June 1996 arXiv papers — page 2

S. Gavin, R. Vogt

The first reports of $ψ$ and $ψ'$ production from experiment NA50 at the CERN SPS are compared to predictions based on a hadronic model of charmonium suppression. Data on centrality dependence and total cross sections are in good accord with these predictions.

Ulrich Ellwanger, Manfred Hirsch, Axel Weber

We perform a calculation of the full momentum dependence of the gluon and ghost propagators in pure SU(3) Yang-Mills theory by integrating Wilson's exact renormalization group equations with respect to an infrared cutoff k. The heavy quark potential in the quenched approximation can be expressed in terms of these propagators. Our results strongly indicat

J. Schiøtz, L. M. Canel, A. E. Carlsson

We present a systematic study of the effect of crack blunting on subsequent crack propagation and dislocation emission. We show that the stress intensity factor required to propagate the crack is increased as the crack is blunted by up to thirteen atomic layers, but only by a relatively modest amount for a crack with a sharp 60$^\circ$ corner. The effect of

K. Nandra, I. M. George, R. F. Mushotzky, T. J. Turner

We present evidence for widespread relativistic effects in the central regions of active galactic nuclei. In a sample of 18 Seyfert 1 galaxies observed by \asca, 14 show an iron K$α$ line which is is resolved, with mean width $σ_{\rm Kα}=0.43\pm 0.12$~keV for a gaussian profile (Full Width at Half Maximum, FWHM$\sim 50,000$~km s$^{-1}$). However, many of the

Benjamin Enriquez, Edward Frenkel

We express the Poisson brackets of local fields of the affine Toda field theories in terms of the Drinfeld-Sokolov dressing operator. For this, we introduce a larger space of fields, containing ``half screening charges'' and ``half integrals of motions''. In addition to local terms, the Poisson brackets contain nonlocal terms related to trigo

Stefan Ochs, Ulrich Heinz

We investigate entropy production for an expanding system of particles and resonances with isospin symmetry -- in our case pions and $ρ$ mesons -- within the framework of relativistic kinetic theory. A cascade code to simulate the kinetic equations is developed and results for entropy production and particle spectra are presented.

Thomas R. Hemmert, Barry R. Holstein, Joachim Kambor

Starting from a relativistic formulation of the pion-nucleon-delta system, the most general structure of 1/M corrections for a heavy baryon chiral lagrangian including spin 3/2 resonances is given. The heavy components of relativistic nucleons and delta fields are integrated out and their contributions to the next-to-leaing order lagrangians are constructed

Dipak Munshi, T. Padmanabhan

Padmanabhan (1996) has suggested a model to relate the nonlinear two - point correlation function to the linear two - point correlation function. In this paper, we extend this model in two directions: (1) By averaging over the initial Gaussian distribution of density contrasts, we estimate the spectral dependence of the scaling between nonlinear and linear c

S. Luding, E. Clement, J. Rajchenbach, J. Duran

We present simulations of peak pattern formation in vibrated two-dimensional (2D) granulates and measure the dispersion relation of the pattern for various frequencies, accelerations, cell sizes, and layer heights. We report the first quantitative data from numerical simulations showing an interesting dependence of the pattern wavelength on the acceleration

HongSheng Zhao

The discovery of the Sgr dwarf galaxy (Ibata, Gilmore, Irwin 1994) shows that the Galactic halo contains large clumps which are not full viralized. Stars in such a clump can lense a background extragalactic source. I use parameters of Sgr to demonstrate that microlensing by a disintegrated dwarf galaxy has a probability (optical depth) $10^{-7}-10^{-6}$, whi

HaWoong Jeong, ByungNam Kahng, Doochul Kim

We introduce a self-organized surface growth model in 2+1 dimensions with anisotropic avalanche process, which is expected to be in the universality class of the anisotropic quenched Kardar-Parisi-Zhang equation with alternative signs of the nonlinear KPZ terms. It turns out that the surface height correlation functions in each direction scales distinctively

Masaki Oshikawa, Ian Affleck

Critical phenomena in the two-dimensional Ising model with a defect line are studied using boundary conformal field theory on the $c=1$ orbifold. Novel features of the boundary states arising from the orbifold structure, including continuously varying boundary critical exponents, are elucidated. New features of the Ising defect problem are obtained including

Andre de Gouvea, Hitoshi Murayama

We reanalyze the constraints on light gluinos (m_{\tilde{g}}\leq 5 GeV/c^2) from the hadronic Z decays into four jets. We find that the published OPAL data from the 1991 and 1992 runs exclude a light quasi-stable gluino with mass \lesssim 1.5 GeV/c^2 at more than 90% confidence level. This limit depends little on assumptions about the gluino fragmentation an

R. A. Kraenkel, M. A. Manna, V. Merle, J. C. Montero

By considering the long-wave limit of the regularized long wave (RLW) equation, we study its multiple-time higher-order evolution equations. As a first result, the equations of the Korteweg-de Vries hierarchy are shown to play a crucial role in providing a secularity-free perturbation theory in the specific case of a solitary-wave solution. Then, as a conseq

G. Baym, P. Braun-Munzinger

We discuss the elementary physics of the final state Coulomb interactions in Hanbury-Brown Twiss interferometry, showing -- with explicit comparison to E877 data for $π^+π^-$ and $π^\pm p$ -- that the Coulomb corrections in the pair correlation function can be well understood in terms of simple classical physics. We connect the classical picture with descrip

S. A. Coon, B. H. J. McKellar, V. G. J. Stoks

Phenomenological Lagrangians that exhibit (broken) chiral symmetry as well as isospin violation suggest short-range charge symmetry breaking (CSB) nucleon-nucleon potentials with a $\mbox{\boldmath $σ$}_1 \!\cdot\!\mbox{\boldmath $σ$}_2$ structure. This structure could be realized by the mixing of axial-vector ($1^+$) mesons in a single-meson exchange pictur

J. Maurice Rojas

Given any polynomial system with fixed monomial term structure, we give explicit formulae for the generic number of roots with specified coordinate vanishing restrictions. For the case of affine space minus an arbitrary union of coordinate hyperplanes, these formulae are also the tightest possible upper bounds on the number of isolated roots. We also charact

Juan F. Ospina

By using Heterotic SUSY path integral, one version and generalization of an integrability theorem due to Mayer is obtained.

D. G. Barci, C. G. Bollini, L. E. Oxman, M. C. Rocca

We define, in a consistent way, non-local pseudo-differential operators acting on a space of analytic functionals. These operators include the fractional derivative case. In this context we show how to solve homogeneous and inhomogeneous equations associated with these operators. We also extend the formalism to d-dimensional space-time solving, in particular

You-Quan Li, Jian-Hui Dai

The quantum-mechanical problem of $N$ fermions with $δ$-function interaction in a one-dimensional potential well of finite depth is solved. It is shown that there exists exact wave function of Bethe-ansatz form in the case that a single particle tunnels outside of the well. The Bethe-ansatz like secular equations for the spectrum are obtained.

Marc Henneaux, Bernard Knaepen, Christiane Schomblond

The characteristic cohomology $H^k_{char}(d)$ for an arbitrary set of free $p$-form gauge fields is explicitly worked out in all form degrees $k<n-1$, where $n$ is the spacetime dimension. It is shown that this cohomology is finite-dimensional and completely generated by the forms dual to the field strengths. The gauge invariant characteristic cohomology is

I. P. Ennes, A. V. Ramallo, J. M. Sanchez de Santos

The free field representation of the osp(1|2) current algebra is analyzed. The four point conformal blocks of the theory are studied. The structure constants for the product of an arbitrary primary operator and a primary field that transforms according to the fundamental representation of osp(1|2) are explicitly calculated.

Francois Englert, Laurent Houart, Paul Windey

The coupling of a Nambu-Goto string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4μ)$, where $μ$ is the string tension. The departure from $A/4$ universality results from a string instanton which leads to a materialisation of the horizon at the quantum level.

Shinichi Deguchi, Tadahito Nakajima

We consider a Yang--Mills theory in loop space whose gauge group is a Kac--Moody group with the central extension. From this theory, we derive a local field theory constructed of Yang--Mills fields and abelian antisymmetric and symmetric tensor fields of the second rank. The Chapline--Manton coupling, that is, coupling of Yang--Mills fields and a second-rank

Eric G. Gimon, Clifford V. Johnson

A while ago, examples of N=1 vacua in D=6 were constructed as orientifolds of Type IIB string theory compactified on the K3 surface. Among the interesting features of those models was the presence of D5-branes behaving like small instantons, and the appearance of extra tensor multiplets. These are both non-perturbative phenomena from the point of view of het

Robert D. Pisarski, Michel Tytgat

At nonzero temperature, pions propagate through a thermal medium at less than the speed of light. About low temperature, this effect begins not at $\sim T^2$, but at next to leading order, $\sim T^4$. We also derive the generalization of the relation of Gell-Mann, Oakes, and Renner to nonzero temperature.

L. E. Gordon, W. Vogelsang

We study the expectations for prompt photon production rates at HERA in a fully consistent next-to-leading order (NLO) QCD analysis, taking into account the effects of experimental isolation requirements. In particular we examine the sensitivity of the isolated cross section to the photon&#39;s gluon content.

Joachim Kambor

Heavy baryon chiral perturbation theory is briefly reviewed, paying particular attention to the role of the spin 3/2 delta resonances. The concept of resonance saturation for the baryonic sector is critically discussed. Starting from a relativistic formulation of the pion-nucleon-delta system, the heavy baryon chiral lagrangian including spin 3/2 resonances

Patrik Eden, Gosta Gustafson

An improved version of the ``pop-corn&#39;&#39; model for baryon production in quark and gluon jets is presented. With a reduced number of parameters the model reproduces well both production rates for different baryon species and baryon momentum distributions. Predictions are presented for a set of baryon-antibaryon correlations.

M. Klasen

Recent NLO calculations for the photoproduction of one and two jets at HERA are compared to data from H1 and ZEUS. We discuss the physics potential of these measurements for constraining the photon structure, especially the quark density at large $x$, and study remaining hadronization and jet definition uncertainties.

Steen Hannestad, Jes Madsen

Our results for the primordial abundance of a massive Majorana tau neutrino (hep-ph/9603201) published in PRL76, 2848 (1996) were incorrect due to a trivial (but annoying) error in the numerical code. In this ERRATUM we present the corrected results.

Thorsten Feldmann

We investigate the interplay of chiral and heavy quark symmetries by using the NJL quark model. Heavy quarks with finite masses m(Q) as well as the limit m(Q) to infinity are studied. We found large corrections to the heavy mass scaling law for the pseudoscalar decay constant. The influence of external momenta on the shape parameters of the Isgur-Wise form f

Prakash Mathews, V. Ravindran

We present a systematic analysis of the polarised and unpolarised processes $e^+ ~e^- \rightarrow e^+ ~e^- X$ in the deep inelastic limit and study the effects of target photon mass (virtuality) on the photon structure functions. The effect of target photon virtuality manifests as new singly polarised structure functions and also alters the physical interpre

C. Korthals Altes, A. Michels, M. Stephanov, M. Teper

We study the detailed properties of Z_2 domain walls in the deconfined high temperature phase of the d=2+1 SU(2) gauge theory. These walls are studied both by computer simulations of the lattice theory and by one-loop perturbative calculations. The latter are carried out both in the continuum and on the lattice. We find that leading order perturbation theory

Philippe de Forcrand, Tetsuya Takaishi

We implement an adaptive step size method for the Hybrid Monte Carlo a lgorithm. The adaptive step size is given by solving a symmetric error equation. An integr ator with such an adaptive step size is reversible. Although we observe appreciable variations of the step size, the overhead of the method exceeds its benefits. We propose an explanation for this p

E. M. Aitala, E791 Collaboration

We report the result of a search for D0 - D0_bar mixing in the data from hadroproduction experiment E791 at Fermilab. We use the D* tag and semileptonic decay vertices of D0 to look for wrong-sign decays with mixing time dependence.

Jane Nachtman

The energy upgrade at LEP allows new regimes to be explored in the search for physics beyond the Standard Model. The searches for new physics using the ALEPH, DELPHI, L3, and OPAL data are described, and the results are presented.

Thibault Damour

Part of the theoretical motivation for improving the present level of testing of the equivalence principle is reviewed. The general rationale for optimizing the choice of pairs of materials to be tested is presented. One introduces a simplified rationale based on a trichotomy of competing classes of theoretical models.

Thibault Damour

The confrontation between general relativity (and its theoretically most plausible deviations) and experimental or observational results is summarized. Some discussion is devoted to the various methodologies used in confronting theory and experiment. Both weak-field (solar system) and strong-field (binary pulsar) tests are discussed in detail. A special disc

Eric Poisson

The Teukolsky equation has long been known to lead to divergent integrals when it is used to calculate the gravitational radiation emitted when a test mass falls into a black hole from infinity. Two methods have been used in the past to remove those divergent integrals. In the first, integrations by parts are carried out, and the infinite boundary terms are

Thibault Damour

A central problem in gravitational wave research is the {\it generation problem}, i.e., the problem of relating the outgoing gravitational wave field to the structure and motion of the material source. This problem has become, in recent years, of increased interest in view of the development of a worldwide network of gravitational wave detectors. We review r

Thibault Damour, David Vokrouhlicky

As gravity is a long-range force, it is {\it a priori} conceivable that the Universe&#39;s global matter distribution select a preferred rest frame for local gravitational physics. At the post-Newtonian approximation, the phenomenology of preferred-frame effects is described by two parameters, $α_1$ and $α_2$, the second of which is already very tightly cons

Kengo Maeda, Akihiro Ishibashi

We show that singularities necessarily occur when a boundary of causality violating set exists in a space-time under the physically suitable assumptions except the global causality condition in the Hawking-Penrose singularity theorems. Instead of the global causality condition, we impose some restrictions on the causality violating sets to show the occurrenc

Alpan Raval, B. L. Hu, Don Koks

In analyzing the nature of thermal radiance experienced by an accelerated observer (Unruh effect), an eternal black hole (Hawking effect) and in certain types of cosmological expansion, one of us proposed a unifying viewpoint that these can be understood as arising from the vacuum fluctuations of the quantum field being subjected to an exponential scale tran

Lian Zheng, S. Das Sarma

We calculate Coulomb scattering lifetimes of electrons in two-subband quantum wires and in double-layer quantum wells by obtaining the quasiparticle self-energy within the framework of the random-phase approximation for the dynamical dielectric function. We show that, in contrast to a single-subband quantum wire, the scattering rate in a two-subband quantum

You-Quan Li, Bin Chen

A quantum theory for mesoscopic electric circuits in accord with the discreteness of electric charges is proposed. On the basis of the theory, Schrödinger equation for the quantum LC-design and L-design is solved exactly. The uncertainty relation for electric charge and current is obtained and a minimum uncertainty state is solved. By introducing a gauge fie

N. Bulut

We present a review of the Quantum Monte Carlo results on the magnetic, charge and single-particle excitations as well as the pairing correlations of the two-dimensional Hubbard model. We are particularly interested in how these quantities are related to each other in the metallic state that forms near half-filling. These results are helpful in gaining a bet

H. G. Ballesteros, L. A. Fernandez, V. Martin-Mayor, A. Munoz Sudupe

We study the critical properties of three-dimensional O(N) models, for N=2,3,4. Parameterizing the leading corrections-to-scaling for the $η$ exponent, we obtain a reliable infinite volume extrapolation, incompatible with previous Monte Carlo values, but in agreement with $ε$-expansions. We also measure the critical exponent related with the tensorial magnet

P. A. Sreeram, P. Singha Deo

We formalize the parity effect of a multichannel ring coupled to a side branch using the tight binding model. We find that the tight binding model gives slightly different result from the continuum model. We also show that some states of the system can be nonmagnetic. In the multichannel ring coupled to a side branch, the persistent current in the ring does

A. C. C. Coolen, L. Viana

We perform a stationary state replica analysis for a layered network of Ising spin neurons, with recurrent Hebbian interactions within each layer, in combination with strictly feed-forward Hebbian interactions between successive layers. This model interpolates between the fully recurrent and symmetric attractor network studied by Amit el al, and the strictly

L. Jacak, J. Krasnyj, A. Wojs

The electronic states of a parabolic quantum dot in a magnetic field are studied with the inclusion of the spin-orbit interaction. The analitycal formulae for the ground state energy of the interacting system are derived. The spin-orbit interaction is shown to introduce new features to the far infra-red absorption spectrum, where it leads to the splitting of

G. Andrei Mezincescu, Daniel Bessis, Jean-Daniel Fournier, Giorgio Mantica

The average density of zeros for monic generalized polynomials, $P_n(z)=ϕ(z)+\sum_{k=1}^nc_kf_k(z)$, with real holomorphic $ϕ,f_k$ and real Gaussian coefficients is expressed in terms of correlation functions of the values of the polynomial and its derivative. We obtain compact expressions for both the regular component (generated by the complex roots) and t

M. Chertkov

A path integral over trajectories of $2n$ fluid particles is identified with a $2n$-th order correlation function of a passive scalar convected by $d$-dimensional short-correlated multi-scale incompressible random velocity flow. Strong intermittency of the scalar is described by means of an instanton calculus (saddle point $+$ fluctuations about it) in the p

Kenneth M. Lanzetta, Amos Yahil, Alberto Fernandez-Soto

Analysis of the deepest available images of the sky, obtained by the Hubble Space Telescope, reveals a large number of candidate high-redshift galaxies. A catalogue of 1,683 objects is presented, with estimated redshifts ranging from $z=0$ to $z>6$. The high-redshift objects are interpreted as regions of star formation associated with the progenitors of pres

J. K. Hill, W. H. Waller, R. H. Cornett, R. C. Bohlin

Far-UV (1520 ang.), U, H-alpha, and R images of the interacting Sbc spiral galaxy M51 were obtained by the Ultraviolet Imaging Telescope (UIT) and at Mt. Laguna Observatory. The mu(152)-mu(U) radial gradient of >1 mag, becoming bluer with increasing radius, is attributed primarily to a corresponding radial extinction gradient. Magnitudes in both UV bands and

F. X. Timmes, Donald D. Clayton

We calculate and discuss the chemical evolution of the isotopic silicon abundances in the interstellar medium at distances and times appropriate to the birth of the solar system. This has several objectives, some of which are related to anomalous silicon isotope ratios within presolar grains extracted from meteorites; namely: (1) What is the relative importa

Emmanuel Ullmo

We prove the discreteness of algebraic points (with respect to the Neron-Tate height) on a curve of genus greater than one embedded in his jacobian. This result was conjectured by Bogomolov. We also prove the positivity of the self intersection of the admissible dualizing sheaf.

K. Bernstein, G. Di Cecio, R. W. Haymaker

We explore vortex formation for Abelian projected SU(2) in the Polyakov gauge and compare the results with those calculated in the maximal Abelian gauge. In both gauges, a non-zero vacuum expectation value of a monopole field operator signals confinement. We find vortices in the Polyakov projection, confirming the connection between the dual superconductor o

Gad Eilam, Cai-Dian Lu, Da-Xin Zhang

We investigate the radiative dileptonic decays $B_s(B_d)\toγl^+l^-$ within the standard model. Using the constituent quark model, the branching ratios turn out to be around $5\times 10^{-9}$ for $B_s\to γμ^+μ^- $ and around $6\times 10^{-10}$ for $B_d \to γμ^+μ^- $, with slightly larger values for $B_s(B_d) \to γe^+e^- $. The differential rate as a function

Michael Mueger

Starting from a local quantum field theory with an unbroken compact symmetry group $G$ in 1+1-dimensional spacetime we construct disorder fields implementing gauge transformations on the fields (order variables) localized in a wedge region. Enlarging the local algebras by these disorder fields we obtain a nonlocal field theory, the fixpoint algebras of which

Lay Nam Chang, Chopin Soo

We present a generalization of the Frolov-Slavnov invariant regularization scheme for chiral fermion theories in curved spacetimes. local gauge symmetries of the theory, including local Lorentz invariance. The perturbative scheme works for arbitrary representations which satisfy the chiral gauge anomaly and the mixed Lorentz-gauge anomaly cancellation condit

M. Bastero-Gil, B. Brahmachari, R. N. Mohapatra

The nature of R-parity violating interactions in two classes of string inspired supersymmetric grand unified theories (SISUSY GUT), based on the gauge groups $SO(10)$ (and its subgroup $SU(2)_L\times SU(2)_R\times SU(4)_c\equiv G_{224}$) as well as $[SU(3)]^3$, are discussed and their strengths are related to the ratio of symmetry breaking scales present in

Carsten Gundlach, Jose M. Martin-Garcia

Consider any 1-parameter family of initial data such that data with parameter value p > p* form black holes, and data with p < p* do not. As p -> p* from above (&#34;critical collapse&#34;), the black hole mass scales as M ~ (p-p*)^gamma, where the critical exponent gamma is the same for all such families of initial data. So far critical collapse has been in

D. Petry, S. M. Bradbury, A. Konopelko, J. Fernandez

A detection of Gamma-rays from Mkn 421 at energies above 1 TeV is reported, based on observations made in December 1994 - May 1995 with the first two HEGRA Cherenkov telescopes. >From the image analysis, 111 excess gamma candidates are obtained from the 26 h Telescope #1 (CT1) dataset (significance 4.0 sigma) and 218 from the 41 h Telescope #2 (CT2) dataset

Martin Cederwall, Alexander von Gussich, Aleksandar Mikovic, Bengt E. W. Nilsson

In this note, we consider the reformulation of the Dirac-Born-Infeld action for a Dirichlet p-brane in Brink-Di Vecchia-Howe-Tucker form, i.e., including an independent non-propagating world-volume metric. When p>2, the action becomes non-polynomial. A closed expression is derived for p=3. For selfdual field-strengths, the DBI action is reproduced by an acti

Isabel Campos, Luis A. Fernandez, Alfonso Tarancon

We study the phase diagram of the four dimensional O(4) model with first (beta1) and second (beta2) neighbor couplings, specially in the beta2 < 0 region, where we find a line of transitions which seems to be second order. We also compute the critical exponents on this line at the point beta1 =0 (F4 lattice) by Finite Size Scaling techniques up to a lattice

Richard Hong Tuan

Using the gaussian representation for propagators (which can be proved to be exact in the infinite number of loops limit) we are able to derive the Regge behaviour for ladder graphs of $ϕ^3$ field theory in a completely new way. An analytic expression for the Regge trajectory $α(t/m^2)$ is found in terms of the mean-values of the Feynman $α$-parameters. $α(t

Carlo Angelantonj, Massimo Bianchi, Gianfranco Pradisi, Augusto Sagnotti

Starting from the type IIB string on the Z orbifold, we construct some chiral open-string vacua with N=1 supersymmetry in four dimensions. The Chan-Paton group depends on the (quantized) NS-NS antisymmetric tensor. The largest choice, SO(8)xSU(12)xU(1), has an anomalous U(1) factor whose gauge boson acquires a mass of the order of the string scale. The corre

Dror Bar-Natan

We present a formalism within which the relationship (discovered by Drinfel&#39;d) between associators (for quasi-triangular quasi-Hopf algebras) and (a variant of) the Grothendieck-Teichmuller group becomes simple and natural, leading to a simplification of Drinfel&#39;d&#39;s original work. In particular, we re-prove that rational associators exist and can

G. J. Gounaris, M. Kuroda, F. M. Renard

We propose a rather general description of residual New Physics (NP) effects on the top quark couplings. These effects are described in terms of 20 gauge invariant $dim=6$ operators involving gauge and Higgs bosons as well as quarks of the third family. We compute their implications for the $γt\bar t$, $Z t \bar t$ and $tbW$ vertices and study their observab

Joseph Polchinski

Recently Gimon and Johnson (hep-th/9604129) and Dabholkar and Park (hep-th/9604178) have constructed Type I theories on K3 orbifolds. The spectra differ from that of Type I on a smooth K3, having extra tensors. We show that the orbifold theories cannot be blown up to smooth K3&#39;s, but rather $Z_2$ orbifold singularities always remain. Douglas&#39;s recent

Hans-Juergen Matschull

This is a collection of lectures given at the University of Heidelberg, especially but not exclusively for people who want to learn something about the canonical approach to quantum gravity, which is however not included in these lectures. They are about Dirac&#39;s general method to construct a quantum theory out of a classical theory, which has to be defin

Marc-Thierry Jaekel, Serge Reynaud

We introduce observables associated with the space-time position of a quantum point defined by the intersection of two light pulses. The time observable is canonically conjugated to the energy. Conformal symmetry of massless quantum fields is used first to build the definition of these observables and then to describe their relativistic properties under fram

Astrid Lambrecht, Marc-Thierry Jaekel, Serge Reynaud

We study the radiation emitted by a cavity moving in vacuum. We give a quantitative estimate of the photon production inside the cavity as well as of the photon flux radiated from the cavity. A resonance enhancement occurs not only when the cavity length is modulated but also for a global oscillation of the cavity. For a high finesse cavity the emitted radia

Karol Przanowski

The bicovariant differential calculus on fourdimensional kappa-Poincare group and corresponding Lie-algebra like structure for any metric tensor are described. The bicovariant differential calculus on four-dimensional kappa-Weyl group and corresponding Lie-algebra like structure for any matric tensor in the reference frame in which $g_{00}=0$ are considered.

Joe Kamimoto

Consider the Bergman kernel $K^B(z)$ of the domain $\ellip = \{z \in \Comp^n ; \sum_{j=1}^n |z_j|^{2m_j}<1 \}$, where $m=(m_1,\ldots,m_n) \in \Natl^n$ and $m_n \neq 1$. Let $z^0 \in \partial \ellip$ be any weakly pseudoconvex point, $k \in \Natl$ the degenerate rank of the Levi form at $z^0$. An explicit formula for $K^B(z)$ modulo analytic functions is give

Friedemann Brandt, Marc Henneaux, André Wilch

In this paper, two things are done. (i) First, it is shown that any global symmetry of a gauge-invariant theory can be extended to the ghosts and the antifields so as to leave invariant the solution of the master-equation (before gauge fixing). (ii) Second, it is proved that the incorporation of the rigid symmetries to the solution of the master-equation thr

Jerzy Lukierski, Peter C. Stichel

We discuss quantum deformations of Lie algebra as described by the noncoassociative modification of its coalgebra structure. We consider for simplicity the quantum $D=1$ Galilei algebra with four generators: energy $H$, boost $B$, momentum $P$ and central generator $M$ (mass generator). We describe the nonprimitive coproducts for $H$ and $B$ and show that th

L. Alvarez-Gaume, M. Marino

We analyze the possible soft breaking of $N=2$ supersymmetric Yang-Mills theory with and without matter flavour preserving the analyticity properties of the Seiberg-Witten solution. We present the formalism for an arbitrary gauge group and obtain an exact expression for the effective potential. We describe in detail the onset of the confinement description a

Hideaki Aoyama, Toshiyuki Harano, Hisashi Kikuchi, Masatoshi Sato

We study the path-integral formalism in the imaginary-time to show its validity in a case with a metastable ground state. The well-known method based on the bounce solution leads to the imaginary part of the energy even for a state that is only metastable and has a simple oscillating behavior instead of decaying. Although this has been argued to be the failu

Arjun Berera

Operator definitions of diffractive parton distribution functions are given. A distinction is made between the special case of ``Regge factorization&#39;&#39; to the general case of ``diffractive factorization&#39;&#39; with explicit expressions for $F_2^{diff}(βx_{\pom}, Q^2;x_{\pom},t)$ in both cases. A calculation from a simple field theory model is prese

Haim Goldberg, Mario Gomez

Slepton mass matrices have been analyzed in an SO(10) SUSY-GUT, with soft-breaking terms generated at Planck scale. Higher dimensional operators consistent with 4-d string constructions are used in order to generate a Georgi-Jarlskog (G-J) Yukawa texture at \mgut. Radiative corrections between \mpl\ and \mgut\ generate a substantial non-universality in the $

H. Nunokawa, A. Rossi, J. W. F. Valle

We re-examine resonant massless-neutrino conversions in a dense medium induced by flavour changing neutral current (FCNC) interactions. We show how the observed $\barν_e$ energy spectra from SN1987a and the supernova $r$-process nucleosynthesis provide constraints on supersymmetric models with $R$ parity violation, which are much more stringent than those ob

E. M. Levin, A. D. Martin, M. G. Ryskin, T. Teubner

We use perturbative QCD to calculate the cross sections $σ^{L,T}$ for the diffractive production of open charm $(c\overline{c})$ from longitudinally and transversely polarised photons (of virtuality $Q^2$) incident at high energy $(\sqrt{s})$ on a proton target. We study both the $Q^2$ and $M^2$ dependence of the cross sections, where $M$ is the invariant ma

Stanislaw Mrowczynski

We study color fluctuations in the quark-gluon plasma produced at the early stage of nucleus-nucleus collision at RHIC or LHC. The fluctuating color current, which flows along the beam, can be very {\it large} due to the strong anisotropy of the parton momentum distribution. A specific fluctuation, which splits the parton system into the current filaments pa

Hyun-Chul Kim, Teruaki Watabe, Klaus Goeke

The strange vector form factors are evaluated in the range between $Q^2=0$ and $Q^2=1\ \mbox{GeV}^2$ in the framework of the SU(3) chiral quark-soliton model (or semi-bosonized SU(3) Nambu-Jona-Lasinio model). The rotational $1/N_c$ and $m_s$ corrections are taken into account up to linear order. Taking care of a proper Yukawa-tail of the kaonic cloud, we ge

Tomoko Uesugi, Masahiro Morikawa, Tetsuya Shiromizu

We quantize subcritical bubbles which are formed in the weakly first order phase transition. We find that the typical size of the thermal fluctuation reduces in the quantum-statistical physics. We estimate the typical size and the amplitude of thermal fluctuations near the critical temperature in the electroweak phase transition using quantum statistical ave

D. Comelli, J. R. Espinosa

Effective thermal masses of bosonic particles in a plasma play an important role in many different phenomena. We compute them in general supersymmetric models at leading order. The origin of different corrections is explicitly shown for the formulas to be applicable when some particles decouple. The correct treatment of Boltzmann decoupling in the presence o

Bodo Lampe

The future goals of particle physics are classified from a theorist&#39;s point of view. The prospects of mass and mixing angle determination and of the top quark and Higgs boson discovery are discussed. It is shown that the most important progress will come from LHC and NLC. These machines should be planned and developed as quickly as possible.

Wei-Shu Hou, Hsien-chung Kao

We calculate the non-universal correction to the $Zb\bar{b}$ vertex in a simple extension of the Standard Model, where a charge $+2/3$ isosinglet quark is added to the standard spectrum. Comparison is made with other solutions to $R_b$ (and $R_c$) that demand particles lighter than $M_W$.

Jisuke Kubo, Myriam Mondragon, Marek Olechowski, George Zoupanos

A natural gradual extension of the idea of Grand Unification is to attempt to relate the gauge and Yukawa couplings; Gauge-Yukawa Unification (GYU). However, within the framework of renormalizable field theories, there exists no realistic symmetry that leads to a GYU. Here we propose an approach to GYU which is based on the principle of the reduction of coup

Walter Wilcox

Formulas are developed for use in lattice studies of charged hadron polarizabilities. In particular, the valence quark different-flavor component of the charged pion polarizability is examined on a $16^{3}\times 24$ lattice at $β=6.0$ using Wilson fermions. Using the elastic limit results of Part I of this series, it is concluded that this represents a small

M. Lüscher, P. Weisz

The conservation of the isovector axial current in lattice QCD with massless Wilson quarks is studied to one-loop order of perturbation theory. Following a strategy described in a previous publication, the O($a$) counterterm required for on-shell improvement of the current is computed. We also confirm an earlier result of Wohlert for the coefficient in front

B. L. Hu

The Hawking-Unruh effect of thermal radiance from a black hole or observed by an accelerated detector is usually viewed as a geometric effect related to the existence of an event horizon. Here we propose a new viewpoint, that the detection of thermal radiance in these systems is a local, kinematic effect arising from the vacuum being subjected to a relativis

Yurii A. Neretin

We give elementary constructions for Satake-Furstenberg, Martin and Karpelevich boundaries of symmetric spaces. We also consruct some &#34;new&#34; boundaries

N. Bulut

We present Quantum Monte Carlo results on the antiferromagnetic correlations and the one-electron excitations of the doped two-dimensional Hubbard model. These results are helpful in interpreting the NMR, neutron scattering and photoemission experiments on the layered cuprates.

T. J. Newman, A. Volmer

In this brief comment we show that, contrary to previous claims [Bartelt M C and Evans J W 1993 {\it J.\ Phys.\ A} ${\bf 26}$ 2743], the asymptotic behaviour of the Kashchiev model of polynuclear growth is trivial in all spatial dimensions, and therefore lies outside the Kardar-Parisi-Zhang universality class.

Alon Drory

I use a previously introduced mapping between the continuum percolation model and the Potts fluid to derive a mean field theory of continuum percolation systems. This is done by introducing a new variational principle, the basis of which has to be taken, for now, as heuristic. The critical exponents obtained are $β= 1$, $γ= 1$ and $ν= 0.5$, which are identic

Alon Drory

The theoretical basis of continuum percolation has changed greatly since its beginning as little more than an analogy with lattice systems. Nevertheless, there is yet no comprehensive theory of this field. A basis for such a theory is provided here with the introduction of the Potts fluid, a system of interacting $s$-state spins which are free to move in the

C. Baillie, D. A. Johnston, E. Marinari, C. Naitza

We study the dynamical out-of-equilibrium behavior of a $J = \pm 1$ Ising spin glass on quenched $ϕ^{3}$ graphs. We show that magnetization and energy decay with a power law behavior, with exponents that are linear in $\frac{T}{T_{c}}$. Quenched $ϕ^{3}$ graphs turn out to be a very effective way to study numerically mean field spin glasses.