September 2002 arXiv papers — page 12

K. Langfeld, J. C. R. Bloch, A. Cucchieri, J. Gattnar

Simulations of SU(2) lattice gauge theory are used to establish a relation between the IR properties of Green functions and confinement. Using Landau gauge where the gauge configurations are restricted to the first Gribov regime, results on the ghost-, gluon form-factor and the running coupling constant are presented. Finally, we discuss the behavior of the

Leticia F Cugliandolo, Gustavo S Lozano, Enrique F Moreno, Fidel A Schaposnik

We discuss the generalization of the connection between the determinant of an operator entering a quadratic form and the associated Gaussian path-integral valid for grassmann variables to the paragrassmann case [$θ^{p+1}=0$ with $p=1$ ($p>1$) for grassmann (paragrassamann) variables]. We show that the q-deformed commutation relations of the paragrassmann var

Bernard L. Julia

It seems to me at this time that two recent developments may permit fast progress on our way to understand the symmetry structure of toroidally (compactified and) reduced M-theory. The first indication of a (possibly) thin spot in the wall that prevents us from deriving a priori the U-duality symmetries of these models is to be found in the analysis of the h

Xavier Bekaert

Chapters : 1. Introduction to electric-magnetic duality 2. Classical duality in bosonic brane electrodynamics 3. Massless spin two gauge theory 4. Duality-symmetric actions and chiral forms 5. BRST quantization of duality-symmetric Maxwell's theory 6. Quantization conditions 7. Consistent deformations

I. Schmelzer

We identify natural degrees of freedom of polycrystalline materials -- affine transformations of grains -- with those of a three-dimensional lattice theory for $(T\otimesΩ)(\mathbb{R}^3)$. We define a lattice Dirac operator on this space and identify its continuous limit with the free field limit of the whole fermionic sector of the standard model. Fermion d

K. Shima, M. Tsuda, M. Sawaguchi

A new Einstein-Hilbert type (SGM) action describing gravitational interaction of Nambu-Goldstone(N-G) fermion of nonlinear supersymmetry(NL SUSY) is obtained by performing the Einstein gravity analogue geometrical arguments in high symmetric four dimensional (SGM) spacetime. All elementary particles except graviton are regarded as the composite eigenstates o

Stefano Arnone, Antonio Gatti, Tim R. Morris

We uncover a method of calculation that proceeds at every step without fixing the gauge or specifying details of the regularisation scheme. Results are obtained by iterated use of integration by parts and gauge invariance identities. The initial stages can even be computed diagrammatically. The method is formulated within the framework of an exact renormaliz

S. Kalyana Rama

We study the commutators of the kappa-deformed Poincare Algebra (kappaPA) in an arbitrary basis. It is known that the two recently studied doubly special relativity theories correspond to different choices of kappaPA bases. We present another such example. We consider the classical limit of kappaPA and calculate particle velocity in an arbitrary basis. It ha

Gordon Chalmers

Gauge theories with and without matter are formulated in the derivative expansion. Amplitudues are derived as a power series in the energy scales; there are simplifications as compared with the usual loop expansion. The incorporation and summation of Wilson loops is natural in this approach and allows for a derivation of the confining potential as well as th

J. Arrington

Recent measurements of recoil polarization in elastic scattering have been used to extract the ratio of the electric to the magnetic proton form factors. These results disagree with Rosenbluth extractions from cross section measurements, indicating either an inconsistency between the two techniques, or a problem with either the polarization transfer or cross

Ph. Hägler, B. Pire, L. Szymanowski, O. V. Teryaev

We review the results of our studies on the charge and the spin asymmetries in the electroproduction of $π^+ π^-$ which are the observables sensitive to the Pomeron-Odderon interference.

A. Donini, D. Meloni, P. Migliozzi

In this talk I show how considering at the same time the $ν_e \to ν_τ$ and the $ν_e \to ν_μ$ oscillation channels the errors in the leptonic CP-violating phase $δ$ measurement could significantly be reduced.

Thorsten Feldmann

Heavy quark decays into energetic, collinear quarks and gluons are discussed within an effective theory that accomplishes the factorization of soft and hard strong interaction effects. We derive the relevant effective Lagrangian, and perform the matching of the heavy quark current, including power corrections of order 1/m, where m is the heavy quark mass. We

Y. Sumino

We review the recent theoretical progress in heavy quarkonium spectroscopy within the boundstate theory based on perturbative QCD. New microscopic pictures of the heavy quarkonium systems are obtained.

Kaushik Bhattacharya, Avijit K. Ganguly

In the presence of a thermal medium or an external electro-magnetic field, neutrinos can interact with photon, mediated by the corresponding charged leptons (real or virtual). The effect of a medium or an electromagnetic field is two-fold - to induce an effective $νγ$ vertex and to modify the dispersion relations of all the particles involved to render the p

Stefan Weinzierl

These lectures given to graduate students in theoretical particle physics, provide an introduction to the ``inner workings'' of computer algebra systems. Computer algebra has become an indispensable tool for precision calculations in particle physics. A good knowledge of the basics of computer algebra systems allows one to exploit these systems more

W. Majerotto

We review the status of radiative corrections to SUSY processes. We present the method of the on-shell renormalization for the sfermion and the chargino/neutralino system and work out the appropriate renormalization conditions. In particular, we discuss slepton, squark, chargino and neutralino production in e+ e- collisions and the two-body decays of sfermio

Xuepeng Sun

The phase transition temperature for the Bose-Einstein condensation (BEC) of weakly-interacting Bose gases in three dimensions is known to be related to certain non-universal properties of the phase transition of three-dimensional O(2) symmetric $ϕ^4$ theory. These properties have been measured previously in Monte Carlo lattice simulations. They have also be

Costas G. Strouthos

With the exception of confinement the three-dimensional Nambu-Jona-Lasinio (NJL_3) model incorporates many of the essential properties of QCD. We discuss the critical properties of the model at nonzero temperature T and/or nonzero chemical potential $μ$. We show that the universality class of the thermal transition is that of the d=2 classical spin model wit

A. Artikov, G. Bellettini, J. Budagov, F. Cervelli

As a part of the CDF Upgrade for Run-II of the Tevatron collider, the azimuthal coverage of the muon detectors between pseudorapidities of 0.6 and 1.2 was completed by the insertion of stacks of drift chambers and scintillation counters, which came to be known as the "miniskirts" because they cover lower 90^o in azimuth. The design and construction o

T. Tabarelli de Fatis

New results from Super-Kamiokande, K2K and SNO not only have spurred on the interest in neutrino oscillation physics, but also have started to shift the interest from discovery to precision measurements. Future projects focusing on atmospheric neutrinos are reviewed in this context. Important contributions could be made in the precision determination of the

The OPAL collaboration, G. Abbiendi

The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons had been studied using data taken at sqrt(s)_ee=183 GeV and 189 GeV with the OPAL detector at LEP. Results are presented for Ppbar invariant masses, W, in the range 2.15 W< <3.95 GeV. The cross-section measurements are compared with previous data and with recent a

R. J. Mountain

This paper describes the development of a 163-channel Hybrid Photo-Diode (HPD) to be used in the RICH Detector for the BTEV Experiment. This is a joint development project with DEP, Netherlands. It also reports on the development of associated front-end readout electronics based on the va_btev ASIC, undertaken with IDEAS, Norway. Results from bench tests of

Michael T. Anderson

Let (M, g) be an (n+1) dimensional space-time, with bounded curvature with respect to a bounded framing. If (M, g) is vacuum or satisfies a mild condition on the stress-energy tensor, then we show that (M, g) locally admits coordinate systems in which the Lorentz metric is well-controlled in the (space-time) Sobolev space L^{2,p}, for any finite p.

Leor Barack, Amos Ori

We obtain all ``regularization parameters&#39;&#39; (RP) needed for calculating the gravitational and electromagnetic self forces for an arbitrary geodesic orbit around a Schwarzschild black hole. These RP values are required for implementing the previously introduced mode-sum method, which allows a practical calculation of the self force by summing over con

K. P. Tod

Isotropic cosmological singularities are singularities which can be removed by rescaling the metric. In some cases already studied (gr-qc/9903008, gr-qc/9903009, gr-qc/9903018) existence and uniqueness of cosmological models with data at the singularity has been established. These were cosmologies with, as source, either perfect fluids with linear equations

Metin Arik, Dilek Ciftci

In this study a rotationally and translationally invariant metric in Finsler space is investigated. We choose to rewrite the metric in Riemanian space by increasing the dimension of space-time and introducing additional coordinates such that for specific values of these coordinates, the geodesics of the four dimensional Finslerian space-time and six dimensio

Marcello Ortaggio, Jiri Podolsky

A complete family of non-expanding impulsive waves in spacetimes which are the direct product of two 2-spaces of constant curvature is presented. In addition to previously investigated impulses in Minkowski, (anti-)Nariai and Bertotti-Robinson universes, a new explicit class of impulsive waves which propagate in the exceptional electrovac Plebanski-Hacyan sp

Anders M. N. Niklasson

A purification algorithm for expanding the single-particle density matrix in terms of the Hamiltonian operator is proposed. The scheme works with a predefined occupation and requires less than half the number of matrix-matrix multiplications compared to existing methods at low (<10%) and high (>90%) occupancy. The expansion can be used with a fixed chemical

M. Jaime, K. H. Kim, G. Jorge, S. McCall

We studied in detail the low temperature/high magnetic field phases of URu$_{2}$Si$_{2}$ single crystals with specific heat, magnetocaloric effect, and magnetoresistance in magnetic fields up to 45 T. Data obtained down to 0.5 K, and extrapolated to T = 0, show a suppression of the hidden order phase at H$_{o}$(0) = 35.9 $\pm$ 0.35 T and the appearance of a

David M. -T. Kuo, Y. -C. Chang

We show theoretically that a strongly spin-polarized current can be generated in semiconductors by taking advantage of the ferromagnetic phase of a quantum dot array (QDA). A Hubbard model with coupling to leads is used to study the tunneling current of the QDA system as a function of gate voltage. Due to the weak interdot coupling and strong Coulomb repulsi

A. P. Ramirez, G. Lawes, V. Butko, M. A. Subramanian

The dielectric constant of CaCu3Ti4O12 is measured with a different electrode geometry than previous measurements. Similar colossal values are obtained showing that they are &#34;intrinsic&#34; to the material. We show that in braced structures such as CaCu3Ti4O12, a small concentration O(10-3) of defects, which disrupt the bracing and relax between differen

Horst Meyer, Andrei B. Kogan

We analyze the time profile $ΔT(t)$ of the temperature difference, measured across a very compressible supercritical $^3$He fluid layer in its convective state. The experiments were done along the critical isochore in a Rayleigh-Bénard cell after starting the vertical constant heat flow $q$. For $q$ sufficiently well above that needed for the convection onse

A. Badia, C. Lopez

A theoretical framework is presented, which allows to explain many experimental facts related to pinning and cross-flow effects between flux tubes in type-II superconductors. It is shown that critical state principles, in the manner introduced by C. P. Bean for parallel vortex lattices, may be used to describe the observed behavior. We formulate a least acti

H. V. Kruis, I. P. McCulloch, Z. Nussinov, J. Zaanen

We demonstrate that the notion of spin-charge separation as follows from the Tomonaga-Luttinger theory of relativistic fermions does not suffice to completely specify the Luttinger liquid state associated with the fermions of condensed matter physics. The latter carries in addition a form of topological order which can be made visible using non-local correla

M. D. Glinchuk, A. N. Morozovskaya

The theory of size effects of the properties of nanocrystalline ferroelectric ceramic or nanoparticle powder allowing for surface tension and depolarization field is proposed. Surface tension was included into free energy functional and surface energy was expressed via surface tension coefficient. The latter was shown to be dependent on temperature due to it

Hunter King, Ryan White, Iva Maxwell, Narayanan Menon

We have studied the coefficient of restitution, $η$, in normal collisions of a non-rotating sphere on a massive plate for a range of material parameters, impact velocity and sphere size. The measured coefficient of restitution does not monotonically vary with velocity. This effect is due to dynamics that occur during the finite duration of impact: the contac

Vieri Mastropietro

We consider two bidimensional classical Ising models, coupled by a weak interaction bilinear in the energy densities of the two systems; the model contains, as limiting cases, the Ashkin-Teller and the Eight-vertex models for certain values of their parameters. We write the energy-energy correlations and the specific heat as Grassman integrals formally descr

Stéphane Abriet, Dragi Karevski

We study the non-equilibrium time evolution of the average transverse magnetisation and end-to-end correlation functions of the random Ising quantum chain. Starting with fully magnetised states, either in the $x$ or $z$ direction, we compute numerically the average quantities. They show similar behaviour to the homogeneous chain, that is an algebraic decay i

Victor Dotsenko

In this paper we propose a simple mean-field &#34;toy&#34; model for the liquid-glass phase transition. This is the system of $N$ point-like particles confined in a finite volume of a $D$-dimensional space interacting via infinite-range oscillating potential. In the framework of the replica approach it is shown that such a system exhibits the phase transitio

Yoshihide Tanaka, Akira Oguri

We study the effects of disorders on the transport through small interacting systems based on a two-dimensional Hubbard cluster of finite size connected to two noninteracting leads. This system can be regarded as a model for the superlattice of quantum dots or atomic network of the nanometer size. We calculate the conductance at T=0 using the order $U^2$ sel

A. Gerashenko, Y. Furukawa, K. Kumagai, S. Verkhovskii

An influence of the 16O-18O isotope substitutions on magnetic state of perovskite-type manganite (La0.25Pr0.75)0.7Ca0.3MnO3 is studied by 55Mn NMR. Successive cycling with an isochronal exposure at different magnetic fields up to H=8T is used to study the field-induced transition from antiferromagnetic insulating (AFI) state to the ferromagnetic metal (FMM)

Pinar Onder, Ayse Erzan

We study the behaviour of a hydrophobic chain near a hydrophobic boundary in two dimensions, using the decorated lattice model of Berkema and Widom [G.T. Barkema and B. Widom, J. Chem. Phys. 113, 2349 (2000)] to obtain effective, temperature dependent intrachain and chain-boundary interactions. We use these interactions to construct two model hamiltonians wh

D. H. E. Gross

The most complicated phenomena of equilibrium statistics, phase separations and transitions of various order and critical phenomena, can clearly and sharply be seen even for small systems in the topology of the curvature of the microcanonical entropy $S_{B}(E,N)=\ln[W(E,N)]$ as function of the conserved energy, particle number etc.. Also the equilibrium of t

W. Rumsch und W. Nolting

The subject of the present paper is the theoretical description of collective electronic excitations, i.e. spin waves, in the Hubbard-model. Starting with the widely used Random-Phase-Approximation, which combines Hartree-Fock theory with the summation of the two-particle ladder, we extend the theory to a more sophisticated single particle approximation, nam

O. A. Tretiakov, T. Gramespacher, K. A. Matveev

We investigate the transport of electrons through a double-barrier resonant-tunneling structure in the regime where the current-voltage characteristics exhibit bistability. In this regime one of the states is metastable, and the system eventually switches from it to the stable state. We show that the mean switching time grows exponentially as the voltage acr

T. Papenbrock

The one-particle density matrices for hard core bosons in a one-dimensional harmonic trap are computed numerically for systems with up to 160 bosons. Diagonalization of the density matrix shows that the many-body ground state is not Bose-Einstein condensed. The ground state occupation, the amplitude of the lowest natural orbital, and the zero momentum peak h

J. -S. Huang, K. Glazebrook, L. L. Cowie, C. Tinney

We present the K-band local luminosity function derived froma sample of 1056 bright (K<15) K-selected galaxies from the Hawaii-AAO K-band redshift survey. The Hawaii-AAO K-band redshift survey covers 4 equatorial fields with a total area of 8.22 $°^2$. We derive both the non-parametric and Schechter luminosity function from our data, and determine $M^*(K)=-2

Chris J. Willott, Steve Rawlings, Matt J. Jarvis, Katherine M. Blundell

We present K-band imaging of all 49 radio galaxies in the 7C-I and 7C-II regions of the 7C Redshift Survey (7CRS). The low-frequency (151 MHz) selected 7CRS sample contains all sources with flux-densities S_151 > 0.5 Jy in three regions of the sky. We combine the K-band magnitudes of the 7CRS radio galaxies with those from the 3CRR, 6CE and 6C* samples to in

Marcin Sawicki

I describe the principle of using the 1.6um H- spectral feature as a photometric redshift indicator and demonstrate that the technique holds promise by successfully recovering the redshifts of a small sample of z=0-1 galaxies using only their infrared (JHKL) photometry. I then consider the applicability of the technique to the 3.6--8um SIRTF filter set and i

D. P. Bennett, J. Bally, I. Bond, E. Cheng

The Galactic Exoplanet Survey Telescope (GEST) will observe a 2 square degree field in the Galactic bulge to search for extra-solar planets using a gravitational lensing technique. This gravitational lensing technique is the only method employing currently available technology that can detect Earth-mass planets at high signal-to-noise, and can measure the fr

Piercarlo Bonifacio

I use literature data and a new temperature calibration to determine the Li abundances in the globular cluster M 92. Based on the same data, Boesgaard et al. have claimed that there is a dispersion in Li abundances in excess of observational errors. This result has been brought as evidence for Li depletion in metal-poor dwarfs. In the present note I argue th

M. Fellhauer, P. Kroupa

We study the merging of star clusters out of cluster aggregates similar to Knot S in the Antennae on orbits close to the one of omega-Cen by carrying out high resolution numerical N-body simulations. We want to constrain the parameter space which is able to produce merger objects with similar properties as omega-Cen.

A. Tokovinin, S. Baumont, J. Vasquez

Results of 3-month continuous monitoring of turbulence profile and seeing at Cerro Tololo (Chile) in May-July 2002 are presented. Some 28000 low-resolution profiles were measured by a new MASS single-star turbulence monitor, accompanied by seeing data from DIMM. The median seeing was 0.95 arcseconds. The first 500 m contribute 60% to the total seeing, the fr

A. Konopelko, F. Lucarelli, H. Lampeitl, W. Hofmann

In this paper, we present the results of Monte Carlo simulations of atmospheric showers induced by diffuse gamma rays as detected by the high-energy gamma ray astronomy (HEGRA) system of five imaging atmospheric Cerenkov telescopes (IACTs). We have investigated the sensitivity of observations on extended gamma ray emission over the entire field of view of th

U. Hopp, R. E. Schulte-Ladbeck, J. Kerp

We are investigating the hypothesis that Compact High--Velocity Clouds (CHVCs) are the left-over building blocks of Local Group galaxies. To this end, we are searching for their embedded stellar populations using FORS at the VLT. The search is done with single-star photometry in V and I bands, which is sensitive to both, young and old, stellar populations. F

W. F. Thi, K. M. Pontoppidan, E. F. van Dishoeck, E. Dartois

We present direct evidence for CO freeze-out in a circumstellar disk around the edge-on class I object CRBR 2422.8-3423, observed in the M band with VLT-ISAAC at a resolving power R~10,000. The spectrum shows strong solid CO absorption, with a lower limit on the column density of 2.2E18 cm-2. The solid CO column is the highest observed so far, including high

S. Kimeswenger

The &#34;born-again&#34; PNe V605 Aql (A58) and V4344 Sgr (Sakurai) give us the rare chance to follow shell formation and building of the winds in &#34;real-time&#34;. The high carbon abundance, and thus the high dust formation rate, enhances the mechanisms. Thus the timescales are shortened. My data presented here gives a quick look on the results of new ob

M. M. Romanova, G. V. Ustyugova, A. V. Koldoba, R. V. E. Lovelace

Magnetohydrodynamic (MHD) simulations have been used to study disk accretion to a rotating magnetized star with an aligned dipole moment. Quiescent initial conditions were developed in order to avoid the fast initial evolution seen in earlier studies. A set of simulations was performed for different stellar magnetic moments and rotation rates. Simulations ha

D. Nogami, T. Kato, H. Baba

GK Per is a unique cataclysmic variable star which has showed a nova explosion as well as dwarf nova-type outbursts, and has the intermediate-polar nature. We carried out V-band time-resolved photometry and B-band monitoring during the 1996 outburst. This outburst lasted about 60 d and is divided into three parts: the slow rise branch for 35 d, the gradual d

S. K. Saha, V. Chinnappan, L. Yeswanth, P. Anbazhagan

Speckle interferometric technique is employed to record a series of hundreds of short-exposure images of several close binary stars with sub-arcsecond separation through a narrow band filter at the Cassegrain focus of the 2.34 meter (m) Vainu Bappu telescope (VBT), situated at Vainu Bappu Observatory (VBO), Kavalur, India. The data are recorded sequentially

S. K. Saha, V. Chinnappan

A new generation CCD detector called low light level CCD (L3CCD) that performs like an intensified CCD without incorporating a micro channel plate (MCP) for light amplification was procured and tested. A series of short exposure images with millisecond integration time has been obtained. The L3CCD is cooled to about $-80^\circ$ C by Peltier cooling.

P. Focardi, B. Kelm, V. Zitelli, G. Sarti

We present results concerning the occurrence of Seyfert galaxies in a new large sample of Compact Groups (Focardi & Kelm 2002). Seyfert galaxies turn out to be relatively rare (<3%), with a significant dominance of Sy2. Seyferts are preferentially associated to Compact Groups displaying relatively high velocity dispersion and a large number of neighbours. Th

Cristian Predescu, J. D. Doll

By means of the Ito-Nisio theorem, we introduce and discuss a general approach to series representations of path integrals. We then argue that the optimal basis for both ``primitive&#39;&#39; and partial averaged approaches is the Wiener sine-Fourier basis. The present analysis also suggests a new approach to improving the convergence of primitive path integ

A. Dakhama, B. Lakshmi, D. Heiman

The magnetic, transport, and structural properties of (Ga,Cr)As are reported. Zincblende Ga$_{1-x}$Cr$_{x}$As was grown by low-temperature molecular beam epitaxy (MBE). At low concentrations, x$\sim$0.1, the materials exhibit unusual magnetic properties associated with the random magnetism of the alloy. At low temperatures the magnetization M(B) increases ra

Hwei-Jang Yo, Thomas W. Baumgarte, Stuart L. Shapiro

We experiment with modifications of the BSSN form of the Einstein field equations (a reformulation of the ADM equations) and demonstrate how these modifications affect the stability of numerical black hole evolution calculations. We use excision to evolve both non-rotating and rotating Kerr-Schild black holes in octant and equatorial symmetry, and without an

A. V. Penskoi, A. P. Veselov

We show that the continuous limit of a wide natural class of the right-invariant discrete Lagrangian systems on the Virasoro group gives the family of integrable PDE&#39;s containing Camassa-Holm, Hunter-Saxton and Korteweg-de Vries equations. This family has been recently derived by Khesin and Misiolek as Euler equations on the Virasoro algebra for $H^1_{α,

Ph. Brax, C. van de Bruck, A. -C. Davis, C. S. Rhodes

We study cosmological consequences of non-constant brane world moduli in five dimensional brane world models with bulk scalars and two boundary branes. We focus on the case where the brane tension is an exponential function of the bulk scalar field, $U_b \propto \exp{(αϕ)}$. In the limit $α\to 0$, the model reduces to the two-brane model of Randall-Sundrum,

Paul S. Aspinwall, R. Paul Horja, Robert L. Karp

We analyze the link between the occurrence of massless B-type D-branes for specific values of moduli and monodromy around such points in the moduli space. This allows us to propose a classification of all massless B-type D-branes at any point in the moduli space of Calabi-Yau&#39;s. This classification then justifies a previous conjecture due to Horja for th

Hiromitsu Takayanagi, Tadashi Takayanagi

We investigate the giant gravitons in the maximally supersymmetric IIB pp-wave from several viewpoints: (i) the dynamics of D3-branes, (ii) the world-sheet description and (iii) the correlation functions in the dual N=4 Yang-Mills theory. In particular, we derive the BPS equation of a D3-brane with magnetic flux, which is equivalent to multiple D-strings, an

M. E. J. Newman

We study assortative mixing in networks, the tendency for vertices in networks to be connected to other vertices that are like (or unlike) them in some way. We consider mixing according to discrete characteristics such as language or race in social networks and scalar characteristics such as age. As a special example of the latter we consider mixing accordin

Carlos Gershenson

In this thesis I present a virtual laboratory which implements five different models for controlling animats: a rule-based system, a behaviour-based system, a concept-based system, a neural network, and a Braitenberg architecture. Through different experiments, I compare the performance of the models and conclude that there is no &#34;best&#34; model, since

V. Chiochia

The latest results of beauty quark production measurements at HERA are presented. New measurements have been obtained both in the photoproduction and the deep inelastic scattering regimes. The results were compared with the NLO QCD calculations.

R. S. Gonnelli, D. Daghero, G. A. Ummarino, V. A. Stepanov

Directional point-contact spectroscopy measurements were performed for the first time in state-of-the-art MgB_2 single crystals. The selective suppression of the superconductivity in the &#34;pi&#34; band by means of a suitable magnetic field allowed separating the partial contribution of each band to the total point-contact conductance. By fitting the parti

L. B. Weinstein, R. Niyazov

We have measured the $^3$He(e,e$&#39;$pp)n{} reaction in the Jefferson Lab CLAS with 2.2 and 4.4 GeV electrons. We looked at the energy distribution of events with all three nucleons at high momentum (p > 250 MeV/c). This distribution has peaks where two nucleons each have 20% or less of the energy transfer (ie: the third or `leading&#39; nucleon carries mos

Wafia Bensalam, David London, Nita Sinha, Rahul Sinha

We study the spin polarizations of both tau leptons in the decay b -> s tau+ tau-. In addition to the polarization asymmetries involving a single tau, we construct asymmetries for the case where both polarizations are simultaneously measured. We also study forward-backward asymmetries with polarized tau&#39;s. We find that a large number of asymmetries are p

Filip Franco-Sollova, Tatiana A. Ivanova

The Yang-Mills (YM) and self-dual Yang-Mills (SDYM) equations on the noncommutative Euclidean four-dimensional space are considered. We introduce an ansatz for a gauge potential reducing the noncommutative SDYM equations to a difference form of the Nahm equations. By constructing solutions to the difference Nahm equations, we obtain solutions of the noncommu

V. Suneeta

We discuss issues relating to the topology of Euclidean de Sitter space. We show that in (2+1) dimensions, the Euclidean continuation of the`causal diamond&#39;, i.e the region of spacetime accessible to a timelike observer, is a three-hemisphere. However, when de Sitter entropy is computed in a `stretched horizon&#39; picture, then we argue that the correct

Robert de Mello Koch, Antal Jevicki, Joao P. Rodrigues

We develop a systematic procedure for deriving canonical string field theory from large N matrix models in the Berenstein-Maldacena-Nastase limit. The approach, based on collective field theory, provides a generalization of standard string field theory.

V. A. Saleev, D. V. Vasin

We compare the predictions of the collinear parton model and the k_T-factorization approach in JΨand D^\star meson photoproduction at HERA energies. It is shown that obtained in the both approaches D^\star meson spectra over p_T and ηas well as JΨmeson p_T- and z-spectra are very different. The predictions obtained in the k_T-factorization approach are agree

P. G. Perez-Gonzalez, A. Gil de Paz, J. Zamorano, J. Gallego

We present the integrated properties of the stellar populations in the Universidad Complutense de Madrid Survey galaxies. Applying the techniques described in the first paper of this series, we derive ages, burst masses and metallicities of the newly-formed stars in our sample galaxies. The population of young stars is responsible for the Halpha emission use

P. G. Perez-Gonzalez, A. Gil de Paz, J. Zamorano, J. Gallego

We present an analysis of the integrated properties of the stellar populations in the Universidad Complutense de Madrid Survey of Halpha-selected galaxies. In this paper, the first of a series, we describe in detail the techniques developed to model star-forming galaxies using a mixture of stellar populations, and taking into account the observational uncert

Nobuhiro Maekawa, Toshifumi Yamashita

We show that in the framework of grand unified theory (GUT) with anomalous $U(1)_A$ gauge symmetry, the success of the gauge coupling unification in the minimal SU(5) GUT is naturally explained, even if the mass spectrum of superheavy fields does not respect SU(5) symmetry. Because the unification scale for most realizations of the theory becomes smaller tha

S. Descotes-Genon, C. T. Sachrajda

We study the radiative decay B -> gamma l nu_l in the framework of QCD factorization. We demonstrate explicitly that, in the heavy-quark limit and at one-loop order in perturbation theory, the amplitude does factorize, i.e. that it can be written as a convolution of a perturbatively calculable hard-scattering amplitude with the (non-perturbative) light-cone

K. Nomura, O. Miyamura, T. Umeda, H. Matsufuru

We study charmonium correlators at finite temperature in quenched anisotropic lattice QCD. The smearing technique is applied to enhance the low energy part of the correlator. We use two analysis procedures: the maximum entropy method for extraction of the spectral function without assuming specific form, as an estimate of the shape of spectral function, and

Tomohiro Matsuda

When one constructs specific models with the fundamental scale as low as the TeV scale, there arise many difficulties. In this paper we examine the hybrid inflation due to bulk scalar fields, which has been proposed to solve the problem of fine-tuning in producing density perturbations. We find that the Kaluza-Klein modes play significant roles, which enhanc

Daisuke Kawata, Brad K. Gibson

We study the chemo-dynamical evolution of elliptical galaxies and their hot X-ray emitting gas using high-resolution cosmological simulations. Our Tree N-body/SPH code includes a self-consistent treatment of radiative cooling, star formation, supernovae feedback, and chemical enrichment. We present a series of LCDM cosmological simulations which trace the sp

Vladimir S. Malinovsky, Paul R. Berman

We consider momentum transfer using frequency-chirped standing wave fields. Novel atom-beam splitter and mirror schemes based on Bragg scattering are presented. It is shown that a predetermined number of photon momenta can be transferred to the atoms in a single interaction zone.

J. M. C. Malbouisson, B. Baseia

The degree of nonclassicality of states of a field mode is analysed considering both phase-space and distance-type measures of nonclassicality. By working out some general examples, it is shown explicitly that the phase-space measure is rather sensitive to superposition of states, with finite superpositions possessing maximum nonclassical depth (the highest

Ph. Jacquod, I. Adagideli, C. W. J. Beenakker

The Loschmidt Echo M(t) (defined as the squared overlap of wave packets evolving with two slightly different Hamiltonians) is a measure of quantum reversibility. We investigate its behavior for classically quasi-integrable systems. A dominant regime emerges where M(t) ~ t^{-alpha} with alpha=3d/2 depending solely on the dimension d of the system. This power

Dominic W. Berry, Barry C. Sanders

We analyse quantum teleportation (QT) and entanglement swapping (ES) for spin systems. If the permitted operations are restricted to the Ising interaction, plus local rotations and spin measurements, high-fidelity teleportation is achievable for quantum states that are close to the maximally weighted spin state. ES is achieved, and is maximized for a combina

D. W. Berry, H. M. Wiseman

We analyze the problem of quantum-limited estimation of a stochastically varying phase of a continuous beam (rather than a pulse) of the electromagnetic field. We consider both non-adaptive and adaptive measurements, and both dyne detection (using a local oscillator) and interferometric detection. We take the phase variation to be \dotϕ= \sqrtκξ(t), where ξ(

A. Blanco, V. Chepel, R. Ferreira-Marques, P. Fonte

In this study we address the feasibility and main properties of a positron emission tomograph (PET) based on RPCs. The concept, making use of the converter-plate principle, takes advantage of the intrinsic layered structure of RPCs and its simple and economic construction. The extremely good time and position resolutions of RPCs also allow the TOF-PET imagin

Shlomo E. Sklarz, Inbal Friedler, David J. Tannor, Yehuda B. Band

It has been proposed that the adiabatic loading of a Bose-Einstein Condensate (BEC) into an optical lattice via the Mott-insulator transition can be used to initialize a quantum computer [D. Jaksch, {\it et al.}, Phys. Rev. Lett. {\bf 81}, 3108 (1998)]. The loading of a BEC into the lattice without causing band excitation is readily achievable; however, unle

W. Woelfli, W. Baltensperger

The calculated values of Earth&#39;s inclinations during the cold events in the 500 kyr climate record of Devils Hole show a correlation: they cluster in the regions around 1 and 2 degrees. The Devils Hole record has been chosen, since it was dated by absolute methods. Other climate records covering the same period also have a reduced number of cold events b

J. S. Kim, C. D. Nantista, D. H. Whittum, R. H. Miller

We present a non-invasive, resonant cavity based approach to beam emittance measurement of a shot-to-shot non-circular beam pulse of multi-bunches. In a resonant cavity, desired field components can be enhanced up to Q_L_lambda/pi, where Q_L_lambda is the loaded Q of the resonance mode lambda, when the cavity resonant mode matches with the beam operating fre

Sandra S. Padula

The effects of opacity of the nuclei together with a blackbody type of emission along the system history are considered as a means to explain the ratio $R_{out}/R_{sid}$ observed by STAR and PHENIX collaborations at RHIC. Within our model, no flow is required to explain the data trend of this ratio for large surface emissivities.

A. Amghar, B. Desplanques

The effect of non-locality in the NN interaction with an off-energy shell character has been studied in the past in relation with the possibility that some models could be approximately phase-shifts equivalent. This work is extended to a non-locality implying terms that involve an anticommutator with the operator p^2. It includes both scalar and tensor compo

J. M. Sampaio, K. Langanke, G. Martinez-Pinedo, E. Kolbe

Electron capture rates on neutron-rich nuclei (A>65) were calculated within the Random Phase Approximation with partial number formalism, including allowed and forbidden transitions. The partial occupation numbers were provided as a function of temperature by Shell-Model Monte Carlo calculations, including an pairing+quadrupole interaction. Capture rates on

Sham S. Malik, A. K. Jain, S. R. Jain

Following the semiclassical formalism of Strutinsky et al., we have obtained the complete eigenvalue spectrum for a particle enclosed in an infinitely high spheroidal cavity. Our spheroidal trace formula also reproduces the results of a spherical billiard in the limit $η\to1.0$. Inclusion of repetition of each family of the orbits with reference to the large