we study the decoherence factor and the peak of the Wigner function, which respectively represent the degree of decoherence and the degree to which the classical motion of the Universe is defined, in a Robertson-Walker universe model coupled with a scalar field. It is known that the decoher

Vipul Periwal

The Navier-Stokes equation describes the deterministic evolution of incompressible fluids. The effects of random initial conditions on solutions of this equation are studied. It is shown that there is an infrared stable fixed point accessible within the epsilon expansion, about $d_c=4,$ with a particular choice of viscosity. The behaviour of the usual viscou

Antonio M. R. Cadilhe, Vladimir Privman

We introduce a model with conserved dynamics, where nearest neighbor pairs of spins $\uparrow \downarrow (\downarrow \uparrow)$ can exchange to assume the configuration $\downarrow \uparrow (\uparrow \downarrow)$, with rate $β(α)$, through energy decreasing moves only. We report exact solution for the case when one of the rates, $α$ or $β$, is zero. The irre

K. W. Kehr, T. Wichmann

A survey is given on asymptotic diffusion coefficients of particles in lattices with random transition rates. Exact and approximate results for single particles are reviewed. A recent exact expression in $d = 1$ which includes occupation factors is discussed. The utilization of the result is demonstrated for the Miller-Abrahams model and a model of random ba

Hiroshi Imamura, Peter A. Makstym, Hideo Aoki

Exact diagonalization is used to study the quantum states of vertically coupled quantum dots in strong magnetic fields. We find a new sequence of angular momentum magic numbers which are a consequence of the electron correlation in the double dot. The new sequence occurs at low angular momenta and changes into the single dot sequence at a critical angular mo

Francesco Mezzadri, Antonio Scotti

In this paper we show that the quantum theory of chaos, based on the statistical theory of energy spectra, presents inconsistencies difficult to overcome. In classical mechanics a system described by an hamiltonian $H = H_1 + H_2$ (decomposable) cannot be ergodic, because there are always two dependent integrals of motion besides the constant of energy. In q

J. G. Cohen, D. W. Hogg, M. A. Pahre, R. Blandford

We present initial results from a redshift survey carried out with the Low Resolution Imaging Spectrograph on the 10~m W. M. Keck Telescope of a field 14.6 arc-min$^2$ in solid angle. In the redshift distribution of the 106 extragalactic objects in this sample we find five strong peaks, with velocity dispersions of ${\sim}500${\kms}. There is evidence for a

M. J. Page, F. J. Carrera, G. Hasinger, K. O. Mason

A sample of 198 soft X--ray selected active galactic nuclei (AGN) from the ROSAT International X--ray Optical Survey (RIXOS), is used to investigate the X--ray luminosity function and its evolution. RIXOS, with a flux limit of 3E-14 erg s-1 cm-2 (0.5 to 2.0 keV), samples a broad range in redshift over 20 deg^2 of sky, and is almost completely identified; it

Y. I. Byun, C. J. Grillmair, S. M. Faber, E. A. Ajhar

We present a set of structural parameters for the central parts of 57 early-type galaxies observed with the Planetary Camera of the Hubble Space Telescope. These parameters are based on a new empirical law that successfully characterizes the centers of early type galaxies. This empirical law assumes that the surface brightness profile is a combination of two

Pedro Avelino, Robert Caldwell

We examine variations in the equation of state of the cosmic string portion of the cosmological fluid which lead to perturbations of the background matter density. These fluctuations in the equation of state are due to variations in the local density of cosmic string loops and gravitational radiation. Constructing a crude model of the distribution of entropy

M. Pohl

The lineless power-law emission observed by ASCA from the northeastern rim of the supernova remnant SN1006 has recently been interpreted as synchrotron radiation of electrons with energies around 100 TeV. In this letter we calculate the flux of inverse Compton emission at TeV photon energies that is a natural consequence of the existence of such high energy

Claude Chevalier, Sergio A. Ilovaisky

CCD photometry of the black hole candidate GRO~J0422+32 in quiescence, obtained at Haute-Provence from 1994 November to 1995 February, reveals a double-wave modulation at a period close to the value we found during outbursts and also close to one of the possible periods derived by Filippenko, Matheson and Ho (1995) from spectroscopic observations with the W.

A. Mücke, M. Pohl, P. Reich, W. Reich

The possibility of a correlation between the radio (cm)- and $γ$-ray luminosity of variable AGN seen by EGRET is investigated. We performed Monte-Carlo simulations of typical data sets and applied different correlation techniques (partial correlation analysis, $χ^2$-test applied on flux-flux relations) in view of a truncation bias caused by sensitivity limit

Ravi K. Sheth

The Press--Schechter description of gravitational clustering from an initially Poisson distribution is shown to be equivalent to the well studied Galton--Watson branching process. This correspondence is used to provide a detailed description of the evolution of hierarchical clustering, including a complete description of the merger history tree. The relation

Ingo Hadan

Motivated by questions occuring in the construction of certain twistor spaces the parameter space of conics tangent to a given quartic is investigated. For a given real quartic surface in complex $\PP ^3$ that has exactly 13 ordinary nodes as singularities this parameter space is studied. In particular, its irreducible components are described.

V. D. Efros, W. Balogh, H. Herndl, R. Hofinger

Recent investigations suggest that the neutrino--heated hot bubble between the nascent neutron star and the overlying stellar mantle of a type--II supernova may be the site of the r--process. In the preceding $α$--process building up the elements to $A \approx 100$, the $^4$He(2n,$γ$)$^6$He-- and $^6$He($α$,n)$^9$Be--reactions bridging the instability gap at

Ori J. Ganor, Amihay Hanany

T-duality is used to extract information on an instanton of zero size in the $E_8\times E_8$ heterotic string. We discuss the possibility of the appearance of a tensionless anti-self-dual non-critical string through an implementation of the mechanism suggested by Strominger of two coincident 5-branes. It is argued that when an instanton shrinks to zero size

Emmanuel Bertin, Michel Dennefeld

We present bright galaxy number counts in the blue (16<Bj<21) and red (15<R<19.5) passbands, performed over 145 sq. degrees, both in the northern and southern galactic hemispheres. The work was conducted on Schmidt plates digitized with the MAMA machine, and individually calibrated using an adequate number of CCD sequences. We find a relatively large density

S. Khoroshkin, D. Lebedev, S. Pakuliak

We continue the investigation of the central extended Yangian double [S. Khoroshkin, q-alg/9602031]. In this paper we study the intertwining operators for certain infinite dimensional representations of $\Yd$, which are deformed analogs of the highest weight representations of the affine algebra $\aff$ at level 1. We give bosonized expressions for intertwini

O. V. Teryaev, O. L. Veretin

Quark mass corrections to the spin partonic structure function g_1(x,Q^2) and function F_3(x,Q^2) are obtained at the order O(alpha_s) along with the coefficient functions C^{(A)} and C^{(V)} related to the Bjorken and Gross--Llewellyn-Smith sum rules. In the massless limit the difference between F_3 and g_1 is encountered to be (alpha_s/π)*CF*(1-x). The res

H. Grosse, C. Klimcik, P. Presnajder

The truncated 4-dimensional sphere $S^4$ and the action of the self-interacting scalar field on it are constructed. The path integral quantization is performed while simultaneously keeping the SO(5) symmetry and the finite number of degrees of freedom. The usual field theory UV-divergences are manifestly absent.

Frank Meier, Hans Walliser

We present a procedure to calculate 1-loop graphs in the soliton sector of chiral Lagrangians and use it to calculate quantum corrections to certain baryon observables in Skyrme-type models. Results generally show an improvement over the values obtained in tree approximation except for the case of the axial coupling g_A.

Minoru Takahashi, Hiroaki Nakamura, Subir Sachdev

We identify the critical theory controlling the universal, low temperature, macroscopic properties of both quantum and classical ferromagnetic chains. The theory is the quantum mechanics of a single rotor. The mapping leads to an efficient method for computing scaling functions to high accuracy.

David Beckman, Amalavoyal N. Chari, Srikrishna Devabhaktuni, John Preskill

We consider how to optimize memory use and computation time in operating a quantum computer. In particular, we estimate the number of memory qubits and the number of operations required to perform factorization, using the algorithm suggested by Shor. A $K$-bit number can be factored in time of order $K^3$ using a machine capable of storing $5K+1$ qubits. Eva

S. M. Khoroshkin

Central extension $\DYg$ of the Double of the Yangian is defined for a simple Lie algebra ${\bf g}$ with complete proof for ${\bf g} =sl_2$. Basic representations and intertwining operators are constructed for $\DY2$.

J. Schwieger, F. Šimkovic, Amand Faessler

We examine the violation of the Pauli exclusion principle in the Quasiparticle Random Phase Approximation (QRPA) calculation of the two-neutrino double beta decay matrix elements, which has its origin in the quasi-boson approximation. For that purpose we propose a new renormalized QRPA with proton-neutron pairing method (full-RQRPA) for nuclear structure stu

Achim Kempf

Studies in string theory and in quantum gravity suggest the existence of a finite lower bound to the possible resolution of lengths which, quantum theoretically, takes the form of a minimal uncertainty in positions $Δx_0$. A finite minimal uncertainty in momenta $Δp_0$ has been motivated from the absence of plane waves on generic curved spaces. Both effects

Paul S. Aspinwall, Mark Gross

A type IIA string compactified on a Calabi-Yau manifold which admits a K3 fibration is believed to be equivalent to a heterotic string in four dimensions. We study cases where a Calabi-Yau manifold can have more than one such fibration leading to equivalences between perturbatively inequivalent heterotic strings. This allows an analysis of an example in six

I. K. Kostov

The microscopic theories of quantum gravity related to integrable lattice models can be constructed as special deformations of pure gravity. Each such deformation is defined by a second order differential operator acting on the coupling constants. As a consequence, the theories with matter fields satisfy a set of constraints inherited from the integrable str

Jens B&#34;ockenhauer, J&#34;urgen Fuchs

We introduce a gauge group of internal symmetries of an ambient algebra as a new tool for investigating the superselection structure of WZW theories and the representation theory of the corresponding affine Lie algebras. The relevant ambient algebra arises from the description of these conformal field theories in terms of free fermions. As an illustration we

E. Elizalde, M. Lygren, D. V. Vassilevich

The Hodge--de Rham Laplacian on spheres acting on antisymmetric tensor fields is considered. Explicit expressions for the spectrum are derived in a quite direct way, confirming previous results. Associated functional determinants and the heat kernel expansion are evaluated. Using this method, new non--local counterterms in the quantum effective action are ob

B. L. Ioffe, I. A. Shushpanov

The structure functions of longitudinal virtual photon at low virtualities are calculated in the framework of chiral pertubation theory(ChPT) in the zero and first order of ChPT. It is assumed that the virtuality of target longitudinal photon is much less than the virtuality of the hard projectile photon and both are less than the characteristic ChPT scale.

J. Bartels, H. Lotter, M. Wuesthoff

We calculate the cross section for the production of two jets with large transverse momenta $\kf^2$ in DIS diffractive dissociation for both transverse and longitudinally polarized photons. The scale which defines the hardness of the pomeron is found to be $\kf^2\frac{Q^2+M^2}{M^2}$. We present analytic expressions and discuss numerical results relevant for

V. V. Kiselev

Using a quite accurate flavour-independence of $nS$-level mass differences in heavy quarkonia and a corresponding quasiclassical expression for the heavy quark binding energy, one shows that experimental data on masses of mesons with heavy quarks allow one to make the estimate $\bar Λ= 0.63\pm 0.03$ GeV.

V. V. Kiselev

In the framework of sum rules with a use of quarkonium mass spectrum, evaluated in the quasiclassical approximation, estimates of leptonic constant $f_B^{stat}\simeq 320\pm 60$ MeV in a static limit and for the average heavy quark momentum squared $μ_π^2 \simeq 0.5\pm 0.1$ GeV$^2$ are obtained.

S. Loh, T. S. Biro, U. Mosel, M. H. Thoma

A dynamical model of confinement based on a transport theoretical description of the Friedberg-Lee model is extended to explicit color degrees of freedom. The string tension is reproduced by an adiabatic string formation from the nucleon ground state. Color isovector oscillation modes of a $q\bar{q}$-system are investigated for a wide range of relative $q\ba

Jarkko Ahonen, Kari Enqvist

We solve numerically the Boltzmann equation in the early universe in the presence of a constant electric field and find the electrical conductivity $σ$ in the range $1\MeV\lsim T\lsim M_W$. The main contribution to $σ$ is shown to be due to leptonic interactions. For $T\lsim 100\MeV$ we find $σ\simeq 0.76T$ while at $T\simeq M_W$ we obtain $σ\simeq 6.7T$

R. K. Ellis, W. Vogelsang

A complete description of the calculation of anomalous dimensions (GLAP splitting functions) is given for parton distributions which appear in space-like processes. The calculation is performed in the light-cone gauge. The results are in agreement with the previous results of Furmanski and Petronzio.

Frank Cuypers

We discuss the leptoquark discovery potential of $e^-γ$ scattering and show how polarization and angular distributions can be used to differentiate the different types of leptoquarks.

R. Loll

We show that the Hamiltonian of four-dimensional Lorentzian gravity, defined on a space of real, SU(2)-valued connections, in spite of its non-polynomiality possesses a natural quantum analogue in a lattice-discretized formulation of the theory. This opens the way for a systematic investigation of its spectrum. The unambiguous and well-defined scalar product

M. O. Katanaev, W. Kummer, H. Liebl

The black hole of the widely used ordinary 2d--dilaton model (DBH) deviates from the Schwarzschild black hole (SBH) of General Relativity in one important feature: Whereas non-null extremals or geodesics show the expected incompleteness this turns out {\it not to be the case for the null extremals}. After a simple analysis in Kruskal coordinates for singular

Nandor Sieben

The recently developed theory of partial actions of discrete groups on $C^*$-algebras is extended. A related concept of actions of inverse semigroups on $C^*$-algebras is defined, including covariant representations and crossed products. The main result is that every partial crossed product is a crossed product by a semigroup action.

J. C. Campuzano, H. Ding, M. R. Norman, M. Randeria

Particle-hole (p-h) mixing is a fundamental consequence of the existence of a pair condensate. We present direct experimental evidence for p-h mixing in the angle-resolved photoemission (ARPES) spectra in the superconducting state of Bi_2Sr_2CaCu_2O_{8+δ}. In addition to its pedagogical importance, this establishes unambiguously that the gap observed in ARPE

I. I. Mazin, A. Golubov

We discuss various mechanisms that can lead to interband sign reversal of the order parameter in a multiband superconductor. In particular, we generalize Abrikosov-Gor&#39;kov solution of the problem of weakly coupled superconductor with magnetic and nonmagnetic impurities on the case of arbitary order parameter anisotropy, including extreme cases as $d-$pai

I. G. Lang, A. V. Prokhorov, M. Cardona, V. I. Belitsky

A combined scattering mechanism involving the states of free electron-hole pairs (exciton continuum) and discrete excitons as intermediate states in the multi-phonon Raman scattering leads to (1) a strong increase of the scattering efficiency in the presence of a high magnetic field and to (2) an outgoing excitonic resonance: the two features are not compati

Pierre Pujol

Using 2-loop renormalisation group calculations, we study a system of $N$ two-dimensional Potts models with random bonds coupled together by their local energy density. This model can be seen as a generalization of the random Ashkin-Teller model. We found that, depending on the sign of the coupling term, the universality class of the system in the presence o

Michael Lassig

A miscut (vicinal) crystal surface can be regarded as an array of meandering but non-crossing steps. Interactions between the steps are shown to induce a faceting transition of the surface between a homogeneous Luttinger liquid state and a low-temperature regime consisting of local step clusters in coexistence with ideal facets. This morphological transition

Valerio Faraoni

We study the prescriptions for the coupling constant of a scalar field to the Ricci curvature of spacetime in specific gravity and scalar field theories. The results are applied to the most popular inflationary scenarios of the universe; their theoretical consistency and certain observational constraints are discussed.

J. B. Hutchings, A. C. Gower, S. Ryneveld, A. Dewey

VLA B-configuration snapshots have been obtained at 6cm and 20cm of 43 radio quasars with a range of known galaxy cluster environments. The radio sources are characterised by measures of morphology, flux, and size. These are studied as a function of cluster density, characterised by published Bgq numbers. We find no strong dependence of radio source properti

C. G. S. Costa, F. Halzen, J. Bellandi, C. Salles

We show that the simplest assumptions for the dynamics of particle production allow us to understand the fluxes of hadrons and photons at mountain altitudes as well as the structure of individual events. The analysis requires a heavy nuclear component of primary cosmic rays above the ``knee" in the spectrum with average mass number $<A> = 7.3 \pm 0.9$.

S. Bonazzola, E. Gourgoulhon

The gravitational wave emission by a distorted rotating fluid star is computed. The distortion is supposed to be symmetric around some axis inclined with respect to the rotation axis. In the general case, the gravitational radiation is emitted at two frequencies: $Ω$ and $2Ω$, where $Ω$ is the rotation frequency. The obtained formulæ are applied to the speci

Dave Syer, Scott Tremaine

Galaxies exhibit a variety of non-axisymmetric structure (bars, spiral structure, lopsided structure, etc.). These suggest the following general problem: what are the possible stationary configurations of a two-dimensional self-gravitating fluid other than an axisymmetric razor-thin disc? We address a modest component of this problem: we seek non-axisymmetri

Y. A. Drozd, G. -M. Greuel

We show that the number of parameters for CM-modules of prescribed rank is semi-continuous in families of CM rings of Krull dimension 1. This transfers a result of Knoerrer from the commutative to the not necessarily commutative case. For this purpose we introduce the notion of ``dense subrings&#39;&#39; which seems rather technical but, nevertheless, useful

Juan C. Gallardo, Robert B. Palmer

The present scenario for a high luminosity 4 TeV on center of mass muon collider requires a beta function =3 mm at the interaction point. We discuss a test model of a basic layout which satisfies the requirements although it is not fully realistic.

F. Aldabe, A. L. Larsen

In a recent paper Townsend suggested to associate to the D=11 solitonic membrane of N=1 supergravity a certain thickness, and then to identify this membrane with the fundamental supermembrane. By integrating out the 8 transverse dimensions of the &#34;thick&#34; solitonic membrane, we show that the resulting world-volume action indeed contains all the usual

Chetan Nayak, Frank Wilczek

We discuss the quantum numbers of domain walls of minimal length induced by doping Mott insulators, carefully distinguishing between holon and hole walls. We define a minimal wall hypothesis that uniquely correlates the observed spatial structure with the doping level for the low-temperature commensurate insulating state of La$_{2-x}$Ba$_x$CuO$_4$ and relate

Neil J. Cornish, David N. Spergel, Glenn D. Starkman

If the universe is finite and smaller than the distance to the surface of last scatter, then the signature of the topology of the universe is writ on the microwave background sky. Previous efforts to search for this topology have focused on one particular model: a toroidal flat universe. We show how both the high degree of spatial symmetry of this topology a

Z. Kunszt, J. W. Stirling, A. Ballestrero, S. Banerjee

Previous studies of the physics potential of LEP2 indicated that with the design luminosity of 500 inverse picobarn one may get a direct measurement of the mass of the W-boson with a precision in the range 30 - 50 MeV. This report presents an updated evaluation of the estimated error on the mass of the W-boson based on recent simulation work and improved the

O. Lund Bo, Yu. Galperin

Low frequency shot noise and dc current profiles for a double-barrier resonant-tunneling structure (DBRTS) under a strong magnetic field applied perpendicular to the interfaces have been studied. Both the structures with 3D and 2D emitter have been considered. The calculations, carried out with the Keldysh Green&#39;s function technique, show strong dependen

C. Arvanitis, R. Tzani

Aiming towards understanding the question of the discrete states in the light-cone gauge in the theory of two-dimensional strings with a linear background charge term, we study the path-integral formulation of the theory. In particular, by gauge fixing Polyakov&#39;s path-integral expression for the 2-d strings, we show that the light-cone gauge-fixed genera

Angel Ballesteros, Francisco J. Herranz

All coboundary Lie bialgebras and their corresponding Poisson--Lie structures are constructed for the oscillator algebra generated by $\{å,\ap,\am,\bb\}$. Quantum oscillator algebras are derived from these bialgebras by using the Lyakhovsky and Mudrov formalism and, for some cases, quantizations at both algebra and group levels are obtained, including their

Steven J. Sturner, Charles D. Dermer

The unusual properties of the bursting X-ray pulsar GRO J1744-28 are explained in terms of a low-mass X-ray binary system consisting of an evolved stellar companion transferring mass through Roche-lobe overflow onto a neutron star, implying that the inclination of the system is < 18 degrees. Interpretation of the QPO at frequency nu(QPO) = 40 Hz using the be

B. Basu-Mallick

We consider a $A_{N-1}$ type of spin dependent Calogero-Sutherland model, containing an arbitrary representation of the permutation operators on the combined internal space of all particles, and find that such a model can be solved as easily as its standard $su(M)$ invariant counterpart through the diagonalisation of Dunkl operators. A class of novel represe

P. Rosenqvist, N. D. Whelan, A. Wirzba

We study the effect on quantum spectra of the existence of small circular disks in a billiard system. In the limit where the disk radii vanish there is no effect, however this limit is approached very slowly so that even very small radii have comparatively large effects. We include diffractive orbits which scatter off the small disks in the periodic orbit ex

Takashi Yamamoto, Osamu Tsuchiya

A new integrable spin chain of the Haldane-Shastry type is introduced. It is interpreted as the inverse-square interacting spin chain with a {\it reflecting end}. The lattice points of this model consist of the square roots of the zeros of the Laguerre polynomial. Using the ``exchange operator formalism&#39;&#39;, the integrals of motion for the model are ex

A. Pineda, J. Soto

We analyse the possible existence of non-perturbative contributions in heavy $\bar Q Q$ systems ($\bar Q$ and $Q$ need not have the same flavour) which cannot be expressed in terms of local condensates. Starting from QCD, with well defined approximations and splitting properly the fields into large and small momentum components, we derive an effective lagran

Andrew Strominger

Extremal BPS-saturated black holes in $N=2$, $d=4$ supergravity can carry electric and magnetic charges $(q^Λ_{(m)},q_Λ^{(e)})$. It is shown that in smooth cases the moduli fields at the horizon take a fixed &#34;rational&#34; value $X^Λ(q_{(m)},q^{(e)})$ which is determined by the charges and is independent of the asymptotic values of the moduli fields. A u

M. S. Marinov, Bilha Segev

One-dimensional quantum scattering from a local potential barrier is considered. Analytical properties of the scattering amplitudes have been investigated by means of the integral equations equivalent to the Schrodinger equations. The transition and reflection amplitudes are expressed in terms of two complex functions of the incident energy, which are simila

G. N. Throumoulopoulos, D. Pfirsch

The conditions for the existence of negative-energy perturbations (which could be nonlinearly unstable and cause anomalous transport) are investigated in the framework of linearized collisionless Maxwell-drift kinetic theory for the case of equilibria of magnetically confined, circularly cylindrical plasmas and vanishing initial field perturbations. For wave

Peter G. Blunden, Gerald A. Miller

A Quark-Meson Coupling (QMC) model is extended to finite nuclei in the relativistic mean-field or Hartree approximation. The ultra-relativistic quarks are assumed to be bound in non-overlapping nucleon bags, and the interaction between nucleons arises from a coupling of vector and scalar meson fields to the quarks. We develop a perturbative scheme for treati

M. Baldo, G. F. Burgio, A. Rapisarda, P. Schuck

We analyze the behavior of a gas of classical particles moving in a two-dimensional &#34;nuclear&#34; billiard whose multipole-deformed walls undergo periodic shape oscillations. We demonstrate that a single particle Hamiltonian containing coupling terms between the particles&#39; motion and the collective coordinate induces a chaotic dynamics for any multip

Bert van Geemen, Jaap Top

This paper gives an expository account of our experiments concerning relations between modular forms for congruence subgroups of SL(3,Z) and three dimensional Galois representations. The main new result presented here is a calculation of the variations of the Hodge structure corresponding to the motives we consider in realizing the Galois representations. It

Roelof Koekoek, René F. Swarttouw

We list the so-called Askey-scheme of hypergeometric orthogonal polynomials. In chapter 1 we give the definition, the orthogonality relation, the three term recurrence relation and generating functions of all classes of orthogonal polynomials in this scheme. In chapeter 2 we give all limit relation between different classes of orthogonal polynomials listed i

Juris Steprāns

To any metric space it is possible to associate the cardinal invariant corresponding to the least number of rectifiable curves in the space whose union is not meagre. It is shown that this invariant can vary with the metric space considered, even when restricted to the class of convex subspaces of separable Banach spaces. As a corollary it is obtained that i

Randall Dougherty

Results of Sierpinski and others have shown that certain finite-dimensional product sets can be written as unions of subsets, each of which is "narrow" in a corresponding direction; that is, each line in that direction intersects the subset in a small set. For example, if the set (omega \times omega) is partitioned into two pieces along the diagonal, then on

B. Geyer, S. D. Odintsov

Using the renormalization group (RG) approach and the equivalency between the class of gauge-Higgs-Yukawa models and the gauged Nambu-Jona-Lasinio (NJL) model, we study the gauged NJL model in curved space-time. The behaviour of the scalar-gravitational coupling constant $ξ(t)$ in both theories is discussed. The RG improved effective potential of gauged NJL

P. S. Howe, G. Papadopoulos

We construct the twistor space associated with an HKT manifold, that is, a hyper-Kähler manifold with torsion, a type of geometry that arises as the target space geometry in two-dimensional sigma models with (4,0) supersymmetry. We show that this twistor space has a natural complex structure and is a holomorphic fibre bundle over the complex projective line

John Sender

SUSY events in which a light stop decays to a chargino may manage to pass the cuts designed for top counting experiments at the Tevatron with no significant diminution of signal. Events in which a top decays via stop are detected with fair efficiency compared to SM top events when $\stop\into b\wino$. More importantly, direct pair production of light stops c

Gustavo Burdman, Joachim Kambor

We study the semileptonic decays of heavy mesons into light pseudoscalars by making use of dispersion relations. Constraints from heavy quark symmetry, chiral symmetry and perturbative QCD are implemented into a dispersive model for the form-factors. Large deviations from $B^*$-pole dominance are observed in $B\toπ\ellν$. We discuss the model prediction for

W. Beenakker, F. A. Berends, E. N. Argyres, D. Bardin

We present the results obtained by the &#34;WW Cross-sections and Distributions&#34; working group during the CERN Workshop &#34;Physics at LEP2&#34; (1994/1995)

S. Dimopoulos, G. F. Giudice

We argue that theories in which supersymmetry breaking originates at low energies often contain scalar particles that mediate coherent gravitational strength forces at distances less than a cm. We estimate the strength and range of these forces in several cases. Present limits on such forces are inadequate. However new techniques, such as those based on smal

Stephen P. Martin

In the minimal supersymmetric standard model, the conservation of R-parity is phenomenologically desirable, but is ad hoc in the sense that it is not required for the internal consistency of the theory. However, if B-L is gauged at very high energies, R-parity will be conserved automatically and exactly, provided only that all order parameters carry even int

G. H. Arakelyan, C. Pajares, Yu. M. Shabelski

A resently developed generalization of the Quark--Gluon String Model to the case of bosonic resonances production in hadron--hadron collisions is used for the calculation of inclusive production of charmed mesons $D$, $D^*(2010)$ and $D^{*}_{2}(2460)$. A simple relation which determines the dependence of the charmed meson production cross sections on their s

A. V. Berezhnoy, V. V. Kiselev, A. K. Likhoded

In the leading $O(α_s^4)$ order of the perturbative QCD, the hadronic production cross-sections of $S$- and $P$-wave states of $B_c$ meson are calculated. The results for the $S$-wave levels are compared with the values given in other papers as well as in the model of the $b$ quark fragmenatation into $B_c$. In the given order, the cross-sections of the hadr

M. Takizawa, Y. Nemoto, M. Oka

We study the $η\to γγ$ and $η\to π^0 γγ$ decays using an extended three-flavor Nambu-Jona-Lasinio model that includes the &#39;t~Hooft instanton induced interaction. We find that the $η$-meson mass, the $η\to γγ$ decay width and the $η\to π^0 γγ$ decay width are in good agreement with the experimental values when the $U_{A}(1)$ breaking is strong and the fla

Jorgen Randrup

The statistical equilibrium properties of the linear sigma model are studied, with a view towards characterizing the field configurations employed as initial conditions for numerical simulations of the formation of disoriented chiral condensates in high-energy nuclear collisions. The field is decomposed into its spatial average (the order parameter) and the

Osamu Yasuda

Using the published Kamiokande data of the multi-GeV atmospheric neutrinos, we have searched the optimum set of the neutrino oscillation parameters among three flavors. It is found that $χ^2$ is minimized for ($Δm_{21}^2$, $Δm_{31}^2$) = (3.8$\times 10^{-2}~$eV$^2$, 1.4$\times 10^{-2}~$eV$^2$), ($θ_{12}$, $θ_{13}$, $θ_{23}$) = ($19^\circ$,$43^\circ$,$41^\cir

M. Milovanovic, N. Read

The Hilbert spaces of the edge excitations of several ``paired&#39;&#39; fractional quantum Hall states, namely the Pfaffian, Haldane-Rezayi and 331 states, are constructed and the states at each angular momentum level are enumerated. The method is based on finding all the zero energy states for those Hamiltonians for which each of these known ground states

C. D. Sfatos, A. M. Gutin, E. I. Shakhnovich

We study a blend of two kinds of homopolymers with tendency for segragation. Cross-links between the chains of different kinds do not allow macrophase separation. Instead microphase structure appears. Starting from a microscopic model we derive the effective Hamiltonian and calculate the form of the inverse scattering function and the domain size. The latter

B. P. van Zyl, R. J. Gooding

We have constructed a complete hydrodynamic theory of nucleation and growth in a one--dimensional version of an elastic shear martensitic transformation with open boundary conditions where we have accounted for interfacial energies with strain--gradient contributions. We have studied the critical martensitic nuclei for this problem: Interestingly, the bulk c

Maria de Sousa Vieira

We study statistical distributions in a mechanical model for an earthquake fault introduced by Burridge and Knopoff [R. Burridge and L. Knopoff, {\sl Bull. Seismol. Soc. Am.} {\bf 57}, 341 (1967)]. Our investigations on the size (moment), time duration and number of blocks involved in an event show that exponential distributions are found in a given range of

S. Mertens

The VC dimension of the Ising perceptron with binary patterns is calculated by numerical enumerations for system sizes N <= 31. It is significantly larger than N/2. The data suggest that there is probably no well defined asymptotic behaviour for N to infinity.

D. W. Snoke, M. Cardona, S. Sanguinetti, G. Benedek

We present a comparison of the bond polarizabilities for carbon-carbon bonds in hydrocarbons and fullerenes, using two different models for the fullerene Raman spectrum and the results of Raman measurements on ethane and ethylene. We find that the polarizabilities for single bonds in fullerenes and hydrocarbons compare well, while the double bonds in fullere

M. J. M. de Jong, C. W. J. Beenakker

A semiclassical theory is developed for time-dependent current fluctuations in mesoscopic conductors. The theory is based on the Boltzmann-Langevin equation for a degenerate electron gas. The low-frequency shot-noise power is related to classical transmission probabilities at the Fermi level. For a disordered conductor with impurity scattering, it is shown h

M. I. Salkola, V. J. Emery, S. A. Kivelson

The consequences of disordered charge stripes and antiphase spin domains for the properties of the high-temperature superconductors are studied. We focus on angle-resolved photoemission spectroscopy and optical conductivity, and show that the many unusual features of the experimentally observed spectra can be understood naturally in this way. This interpreta

Satoshi Fujimoto, Norio Kawakami

Recently Kawabata found that the conductance in Tomonaga-Luttinger (TL) liquids should not be renormalized if one incorporates the renormalization of applied fields correctly. This claim is generalized to include the interactions which carry the large momentum transfer. We thus find that Kawabata&#39;s conclusion holds generally for the class of TL liquids.