April 2000 arXiv papers — page 2

Seif Randjbar-Daemi

A brief review of aspects of gravity gauge theory correspondance inspired by string theory is presented.

S. James Gates, B. Radak, V. G. J. Rodgers

We review the enveloping algebra of the 10 dimensional chiral sigma matrices. To facilitate the computation of the product of several chiral sigma matrices we have developed a symbolic program. Using this program one can reduce the multiplication of the sigma matrices down to linear combinations of irreducilbe elements. We are able to quickly derive several

S. Sultansoy

The flavor democracy favors the existence of the nearly degenerate fourth SM family, whereas the fifth SM family is disfavored both by the mass phenomenology and precision tests of the Standard Model. The multi-hundreds GeV fourth family quarks will be copiously produced at the LHC. However, the first indication of the fourth family may come from the Higgs s

R. Kuhn, F. Krauss, B. Ivanyi, G. Soff

APACIC++ is a Monte-Carlo event-generator dedicated for the simulation of electron-positron annihilations into jets. Within the framework of APACIC++, the emergence of jets is identified with the perturbative production of partons as governed by corresponding matrix elements. In addition to the build-in matrix elements describing the production of two and th

M. Giovannini, M. Shaposhnikov

The hot plasma above the electroweak scale contains (hyper) charged scalar particles which are coupled to Abelian gauge fields. Scalars may interact with gravity in a non-conformally invariant way and thus their fluctuations can be amplified during inflation. These fluctuations lead to creation of electric currents and produce inhomogeneous distribution of c

V. Barone, C. Pascaud, F. Zomer

We present the results of a new global analysis of DIS data characterized by an enlarged neutrino and antineutrino data set. Special emphasis is given to the strange sector. The strange sea distribution is determined independently of the non strange sea. The possibility of a charge asymmetry, s(x) different from sbar(x), is tested.

T. Barakat

The radiative leptonic $B_{c}\toτ\bar{ν_τ}γ$ decay is analysed in context of 2HDM. It is shown that with large values of $tanβ$, the contributions of Model II to the decay rate exceeds considerably the Standard Model ones, while the contributions of Model I overlap with the Standard Model predictions.

B. Guberina, B. Melic, H. Stefancic

The preasymptotic effects originating from the four-quark operators are disentangled from the other contributions by considering appropriate combinations of inclusive decay rates. Under the assumption of the isospin and heavy-quark symmetry, a set of relations connecting charmed and beauty decays is obtained without invoking specific models. The results are

Ailin Zhang

The spectra of some 0++ four-quark states, which are composed of \bar qq pairs, are calculated in QCD. The light four-quark states are calculated using the traditional sum rules while four-quark states containing one heavy quark are computed in HQET. For constructing the interpolating currents, different couplings of the color and spin inside the \bar qq pai

V. K. Mitrjushkin

It is shown that the free propagator of an angular, i.e. compact, field with zero lagrangian mass acquires a nonzero propagator mass $ω$ (`kinematical' mass generation). To demonstrate this effect the free propagator of the goldstone boson in an O(2) model with spontaneous symmetry breaking is calculated. It is shown that this propagator is massive, the

Derek B. Leinweber

Action and topological charge densities of the Euclidean-space QCD vacuum are visualized in three-dimensional slices of a 24^3 x 36 space-time lattice and an order-a^2 improved 16^3 x 32 lattice. Features include instanton anti-instanton annihilation and a comparison of standard and over-improved actions used in the smoothing of the gauge fields.

J. Andrew Green

Quark-quark and quark-lepton searches for compositenss at the Fermilab Tevatron are summarized. These are of the contact-interaction variety where sqrt(s-hat) < the hypothesized mass scales, Lambda. Tevatron experiments limit a variety of compositeness phenomena in the range from 1.9 to 8.3 TeV. These limits result from measurements of: the Ht spectrum (D0),

R. Ammar

Based on an a high statistics e+e- -> ccbar data sample, we report on the inclusive rate for charmed baryons to decay into / particles using charm-event tagging. We select e+e- -> ccbar events which have a clear anti-charm tag and measure the / content in the hemisphere opposite the tag (charge conjugate modes are implicit). This allows us to determine the p

J. C. N. de Araujo, A. Wang

A solution to the Einstein field equations that represents a rigidly rotating dust accompanied by a thin matter shell of the same type is found.

Yuri N. Obukhov, Eugen J. Vlachynsky

The Proca wave equation describes a classical massive spin 1 particle. We analyze the gravitational interaction of this vector field. In particular, the spherically symmetric solutions of the Einstein-Proca coupled system are obtained numerically. Although at infinity the metric field approaches the usual Schwarzschild (Reissner-Nordström) limit, we demonstr

Israel Quiros, Rolando Cardenas, Rolando Bonal

In the present paper we give conclusive arguments pointing at physical equivalence among conformally related metrics. Based on the argument that any consistent effective theory of spacetime must be invariant under the one-parameter group of transformations of the units of length, time and reciprocal mass, it is shown, also, that canonical general relativity

Harry Buhrman, Ronald de Wolf

The quantum version of communication complexity allows the two communicating parties to exchange qubits and/or to make use of prior entanglement (shared EPR-pairs). Some lower bound techniques are available for qubit communication complexity, but except for the inner product function, no bounds are known for the model with unlimited prior entanglement. We sh

Tony Berber Sardinha

This paper is aimed at reporting on the development and application of a computer model for discourse analysis through segmentation. Segmentation refers to the principled division of texts into contiguous constituents. Other studies have looked at the application of a number of models to the analysis of discourse by computer. The segmentation procedure devel

J. E. Hirsch, F. Marsiglio

The model of hole superconductivity predicts that the superfluid weight in the zero-frequency $δ$-function in the optical conductivity has an anomalous contribution from high frequencies, due to lowering of the system&#39;s kinetic energy upon entering the superconducting state. The lowering of kinetic energy, mainly in-plane in origin, accounts for both the

G. Franzese, V. Cataudella, S. E. Korshunov, R. Fazio

We introduce a fully frustrated XY model with nearest neighbor (nn) and next nearest neighbor (nnn) couplings which can be realized in Josephson junction arrays. We study the phase diagram for $0\leq x \leq 1$ ($x$ is the ratio between nnn and nn couplings). When $x < 1/\sqrt{2}$ an Ising and a Berezinskii-Kosterlitz-Thouless transitions are present. Both cr

H. Kaps, N. Büttgen, W. Trinkl, A. Loidl

7Li NMR measurements were performed in the metallic spinel LiV2O4. The temperature dependencies of the line width, the Knight shift and the spin-lattice relaxation rate were investigated in the temperature range 30 mK < T < 280 K. For temperatures T < 1 K we observe a spin-lattice relaxation rate which slows down exponentially. The NMR results can be explain

Guillermo A. Cecchi, Mariano Sigman, Jose-Manuel Alonso, Luis Martinez

Neuronal responses are conspicuously variable. We focus on one particular aspect of that variability: the precision of action potential timing. We show that for common models of noisy spike generation, elementary considerations imply that such variability is a function of the input, and can be made arbitrarily large or small by a suitable choice of inputs. O

A. Comtet, S. Nechaev, R. Voituriez

We introduce a deterministic model defined on a two dimensional hyperbolic lattice. This model provides an example of a non random system whose multifractal behaviour has a number theoretic origin. We determine the multifractal exponents, discuss the termination of multifractality and conjecture the geometric origin of the multifractal behavior in Liouville

J. M. de Araujo, F. A. da Costa, F. D. Nobre

The effects of competing quadrupolar- and spin-glass orderings are investigated on a spin-1 Ising model with infinite-range random $p$-spin interactions. The model is studied through the replica approach and a phase diagram is obtained in the limit $p\to\infty$. The phase diagram, obtained within replica-symmetry breaking, exhibits a very unusual feature in

H. A. Pinnow, W. Helfrich

We amplify previous arguments why mean curvature should be used as measure of integration in calculating the effective bending rigidity of fluid membranes subjected to a weak background curvature. The stiffening of the membrane by its fluctuations, recently derived for spherical shapes, is recovered for cylindrical curvature. Employing curvilinear coordinate

Satya N. Majumdar, David S. Dean, Peter Grassberger

We study the zero temperature coarsening dynamics in an Ising chain in presence of a dynamically induced field that favors locally the `-&#39; phase compared to the `+&#39; phase. At late times, while the `+&#39; domains still coarsen as $t^{1/2}$, the `-&#39; domains coarsen slightly faster as $t^{1/2}\log (t)$. As a result, at late times, the magnetization

Ulrich Bilstein

We calculate the magnetization profiles of the $σ_j^x$ and $σ_j^z$ operators for the XX-model with hermitian boundary terms. We study the profiles on the finite chain and in the continuum limit. The results are discussed in the context of conformal invariance. We also discuss boundary excitations and their effect on the magnetization profiles.

M. Einax, S. Trimper, H. -R. Hoeche, M. Schulz

We investigate numerically a simple microscopic model to describe wearless dry friction between atomically flat contact interfaces without thermal fluctuations (T=0K). The analysis of the incommensurate ground state shows a breaking of analyticity when the amplitude $ε$ of the Lennard-Jones interaction between the both harmonic chains increased beyond a crit

S. del Campo, N. Cruz

In a Brans-Dicke (BD) cosmological model, the energy density associated with some scalar field decreases as $\displaystyle a^{{-2}(\frac{ω_{o}+ {\frac12}%}{ω_{o}+1})} $ with the scale factor $a(t)$ of the Universe, giving a matter with an Equation of state $\displaystyle p=-{1/3}(\frac{2+ω_{o}}{1+ω_{o}}) ρ$. In this model, the Universe could be closed but st

Christopher W. Mauche, John C. Raymond

The Extreme Ultraviolet Explorer (EUVE) satellite was used for three days beginning on 1997 Mar 26.96 UT to obtain photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova OY Carinae in superoutburst. Because of the longer time on source (143 ks), the larger number of eclipses observed (17), and the higher count rate in the detector

Paul R. Shapiro, Alejandro C. Raga

The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and photoevaporating them. This feedback of universal reionization on cosmic structure formation is demonstrated here by gas dynamical simulations, including radiative trans

Timothy M. Braje, Roger W. Romani, Kevin P. Rauch

We consider the effect of rapid rotation on the light curves of neutron stars with hot polar caps. For $P \approx 3$ms spin periods, the pulse fractions can be as much as an order of magnitude larger than with simple slowly-rotating (Schwarzschild) estimates. Doppler boosting, in particular, leads to characteristic distortion and ``soft lags&#39;&#39; in the

E. B. Jenkins, W. R. Oegerle, C. Gry, J. Vallerga

FUSE spectra of the white dwarf stars G191-B2B, GD 394, WD 2211-495 and WD 2331-475 cover the absorption features out of the ground electronic states of N I, N II, N III, O I and Ar I in the far ultraviolet, providing new insights on the origin of the partial ionization of the Local Interstellar Medium (LISM), and for the case of G191-B2B, the interstellar c

S. K. Leggett, T. R. Geballe, Xiaohui Fan

We report the discovery of three cool brown dwarfs which fall in the effective temperature gap between the latest L dwarfs currently known, with no methane absorption bands in the 1-2.5um range, and the previously known methane (T) dwarfs, whose spectra are dominated by methane and water. The newly discovered objects were detected as very red objects in the

Timothy M. Braje, Roger W. Romani

We model the formation of magnetospheric components of millisecond pulsar light curves, deriving an approximate model for the curved space, `swept-back&#39; dipole field and following photon emission, propagation, and scattering. Magnetospheric pulse components are strongly affected by rapid rotation and Schwarzschild effects.

M. T. Meliani, J. C. N. de Araujo, O. D. Aguiar

General Relativity predicts that binary systems of stars produce gravitational waves of significant intensity. Here we are particularly interested in the cataclysmic variable binaries (CVs). These systems emit low frequency gravitational waves, $ f < 10^{-3} Hz$. We present here a catalog of CVs and argue that part of them are capable of being detected by th

Peter M. Weilbacher, P. -A. Duc, U. Fritze-v. Alvensleben, P. Martin

We present deep optical B, V, R images of a sample of 10 interacting systems which were selected for their resemblance to disturbed galaxies at high redshift. Photometry is performed on knots in the tidal features of the galaxies. We calculate a grid of evolutionary synthesis models with two metallicities and various burst strengths for systems consisting of

P. de Bernardis, P. A. R. Ade, J. J. Bock, J. R. Bond

The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73K Cosmic Microwave Background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basi

R. L. Aptekar, D. D. Frederiks, S. V. Golenetskii, V. N. Il&#39;inskii

Observational data on the bursting activity of all five known Soft Gamma Repeaters are presented. This information was obtained with Konus gamma-ray burst experiments on board Venera 11-14, Wind, and Kosmos-2326 spacecraft in the period from 1978 to 2000. These data on appearance rates, time histories, and energy spectra of repeated soft bursts obtained with

Luis C. Ho, Greg Rudnick, Hans-Walter Rix, Joseph C. Shields

Spectra taken with HST reveal that NGC 4450 emits Balmer emission lines with displaced double peaks and extremely high-velocity wings. This characteristic line profile, previously seen in a few nearby LINERs and in a small fraction of broad-line radio galaxies, can be interpreted as a kinematic signature of a relativistic accretion disk. We can reproduce the

Evalyn Gates, Geza Gyuk

We suggest a new component of the Milky Way that can account for both the optical depth and event durations implied by microlensing searches targeting the Large Magellanic Cloud. This component, which represents less than 4% of the total dark matter halo mass, consists of mainly old white dwarf stars in a distribution that extends beyond the disk of the gala

J. Poirier, J. Gress, T. F. Lin

Project GRAND preents a map in right ascension and declination for single cosmic secondary tracks which have been identified as muons. These muons are measured in stations of proportional wire chambers (PWCs) which have a mean angular resolution of 0.26 deg. A 50 mm steel plate interspersed with the PWCs is used to distinguish muons from electrons. Two years

Paolo Salucci, Andreas Burkert

We establish the presence of a dark matter core radius, for the first time in a very large number of spiral galaxies of all luminosities. Contrary to common opinion we find that the sizes of these cores and the &#34; DM core problem&#34; are bigger for more massive spirals. As a result the Burkert profile provides an excellent mass model for dark halos aroun

T. F. Lin, B. Fields, J. Gress, J. Poirier

Project GRAND measures the asymmetries of secondary cosmic muons by calculating the differences between the muons from the east and the muons from the west for complete solar days. A similar north-south difference is also presented. These muons are identified in single track data taken with the 64 stations of Project GRAND; the data cover a two year span wit

J. C. N. de Araujo, O. D. Miranda, O. D. Aguiar

A continuous stochastic background of gravitational waves (GWs) for burst sources is produced if the mean time interval between the occurrence of bursts is smaller than the average time duration of a single burst at the emission, i.e., the so called duty cycle must be greater than one. To evaluate the background of GWs produced by an ensemble of sources, dur

J. Poirier, J. Carpenter, S. Desch, J. Gress

Project GRAND is an extensive air shower array utilizing position sensitive detectors of proportional wire chambers. The 64 detectors deployed in a field 100 m x 100 m are located at 86.2 deg W and 41.7 deg N, at 220 m above sea level. The project was completed about two years ago and has been taking data, simultaneously on two triggers: 1) multiple-hit coin

Takahiko Matsubara

The gravitational lensing, as well as the velocity field and the cosmological light-cone warp, changes the observed correlation function of high-redshift objects. We present an analytical expression of 3D correlation function, simultaneously including those three effects. When two objects are separated over several hundreds Mpc along a line of sight, the obs

Kenji Bekki, Yasuhiro Shioya

We present a new numerical code which is designed to derive a spectral energy distribution (SED) for an arbitrary spatial distribution of stellar and gaseous components in a dusty starburst galaxy. We apply a ray tracing method to numerical simulations and thereby estimate extinction and reemission of stellar light by dusty gas in an explicitly self-consiste

I. K. Baldry, T. R. Bedding

We present time-series spectroscopy of the rapidly oscillating Ap star HR 3831. This star has a dominant pulsation period of 11.7 minutes and a rotation period of 2.85 days. We have analysed 1400 intermediate-resolution spectra of the wavelength region 6100--7100 AA obtained over one week, using techniques similar to those we applied to another roAp star, Al

P. J. E. Peebles, Sara Seager, Wayne Hu

Under the standard model for recombination of the primeval plasma, and the cold dark matter model for structure formation, recent measurements of the first peak in the angular power spectrum of the cosmic microwave background temperature indicate the spatial geometry of the universe is nearly flat. If sources of Lya resonance radiation, such as stars or acti

J. Ignatius, Dominik J. Schwarz

We investigate a new mechanism for the cosmological QCD phase transition: inhomogeneous nucleation. The primordial temperature fluctuations, measured to be $\delta T/T \sim 10^{-5}$, are larger than the tiny temperature interval, in which bubbles would form in the standard picture of homogeneous nucleation. Thus the bubbles nucleate at cold spots. We find th

Richard Jozsa, Daniel S. Abrams, Jonathan P. Dowling, Colin P. Williams

We demonstrate that two spatially separated parties (Alice and Bob) can utilize shared prior quantum entanglement, and classical communications, to establish a synchronized pair of atomic clocks. In contrast to classical synchronization schemes, the accuracy of our protocol is independent of Alice or Bob&#39;s knowledge of their relative locations or of the

M. Cvetic, H. Lu, C. N. Pope

We prove that any D-dimensional theory comprising gravity, an antisymmetric n-index field strength and a dilaton can be consistently reduced on S^n in a truncation in which just $n$ scalar fields and the metric are retained in (D-n)-dimensions, provided only that the strength of the couping of the dilaton to the field strength is appropriately chosen. A cons

Martin White, Douglas Scott, Elena Pierpaoli

Experimental study of the anisotropy in the cosmic microwave background (CMB) is gathering momentum. The eagerly awaited Boomerang results have lived up to expectations. They provide convincing evidence in favor of the standard paradigm: the Universe is close to flat and with primordial fluctuations which are redolent of inflation. Further scrutiny reveals s

Hui Yin, Bulbul Chakraborty

In an effort to understand the glass transition, the dynamics of a non-randomly frustrated spin model has been analyzed. The phenomenology of the spin model is similar to that of a supercooled liquid undergoing the glass transition. The slow dynamics can be associated with the presence of extended string-like structures which demarcate regions of fast spin f

Frieder Lenz, John W. Negele, Lochlainn O&#39;Raifeartaigh, Michael Thies

After elimination of the redundant variables, gauge theories may still exhibit symmetries associated with the gauge fields. The role of these residual gauge symmetries is discussed within the Abelian Higgs model and the Georgi-Glashow model. In the different phases of these models, these symmetries are realized differently. The characteristics of emergence a

Ali Kaya

In a recent paper, we have pointed out a relation between the Killing spinor and Einstein equations. Using this relation, new brane solutions of D=11 and D=10 type IIB supergravity theories are constructed. It is shown that in a brane solution, the flat world-volume directions, the smeared transverse directions and the sphere located at a fixed radial distan

A. Higuchi, S. S. Kouris

It is known that the graviton two-point function for the de Sitter invariant &#34;Euclidean&#34; vacuum in a physical gauge grows logarithmically with distance in spatially-flat de Sitter spacetime. We show that this logarithmic behaviour is a gauge artifact by explicitly demonstrating that the same behaviour can be reproduced by a pure-gauge two-point funct

Kun Yang, S. L. Sondhi

We study the superconducting instability in systems with long but finite ranged, attractive, pairing interactions. We show that such long-ranged superconductors exhibit a new class of fluctuations in which the internal structure of the Cooper pair wave function is soft, and thus lead to &#34;pseudogap&#34; behavior in which the actual transition temperature

A. Kaminski, M. Randeria, J. C. Campuzano, M. R. Norman

Angle-resolved photoemission (ARPES) data in the superconducting state of Bi2Sr2CaCu2O8+d show a kink in the dispersion along the zone diagonal, which is related via a Kramers-Kronig analysis to a drop in the low-energy scattering rate. As one moves towards (pi,0), this kink evolves into a spectral dip. The occurrence of these anomalies in the dispersion and

Daisuke Nomura

It has been argued in the literature that the search for the slepton oscillation phenomenon can be a powerful probe of intergenerational mixing between sleptons, once sleptons are found at future colliders. In this article we estimate possible reach of future lepton colliders in probing left-handed slepton flavor mixing, especially mixing between the first a

G. A. Kriss, R. F. Green, M. Brotherton, W. Oegerle

We present far-ultraviolet spectra of the Seyfert 1 galaxy Mrk 509 obtained in 1999 November with the Far Ultraviolet Spectroscopic Explorer (FUSE). Our data span the observed wavelength range 915-1185 A at a resolution of ~20 km/s. The spectrum shows a blue continuum, broad OVI 1032,1038 emission, and a broad CIII 977 emission line. Superposed on these emis

Cheng-Wei Chiang, Lincoln Wolfenstein

It has been pointed out by Gronau and Rosner that the angle gamma of the unitarity triangle could be determined by combining future results on B_s and B_d decays to K pi. Here we show that it is important to include in the analysis the information on the phase beta which will be determined in the near future. Omitting this information could lead to an error

J. M. F. Labastida, M. Marino

We make a precision test of a recently proposed conjecture relating Chern-Simons gauge theory to topological string theory on the resolution of the conifold. First, we develop a systematic procedure to extract string amplitudes from vacuum expectation values (vevs) of Wilson loops in Chern-Simons gauge theory, and then we evaluate these vevs in arbitrary irr

P. J. Freitas, R. R. P. Singh

We discuss ways in which the ratio of exchange constants along the rungs and legs of a spin-ladder material influences the two-magnon Raman scattering spectra and hence can be determined from it. We show that within the Fleury-Loudon-Elliott approach, the Raman line-shape does not change with polarization geometries. This lineshape is well known to be diffic

C. M. Hull

A strong coupling limit of theories whose low-energy effective field theory is 5-dimensional N=8 supergravity is proposed in which the gravitational coupling becomes large. It is argued that, if this limit exists, it should be a 6-dimensional theory with (4,0) supersymmetry compactified on a circle whose radius gives the 5-dimensional Planck length. The sect

Shoichi Sasaki

We investigate the mass of the parity partner $N^* (1/2^{-})$ of the nucleon $N(1/2^{+})$, in lattice QCD using a new lattice discretization scheme for fermions, domain wall fermions (DWF). DWF possess exact chiral symmetry and flavor symmetry, both of which are required for this problem, even at finite lattice spacing. Our calculation reproduces the large m

J. Bartelski, S. Tatur

We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we have determined polarised quark and gluon densities. The functional form for such distributions was inspired by the unpolarised ones given by MRST (Martin, Roberts, Stirling and Thorne) fit. In addition to usually used data points (averaged over $Q^2$) we hav

G. Grignani, P. Orland, L. D. Paniak, G. W. Semenoff

We study the null compactification of type-IIA-string perturbation theory at finite temperature. We prove a theorem about Riemann surfaces establishing that the moduli spaces of infinite-momentum-frame superstring worldsheets are identical to those of branched-cover instantons in the matrix-string model conjectured to describe M-theory. This means that the i

Ulf H. Danielsson, Alberto Guijosa, Martin Kruczenski, Bo Sundborg

It has recently been conjectured that the AdS_5/SYM_4 correspondence can be generalized away from the conformal limit, to a duality between supergravity on the full asymptotically flat three-brane background and a theory characterized as N=4 SYM deformed in the IR by a specific dimension-eight operator. Assuming that this relation is valid, we derive a presc

S. Heinz, E. Berdermann, F. Heine, O. Joeres

We present new results from measurements and simulations of positron spectra, originating from 238U + 181Ta collisions at beam energies close to the Coulomb barrier. The measurements were performed using an improved experimental setup at the double-Orange spectrometer of GSI. Particular emphasis is put on the signature of positrons from Internal-Pair-Convers

A. Harindranath, Asmita Mukherjee, Raghunath Ratabole

In this paper we address various issues connected with transverse spin in light front QCD. The transverse spin operators, in $A^+ = 0$ gauge, expressed in terms of the dynamical variables are explicitly interaction dependent unlike the helicity operator which is interaction independent in the topologically trivial sector of light-front QCD. Although it canno

Amol S. Dighe, C. S. Kim

We propose the decay modes $B \to a_0 (\to \eta \pi) \pi$ to determine the CKM phase $\alpha$. One can analyze these modes through (i) the $B \to a_0 \pi$ isospin pentagon, (ii) the time dependent Dalitz plot of $B^0(t) \to a_0^{\pm} \pi^{\mp} \to \eta \pi^+ \pi^-$, and (iii) the time dependence of $B^0(t) \to a_0^0 (\to \eta \pi^0) \pi^0$. We show that the

G. Wilk, Z. Wlodarczyk

To describe high energy collisions one widely uses thermodynamical methods and concepts which follow the classical Boltzmann-Gibbs (BG) approach. In many cases, however, either some deviations from the expected behaviour are observed experimentally or it is known that the conditions necessary for BG to apply are satisfied only approximately. In other branche

Ya Sheng Yang, Chong Sheng Li, Li Gang Jin, Shou Hua Zhu

The $O(α_{ew}m_{t(b)}^{2}/m_{W}^{2})$ and $O(α_{ew} m_{t(b)}^4/m_W^4)$ supersymmetric electroweak corrections to the cross section for $W^{\pm}H^{\mp}$ associated production at the LHC are calculated in the minimal supersymmetric standard model. Those corrections arise from the quantum effects which are induced by the Yukawa couplings from the Higgs sector a

Pedro F. Gonzalez-Diaz

A brane universe derived from the Randall-Sundrum models is considered in which an additional Misner-like periodicity is introduced in the extra direction. This model solves the ambiguity in the choice of the brane world by identifying the branes with opposite tensions, in such a way that if one enters the brane with positive tension, one finds oneself emerg

Stephan Narison

Firstly, we use the recent ALEPH/OPAL data on the V-A spectral functions for fixing the continuum threshold with which the first and second Weinberg sum rules should be satisfied in the chiral limit. Then, we predict the values of the low-energy constants m_{π^+}-m_{π^0}, {L}_{10}, and test the values of the electroweak kaon penguin matrix elements <Q^{3/2}_

A. Le Yaouanc, D. Melikhov, V. Morenas, L. Oliver

Quark-hadron duality in the inclusive semileptonic decay $B\to X_c lν$ in the Shifman-Voloshin limit $Λ\ll δm=m_b - m_c \ll m_b, m_c$ is studied within a nonrelativistic potential model. The integrated semileptonic decay rate is calculated in two ways: first, by constructing the Operator Product Expansion, and second by a direct summation of the exclusive ch

M. Kawasaki, Masahide Yamaguchi, T. Yanagida

We propose a chaotic inflation model in supergravity. In the model the Kähler potential has a Nambu-Goldstone-like shift symmetry of the inflaton chiral multiplet which ensures the flatness of the inflaton potential beyond the Planck scale. We show that the chaotic inflation naturally takes place by introducing a small breaking term of the shift symmetry in

Yi-Ping Qin, Guang-Zhong Xie, Xue-Tang Zheng, En-Wei Liang

We study correlations between various hardness ratios of gamma-ray bursts (GRBs) and investigate if there are any differences between the two classes of the objects in the distributions of the ratios. The results suggest that, statistically, the slope of the higher part of the spectrum of the long duration bursts has nothing to do with that of the lower part

Zhou Fei, Ma Wen-Gan, Jiang Yi, Han Liang

We investigated the production of neutralino pairs via photon-photon collisions in the minimal supersymmetric model(MSSM) at future linear colliders. The numerical analysis of their production rates is carried out in the mSUGRA scenario. The results show that this cross section can reach about 18 femto barn for $\tildeχ^{0}_{1} \tildeχ^{0}_{2}$ pair producti

Keiichi Umetsu, Toshifumi Futamase

We present a weak-lensing analysis of a region around the galaxy cluster Cl 1604+4304 (z=0.897) on the basis of the deep observations with the HST/WFPC2. We apply a variant of Schneider&#39;s aperture mass technique to the observed WFPC2 field and obtain the distribution of weak-lensing signal-to-noise (S/N) ratio within the field. The resulting S/N map reve

Kazuo Fujikawa, Hiroaki Terashima

The use of the mass term as a gauge fixing term has been studied by Zwanziger, Parrinello and Jona-Lasinio, which is related to the non-linear gauge $A_μ^{2}=λ$ of Dirac and Nambu in the large mass limit. We have recently shown that this modified quantization scheme is in fact identical to the conventional {\em local} Faddeev-Popov formula {\em without} taki

Neil Trentham

It is often suggested that the distant galaxies recently identified in 850 micron surveys with the SCUBA bolometer array on the JCMT Telescope are high-redshift analogues to local ultraluminous infrared galaxies, based on their similar spectral energy distributions and luminosities. We show that these two populations of objects must differ in at least one fu

H. C. Rosu

This is a graduate course on elementary quantum mechanics written for the benefit of undergraduate and graduate students. It is the English version of physics/0003106, which I did at the suggestion of several students from different countries. The topics included refer to the postulates of quantum mechanics, one-dimensional barriers and wells, angular moment

H. Aratyn, J. F. Gomes, E. Nissimov, S. Pacheva

We propose a systematic treatment of symmetries of KP integrable systems, including constrained (reduced) KP models ${\sl cKP}_{R,M}$, and their multi-component (matrix) generalizations. Any such integrable hierarchy is shown to possess an additional $({\hat U}(1)\oplus{\hat {SL}}(M))_{+} \oplus ({\hat {SL}}(M+R))_{-}$ loop-algebra symmetry. Also we provide

D. G. Cory, R. Laflamme, E. Knill, L. Viola

Nuclear magnetic resonance (NMR) provides an experimental setting to explore physical implementations of quantum information processing (QIP). Here we introduce the basic background for understanding applications of NMR to QIP and explain their current successes, limitations and potential. NMR spectroscopy is well known for its wealth of diverse coherent man

Pierre Gosselin, Herve Mohrbach

We show that the Renormalization Group formalism allows to compute with accuracy the zero temperature correlation functions and particle densities of quantum systems.

Kazuyuki Fujii

We make a brief review of (optical) Holonomic Quantum Computer (or Computation) proposed by Zanardi and Rasetti (quant-ph/9904011) and Pachos and Chountasis (quant-ph/9912093), and give a mathematical reinforcement to their works.

Noriyoshi Ishii

A systematic evaluation method of matrix elements of quantum one-body operators between nucleon states in the three-quark Bethe-Salpeter(3qBS)/Faddeev approach in the NJL model is reviewed. We do not confine ourselves to a particular truncation scheme of the 3qBS kernel. One of our main aims is to derive a general condition to be imposed on a given BS kernel

A. Holt, T. Engeland, M. Hjorth-Jensen, E. Osnes

We calculate the low-lying spectra of the zirconium isotopes Z=40 with neutron numbers from N=52 to N=60 using the 1p1/20g9/2 proton and 2s1d0g7/20h11/2 neutron sub-shells to define the model space. Effective proton-proton, neutron--neutron and proton-neutron interactions have been derived using 88Sr as closed core and employing perturbative many-body techni

R. P. Martínez-y-Romero, J. Saldaña-Vega, A. L. Salas-Brito

New non-unitary representations of the SU(2) algebra are introduced for the case of the Dirac equation with a Coulomb potential; an extra phase, needed to close the algebra, is also introduced. The new representations does not require integer or half integer labels. The set of operators defined are used to span the complete space of bound state eigenstates o

Tuong Ton-That, Thai-Duong Tran

A methodical analysis of the research related to the article, ``Sur les groupes continus&#39;&#39;, of Henri Poincaré reveals many historical misconceptions and inaccuracies regarding his contribution to Lie theory. A thorough reading of this article confirms the precedence of his discovery of many important concepts, especially that of the \textit{universal

Alexander Astashkevich, Albert Schwarz

We study finitely generated projective modules over noncommutative tori. We prove that for every module $E$ with constant curvature connection the corresponding element $[E]$ of the K-group is a generalized quadratic exponent and, conversely, for every positive generalized quadratic exponent $μ$ in the K-group one can find such a module $E$ with constant cur

Laura Anderson, James F. Davis

We show that there is no triangulation of the infinite real Grassmannian of k-planes in R^\infty which is nicely situated with respect to the coordinate axes. In terms of matroid theory, this says there is no triangulation of the Grassmannian subdividing the matroid stratification. This is proved by an argument in projective geometry, considering a specific

Vyjayanthi Chari, Andrew Pressley

We define a family of universal finite-dimensional highest weight modules for affine Lie algebras, we call these Weyl modules. We conjecture that these are the classical limits of the irreducible finite--dimensional representations of the quantum affine algebras. We prove this conjecture in the case of affine sl_2. We establish a criterion for these modules

Yi Hu

This paper studies two related subjects. One is some combinatorics arising from linear projections of polytopes and fans of cones. The other is quotient varieties of toric varieties. The relation is that projections of polytopes are related to quotients of projective toric varieties and projection of fans are related to quotients of general toric varieties.

S. J. Dilworth, Maria Girardi, J. Hagler

A Banach space contains asymptotically isometric copies of $\ell_1$ if and only if its dual space contains an isometric copy of $L_1$.

Razvan Gelca

The paper shows the computation of the noncommutative generalization of the A-polynomial of the trefoil knot. The classical A-polynomial was introduced by Cooper, Culler, Gillet, Long and Shalen, and was generalized to the context of Kauffman bracket skein modules by the author in joint work with Frohman and Lofaro. A major step in determining the noncommuta

Ivan Cherednik, Yavor Markov

We use a degeneration of the 1D double affine Hecke algebra and the Dunkl operator to study systematically nonsymmetric Bessel functions and their truncations.