June 2002 arXiv papers — page 9

Helga Baum, Ines Kath

(This is a revised version of the paper) - In the present paper we study the geometry of doubly extended Lie groups with their natural biinvariant metric. We describe the curvature, the holonomy and the space of parallel spinors. This is completely done for all simply connected groups with biinvariantmetric of Lorentzian signature $(1,n-1)$, of signature $(2

Ludwik Dabrowski, Giovanni Landi

We study some generalized instanton algebras which are required to describe `instantonic complex rank 2 bundles'. The spaces on which the bundles are defined are not prescribed from the beginning but rather are obtained from some natural requirements on the instantons. They turn out to be quantum 4-spheres $S^4_q$, with $q\in\IC$, and the instantons are

M. Bordag, A. Yurov

We consider the question which potentials in the action of a (1+1) dimensional scalar field theory allowing for spontaneous symmetry breaking have quantum fluctuations corresponding to reflectionless scattering data. The general problem of restoration from known scattering data is formulated and a number of explicit examples is given. Only certain sets of re

M. A. Betemps, M. B. Gay Ducati, M. V. T. Machado

We report on the results obtained in the study of the parton saturation effects, taken into account through the multiscattering Glauber-Mueller approach, applied to the Drell-Yan (DY) process described in the color dipole picture. As a main result, one shows that those effects play an important role in the estimates of the DY differential cross section atRHI

Alfred Mueller

We describe the light-cone wavefunction in the saturation regime in terms of the density of gluons per unit of transverse phase space, the occupation number, and in terms of the color charge correlator. The simple McLerran- Venugopalan model gives what are claimed to be general results for the phase space gluon density, but it does not well describe the gene

F. Cano, B. Pire

We study deeply virtual Compton scattering (DVCS) on a deuteron target. We model the Generalized Quark Distributions in the deuteron by using the impulse approximation for the lowest Fock-space state. Numerical predictions are given for the unpolarized cross sections for the kinematical regimes relevant for JLab and HERMES at HERA. Differential cross section

Marco Mirazita

The high energy two-body photodisintegration of the deuteron is an ideal reaction for the identification of quark effects in the nuclei. In particular, the study of this reaction in the few GeV region can clarify the transition from the nucleonic degrees of freedom to the QCD picture of hadrons. The CLAS large angle spectrometer of Hall B at TJNAF allowed fo

A. Bottino, G. Fiorentini, N. Fornengo, B. Ricci

We investigate whether present data on helioseismology and solar neutrino fluxes may constrain WIMP--matter interactions in the range of WIMP parameters under current exploration in WIMP searches. We find that, for a WIMP mass of 30 GeV, once the effect of the presence of WIMPs in the Sun's interior is maximized, the squared isothermal sound speed is mod

Kerstin E. Kunze, Mairi Sakellariadou

Graviton production due to collapsing extra dimensions is studied. The momenta lying in the extra dimensions are taken into account. A $D$-dimensional background is matched to an effectively four-dimensional standard radiation dominated universe. Using observational constraints on the present gravitational wave spectrum, a bound on the maximal temperature at

F. Becattini

The analyses of hadron production in the framework of the statistical hadronisation model are reviewed. The analysis of average multiplicities in collisions at relatively low centre-of-mass energy confirms previous findings, namely the universality of hadronisation temperature and of strange to non-strange quark production rate. The study of transverse momen

M. Fontannaz, J. Ph. Guillet, G. Heinrich

We study the photoproduction of large-p_T charged hadrons in e p collisions, both for the inclusive case and for the case where a jet in the final state is also measured. Our results are obtained by a NLO generator of partonic events. We discuss the sensitivity of the cross section to the renormalisation and factorisation scales, and to various fragmentation

C. R. Allton, S. Ejiri, S. J. Hands, O. Kaczmarek

A study of QCD at non-zero chemical potential, mu, and temperature, T, is performed using the lattice technique. The transition temperature (between the confined and deconfined phases) is determined as a function of mu and is found to be in agreement with other work. In addition the variation of the pressure and energy density with mu is obtained for small p

Han-Kuei Fu, Xiao-Gang He, Yu-Kuo Hsiao, Jian-Qing Shi

In this paper we study CP violation in $B\to PP$ decays in the Standard Model using SU(3) flavor symmetry. With SU(3) symmetry only seven hadronic parameters are needed to describe $B\to PP$ decays in the SM when annihilation contributions are neglected. The relevant hadronic parameters can be determined using known experimental data from $B\to ππ$ and $B\to

T. Kiyan, T. Maekawa, M. Masuda, H. Taira

The gauge invariant and anomaly-free 331 model is studied with $R_ξ$ gauges in order to see which of the right-handed singlet between the case (i), assigning the bosonic singlet to the counterpart of 3 and $\bar 3$ representations, and the case (ii), assigning fermionic siglet to the counterpart of the left-handed 3 representation and assigning the antifermi

Thomas Jorg

We construct a parametrization of a Fixed Point (FP) Dirac operator and apply it in quenched lattice QCD. The symmetry requirements for a general lattice Dirac operator are discussed and an efficient way to make a practical construction of general lattice Dirac operators is provided. We use such a lattice Dirac operator to approximately solve the Renormaliza

V. K. Mitrjushkin

The functional integral representation for fermionic observables on the lattice is studied. In particular, Grassmannian representations of the scalar $\hatJ^{(S)}$ and pseudoscalar $\hatJ^{(P)}$ currents and pseudoscalar correlator are derived. It is also discussed the connection between the fermionic Fock space and boundary conditions along the time directi

Simon Hauswirth

The classically perfect Fixed-Point fermion action for lattice QCD, a highly improved discretization of the continuum theory that preserves chiral symmetry, is constructed in this thesis and a parallel work by T. Jorg. In the framework of the BGR collaboration, we perform studies in quenched light hadron spectroscopy with this new action in order to examine

The Focus Collaboration

Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic branching ratios. We obtain values of D+ to K*munu/k2pi = 0.602 +/- 0.010 +/- 0.021 and Ds to phimunu/phipi = 0.54 +/- 0.033 +/- 0.048. Our result D+ result includes the effects of s-wave interferenc

K. Kasahara, E. Mochizuki, S. Torii, T. Tamura

We observed atmospheric gamma-rays around 10 GeV at balloon altitudes (15~25 km) and at a mountain (2770 m a.s.l). The observed results were compared with Monte Carlo calculations to find that an interaction model (Lund Fritiof1.6) used in an old neutrino flux calculation was not good enough for describing the observed values. In stead, we found that two oth

A. Badertscher, P. Crivelli, M. Felcini, S. N. Gninenko

We report on a direct search for a three-body decay of the orthopositronium into a photon and two penetrating particles, o-Ps -> gamma + X1 + X2. The existence of this decay could explain the discrepancy between the measured and the predicted values of the orthopositronium decay rate. From the analysis of the collected data a single candidate event is found,

B. Aubert, BABAR Coll

We present preliminary results of the analyses of B into h pi0 and B into hK0 decays (with h = pi+/-, K+/-) from a sample of approximately 60 million BB pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find evidence for a signal in B+ into pi+ pi0, and we measure the branching fraction BR (B+ into pi+ pi0) = (4.1_{-

V. M. Khatsymovsky

Encountered in the literature generalisations of general relativity to independent area variables are considered, the discrete (generalised Regge calculus) and continuum ones. The generalised Regge calculus can be either with purely area variables or, as we suggest, with area tensor-connection variables. Just for the latter, in particular, we prove that in a

Bernard Parisse

In this note, we fill a gap in the proof of the heuristic GCD in the multivariate case made by Char, Geddes and Gonnet (JSC 1989) and give some additionnal information on this method.

R. G. Hennig, P. A. Fedders, A. E. Carlsson

A structural model of hydrogenated amorphous silicon containing an isolated dangling bond is used to investigate the effects of electron interactions on the electronic level splittings, localization of charge and spin, and fluctuations in charge and spin. These properties are calculated with a recently developed density-matrix correlation-energy functional a

Amit Ghosal, Catherine Kallin, A. John Berlinsky

The d-wave vortex lattice state is studied within the framework of Bogoliubov-de Gennes (BdG) mean field theory. We allow antiferromagnetic (AFM) order to develop self-consistently along with d-wave singlet superconducting (dSC) order in response to an external magnetic field that generates vortices. The resulting AFM order has strong peaks at the vortex cen

John J. Quinn, Arkadiusz Wojs

If the Zeeman energy is small, the lowest energy excitations of a two dimensional electron gas at filling factor nu=1 are spin waves (spin flip excitations). At nu slightly larger (smaller) than unity, reversed spin electrons (spin holes) can form bound states with K spin waves that are known as skyrmions, S_K^- (antiskyrmions, S_K^+). It is suggested in thi

L. G. C. Rego, A. R. Rocha, V. Rodrigues, D. Ugarte

Gold nanowires generated by mechanical stretching have been shown to adopt only three kinds of configurations where their atomic arrangements adjust such that either the [100], [111] or [110] zone axes lie parallel to the elongation direction. We have analyzed the relationship between structural rearrangements and electronic transport behavior during the elo

M. A. Avila, S. L. Bud'ko, P. C. Canfield

We report temperature dependent resistivity, specific heat, magnetic susceptibility and thermoelectric power measurements made on the heavy fermion system YbNi2B2C, for both as grown and annealed single crystals. Our results demonstrate a significant variation in the temperature dependent electrical resistivity and thermoelectric power between as grown cryst

P. Toulemonde, N. Musolino, H. L. Suo, R. Flukiger

Dense pure and doped (Mg1-xAx)B2 samples with A = Na, Ca, Cu, Ag, Zn and Al were synthesized at high pressure - high temperature in a multi anvils press (3.5-6 GPa, 900-1000C) for x up to 0.20. They were studied by x-ray diffraction, scanning electron microscopy and their superconducting properties were investigated by a.c. susceptibility, magnetization and

E. Zaccarelli, G. Foffi, K. A. Dawson, S. V. Buldyrev

Previous theoretical, along with early simulation and experimental, studies have indicated that particles with a short-ranged attraction exhibit a range of new dynamical arrest phenomena. These include very pronounced reentrance in the dynamical arrest curve, a logarithmic singularity in the density correlation functions, and the existence of `attractive&#39

M. Angst, R. Puzniak, A. Wisniewski, J. Roos

In a recent paper [Phys. Rev. B 66, 012501 (2002)], torque data measured on a MgB2 single crystal in fields from 10 to 60 kOe at 10 K were presented. The authors obtained the anisotropy gamma by fitting a theoretical expression to the data and concluded that the anisotropy is field independent gamma \approx 4.3. They also reported the observation of "int

S. Leitenmeier, H. Bielefeldt, G. Hammerl, A. Schmehl

It is shown that the critical currents of high-Tc superconducting tapes fabricated by the coated conductor technologies are enhanced considerably if grain arrangements with large effective grain boundary areas are used. Increasing the aspect ratios of the grains reduces the deleterious effects of the grain boundaries. A practical road to competitive high-Tc

M. Kindermann, C. W. J. Beenakker

A quantum mechanical theory is developed for the statistics of momentum transferred to the lattice by conduction electrons. Results for the electromechanical noise power in the semiclassical diffusive transport regime agree with a recent theory based on the Boltzmann-Langevin equation. All moments of the transferred momentum are calculated for a single-chann

J. Reinisch, A. Heuer

The role of Coulomb interaction between the mobile particles in ionic conductors is still under debate. To clarify this aspect we perform Monte Carlo simulations on two simple lattice models (Counter Ion Model and Random Energy Model) which contain Coulomb interaction between the positively charged mobile particles, moving on a static disordered energy lands

Joachim Krug

Several aspects of the theory of epitaxial crystal growth from atomic or molecular beams are developed from the perspective of statistical physics. Lectures are devoted to the rate equation theory of two-dimensional nucleation and its limitations; the growth of multilayer wedding cakes in the presence of strong step edge barriers; the continuum theory of mou

Meik Hellmund, Wolfhard Janke

We derive high-temperature series expansions for the free energy and the susceptibility of random-bond $q$-state Potts models on hypercubic lattices using a star-graph expansion technique. This method enables the exact calculation of quenched disorder averages for arbitrary uncorrelated coupling distributions. Moreover, we can keep the disorder strength $p$

Yu Zhu, Tsung-han Lin, Qing-feng Sun

We develop a theory for the nonequilibrium coherent transport through a mesoscopic region, based on the nonequilibrium Green function technique. The theory requires the weak coupling between the central mesoscopic region and the multiple electrodes connected to it, but allows arbitrary hopping and interaction in the central region. An equation determining th

A. Podesta', G. Fantoni, P. Milani, C. Guida

We present the result of a systematic study of the tribological properties of industrial Polytetrafluorethylene (PTFE)-based coatings carried out with an atomic force microscope. A new characterization protocol allowed the reliable and quantitative assessment of the friction coefficient and adhesion forces at the sub-micrometer scale even for highly corrugat

Rusko Ruskov, Alexander N. Korotkov

We show that two identical solid-state qubits can be made fully entangled (starting from completely mixed state) with probability 1/4 just measuring them by a detector, equally coupled to the qubits. This happens in the case of repeated strong (projective) measurements as well as in a more realistic case of weak continuous measurement. In the latter case the

S. Paulin-Henriksson, P. Baillon, A. Bouquet, B. J. Carr

We report the discovery of a microlensing candidate projected 2'54" from the center of M32, on the side closest to M31. The blue color (R-I= 0.00 +/- 0.14) of the source argues strongly that it lies in the disk of M31, while the proximity of the line of sight to M32 implies that this galaxy is the most likely host of the lens. If this interpretation

Lifan Wang, Dietrich Baade, Peter Hoeflich, J. Craig Wheeler

High-quality spectropolarimetric data of SN 2002ap were obtained with the ESO Very Large Telescope Melipal (+ FORS1) at 3 epochs that correspond to -6, -2, and +1 days for a V maximum of 9 Feb 2002. The polarization spectra show three distinct broad features at 400, 550, and 750 nm that evolve in shape, amplitude and orientation in the Q-U plane. The continu

Kevin M. McLin, John T. Stocke, R. J. Weymann, Steven V. Penton

We have conducted pointed redshift surveys for galaxies in the direction of bright AGN whose HST far-UV spectra contain nearby (cz <~ 30,000 kms), low column density (12.5 <= log N_{HI} (cm s^{-2}) <= 14.5) Ly-alpha forest absorption systems. Here we present results for four lines-of-sight which contain nearby (cz <~ 3000 kms) Ly-alpha absorbers in galaxy vo

R. J. Wilman, A. C. Edge, R. M. Johnstone, A. C. Fabian

The origin of rovibrational H_2 emission in the central galaxies of cooling flow clusters is poorly understood. Here we address this issue using data from our near-infrared spectroscopic survey of 32 of the most line luminous such systems, presented in the companion paper by Edge et al. (2002). We consider excitation by X-rays from the surrounding intraclust

Rien van de Weygaert

The presentations in the 2nd Hellenic Cosmology Workshop covered a broad range of cosmological subjects. Following the analogy with the architectural masters of Ancient Greece, the contributions are presented in ``architectural&#39;&#39; sessions. The session on the ``Architects&#39;&#39; involves ``fundamental cosmology&#39;&#39;, focussing on the topology

A. C. Edge, R. J. Wilman, R. M. Johnstone, C. S. Crawford

We present a large sample of H- and K-band spectra of 32 optically line luminous central cluster galaxies. We find significant rovibrational H_2 emission in 23 of these galaxies as well as H recombination and/or [FeII] emission in another 5. This represents a fourfold increase in the number of molecular line detections known. A number of the detections are o

Mark J. McCaughrean, Ralf-Dieter Scholz, Nicolas Lodieu

We have identified two late M dwarfs within 10 parsecs of the Sun, by cross-correlating the Luyten NLTT catalogue of stars with proper motions larger than 0.18 arcsec/yr, with objects lacking optical identification in the 2MASS data base. The 2MASS photometry was then combined with improved optical photometry obtained from the SuperCOSMOS Sky Surveys. The tw

G. Ghirlanda, A. Celotti, G. Ghisellini

We present the time integrated and time resolved spectral analysis of a sample of bright bursts selected with F_{peak}>20 phot cm^{-2} sec^{-1} from the BATSE archive. We fitted four different spectral models to the pulse time integrated and time resolved spectra. We compare the low energy slope of the fitted spectra with the prediction of the synchrotron th

S. Campana, L. Stella, F. Gastaldello, S. Mereghetti

SAX J1808.4-3658 is a unique source being the first Low Mass X-ray Binary showing coherent pulsations at a spin period comparable to that of millisecond radio pulsars. Here we present an XMM-Newton observation of SAX J1808.4-3658 in quiescence, the first which assessed its quiescent luminosity and spectrum with good signal to noise. XMM-Newton did not reveal

M. Vivekanand

Pravdo et al (1997) claimed that the phase resolved x-ray spectrum in Crab pulsar (PSR B0531+21) shows a spectral hardening at the leading edge of the first peak of its integrated profile; this was a new and unexpected result. This article reanalyzes their data, as well as some other related data, and argues that the spectrum is as likely to be unvarying (i.

Philip Kaaret

We present results from a 47 ks observation of the Andromeda galaxy, M31, using the High-Resolution Camera of the Chandra X-Ray Observatory. We detect 142 point sources spanning three orders of magnitude in luminosity, from $L_X = 2\times 10^{35} \rm erg s^{-1}$ to $L_X = 2\times 10^{38} \rm erg s^{-1}$ in the 0.1-10 keV band. The X-ray source location accur

J. V. Smoker, L. M. Haffner, F. P. Keenan, R. D. Davies

We present Westerbork Synthesis Radio Telescope HI images, Lovell Telescope multibeam HI wide-field mapping, Wisconsin H-alpha Mapper facility images, William Herschel Telescope longslit echelle CaII observations, and IRAS ISSA 60 and 100 micron coadded images towards the intermediate velocity cloud located in the general direction of the M15 globular cluste

Rahul Dave, R. R. Caldwell, Paul J. Steinhardt

We analyze the evolution of energy density fluctuations in cosmological scenarios with a mixture of cold dark matter and quintessence, in which the quintessence field is modeled by a constant equation of state. We obtain analytic expressions for the time evolution of the quintessence perturbations in models with light fields. The fluctuations behave analogou

I. Kravchenko

Upper limits are presented on the diffuse flux of ultra-high energy $ν_e$, based on analysis of data taken by the RICE experiment during August, 2000. The RICE receiver array at South Pole monitors cold ice for radio-wavelength Cherenkov radiation resulting from neutrino-induced in-ice showers. For energies above 1 EeV, RICE is an effective detector of over

Dong-Woo Kim, Giuseppina Fabbiano

We report the results of the Chandra ACIS sub-arcsecond resolution X-ray observation of the archetypal merger radio galaxy NGC 1316 (Fornax A). We confirm the presence of fine sub-structures in the hot Interstellar Medium (ISM). Some of these are likely to result from interaction with the radio jets, while others may be related to a complex intermingling of

Michal Fabinger, John McGreevy

We study string theory on a non-singular time-dependent orbifold of flat space, known as the `null-brane&#39;. The orbifold group, which involves only space-like identifications, is obtained by a combined action of a null Lorentz transformation and a constant shift in an extra direction. In the limit where the shift goes to zero, the geometry of this orbifol

Douglas C. Leonard, Alexei V. Filippenko, Ryan Chornock, Ryan J. Foley

The early-time optical spectrum of the Type Ic supernova (SN) 2002ap was characterized by unusually broad features, leading some authors to designate it a &#34;hypernova.&#34; We present optical spectropolarimetry of this object 16 and 37 days after the estimated date of explosion. After correcting for interstellar polarization, we find evidence for a high l

Chris Waltham

Since 1945 Canada has had a nuclear power industry based on reactor design which uses natural uranium and heavy water. The tortuous and improbable sequence of events which led to this situation is examined.

D. N. Wren, D. L. Bertsch, S. Ritz

It is well known that high-energy emission (MeV-GeV) has been observed in a number of gamma-ray bursts, and temporally-extended emission from lower energy gamma rays through radio wavelengths is well established. An important observed characteristic of some bursts at low energy is quiescence: an initial emission followed by a quiet period before a second (po

Zvi Bern, Lance Dixon, Carl Schmidt

We compute the QCD corrections to the gluon fusion subprocess gg to gamma gamma, which forms an important component of the background to the search for a light Higgs boson at the LHC. We study the dependence of the improved pp to gamma gamma X background calculation on the factorization and renormalization scales, on various choices for photon isolation cuts

Keiji Matsumoto, Toshiyuki Shimono, Andreas Winter

The purpose of these notes is to discuss the relation between the additivity questions regarding the quantities (Holevo) capacity of a quantum channel T and entanglement of formation of a given bipartite state. In particular, using the Stinespring dilation theorem, we give a formula for the channel capacity involving entanglement of formation. This can be us

M. Guagnelli, F. Palombi, R. Petronzio, N. Tantalo

A novel method to calculate f_B on the lattice is introduced, based on the study of the dependence of finite size effects upon the heavy quark mass of flavoured mesons and on a non-perturbative recursive finite size technique. We avoid the systematic errors related to extrapolations from the static limit or to the tuning of the coefficients of effective Lagr

Stephan Dürr, Philippe de Forcrand

Compact U(1) theory in 4 dimensions is used to compare the modified iterative and the Laplacian fixing to lattice Landau gauge in a controlled setting, since in the Coulomb phase the lattice theory must reproduce the perturbative prediction. It turns out that on either side of the phase transition clear differences show up and in the Coulomb phase the abilit

Andrea Dieball, Hardo Mueller, Eva K. Grebel

Based on the Bica et al. (1999) catalogue we studied the star cluster system of the LMC and provide a new catalogue of all binary and multiple cluster candidates found. We performed Monte Carlo simulations and produced artificial cluster distributions that we compared with the real one in order to check how many of the found cluster pairs and groups can be e

A. Finoguenov, C. Jones, H. Boehringer, T. J. Ponman

Through a 3d-modeling of ASCA observations, we performed a spatially resolved X-ray spectroscopic study, extending to radii exceeding 150 kpc, for a sample of 9 groups of galaxies. Combined with published ROSAT results, we conclude that these systems generally exhibit a strong temperature decline at outer radii. In our best case, NGC3268, this corresponds to

Anders S. Sorensen, Klaus Molmer

We propose to produce entanglement by measuring the transmission of an optical cavity. Conditioned on the detection of a reflected photon, pairs of atoms in the cavity are prepared in maximally entangled states. The success probability depends on the cavity parameters, but high quality entangled states may be produced with a high probability even for cavitie

D. Bruno, P. Facchi, S. Longo, P. Minelli

We study the dynamics of the populations of a model molecule endowed with two sets of rotational levels of different parity, whose ground levels are energy degenerate and coupled by a constant interaction. The relaxation rate from one set of levels to the other one has an interesting dependence on the average collision frequency of the molecules in the gas.

S. J. Martin, A. Kambili, A. B. Walker

The transport properties of organic light-emitting diodes in which the emissive layer is composed of conjugated polymers in the liquid-crystalline phase have been investigated. We have performed simulations of the current transient response to an illumination pulse via the Monte Carlo approach, and from the transit times we have extracted the mobility of the

Daniel E. Browne, Martin B. Plenio

Two-mode cavities can be prepared in quantum states which represent symmetric multi-qubit states. However, the qubits are impossible to address individually and as such cannot be independently measured or otherwise manipulated. We propose two related schemes to coherently transfer the qubits which the cavity state represents onto individual atoms, so that th

John D. Barrow, Sigbjorn Hervik

We study the evolution of the Weyl curvature invariant in all spatially homogeneous universe models containing a non-tilted gamma-law perfect fluid. We investigate all the Bianchi and Thurston type universe models and calculate the asymptotic evolution of Weyl curvature invariant for generic solutions to the Einstein field equations. The influence of compact

Daniele Tommasini

Einstein, Podolsky and Rosen (EPR) pointed out that the quantum-mechanical description of &#34;physical reality&#34; implied an unphysical, instantaneous action between distant measurements. To avoid such an action at a distance, EPR concluded that Quantum Mechanics had to be incomplete. However, its extensions involving additional &#34;hidden variables&#34;

Dongsu Bak, Kimyeong Lee

We find and explore a class of dyonic instanton solutions which can be identified as the supertubes connecting two D4 branes. They correspond to a single monopole string and a pair of monopole antimonopole strings from the worldvolume view point of D4 branes.

M. Rieutord, B. Dintrans

Two approximations, namely the subseismic approximation and the anelastic approximation, are presently used to filter out the acoustic modes when computing low frequency modes of a star (gravity modes or inertial modes). In a precedent paper (Dintrans & Rieutord 2001), we observed that the anelastic approximation gave eigenfrequencies much closer to the exac

Manuel Valin-Rodriguez, Antonio Puente, Llorens Serra, Enrico Lipparini

The spin-orbit coupling influences the total spin of semiconductor quantum dots. We analyze the theoretical prediction for the combined effects of spin-orbit coupling, weak vertical magnetic fields and deformation of the dot. Our results allow the characterization of the quantum dots as spin switches, controllable with electric gates.

Bei Zeng, Hui Zhai, Zhan Xu

We study the entanglement properties of some fractional quantum Hall liquids. We calculate the entanglement of the Laughlin wave function and the wave functions that are generated by the K-matrix using the modified entanglement measure of indistinguishable fermions that is first proposed by Paškauskas and You[1].

A. Echeverría-Enríquez, J. Marín-Solano, M. C. Muñoz-Lecanda, N. Román-Roy

A general study of symmetries in optimal control theory is given, starting from the presymplectic description of this kind of system. Then, Noether&#39;s theorem, as well as the corresponding reduction procedure (based on the application of the Marsden-Weinstein theorem adapted to the presymplectic case) are stated both in the regular and singular cases, whi

Munehisa Matsumoto, Synge Todo, Masaaki Nakamura, Chitoshi Yasuda

We have proposed the plaquette-singlet solid (PSS) ground state for the spin-1 antiferromagnetic Heisenberg two-leg ladder. Based on the PSS picture, we discuss the correspondence of the PSS state to the valence-bond solid (VBS) state of the ground state of spin-2 chain by introducing an appropriate composite spin picture. When the bond alternation is introd

Erez Berg, Ehud Altman, Assa Auerbach

The highly frustrated Heisenberg antiferromagnet on Checkerboard and Pyrochlore lattices is subject to strong quantum fluctuations. This problem is amenable to the Contractor Renormalization (CORE) algorithm, which systematically computes the effective interactions in a basis of local cluster eigenstates. CORE was recently used to derive the Plaquette Boson-

Kurt Johansson

We consider a discrete polynuclear growth (PNG) process and prove a functioal limit theorem for its convergrence to the Airy process. This generalizes previous results by Pr&#34;ahofer and Spohn. The result enables us to express the GOE largest eigenvalue (Tracy-Widom) distribution in terms of the Airy process. We also show some results and give a conjecture

P. Bieliavsky, M. Rooman, Ph. Spindel

We revisit the non-rotating massive BTZ black hole within a pseudo-Riemannian symmetric space context. Using classical symmetric space techniques we find that every such space intrinsically carries a regular Poisson structure whose symplectic leaves are para-hermitian symmetric surfaces. We also obtain a global expression of the metric yielding a dynamical d

Andrei Barvinsky, Alexander Kamenshchik, Andreas Rathke, Claus Kiefer

We construct the nonlocal braneworld action in the two-brane Randall-Sundrum model in a holographic setup alternative to Kaluza-Klein description: the action is written as a functional of the two metric and radion fields on the branes. This action effectively describes the dynamics of the gravitational field both on the branes and in the bulk in terms of the

Barbara Badełek, Jan Kwieciński, Beata Ziaja

Theoretical predictions for polarized nucleon structure function $g_1(x,Q^2)$ at low $Q^2$ are obtained in the framework of the Generalized Vector Meson Dominance model. Contributions from both light and heavy vector mesons are evaluated. In the photoproduction limit the first moment of $g_1$ is related to the static properties of nucleon via the Drell-Hearn

Shoichi Ichinose

The Kaluza-Klein theory and Randall-Sundrum theory are examined comparatively, with focus on the behavior of the five dimensional (Dirac) fermion in the dimensional reduction to four dimensions. They are properly treated using the Cartan formalism. In the KK case, the dual property between the electric and magnetic dipole moments is revealed in relation to t

Alain Connes, Michel Dubois-Violette

Some unexpected properties of the cubic algebra generated by the covariant derivatives of a generic Yang-Mills connection over the (s+1)-dimensional pseudo Euclidean space are pointed out. This algebra is Gorenstein and Koszul of global dimension 3 but except for s=1 (i.e. in the 2-dimensional case) where it is the universal enveloping algebra of the Heisenb

Zachary E. Wardell

In a previous investigation, a model of three-body motion was developed which included the effects of gravitational radiation reaction. The aim was to describe the motion of a relativistic binary pulsar that is perturbed by a third mass and look for resonances between the binary and third mass orbits. Numerical integration of an equation of relative motion t

PHOBOS Collaboration, B. B. Back

The ratios of charged antiparticles to particles have been obtained for pions, kaons and protons near midrapidity in central Au+Au collisions at sqrt(s_NN) = 200 GeV. Ratios of <pi->/<pi+> = 1.025 +/- 0.006 (stat.) +/- 0.018 (syst.), <K->/<K+> = 0.95 +/- 0.03 (stat.) +/- 0.03 (syst.) and <pbar>/<p> = 0.73 +/- 0.02 (stat.) +/- 0.03 (syst.) have been observed.

Zachary E. Wardell

A model of three-body motion is developed which includes the effects of gravitational radiation reaction. The radiation reaction due to the emission of gravitational waves is the only post-Newtonian effect that is included here. For simplicity, all of the motion is taken to be planar. Two of the masses are viewed as a binary system and the third mass, whose

Hiroaki Terao

In [5] (=Terao, H.: Multiderivations of Coxeter arrangements. Inventiones math., 148 (2002) 659--674), we constructed a basis for the contact-order filtration of the module of derivations on the orbit space of a finite real reflection group acting on an $\ell$-dimensional Euclidean space. Recently M. Yoshinaga constructed another basis for the contact-order

Yoshiharu Kawamura

We study the structure of cubic matrix mechanics based on three-index objects. It is shown that there exists a counterpart of canonical structure in classical mechanics.

Sungyun Kim, Gonzalo Ordonez

We consider a simple model of a classical harmonic oscillator coupled to a field. In standard approaches Langevin-type equations for {\it bare} particles are derived from Hamiltonian dynamics. These equations contain memory terms and are time-reversal invariant. In contrast the phenomenological Langevin equations have no memory terms (they are Markovian equa

A. Bouda, T. Djama

In this reply, we hope to bring clarifications about the reservations expressed by Floyd in his comments, give further explanations about the choice of the approach and show that our fundamental result can be reproduced by other ways. We also establish that Floyd&#39;s trajectories manifest some ambiguities related to the mathematical choice of the couple of

Italo Vecchi

A conjecture about the quantum nature of classical probabilites is set forth and discussed.

Y. S. Kim, Marilyn E. Noz

Gell-Mann&#39;s quarks are coherent particles confined within a hadron at rest, but Feynman&#39;s partons are incoherent particles which constitute a hadron moving with a velocity close to that of light. It is widely believed that the quark model and the parton model are two different manifestations of the same covariant entity. If this is the case, the ques

A. Bohm, N. L. Harshman, H. Walther

The Fourier transform is often used to connect the Lorentzian energy distribution for resonance scattering to the exponential time dependence for decaying states. However, to apply the Fourier transform, one has to bend the rules of standard quantum mechanics; the Lorentzian energy distribution must be extended to the full real axis $-\infty<E<\infty$ instea

B. Deb, G. S. Agarwal

We propose an experiment for entangling two spatially separated Bose-Einstein condensates by Bragg scattering of light. When Bragg scattering in two condensates is stimulated by a common probe, the resulting quasiparticles in the two condensates get entangled due to quantum communication between the condensates via probe beam. The entanglement is shown to be

Claude Crepeau, Daniel Gottesman, Adam Smith

Secure multi-party computing, also called &#34;secure function evaluation&#34;, has been extensively studied in classical cryptography. We consider the extension of this task to computation with quantum inputs and circuits. Our protocols are information-theoretically secure, i.e. no assumptions are made on the computational power of the adversary. For the we

Wang Xiang-bin

We show that the existing argument on the non-classicality of the continuous variable quantum teleportation (CVQT) experiment by the average fidelity criterion is incomplete therefore so far it is still unclear whether the CVQT experiment(Furusawa et al, Science,282, 706(1998)) is really non-classical.

L. Accardi, A. N. Pechen, I. V. Volovich

A new derivation of quantum stochastic differential equation for the evolution operator in the low density limit is presented. We use the distribution approach and derive a new algebra for quadratic master fields in the low density limit by using the energy representation. We formulate the stochastic golden rule in the low density limit case for a system cou

Brian P. Ingalls, Herbert M. Sauro

A sensitivity analysis of general stoichiometric networks is considered. The results are presented as a generalization of Metabolic Control Analysis, which has been concerned primarily with system sensitivities at steady state. An expression for time-varying sensitivity coefficients is given, and the Summation and Connectivity Theorems are generalized. The r

Michal Demetrian

We define 1+1 dimensional de Sitter manifold in this paper and we consider various coordinate systems on it. Some interesting aspects of the general theory of relativity are demonstrated by using the transformations between the considered coordinate systems. The problem might be of interest for physics and mathematics students as well as for physics teachers

Sergei A. Voloshin

Recent results on event-by-event mean transverse momentum, $\mpt$, fluctuations in ultra-relativistic heavy ion collisions are briefly reviewed. We conclude that the observed fluctuations are in a rough agreement with that expected for the independent superposition of nucleon-nucleon collisions. We further discuss the possibility of the use of the forth orde