September 1996 arXiv papers — page 10

May Chiao, Benoit Lussier, Brett Ellman, Louis Taillefer

We present preliminary measurements of the thermal conductivity of the heavy fermion superconductor UPd$_2$Al$_3$ for the normal and superconducting states at low temperatures. As T$\to$0, the superconducting state is characterized by a finite linear term, about 10% of the normal state value, which suggests a residual density of low energy quasiparticle stat

Y. Alhassid, J. N. Hormuzdiar, N. D. Whelan

Closed expressions are derived for the resonance widths and Coulomb blockade conductance peak heights in quantum dots for the crossover regime between conserved and broken time-reversal symmetry. The results hold for leads with any number of possibly correlated and inequivalent channels. Our analytic predictions are in good agreement with simulations of both

T. Giamarchi

I review some of the results on the Mott transition in one dimensional systems. In particular I discuss the phase diagram and critical properties of both Mott transitions at fixed filling and upon doping, as well as the dc and ac conductivity. Application of these results to organic conductors is discussed.

B. Subramanian, G. T. Barkema, J. L. Lebowitz, E. R. Speer

We have carried out extensive computer simulations of one-dimensional models related to the low noise (solid-on-solid) non-equilibrium interface of a two dimensional anchored Toom model with unbiased and biased noise. For the unbiased case the computed fluctuations of the interface in this limit provide new numerical evidence for the logarithmic correction t

T. Giamarchi, P. Le Doussal

We review the prediction, made in a previous work [Phys. Rev. B 52 (1995)], that the phase diagram of type II superconductors consists of a topologically ordered Bragg glass phase at low fields undergoing a transition at higher fields into a vortex glass or a liquid. We estimate the position of the phase boundary using a Lindemann criterion. We find that the

R. Martonak, D. Marx, P. Nielaba

The orientational ordering transition is investigated in the quantum generalization of the anisotropic-planar-rotor model in the low temperature regime. The phase diagram of the model is first analyzed within the mean-field approximation. This predicts at $T=0$ a phase transition from the ordered to the disordered state when the strength of quantum fluctuati

Magnus Rattray, Jonathan Shapiro

A formalism for describing the dynamics of Genetic Algorithms (GAs) using methods from statistical mechanics is applied to the problem of generalization in a perceptron with binary weights. The dynamics are solved for the case where a new batch of training patterns is presented to each population member each generation, which considerably simplifies the calc

F. Brosens, J. T. Devreese, L. F. Lemmens

A generalization of symmetrized density matrices in combination with the technique of generating functions allows to calculate the partition function of identical particles in a parabolic confining well. Harmonic two-body interactions (repulsive or attractive) are taken into account. Also the influence of a homogeneous magnetic field, introducing anisotropy

Antimo Angelucci, Sandro Sorella

We present a generalization of the Sutherland's multicomponent model. Our extension includes both the ferromagnetic and the antiferromagnetic t-J model for any value of the exchange coupling J and the hopping parameter t. We prove rigorously that for one dimensional chains the ground-state of the generalized model is non-degenerate. As a consequence, the

I. V. Yurkevich, V. E. Kravtsov

The level curvature distribution function is studied beyond the random matrix theory for the case of T-breaking perturbations over the orthogonal ensemble. The leading correction to the shape of the level curvature distribution is calculated using the nonlinear sigma-model. The sign of the correction depends on the presence or absence of the global gauge inv

E. Balkovsky

We find explicitly a zero mode of the Kraichnan operator at two dimensions.

Timothy R. Bedding

This tutorial gives a general introduction to optical and infrared interferometry, specifically addressing two questions: `Can I use VLTI to observe my favourite object?' and `What will it tell me?' The observables measured by an interferometer are fringe visibility and closure phase, which can then be fitted by a model or used to reconstruct an imag

Paolo Padoan, Raul Jimenez, Vincenzo Antonuccio-Delogu

We reconsider the problem of the age of the stellar discs of late-type Low Surface Brightness (LSB) galaxies by making use of a new IMF recently derived from numerical fluid dynamical simulations (Padoan, Nordlund and Jones, 1997). While a Miller-Scalo IMF cannot adequately describe the photometric properties of LSBs, when we apply the new Padoan et al. (199

L. W. Neuschaefer, M. Im, K. U. Ratnatunga, R. E. Griffiths

We examine the morphological and statistical properties of close galaxy pairs from two sets of 28 WFPC2 fields, acquired for the Medium Deep Survey (MDS) and the Groth/Westphal Survey (GWS) in F606W (V) and F814W (I) passbands. In the GWS sample all fields have uniform 95% completeness down to I<=24.3 mag, whereas in the MDS sample, fields have varying 95% c

R. P. Saglia, E. Bertschinger, G. Baggley, D. Burstein

The EFAR project is a study of 736 candidate early-type galaxies in 84 clusters lying in two regions towards Hercules-Corona Borealis and Perseus-Cetus at distances $cz \approx 6000-15000$ km/s. In this paper we describe a new method of galaxy photometry adopted to derive the photometric parameters of the EFAR galaxies. The algorithm fits the circularized su

Giuseppe Bono, Filippina Caputo, Vittorio Castellani, Marcella Marconi

Double-mode RR Lyrae variables (i.e. radial variables which are simultaneously pulsating in both fundamental and first overtone modes) appear a fundamental tool for investigating the mass of old Population II Horizontal Branch (HB) stars. The most widespread method adopted for evaluating the masses of these objects is based on the Petersen (1973) approach, w

Giuseppe Bono, Filippina Caputo, Santi Cassisi, Vittorio Castellani

We investigate the modal stability of stellar models at masses and luminosity levels corresponding to post main sequence luminous delta scuti pulsators. The envelope models have been computed at fixed mass value, luminosity level and chemical composition (Y=0.28, Z=0.02). According to a nonlinear approach to radial oscillations the present investigation pred

Frank Sottile

We discuss the problem of whether a given problem in enumerative geometry can have all of its solutions be real. In particular, we describe an approach to problems of this type, and show how this can be used to show some enumerative problems involving the Schubert calculus on Grassmannians may have all of their solutions be real. We conclude by describing th

Frank Ferrari

It is shown that the physical ``quark number&#39;&#39; charges which appear in the central charge of the supersymmetry algebra of $N=2$ supersymmetric QCD can take irrational values and depend non trivially on the Higgs expectation value. This gives a physical interpretation of the constant shifts which the ``electric&#39;&#39; and ``magnetic&#39;&#39; varia

Alexander Kusenko, Kimyeong Lee, Erick J. Weinberg

We study the effects of internal symmetries on the decay by bubble nucleation of a metastable false vacuum. The zero modes about the bounce solution that are associated with the breaking of continuous internal symmetries result in an enhancement of the tunneling rate into vacua in which some of the symmetries of the initial state are spontaneously broken. We

H. -J. He, W. B. Kilgore

The electroweak equivalence theorem quantitatively connects the physical amplitudes of longitudinal massive gauge bosons to those of the corresponding ``unphysical&#39;&#39; would-be Goldstone bosons. Its precise form depends on both the gauge fixing condition and the renormalization scheme. Our previous modification-free schemes have applied to a broad clas

E. J. Ferrer, V. de la Incera

The boundary effects in the screening of an applied magnetic field in a finite temperature 2+1 dimensional model of charged fermions minimally coupled to Maxwell and Chern-Simons fields are investigated. It is found that in a sample with only one boundary -a half-plane- a total Meissner effect takes place, while in a sample with two boundaries -an infinite s

James B. Hartle, Warner A. Miller, Ruth M. Williams

We investigate the signature of the Lund-Regge metric on spaces of simplicial three-geometries which are important in some formulations of quantum gravity. Tetrahedra can be joined together to make a three-dimensional piecewise linear manifold. A metric on this manifold is specified by assigning a flat metric to the interior of the tetrahedra and values to t

G. Papadopoulos, P. K. Townsend

The M-theory interpretation of certain D=10 IIA p-branes implies the existence of worldvolume Kaluza-Klein modes which are expected to appear as 0-brane/p-brane bound states preserving 1/4 of the spacetime supersymmetry. We construct the corresponding solutions of the effective supergravity theory for $p=1,4$, and show that no such solution exists for $p=8$.

C. Syros, C. Schulz-Mirbach

A quantum time topological space is developed and applied to solve some problems about quantum theory. It is disconnected and satifies specific separation axioms. The degree of disconnectedness of the time-space is a decreasing function of the number of simultaneous or almost simultaneous fundamental interactions. In this topology the U+R Penrose dynamics is

B. Alles, A. Buonanno, G. Cella

We reply to a comment by A. Patrascioiu and E. Seiler appeared in hep-lat/9608138 on our paper hep-lat/9608002.

S. A. van Langen, P. W. Brouwer, C. W. J. Beenakker

The functional defined as the squared modulus of the spatial average of the wave function squared, plays the role of an ``order parameter&#39;&#39; for the transition between Hamiltonian ensembles with orthogonal and unitary symmetry. Upon breaking time-reversal symmetry, the order parameter crosses over from one to zero. We compute its distribution in the c

Nemanja Kaloper

We discuss a particular stringy modular cosmology with two axion fields in seven space-time dimensions, decomposable as a time and two flat three-spaces. The effective equations of motion for the problem are those of the $SU(3)$ Toda molecule, and hence are integrable. We write down the solutions, and show that all of them are singular. They can be thought o

A. Borowiec, V. K. Kharchenko, Z. Oziewicz

The purpose of this note is to show how calculi on unital associative algebra with universal right bimodule generalize previously studied constructions by Pusz and Woronowicz [1989] and by Wess and Zumino [1990] and that in this language results are in a natural context, are easier to describe and handle. As a by--product we obtained intrinsic, coordinate--f

M. Gyulassy, D. H. Rischke, B. Zhang

As a result of multiple mini-jet production, initial conditions of the QCD plasma formed in ultrarelativistic nuclear collisions may be inhomogeneous, with large fluctuations of the local energy density (hot spots), and turbulent, with a chaotic initial transverse velocity field. Assuming rapid local thermalization, the evolution of such plasmas is computed

Ulrich Heinz

I discuss two-particle intensity interferometry as a method to extract from measured 1- and 2-particle momentum spectra information on the space-time geometry and dynamics of the particle emitting source. Particular attention is given to the rapid expansion and short lifetime of the sources created in relativistic heavy-ion collisions. Model-independent expr

A. P. Vischer

The energy densities achieved during central collisions of large nuclei at the AGS may be high enough to allow the formation of quark--gluon plasma. We propose that most collisions at AGS energies produce superheated hadronic matter, but in rare events a droplet of quark--gluon plasma is nucleated. We estimate the probability of this to occur based on homoge

A. Fabrocini

The electromagnetic inclusive transverse response of nuclear matter at saturation density is studied within the correlated basis function perturbation theory for momentum transfers q from 300 to 550 MeV/c. The correlation operator includes a Jastrow component, accounting for the short range repulsion, as well as longer range spin, tensor and isospin ones. Th

Frank Wilczek

I discuss how the basic phenomenon of asymptotic freedom in QCD can be understood in elementary physical terms. Similarly, I discuss how the long-predicted phenomenon of ``gluonization of the proton&#39;&#39; -- recently spectacularly confirmed at HERA -- is a rather direct manifestation of the physics of asymptotic freedom. I review the broader significance

Oren Bergman

We review work done in collaboration with C.B. Thorn on Super-Galilei invariant field theory and its application to the reformulation of superstring theory in terms of constituent superstring-bits.

E. J. Ferrer, V. de la Incera

The boundary effects in the screening of an applied magnetic field in a charged anyon fluid at finite temperature and density are investigated. By analytically solving the extremum equations of the sytem and minimizing the free energy density, we find that in a sample with only one boundary (the half plane), a total Meissner effect takes place; while the sam

Ramzi R. Khuri

$P$-brane solutions of low-energy string actions have traditionally provided the first evidence for the existence of string dualities, in which fundamental and solitonic $p$-branes are identified with perturbative and non-perturbative BPS states. In this talk we discuss the composite nature of solutions, which allows for the interpretation of general solutio

Dimitri Polyakov

The paper analyzes the problem fixing the local fermionic gauge symmetry in the Green-Schwarz superstring theory,related to the covariant quantization of this theory.The gauge-fixing procedure reveals the connection between GS and NSR formalisms, conjectured earlier. The analysis relates the kappa-invariance to the Bogomol&#39;ny-type condition,well-known in

Gaetano Lambiase

Quantum Field Theory (QFT) developed in Rindler space-time and its thermal properties are analyzed by means of quantum groups approach. The quantum deformation parameter, labelling the unitarily inequivalent representations, turns out to be related to the acceleration of the Rindler frame.

E. A. Ivanov

We sketch recent applications of the harmonic superspace approach for off-shell formulations of $(4,4)$, $2D$ sigma models with torsion and for constructing super KdV hierarchies associated with &#34;small&#34; and &#34;large&#34; $N=4$ superconformal algebras.

Shogo Tanimura, Izumi Tsutsui

A path-integral quantization on a homogeneous space G/H is proposed based on the guiding principle `first lift to G and then project to G/H&#39;. It is then shown that this principle gives a simple procedure to obtain the inequivalent quantizations (superselection sectors) along with the holonomy factor (induced gauge field) found earlier by algebraic approa

Shin&#39;ichi Nojiri

We consider the quantum correction to the Lagrangean by the massless free boson in the curved background in three dimensions where one of the coordinates is periodic. The correction term is given by an expansion of the metric with respect to the derivative and the first term expresses to the usual Casimir energy. As an application, we investigate the change

Ergin Sezgin

We construct a new extension of the Poincaré superalgebra in eleven dimensions which contains super one-, two- and five-form charges. The latter two are associated with the supermembrane and the superfivebrane of M-theory. Using the Maurer-Cartan equations of this algebra, we construct closed super seven-forms in a number of ways. The pull-back of the corres

J. M. Cline

I summarize work done with Bamert, Burgess, Nardi and London in which we examine the effects of new physics on R_b. Our work facilitates the identification of such new physics in case the present two-sigma deviation of R_b from its Standard Model value should persist, or alternatively it helps to constrain new physics in case the discrepancy continues to dis

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

We investigate the connection between the NSVZ and the DRED forms of the gauge $β$-function in an $N=1$ supersymmetric gauge theory. We construct a coupling constant redefinition that relates the two forms up to four loops. By abelian calculations, we are able to infer the complete non-abelian form of $β_g^{(3)DRED}$, and also $β_g^{(4)DRED}$ except for one

Andrzej J. Buras

We review several aspects of K-Physics: i) Main targets of the field, ii) The theoretical framework for K-decays, iii) Standard analysis of the unitarity triangle, iv) epsilon&#39;/epsilon, v) Rare and CP violating K-decays, vi) Comparision of the potentials of K --> pi nu nu-bar and CP-B asymmetries. vii) Some aspects of the physics beyond the Standard Mode

S. A. Abel

The problem of destabilising divergences is discussed for singlet extensions of the MSSM. It is shown that models which possess either gauged-$R$ symmetry or target space duality at the Planck scale are able to circumvent this problem whilst avoiding cosmological domain walls.

Wolfgang Lucha, Franz F. Schöberl

The spinless Salpeter equation may be considered either as a standard approximation to the Bethe--Salpeter formalism, designed for the description of bound states within a relativistic quantum field theory, or as the most simple, to a certain extent relativistic generalization of the costumary nonrelativistic Schrödinger formalism. Because of the presence of

D. G. Charlton, G. Montagna, O. Nicrosini, F. Piccinini

The Monte Carlo program {\tt WWGENPV}, designed for computing distributions and generating events for four-fermion production in $e^+ e^- $ collisions, is described. The new version, 2.0, includes the full set of the electroweak (EW) tree-level matrix elements for double- and single-$W$ production, initial- and final-state photonic radiation including $p_T /

Costas G. Papadopoulos

This paper is a long write-up of ERATO. ERATO is a Monte Carlo event generator describing four fermion production at LEP2 and beyond. All tree-order processes leading to four fermions are included, taking into account all relevant QCD contributions. QED higher order corrections are introduced via a structure function approach, whereas weak corrections relate

Robert M. Harris

If quarks are composite particles then excited states are expected. We estimate the discovery mass reach as a function of integrated luminosity for excited quarks decaying to dijets at the Tevatron, LHC, and a Very Large Hadron Collider (VLHC). At the Tevatron the mass reach is 0.94 TeV for Run II (2 fb^-1) and 1.1 TeV for TeV33 (30 fb^-1). At the LHC the ma

Robert M. Harris

In topcolor assisted technicolor, topgluons are massive gluons which couple mainly to top and bottom quarks. We estimate the mass reach for topgluons decaying to t anti-t at the Tevatron as a function of integrated luminosity. The mass reach for topgluons decreases with increasing topgluon width, and is 1.0 - 1.1 TeV for Run II (2 fb^-1) and 1.3-1.4 TeV for

K. Funakubo, A. Kakuto, S. Otsuki, K. Takenaga

We study the CP-violating bubble wall by solving the coupled equations of motion derived from the two-Higgs-doublet model for the moduli $ρ_i$ and phases $θ_ i$ of the two scalars $(i=1,2)$ at the transition temperature. We find a solution that the CP-violating phase $θ\equivθ_1-θ_2$ connecting the CP-conserving vacua strongly violates CP in the intermediate

Robert M. Harris

In topcolor assisted technicolor, topgluons are massive gluons which couple mainly to top and bottom quarks. We estimate the mass reach for topgluons decaying to b anti-b at the Tevatron as a function of integrated luminosity. The mass reach for topgluons decreases with increasing topgluon width, and is 0.77 - 0.95 TeV for Run II (2 fb^-1) and 1.0-1.2 TeV fo

B. Alles, A. Feo, H. Panagopoulos

We calculate the third coefficient of the lattice $β$ function in pure Yang-Mills theory. We make use of a computer code for solving perturbation theory analytically on the lattice. We compute the divergent integrals by using a method based on a Taylor expansion of the integrand in powers of the external momenta in $4 - ε$ dimensions. Our results are in agre

Seyong Kim, Shigemi Ohta

We report our quenched staggered light hadron mass calculation at the coupling of β= 6.5 on a 48^3 \times 64 lattice, based on an increased statistics of two hundred gauge configurations. Staggered quark wall sources with mass of m_q a = 0.01, 0.005, 0.0025 and 0.00125 are used. Flavor symmetry is restored for pion and ρmeson. The lattice scale is estimated

A. Bamberger

The ZEUS detector at HERA has been supplemented with a presampler detector in front of the forward and rear calorimeters. It consists of a segmented scintillator array read out with wavelength-shifting fibers. We discuss its desi gn, construction and performance. Test beam data obtained with a prototype presampler and the ZEUS prototype calorimeter demonstra

Lee Samuel Finn

When completed, the gravitational wave detectors now proposed or under construction will provide us with a perspective on the Universe fundamentally different from any we have come to know. With this new perspective comes the hope that new insights and understandings of Nature will emerge. The proposed acoustic detectors, with spherical geometries and operat

A. T. Costa, J. d&#39;Albuquerque e Castro, R. B. Muniz, M. S. Ferreira

The exchange coupling between Fe layers separated by BCC Cu is calculated for Fe/Cu/Fe (001) trilayers. It is shown that the coupling is basically regulated by three extrema of the bulk BCC Cu Fermi surface. The contributions from those extrema are all of the same order of magnitude, but that associated with the ``belly&#39;&#39; at the $Γ$-point dominates.

Peter Neu, Robert J. Silbey

The mechanism of coherent destruction of tunneling found by Grossmann et al. [Phys. Rev. Lett. 67, 516 (1991)] is studied from the viewpoint of quantum optics by considering the photon statistics of a single mode cavity field which is strongly coupled to a two-level tunneling system (TS). As a function of the interaction time between TS and cavity the photon

Yong-Jihn Kim

We review the new theory of impure superconductors constructed by Kim and Overhauser, and further developed by Kim. It was shown that Gor&#39;kov&#39;s self-consistency equation needs a pairing constraint derived from the Anomalous Green&#39;s function. Whereas earlier studies have applied a constraint only on the pair potential, we show that the kernel also

Shu Zhang, Michael Karbach, Gerhard Müller, Joachim Stolze

The impact of the spin-flip terms on the (static and dynamic) charge and spin correlations in the Luttinger-liquid ground state of the 1D $t-J$ model is assessed by comparison with the same quantities in the 1D $t-J_z$ model, where spin-flip terms are absent. We employ the recursion method combined with a weak-coupling or a strong-coupling continued-fraction

S. Grabowski, J. Schmalian, K. H. Bennemann

The normal and superconducting state of YBa_{2}Cu_{3}O_{6+δ} and Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} are investigated by using the mono- and bilayer Hubbard model within the fluctuation exchange approximation and a proper description of the Fermi surface topology. The inter- and intra-layer interactions, the renormalization of the bilayer splitting and the formation

Matthias Vojta, Klaus W. Becker

We present a new approach to static and dynamical properties of holes and spins in weakly doped antiferromagnets in two dimensions. The calculations are based on a recently introduced cumulant approach to ground--state properties of correlated electronic systems. The present method allows to evaluate hole and spin--wave dispersion relations by considering ho

J. M. Deutsch, Tanya Kurosky

We investigate the problem of how to obtain the force field between atoms of an experimentally determined structure. We show how this problem can be efficiently solved, even at finite temperature, where the position of the atoms differs substantially from the ground state. We apply our method to systems modeling proteins and demonstrate that the correct pote

Marco Tavani, Jonathan Arons

We study the physical processes of the PSR B1259-63 system containing a 47 ms pulsar orbiting around a Be star in a highly eccentric orbit. Motivated by the results of a multiwavelength campaign during the January 1994 periastron passage of PSR B1259-63, we discuss several issues regarding the mechanism of high-energy emission. Unpulsed power law emission fr

Sabine Moehler, Uli Heber, Patrick R. Durrell

Quantitative spectroscopic analyses of two faint blue stars (V=19.5-20.0 mag) in the globular cluster M 15 are presented. Their derived Teff, gravities and absolute magnitudes (Teff=24000K, log g=5.2, Mv=4.3; Teff=36000K, log g=5.9, Mv=4.7, respectively) are matched very well by models for the Extreme Horizontal Branch (EHB). Both stars are bona-fide subdwar

Zacharias A. M. Protogeros, Robert J. Scherrer

We compute the skewness $t_3$ and the corresponding hierarchical amplitude $T_3$ of the divergence of the velocity field for arbitrary non-Gaussian initial conditions. We find that $T_3$ qualitatively resembles the corresponding hierarchical amplitude for the density field, $S_3$, in that it contains a term proportional to the initial skewness, which decays

Michael Rauch, Martin G. Haehnelt, Matthias Steinmetz

In hierarchical cosmogonies at redshift three the matter content of a typical present-day galaxy is dispersed over several individual clumps embedded in sheet-like structures, often aligned along filaments. We have used hydrodynamical simulations to investigate the spatial distribution and absorption properties of metal enriched gas in such regions of ongoin

L. J. Greenhill, C. R. Gwinn, R. Antonucci, R. Barvainis

We have made the first VLBI synthesis images of the H2O maser emission associated with the central engine of the Seyfert galaxy NGC 1068. Emission extends about +/-300 km/s from the systemic velocity. Images with submilliarcsecond angular resolution show that the red-shifted emission lies along an arc to the northwest of the systemic emission. (The blue-shif

M. V. Diwan

If dark matter neutral LSPs in the galactic halo decay into two body final states containing photons or neutrinos they could be detected even if the decay rates are very small, 10**{-32} per sec. I calculate mass and lifetime bounds from current astrophysical data on monochromatic photons and neutrinos and suggest that the poorly explored region between 10 G

Dean E. McLaughlin, Ralph E. Pudritz

We present semi-analytical similarity solutions for the inside-out, expansion-wave collapse of initially virialized gas clouds with non-isothermal equations of state. Results are given for the family of negative-index polytropes, but we focus especially on the so-called logotrope, P/P_c=1+A ln(rho/rho_c). The formalism and interpretation of the present theor

Klaus Altmann

For affine toric varieties, the vector space T1 (containing the infinitesimal deformations) will be interpreted via Minkowski summands of cross cuts of the defining polyhedral cone. This result will be applied to study the deformation theory of (in particular non-isolated) three-dimensional Gorenstein singularities.

S. Solomon, M. Levy

We extend a generic class of systems which have previously been shown to spontaneously develop scaling (power law) distributions of their elementary degrees of freedom. While the previous systems were linear and exploded exponentially for certain parameter ranges, the new systems fulfill nonlinear time evolution equations similar to the ones encountered in S

Guillermo Abramson

We present numerical results based on a simplified ecological system in evolution, showing features of extinction similar to that claimed for the biosystem on Earth. In the model each species consists of a population in interaction with the others, that reproduces and evolves in time. Each species is simultaneously a predator and a prey in a food chain. Muta

Robert B. Mann, Sergey N. Solodukhin

We consider the behaviour of a quantum scalar field on three-dimensional Euclidean backgrounds: Anti-de Sitter space, the regular BTZ black hole instanton and the BTZ instanton with a conical singularity at the horizon. The corresponding heat kernel and effective action are calculated explicitly for both rotating and non-rotating holes. The quantum entropy o

S. S. Gubser, I. R. Klebanov

Recently Maldacena and Strominger found that the calculation of greybody factors for $D=5$ black holes carrying three U(1) charges gives striking new evidence for their description as multiply wound effective strings. Here we show that a similar result holds for $D=4$ black holes with four $U(1)$ charges. In this case the effective string may be thought of a

Guo-Hong Wu, John N. Ng

We provide a general analysis of time reversal violation arising from misalignment between quark and squark mass eigenstates. In particular, we focus on the possibility of large enhancement effects due to the top quark mass. For semileptonic decays of the charged mesons, $K^+ \rightarrow π^0 μ^+ ν_μ$, $D^+ \rightarrow \overline{K}^0 μ^+ ν_μ$, and $B^+ \right

Ulrich Nierste

Todays key information on the shape of the unitarity triangle is obtained from the well-measured quantity epsilon_K characterizing the CP-violation in |Delta S|=2 transitions. The phenomenological analysis requires the input of four key quantities: The magnitudes of the CKM elements V_cb and V_ub, the top quark mass and the non-perturbative parameter B_K. In

Chetan Nayak, Frank Wilczek

Several experiments suggest that the charge carriers in the normal state of certain cuprate superconductors reside on domain walls. In an earlier paper, we suggested that several aspects of the anomalous dynamical behavior of these materials could be explained, at least qualitatively, on this basis. Here, using results on the ground state energy of the 1-dim

F. De Fazio

We compute the rate of the decay $B^- \to μ^- {\bar ν}_μγ$ by a QCD relativistic potential model, with the result: ${\cal B}(B^- \to μ^- {\bar ν}_μγ)=0.9 \cdot 10^{-6}$. We also discuss how this decay mode can be used to access $f_B$.

A. Higuchi, G. E. A. Matsas, D. Sudarsky

We show that static sources coupled to a massless scalar field in Schwarzschild spacetime give rise to emission and absorption of zero-energy particles due to the presence of Hawking radiation. This is in complete analogy with the description of the bremsstrahlung by a uniformly accelerated charge from the coaccelerated observers' point of view. The response

A. Konechny, A. Schwarz

We give a new description of N=1 super Yang-Mills theory in curved superspace. It is based on the induced geometry approach to a curved superspace in which it is viewed as a surface embedded into C(4|2). The complex structure on C(4|2) supplied with a standard volume element induces a special Cauchy-Riemann (SCR)-structure on the embedded surface. We give an

E. Halyo, B. Kol, A. Rajaraman, L. Susskind

We review the arguments that fundamental string states are in one to one correspondence with black hole states. We demonstrate the power of the assumption by showing that it implies that the statistical entropy of a wide class of nonextreme black holes occurring in string theory is proportional to the horizon area. However, the numerical coefficient relating

Phillial Oh, Chaiho Rim

We study the relations between $q$-deformations and $q$-coherent states of the single oscillator representations for $su_q(1,1)$ and $su_q(2)$ algebras; Dyson and Holstein-Primakoff type in terms of Biedenharn, Macfarlane and anyonic oscilators. We also discuss the related Fock-Bargmann $q$-derivative and integration.

I. S. Towner

Measured magnetic moments of single-particle states in the Pb region differ significantly from their Schmidt values. We discuss the reasons for this in terms of meson-exchange currents, isobar currents, core polarisation and other effects.

W. Cassing, C. M. Ko

We have carried out a first calculation of $J/Ψ$ production from nuclear collisions within the covariant transport approach HSD, which has been very successful in describing both hadronic and electromagnetic observables from heavy-ion collisions at intermediate and high energies. The production of $J/Ψ$&#39;s is based on the Lund string fragmentation model,

E. Hagberg, J. C. Hardy, V. T. Koslowsky, G. Savard

Precision studies of $0^{+} \rightarrow 0^{+}$ superallowed $β$ decays provide the necessary data to test stringently the CVC hypothesis. They will also provide a value for the weak vector coupling constant and the $V_{ud}$ quark mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. The determination of this element is crucial for the test of the uni

J. Brian Conrey, William Duke, David W. Farmer

For each prime $p$, we determine the distribution of the $p^{th}$ Fourier coefficients of the Hecke eigenforms of large weight for the full modular group. As $p\to\infty$, this distribution tends to the Sato--Tate distribution.

Finn Larsen, Frank Wilczek

After emphasizing the importance of obtaining a space-time understanding of black hole entropy, we further elaborate our program to identify the degrees of freedom of black holes with classical space-time degrees of freedom. The Cvetič-Youm dyonic black holes are discussed in some detail as an example. In this example hair degrees of freedom transforming as

V. Aldaya, M. Calixto, M. Navarro

Quantizing the electromagnetic field with a group formalism faces the difficulty of how to turn the traditional gauge transformation of the vector potential, $A_μ(x)\rightarrow A_μ(x)+\partial_μφ(x)$, into a group law. In this paper it is shown that the problem can be solved by looking at gauge transformations in a slightly different manner which, in additio

B. Hunt, M. Lynker, R. Schimmrigk

We discuss the structure of heterotic/type II duality in four dimensions as a consequence of string-string duality in six dimensions. We emphasize the new features in four dimensions which go beyond the six dimensional vacuum structure and pertain to the way particular K3 fibers can be embedded in Calabi-Yau threefolds. Our focus is on hypersurfaces as well

C. Acerbi, G. Mussardo, A. Valleriani

We compute the Form Factors of the relevant scaling operators in a class of integrable models without internal symmetries by exploiting their cluster properties. Their identification is established by computing the corresponding anomalous dimensions by means of Delfino--Simonetti--Cardy sum--rule and further confirmed by comparing some universal ratios of th

Kenichiro Aoki, Eric D&#39;Hoker

We consider scattering amplitudes in non-critical string theory of $N$ external states in the limit where the energy of all external states is large compared to the string tension. We argue that the amplitudes are naturally complex analytic in the matter central charge $c$ and we propose to define the amplitudes for arbitrary value of $c$ by analytic continu

R. Güven, E. Yörük

A class of solutions of the low energy string theory in four dimensions is studied. This class admits a geodesic, shear-free null congruence which is non-twisting but in general diverging and the corresponding solutions in Einstein&#39;s theory form the Robinson-Trautman family together with a subset of the Kundt&#39;s class. The Robinson-Trautman conditions

Toshiaki Aida, Yoshihisa Kitazawa

We perform the two loop level renormalization of quantum gravity in $2+ε$ dimensions. We work in the background gauge whose manifest covariance enables us to use the short distance expansion of the Green&#39;s functions. We explicitly show that the theory is renormalizable to the two loop level in our formalism. We further make a physical prediction for the

U. Baur, S. Keller, W. Sakumoto, D. Wackeroth

Some results of a calculation of electroweak radiative corrections to $W$ and $Z$ boson production in hadronic collisions are presented.

R. Michael Barnett, Lawrence J. Hall

We consider unusual events in the CDF and D0 dilepton+jets sample with very high ET(lepton) and ET(missing). It is possible, but very unlikely, that these events originate from top quark pair production; however, they have characteristics that are better accounted for by decays of supersymmetric quarks with mass in the region of 300 GeV.

W. Koepf, P. V. Landshoff, E. M. Levin, N. N. Nikolaev

The diffractive production of vector mesons in ep interactions at low x is a subject of heated debates. This chapter consists of four contributions written by the original authors and expresses the possible scenarios which are to be investigated experimentally.

Thomas G. Rizzo

Measurements of distributions associated with the pair production of top quarks at the LHC can be used to constrain (or observe) the anomalous chromomagnetic dipole moment($κ$) of the top. For example, using either the $t\bar t$ invariant mass or the $p_t$ distribution of top we find that sensitivities to $|κ|$ of order 0.05 are obtainable with 100 $fb^{-1}$