February 2000 arXiv papers — page 21

J. X. Luu, D. C. Jewitt, C. Trujillo

We report the detection of water ice in the Centaur 2060 Chiron, based on near-infrared spectra (1.0 - 2.5 micron) taken with the 3.8-meter United Kingdom Infrared Telescope (UKIRT) and the 10-meter Keck Telescope. The appearance of this ice is correlated with the recent decline in Chiron's cometary activity: the decrease in the coma cross-section allows

Takuya Matsuda, Makoto Makita, Hidekazu Fujiwara, Takizo Nagae

The history of hydrodynamic numerical simulations for accretion disks in close binary systems is reviewed, in which emphasis is placed, in particular, on the facts that spiral shock waves were numerically found in 1986 by researchers including one of the present authors and that spiral structure was discovered in IP Pegasi in 1997 by Steeghs et al. The resul

R. Indebetouw, E. G. Zweibel

We simulate fragmentation and gravitational collapse of cold, magnetized molecular clouds. We explore the nonlinear development of an instability mediated by ambipolar diffusion, in which the collapse rate is intermediate to fast gravitational collapse and slow quasistatic collapse. Initially uniform stable clouds fragment into elongated clumps with masses l

C. R. Gwinn, J. E. Reynolds, D. L. Jauncey, H. Hirabayashi

We describe measurements of the size of the Vela pulsar via scintillation, using both fits to the distribution of intensity and measurements of the modulation index. We briefly discuss systematic effects other than source size that can affect the distribution, including gain variations, self-noise, scintillation shot noise, and correlator saturation. Modulat

P. Dawson

The kappa-invariant and supersymmetric actions of D1 and D5-branes in AdS_3 x S^3 are investigated, as well as the action of a D5-brane in an AdS_5 x S^5 background. The action of a D5-brane lying totally in an AdS_3 x S^3 background is found. Some progress was made towards finding the action for the D5-brane free to move in the whole AdS_3 x S^3 x T^4 space

Pedro B. Espinoza

Contents: Introduction(3).The method of Ermakov(4).The method of Milne(7). Pinney's result(8).Lewis' results(8). The interpretation of Eliezer and Gray(14). The connection of the Ermakov invariant with Nöther's theorem(17). Possible generalizations of Ermakov's method(20). Geometrical angles and phases in Ermakov's problem(22). Applicatio

James L. Crooks, James O. Dunn, Paul H. Frampton

The origin of the highest-energy cosmic rays remains elusive. The decay of a superheavy particle (X) into an ultra-energetic neutrino which scatters from a relic (anti-)neutrino at the Z-resonance has attractive features. Given the necessary X mass of $10^{14\sim15}$ GeV, the required lifetime, $10^{15\sim16}$ y, renders model-building a serious challenge bu

Hitoshi Nishino

As generalizations of the original Volkov-Akulov action in four-dimensions, actions are found for all space-time dimensions D invariant under N non-linear realized global supersymmetries. We also give other such actions invariant under the global non-linear supersymmetry. As an interesting consequence, we find a non-linear supersymmetric Born-Infeld action f

Horatiu Nastase, Diana Vaman

We address some issues related to the construction of general Kaluza-Klein (KK) ansätze for the compactification of a supergravity (sugra) theory on a sphere $S_m$. We first reproduce various ansätze for compactification to 7d from the ansatz for the full nonlinear KK reduction of 11d sugra on $AdS_7\times S_4$. As a side result, we obtain a lagrangian formu

D. S. Freed, M. J. Hopkins

A recent paper by Moore and Witten explained that Ramond-Ramond fields in Type II superstring theory have a global meaning in K-theory. In this note we amplify and generalize some points raised in that paper. In particular, we express the coupling of the Ramond-Ramond fields to D-branes in a K-theoretic framework and show that the anomaly in this coupling ex

E. N. Archibald, J. S. Dunlop, D. H. Hughes, S. Rawlings

We present the results of the first major systematic submillimetre survey of radio galaxies spanning the redshift range 1 < z < 5. The primary aim of this work is to elucidate the star-formation history of this sub-class of elliptical galaxies by tracing the cosmological evolution of dust mass. Using SCUBA on the JCMT we have obtained 850-micron photometry o

Frank Wilczek

Unification of couplings, observation of neutrino masses in the expected range, and several other considerations confirm central implications of straightforward gauge unification based on SO(10) or a close relative and incorporating low-energy supersymmetry. The remaining outstanding consequence of this circle of ideas, yet to be observed, is nucleon instabi

Alfredo Aranda, Christopher D. Carone, Richard F. Lebed

We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U(2) theories of flavor. These models allow for solutions to the solar and atmospheric neutrino problems that do not require altering successful predictions for the charged fermions or introducing s

V. Barger, T. Han, C. -G. Zhou

We study the observability of the $\tautau$ decay mode of a Higgs boson produced in the $s$-channel at a muon collider. We find that the spin correlations of the $\tautau$ in $τ\to πν_τ, ρν_τ$ decays are discriminative between the Higgs boson signal and the Standard Model background. Observation of the predicted distinctive distribution can confirm the spin-

S. Liberati, T. Rothman, S. Sonego

We examine particle production from spherical bodies collapsing into extremal Reissner-Nordström black holes. Kruskal coordinates become ill-defined in the extremal case, but we are able to find a simple generalization of them that is good in this limit. The extension allows us to calculate the late-time worldline of the center of the collapsing star, thus e

Isa Kh. Zharekeshev, Bernhard Kramer

An application of an effective numerical algorithm for solving eigenvalue problems which arise in modelling electronic properties of quantum disordered systems is considered. We study the electron states at the localization-delocalization transition induced by a random potential in the framework of the Anderson lattice model. The computation of the interior

T. G. Kovacs, E. T. Tomboulis

We present the first measurement of the vortex free-energy order parameter at weak coupling for SU(2) in simulations employing multihistogram methods. The result shows that the excitation probability for a sufficiently thick vortex in the vacuum tends to unity. This is rigorously known to provide a necessary and sufficient condition for maintaining confineme

Geoff S. Busswell, Tom Shanks

Observations in the submillimetre waveband have recently revealed a new population of luminous, sub-mm sources. These are proposed to lie at high redshift and to be optically faint due to their high intrinsic dust obscuration. The presence of dust has been previously invoked in optical galaxy count models which assume $τ=9$ Gyr Bruzual & Charlot evolution fo

J. Lehr, M. Effenberger, H. Lenske, S. Leupold

The nucleon spectral function in infinite nuclear matter is calculated in a quantum transport theoretical approach. Exploiting the known relation between collision rates and correlation functions the spectral function is derived self-consistently. By re-inserting the spectral functions into the collision integrals the description of hard processes from the h

László Fehér, András Gábor

A family of mappings from the solution spaces of certain generalized Drinfeld-Sokolov hierarchies to the self-dual Yang-Mills system on R^{2,2} is described. This provides an extension of the well-known relationship between self-dual connections and integrable hierarchies of AKNS and Drinfeld-Sokolov type.

H. Heiselberg

Ground state energies and superfluid gaps are calculated for degenerate Fermi systems interacting via long attractive scattering lengths such as cold atomic gases, neutron and nuclear matter. In the intermediate region of densities, where the interparticle spacing $(\sim 1/k_F)$ is longer than the range of the interaction but shorter than the scattering leng

F. Krzakala, O. C. Martin

Excitations of three-dimensional spin glasses are computed numerically. We find that one can flip a finite fraction of an LxLxL lattice with an O(1) energy cost, confirming the mean field picture of a non-trivial spin overlap distribution P(q). These low energy excitations are not domain-wall-like, rather they are topologically non-trivial and they reach out

A. Deandrea, R. Gatto, M. Ladisa, G. Nardulli

The decay mode B -> rho pi is currently studied as a channel allowing, in principle, to measure without ambiguities the angle alpha of the unitarity triangle. It is also investigated by the CLEO Collaboration where a branching ratio larger than expected for the decay mode B+/- -> rho0 pi+/- has been found. We investigate the role that the B* and B(0+) resona

Shiro Kawabata

In Aharonov-Bohm (AB) cavities forming doubly connected ballistic structures, h/e AB oscillations that result from the interference among the complicated trapped paths in the cavity can be described by the framework of the semiclassical theory. We derive formulas of the correlation function C(Δϕ) of the nonaveraged magnetoconductance for chaotic and regular

L. J. Garay, J. R. Anglin, J. I. Cirac, P. Zoller

It is shown that, in dilute-gas Bose-Einstein condensates, there exist both dynamically stable and unstable configurations which, in the hydrodynamic limit, exhibit a behavior resembling that of gravitational black holes. The dynamical instabilities involve creation of quasiparticle pairs in positive and negative energy states, as in the well-known suggested

Erez M. Yahalomi

This paper has been withdrawn by the author due to similarity to Author&#39;s other paper

E. Goldobin, B. A. Malomed, A. V. Ustinov

A single magnetic fluxon moving at a high velocity in a Josephson multilayer (e.g., high-temperature superconductor such as BSCCO) can emit electromagnetic waves (Cherenkov radiation), which leads to formation of novel stable dynamic states consisting of several bunched fluxons. We find such bunched states in numerical simulation in the simplest cases of two

Hungchong Kim, Takumi Doi, Makoto Oka, Su Houng Lee

Using QCD sum rules, we compute the diagonal meson-baryon couplings, $πNN$, $ηNN$, $πΞΞ$, $ηΞΞ$, $πΣΣ$ and $ηΣΣ$, from the baryon-baryon correlation function with a meson, $i\int d^4x e^{iq\cdot x} < 0| T J_B(x) {\bar J}_B(0)|M(p)>$. The calculations are performed to leading order in $p_μ$ by considering the two separate Dirac structures, $i γ_5 γ_μp^μ$ and

F. Ferrari, H. Kleinert, I. Lazzizzera

We calculate the second topological moment < m^2 > of entanglement of two closed polymers $P_1$ and $P_2$ in a solution. The result holds approximately for a closed polymer linked to many others, which may be considered as a single very long effective polymer.

T. Miyakawa, T. Suzuki, H. Yabu

Instabilities for boson-fermion mixed condensates of trapped Alkali atoms due to the boson-fermion attractive interaction are studied using a variational method. Three regions are shown for their instabilities according to the boson-fermion interaction strength: stable, meta-stable and unstable ones. The stability condition is obtained analytically from the

Michael Bradley, Gyula Fodor, Zoltán Perjés

A global model of a slowly rotating perfect fluid ball in general relativity is presented. To second order in the rotation parameter, the junction surface is an ellipsoidal cylinder. The interior is given by a limiting case of the Wahlquist solution, and the vacuum region is not asymptotically flat. The impossibility of joining an asymptotically flat vacuum

Weimin Chen, Rostislav Matveyev

In this paper we classify symplectic Lefschetz fibrations (with empty base locus) on a four-manifold which is the product of a three-manifold with a circle. This result provides further evidence in support of the following conjecture regarding symplectic structures on such a four-manifold: if the product of a three-manifold with a circle admits a symplectic

F. Bridges, C. H. Booth, G. H. Kwei, J. J. Neumeier

We report high-resolution X-ray Absorption Near Edge Structure (XANES) measurements at the Mn K-edge as a function of temperature, for La$_{1-x}$Ca$_x$MnO$_3$ samples, with a focus mainly on the pre-edge region. Small peaks labeled A$_1$-A$_3$ are observed which corresponds to 1s-3d dipole-transitions, made weakly allowed via a hybridization of Mn 4p states

C. Balazs, J. Huston, I. Puljak

The search for the Higgs boson(s) is one of the major priorities at the upgraded Fermilab Tevatron and at the CERN Large Hadron Collider (LHC). Monte Carlo event generators (MCs) are heavily utilized to extract and interpret the Higgs signal, which depends on the details of the multiple soft-gluon emission from the initial state partons in hadronic collision

L. Accardi, S. V. Kozyrev

A new infinitesimal characterization of completely positive but not necessarily homomorphic Markov flows from a C^*-algebra to bounded operators on the boson Fock space over L^2(R) is given. Contrarily to previous characterizations, based on stochastic differential equations, this characterization is universal, i.e. valid for arbitrary Markov flows. With thi

E. Alfinito, G. Vitiello

We show that in the dissipative quantum model of brain the time-dependence of the frequencies of the electrical dipole wave quanta leads to the dynamical organization of the memories in space (i.e. to their localization in more or less diffused regions of the brain) and in time (i.e. to their longer or shorter life-time). The life-time and the localization i

M. Brillouin

Short note by Marcel Brillouin on the representation of the mass point in general relativity.

Gesche Pospiech

The discovery of quantum mechanics at the beginning of the last century led to a revolution of the physical world view. Modern experiments, made possible by new techniques on the border of the classical and the quantum regimes offer new insights and better understanding of the quantum world and have impact on technical development. Therefore it seems importa

M. Blaauboer, B. A. Malomed, G. Kurizki

&#34;Light bullets&#34; are multi-dimensional solitons which are localized in both space and time. We show that such solitons exist in two- and three-dimensional self-induced-transparency media and that they are fully stable. Our approximate analytical calculation, backed and verified by direct numerical simulations, yields the multi-dimensional generalizati

Jonathan D. Baker, Robert C. Forrey, Malgorzata Jeziorska, John D. Morgan

We have computed the Bethe logarithms for the 1 singlet S, 2 singlet S and 2 triplet S states of the helium atom to about seven figure-accuracy using a generalization of a method first developed by Charles Schwartz. We have also calculated the Bethe logarithms for the helium-like ions of Li, Be, O and S for all three states to study the 1/Z behavior of the r

C. Giusti, F. D. Pacati

The general formalism of nucleon recoil polarization in the (${\vec e},e&#39;{\vec N}N$) reaction is given. Numerical predictions are presented for the components of the outgoing proton polarization and of the polarization transfer coefficient in the specific case of the exclusive $^{16}$O(${\vec e},e&#39;{\vec p}p$)$^{14}$C knockout reaction leading to disc

Yi Li, Adrian VanDeemen, Robert Savit

In the standard minority game, each agent in the minority group receives the same payoff regardless of the size of the minority group. Of great interest for real social and biological systems are cases in which the payoffs to members of the minority group depend on the size of the minority group. This latter includes the fixed sum game. We find, remarkably,

Steve Zelditch

We give a simple proof of Tian&#39;s theorem that the Kodaira embeddings associated to a positive line bundle over a compact complex manifold are asymptotically isometric. The proof is based on the diagonal asymptotics of the Szego kernel (i.e. the orthogonal projection onto holomorphic sections). In deriving these asymptotics we use the Boutet de Monvel-Sjo

Steve Zelditch

This paper contains a very simple and general proof that eigenfunctions of quantizations of classically ergodic systems become uniformly distributed in phase space. This ergodicity property of eigenfunctions f is shown to follow from a convexity inequality for the invariant states (Af,f). This proof of ergodicity of eigenfunctions simplifies previous proofs

Steve Zelditch

Quantized contact transformations are Toeplitz operators over a contact manifold $(X,α)$ of the form $U_χ = ΠA χΠ$, where $Π: H^2(X) \to L^2(X)$ is a Szego projector, where $χ$ is a contact transformation and where $A$ is a pseudodifferential operator over $X$. They provide a flexible alternative to the Kahler quantization of symplectic maps, and encompass m

Steve Zelditch, Maciej Zworski

We prove a scattering theoretical version of the Berry-Tabor conjecture: for an almost every surface in a class of cylindrical surfaces of revolution, the large energy limit of the pair correlation measure of the quantum phase shifts is Poisson, that is, it is given by the uniform measure.

G. I. Barenblatt, A. J. Chorin, V. M. Prostokishin

Analysis of the Stockholm group data on zero-pressure-gradient boundary flows, presented in the thesis of J.~M.~Österlund ({\tt http://www.mesh.kth.se/$\sim$jens/zpg/}) is performed. The results of processing of all 70 mean velocity profiles are presented. It is demonstrated that, properly processed, these data lead to a conclusion opposite from that of the

Jan Snellman

We study the ring of all functions from the positive integers to some field. This ring, which we call \emph{the ring of number-theoretic functions}, is an inverse limit of the ``truncations&#39;&#39; Γ_n consisting of all functions f for which f(m)=0 whenever m > n. Each Γ_n is a zero-dimensional, finitely generated (K)-algebra, which may be expressed as the

Gregory J Pearlstein

Insprired by the work of C. Simpson, it is shown that every variation of graded-polarized mixed Hodge structure defined over Q gives rise to a natural Higgs field on the underlying vector bundle. In the context of Mirror Symmetry it is then shown that these Higgs fields share an intimate relationship with Quantum Cohomology.

Igor Belegradek, Vitali Kapovitch

We prove several finiteness theorems for the normal bundles to souls in nonnegatively curved manifolds. More generally, we obtain finiteness results for open Riemannian manifolds whose topology is concentrated on compact domains of ``bounded geometry&#39;&#39;.

Torsten Ehrhardt

It is well known that a Toeplitz operator is invertible if and only if its symbols admits a canonical Wiener-Hopf factorization, where the factors satisfy certain conditions. A similar result holds also for singular integral operators. More general, the dimension of the kernel and cokernel of Toeplitz or singular integral operators which are Fredholm can be

Keith Conrad

A number of constructions in function field arithmetic involve extensions from linear objects using digit expansions. This technique is described here as a method of constructing orthonormal bases in spaces of continuous functions. We illustrate several examples of orthonormal bases from this viewpoint, and we also obtain a concrete model for the continuous

Roman R. Zapatrin

For an arbitrary partially ordered set $P$ its {\em dual} $P^*$ is built as the collection of all monotone mappings $P\to\2$ where $\2=\{0,1\}$ with $0<1$. The set of mappings $P^*$ is proved to be a complete lattice with respect to the pointwise partial order. The {\em second dual} $P^{**}$ is built as the collection of all morphisms of complete lattices $P

Andrew Hassell, Steve Zelditch

We consider classes of simply connected planar domains which are isophasal, ie, have the same scattering phase $s(ł)$ for all $ł> 0$. This is a scattering-theoretic analogue of isospectral domains. Using the heat invariants and the determinant of the Laplacian, Osgood, Phillips and Sarnak showed that each isospectral class is sequentially compact in a natura

Robert G. Rieper

The automorphisms of a graph act naturally on its set of labeled imbeddings to produce its unlabeled imbeddings. The imbedding sum of a graph is a polynomial that contains useful information about a graph&#39;s labeled and unlabeled imbeddings. In particular, the polynomial enumerates the number of different ways the unlabeled imbeddings can be vertex colore

Jeongwon Ho

Counterterm actions are constructed along the ADM formalism. It is shown that the counterterm action can be intrinsically written in terms of intrinsic boundary geometry. Using the expression of counterterm action, we obtain a general form of the counterterm action available for any $d$-dimensional spherical boundary. In the description, we also derive {\it

Nelson R. F. Braga, Cresus F. L. Godinho

The role of one loop order corrections in the triplectic quantization is discussed in the case of W2 theory. This model illustrates the presence of anomalies and Wess Zumino terms in this quantization scheme where extended BRST invariance is represented in a completely anticanonical form.

L. Hoffmann, A. C. Petkou, W. Ruehl

We discuss the analytic properties of AdS scalar exchange graphs in the crossed channel. We show that the possible non-analytic terms drop out by virtue of non-trivial properties of generalized hypergeometric functions. The absence of non-analytic terms is a necessary condition for the existence of an operator product expansion for CFT amplitudes obtained fr

Sergei Klishevich

We review the interactions of massive fields of arbitrary integer spins with the constant electromagnetic field and symmetrical Einstein space in the gauge invariant framework. The problem of obtaining the gauge-invariant Lagrangians of integer spin fields in an external field is reduced to purely algebraic problem of finding a set of operators with certain

T. D. Gutierrez, R. Vogt, J. F. Gunion

The open light gluino window allows non-trivial higher twist gluino contributions to the proton wave function. Using a two-component model originally developed for charm hadroproduction, higher twist intrinsic gluino contributions to final state R-hadron formation are shown to enhance leading twist production in the forward $x_{F}$ region. We calculate R-had

K. Hagiwara, S. Ishihara, J. Kamoshita, B. A. Kniehl

We examine how accurately the general HZV couplings, with V=Z,gamma, may be determined by studying e^+e^- --> Hff-bar processes at future e^+e^- linear colliders. By using the optimal-observable method, which makes use of all available experimental information, we find out which combinations of the various HZV coupling terms may be constrained most efficient

G. Belanger, F. Boudjema, F. Donato, R. Godbole

In view of the latest LEP data we consider the effects of charginos and neutralinos on the two-photon and bbbar signatures of the Higgs at the LHC. Assuming the usual GUT inspired relation between M_1 and M_2 we show that there are only small regions with moderate tanbeta and large stop mixings that may be dangerous. Pathological models not excluded by LEP w

G. Martens, C. Traxler, U. Mosel, T. S. Biro

We study the dynamics of quarks and gluons in the Chromodielectric Model (CDM), which contains a dynamical description of confinement. Results are presented for hadronization out of an equilibrated quark--gluon plasma. It is shown that hadronization is complete and hadrons are classified within the scheme of CDM.

D. Zeppenfeld, R. Kinnunen, A. Nikitenko, E. Richter-Was

For an intermediate mass Higgs boson with SM-like couplings the LHC allows observation of a variety of decay channels in production by gluon fusion and weak boson fusion. Cross section ratios provide measurements of various ratios of Higgs couplings, with accuracies of order 15% for 100 fb^{-1} of data in each of the two LHC experiments. For Higgs masses abo

S. Dittmaier, M. Krämer, Y. Liao, M. Spira

Yukawa couplings between Higgs bosons and quarks in supersymmetric theories can be measured in the processes e^+e^- -> Q Qbar + Higgs. We have determined the cross sections of these processes in the minimal supersymmetric model including the complete set of next-to-leading order QCD corrections for all channels.

Jong-Phil Lee, Chun Liu, H. S. Song

The mass parameter of orbitally excited $Λ_c$ baryons is calculated by using QCD sum rule in the framework of heavy quark effective theory. Two kinds of interpolating current for the excited heavy baryons are introduced. It is obtained that $\barΛ=1.08^{+0.095}_{-0.104}$ GeV for the non-derivative current and $\barΛ=1.06^{+0.090}_{-0.107}$ GeV for the curren

S. Y. Choi, A. Djouadi, M. Guchait, J. Kalinowski

In most supersymmetric theories charginos, $\tildeχ^\pm_{1,2}$, belong to the class of the lightest supersymmetric particles. The chargino system can be reconstructed completely in $e^+e^-$ collider experiments: $e^+e^-\to\tildeχ_i^+ \tildeχ_j^- [i,j=1,2]$. By measuring the total cross sections and the asymmetries with polarized beams, the chargino masses an

Lars Brucher, Johannes Franzkowski

We present a new program package for calculating one-loop Feynman integrals, based on a new method avoiding Feynman parametrization and the contraction due to Passarino and Veltman. The package is calculating one-, two- and three-point functions both algebraically and numerically to all tensor cases. This program is written as a package for Maple.

Aharon Levy

The latest results on the structure of the proton and the photon as seen at HERA are reviewed while discussing the question posed in the title of the talk.

The OPAL collaboration, G Abbiendi

We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL detector, corresponds to 250 pb^-1. We present distributions of event shape variables, charged particle multiplicity and momentum, measured separately in the three

S. Kettell

The current status of rare kaon decay experiments is reviewed. New limits in the search for Lepton Flavor Violation are discussed, as are new measurements of the CKM matrix.

ZEUS Collaboration

The dependence of the photon structure on the photon virtuality, Q^2, is studied by measuring the reaction e^+p\to e^+ + {\rm jet} + {\rm jet} + {\rm X} at photon-proton centre-of-mass energies 134 < W < 223 GeV. Events have been selected in the Q^2 ranges \approx 0 GeV^2, 0.1-0.55 GeV^2, and 1.5-4.5 GeV^2, having two jets with transverse energy E_T^{jet} >

S. Kettell

This paper reviews the current status of experimental measurements of radiative kaon decays. Several experiments at BNL, CERN and FNAL have recently or will soon complete data collection; as a result, several new results are available.

The OPAL collaboration, G. Abbiendi

A search for the decay B+- to K+-K+-pi-+ was performed using data collected by the OPAL detector at LEP. These decays are strongly suppressed in the Standard Model but could occur with a higher branching ratio in supersymmetric models, especially in those with R-parity violating couplings. No evidence for a signal was observed and a 90% confidence level uppe

J. Z. Bai

BES data on $J/ψ\to γ(K^{\pm} K_S^0 π^{\mp})$ are presented. There is a strong peak due to $η(1440)/ι$, which is fitted with a Breit-Wigner amplitude with $s$-dependent widths for decays to $K^*K$, $κK$, $ηππ$ and $ρρ$; $κ$ refers to the $Kπ$ S-wave. At a $K\bar{K}π$ mass of $\sim 2040$ MeV, there is a second peak with width $\sim 400$ MeV; $J^P = 0^-$ is pr

J. Z. Bai

In a sample of 7.8 million $J/ψ$ decays collected in the Beijing Spectrometer, the process J/$ψ\toγη_c$ is observed for five different $η_c$ decay channels: $K^+K^-π^+π^-$, $π^+π^-π^+π^-$, $K^\pm K^0_S π^\mp$ (with $K^0_S\toπ^+π^-$), $ϕϕ$ (with $ϕ\to K^+K^-$) and $K^+K^-π^0$. From these signals, we determine the mass of $η_c$ to be $2976.6\pm2.9\pm1.3$ MeV.

T. P. Singh, Cenalo Vaz

We consider the quantization of a massless scalar field, using the geometric optics approximation, in the background spacetime of a collapsing spherical self-similar Vaidya star, which forms a black hole or a naked singularity. We show that the outgoing radiation flux of the quantized scalar field diverges on the Cauchy horizon. The spectrum of the produced

Marc Denecker, Victor W. Marek, Miroslaw Truszczynski

We revisit the issue of connections between two leading formalisms in nonmonotonic reasoning: autoepistemic logic and default logic. For each logic we develop a comprehensive semantic framework based on the notion of a belief pair. The set of all belief pairs together with the so called knowledge ordering forms a complete lattice. For each logic, we introduc

S. V. Kravchenko, T. M. Klapwijk

We report measurements of the zero-field resistivity in dilute 2D electron system in silicon at temperatures down to 35 mK. This extends the previously explored range of temperatures by almost an order of magnitude. On the metallic side, the resistivity near the metal-insulator transition continues to decrease with decreasing temperature and shows no low-tem

Peter Kopietz, Axel Voelker

see cond-mat/0002050

M. D. Girardeau, E. M. Wright

A mapping theorem leading to exact many-body dynamics of impenetrable bosons in one dimension reveals dark and gray soliton-like structures in a toroidal trap which is phase-imprinted. On long time scales revivals appear that are beyond the usual mean-field theory.

N. Andrei, E. Orignac

We present a one dimensional model of electrons coupled to localized moments of spin $S\ge 1$ in which magnetism and superconductivity interplay in a nontrivial manner. This model has a non-Fermi liquid ground state of the chiral spin liquid type. A non-conventional odd-frequency pairing is shown to be the dominant instability of the system, together with an

P. J. Forrester, B. Jancovici, D. S. McAnally

The structure function $S(k;β)$ for the one-dimensional one-component log-gas is the Fourier transform of the charge-charge, or equivalently the density-density, correlation function. We show that for $|k| < {\rm min} (2πρ, 2 πρβ)$, $S(k;β)$ is simply related to an analytic function $f(k;β)$ and this function satisfies the functional equation $f(k;β) = f(-2k

Anders Johansen, Didier Sornette

In January 1999, the authors published a quantitative prediction that the Nikkei index should recover from its 14 year low in January 1999 and reach $\approx 20500$ a year later. The purpose of the present paper is to evaluate the performance of this specific prediction as well as the underlying model: the forecast, performed at a time when the Nikkei was at

Eric D. Chisolm, Duane C. Wallace

A recent description of the motion of atoms in a classical monatomic system in liquid and supercooled liquid states divides the motion into two parts: oscillations within a given many-particle potential valley, and transit motion which carries the system from one many-particle valley to another. Building on this picture, we construct a model for the trajecto

Eric D. Chisolm, Brad E. Clements, Duane C. Wallace

Studies of the many-body potential surface of liquid sodium have shown that it consists of a great many intersecting nearly harmonic valleys, a large fraction of which have the same frequency spectra. This suggests that a sufficiently supercooled state of this system, remaining in a single valley, would execute nearly harmonic motion. To test this hypothesis

A. O. Sousa, S. Moss de Oliveira

We introduce fidelity into the bit-string Penna model for biological ageing and study the advantage of this fidelity when it produces a higher survival probability of the offspring due to paternal care. We attribute a lower reproduction rate to the faithful males but a higher death probability to the offspring of non-faithful males that abandon the pups to m

A. G. Green

Near to filling fraction $ν=1$, the quantum Hall ferromagnet contains multiple Skyrmion spin excitations. This multi-Skyrmion system has a tremendously rich quantum-critical structure. This is simplified when Skyrmions are pinned by disorder. We calculate the nuclear relaxation rate in this case and compare the result with experiment. We discus how such meas

Peter Fulde, Alexander Ovchinnikov

We study the magnetic field dependence of the dielectric response of large cylindrical molecules such as nanotubes. When a field-induced level crossing takes place, an applied electric field causes a linear instead of the usual quadratic Stark effect. This results in a large dielectric response. Explicit calculations are performed for doped nanotubes and a r

Peter Kopietz, Axel Voelker

We examine the time-dependent non-equilibrium current in a mesoscopic metal ring threaded by a static magnetic flux phi that is generated by a time-dependent electric field oscillating with frequency omega. We show that in quadratic order in the field there are three fundamentally different contributions to the current. (a) A time-independent contribution wh

I. Ispolatov, P. L. Krapivsky

We investigate a traffic model in which cars either move freely with quenched intrinsic velocities or belong to clusters formed behind slower cars. In each cluster, the next-to-leading car is allowed to pass and resume free motion. The model undergoes a phase transition from a disordered phase for the high passing rate to a jammed phase for the low rate. In

E. Barkai, R. Silbey, G. Zumofen

We investigate the distribution of single molecule line shape cumulants, $κ_1,κ_2,...$, in low temperature glasses based on the sudden jump, standard tunneling model. We find that the cumulants are described by Lévy stable laws, thus generalized central limit theorem is applicable for this problem.

Tatsuya Shishidou, Tamio Oguchi

Magnetic anisotropy of uranium monochalcogenides, US, USe and UTe, is studied by means of fully-relativistic spin-polarized band structure calculations within the local spin-density approximation. It is found that the size of the magnetic anisotropy is fairly large (about 10 meV/unit formula), which is comparable with experiment. This strong anisotropy is di

Ivar Martin, Alexander Balatsky

We propose here an experiment aimed to determine whether there are superconducting pairing fluctuations in the pseudogap regime of the high-$T_c$ materials. In the experimental setup, two samples above $T_c$ are brought into contact at a single point and the differential AC conductivity in the presence of a constant applied bias voltage between the samples,

Dean E. McLaughlin

The properties of old globular cluster systems (GCSs) in galaxy halos offer unique insight into the physical processes that conspire to form any generic star cluster, at any epoch. Presented here is a summary of the information obtained from (1) the specific frequencies (total populations) and spatial structures (density vs. galactocentric radius) of GCSs in

Dean E. McLaughlin

The properties of old globular cluster systems in galaxy halos are used to infer quantitative constraints on aspects of generic star (cluster) formation. First, the spatial distribution of globulars in three large galaxies, together with trends in total cluster population vs. galaxy luminosity for 97 early-type systems plus the halo of the Milky Way, imply t

Dean E. McLaughlin

A physical description of the fundamental plane of Galactic globular clusters is developed which explains all empirical trends and correlations in a large number of cluster observables and provides a small but complete set of truly independent constraints on theories of cluster formation and evolution in the Milky Way. Within the theoretical framework of sin

J. M. Moran, L. J. Greenhill, J. R. Herrnstein

Naturally occurring water vapor maser emission at 1.35 cm wavelength provides an accurate probe for the study of accretion disks around highly compact objects, thought to be black holes, in the centers of active galaxies. Because of the exceptionally fine angular resolution, 200 microarcseconds, obtainable with very long baseline interferometry, accompanied

John A. Tomsick, Philip Kaaret

We report on the X-ray spectral and timing behavior of the recurrent X-ray transient 4U 1630-47 for 51 RXTE observations made during the decay of its 1998 outburst. The observations began when the source was still relatively bright, and, during one of the early observations, a QPO with a non-Lorentzian profile occurred near 6 Hz. As the source decayed, the X

E. J. Lloyd-Davies, T. J. Ponman, D. B. Cannon

Studies of the X-ray surface brightness profiles of clusters, coupled with theoretical considerations, suggest that the breaking of self-similarity in the hot gas results from an `entropy floor&#39;, established by some heating process, which affects the structure of the intracluster gas strongly in lower mass systems. Fitting analytical models for the radia