April 2001 arXiv papers — page 13

C. D. Froggatt, H. B. Nielsen, Y. Takanishi

We have studied imposing the condition that the Standard Model effective Higgs potential should have two approximately degenerate vacua, such that the vacuum we live in is just barely metastable: the one in which we live has a vacuum expectation value of 246 GeV and the other one should have a vacuum expectation value of order the Planck scale. Alone borderl

Yukinori Nagatani

We show that a spherical electroweak domain wall is formed around a small black hole and this is a general property of the Hawking radiation in the vacuum of the Standard Model. The wall appears not only for the first order phase transition in the electroweak theory but also for the second order one because the black hole heats up its neighborhood locally by

Sasa Prelovsek

We explore the sensitivity of the flavour changing neutral currents among c and u quarks in the context of the Minimal Supersymmetric Standard Model. The standard model rate for c->u gamma can be enhanced by up to two orders of magnitudes in general MSSM, while the c->ul^+l^- rate can be enhanced by at most a factor of three. The most suitable hadronic obser

Masud Chaichian, Archil. B. Kobakhidze

In higher-dimensional theories such as Brane World models with quasi-localized non-Abelian gauge fields the vacuum structure turns out to be trivial. Since the gauge theory behaves at large distances as a $4+δ$-dimensional and thus the topology of the infinity is that of of $S^{3+δ}$ rather than $S^{3}$, the set of gauge mappings are homotopically trivial an

D. London, N. Sinha, R. Sinha

We describe a new method for extracting weak, CP-violating phase information, with no hadronic uncertainties, from an angular analysis of B -> V_1 V_2 decays, where V_1 and V_2 are vector mesons. The quantity $\sin^2 (2 ϕ_1 + ϕ_3)$ (ϕ_1=βand ϕ_3=γ) can be cleanly obtained from the study of decays such as B_d^0(t) -> D^{*\pm} ρ^\mp, D^{*\pm} a_1^{\mp}, D^{*0}

P. Ko

I report our recent works on the effects of % flavor conserving CP violating phases in SUSY models on B and K phenomenology.

B. Z. Kopeliovich, J. Raufeisen, A. V. Tarasov

In the target rest frame and at high energies, Drell-Yan (DY) dilepton production looks like bremsstrahlung of massive photons, rather than parton annihilation. The projectile quark is decomposed into a series of Fock states. Configurations with fixed transverse separations are interaction eigenstates for pp scattering. The DY cross section can then be expre

D. Monderen

We have studied [1] flavor neutrinos confined to our four-dimensional world coupled to one "bulk" state, i.e., a Kaluza-Klein tower. Within a minimal model, we accomodate existing experimental constraints (CHOOZ experiment, solar and atmospheric data). No direct flavor oscillations nor MWS effects are needed. An energy independent suppression is prod

David H. Lyth, Hang Bae Kim

This paper has been withdrawn because the analytic estimates are not confirmed by the numerical calculation of Nilles, Peloso and Sorbo (hep-ph/0102264 and hep-th/0103202).

T. Hadig

This article summarizes a talk presented at the SLAC Summer Institute 2000, SLAC, Stanford, USA. The HERA ep collider allows the measurement of the proton structure and tests of the Standard Model in a large region of phase space that has not been accessible before. Such tests provide the framework for the H1 and ZEUS Collaborations to look for physics beyon

K. Abe

We report measurements of the branching fractions for $B^0\toπ^+π^-$, $K^+π^-$, $K^+K^-$ and $K^0π^0$, and $B^+\toπ^+π^0$, $K^+π^0$, $K^0π^+$ and $K^+\bar{K}{}^0$. The results are based on 10.4 fb$^{-1}$ of data collected on the $Υ$(4S) resonance at the KEKB $e^+e^-$ storage ring with the Belle detector, equipped with a high momentum particle identification

Ntina Savvidou

We show that the relativistic analogue of the two types of time translation in a non-relativistic history theory is the existence of two distinct Poincar\'{e} groups. The `internal' Poincar\'{e} group is analogous to the one that arises in the standard canonical quantisation scheme; the `external' Poincar\'{e} group is similar to the group that arises in a L

Salvatore Capozziello, Salvatore De Martino, Silvio De Siena, Fabrizio Illuminati

We show that the characteristic sizes of astrophysical and cosmological structures, where gravity is the only overall relevant interaction assembling the system, have a phenomenological relation to the microscopic scales whose order of magnitude is essentially ruled by the Compton wavelength of the proton. This result agrees with the absence of screening mec

Madhavan Varadarajan

The quantum theory of U(1) connections admits a diffeomorphism invariant representation in which the electric flux through any surface is quantized. This representation is the analog of the representation of quantum SU(2) theory used in loop quantum gravity. We investigate the relation between this representation, in which the basic excitations are `polymer-

T. Dereli, R. W. Tucker

We argue that the geodesic hypothesis based on the autoparalllels of the Levi-Civita connection may need refinement in the scalar- tensor theories of gravity. Based on a reformulation of the Brans- Dicke theory in terms of a connection with torsion determined dynamically in terms of the gradient of the Brans-Dicke scalar field, we compute the perihelion shif

Patrick B. Warren

Late-stage coarsening in off-critical vapour-liquid phase separation is re-examined. In the limit of bubbles of vapour distributed throughout a continuous liquid phase, it is argued that coarsening proceeds via inertial hydrodynamic bubble collapse. This replaces the Lifshitz-Slyozov-Wagner mechanism seen in binary liquid mixtures. The arguments are strongly

Aki-Hiro Sato, Hideki Takayasu

A model of fluctuations in the market price including many deterministic dealers, who predict their buying and selling prices from the latest price change, is developed. We show that price changes of the model is approximated by ARCH(1) process. We conclude that predictions of dealers affected by the past price changes cause the fat tails of probability dens

A. Zheludev, Z. Honda, K. katsumata, R. feyerherm

High-field neutron diffraction studies of the new quantum-disordered S=1 linear-chain antiferromagnet Ni(C$_5$H$_{14}$N$_2$)$_2$N$_3$(ClO$_4$) (NDMAZ) are reported. At T=70 mK, at a critical field $H_c=13.4$ T applied along the (013) direction, a phase transition to a commensurate Néel-like ordered state is observed. The results are discussed in the context

Dmitri S. Golubev, Andrei D. Zaikin

We analyze an interplay between Coulomb blockade and quantum fluctuations in a coherent conductor (with dimensionless conductance $g \gtrsim 1$) attached to an Ohmic shunt. We demonstrate that at T=0 the system can be either an insulator or a metal depending on whether its total resistance is larger or smaller than $h/e^2\approx 25.8$ k$Ω$. In a metallic pha

H Y Zhai, H M Christen, L Zhang, M Paranthaman

The effect of water exposure on MgB2 is studied by submerging an 800 nm thick MgB2 film into deionized water at room temperature for 1 hour, 4 hours, 10 hours, and 15 hours, and by analyzing the resulting material using scanning electron microscopy and resistance vs. temperature measurements. It is clearly observed that Tconset of these films (obtained by an

P. Ravindran, H. Fjellvåg, A. Kjekshus, P. Blaha

The electronic structure of the perovskite La$_{1-x}$Sr$_x$CoO$_3$ has been obtained as a function of Sr substitution and volume from a series of generalized-gradient-corrected, full-potential, spin-density-functional band structure calculations. The energetics of different spin configurations are estimated using the fixed-spin-moment (FSM) method. From the

Oliver Muelken, Heinrich Stamerjohanns, Peter Borrmann

The identification and classification of phases in small systems, e.g. nuclei, social and financial networks, clusters, and biological systems, where the traditional definitions of phase transitions are not applicable, is important to obtain a deeper understanding of the phenomena observed in such systems. Within a simple statistical model we investigate the

Ingve Simonsen, Kim Sneppen

We consider a financial market where the asset price follows a fractional Brownian motion. We introduce a family of investment strategies, and quantify profit possibilities for both persistent and antipersistant markets.

Bernd Rinn, Philipp Maass, Jean-Philippe Bouchaud

Aging dynamics in glassy systems is investigated by considering the hopping motion in a rugged energy landscape whose deep minima are characterized by an exponential density of states. In particular we explore the behavior of a generic two-time correlation function Pi(t_w+t,t_w) below the glass transition temperature T_g when both the observation time t and

B. Lorenz, R. L. Meng, C. W. Chu

The pressure effect on the superconducting transition temperature of MgB2 has been determined using gas pressure up to 1 GPa. The transition temperature Tc was found to decrease linearly at a constant rate over the whole pressure range. The recently observed dramatic decrease of dTc/dp at the 40 K freezing pressure (0.5 GPa) cannot be confirmed. The pressure

I. V. Kotov, M. V. Khazimullin, A. P. Krekhov

The stability of the equilibrium configurations of a nematic liquid crystal confined between two coaxial cylinders is analysed when a radial electric field is applied and the flexoelectric effect is taken into account. The threshold for perturbations depending only on the radius r in the cylindrical coordinate system and strong boundary conditions is studied

I. Sh. Nasibullayev, A. P. Krekhov, M. V. Khazimullin

We analyse the influence of a surface viscosity on the orientational dynamics of a nematic liquid crystal subjected to an oscillatory Couette flow. Approximate analytical solutions of nematohydrodynamic equations for small flow amplitudes are calculated and compared with the results of full numerical simulations. The range of flow frequencies where the surfa

H. -B. Schüttler, C. Gröber, H. G. Evertz, W. Hanke

By combining fermion Quantum Monte Carlo (QMC) simulations with diagrammatic theory, we have calculated the dielectric screening and the screened potential, in a quasi 2D Hubbard model for cuprate superconductors with and without 1/r Coulomb potential. At half filling, we find that the Hubbard electrons contribute only a minor fraction, Delta(epsilon) ~0.9 o

Walter Hofstetter

Wilson's Numerical Renormalization Group (NRG) is so far the only nonperturbative technique that can reliably access low-energy properties of quantum impurity systems. We present a recent extension of the method, the DM-NRG, which yields highly accurate results for dynamical quantities at arbitrary frequencies and temperatures. As an application, we dete

Olaf Stenull, Hans-Karl Janssen

We study resistor diode percolation at the transition from the non-percolating to the directed percolating phase. We derive a field theoretic Hamiltonian which describes not only geometric aspects of directed percolation clusters but also their electric transport properties. By employing renormalization group methods we determine the average two-port resista

A. A. Kordyuk, S. V. Borisenko, M. S. Golden, S. Legner

A detailed and systematic ARPES investigation of the doping-dependence of the normal state Fermi surface (FS) of modulation-free (Pb,Bi)-2212 is presented. The FS does not change in topology away from hole-like at any stage. The data reveal, in addition, a number of surprises. Firstly the FS area does not follow the usual curve describing Tc vs x for the hol

H. -J. Schmidt, J. Schnack

We find a close correspondence between certain partition functions of ideal quantum gases and certain symmetric polynomials. Due to this correspondence it can be shown that a number of thermodynamic identities which have recently been considered are essentially of combinatorical origin and known for a long time as theorems on symmetric polynomials. For examp

L. Šamaj, B. Jancovici

The model under consideration is a two-dimensional two-component plasma, i.e., a continuous system of two species of pointlike particles of opposite charges $\pm 1$, interacting through the logarithmic Coulomb interaction. Using the exact results for the form-factors of an equivalent Euclidean sine-Gordon theory, we derive the large-distance behavior of the

A. V. Pronin, A. Pimenov, A. Loidl, S. I. Krasnosvobodtsev

The complex conductivity of a MgB2 film has been investigated in the frequency range 4 cm^{-1}< nu < 30 cm^{-1} and for temperatures 2.7 K < T <300 K. The overall temperature dependence of both components of the complex conductivity is reminiscent of BCS-type behavior, although a detailed analysis reveals a number of discrepancies. No characteristic feature

M. V. Khazimullin, A. P. Krekhov, Yu. A. Lebedev

The temperature behaviour of the anchoring energy of nematic liquid crystal MBBA at the substrates with oblique SiO evaporation and director orientation at the interface have been studied by means of magnetic Freedericksz transition technique. The temperature dependence of the coefficients in the phenomenological model of surface anchoring energy has been de

K. Ohwada, Y. Fujii, N. Takesue, M. Isobe

The &#34;devil&#39;s staircase&#34; type phase transition in the quarter-filled spin-ladder compound NaV2O5 has been discovered at low temperature and high pressure by synchrotron radiation x-ray diffraction. A large number of transitions are found to successively take place among higher-order commensurate phases with 2a * 2b * zc type superstructures. The o

Dingping Li, Baruch Rosenstein

A new systematic calculation of magnetization and specific heat contributions of vortex liquids and solids (not very close to the melting line) is presented. We develop an optimized perturbation theory for the Ginzburg - Landau description of thermal fluctuations effects in the vortex liquids. The expansion is convergent in contrast to the conventional high

E. Bauer, Ch. Paul, St. Berger, S. Majumdar

Thermal conductivity of superconducting MgB2 was studied in both the superconducting and the normal state region. The latter is almost equally determined by the electronic - and the lattice contribution to the total thermal conductivity. In the superconducting state, however, the lattice contribution is larger. The electronic thermal conductivity below Tc wa

R. K. Kremer, B. J. Gibson, K. Ahn

We characterize the superconducting state of phase pure polycrystalline samples of the new layered superconductor MgB$_2$ by specific heat measurements in magnetic fields up to 9 T. The characteristic jump at the superconducting transition is observed and compared with the predictions of weak coupling BCS-theory and the $α$-model. Our analysis shows excellen

L. Leuzzi, G. Parisi

We compute the thermodynamic properties of the 3-satisfiability problem in the infinite connectivity limit. In this limit the computations can be strongly simplified and the thermodynamical properties can be obtained with an high accuracy. We find evidence for a continuous replica symmetry breaking in the region of high number of clauses, $α> α_c$.

B. R. Oppenheimer, N. C. Hambly, A. P. Digby, S. T. Hodgkin

The Milky Way Galaxy contains a large, spherical component which is believed to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this ``dark matter'' may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the Galaxy itself. We conducted a survey t

Guenter Sigl

The origin of cosmic rays is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely associated with the most energetic processes in the Universe. They thus provide a probe of physics and astrophysics at energies that are unreached in laboratory expe

Massimo Giovannini

It is shown that the evolution of the (Abelian) gauge coupling during an inflationary phase of de Sitter type drives the growth of the two-point function of the magnetic inhomogeneities. After examining the constraints on the variation of the gauge coupling arising in a standard model of inflationary and post-inflationary evolution, magnetohydrodynamical equ

C. Isola, M. Lemoine, G. Sigl

We present numerical simulations for energy spectra and angular distributions of nucleons above 10^{19} eV injected by the radio-galaxy Centaurus A at a distance 3.4 Mpc and propagating in extra-galactic magnetic fields in the sub-micro Gauss range. We show that field strengths B~0.3 micro Gauss, as proposed by Farrar and Piran, cannot provide sufficient ang

G. P. Rowell, HEGRA Collaboration

The HEGRA CT-System was used to search for TeV gamma-rays from the microquasar and supernova remnant combination SS-433/W50 over the 1998 and 1999 observing seasons, resulting in about 20 hours of useful data. An analysis of various extended sources of location guided by X-Ray observations reveals no evidence for TeV emission at photon energies above 1 TeV,

R. A. Jansen, S. J. Kannappan

We report on our observing program to obtain integrated spectrophotometry, intermediate and high resolution major axis spectra, and U,B,R surface photo- metry of a representative sample of ~200 galaxies in the nearby field. The main goal of this program is to provide a comparison sample for high redshift studies and to study the variation in star formation r

J. J. M. in &#39;t Zand, R. Cornelisse, E. Kuulkers, J. Heise

Data of the 1996 outburst of the single-known accreting millisecond pulsar SAX J1808.4-3658, taken with the Wide Field Cameras (WFCs) on BeppoSAX, are revisited with more complete data coverage and more comprehensive analysis techniques than in a previous report. An additional type-I X-ray burst was identified which occurred at a time when the persistent emi

G. Schatz

28 size spectra of extensive air showers from 7 different experiments are analysed consistently. They are fitted by adjusting either 4 or 5 parameters: knee position, power law exponents above and below the knee, overall intensity and, in addition, a parameter describing the smoothness of the bend. The residuals are then normalized to the same knee position

Stefanie Komossa

NGC 4151 is one of the brightest and best-studied Seyfert galaxies. Here, we present a two-phase model of the narrow-line region (NLR) of NGC 4151. This study is motivated by (i) the fact that the X-ray spectrum of NGC 4151 is among the flattest known for Seyferts, and (ii) the recent Chandra detection of an X-ray narrow-line region in this galaxy. X-ray spe

Robert H. Becker, Richard L. White, Michael D. Gregg, Sally A. Laurent-Muehleisen

We present the results of an extension of the FIRST Bright Quasar Survey (FBQS) to the South Galactic cap, and to a fainter optical magnitude limit. Radio source counterparts with SERC R magnitudes brighter than 18.9 which meet the other FBQS criteria are included. We supplement this list with a modest number of additional objects to test our completeness fo

M. Landgraf, R. Jehn, N. Altobelli, V. Dikarev

The ESA meteoroid model predicts impacts of meteoroids in the mass range between $10^{-18}$ to $10^0$ g on spacecraft surfaces. It covers heliocentric distances from 0.3 to 20 AU. Measurements of the dust detector on board the highly successful joint ESA/NASA mission Ulysses have shown, that the flux of meteoroids with masses between $10^{-15}$ and $10^{-12}

M. Landgraf, R. Jehn

The collinear Lagrange points of the Sun-Earth system provide an ideal environment for highly sensitive space science missions. Consequently many new missions are planed by ESA and NASA that require satellites close to these points. For example, the SOHO spacecraft built by ESA is already installed in the first collinear Lagrange point. Neither uncontrolled

C. Abia, I. Dominguez, O. Straniero, M. Limongi

Motivated by the recent detection of metals in different components of the high redshift universe and by the abundance ratios measured in the extremely metal-poor stars of our Galaxy, we study the nucleosynthesis constraints that this imposes on an early generation of stars (Population III). To do so we take into account the chemical yields obtained from hom

Timothy C. Beers, Masashi Chiba

We present a review of recent studies of the formation and evolution of the Milky Way galaxy, in particular based on large samples of non-kinematically selected stars with available proper motions. The Milky Way is argued to be a reasonable template for the formation of large spiral galaxies, the only one in which complete kinematical and abundance informati

Wolfgang Brandner, Eva K. Grebel, Rodolfo H. Barba, Nolan R. Walborn

We present the detection of an intermediate-mass pre-main-sequence population embedded in the nebular filaments surrounding the 30 Doradus region in the Large Magellanic Cloud (LMC) using HST/NICMOS. In addition to four previously known luminous Class I infrared ``protostars,&#39;&#39; the NICMOS data reveal 20 new sources with intrinsic infrared excess simi

Julien Malzac

We study a phenomenological model for the continuum emission of Seyfert galaxies. In this quasi-spherical accretion scenario, the central X-ray source is constituted by a hot spherical plasma region surrounded by spherically distributed cold dense clouds. The cold material is radiatively coupled with the hot thermal plasma. Assuming energy balance, we comput

J. Xu, R. L. B. Selinger, J. V. Selinger, R. Shashidhar

We carry out Monte Carlo simulations to investigate the effect of molecular shape on liquid-crystal order. In our approach, each model mesogen consists of several soft spheres bonded rigidly together. The arrangement of the spheres may be straight (to represent uniaxial molecules), Z-shaped (for biaxial molecules), or banana-shaped (for bent-core molecules).

Jorge Alfaro, Pedro Labraña

We study the properties of a non-abelian gauge theory subjected to a gauge invariant constraint given by the classical equations of motion. The constraint is not imposed by hand, but appears naturally when we study a particular type of local gauge transformations. In this way, all standard techniques to treat gauge theories are available. We will show that t

Eytan Domany, Guy Hed, Matteo Palassini, A. P. Young

We generate equilibrium configurations for the three and four dimensional Ising spin glass with Gaussian distributed couplings at temperatures well below the transition temperature T_c. These states are analyzed by a recently proposed method using clustering. The analysis reveals a hierarchical state space structure. At each level of the hierarchy states are

Craig J. Hogan, Peter L. Bender

Armstrong et al. have recently presented new ways of combining signals to precisely cancel laser frequency noise in spaceborne interferometric gravitational wave detectors such as LISA. One of these combinations, the symmetrized Sagnac observable, is much less sensitive to external signals at low frequencies than other combinations, and thus can be used to d

Eloy Ayón-Beato, Alberto García, Alfredo Macías, Hernando Quevedo

We investigate spherically symmetric and static gravitational fields representing black hole configurations in the framework of metric-affine gauge theories of gravity (MAG) in the presence of different matter fields. It is shown that in the triplet ansatz sector of MAG, black hole configurations in the presence of non-Abelian matter fields allow the existen

Beverly K. Berger, James Isenberg, Marsha Weaver

We use qualitative arguments combined with numerical simulations to argue that, in the approach to the singularity in a vacuum solution of Einstein&#39;s equations with $T^2$ isometry, the evolution at a generic point in space is an endless succession of Kasner epochs, punctuated by bounces in which either a curvature term or a twist term becomes important i

K. D. Sviratcheva, A. I. Georgieva, V. G. Gueorguiev, J. P. Draayer

With a view towards future applications in nuclear physics, the fermion realization of the compact symplectic sp(4) algebra and its q-deformed versions are investigated. Three important reduction chains of the sp(4) algebra are explored in both the classical and deformed cases. The deformed realizations are based on distinct deformations of the fermion creat

Tianjun Li

We conjecture that the extra dimensions are physical non-compact at high energy scale or high temperature; after the symmetry breaking or cosmological phase transition, the bulk cosmological constant may become negative, and then, the extra dimensions may become physical compact at low energy scale. We show this in a five-dimensional toy brane model with thr

Han Pu, Weiping Zhang, Martin Wilkens, Pierre Meystre

We calculate the phonon excitation spectrum in a zero-temperature boson-fermion mixture. We show how the sound velocity changes due to the boson-fermion interaction and we determine the dynamical stability regime of a homogeneous mixture. We identify a resonant phonon-exchange interaction between the fermions as the physical mechanism leading to the instabil

V. A. Rubakov

The emphasis in the developmet of theories with more than three spatial dimensions has recently shifted towards ``brane world&#39;&#39; picture, which assumes that ordinary matter (with possible exceptions of gravitons and other, hypothetic, particles which interact very weakly with matter) is trapped to a three-dimensional submanifold --- brane --- embedded

Karl Landsteiner, Esperanza Lopez, Michel H. G. Tytgat

We extend our previous work on the quasi-particle excitations in N=4 non-commutative U(1) Yang-Mills theory at finite temperature. We show that above some critical temperature there is a tachyon in the spectrum of excitations. It is a collective transverse photon mode polarized in the non-commutative plane. Thus the theory seems to undergo a phase transition

Chuan-Hung Chen, C. Q. Geng

We study the contribution of a generic charged Higgs $(H^+)$ to the muon anomalous magnetic moment $a_μ$ with the SUSY soft breaking parameters. We find out that the deviation between the experimental data and the predicted SM value on $a_μ$ can be explained by the two-loop charged Higgs diagrams even with $m_{H^+}\sim 400 GeV$.

Gordon Chalmers

The strongly coupled limit of string scattering and the automorphic construction of the graviton S-matrix is compared with the eleven dimensional formulation of M-theory. In a particular scaling limit at strong string coupling, M-theory is described by eleven-dimensional supergravity which does not possess a dilaton, but rather a perturbative expansion in th

France Allard, Peter H. Hauschildt, David R. Alexander, Akemi Tamanai

We present opacity sampling model atmospheres, synthetic spectra and colors for brown dwarfs and very low mass stars in two limiting case of dust grain formation: 1) inefficient gravitational settling i.e. the dust is distributed according to the chemical equilibrium predictions, 2) efficient gravitational settling i.e. the dust forms and depletes refractory

G. S. Japaridze

Space of states of PT symmetrical quantum mechanics is examined. Requirement that eigenstates with different eigenvalues must be orthogonal leads to the conclusion that eigenfunctions belong to the space with an indefinite metric. The self consistent expressions for the probability amplitude and average value of operator are suggested. Further specification

Christian Schoen, Almut Beige

To investigate the effect of a classical environment on a quantum mechanical system we consider two two-level atoms in a free radiation field in the presence of a screen. By assuming that the screen causes continuous ideal measurements on the free radiation field we derive a quantum jump description for the state of the atoms. Our results are consistent with

Kentaro Nomura, Daijiro Yoshioka

The effects of randomness are investigated in the fractional quantum Hall systems. Based on the Chern-Simons Ginzburg-Landou theory and considering relevant quasi-particle tunneling, the edge state network model for the hierarchical state is introduced and the plateau-plateau transition and liquid-insulator transition are discussed. This model has duality wh

W. N. Kang, Hyeong-Jin Kim, Eun-Mi Choi, C. U. Jung

We report the growth of high-quality c-axis-oriented epitaxial MgB2 thin films by using a pulsed laser deposition technique. The thin films grown on (1`1 0 2) Al2O3 substrates show a Tc of 39 K. The critical current density in zero field is ~ 6 x 10^6 A/cm2 at 5 K and ~ 3 x 10^5 A/cm^2 at 35 K, suggesting that this compound has great potential for electronic

Geraint F. Lewis, Rodrigo A. Ibata

The quest for the cosmological parameters has come to fruition with the identification of a number of supernovae at a redshift of $z\sim1$. Analyses of the brightness of these standard candles reveal that the Universe is dominated by a large cosmological constant. The recent identification of the $z\sim1.7$ SN1997ff in the northern Hubble Deep Field has prov

Tomoyuki Fujita, Keisuke Ohashi

We present a full superconformal tensor calculus in five spacetime dimensions in which the Weyl multiplet has 32 Bose plus 32 Fermi degrees of freedom. It is derived by the dimensional reduction from the 6D superconformal tensor calculus. We present two types of 32+32 Weyl multiplets, vector multiplet, linear multiplet, hypermultiplet and nonlinear multiplet

The Cloud Collaboration

Recent satellite data have revealed a surprising correlation between galactic cosmic ray (GCR) intensity and the fraction of the Earth covered by clouds. If this correlation were to be established by a causal mechanism, it could provide a crucial step in understanding the long-sought mechanism connecting solar and climate variability. The Earth&#39;s climate

Do Minh Chi

We advance a famous principle - causality principle - but under a new view. This principle is a principium automatically leading to most fundamental laws of the nature. It is the inner origin of variation, rules evolutionary processes of things, and the answer of the quest for ultimate theories of the Universe.

M. Baldo, U. Lombardo, E. E. Saperstein, M. V. Zverev

The Brueckner G-matrix for a slab of nuclear matter is analyzed in the singlet $^1S$ and triplet $^3S+^3D$ channels. The complete Hilbert space is split into two domains, the model subspace $S_0$, in which the two-particle propagator is calculated explicitly, and the complementary one, $S&#39;$, in which the local potential approximation is used. This kind o

C. Chevallard, M. G. Clerc, P. Coullet, J. -M. Gill

We present a theoretical explanation for the interfacial zigzag instability that appears in anisotropic systems. Such an instability has been experimentally highlighted for an Ising wall formed in a nematic liquid crystal cell under homeotropic anchoring conditions. From an envelope equation, relevant close to the Freedericksz transition, we have derived an

Eric Sommers

We present a new characterization of Lusztig&#39;s canonical quotient group. We also define a duality map: to a pair consisting of a nilpotent orbit and a conjugacy class in its fundamental group, the map assigns a nilpotent orbit in the Langlands dual Lie algebra.

Jason Fulman

Using the Berele/Remmel/Kerov/Vershik variation of the Robinson-Schensted-Knuth correspondence, we study the cycle and increasing subsequence structure after various methods of shuffling. One consequence is a cycle index for shuffles like: cut a deck into roughly two equal piles, thoroughly mix the first pile and then riffle it with the second pile. Conclusi

Michael Gutperle, Andrew Strominger

A flux p-brane in D dimensions has (p+1)-dimensional Poincare invariance and a nonzero rank (D-p-1) field strength tangent to the transverse dimensions. We find a family of such solutions in string theory and M-theory and investigate their properties.

Itzhak Bars, Soo-Jong Rey

Phase-space and its relativistic extension is a natural space for realizing Sp(2,R) symmetry through canonical transformations. On a Dx2 dimensional covariant phase-space, we formulate noncommutative field theories, where Sp(2,R) plays a role as either a global or a gauge symmetry group. In both cases these field theories have potential applications, includi

Christof Schmidhuber

It has recently been argued that non--BPS brane world scenarios can reproduce the small value of the cosmological constant that seems to have been measured. Objections against this proposal are discussed and necessary (but not sufficient) conditions are stated under which it may work. At least n=2 extra dimensions are needed. Also, the mass matrix in the sup

Stanley J. Brodsky

Exclusive B decays can be factorized as convolutions of hard scattering amplitudes involving the weak interaction with universal hadron distribution amplitudes, thus providing a new QCD-based phenomenology. In addition, semi-leptonic decay amplitudes can be computed exactly in terms of the diagonal and off-diagonal overlap of hadronic light-cone wavefunction

Hoang Ngoc Long, Dang Van Soa

The trilinear gauge boson couplings in the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1) models are presented. We find that new $Z_2$ does not interact with the usual (in the standard model) gauge bosons $Z, W^\pm$. Based on these results, production of new heavy gauge bosons at high energy colliders such as e^+ e^- is calculated. We show that the cross sections ob

Boris Kayser

Do neutrinos have nonzero masses? If they do, then these masses are very tiny, and can be sought only in very sensitive experiments. The most sensitive of these search for neutrino oscillation, a quantum interference effect which requires neutrino mass and leptonic mixing. In these lectures, we explain what leptonic mixing is, and then develop the physics of

Seungwon Baek, Toru Goto, Yasuhiro Okada, Ken-ichi Okumura

Motivated by the large mixing angle solutions for the atmospheric and solar neutrino anomalies, flavor changing neutral current processes and lepton flavor violating processes as well as the muon anomalous magnetic moment are analyzed in the framework of SU(5) SUSY GUT with right-handed neutrino. In order to explain realistic mass relations for quarks and le

Tetsuo Hatsuda

After a brief summary of the QCD phase structure with light quarks, we discuss two recent developments on in-medium hadrons. First topic is the sigma-meson which is a fluctuation of the chiral order parameter \bar{q}q. Although sigma is at best a broad resonance in the vacuum, it may suffer a substantial red-shift and show a characteristic spectral enhanceme

NuTeV Collaboration, J. A. Formaggio, J. Yu

The NuTeV experiment at Fermilab has used a sign-selected neutrino beam to perform a search for the lepton number violating process nu_mu-bar e^- -> mu^- nu_e-bar, and to measure the cross-section of the Standard Model inverse muon decay process nu_mu e^- -> mu^- nu_e. NuTeV measures the inverse muon decay asymptotic cross-section sigma/E to be 13.8 +/- 1.2

Gang Lu, Qing Zhang, Nicholas Kioussis, Efthimios Kaxiras

Dislocation core properties of Al with and without H impurities are studied using the Peierls-Nabarro model with parameters determined by ab initio calculations. We find that H not only facilitates dislocation emission from the crack tip but also enhances dislocation mobility dramatically, leading to macroscopically softening and thinning of the material ahe

Xin Wan, R. N. Bhatt

Recent experiments in the integer quantum Hall regime seem to find direct transitions from a quantum Hall state with Hall conductance $σ_{xy} = n e^2/h $ with integer $n > 1$, to an insulating state in weak magnetic fields. We study this issue using a variation of the tight-binding lattice model for non-interacting electrons. Although quantum Hall transition

Paal Erik Goa, Harald Hauglin, Michael Baziljevich, Eugene Il&#39;yashenko

We demonstrate here real-time imaging of individual vortices in a NbSe2 single crystal using polarized light microscopy. A new high-sensitivity magneto-optical (MO) imaging system enables observation of the static vortex lattice as well as single vortex motion at low flux densities.

V. I. Yukalov, E. P. Yukalova

Superradiance of nuclear spins is considered, when the nuclei interact via hyperfine forces with electrons of a ferromagnet. The consideration is based on a microscopic model. If the sample, coupled with a resonant electric circuit, possesses electronic magnetization, then the electron subsystem plays the role of an additional effective resonator, by enhanci

S. Basak, I. Chaudhuri, S. K. Ghatak

The effect of strain on the resistivity and thermopower of ferromagnetic manganites has been examined based on the model that incorporates the electron-lattice interaction through the Jahn-Teller effect and an effective hopping determined by nearest neighbour spin-spin correlation of t2g electrons. The metal insulator transition temperature associated with r

Hiroaki Kusunose, Yoshio Kuramoto

Elementary excitations in the multipole ordered state, which models the phase III in CeB6, are investigated by means of a generalized Holstein-Primakoff formalism. When different kinds of nearest-neighbor exchange interactions between multipoles are comparable to each other, orbital-flip excitations exhibit almost one-dimensional dispersion along the z axis.

Hiroaki Kusunose, Yoshio Kuramoto

The origin of non-collinear magnetism under quadrupolar ordering is investigated with CeB6 taken as a target system. The mode-mixing effect among 15 multipoles is analyzed based on the Ginzburg-Landau free energy. Then the lower magnetic transition temperature and the order parameters are derived within the mean-field approximation. In the presence of pseudo

Martin A. Guerrero, You-Hua Chu, Robert A. Gruendl, Rosa M. Williams

Recent Chandra ACIS-S observations have detected a point source at the central star of NGC 6543 and confirmed the point source nature of the hard X-ray emission from NGC 7293. The X-ray spectra of both sources peak between 0.5 keV and 1.0 keV and show line features indicating a thin plasma at temperatures of a few times 10^6 K. Their X-ray luminosities are 1

Robert A. Gruendl, You-Hua Chu, Ian J. O&#39;Dwyer, Martin A. Guerrero

The central star of the Helix Nebula is a hot white dwarf with unexpected hard X-ray emission. With an effective temperature of ~100,000 K, the star is a powerful source of H-ionizing radiation; the atmosphere of a stellar or planetary companion, if present, will be ionized and emit recombination lines. To probe the origin of hard X-ray emission from the Hel