April 2001 arXiv papers — page 4

Philip Phillips, Denis Dalidovich

Transport data on Bi, MoGe, and PbBi/Ge homogeneously-disordered thin films demonstrate that the critical resistivity, $R_c$, at the nominal insulator-superconductor transition is linearly proportional to the normal sheet resistance, $R_N$. In addition, the critical magnetic field scales linearly with the superconducting energy gap and is well-approximated b

Sunggeun Lee, Sang-Jin Sin

Using the AdS/CFT correspondence we study UV behavior of Wilson loops in various noncommutative gauge theories. We get an area law in most cases and try to identify its origin. In D3 case, we may identify the the origin as the D1 dominance over the D3: as we go to the boundary of the AdS space, the effect of the flux of the D3 charge is highly suppressed, wh

Pablo Ramacher

We study the geometry of families of hypersurfaces in Eguchi-Hanson space that arise as complex line bundles over curves in $S^2$ and are three-dimensional, non-compact Riemannian manifolds, which are foliated in Hopf tori for closed curves. They are negatively curved, asymptotically flat spaces, and we compute the complete three-dimensional curvature tensor

Kazuki Ohmori

We construct a kink solution on a non-BPS D-brane using Berkovits' formulation of superstring field theory in the level truncation scheme. The tension of the kink reproduces 95% of the expected BPS D-brane tension. We also find a lump-like solution which is interpreted as a kink--antikink pair, and investigate some of its properties. These results may be

Y. M. Cho, Ishwaree P. Neupane, P. S. Wesson

A general solution to the Einstein field equations with Gauss-Bonnet(GB) term in the $AdS_5$ bulk background implies that the GB coupling $α$ can take either sign (+ or -), though a positive $α$ will be more meaningful. By considering linearized gravity with the GB term in the Randall-Sundrum(RS) a singular 3-brane model, we study the gravitational interacti

Dileep P. Jatkar, Radhika Vathsan

We study soliton solutions in scalar field theory with a variety of unbounded potentials. A subset of these potentials have Gaussian lump solutions and their fluctuation spectrum is governed by the harmonic oscillator problem. These lumps are unstable with one tachyonic mode. Soliton solutions in several other classes of potentials are stable and are of kink

Tohru Kawamoto, Madoka Tokumoto, Hirokazu Sakamoto, Kenji Mizoguchi

We have theoretically studied pressure effects on molecular ferromagnet C$_{60}$ complexes with tetrakis (dimethylamino) ethylene (TDAE), particularly the pressure-induced depression of the Curie temperature. The observed behavior is well simulated with our model based on a charge transfer induced intramolecular Jahn-Teller distortion and an intermolecular c

Surujhdeo Seunarine, Douglas W. McKay

We study the rate of true vacuum bubble nucleation numerically for a phi^4 field system coupled to a source of thermal noise. We compare in detail the cases of additive and multiplicative noise. We pay special attention to the choice of initial field configuration, showing the advantages of a version of the quenching technique. We advocate a new method of ex

A. B. Adib, C. A. S. Almeida

It was recently proposed a novel discretization for nonlinear Klein-Gordon field theories in which the resulting lattice preserves the topological (Bogomol'nyi) lower bound on the kink energy and, as a consequence, has no Peierls-Nabarro barrier even for large spatial discretizations (h~1.0). It was then suggested that these ``topological discrete system

G. Teklemariam, E. M. Fortunato, M. A. Pravia, T. F. Havel

We report the implementation of a three-spin quantum disentanglement eraser on a liquid-state NMR quantum information processor. A key feature of this experiment was its use of pulsed magnetic field gradients to mimic projective measurements. This ability is an important step towards the development of an experimentally controllable system which can simulate

Edward Farhi, Jeffrey Goldstone, Sam Gutmann, Joshua Lapan

A quantum system will stay near its instantaneous ground state if the Hamiltonian that governs its evolution varies slowly enough. This quantum adiabatic behavior is the basis of a new class of algorithms for quantum computing. We test one such algorithm by applying it to randomly generated, hard, instances of an NP-complete problem. For the small examples t

Alexander Yu. Vlasov

In the paper is discussed complete probabilistic description of quantum systems with application to multiqubit quantum computations. In simplest case it is a set of probabilities of transitions to some fixed set of states. The probabilities in the set may be represented linearly via coefficients of density matrix and it is very similar with description using

R. Srikanth

The amount of information transferred during standard quantum teleportation or remote state preparation is equal to the preparation information of the transmitted state, rather than the classical communication required by respective protocol. This is shown by noting that the information required to specify the operation that verifies the transmitted state is

S. Mendoza

The collision of a plane parallel shock wave with a plane parallel cloud of uniform density is analysed for the case in which magnetic fields and radiative losses are not considered. General analytic solutions are discussed for the case in which the density of the cloud is greater than that of the surrounding environment. This problem generalises one of the

Elmir Dermendjiev

It is shown that the results of Buttiker and Landauer on the traversal time of quantum tunneling through a potential barrier are in agreement with the principle of relativity. Also, they are consistent with the data on the life-time of nuclear particles that decay in flight. PACS number: 03.30, Special Relativity

M. Nieszporski, A. Doliwa, P. M. Santini

We present the constraint for the discrete Moutard equation which gives the integrable discretization of the Bianchi-Ernst system. We also derive the discrete analogue of the Bianchi transformation between solutions of such a system (the Darboux-Backlund transformation in soliton terminology). We finally obtain the superposition of discrete Bianchi transform

C. R. Handy, D. Khan, Xiao-Qian Wang, C. J. Tymczak

The recent work of Delabaere and Trinh (2000 J. Phys. A 33 8771) discovered the existence of ${\cal P}{\cal T}$-symmetry breaking, complex energy, $L^2$ solutions for the one dimensional Hamiltonian, $P^2+iX^3+iαX$, in the asymptotic limit, $α\to -\infty$. Their asymptotic analysis produced questionable results for moderate values of $α$. We can easily confi

C. R. Handy

The Eigenvalue Moment Method (EMM), Handy (2001), Handy and Wang (2001)) is applied to the $H_α\equiv P^2 + iX^3 + iαX$ Hamiltonian, enabling the algebraic/numerical generation of converging bounds to the complex energies of the $L^2$ states, as argued (through asymptotic methods) by Delabaere and Trinh (J. Phys. A: Math. Gen. {\bf 33} 8771 (2000)).

C. R. Handy

Recent investigations by Bender and Boettcher (Phys. Rev. Lett 80, 5243 (1998)) and Mezincescu (J. Phys. A. 33, 4911 (2000)) have argued that the discrete spectrum of the non-hermitian potential $V(x) = -ix^3$ should be real. We give further evidence for this through a novel formulation which transforms the general one dimensional Schrodinger equation (with

Yash Puri, Thomas Ward

We give necessary and sufficient conditions for a sequence to be exactly realizable as the sequence of numbers of periodic points in a dynamical system. Using these conditions, we show that no non-constant polynomial is realizable, and give some conditions on realizable binary recurrence sequences. Realization in rate is always possible for sufficiently rapi

Brian Harbourne, Joaquim Roé

Conjectures for the Hilbert function of the m-th symbolic power of the ideal of n general points of P2 are verified for infinitely many m for each square n > 9, using an approach developed by the authors in a previous paper. In those cases that n is even, conjectures for the resolution are also verified. Previously, by work of Evain (for the Hilbert function

Juhani Bonsdorff

We define a Fourier-Mukai transform for Higgs bundles on smooth curves and study its properties. It is shown that the transform of a stable zero-degree Higgs bundle is an algebraic vector bundle on the cotangent bundle of the Jacobian of the curve. We show that this transformed bundle admits a natural extension to an algebraic vector bundle over a projective

Yuri G. Prokhorov

We prove that the only accumulation points of the set $T_3$ of all three-dimensional log canonical thresholds in the interval $[1/2,1]$ are $1/2+1/n$, where $n\in\ZZ$, $n\ge 3$.

Wadim Zudilin

We present several results on the number of irrational and linear independent values among $ζ(s),ζ(s+2),...,ζ(s+2n)$, where $s>2$ is an odd integer and $n>0$ is an integer. The main tool in our proofs is a certain generalization of Rivoal's construction (math.NT/0008051, math.NT/0104221).

Jorge A. Guccione, Juan J. Guccione

We prove the existence of two long exact sequences relating the Hochschild cohomology of a triangular matrix algebra with the Hochschild homology of its component subalgebras. We also study the structure of the maps of the first sequence.

Martin Cederwall, Bengt E. W. Nilsson, Dimitrios Tsimpis

Using superspace techniques, the complete and most general action of D=10 super-Yang--Mills theory is constructed at the alpha'^2 level. No other approximations, e.g., keeping only a subset of the allowed derivative terms, are used. The Lorentz structure of the alpha'^2 corrections is completely determined, while (depending on the gauge group) there is some

Dmitriy V. Uvarov

The main goal of this paper is the manifestly covariant derivation of the classical relation between the gauge-fixed Grassmann variables of the NSR string and the Type II GS superstring. To this end we analyze the superembedding equation for the Type II superstring to derive the relation between the original variables of the NSR string and the Type II GS sup

A. A. Slavnov

A new renormalization scheme for theories with nontrivial internal symmetry is proposed. The scheme is regularization independent and respects the symmetry requirements.

B. L. Julia

In this short review we compare the rigid Noether charges to topological gauge charges. One important extension is that one should consider each boundary component of spacetime independently. The argument that relates bulk charges to surface terms can be adapted to the perfect fluid situation where one can recognise the helicity and enstrophies as Noether ch

E. Boos, M. Dubinin, A. Pukhov, M. Sachwitz

Single top quark cross section evaluations for the complete sets of tree-level diagrams in the $e^+ e^-$, $e^- e^-$, $γe$ and $γγ$ modes of the next linear collider with unpolarized and polarized beams are performed within the Standard Model and beyond. From comparison of all possibilities we conclude that the process $γ_+ e^-_L \to e^- t \bar b$ is extremel

M. Dasgupta, G. P. Salam

We discuss issues related to the resummation of non-global observables in QCD, those that are sensitive to radiation in only a part of phase space. Examples of such observables are certain single-hemisphere event shapes in e+e- and DIS. Compared to global observables (those sensitive to all emissions, e.g. the e+e- thrust) a new class of single-logarithmic t

The DELPHI Collaboration, P. Abreu

A measurement of the W mass and width has been performed by the DELPHI collaboration using the data collected during 1998. The data sample has an integrated luminosity of 155 pb^{-1} and an average centre-of-mass energy of 188.6 GeV. Results are obtained by applying the method of direct reconstruction of the mass of the W from its decay products in both the

Yutaka Ushiroda

We studied radiative B meson decays with the Belle detector. We measured the following branching fractions; Br(B->K*0(892)γ) = (49.6 \pm 6.7 \pm 4.5) x 10^{-6}, Br(B->K*+(892)γ) = (38.9 \pm 9.3 \pm 4.1) x 10^{-6}, Br(B->Xsγ) = (3.39 \pm 0.53 \pm 0.42 +0.51-0.55) x 10^{-4}. We also set an upper limit for B -> ργas Br(B->ργ)/Br(B->K*(892)γ) < 0.19 at 90% confi

Ruth Lazkoz, Jose M M Senovilla, Raul Vera

The Bel tensor is divergence-free in some important cases leading to the existence of conserved currents associated to Killing vectors analogously to those of the energy-momentum tensor. When the divergence of the Bel tensor does not vanish one can study the interchange of some quantities between the gravitational and other fields obtaining mixed total conse

G. Bergqvist, J. M. M. Senovilla

A rank-n tensor on a Lorentzian manifold V whose contraction with n arbitrary causal future directed vectors is non-negative is said to have the dominant property. These tensors, up to sign, are called causal tensors, and we determine their general properties in dimension N. We prove that rank-2 tensors which map the null cone on itself are causal. It is kno

Bijan Saha, G. N. Shikin

We consider a system of nonlinear spinor and scalar fields with minimal coupling in general relativity. The nonlinearity in the spinor field Lagrangian is given by an arbitrary function of the invariants generated from the bilinear spinor forms $S= {\bar ψ} ψ$ and $P=i {\bar ψ} γ^5 ψ$; the scalar Lagrangian is chosen as an arbitrary function of the scalar in

T. Harko, K. S. Cheng

Exact solutions of the gravitational field equations for a mixture of a null charged strange quark fluid and radiation are obtained in a Vaidya space-time. The conditions for the formation of a naked singularity are analyzed by considering the behavior of radial geodesics originating from the central singularity.

D. Lipp, M. Schneider, A. Gladun, S. -L. Drechsler

The temperature and magnetic field dependence of the specific heat cp(T,H) in the superconducting mixed state as well as the upper critical field Hc2(T) have been measured for polycrystalline Y_xLu_{1-x}Ni_2B_2C and Y(Ni_{1-y}Pt_y)_2B_2C samples. The linear-in-T electronic specific heat contribution gamma(H)T exhibits significant deviations from the usual li

Ernst Helmut Brandt

Previous continuum theory of type-II superconductors of various shapes with and without vortex pinning in an applied magnetic field and with transport current, is generalized to account for a finite London penetration depth lambda. This extension is particularly important at low inductions B, where the transition to the Meissner state is now described correc

D. I. Khomskii

In this paper I give a short review of some properties of the colossal magnetoresistance manganites, connected with the orbital degrees of freedom. Ions Mn{3+}, present in most of these compounds, have double orbital degeneracy and are strong Jahn-Teller ions, causing structural distortions and orbital ordering. Mechanisms leading to such ordering are shortl

L. Didukh, O. Kramar

In the paper a possibility of metallic ferromagnetic state realization in a generalized Hubbard model with more complete accounting of electron-electron interactions, in particular, the correlated hopping and exchange interaction integrals is investigated. Recently obtained by means of mean-field approximation single electron energy spectrum is used for the

Michael Thorwart, Peter Hänggi

The dynamics of a quantum XOR gate operation in a two-qubit system being coupled to a bath of quantum harmonic oscillators is investigated. Upon applying the numerical quasiadiabatic propagator path integral method, we obtain the numerically precise time-resolved evolution of this interacting two-qubit system in presence of time-dependent external fields wit

K. Gianno&#39;, A. V. Sologubenko, H. R. Ott, A. D. Bianchi

The thermoelectric power S and the thermal conductivity k of stoichiometric and vacancy-doped CaB6 have been measured between 5 and 300 K. The thermopower of both materials is surprisingly large at room temperature. Across the whole covered temperature range, S is negative and the temperature dependence is most likely dictated by band-structure effects. The

A. V. Bondarenko, A. A. Prodan, Yu. T. Petrusenko, V. N. Borisenko

We report on drastic change of vortex dynamics with increase of quenched disorder: for rather weak disorder we found a single vortex creep regime, which we attribute to a Bragg-glass phase, while for enhanced disorder we found an increase of both the depinning current and activation energy with magnetic field, which we attribute to entangled vortex phase. We

Mojca Cepic, Bostjan Zeks

The free energy of antiferroelectric liquid crystal which takes into account polar order explicitly is presented. Steric, van der Waals, piezoelectric and flexoelectric interactions to the nearest layers and dipolar electrostatic interactions to the nearest and to the next nearest layers induce indirect tilt interactions with chiral and achiral properties, w

A. A. Fraerman, M. V. Sapozhnikov

Magnetic properties of 2D systems of magnetic nanoobjects (2D regular lattices of the magnetic nanoparticles or magnetic nanostripes) are considered. The analytical calculation of the hysteresis curve of the system with interaction between nanoobjects is provided. It is shown that during the magnetization reversal system passes through a number of metastable

H. W. Diehl, R. K. Zia

It is shown that the interface model introduced in Phys. Rev. Lett. 86, 2369 (2001) violates fundamental symmetry requirements for vanishing gravitational acceleration $g$, so that its results cannot be applied to critical properties of interfaces for $g\to 0$.

A. H. Li, X. L. Wang, M. Ionescu, S. Soltonian

The fabrication, characterisation, and superconductivity of MgB2 thick films grown on stainless steel substrate were studied. XRD, SEM, and magnetic measurements were carried out. It was found that the MgB2 thick films can be fast formed by heating samples to 660 oC then immediately cooling down to room temperature. XRD shows above 90% MgB2 phase and less th

O. M. Stoll, A. Wehner, R. P. Huebener, M. Naito

We have investigated the vortex-glass transition for the cuprate superconductor Nd2-xCexCuOy (NCCO) in the region of low temperatures (T < 4.4 K) and moderate up to high magnetic fields (3 T < B < 5 T) compared to the upper critical field Bc2 (Bc2 approx. 6 T for NCCO). We analyzed our data using the vortex-glass theory and found an excellent scaling behavio

Jurij Smakov, Ivar Martin, Alexander V. Balatsky

Localized spin states in conventional superconductors at low temperatures are expected to have long decoherence time due to the strong suppression of spin relaxation channels. We propose a scanning tunneling microscopy (STM) experiment allowing the direct measurement of the decoherence time of a single spin in a conventional superconductor. The experimental

A. D. Kiselev, O. Yaroshchuk, Yu. Zakrevskyy, J. Stumpe

The photoinduced 3D orientational structures in the films of liquid crystalline polyester, containing azobenzene side groups, are studied both experimentally and theoretically. By using the null ellipsometry and the UV absorption methods, preferential in-plane alignment of the azobenzene fragments and in-plane reorientation under irradiation with polarized U

T. Ueta, M. Meixner, P. M. Hinz, W. F. Hoffmann

We report sub-arcsecond imaging of extended mid-infrared emission from a proto-planetary nebula (PPN), \iras 22272+5435, performed at the MMT observatory with its newly upgraded 6.5 m aperture telescope and at the Keck observatory. The mid-infrared emission structure is resolved into two emission peaks separated by $0\arcsec.5 - 0\arcsec.6$ in the MMT 11.7 $

T. J. Davidge, Sidney van den Bergh

We have used the adaptive optics system on the Canada-France-Hawaii Telescope to study a field 6 arcmin from the center of the heavily obscured elliptical galaxy Maffei 1. Our near diffraction-limited H and K&#39; images reveal an excess population of objects with respect to a background field, and we conclude that the asymptotic giant branch tip (AGB-tip) i

Douglas Scott, Martin White, Joanne D. Cohn, Elena Pierpaoli

The cold dark matter paradigm has been extremely successful for explaining a wide range of cosmological phenomena. Nevertheless, since evidence for non-baryonic dark matter remains indirect, all reasonable alternatives should be explored. One proposed idea, involving a fundamental acceleration scale a_0 = 1-2e-10 m/s^2, is called MOdified Newtonian Dynamics

T. J. Davidge

JHK images obtained with the Canada-France-Hawaii Telescope (CFHT) Adaptive Optics Bonnette (AOB) are used to investigate the near-infrared photometric properties of red giant branch (RGB) and horizontal branch (HB) stars in eight metal-poor globular clusters with R_GC < 2 kpc. The slope of the RGB on the (K, J-K) CMDs confirms the metal-poor nature of these

M. D. Snellgrove, J. C. B. Papaloizou, R. P. Nelson

We consider two protoplanets gravitationally interacting with each other and a protoplanetary disc. The two planets orbit interior to a tidally maintained disc cavity while the disc interaction indices inward migration. When the migration is slow enough, the more rapidly migrating outer protoplanet approaches and becomes locked in a 2:1 commensurability with

E. Branchini, W. Freudling, L. N. Da Costa, C. S. Frenk

We compare the peculiar velocities derived from the I-band Tully-Fisher (TF) relation for 989 field spiral galaxies in the SFI catalogue with the predicted velocity field derived from the IRAS PSCz galaxy redshift survey. We assume linear gravitational instability theory and apply the maximum likelihood technique, VELMOD, to SFI galaxies within cz<6000 km/s.

L. J. Smith, J. S. Gallagher

We present high dispersion echelle spectroscopy of the very luminous, young super star cluster (SSC) `F&#39; in M82, obtained with the 4.2-m William Herschel Telescope (WHT), for the purpose of deriving its dynamical mass and assessing whether it will survive to become an old globular cluster. We measure a stellar velocity dispersion of 13.4 +/- 0.7 km/s, a

K O&#39;Brien, K Horne

In X-ray binaries much of the optical/UV emission arises from X-rays reprocessed by material in the accretion disk, stream and the companion star. The resulting reprocessed variability will be delayed in time with respect to the X-ray variability by an amount depending on the position of the reprocessing regions. We can determine a range of time-delays prese

F. Mannucci, F. Basile, B. M. Poggianti, A. Cimatti

We have observed 28 local galaxies in the wavelength range between 1 and 2.4 mic in order to define template spectra of the normal galaxies along the Hubble sequence. Five galaxies per morphological type were observed in most cases, and the resulting RMS spread of the normalized spectra of each class, including both intrinsic differences and observational un

Nandini Nag, Somenath Chakrabarty

Some special features of magnetically deformed multi-electron atoms in the crustal region of strongly magnetized neutron stars (magnetars) are studied with the relativistic version of semi-classical Thomas-Fermi model. An analytical solution of Poisson&#39;s equation with cylindrical symmetry is obtained. The variation of atomic dimension with magnetic field

Mark Sullivan, Bahram Mobasher, Ben Chan, Lawrence Cram

We present results from a decimetric radio survey undertaken with the Very Large Array as part of a longer term goal to inter-compare star formation and dust extinction diagnostics, on a galaxy by galaxy basis, for a representative sample of nearby galaxies. For our survey field, Selected Area 57, star formation rates derived from 1.4GHz luminosities are com

M. Busso, R. Gallino, D. L. Lambert, C. Travaglio

We present the results of s-process nucleosynthesis calculations for AGB stars of different metallicities and initial masses. The computations were based on previously published stellar evolutionary models that account for the III dredge up phenomenon occurring late on the AGB. Neutron production is driven by the 13C(alpha,n)16O reaction during the interpuls

Kelly Holley-Bockelmann

Supermassive black holes can be seen as an agent of galaxy transformation. In particular, a supermassive black hole can cause a triaxial galaxy to evolve toward axisymmetry by inducing chaos in centrophilic orbit families. This is one way in which a single supermassive black hole can induce large-scale changes in the structure of its host galaxy -- changes o

Philip R. Maloney, J. Bland-Hawthorn

Observations with the Extreme Ultraviolet Explorer satellite are purported to show extreme ultraviolet (EUV) and soft X-ray excesses in several clusters of galaxies (Bonamente, Lieu & Mittaz 2001). If interpreted as thermal emission, this would imply the presence of warm (T\sim 10^6 K) gas in these clusters with a mass comparable to that of gas at coronal te

Rudy Wijnands, Mariano Mendez, Jon M. Miller, Jeroen Homan

We present a detailed study of the 5 Hz quasi-periodic oscillation (QPO) recently discovered in the bright X-ray transient and black-hole candidate GRS 1739-278 (Borozdin & Trudolyubov 2000) during a Rossi X-ray Timing Explorer observation taken on 1996 March 31. In total 6.6 ksec of on-source data were obtained, divided in two data sets of 3.4 and 3.2 ksec

Yael Naze, You-Hua Chu, Sean D. Points, Charles W. Danforth

Massive stars are expected to produce wind-blown bubbles in the interstellar medium; however, ring nebulae, suggesting the existence of bubbles, are rarely seen around main-sequence O stars. To search for wind-blown bubbles around main-sequence O stars, we have obtained high-resolution Hubble Space Telescope WFPC2 images and high-dispersion echelle spectra o

Sharada Iyer Dutta, Mary Hall Reno, Ina Sarcevic

We evaluate the upward shower and muon event rates for two characteristic four neutrino mixing models for extragalactic neutrinos, as well as for the atmospheric neutrinos, with energy thresholds of 1 TeV, 10 TeV and 100 TeV. We show that by comparing the shower to muon event rates, one can distinguish between oscillation and no-oscillation models. By measur

Frederic Leblond

We study how the geometry of the large extra dimensions may affect field theory results on a three-brane. More specifically, we compare cross sections for graviton emission from a brane when the internal space is a N-torus and a N-sphere for N=2 to 6. The method we present can be used for other smooth compact geometries. We find that the ability of high ener

J. Gamboa, M. Loewe, F. Mendez, J. C. Rojas

The conditions under which noncommutative quantum mechanics and the Landau problem are equivalent theories is explored. If the potential in noncommutative quantum mechanics is chosen as $V= Ω\aleph$ with $\aleph$ defined in the text, then for the value ${\tilde θ} = 0.22 \times 10^{-11} cm^2$ (that measures the noncommutative effects of the space), the Landa

Xavier Siemens, Ken D. Olum

We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to a new regime where the wavelengths of the opposing wave-trains are very different. We show that in this case the amount

B. Grenier, P. Monod, M. Hagiwara, M. Matsuda

We have performed Electron Spin Resonance measurements on single crystals of the doped spin-Peierls compounds CuGe$_{1-y}$Si$_y$O$_3$ and Cu$_{1-x}$M$_x$GeO$_3$ with M = Zn, Mg, Ni ($x, y\leq 0.1$). The first part of our experiments was performed in the paramagnetic and spin-Peierls phases at 9.5, 95 and 190 GHz. All non-magnetic impurities (Si, Zn and Mg) w

S. James Gates,, Sergei V. Ketov

We propose the 4D, N=1 supergravitational analogues (avatars) of the 4D, N=1 supersymmetric Born-Infeld action in four dimensions for the first time, by using superspace. In particular, a new Born-Infeld type generalization of the Weyl supergravity action is given. A natural new Born-Infeld type generalization of the Einstein supergravity is found as well. W

Walter Hofstetter, Jürgen König, Herbert Schoeller

We study the Fano-Kondo effect in a closed Aharonov-Bohm (AB) interferometer which contains a single-level quantum dot and predict a frequency doubling of the AB oscillations as a signature of Kondo-correlated states. Using Keldysh formalism, Friedel sum rule and Numerical Renormalization Group, we calculate the exact zero-temperature linear conductance $G$

L. Girlanda

We express the two-massless-flavor Gell-Mann--Oakes--Renner ratio in terms of low-energy pi-pi observables, including the O(p^6) double chiral logarithms of generalized chiral perturbation theory. Their contribution is sizeable and tends to compensate the one from the single chiral logarithms. However it is not large enough to spoil the convergence of the ch

B. Z. Kopeliovich, A. Polleri, J. Huefner

We suggest the variation of charmonium suppression with Feynman x_F in heavy ion collisions as a novel and sensitive probe for the properties of the matter created in such reactions. In contrast to the proton-nucleus case where nuclear suppression is weakest at small x_F, final state interactions with the comoving matter create a minimum at x_F=0, which is e

V. Cirigliano, G. Ecker, H. Neufeld

We calculate the leading isospin-violating and electromagnetic corrections for the decay tau -> pi^0 pi nu_tau at low energies. The corrections are small but relevant for the inclusion of tau decay data in the determination of hadronic vacuum polarization especially for the anomalous magnetic moment of the muon. We show that part of the systematic difference

A. I. Iliev

In this paper we develop a new method which is a generalization of the Obreshkoff -Ehrlich method for the cases of algebraic, trigonometric and exponential polynomials. This method has a cubic rate of convergence. It is efficient from the computational point of view and can be used for simultaneous finding all roots if the roots have known multiplicities. Th

A. Iliev, Khr. Semerdzhiev

New modifications of the methods for simultaneous extraction of all roots of polynomials over an arbitrary Chebyshev system are elaborated. A cubic convergence of iterations is proved. The method presented is a generalisation of the classical methods of Obreshkoff and Ehrlich for simultaneous seeking of all roots of algebraic equations. Numerical examples ar

Joerg Rottler, Mark O. Robbins

Shear yielding of glassy polymers is usually described in terms of the pressure-dependent Tresca or von Mises yield criteria. We test these criteria against molecular dynamics simulations of deformation in amorphous polymer glasses under triaxial loading conditions that are difficult to realize in experiments. Difficulties and ambiguities in extending severa

Ntina Savvidou

We show that representations of the group of spacetime diffeomorphism and the Dirac algebra both arise in a phase-space histories version of canonical general relativity. This is the general-relativistic analogue of the novel time structure introduced previously in history theory: namely, the existence in non-relativistic physics of two types of time transla

N. Armesto, C. Pajares, D. Sousa

First results from RHIC on charged multiplicities, evolution of multiplicities with centrality, particle ratios and transverse momentum distributions in central and minimum bias collisions, are analyzed in a string model which includes hard collisions, collectivity in the initial state considered as string fusion, and rescattering of the produced secondaries

M. Suzuki, M. A. Tanatar, Z. Q. Mao, Y. Maeno

The thermal conductivity of Sr2RuO4 along the least conducting direction perpendicular to the RuO2 plane has been studied down to 0.3 K. In this configuration the phonons remain the dominant heat carriers down to the lowest temperature, and their conductivity in the normal state is determined by the scattering on conduction electrons. We show that the phonon

A. K. Rajagopal, R. W. Rendell

Entanglement properties of a basic set of eight entangled three particle pure states possessing certain permutation symmetries are studied. They fall into four sets of two entangled states, differing in their patterns of robustness to entanglement when one of the states is lost. These features are related to the permutation symmetries of the spin states of t

P. Baseilhac, M. Stanishkov

The exact vacuum expectation values of the second level descendent fields $<(\partialϕ)^2({\overline\partial}ϕ)^2e^{aϕ}>$ in the Bullough-Dodd model are calculated. By performing quantum group restrictions, we obtain $<L_{-2}{\overline L}_{-2}Φ_{lk}>$ in the $Φ_{12}$, $Φ_{21}$ and $Φ_{15}$ perturbed minimal CFTs. In particular, the exact expectation value $<

M. Rodriguez, G. -S. Paraoanu, P. Torma

We consider a superfluid of trapped fermionic atoms and study the single vortex solution in the Ginzburg-Landau regime. We define simple analytical estimates for the main characteristics of the system, such as the vortex core size, temperature regimes for the existence of a vortex, and the effects of rotation and interactions with normal fermions. The parame

A. F. Lisetskiy, A. Gelberg, R. V. Jolos, N. Pietralla

The M1 transitions between low-lying T=1 and T=0 states in deformed odd-odd N=Z nuclei are analyzed in the frames of the rotor-plus-particle model. Using the representation of an explicit coupling of angular momenta we show that strong coupling of the quasideuteron configurations to the axially deformed core results in a distribution of the total 0+ --> 1+ s

Hesheng Chen, Linkai Ding, Jingtang He, Haohuai Kuang

We discuss the prospects of a very long baseline neutrino oscillation experiment from HIPA to Beijing. The current understanding of neutrino oscillations, both theoretically and experimentally, are summarized. The figure of merits for interested physics measurements are defined and compared at different distances: 300 km, 700 km, 2100 km and 3000 km. We conc

E. Paal

The essential parts of the operad algebra are concisely presented, which should be useful when confronting with the operadic physics. It is also clarified how the Gerstenhaber algebras can be associated with the linear pre-operads (comp algebras). Their relation to mechanics is concisely discussed. A hypothesis that the Feynman diagrams are observables is pr

Eli Ben-Haïm, Annick Lesne, Jean-Marc Victor

This paper focuses on mechanical aspects of chromatin biological functioning. Within a basic geometric modeling of the chromatin assembly, we give for the first time the complete set of elastic constants (twist and bend persistence lengths, stretch modulus and twist-stretch coupling constant) of the so-called 30-nm chromatin fiber, in terms of DNA elastic pr

Rafael Gallego, Daniel Walgraef, Maxi San Miguel, Raul Toral

The effect of a temporal modulation at three times the critical frequency on a Hopf bifurcation is studied in the framework of amplitude equations. We consider a complex Ginzburg-Landau equation with an extra quadratic term, resulting from the strong coupling between the external field and the unstable modes. We show that, by increasing the intensity of the

Harald Grosse, Yi Liao

We show that a simple and reasonable generalization of the anomalous interaction between the neutral pion and two photons can induce the C-violating three photon decay of the neutral pion in noncommutative quantum electrodynamics. We find that it is mandatory for consistency reasons to include simultaneously the normal neutral pion and photon interaction in

Y. Sumino

When the cancellation of the leading renormalon contributions is incorporated, the total energy of a b bbar system, E_{tot,bbbar}(r) = 2 m_{pole,b} + V_QCD(r), agrees well with the potentials used in phenomenological models for heavy quarkonia in the range 0.5 GeV^-1 < r < 3 GeV^-1. We provide a connection between the conventional potential-model approaches

N. D. Lambert, I. Sachs

We reconstruct the tachyon effective action for unstable D-branes in superstring theory by examining its behaviour near exactly marginal deformations, where the ambigous higher derivative terms can be eliminated. We then compare this action with that obtained in boundary string field theory and find remarkable agreement. In particular, the tension for lower

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

In the energy range of RHIC and LHC the mechanisms of nuclear suppression of charmonia are expected to be strikingly different from what is known for the energy of the SPS. One cannot think any more of charmonium produced on a bound nucleon which then attenuates as it passes through the rest of the nucleus. The coherence length of charmonium production subst

Tudor D. Stanescu, Philip Phillips

We report on a non-perturbative approach to the 1D and 2D Hubbard models that is capable of recovering both strong and weak-coupling limits. We first show that even when the on-site Coulomb repulsion, U, is much smaller than the bandwith, the Mott-Hubbard gap never closes at half-filling in both 1D and 2D. Consequently, the Hubbard model at half-filling is a

L. Shi, P. Danielewicz, R. Lacey

The interplay between spectator and participant matter in heavy-ion collisions is investigated in the context of a microscopic transport model. Transport simulations show that flow patterns for the participant matter are strongly influenced by the presence of the nearby spectator matter. However, the influence is mutual. During the explosion of the participa

Michael Graesser, Scott Thomas

Supersymmetric contributions to all leptonic electromagnetic dipole operators have essentially identical diagramatic structure. With approximate slepton universality this allows the muon anomalous magnetic moment to be related to the electron electric dipole moment in terms of supersymmetric phases, and to radiative flavor changing lepton decays in terms of

Tomohide Terasoma

In this paper, we construct an object of the abelian category of mixed Tate motive associated to multiple zeta values. as a consequence, we prove the inequality of the dimension of the vector space generated by multiple zeta values, which is conjectured by Zagier. (Some errors was corrected from the first version. Namely, we changed the definition of the bou

P. Meszaros, M. J. Rees

In the collapsar scenario, gamma ray bursts are caused by relativistic jets expelled along the rotation axis of a collapsing stellar core. We discuss how the structure and time-dependence of such jets depends on the stellar envelope and central engine properties, assuming a steady jet injection. It takes a few seconds for the jet to bore its way through the