April 2001 arXiv papers — page 14

Tracy L. Beck, M. Simon

We present the historical light curve of T Tau derived from photographic plates in the Harvard College Observatory archives. We find that the optical light of T Tau varied by 2-3 (or more) magnitudes on time scales as short as a month prior to ~1917, consistent with the results of Lozinskii (1949). Extreme light fluctuations of greater than 2 magnitudes abru

A. H. Corsico, O. G. Benvenuto

We present a finite difference code intended for computing linear, adiabatic, nonradial pulsations of spherical stars. This code is based on a general Newton - Raphson technique in order to handle the relaxation of the eigenvalue (square of the eigenfrequency) of the modes and their corresponding eigenfunctions. This code has been tested computing the pulsat

N. Andronov, M. Pinsonneault, A. Sills

We apply the angular momentum loss rates inferred from open cluster stars to the evolution of cataclysmic variables (CVs). We show that the angular momentum prescriptions used in earlier CV studies are inconsistent with the measured rotation data in open clusters. The timescale for angular momentum loss above the fully convective boundary is ~ 2 orders of ma

G. G. Pavlov, O. Y. Kargaltsev, D. Sanwal, G. P. Garmire

The observations of the pulsar-wind nebula (PWN) around the Vela pulsar with the Advanced CCD Imaging Spectrometer aboard the Chandra X-ray Observatory, taken on 2000 April 30 and November 30, reveal its complex morphology reminiscent of that of the Crab PWN. Comparison of the two observations shows changes up to 30% in the surface brightness of the PWN feat

Smita Mathur, Joanna Kuraszkiewicz, Bozena Czerny

Mathur (2000) has proposed that the narrow line Seyfert 1 galaxies (NLS1s) are likely to be the active galaxies in early stage of evolution. To test this hypothesis, we have calculated the black hole (BH) masses and the host galaxy bulge masses for a sample of NLS1s. We find that the mean BH to bulge mass ratio of NLS1s is significantly smaller than that for

Travis S. Barman, Peter H. Hauschildt, France Allard

We have modeled irradiated planets located near a dM5 and a G2 primary star. The impinging radiation field was explicitly included in the solution of the radiative transfer equation and in the computation of the atmospheric structure. We find that large errors in both the thermal and reflected flux will result from models which do not include the impinging r

P. G. van Dokkum, S. A. Stanford, B. P. Holden, P. R. Eisenhardt

We present a study of the galaxy population in the cluster RXJ0848+4453 at z=1.27, using deep HST NICMOS and WFPC2 images. We morphologically classify all galaxies to K_s=20.6 that are covered by the HST imaging, and determine photometric redshifts using deep ground based BRIzJK_s photometry. Of 22 likely cluster members with morphological classifications, e

Doron Chelouche, Hagai Netzer

We present calculations of the dynamics of highly ionized gas clouds that are confined by external pressure, and are ionized by AGN continuum. We focus on the gas that is seen in absorption in the X-ray spectrum of many AGN and show that such gas can reach hydrostatic equilibrium under various conditions. The principal conclusion is that the clouds can be ac

Jongsoo Kim, Dongsu Ryu, T. W. Jones

We investigate the effects of rotation on the evolution of the Parker instability in an exponentially-stratified and uniformly-rotating magnetized gas disk by carrying out three-dimensional numerical simulations with an isothermal magnetohydrodynamic code. The instability has been initialized by random velocity perturbations. In the linear stage, the evoluti

Peter H. Hauschildt, David K. Lowenthal, E. Baron

We describe two parallel algorithms for line opacity calculations based on a local file and on a global file approach. The performance and scalability of both approaches is discussed for different test cases and very different parallel computing systems. The results show that a global file approach is more efficient on high-performance parallel supercomputer

I. Dominguez, P. Hoeflich, O. Straniero

Detailed calculations for the stellar evolution, explosion and light curves have been performed to quantify the influence of the main sequence mass M(MS) and the metallicity of the progenitor on the structure of the exploding WD which are thought to be the progenitors of SNe Ia. In particular,we study the effects of progenitors on the brightness decline rela

Kazuhiro Yamamoto, Toshifumi Futamase

A possible method to reconstruct the cosmic equation of state using strong gravitational lensing systems is proposed. The feasibility of the method is investigated by carrying out the reconstruction on the basis of a simple Monte-Carlo simulation. We show that the method can work and that the cosmic equation of state $w(z)$ can be determined within errors of

Ryoichi Yamamoto

A new method is presented for mesoscopic simulations of particle dispersions in nematic liquid crystal solvents. It allows efficient first-principle simulations of the dispersions involving many particles with many-body interactions mediated by the solvents. A simple demonstration is shown for the aggregation process of a two dimentional dispersion.

Richard E. Livine, Daniele Oriti

We study a generalized action for gravity as a constrained BF theory, and its relationship with the Plebanski action. We analyse the discretization of the constraints and the spin foam quantization of the theory, showing that it leads naturally to the Barrett-Crane spin foam model for quantum gravity. Our analysis holds true in both the Euclidean and Lorentz

Takashi Hamana

Gravitational lensing causes a correlation between a population of foreground large-scale structures and the observed number density of the background distant galaxies as a consequence of the flux magnification and the lensing area distortion. This correlation has not been taken into account in calculations of the theoretical predictions of the cosmic shear

Debajyoti Choudhury, S. Rai Choudhury, Abhinav Gupta, Namit Mahajan

Recently proposed stabilization mechanism of the Randall-Sundrum metric gives rise to a scalar radion, which couples universally to matter with a weak interaction ($\simeq 1$ TeV) scale. Demanding that gauge boson scattering as described by the effective low enerrgy theory be unitary upto a given scale leads to significant constraints on the mass of such a r

V. Dzhunushaliev

A geometrical interpretation of Grassmannian anticommuting coordinates is given. They are taken to represent an indefiniteness inherent in every spacetime point on the level of the spacetime foam. This indeterminacy is connected with the fact that in quantum gravity in some approximation we do not know the following information : are two points connected by

T. A. Bouma

Given an automorphism and an anti-automorphism of a semigroup of a Geometric Algebra, then for each element of the semigroup a (generalized) projection operator exists that is defined on the entire Geometric Algebra. A single fundamental theorem holds for all (generalized) projection operators. This theorem makes previous projection operator formulas equival

Desmond Sheiham

Almkvist proved that for a commutative ring A the characteristic polynomial of an endomorphism α:P \to P of a finitely generated projective A-module determines (P,α) up to extensions. For a non-commutative ring A the generalized characteristic polynomial of an endomophism α: P \to P of a finitely generated projective A-module is defined to be the Whitehead t

Martin Guest

This is a survey article on Morse theory based on lectures to graduate students and advanced undergraduates. After a brief review of standard material, mostly without proofs, the Morse theory of complex Grassmannian manifolds is worked out in detail. In contrast to standard treatments, gradient flow lines and their structure are emphasized. This leads to a c

Jun Li

The introduction is modified in the revised version. Also, many typos and errors were corrected. Let $W\to C$ be degeneration of smooth varieties so that the special fiber has normal crossing singularity. In this paper, we first constructed the stack of expanded degenerations of $W$. We then constructed the moduli space of stable morphisms to this stack, whi

Miloslav Znojil

Harmonic oscillators with a centrifugal spike are analysed, via a non-Hermitian regularization, within a complexified SUSY quantum mechanics. The formalism enables us to construct the factorized creation and annihilation operators. We show how the real though, generically, non-equidistant spectrum complies with the current SUSY-type isospectrality and degene

Paul H. Frampton

By use of the AdS/CFT correspondence on orbifolds, models are derived which can contain the standard model of particle phenomenology. It will be assumed that the theory becomes conformally invariant at a renormalization-group fixed-point in the TeV region.

C. Giunti

It is shown that Lorentz invariance implies that in general flavor neutrinos in oscillation experiments are superpositions of massive neutrinos with different energies and different momenta. It is also shown that for each process in which neutrinos are produced there is either a Lorentz frame in which all massive neutrinos have the same energy or a Lorentz f

G. E. Volovik

Quantum liquids, in which an effective Lorentzian metric and thus some kind of gravity gradually arise in the low-energy corner, are the objects where the problems related to the quantum vacuum can be investigated in detail. In particular, they provide the possible solution of the cosmological constant problem: why the vacuum energy is by 120 orders of magni

Paul S. Wesson, Hongya Liu

We present technical results which extend previous work and show that the cosmological constant of general relativity is an artefact of the reduction to 4D of 5D Kaluza-Klein theory (or 10D superstrings and 11D supergravity). We argue that the distinction between matter and vacuum is artificial in the context of ND field theory. The concept of a cosmological

Vesselin Petkov

It appears to follow from the Reissner-Nordstrom solution of Einstein's equations that the charge of a body reduces its gravitational field. In a recent note Hushwater offered an explanation of this apparent paradox. His explanation, however, raises more questions than solves since it implies that the active gravitational mass of a charged body is distan

Oded Millo, David Katz, YunWei Cao, Uri Banin

Current imaging scanning tunneling microscopy is used to observe the electronic wavefunctions in InAs/ZnSe core/shell nanocrystals. Images taken at a bias corresponding to the s conduction band state show that it is localized in the central core region, while images at higher bias probing the p state reveal that it extends to the shell. This is supported by

You-Yu Chen, Zhen Ye

This paper presents a theoretical analysis of the recently reported observation of acoustic stop bands in two-dimensional scattering arrays (Robertson and Rudy, J. Acoust. Soc. Am. {\bf 104}, 694, 1998). A self-consistent wave scattering theory, incorporating all orders of multiple scattering, is used to obtain the wave transmission. The band structures for

J. P. Huang, Jones T. K. Wan, C. K. Lo, K. W. Yu

When a suspension consisting of dielectric particles having nonlinear characteristics is subjected to a sinusoidal (ac) field, the electrical response will in general consist of ac fields at frequencies of the higher-order harmonics. These ac responses will also be anisotropic. In this work, a self-consistent formalism has been employed to compute the induce

D. A. Garanin, D. V. Dmitriev, P. Fulde

Thermodynamic properties of any quantum spin system can be described by the formally exact, although in general intractable, effective classical Hamilton function \cal H. Here we obtain an explicit form of \cal H which applies at T << J S^2, where J is the exchange and S in the spin value, and incorporates quantum effects at the level of the spin-wave theory

David A. Smith, Andrew S. Wilson

We report on a recent Chandra ACIS-S observation of the Circinus galaxy. These observations confirm that the nuclear spectrum results from reflection of a hard X-ray continuum by ``neutral&#39;&#39; matter. The nuclear X-ray emission is extended by \sim 60 pc in the general direction of the optical ``ionization cone&#39;&#39;. An image in the Fe Kαline has b

R. Foot, Z. K. Silagadze

Mirror matter is predicted to exist if parity is an unbroken symmetry of nature. Currently, there is a large amount of evidence that mirror matter actually exists coming from astrophysics and particle physics. One of the most fascinating (but speculative) possibilities is that there is a significant abundance of mirror matter within our solar system. If the

J. H. P. Wu, A. Balbi, J. Borrill, P. G. Ferreira

Gaussianity of the cosmological perturbations in the universe is one of the key predictions of standard inflation, but it is violated by other models of structure formation such as topological defects. We present the first test of the Gaussianity of the cosmic microwave background (CMB) on sub-degree angular scales, where deviations from Gaussianity are most

Jiun-Huei Proty Wu

We investigate linear matter density perturbations in models of structure formation with causal seeds. Under the fluid approximation, we obtain the analytic solutions using Green-function technique. Some incorrect solutions in the literature are corrected here. Based on this, we analytically prove that the matter density perturbations today are independent o

Jiun-Huei Proty Wu

Searching for and charactering the non-Gaussianity (NG) of a given field has been a vital task in many fields of science, because we expect the consequences of different physical processes to carry different statistical properties. Here we propose a new general method of extracting non-Gaussian features in a given field, and then use simulated cosmic microwa

Jiun-Huei Proty Wu

We use the presently observed number density of large X-ray clusters and linear mass power spectra to constrain the shape parameter ($Γ$), the spectral index ($n$), the amplitude of matter density perturbations on the scale of $8 h^{-1}$Mpc ($σ_8$), and the redshift distortion parameter ($β$). The non-spherical-collapse model as an improvement to the Press-S

Jiun-Huei Proty Wu

We propose a new general method of extracting non-Gaussian features in a given field. It sets the mean of the field to zero and renormalizes its Fourier (or multipole) power to white noise, while keeping the phase information unchanged. Using simulated cosmic microwave background (CMB) as an example, we demonstrate the power of this method under many challen

V. Krasnoselskikh, O. Podladchikova, B. Lefebvre, N. Vilmer

Recent observations of Krucker & Benz (1998) give strong support to Parker&#39;s hypothesis (Parker 1988) that small scale dissipative events make the main contribution to quiet Sun coronal heating. They also showed that these small scale events are associated not only with the magnetic network, but also with the cell interiors (Benz & Krucker, 1998). Taking

B. C. Allanach

SOFTSUSY is a program which accurately calculates the spectrum of superparticles in the CP-conserving Minimal Supersymmetric Standard Model (MSSM), with a full flavour mixing structure. The program solves the renormalisation group equations with theoretical constraints on soft supersymmetry breaking terms provided by the user. Weak-scale gauge coupling and f

Nahomi Kan, Takuya Maki, Kiyoshi Shiraishi

A point particle treatment to the statistical mechanics of BPS black holes in Einstein-Maxwell-dilaton theory is developed. Because of the absence of the static potential, the canonical partition function for $N$ BPS black holes can be expressed by the volume of the moduli space for them. We estimate the equation of state for a classical gas of BPS black hol

Sohrab Rahvar

In general relativistic framework of the large scale structure formation theory in the universe, we investigate the relation between density contrast and peculiar velocity in the Newtonian gauge. According to the gauge-invariant property of the energy-momentum tensor in the Newtonian gauge, we consider the perturbation of velocity in the energy-momentum tens

S. W. Ham, J. Kim, S. K. Oh, D. Son

The phenomenology of the explicit CP violation in the Higgs sector of the next-to-minimal supersymmetric standard model (NMSSM) is investigated, with emphasis on the charged Higgs boson. The radiative corrections due to both quarks and scalar-quarks of the third generation are taken into account, and the negative result of the search for the Higgs bosons at

Suresh Govindarajan, T. Jayaraman

We construct boundary conditions in the gauged linear sigma model for B-type D-branes on Calabi-Yau manifolds that correspond to coherent sheaves given by the cohomology of a monad. This necessarily involves the introduction of boundary fields, and in particular, boundary fermions. The large-volume monodromy for these D-brane configurations is implemented by

S. C. Badescu, S. C. Ying, T. Ala-Nissila

We consider a quantum system coupled to a dissipative background with many degrees of freedom using the Monte Carlo Wave Function method. Instead of dealing with a density matrix which can be very high-dimensional, the method consists of integrating a stochastic Schrodinger equation with a non-hermitian damping term in the evolution operator, and with random

H. J. Carmichael

We review studies of the fluctuations of light made accessible by the invention of the laser and the strong interactions realized in cavity QED experiments. Photon antibunching advocating the discrete (particles), is contrasted with amplitude squeezing which speaks of the continuous (waves). The tension between particles and waves is demonstrated by a recent

Patrick Krejcik

The parameters for a 30 GeV test beam are outlined for use with an undulator in the FFTB tunnel where the LCLS will eventually be housed. It is proposed to use the SLAC linac and damping rings in their present mode of operation for PEP II injection, where 30 GeV beams are also delivered at 10 Hz to the FFTB. High peak currents are obtained with the addition

Lawrence Pack, Ram Anand Puri

We present a general method for obtaining a lower bound for the ground state entropy density of the Ising Model with nearest neighbor interactions. Then, using this method, and with a random coupling constant configuration, we obtain a lower bound for the ground state entropy density of the square, triangular, and hexagonal two-dimensional lattices with free

Thomas A. Ivey

The geodesics for a sub-Riemannian metric on a three-dimensional contact manifold $M$ form a 1-parameter family of curves along each contact direction. However, a collection of such contact curves on $M$, locally equivalent to the solutions of a fourth-order ODE, are the geodesics of a sub-Riemannian metric only if a sequence of invariants vanish. The first

A. Volberg, P. Yuditskii

Solving inverse scattering problem for a discrete Sturm-Liouville operator with the fast decreasing potential one gets reflection coefficients $s_\pm$ and invertible operators $I+H_{s_\pm}$, where $ H_{s_\pm}$ is the Hankel operator related to the symbol $s_\pm$. The Marchenko-Fadeev theorem (in the continuous case) and the Guseinov theorem (in the discrete

T. S. Evans

The vacuum energy density or free energy of a free charged Bose gas at non-zero densities is studied in the context of the debate about Multiplicative Anomalies. Some zeta-function regularised calculations of the free energy in the literature are reexamined, clarified and extended. A range of apparently distinct answers can obtained. Equivalent dimensional r

S. Baek, N. G. Deshpande, X. -G. He, P. Ko

In this paper we study $Z&#39;$ contribution to $g -2$ of the muon anomalous magnetic dipole moment in gauged $U(1)_{L_μ- L_τ}$ models. Here $L_i$ are the lepton numbers. We find that there are three classes of models which can produce a large value of $g-2$ to account for possible discrepancy between the experimental data and the Standard Model prediction.

Kiwoon Choi

We present a supersymmetric axion model in which the fermionic superpartner of axion, i.e. the axino, corresponds to a sterile neutrino which would accommodate the LSND data with atmospheric and solar neutrino oscillations.

Lee Samuel Finn

Technical discussions of the Laser Interferometer Gravitational Wave Observatory (LIGO) sensitivity often focus on its effective sensitivity to gravitational waves in a given band; nevertheless, the goal of the LIGO Project is to ``do science.&#39;&#39; Exploiting this new observational perspective to explore the Universe is a long-term goal, toward which LI

Lapo Casetti, E. G. D. Cohen, Marco Pettini

The phase transition in the mean-field XY model is shown analytically to be related to a topological change in its configuration space. Such a topology change is completely described by means of Morse theory allowing a computation of the Euler characteristic--of suitable submanifolds of configuration space--which shows a sharp discontinuity at the phase tran

S. Mossa, G. Monaco, G. Ruocco

We study the interaction of the relaxation processes with the density fluctuations by molecular dynamics simulation of a flexible molecule model for o-terphenyl (oTP) in the liquid and supercooled phases. We find evidence, besides the structural relaxation, of a secondary vibrational relaxation whose characteristic time, few ps, is slightly temperature depen

Charles W. Danforth, William P. Blair, John C. Raymond

The XA region of the Cygnus Loop is a complex zone of radiative and nonradiative shocks interacting with interstellar clouds. We combine five far ultraviolet spectral observations from the Hopkins Ultraviolet Telescope (HUT), a grid of 24 IUE spectra and a high-resolution longslit Halpha spectrum to study the spatial emission line variations across the regio

Gerard Gilmore, Rosemary F. G. Wyse

The star formation history of a galaxy, explicitely here our Milky Way Galaxy, where the most detailed information is attainable, is the convolution of two functions. One function describes the rate of formation of the stars which are today in the Galaxy. The second describes the assembly of those stars into the present Galactic potential well. There is dire

I. Ferreras, J. Silk

A simple chemical enrichment code is described where the two basic mechanisms driving the evolution of the ages and metallicities of the stellar populations are the star formation efficiency and the fraction of gas ejected from the galaxy. Using the observed Tully-Fisher relation in different passbands as a constraint, it is found that a steep correlation be

Scott A. Hughes

The inspiral of a ``small&#39;&#39; ($μ\sim 1-100 M_\odot$) compact body into a ``large&#39;&#39; ($M \sim 10^{5-7} M_\odot$) black hole is a key source of gravitational radiation for the space-based gravitational-wave observatory LISA. The waves from such inspirals will probe the extreme strong-field nature of the Kerr metric. In this paper, I investigate t

Gordon Baym

This talk traces the history of RHIC over the last two decades, reviewing the scientific motivations underlying its design, and the challenges and opportunities the machine presents.

G. Giedke, L. -M. Duan, J. I. Cirac, P. Zoller

We prove that all inseparable Gaussian states of two modes can be distilled into maximally entangled pure states by local operations. Using this result we show that a bipartite Gaussian state of arbitrarily many modes can be distilled if and only if its partial transpose is not positive.

I. Hinchliffe, N. Kersting

If the geometry of space-time is $\nc$, i.e. $[x_μ,x_ν]=i θ_{μν}$, then $\nc$ $\cpviolng$ effects may be manifest at low energies. For a $\nc$ scale $Λ\equiv θ^{-1/2} \leq 2 TeV$, $\cpviol$ from $\ncg$ is comparable to that from the Standard Model (SM) alone: the $\nc$ contributions to $ε$ and $ε&#39;/ε$ in the $K$-system, may actually dominate over the Stan

Matt Mackie, Jyrki Piilo, Kalle-Antti Suominen, Juha Javanainen

We theoretically examine photoassociation of a two-component Fermi degenerate gas, focusing on light-induced atom-atom interactions as a means to raise the critical temperature of the BCS transition to a superfluid state. As it stands, photoassociation-induced superfluidity is limited by spontaneous decay to experimentally inconvenient light intensities [Mac

P. Kaste, A. Kehagias, H. Partouche

We consider M-theory on compact spaces of G_2 holonomy constructed as orbifolds of the form (CY x S^1)/Z_2 with fixed point set Σon the CY. This describes N=1 SU(2) gauge theories with b_1(Σ) chiral multiplets in the adjoint. For b_1=0, it generalizes to compact manifolds the study of the phase transition from the non-Abelian to the confining phase through g

S. Karataglidis, M. B. Chadwick

Microscopic optical potentials for nucleon-nucleus (NA) scattering obtained from the full folding of the effective g matrices, solutions of the Bruckner-Bethe-Goldstone equation, with the densities of the target, are applied to the case of neutron-nucleus scattering. Given that the optical potentials are specified in all two-body angular momentum, spin and i

Jonathan D. Slavin, Priscilla C. Frisch

We present new calculations of the photoionization of interstellar matter within ~5 pc of the Sun (which we refer to as the Complex of Local Interstellar Clouds or CLIC) by directly observed radiation sources including nearby hot stars and the diffuse emission of the Soft X-ray Background (SXRB). In addition, we model the important, unobserved EUV emission b

Torsten A. Ensslin, Marcus Brueggen

(abridged) We present detailed 3-dimensional magneto-hydrodynamical simulations of the passage of a radio plasma cocoon filled with turbulent magnetic fields through a shock wave. Taking into account synchrotron, inverse Compton and adiabatic energy losses and gains we evolved the relativistic electron population to produce synthetic polarisation radio maps.

W. Kummer

The S-matrix is invariant with respect to the variation of any (global) parameter involved in the gauge fixing conditions, if that variation is accompanied by a certain redefinition of the basis of polarization vectors. Renormalizability of the underlying gauge theory is not required. The proof is nonperturbative and, using the `extended&#39; BRS transformat

V. B. Bezerra, L. P. Colatto, M. E. X. Guimaraes, e R. M. Teixeira Filho

We consider scalar and spinor particles in the spacetime of a domain wall in the context of low energy effective string theories, such as the generalized scalar-tensor gravity theories. This class of theories allows for an arbitrary coupling of the wall and the (gravitational) scalar field. First, we derive the metric of a wall in the weak-field approximatio

A. A. Raduta, O. Haug, F. Simkovic, Amand Faessler

A model many-body Hamiltonian describing an heterogenous system of paired protons and paired neutrons and interacting among themselves through monopole particle-hole and monopole particle-particle interactions is used to study the double beta decay of Fermi type. The states are described by time dependent approaches choosing as trial functions coherent state

K. Kakuyanagi, K. Kumagai, Yuji Matsuda

We report a site-selective ^{17}O spin-lattice relaxation rate T_1^{-1} in the vortex state of underdoped YBa_2Cu_4O_8. We found that T_1^{-1} at the planar sites exhibits an unusual nonmonotonic NMR frequency dependence. In the region well outside the vortex core, T_1^{-1} cannot be simply explained by the density of states of the Doppler-shifted quasiparti

V. N. Krivoruchko, E. A. Koshina

We study theoretically the dc Josephson tunnel current for a junction of two proximity S/F bilayers of a massive superconductor (S) / a thin ferromagnet (F) separated by an insulating (I) barrier. The dependence of the critical current on the relative orientation of the F layers magnetization is analyzed within the microscopic theory of the proximity effect

Alois Mair, Alipasha Vaziri, Gregor Weihs, Anton Zeilinger

So far experimental confirmation of entanglement has been restricted to qubits, i.e. two-state quantum systems including recent realization of three- and four-qubit entanglements. Yet, an ever increasing body of theoretical work calls for entanglement in quantum system of higher dimensions. Here we report the first realization of multi-dimensional entangleme

The DELPHI Collaboration, P. Abreu

A new precise measurement of |V_{cb}| and of the branching ratio BR(\bar{B^0} -> D^{*+} \ell^- \bar{ν_\ell}) has been performed using a sample of about 5000 semileptonic decays \bar{B^0} -> D^{*+} \ell^- \bar{ν_\ell}, selected by the DELPHI detector at LEP I by tagging the soft pion from D^{*+} -> D^0 π^+. The results are: V_{cb}=(39.0 +/- 1.5 (stat.) ^{+2.5

D. Dutta, S. V. S. Sastry, A. K. Mohanty, K. Kumar

The hard photon productions from bremsstrahlung and annihilation with scattering that arise at two loop level are estimated from a chemically non-equilibrated quark gluon plasma using the frame work of thermal field theory. Although, the rate of photon production is suppressed due to unsaturated phase space, the above suppression is relatively smaller than e

Z. W. Zhao, S. L. Li, Y. M. Ni, H. P. Yang

By doing magnetization measurements during magnetic field sweeps on thin films of the new superconductor $MgB_2$, it is found that in a low temperature and low field region small flux jumps are taking place. This effect strongly suppresses the central magnetization peak leading to reduced nominal superconducting critical current density at low temperatures.

Jun Yokogawa, Ken&#39;ichi Torii, Takayoshi Kohmura, Katsuji Koyama

This paper has been withdrawn because the class file must not be uploaded.

Xiaoguang Wang

We provide several schemes to construct the continuous-variable SWAP gate and present a Hermitian generalized many-body continuous controlled^n-NOT gate. We introduce and study the hybrid controlled-NOT gate and controlled-SWAP gate, and physical realizations of them are discussed in trapped-ion systems. These continuous-variable and hybrid quantum gates may

Yongseok Oh, Alexander I. Titov, T. -S. H. Lee

We study the role of the nucleon resonances ($N^*$) in $ω$ photoproduction by using the quark model resonance parameters predicted by Capstick and Roberts. The employed $γN \to N^*$ and $N^* \to ωN$ amplitudes include the configuration mixing effects due to the residual quark-quark interactions. The contributions from the nucleon resonances are found to be i

B. M. Gaensler, P. O. Slane, E. V. Gotthelf, G. Vasisht

Important constraints on the properties of the Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs) can be provided by their associations with supernova remnants (SNRs). We have made a radio search for SNRs towards the AXPs RX J170849-400910 and 4U 0142+61 - we find that the former lies near a possible new SNR with which it is unlikely to be ph

Yi-Xin Chen, Dong Yang

We consider one copy of a quantum system prepared with equal prior probability in one of two non-orthogonal entangled states of multipartite distributed among separated parties. We demonstrate that these two states can be optimally distinguished in the sense of conclusive discrimination by local operations and classical communications(LOCC) alone. And this p

Ali Mostafazadeh

We address the problem of identifying the (nonstationary) quantum systems that admit supersymmetric dynamical invariants. In particular, we give a general expression for the bosonic and fermionic partner Hamiltonians. Due to the supersymmetric nature of the dynamical invariant the solutions of the time-dependent Schrödinger equation for the partner Hamiltoni

Antony Valentini

It is argued that our universe happens to be in a state of statistical equilibrium at the hidden-variable level, such that nonlocality is masked by quantum noise. To account for this &#39;quantum equilibrium&#39;, we outline a subquantum statistical mechanics in configuration space, and an H-theorem analogous to the classical coarse-graining H-theorem. Found

Alan S. Fisher

The PEP-II B Factory at SLAC has been in operation with the BABAR detector since the summer of 1999. The peak currents and luminosity steadily increased through the end of the 2000 run on October 31. By that time, 0.75 A of electrons (the design current) routinely collided with 1.4 A of positrons in 657 bunches, to give a peak luminosity of 2.6E33 cm^{-2} s^

Claudio Conti, Stefano Trillo

In the theory of optical gap solitons, slowly-moving finite-amplitude Lorentzian solutions are found to mediate the transition from bright to coexistent dark-antidark solitary wave pairs when the laser frequency is detuned out of the proper edge of a dynamical photonic bandgap. Catastrophe theory is applied to give a geometrical description of this strongly

A. P. Zuker, J. Duflo, S. Lenzi, G. Martinez-Pinedo

A Fock space representation of the monopole part of the Coulomb potential is presented. Quantum effects show through a small orbital term in $l(l+1)$. Once it is averaged out, the classical electrostatic energy emerges as an essentially exact expression, which makes it possible to eliminate the Nolen-Schiffer anomaly, and to estimate neutron skins and the ev

Jacopo Bellazzini

We demonstrate how the Holder regularity of a given signal is a lower bound for the Grassberger-Procaccia correlation dimension of strange attractors.

Dan Abramovich, Tyler J. Jarvis

In this note we give a new, natural construction of a compactification of the stack of smooth r-spin curves, which we call the stack of stable twisted $r$-spin curves. This stack is identified with a special case of a stack of twisted stable maps of Abramovich and Vistoli. Realizations in terms of admissible G_m-spaces and Q-line bundles are given as well. T

N. F. Benschop

Decomposition of any Boolean Function BF_n of n binary inputs into an optimal inverter coupled network of Symmetric Boolean functions SF_k (k \leq n) is described. Each SF component is implemented by Threshold Logic Cells, forming a complete and compact T-Cell Library. Optimal phase assignment of input polarities maximizes local symmetries. The &#34;rank spe

Sergey Fomin, Andrei Zelevinsky

In an attempt to create an algebraic framework for dual canonical bases and total positivity in semisimple groups, we initiate the study of a new class of commutative algebras.

Yi-Zhi Huang

We introduce and study completely-extendable conformal intertwining algebras. Based on results obtained in other papers, various examples are given. Duals of these algebras are constructed and nondegenerate such algebras are defined. We prove that the double dual of such a nondegenrate algebra is equal to itself. We explain using a table that these nondegene

Amnon Besser, Pieter Moree

Let A be an m-dimensional vector with positive real entries. Let A_{i,j} be the vector obtained from A on deleting the entries A_i and A_j. We investigate some invariant and near invariants related to the solutions E (m-2 dimensional vectors with entries either +1 or -1) of the linear inequality |A_i-A_j| < <E,A_{i,J}> < A_i+A_j, where <,> denotes the usual

Nobuhiro Asai, Izumi Kubo, Hui-Hsiung Kuo

A class of growth functions $u$ is introduced to construct Hida distributions and test functions. The Legendre transform $\ell_{u}$ of $u$ is used to define a sequence $\a(n)=(\ell_{u}(n) n!)^{-1}, n\geq 0$, of positive numbers. From this sequence we get a CKS-space. Under various conditions on $u$ we show that the associated sequence $\{\a(n)\}$ satisfies t

Keiji Oguiso

A few facts concerning the phrase &#34;the automorphism groups become larger at special points of the moduli of K3 surfaces&#34; are presented. It is also shown that the automorphism groups are of infinite order over a dense subset in any one-dimensional non-trivial family of projective K3 surfaces.

Mukund Rangamani

We argue that the holographic dual to little string theories at finite temperature suffers from a Gregory-Laflamme like instability, providing an alternative explanation to the results of hep-th/0012258.

Norikazu Yamada, Shoji Hashimoto

We report on lattice calculations of the $B$ meson decay constant and the B-parameters using the NRQCD action for heavy quark. We performed a set of calculations at three lattice spacings in the quenched approximation in order to investigate the systematic uncertainty associated with the lattice discretization. Our results indicate that the systematic error

J. Kontros, K. Kontros, A. Lengyel

Several Regge-phenomenological models of forward scattering at high energies are considered. It was found that one of them corresponds to the form of finite series in log s with additional terms that represent the exchanges of non-degenerate Regge-trajectories. These trajectories are unique for both the scattering and resonance regions and satisfy the most r

Johann Rafelski, Giorgio Torrieri, Jean Letessier

We compare chemical and thermal analysis of the SPS Pb--Pb results at $158A$ GeV, and present a first chemical analysis of RHIC results. We show how a combined analysis of several strange hadron resonances can be used in a study of freeze-out dynamics.

John B. Kogut, Dominique Toublan, D. K. Sinclair

SU(2) lattice gauge theory with four flavors of quarks is studied at nonzero chemical potential $μ$ and temperature $T$ by computer simulation and Effective Lagrangian techniques. Simulations are done on $8^4$, $8^3 \times 4$ and $12^3 \times 6$ lattices and the diquark condensate, chiral order parameter, Wilson line, fermion energy and number densities are