November 2001 arXiv papers — page 11

Remo Garattini

A simple model of spacetime foam, made by two different types of wormholes in a semiclassical approximation, is taken under examination: one type is a collection of $N_{w}$ Schwarzschild wormholes, while the other one is made by Schwarzschild-Anti-de Sitter wormholes. The area quantization related to the entropy via the Bekenstein-Hawking formula hints a pos

Louis-Pierre Arguin

Topological properties of Fortuin-Kasteleyn clusters are studied on the torus. Namely, the probability that their topology yields a given subgroup of the first homology group of the torus is computed for Q=1, 2, 3 and 4. The expressions generalize those obtained by Pinson for percolation (Q=1). Numerical results are also presented for three tori of different

Daniel F. Litim, Jan M. Pawlowski

We discuss the perturbative expansion of several one-loop improved renormalisation group equations. It is shown that in general the integrated renormalisation group flows fail to reproduce perturbation theory beyond one loop.

Isabella Bierenbaum, Richard Kreckel, Dirk Kreimer

We use simple iterated one-loop graphs in massless Yukawa theory and QED to pose the following question: what are the symmetries of the residues of a graph under a permutation of places to insert subdivergences. The investigation confirms partial invariance of the residue under such permutations: the highest weight transcendental is invariant under such a pe

B. Schlittgen, T. Wettig

We extend Zirnbauer's color-flavor transformation in the fermionic sector to the case of the special unitary group. The transformation allows a certain integral over SU(N_c) color matrices to be transformed into an integral over flavor matrices which parameterize the coset space U(2N_f)/U(N_f)xU(N_f). Integrals of the type considered appear, for example,

R. A. Bertlmann, H. Narnhofer, W. Thirring

We work in the real Hilbert space H_s of hermitian Hilbert-Schmid operators and show that the entanglement witness which shows the maximal violation of a generalized Bell inequality (GBI) is a tangent functional to the convex set S subset H_s of separable states. This violation equals the euclidean distance in H_s of the entangled state to S and thus entangl

Steen Hannestad

In the early universe, neutrinos decouple from equilibrium with the electromagnetic plasma at a temperature which is only slightly higher than the temperature where electrons and positrons annihilate. Therefore neutrinos to some extent share in the entropy transfer from e^+e^- to other species, and their final temperature is slightly higher than the canonica

Cristobal Lopez, Emilio Hernandez-Garcia

We study the influence of diffusion on the scaling properties of the first order structure function, S_1, of a two-dimensional chaotically advected passive scalar with finite lifetime, i.e., with a decaying term in its evolution equation. We obtain an analytical expression for S_1 where the dependence on the diffusivity, the decaying coefficient and the stir

Paul de Medeiros, Jose Figueroa-O'Farrill, Christopher Hull, Bill Spence

A new topological conformal field theory in four Euclidean dimensions is constructed from N=4 super Yang-Mills theory by twisting the whole of the conformal group with the whole of the R-symmetry group, resulting in a theory that is conformally invariant and has two conformally invariant BRST operators. A curved space generalisation is found on any Riemannia

Roberto Casadio, Alessandro Fabbri, Lorenzo Mazzacurati

It is known that the Einstein field equations in five dimensions admit more general spherically symmetric black holes on the brane than four-dimensional general relativity. We propose two families of analytic solutions (with g_tt\not=-1/g_rr), parameterized by the ADM mass and the PPN parameter beta, which reduce to Schwarzschild for beta=1. Agreement with o

Stefan Fredenhagen, Volker Schomerus

The analysis of D-branes in coset models G/H provides a natural extension of recent studies on branes in WZW-theory and it has various interesting applications to physically relevant models. In this work we develop a reduction procedure that allows to construct the non-commutative gauge theories which govern the dynamics of branes in G/H. We obtain a large c

Bert Schroer

The previously developed algebraic lightfront holography is used in conjunction with the tensor splitting of the chiral theory on the causal horizon. In this way a universal area law for the entanglement entropy of the vacuum relative to the split (tensor factorized) vacuum is obtained. The universality of the area law is a result of the kinematical structur

Manfred Lindner, Walter Winter

We investigate what could be learned about the absolute scale of neutrino masses from comparisons among the patterns within quark and lepton mass hierarchies. First, we observe that the existing information on neutrino masses fits quite well to the unexplained, but apparently present regularities in the quark and charged lepton sectors. Second, we discuss se

E. -M. Ilgenfritz, W. Kerler, M. Muller-Preussker, H. Stuben

We study the performance of QCD simulations with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering on $10^4$ and $12^4$ lattices. In order to compare tempered with standard simulations, covariance matrices between sub-ensembles have to be formulated and evaluated using the general properties of autocorrelations o

Lubomir Gavrilov

We state two recent results concerning the linearization of integrable systems on generalised Jacobians. Then we apply this to the (complexified) spherical pendulum.

H. Kamaya, J. Silk

We study the prospects for observing H$_2$ and HD emission during the assembly of primordial molecular cloud cores. The primordial molecular cloud cores, which resemble those at the present epoch, can emerge around $1+z \sim 20$ according to recent numerical simulations. A core typically contracts to form the first generation of stars and the contracting cor

G. Mangano, G. Miele, S. Pastor, M. Peloso

The neutrino energy density of the Universe can be conveniently parametrized in terms of the so-called effective number of neutrinos, N_nu^eff. This parameter enters in several cosmological observables. In particular it is an important input in those numerical codes, like CMBFAST, which are used to study the Cosmic Microwave Background anisotropy spectrum. B

Sebastien Ragot, Jean-Michel Gillet, Pierre J. Becker

We propose a simple cluster-based method with application to calculations of Compton profile anisotropies of ice. The convergence of the method is checked with respect to Crystal95 results. Increasing both basis-set quality and cluster sizes results in a decrease of the magnitude of theoretical Compton anisotropies. The agreement with experimental data is th

I. M. Suslov

We prove the Vollhardt and Wolfle hypothesis that the irreducible vertex U_{kk'}(q) appearing in the Bethe--Salpeter equation contains a diffusion pole (with the observable diffusion coefficient D(ω,q)) in the limit k+k'\to 0. The presence of a diffusion pole in U_{kk'}(q) makes it possible to represent the quantum "collision operator" L

Karyn Le Hur, Georg Seelig

We investigate the charge fluctuations of a large quantum dot coupled to a two-dimensional electron gas via a quantum point contact following the work of Matveev. We limit our discussion to the case where exactly two channels enter the dot and we discuss the role of an anisotropy between the transmission coefficients (for these two channels) at the constrict

Wolfram Brenig, Andreas Honecker

Recent investigations of the two-dimensional spin-1/2 checkerboard lattice favor a valence bond crystal with long range quadrumer order [J.-B. Fouet et al., preprint cond-mat/0108070]. Starting from the limit of isolated quadrumers, we perform a complementary analysis of the evolution of the spectrum as a function of the inter quadrumer coupling j using both

K Ueda, H. Yamamoto, M. Naito

As-grown superconducting thin films of MgB2 were prepared by molecular beam epitaxy (MBE), and studied by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Only films prepared at temperatures between 150 and 320 deg. showed superconductivity. A best TC onset of 36 K with a sharp transition width of -1 K was obtained although the film crystallin

Ketevi A. Assamagan, Aldo Deandrea

We study the LHC sensitivity to the charged Higgs discovery in the channel H^- -> tau_L^- nu in models with a singlet neutrino in large extra dimensions. The observation of such a signal would provide a distinctive evidence for these models since in the standard two Higgs doublet model type II, H^- -> tau_L^- nu is completely suppressed.

K. Hashimoto, K. Muraki, T. Saku, Y. Hirayama

We investigate interactions between electrons and nuclear spins by using the resistance (Rxx) peak which develops near filling factor n = 2/3 as a probe. By temporarily tuning n to a different value, ntemp, with a gate, the Rxx peak is shown to relax quickly on both sides of ntemp = 1. This is due to enhanced nuclear spin relaxation by Skyrmions, and demonst

M. V. Garzelli, C. Giunti

We present the results of a Bayesian analysis of solar neutrino data in terms of nu_e->nu_{mu,tau} oscillations, independent from the Standard Solar Model predictions for the solar neutrino fluxes. We show that such a model independent analysis allows to constraint the values of the neutrino mixing parameters in limited regions around the usual SMA, LMA, LOW

Hisaki Hatanaka, Katsuhiko Ohnishi, Makoto Sakamoto, Kazunori Takenaga

It is pointed out that phase structures of gauge theories compactified on non-simply connected spaces are not trivial. As a demonstration, an SU(2) gauge model on $M^3\otimes S^1$ is studied and is shown to possess three phases: Hosotani, Higgs and coexisting phases. The critical radius and the order of the phase transitions are explicitly determined. A gene

Klebert Feitosa, Narayanan Menon

We report experiments on the equipartition of kinetic energy between grains made of two different materials in a mixture of grains vibrated in 2 dimensions. In general, the two types of grains do not attain the same granular temperature, Tg = 1/2m v^2. However, the ratio of the two temperatures is constant in the bulk of the system and independent of the vib

Dung-Hai Lee

This paper shows the existence of a duality between an unidirectional charge density wave order and a superconducting order. This duality predicts the existence of charge density wave near a superconducting vortex, and the existence of superconductivity near a charge density wave dislocation.

Abhay Ashtekar, Christopher Beetle, Jerzy Lewandowski

Geometrical structures intrinsic to non-expanding, weakly isolated and isolated horizons are analyzed and compared with structures which arise in other contexts within general relativity, e.g., at null infinity. In particular, we address in detail the issue of singling out the preferred normals to these horizons required in various applications. This work pr

Sergey V. Barabash, David Stroud

From systematic ab initio calculations of the alloy system Mg_{1-x}Al_{x}B_2, we find a strong tendency for the formation of a superstructure characterized by Al-rich layers. We also present a simple model, based on calculated energies and an estimate of the configurational entropy, which suggests that the alloy has two separate concentration regimes of phas

J. Rehacek, Z. Hradil

The invariant information introduced by Brukner and Zeilinger, Phys. Rev. Lett. 83, 3354 (1999), is reconsidered from the point of view of quantum state estimation. We show that it is directly related to the mean error of the standard reconstruction from the measurement of a complete set of mutually complementary observables. We give its generalization in te

Karl Svozil

Quantum information is radically different from classical information in that the quantum formalism (Hilbert space) makes necessary the introduction of irreducible ``nits,'' n being an arbitrary natural number (bigger than one), not just bits.

Gabriel Molina-Terriza, Juan P. Torres, Lluis Torner

We put forward schemes to prepare photons in multi-dimensional vector states of orbital angular momentum. We show realizable light distributions that yield prescribed states with finite or infinite normal modes. In particular, we show that suitable light vortex-pancakes allow the add-drop of specific vector projections. We suggest that such photons might all

S. Sivakumar

New quantal states which interpolate between the coherent states of the Heisenberg_Weyl and SU(1,1) algebras are introduced. The interpolating states are obtained as the coherent states of a closed and symmetric algebra which interpolates between the two algebras. The overcompleteness of the interpolating coherent states is established. Differential operator

P. Bertet, S. Osnaghi, P. Milman, A. Auffeves

A two-photon Fock state is prepared in a cavity sustaining a "source mode " and a "target mode", with a single circular Rydberg atom. In a third-order Raman process, the atom emits a photon in the target while scattering one photon from the source into the target. The final two-photon state is probed by measuring by Ramsey interferometry the

Holger F. Hofmann, Kenji Tsujino, Shigeki Takeuchi

Quantum teleportation requires the transmission of entangled pairs to Alice and Bob. Transmission errors modify the entangled state before the teleportation can be performed. We determine the changes in the output state caused by such transmission errors. It is shown that the errors caused by entanglement transmission are equivalent to the errors caused in a

Tien D Kieu

To explore the limitation of a class of quantum algorithms originally proposed for the Hilbert's tenth problem, we consider two further classes of mathematically non-decidable problems, those of a modified version of the Hilbert's tenth problem and of the computation of the Chaitin's $Ω$ number, which is a representation of the Gödel's Incomp

H. Atmanspacher, H. Roemer, H. Walach

The concepts of complementarity and entanglement are considered with respect to their significance in and beyond physics. A formally generalized, weak version of quantum theory, more general than ordinary quantum theory of material systems, is outlined and tentatively applied to some examples.

J. S. Laster, T. Clifford, T. D'Ottavio, A. Marusic

A Post Mortem System was developed for the Relativistic Heavy Ion Collider at Brookhaven National Laboratory to provide a playback of the collider state at the time of a beam abort, quench, or other failure event. Post Mortem data is used to provide diagnostics about the failure and to improve future stores. This data is read from hardware buffers and is wri

A. I. Smolyakov, M. Yagi, Y. Kishimoto

New unstable temperature gradient driven modes in an inhomogeneous plasma are identified. These modes represent transient $ω\simeq k_{\Vert }v_{th}^{(e,i)}$ sound oscillations in magnetized plasma that are kinetically destabilized via Landau interactions. Electron and ion sound branches are unstable for large values of the Larmor radius parameter $% k_{\bot}

T. Lahey, J. Rock, R. Sass, H. Shoaee

Since its inception in the early 1980's, the SLC control system has been driven by a highly structured memory resident real-time database. While efficient, its rigid structure and file-based sources makes it difficult to maintain and extract relevant information. The goal of transforming the sources for this database into a relational form is to enable i

R. Anni, J. N. L. Connor, C. Noli

A simple technique is described, that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving the resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Applications are made to a st

T. Haseyama, K. Asahi, J. D. Bowman, P. P. J. Delheij

The parity nonconserving spin rotation of neutrons in the 0.734-eV p-wave resonance of $^{139}La$ was measured with the neutron transmission method. Two optically polarized $^3He$ cells were used before and behind a a 5-cm long $^{139}La$ target as a polarizer and an analyzer of neutron spin. The rotation angle was carefully measured by flipping the directio

A. Cheskidov

We study a boundary layer problem for the Navier-Stokes-alpha model obtaining a generalization of the Prandtl equations conjectured to represent the averaged flow in a turbulent boundary layer. We solve the equations for the semi-infinite plate, both theoretically and numerically. The latter solutions agree with some experimental data in the turbulent bounda

Radha Balakrishnan, S. Murugesh

Starting with the general description of a moving curve, we have recently presented a unified formalism to show that three distinct space curve evolutions can be identified with a given integrable equation. Applying this to the nonlinear Schrödinger equation (NLS), we find three sets of coupled equations for the evolution of the curvature and the torsion, on

Yunbo Zeng, Huihui Dai

Based on the factorization of soliton equations into two commuting integrable x- and t-constrained flows, we derive N-soliton solutions for mKdV equation via its x- and t-constrained flows. It shows that soliton solution for soliton equations can be constructed directly from the constrained flows.

Yunbo Zeng, Yiqing Zhu, Ting Xiao, Huihui Dai

It is shown that explicit Bäcklund transformations (BTs) for the high-order constrained flows of soliton hierarchy can be constructed via their Darboux transformations and Lax representation, and these BTs are canonical transformations including Bäcklund parameter $η$ and possess a spectrality property with respect to $η$ and the 'conjugated' variabl

J. K. Lawson

This paper presents generalized momentum mappings for covariant Hamiltonian field theories. The new momentum mappings arise from a generalization of symplectic geometry to $L_VY$, the bundle of vertically adapted linear frames over the bundle of field configurations $Y$. Specifically, the generalized field momentum observables are vector-valued momentum mapp

Tadeusz Januszkiewicz, Jacek Swiatkowski

We define graph products of families of pairs of groups and study the question when two such graph products are commensurable. As an application we prove linearity of certain graph products.

Michael Harris, Stephen S. Kudla

In this note, we prove in full generality a conjecture of Jacquet concerning the nonvanishing of the triple product L-function at the central point. Let $\kay$ be a number field and let $π_i$, $i=1$, 2, 3 be cuspidal automorphic representations of $GL_2(\A)$ such that the product of their central characters is trivial. Then the central value $L(\frac12,π_1\o

Carlos Gershenson

Any system based on axioms is incomplete because the axioms cannot be proven from the system, just believed. But one system can be less-incomplete than other. Neutrosophy is less-incomplete than many other systems because it contains them. But this does not mean that it is finished, and it can always be improved. The comments presented here are an attempt to

Lubomir Gavrilov, Iliya D. Iliev

Let $(x(t),y(t))^\top$ be a solution of a Fuchsian system of order two with three singular points. The vector space of functions of the form $P(t)x(t)+Q(t)y(t)$, where $P,Q$ are real polynomials, has a natural filtration of vector spaces, according to the asymptotic behaviour of the functions at infinity. We describe a two-parameter class of Fuchsian systems

Patrick Bernard

We generalize to higher dimension results of Birkhoff and Mather on the existence of orbits wandering in regions of instability of twist maps. This generalization is strongly inspired by the one already proposed by Mather. However, its advantage is that it really contains most of the results of Birkhoff and Mather on twist maps.

Wen-Li Yang

We calculate the exchange relations of vertex operators of $U_q(\hat{sl_2})$ at level-two from its bosonic realization. The corresponding invertibility relation of type I vertex operators is also studied.

Yoshihisa Saito

We give a crystal structure on the set of all irreducible components of Lagrangian subvarieties of quiver varieties. One con show that, as a crystal, it is isomorphic to the crystal base of an irreducible highest weight representation of a quantized universal enveloping algebra.

Patrick Dehornoy, Yves Lafont

We describe new combinatorial methods for constructing an explicit free resolution of Z by ZG-modules when G is a group of fractions of a monoid where enough least common multiples exist (``locally Gaussian monoid''), and, therefore, for computing the homology of G. Our constructions apply in particular to all Artin groups of finite Coxeter type, so,

Satoru Odake

We obtain an explicit expression for the defining relation of the deformed W_N algebra, DWA(^sl_N)_{q,t}. Using this expression we can show that, in the q-->1 limit, DWA(^sl_N)_{q,t} with t=e^{-2πi/N}q^{(k+N)/N} reduces to the sl_N-version of the Lepowsky-Wilson's Z-algebra of level k, ZA(^sl_N)_k. In other words DWA(^sl_N)_{q,t} with t=e^{-2πi/N}q^{(k+N

Pavel Etingof, Shlomo Gelaki

Recall (math.QA/9812151) that the exponent of a finite-dimensional complex Hopf algebra H is the order of the Drinfeld element u of the Drinfeld double D(H) of H. Recall also that while this order may be infinite, the eigenvalues of u are always roots of unity (math.QA/9812151, Theorem 4.8); i.e., some power of u is always unipotent. We are thus naturally le

James Bjorken

The old idea that the photon is a Goldstone boson emergent from a spontaneously broken theory of interacting fermions is revisited. It is conjectured that the gauge-potential condensate has a vacuum expectation value which is very large, perhaps the GUT/Planck momentum scale, but that the magnitude of the effective potential which generates it is very small,

P. Grange, S. Salmons, E. Werner

Critical behaviour of the 2D scalar field theory in the LC framework is reviewed. The notion of dynamical zero modes is introduced and shown to lead to a non trivial covariant dispersion relation only for Continuous LC Quantization (CLCQ). The critical exponent $η$ is found to be governed by the behaviour of the infinite volume limit under conformal transfor

Jing-Bo Chen, Han-Ying Guo, Ke Wu

We present a discrete total variation calculus in Hamiltonian formalism in this paper. Using this discrete variation calculus and generating functions for the flows of Hamiltonian systems, we derive two-step symplectic-energy integrators of any finite order for Hamiltonian systems from a variational perspective. The relationship between symplectic integrator

Wei-Min Sun, Xiang-Song Chen, Fan Wang

In this paper we investigated the problem of the existence of invariant meaures on the local gauge group. We prove that it is impossible to define a {\it finite} translationally invariant measure on the local gauge group $C^{\infty}({\bf R}^n,G)$(where $G$ is an arbitrary matrix Lie group).

Mirjam Cvetic, Gary Shiu, Angel M. Uranga

We summarize some recent progress in constructing four-dimensional supersymmetric chiral models from Type II orientifolds. We present the construction a supersymmetric Standard-like Model and a supersymmetric GUT model to illustrate the new features of this approach and its connection to M theory on compact, singular G_2 holonomy spaces. The Standard-like mo

A. J. M. Medved

In this paper, we investigate the near-extremal thermodynamics of the Reissner-Nordstrom (RN) black hole. Our methodology is based on a duality that exists between the near-horizon geometry of the near-extremal RN sector and Jackiw-Teitelboim (JT) theory. First, the described correspondence is reviewed at the classical level. Next, we consider first-order pe

Leonard Gamberg, Gary R. Goldstein

Exploiting the phenomenological symmetry of the $J^{PC}=1^{+-}$ light axial vector mesons and using pole dominance, we calculate the flavor contributions to the nucleon tensor charge.

Antonio L. Maroto

We consider the amplification of electromagnetic quantum vacuum fluctuations induced by the presence of metric perturbations at the end of inflation. We obtain the amplitude of the corresponding magnetic fields on super-Hubble scales and compare it with the requirements of the galactic dynamo mechanism for different values of the spectral index. Finally we d

Alakabha Datta, C. S. Kim, David London

In this talk we show that, unlike other pure $b\to d$ penguin processes, the decay $\bs(t)\toϕ\ks$ is dominated by a single amplitude, that of the internal $t$-quark. Thus, the indirect CP asymmetry in this decay probes $\sin 2β$. This cancellation holds for most part of the parameter space and error on $\sin 2β$ is less than 10%. By measuring the direct CP

H. Satz

The aim of high energy nuclear collisions is to study the transition from hadronic matter to a plasma of deconfined quarks and gluons. I review the basic questions of this search and summarize recent theoretical developments in the field.

J. Pestieau, C. Smith

QED gauge invariance, when combined with analyticity, leads to constraints on the low energy end of the emitted photon spectra. This is known as Low's theorem. It is shown that the Ore-Powell result, as well as further developments for the orthopositronium differential decay rate, are in contradiction with Low's theorem, i.e. that their predicted sof

I. Scimemi, E. Pallante, A. Pich

We overview the detailed analysis of epsilon'/epsilon within the Standard Model, presented in ref. 1. When all sources of large logarithms are considered, both at short and long distances, it is possible to perform a reliable Standard Model estimate of epsilon'/epsilon. The strong S-wave rescattering of the final pions has an important impact on this

K. Redlich, A. Tounsi

The canonical statistical model analysis of strange and multistrange hadron production in central A-A relative to p-p/p-A collisions is presented over the energy range from $\sqrt s=8.73$ GeV up to $\sqrt s =130$ GeV. It is shown that the relative enhancement of strange particle yields from p-p/p-A to A-A collisions substantially increases with decreasing co

A. Krassnigg, Hans-Christian Pauli

Starting from a one-body front-form equation with Lepage-Brodsky spinors we show, with a fair amount of new technology, how an integral equation in standard momentum space with Bjorken-Drell spinors can be obtained. The integral equation decouples for singlets and triplets.

P. Jankowski, M. Krawczyk, A. De Roeck

Heavy quark production is studied at the high energy linear e^+e^- collider (LC) TESLA both in its nominal and Photon Collider (PC) mode. Leading order cross-sections are calculated for the production of heavy quarks, e^+e^- -> e^+e^- Q\bar{Q}X, at high transverse momenta. The sensitivity of this process to the gluon content in the photon is studied.

J. F. de Trocóniz, F. J. Ynduráin

We present a summary of the results of two recent precise calculations of the muon anomalous magnetic moment ($g_μ-2$) and the electromagnetic coupling on the $Z$ ($\barα_{\rm Q.E.D.}(M^2_{Z})$). The main sources of uncertainty are underlined.

H. G. Wu

In order to interface the DESY fieldbus adapter, SEDAC (SErial Data Acquisition and Control system), a full duplex device driver was developed for the Windows NT, Linux, VxWorks, and Solaris operating systems. Detailed driver development issues as well as a common user interface will be presented, along with a comparison of the device drivers among the diffe

T. Gehrmann, E. Remiddi

The two-dimensional harmonic polylogarithms $\G(\vec{a}(z);y)$, a generalization of the harmonic polylogarithms, themselves a generalization of Nielsen's polylogarithms, appear in analytic calculations of multi-loop radiative corrections in quantum field theory. We present an algorithm for the numerical evaluation of two-dimensional harmonic polylogarith

E. M. Leikin, E. V. Balandina, N. P. Yudin

The results of linear regresion of differential cross sections, $Σ$- and $T$-asymmetries of $η$-photoproduction on protons in energy region from threshold up to 1 GeV are presented. Serious contradictions between angular distributions measured in different laboratories are revealed. The energy dependance of regression coefficients may be due to transition fr

J. Zhao, C. H. Wang, X. C. Kong, G. Lei

Recently the Chinese Academy of Sciences has chosen BEPCII as the future development of the BEPC, i.e. upgrade of both the machine and detector. The luminosity of the machine is expected to increase to 1.0x1033cm-2s-1. The project will be started at the beginning of 2002 and finished with in 3-4 years. The BEPC control system was built in 1987 and upgraded i

L. Dittmann, T. Heinzl, A. Wipf

We review some approaches to describe confinement in terms of effective (model) field theories. After a brief discussion of the dual Abelian Higgs model, we concentrate on a lattice analysis of the Faddeev-Niemi effective action conjectured to describe the low-lying excitations of SU(2) gluodynamics. We generalize the effective action such that it contains a

Yoshio Kikukawa, Yoichi Nakayama, Hiroshi Suzuki

Based on the Ginsparg-Wilson relation, a gauge invariant formulation of electroweak SU(2)xU(1) gauge theory on the lattice is considered. If the hypercharge gauge coupling is turned off in the vacuum sector of the U(1) gauge fields, the theory consists of four left-handed SU(2) doublets and it is possible, as in vector-like theories, to make the fermion meas

Yoshio Kikukawa

Theoretical issues of exact chiral symmetry on the lattice are discussed and related recent works are reviewed. For chiral theories, the construction with exact gauge invariance is reconsidered from the point of view of domain wall fermion. The issue in the construction of electroweak theory is also discussed. For vector-like theories, we discuss unitarity (

T. Kaneko

Recent developments in lattice QCD calculations of the light hadron spectrum and quark masses are reviewed.

Igor Kachaev, for VES Collaboration

The results on partial wave analysis of 3pi system produced at beam momentum 36.6 GeV/c on beryllium target are presented. New method of amplitude analysis is suggested -- extraction of largest eigenvalue of density matrix. Exotic wave with JPC = 1-+ in rho pi system is studied in four t' regions. No narrow object around M = 1.6 GeV is found. Unusually s

Yasushi Mino, Hiroyuki Nakano, Misao Sasaki

Covariant structure of the self-force of a particle in a general curved background has been made clear in the cases of scalar [Quinn], electromagnetic [DeWittBrehme], and gravitational charges [QuinnWald]. Namely, what we need is the part of the self-field that is non-vanishing off and within the past light-cone of particle's location, the so-called tail

P. Crawford, I. Tereno

To resolve some unphysical interpretations related to velocity measurements by static observers, we discuss the use of generalized observer sets, give a prescription for defining the speed of test particles relative to those observers and show that, for any locally inertial frame, the speed of a freely falling material particle is always less than the speed

Robert J. Low

We examine the holography bound suggested by Bousso in his covariant entropy conjecture, and argue that it is violated because his notion of light sheet is too generous. We suggest its replacement by a weaker bound.

B. J. Lee, T. H. Lee

As a candidate for dark matter in galaxies, we study an SU(3) triplet of complex scalar fields which are non-minimally coupled to gravity. In the spherically symmetric static spacetime where the flat rotational velocity curves of stars in galaxies can be explained, we find simple solutions of scalar fields with SU(3) global symmetry broken to U(1) X U(1), in

J. Luo, Y. X. Nie, Y. Z. Zhang, Z. B. Zhou

The differential acceleration between a rotating mechanical gyroscope and a non-rotating one is directly measured by using a double free-fall interferometer, and no apparent differential acceleration has been observed at the relative level of 2x10{-6}. It means that the equivalence principle is still valid for rotating extended bodies, i.e., the spin-gravity

M. C. Bento, O. Bertolami, N. C. Santos

We discuss the dynamics of a quintessence model involving two coupled scalar fields. The model presents two types of solutions, namely solutions that correspond to eternal and transient acceleration of the universe. In both cases, we obtain values for the cosmological parameters that satisfy current observational bounds as well as the nucleosynthesis constra

D. Stauffer

The Sznajd model, where two people having the same opinion can convince their neighbours on the square lattice, is modified in the sense of Deffuant et al and Hegselmann, that only neighbours of similar opinions can be convinced. Then consensus is easy for the competition of up to three opinions but difficult for four and more opinions.

A. M. Dikande

By examining the bound-state spectra of transverse fluctuations about one-dimensional, spatially localized dark and bright soliton wavetrains of the Gross-Pitaevskii equation, it is established that the low-temperature ground states of repulsive and attractive quasi-one-dimensional Bose-Einstein condensates are degenerate. In the one-soliton limit, both grou

Prashant Sharma, Claudio Chamon

We show that Feldman and Gefen's comment revolves around a trivial issue - the relative magnitudes for the two crossover scales in the problem.

Y. B. Band, B. Malomed, M. Trippenbach

A simple model of an atomic Bose-Einstein condensate in a box whose size varies with time is studied to determine the nature of adiabaticity in the nonlinear dynamics obtained within the Gross-Pitaevskii equation (the nonlinear Schrodinger equation). Analytical and numerical methods are used to determine the nature of adiabaticity in this nonlinear quantum s

T. Kleimann, M. Sassetti, B. Kramer

The temperature dependence of Coulomb blockade peaks of a one dimensional quantum dot is calculated. The Coulomb interaction is treated microscopically using the Luttinger liquid model. The electron interaction is assumed to be non-homogeneous with a maximum strength near the quantum dot. The conductance peaks show non-analytic power law behaviour induced by

T. Kleimann, M. Sassetti, G. Cuniberti, B. Kramer

We examine the effects of long-range interactions in a quantum wire with two impurities. We employ the bosonization technique and derive an effective action for the system. The effect of the long-range interaction on the charging energy and spectral properties of the island formed by the impurities and the linear transport is discussed.

Federico A. Gorelli, Mario Santoro, Lorenzo Ulivi, Michael Hanfland

Results of X-ray diffraction experiments on solid oxygen at low temperature and at pressures up to 10 GPa are presented.A careful sample preparation and annealing around 240 K allowed to obtain very good diffraction patterns in the orthorhombic delta-phase. This phase is stable at low temperature, in contrast to some recent data [Y. Akahama et al., Phys. Rev

Dima E. Feldman, Yuval Gefen

This is a Comment to the paper by Sharma and Chamon in Phys. Rev. Lett. 87 (2001) 096401 (cond-mat/0011025). We show that the prediction of the universal charge pumped per cycle in the fast limit for attractive electron-electron interaction is invalid. We also prove the quantization of the pumped charge for repulsive interaction in the limit of adiabatic pum

Seiji Yunoki

Magnetization processes of the spin-1/2 antiferromagnetic $XXZ$ model in two and three spatial dimensions are studied using quantum Monte Carlo method based on stochastic series expansions. Recently developed operator-loop algorithm enables us to show a clear evidence of the first-order phase transition in the presence of an external magnetic field. Phase di

C. Schlichenmaier, I. Varga, T. Meier, P. Thomas

On the basis of a tight-binding model for a strongly disordered semiconductor with correlated conduction- and valence band disorder a new coherent dynamical intra-band effect is analyzed. For systems that are excited by two, specially designed ultrashort light-pulse sequences delayed by tau relatively to each other echo-like phenomena are predicted to occur.

N. P. Duong, E. Brueck, P. E. Brommer, A. de Visser

We report the observation of a field-induced transformation from the easy-plane antiferromagnetic structure to the easy-axis ferrimagnetic structure in a single crystal of TbFe_4.4Al_7.6 (tetragonal ThMn_12 structure) at 5 K. Such a field-induced, irreversible transition has been identified for the first time. This transition is accompanied by a giant orthor