February 2001 arXiv papers — page 10

J. Mesot, M. Boehm, M. R. Norman, M. Randeria

We report the first inelastic neutron scattering (INS) experiments of the resonance in the underdoped regime of Bi2Sr2CaCu2O8+d. The energy of the resonance is found to be 34 meV and the temperature dependence shows a smooth evolution through Tc with a remnant persisting in the pseudogap state. Besides the INS data, we present also angle resolved photoemissi

F. Piazza, E. Abraham, L. Cianchi, F. Del Giallo

We report temperature-dependent Moessbauer and EXAFS measurements of atomic mean square displacements on different samples of EuBCO. Our results indicate that the collective atomic motions are characterised by large-amplitude anharmonic oscillations.

A. P. Vieira, J. X. de Carvalho, S. R. Salinas

We investigate the phase diagram of a mixed spin-1/2--spin-1 Ising system in the presence of quenched disordered anisotropy. We carry out a mean-field and a standard self-consistent Bethe--Peierls calculation. Depending on the amount of disorder, there appear novel transition lines and multicritical points. Also, we report some connections with a percolation

H. Kotegawa, K. Ishida, Y. Kitaoka, T. Muranaka

We have investigated a gap structure in a newly-discovered superconductor, MgB2 through the measurement of 11B nuclear spin-lattice relaxation rate, ^{11}(1/T_1). ^{11}(1/T_1) is proportional to the temperature (T) in the normal state, and decreases exponentially in the superconducting (SC) state, revealing a tiny coherence peak just below T_c. The T depende

Mitsuhiro Arikawa, Yasuhiro Saiga, Yoshio Kuramoto

The electron addition spectrum A^+(k,omega) is obtained analytically for the one-dimensional (1D) supersymmetric t-J model with 1/r^2 interaction. The result is obtained first for a small-sized system and its validity is checked against the numerical calculation. Then the general expression is found which is valid for arbitrary size of the system. The thermo

L. Šamaj

We consider a one-dimensional continuum gas of pointlike positive and negative unit charges interacting via a logarithmic potential. The mapping onto a two-dimensional boundary sine-Gordon field theory with zero bulk mass provides the full thermodynamics (density-fugacity relationship, specific heat, etc.) of the log-gas in the whole stability range of inver

M. Potthoff, T. Wegner, W. Nolting, T. Schlathölter

Spin-resolved and temperature-dependent appearance-potential spectra of ferromagnetic Nickel are measured and analyzed theoretically. The Lander self-convolution model which relates the line shape to the unoccupied part of the local density of states turns out to be insufficient. Electron correlations and orbitally resolved transition-matrix elements are sho

Gene F. Mazenko

The statistical correlations between defects in the two dimensional complex Ginsburg-Landau model are studied in the defect-coarsening regime. In particular the defect-velocity probability distribution is determined and has the same high velocity tail found for the purely dissipative time-dependent Ginsburg-Landau (TDGL) model. The spiral arms of the defects

Audun Bakk, Johan S. Hoye, Alex Hansen

We construct a Hamiltonian for a single domain protein where the contact enthalpy and the chain entropy decrease linearly with the number of native contacts. The hydration effect upon protein unfolding is included by modeling water as ideal dipoles that are ordered around the unfolded surfaces, where the influence of these surfaces, covered with an ``ice-lik

Julien Barre, Thierry Dauxois

We study analytically the behavior of the largest Lyapunov exponent $λ_1$ for a one-dimensional chain of coupled nonlinear oscillators, by combining the transfer integral method and a Riemannian geometry approach. We apply the results to a simple model, proposed for the DNA denaturation, which emphasizes a first order-like or second order phase transition de

Giuliano Benenti, Gaetan Caldara, Dima L. Shepelyansky

We study numerically the ground state magnetization for clusters of interacting electrons in two dimensions in the regime where the single particle wavefunctions are localized by disorder. It is found that the Coulomb interaction leads to a spontaneous ground state magnetization. For a constant electronic density, the total spin increases linearly with the n

Toru Sakai

We propose a possible mechanism of the charge stripe order due to the next-nearest neighbor exchange interaction J' in the two-dimensional t-J model, based on the concept of the phase separation. We also calculate some hole correlation functions of the finite cluster of the model using the numerical diagonalization, to examine the realization of the mech

Takuya Yamano

The channel capacity for the binary symmetric channel is investigated based on the symmetrized definition of the mutual information, which is arising from an attempt of extension of information content based on the nonadditivity. The negative capacity can emerge as an avoidable consequence for the generalization of the concept of the information entropy when

Amlan Biswas, M. Rajeswari, R. C. Srivastava, T. Venkatesan

We present evidence for the coexistence of ferromagnetic metallic and charge ordered insulating phases in strained thin films of La$_{0.67}$Ca$_{0.33}$MnO$_3$ at low temperatures. Such a phase separated state is confirmed using low temperature magnetic force microscopy and magnetotransport measurements. This phase separated state is not observed in the bulk

G. Karapetrov, M. Iavarone, W. K. Kwok, G. W. Crabtree

We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter Gamma. The value of the superconducting gap is 5.2 meV at 4.2 K, with no experimentally significant variat

Th. Siller, M. Troyer, T. M. Rice, S. R. White

We numerically investigate a bosonic representation for hole pairs on a two-leg t-J ladder where hard core bosons on a chain represent the hole pairs on the ladder. The interaction between hole pairs is obtained by fitting the density profile obtained with the effective model to the one obtained with the \tj model, taking into account the inner structure of

P. J. E. Peebles

Recent observational advances have considerably improved the cosmological tests, adding to the lines of evidence, and showing that some issues under discussion just a few years ago may now be considered resolved or irrelevant. Other issues remain, however, and await resolution before the great program of testing the relativistic Friedmann-Lemaitre model, tha

Eric D. Feigelson

Observations of nearby star forming clouds with imaging X-ray telescopes have revealed that X-ray emission is elevated $10^1-10^4$ above main sequence levels in low-mass pre-main sequence (PMS) stars. The variability and spectral X-ray evidence, together with circularly polarized radio continuum flares seen in a few cases, strongly argues for an origin in ma

Juri Poutanen

I review the temporal/spectral data of accreting black hole sources paying most attention to the properties of the temporal variability such as photon energy dependent auto- and cross-correlation functions, average shot profiles and hardness ratios, and the Fourier frequency dependent time/phase lags. These statistics characterize spectral changes at short t

Stephen Fegan

A review of very high energy gamma-ray astronomy is presented. Particular attention is paid to the atmospheric Cherenkov imaging technique whose employment has resulted in detections of both galactic and extra-galactic objects at energies above 300GeV. Next generation ground-based telescopes promise to increase our knowledge of extreme astrophysical objects

L. Pentericci, P. J. McCarthy, H. J. A. Röttgering, G. K. Miley

We present the results of a near infrared imaging program of a sample of 19 radio galaxies with redshift between 1.7 and 3.2, using the NICMOS Camera 2 on the Hubble Space Telescope. The galaxies were observed in H-band which, for 18 of the 19 targets, samples the rest-frame optical emission longwards of the 4000 A break. The images show a wide range of morp

M. Jura, R. A. Webb, C. Kahane

We have detected continuum emission at 450 microns, 850 microns and 1.35 millimeters from SS Lep (or 17 Lep), 3 Pup and probably BM Gem, likely or confirmed binary systems consisting of at least one evolved giant. The observed submillimeter fluxes are probably emitted by grains rather than ionized gas. The dust temperature is greater than 70 K within 6 arcse

Hantao Ji

It is shown that the turbulent dynamo $α$-effect converts magnetic helicity from the turbulent field to the mean field when the turbulence is electromagnetic while the magnetic helicity of the mean-field is transported across space when the turbulence is electrostatic or due to the electron diamagnetic effect. In all cases, however, the dynamo effect strictl

Francesco Sylos Labini, Luciano Pietronero

The question of the nature of galaxy clustering and the possible homogeneity of galaxy distribution is one of the fundamental problem of cosmology. It is well established that galaxy structures are characterized, up to a certain scale, by fractal properties. The possible crossover to homogeneity is instead still matter of debate. However, independently on th

Mikel Susperregi

The least-action principle (LAP) method is used on four galaxy redshift surveys to measure the density parameter Omega_m and the matter and galaxy-galaxy power spectra. The datasets are PSCz, ORS, Mark III and SFI. The LAP method is applied on the surveys simultaneously, resulting in an overconstrained dynamical system that describes the cosmic overdensities

Charles B. Leffert

Could one start from scratch, ignore relativity theory and quantum theory, create and expand our 3-D universe with no singularities, have the mathematical model predict correctly all of the cosmological parameters, provide the origins and understanding of time, energy, gravity and some of quantum behavior inside our 3-D universe and do all of that with just

Eli Waxman, Abraham Loeb

We show that as a Type II supernova shock breaks out of its progenitor star, it becomes collisionless and may accelerate protons to energies >10 TeV. Inelastic nuclear collisions of these protons produce a ~1 hr long flash of TeV neutrinos and 10 GeV photons, about 10 hr after the thermal (10 MeV) neutrino burst from the cooling neutron star. A Galactic supe

D. Pourbaix

The Hipparcos Intermediate Astrometric Data have been used lately to estimate the inclination of the orbital plane of candidate extrasolar planets. Whereas most of these investigations derive almost face-on orbits, we show that the astrometric data are seldom precise enough to undertake such studies and that the `face-on' result might be just a spurious

Tsvi Piran

Gamma Ray Bursts (GRBs) are the most relativistic objects known so far, involving, on one hand an ultra-relativistic motion with a Lorentz factor $Γ> 100$ and on the other hand an accreting newborn black hole. The two main routes leading to this scenario: binary neutron star mergers and Collapsar - the collapse of a rotating star to a black hole, are classic

J. M. Bai, Myung Gyoon Lee

In this paper, we identify Cen A and M87, two nearby Fanaroff-Riley I (FRI) radio galaxies, with high-energy-peaked BL Lac-like (HBL-like) objects by investigating their spectral energy distributions (SEDs). The SED peak of Cen A at $\sim$150 keV, which was generally believed to be the peak of inverse-Compton emission as in the case of 3C 273, is found to be

Alexander E. Dudorov, Oleg A. Kuznetsov, Andrey G. Zhilkin

The explicit quasi-monotonic conservative TVD scheme and numerical method for the solution of the gravitational MHD equations are developed. The 2D numerical code for the simulation of multidimensional selfgravitating MHD flows on the Eulerian cylindrical grid is constructed. The results of test calculations show that the code has a good mathematical and com

Sylvie F. Beaulieu, Gerard Gilmore, Rebecca A. W. Elson, Rachel A. Johnson

We present a HST study of the metal-rich globular cluster NGC6553 using WFPC2, NICMOS and STIS. Our primary motivation is to calibrate the STIS broad-band LP magnitude against $V_{555}$ and $I_{814}$ magnitudes for stars of known metallicity and absolute (visual) magnitude, for application to our study of LMC globular clusters. NGC6553 has been shown in earl

H. Noh, J. Hwang

We present the power spectra of the scalar- and tensor-type structures generated in an inflation model based on the nonminimally coupled scalar field with a self coupling. By comparing the contributions of these structures to the anisotropy of the cosmic microwave background radiation with the four year COBE DMR data we derive strong constraints on model par

B. Vandame, L. F. Olsen, H. E. Jorgensen, M. A. T. Groenewegen

This paper presents new J and Ks near-infrared data obtained from observations of the Chandra Deep Field South (CDF-S) conducted at the ESO 3.5m New Technology Telescope (NTT). These data were taken as part of the ongoing Deep Public Survey (DPS) being carried out by the ESO Imaging Survey (EIS) program, extending the EIS-DEEP survey. Combined these surveys

Chris Austin

The coefficients in the 1/N expansions of the vacuum expectation values and correlation functions of Wilson loops, in continuum SU(N) gauge theories in 3+1 dimensions, are shown to be determined by a closed and complete set of equations, called the Group-Variation Equations, that exhibit a simple and robust mechanism for the emergence of massive glueballs an

S. Catani, D. de Florian, M. Grazzini

We consider QCD corrections to Higgs boson production through gluon-gluon fusion in hadron collisions. Using the recently evaluated two-loop amplitude for this process and the corresponding factorization formulae for soft-gluon bremsstrahlung at O(alpha_s^2), we compute the soft and virtual contributions to the NNLO cross section. We also discuss soft-gluon

S. N. Gninenko, N. V. Krasnikov

It is shown that the 2.6 $σ$ discrepancy between the predicted and recently measured value of the anomalous magnetic moment of positive muons could be explained by the existence of a new light gauge boson X with a mass $M_X \leq O(5) GeV$. Phenomenological bounds on the X coupling are discussed.

M. Calixto

A physical and geometrical interpretation of previously introduced tensor operator algebras of U(2,2) in terms of algebras of higher-conformal-spin quantum fields on the anti-de Sitter space AdS_5 is provided. These are higher-dimensional W-like algebras and constitute a potential gauge guide principle towards the formulation of induced conformal gravities (

A. V. Belitsky, D. Müller

We develop a formalism for the resummation of target mass corrections in off-forward two-photon amplitudes given by a chronological product of electromagnetic currents, arising in e.g. deeply virtual Compton scattering. The method is based on a relation of composite operators with a definite twist to harmonic tensors, which form an irreducible representation

Q. Zhao, J. S. Al-Khalili, C. Bennhold

The photoproduction of $K^*$ vector mesons is investigated in a quark model with an effective Lagrangian. Including both baryon resonance excitations and {\it t}-channel exchanges, observables for the reactions $γp\to K^{*0}Σ^+$ and $γp\to K^{*+}Σ^0$ are predicted, using the SU(3)-flavor-blind assumption of non-perturbative QCD.

Rennan Barkana, Zoltan Haiman, Jeremiah P. Ostriker

We study the constraints that high-redshift structure formation in the universe places on warm dark matter (WDM) dominated cosmological models. We modify the extended Press-Schechter formalism to derive the halo mass function in WDM models. We show that our predictions agree with recent numerical simulations at low redshift over the halo masses of interest.

Xingxiang Zhou, Jonathan L. Habif, Mark F. Bocko, Marc J. Feldman

We introduce a technique to control the macroscopic quantum state of an rf SQUID qubit. We propose to employ a stream of single flux quantum (SFQ) pulses magnetically coupled to the qubit junction to momentarily suppresses its critical current. This effectively lowers the barrier in the double-well rf-SQUID potential thereby increasing the tunneling oscillat

Roberto C. Rey-de-Castro, Mark F. Bocko, Andrea M. Herr, Cesar A. Mancini

We believe that the best chance to observe macroscopic quantum coherence (MQC) in a rf-SQUID qubit is to use on-chip RSFQ digital circuits for preparing, evolving and reading out the qubit's quantum state. This approach allows experiments to be conducted on a very short time scale (sub-nanosecond) without the use of large bandwidth control lines that wou

Ding-Yu Chung

In this paper, the base of quantum mechanics is the spontaneous tendency for a microscopic object to fractionalize instantly into quasistates and condense instantly quasistates. This quasistate is equivalent to the eigenfunction. An object with the fractionalization-condensation is equivalent to the unitary wavefunction. Nonlocal operation is explicitly requ

A. S. Botvina

Two instructive effects concerning fragment production at disintegration of finite nuclei are predicted with the statistical multifragmentation model: (1) a concentration of neutrons in intermediate mass fragments during the phase transition, (2) the break of the spatial symmetry of the fragment's isospin distribution, as well as of the symmetry of the f

A. V. Kitaev

We discuss relations which exist between analytic functions belonging to the recently introduced class of special functions of the isomonodromy type (SFITs). These relations can be obtained by application of some simple transformations to auxiliary ODEs with respect to a spectral parameter which associated with each SFIT. We consider two applications of rati

A. V. Kitaev

We consider deformations of $2\times2$ and $3\times3$ matrix linear ODEs with rational coefficients with respect to singular points of Fuchsian type which don't satisfy the well-known system of Schlesinger equations (or its natural generalization). Some general statements concerning reducibility of such deformations for $2\times2$ ODEs are proved. An exp

Alice Fialowski, Michael Penkava

This article explores some simple examples of L-infinity algebras and the construction of miniversal deformations of these structures. Among other things, it is shown that there are two families of nonequivalent L-infinity structures on a 1|1 dimensional vector space, two of which are Lie algebra structures. The main purpose of this work is to provide a simp

Sostenes Lins, Michele Mulazzani

We solve the isomorphism problem for the whole class of Lins-Mandel gems (graphs encoded manifolds). We also present certain homeomorphisms of branched cyclic coverings of two-bridge hyperbolic links. As a consequence, we prove that, in in a wide subset of interesting cases, the isomorphism conditions for Lins-Mandel gems are equivalent to the homeomorphism

M. R. Razvan

An SIRS epidemiological model for a vertically transmitted disease is discussed. We give a complete global analysis in terms of three explicit threshold parameters which respectively govern the existence and stability of an endemic proportion equilibrium, the increase of the total population and the growth of the infective population. This paper gereralize t

Lynne H. Orr, W. J. Stirling

In certain regions of phase space in jet production, large logarithms can arise which are resummed by the BFKL equation. Linear colliders can potentially be excellent places to study BFKL effects in jet production. We discuss an approach to BFKL calculations which incorporates kinematic effects explicitly and can be implemented in an event generator.

Lynne H. Orr

This talk summarizes recent progress in top quark physics studies for high energy linear electron-positron colliders as presented at the LCWS2000 Workshop at Fermilab. New results were presented for top pair production at threshold and in the continuum, as well as for top production at $γγ$ colliders.

J. Bartels, M. A. Braun, D. Colferai, G. P. Vacca

Using a set of new odderon states, we calculate their contribution to the diffractive eta_c photo- and electroproduction process. Compared to previous simple 3-gluon exchange calculations we find an enhancement of about one order of magnitude in the cross section. The t-dependence of the cross section exhibits a dip structure in the small t region.

A. Ogawa, V. L. Rykov, N. Saito

The capabilities of RHIC with polarized protons to test the Lorentz structure of electroweak interactions and also the properties of MSSM Higgs, should it be discovered, are discussed.

Poghos F. Kazarian

The homogeneous cosmological model in GR is proposed, where the vacuum energy, which can cause the inflation, is described by tensor field rather than by commonly used in inflationary scenarios scalar field. It is shown that if the initial values of the field are sufficiently big (comparable with the Planck units), under the condition of the tensor field&#39

Ninan Sajeeth Philip, K. Babu Joseph

Rainfall in Kerala State, the southern part of Indian Peninsula in particular is caused by the two monsoons and the two cyclones every year. In general, climate and rainfall are highly nonlinear phenomena in nature giving rise to what is known as the `butterfly effect'. We however attempt to train an ABF neural network on the time series rainfall data an

Sebastian Risau-Gusman, Mirta B. Gordon

We study the typical learning properties of the recently introduced Soft Margin Classifiers (SMCs), learning realizable and unrealizable tasks, with the tools of Statistical Mechanics. We derive analytically the behaviour of the learning curves in the regime of very large training sets. We obtain exponential and power laws for the decay of the generalization

E. T. Seppälä, M. J. Alava, P. M. Duxbury

We study at T=0 the minimum energy of a domain wall and its gap to the first excited state concentrating on two-dimensional random-bond Ising magnets. The average gap scales as $ΔE_1 \sim L^θf(N_z)$, where $f(y) \sim [\ln y]^{-1/2}$, $θ$ is the energy fluctuation exponent, $L$ length scale, and $N_z$ the number of energy valleys. The logarithmic scaling is d

Barbara Drossel, M. A. Moore

We study the low-temperature phase of the three-dimensional $\pm J$ Ising spin glass in Migdal-Kadanoff approximation. At zero temperature, T=0, the properties of the spin glass result from the ground-state degeneracy and can be elucidated using scaling arguments based on entropy. The approach to the asymptotic scaling regime is very slow, and the correct ex

Marek Cieplak, Trinh Xuan Hoang

Scaling of folding times in Go models of proteins and of decoy structures with the Lennard-Jones potentials in the native contacts reveal %robust power law trends when studied under optimal folding conditions. The power law exponent depends on the type of native geometry. Its value indicates lack of kinetic optimality in the model proteins. In proteins, mech

J. Swift, W. J. Welch, B. Frye

This paper presents data from the BIMA interferometer showing spatially resolved absorption spectra of the gravitationally lensed quasar PKS 1830-211. High-resolution (1.2 km/s) spectra were taken in two spectral windows centered on the redshifted frequencies of the HCO+(2-1) and HCN(2-1) molecular transitions. There is no molecular absorption in the northea

Ch. Lange, F. Camilo, N. Wex, M. Kramer

We present results and applications of high precision timing measurements of the millisecond pulsar J1012+5307. Combining our radio observations with results based on optical observations, we derive complete 3-D velocity information for this system. Correcting for Doppler effects, we derive the intrinsic spin parameters of this pulsar and a characteristic ag

S. Mathur, G. Matt, P. J. Green, M. Elvis

We present a deep ($\sim$85 ksec) ASCA observation of the prototype Broad Absorption Line Quasar (BALQSO) PHL 5200. This is the best X-ray spectrum of a BALQSO yet. We find that (1) the source is not intrinsically X-ray weak, (2) the line of sight absorption is very strong with N_H=5 x 10^{23} cm^{-2}, (3) the absorber does not cover the source completely; t

Sunetra Giridhar, David L. Lambert, Guillermo Gonzalez, Gajendra Pandey

We present the chemical compositions of four K giants CS 22877-1, CS 22166-16, CS22169-35 and BS 16085 - 0050 that have [Fe/H] in the range -2.4 to -3.1. Metal-poor stars with [Fe/H] < -2.5 are known to exhibit considerable star - to - star variations of many elements. This quartet confirms this conclusion. CS 22877-1 and CS 22166-16 are carbon-rich. There i

L. L. Cowie, A. J. Barger, M. W. Bautz, P. Capak

We combine deep Subaru near-infrared images of the massive lensing clusters A2390 and A370 with Keck optical data to map the spectral energy distributions (SEDs) of Chandra X-ray sources lying behind the clusters. The three sources behind A2390 are found to have extremely red colors with SEDs consistent with evolved galaxies at redshifts z>1.4. One source ha

Malcolm P. Kennett, Mona Berciu, R. N. Bhatt

We examine the feasibility of a simple description of Mn ions in III-V diluted magnetic semiconductors (DMSs) in terms of two species (components), motivated by the expectation that the Mn-hole exchange couplings are widely distributed, expecially for low Mn concentrations. We find, using distributions indicated by recent numerical mean field studies, that t

Tarek Ibrahim

The mixing among the CP even and the CP odd neutral Higgs bosons of MSSM by one loop induced effects in the presence of CP phases is investigated using three different mechanisms to satisfy the EDM constraints, i.e., a fine tuning of phases, a heavy sparticle spectrum, and the cancellation mechanism. It is shown that if a mixing effect among the CP even and

Victor Chernyak

Estimates are presented for the branching ratios of several two-particle B-meson decays into flavoured scalar mesons.

V. V. Flambaum, F. M. Izrailev

We study the time evolution of an initially excited many-body state in a finite system of interacting Fermi-particles in the situation when the interaction gives rise to the ``chaotic&#39;&#39; structure of compound states. This situation is generic for highly excited many-particle states in quantum systems, such as heavy nuclei, complex atoms, quantum dots,

Moncy V John

A modified de Broglie-Bohm (dBB) approach to quantum mechanics is presented. In this new deterministic theory, the problem of zero velocity for bound states does not appear. Also this approach is equivalent to standard quantum mechanics when averages of dynamical variables are taken, in exactly the same way as in the original dBB theory.

Yoel Lana-Renault

An explicit, oscillatory solution of the type r = [A + B sin(wt)]exp(a) is found for the zero-energy one-dimensional motion of a particle under a specific family of anharmonic potentials. We present a new parametric family of anharmonic potentials for which one is able to obtain closed analytical solutions for the trajectories of zero-energy.

K. Hagino, H. Sagawa

We formulate a quasi-particle random phase approximation (QRPA) in the coordinate space representation. This model is a natural extension of the RPA model of Shlomo and Bertsch to open-shell nuclei in order to take into account pairing correlations together with the coupling to the continuum. We apply it to the $^{120}$Sn nucleus and show that low-lying exci

S. P. Avdeyev, V. A. Karnaukhov, L. A. Petrov, V. K. Rodionov

Multiple emission of intermediate-mass fragments has been studied for the collisions of p, $^4$He and $^{12}$C on Au with the $4π$ setup FASA. In the case of $^{12}$C(22.4 GeV)+Au and $^4$He(14.6 GeV)+Au collisions, the deviations from a pure thermal break-up are seen in the energy spectra of the emitted fragments: the spectra are harder than calculated and

M. L. Allaberdin, M. A. Belov, K. G. Gulamov, V. D. Lipin

New experimental data of the comparative analysis of channels of the production of three α-particles and ^12C nuclei in ^16Op-collisions at 3.25 A GeV/c are submitted. It is shown, that the channel with the three α-particles production is realised in a half part of events as a result of decay of an excited ^12C^* nucleus, and the rest part of the channel - b

T. Grava

We study the Cauchy problem for the Korteweg de Vries (KdV) equation with small dispersion and with monotonically increasing initial data using the Riemann-Hilbert (RH) approach. The solution of the Cauchy problem, in the zero dispersion limit, is obtained using the steepest descent method for oscillatory Riemann-Hilbert problems. The asymptotic solution is

David Bessis, Cedric Bonnafe, Raphael Rouquier

We give a geometric description of a certain class of epimorphisms between complex reflection groups. We classify these epimorphisms, which can be interpreted as ``morphisms&#39;&#39; between the diagrams symbolizing standard presentations by generators and relations for complex reflection groups and their braid groups.

Marek Jarnicki, Peter Pflug

Let $D, G\subset{\Bbb C}$ be domains, let $A\subset D$, $B\subset G$ be locally regular sets, and let $X:=(D\times B)\cup(A\times G)$. Assume that $A$ is a Borel set. Let $M$ be a proper analytic subset of an open neighborhood of $X$. Then there exists a pure 1-dimensional analytic subset $\hat M$ of the envelope of holomorphy $\hat X$ of $X$ such that any f

Thomas Becher, Matthias Neubert, Ben D. Pecjak

Using the renormalon calculus, we study the asymptotic behavior of the perturbative expansion of the hard-scattering kernels entering the QCD factorization formula for the nonleptonic weak decays B->D M, where M is a light meson. In the ``large-beta_0 limit&#39;&#39;, the kernels are infrared finite and free of endpoint singularities to all orders of perturb

K. Terasaki

The D^+ --> omega + pi^+ decay is studied by decomposing its amplitude into a sum of factorizable and non-factorizable ones. Its rate is predicted as a function of mass and width of a hypothetical hybrid meson.

Sung-Won Kim

In this paper, we study the scattering problem of the scalar wave in the traversable Lorentzian wormhole geometry. The potentials and Schrödinger-like equations are found in cases of the static uncharged and the charged wormholes. The differential scattering cross sections are determined by the phase shift of the asymptotic wave function in low frequency lim

Sung-Won Kim, Hyunjoo Lee

In this paper, the backreaction to the traversable Lorentzian wormhole spacetime by the scalar field or electric charge is considered to find the exact solutions. The charges play the role of the additional matter to the static wormhole which is already constructed by the exotic matter. The stability conditions for the wormhole with scalar field and electric

E. A. Jagla

In a recent letter (Phys. Rev. Lett. 84, 4629 (2000)), Lacks presents evidence of a first order amorphous-amorphous transition in silica at T=0. He calculates the free energy along a path of compression and successive decompression of a sample of 108 SiO2 units. The free energy of the two branches cross each other, and this is interpreted as evidence of a fi

Lawrence M. Krauss

Over the past three years, our confidence in the inferred values of cosmological parameters has increased dramatically, confirming that the flat matter dominated Universe that dominated cosmological model building for the past 20 years does not correspond to the Universe in which we live. I review recent developments here and quote best fit current values fo

Gia Dvali, Gregory Gabadadze, Marko Kolanovic, Francesco Nitti

We study the role of the brane-induced graviton kinetic term in theories with large extra dimensions. In five dimensions we construct a model with a TeV-scale fundamental Planck mass and a {\it flat} extra dimension the size of which can be astronomically large. 4D gravity on the brane is mediated by a massless zero-mode, whereas the couplings of the heavy K

Mu-Chun Chen, K. T. Mahanthappa

We obtain a {\it complete set} of one-loop RGE&#39;s for a set of combinations of neutrino parameters for the case of two-fold degenerate hierarchical three-neutrino models. The requirement of consistency of exact solutions to these RGE&#39;s with the two-fold degeneracy yields conditions which have previously been obtained perturbatively/numerically. These

Andrew Gould

Grid stars and reference stars provide the fundamental global and local astrometric reference frames for observations by the Space Interferometry Mission. They must therefore be astrometrically stable at the ~1 uas level. I present simple formulae in closed form to estimate contamination of these frames by motions due to stellar companions that go undetected

Daniel Arndt

The shape of the neutrino pulse from the supernova SN1987a provides one of the most stringent constraints on the size of large, compact, &#34;gravity-only&#34; extra dimensions. Previously, calculations have been carried out for a newly-born proto-neutron star with a temperature of about 50 MeV at nuclear matter density. It is arguable that, due to the extre

Reginald J. Hill

Traditionally, trends of universal turbulence statistics are presented versus R-lambda, which is the Reynolds number based on Taylor&#39;s scale, lambda, and the root-mean-squared (rms) velocity component, u&#39;. Taylor&#39;s scale and u&#39;, and hence R-lambda, do not have the attribute of universality. The ratio of rms fluid-particle acceleration to rms

A. G. Yashenkin, W. A. Atkinson, I. V. Gornyi, P. J. Hirschfeld

The low-energy density of states (DOS) of disordered 2D d-wave superconductors is extremely sensitive to details of both the disorder model and the electronic band structure. Using diagrammatic methods and numerical solutions of the Bogoliubov-de Gennes equations, we show that the physical origin of this sensitivity is the existence of a novel diffusive mode

A. Buchel, C. P. Herzog, I. R. Klebanov, L. Pando Zayas

The world volume theory on $N$ regular and $M$ fractional D3-branes at the conifold singularity is a non-conformal ${\cal N}=1$ supersymmetric $SU(N+M)\times SU(N)$ gauge theory. In previous work the extremal Type IIB supergravity dual of this theory at zero temperature was constructed. Regularity of the solution requires a deformation of the conifold: this

Reginald J. Hill

Exact equations are derived that relate velocity structure functions of arbitrary order with other statistics. &#34;Exact&#34; means that no approximations are used except that the Navier-Stokes equation and incompressibility condition are assumed to be accurate. The exact equations are used to determine the structure-function equations of all orders for loc

P. E. Kornilovitch, A. M. Bratkovsky

We study the current through molecular films as a function of orientation of the molecules in the film with respect to electrodes. It may change by more than an order of magnitude, depending on the angle between the axis of the molecules and the normal to the electrode. This is a consequence of a strong directional character of $p$-orbitals that determines t

Uma Mahanta

In this paper we study the implications of the recent high precision measurement of (g-2)_μ by BNL on new heavy physics beyond the SM in a model independent way. We find that if the new physics responsible for the muon anomaly is due to d=6 direct operators then they could arise from the following follwing three broad classes of new physics a) new particles

H. O. Girotti, M. Gomes, V. O. Rivelles, A. J. da Silva

We show that the noncommutativity of space-time destroys the renormalizability of the 1/N expansion of the O(N) Gross-Neveu model. A similar statement holds for the noncommutative nonlinear sigma model. However, we show that, up to the subleading order in 1/N expansion, the noncommutative supersymmetric O(N) nonlinear sigma model becomes renormalizable in D=

I. V. Anikin, O. V. Teryaev

We present the alternative way of derivation of the Wandzura-Wilczek relations between the kinematical twist-3 and twist-2 functions, parameterizing hadronic matrix element in two-photon processes $γ^{\star}π\to γπ$ and $γ^{\star}γ\toππ$. The new equations, providing the independence of the physical cross-sections on the choice of the light-cone direction, a

Jerzy Kowalski-Glikman

It has been observed recently by Giovanni Amelino-Camelia \cite{gac1, gac2} that the hypothesis of existence of a minimal observer-independent (Planck) length scale is hard to reconcile with special relativity. As a remedy he postulated to modify special relativity by introducing an observer-independent length scale. In this letter we set forward a proposal

Lukas Phaf, Stefan Weinzierl

We extend the dipole formalism of Catani and Seymour to QCD processes involving heavy fermions. We give the appropriate subtraction terms together with their integrated counterpart. All calculations are done within dimensional regularization. Our formulae can be used with three variants of dimensional regularization (conventional dimensional regularization,

T. D. Cohen, L. Ya. Glozman

It has recently been suggested that the parity doublet structure seen in the spectrum of highly excited baryons may be due to effective chiral restoration for these states. We argue how the idea of chiral symmetry restoration high in the spectrum is consistent with the concept of quark-hadron duality. If chiral symmetry is effectively restored for highly-lyi

Yas-Hiro Quano

The $A^{(1)}_{n-1}$-face model with boundary reflection is considered on the basis of the boundary CTM bootstrap. We construct the fused boundary Boltzmann weights to determine the normalization factor. We derive difference equations of the quantum Knizhnik-Zamolodchikov type for correlation functions of the boundary model. The simplest difference equations

Hiroaki Terashima

We rederive the Brown-Henneaux commutation relation and central charge in the framework of the path integral. To obtain the Ward-Takahashi identity, we can use either the asymptotic symmetry or its leading part. If we use the asymptotic symmetry, the central charge arises from the transformation law of the charge itself. Thus, this central charge is clearly