May 2003 arXiv papers — page 16

W. Ethan Duckworth

Let $G$ be a linear algebraic group defined over an algebraically closed field. The double coset question addressed in this paper is the following: Given closed subgroups $X$ and $P$, is the double coset collection $X\backslash G/P$ finite or infinite? We limit ourselves to the case where $X$ is maximal rank and reductive and $P$ parabolic. This paper presen

Jakob Stix

The geometric condition of T. Saito for trivial action of the wild monodromy of a smooth proper curve over the generic point of a trait is transformed to the condition of logarithmic smooth reduction. The proof emphasizes methods and results from logarithmic geometry. It applies to quasi-projective smooth curves with etale boundary divisor.

Amnon Besser

This is the same version that was previously only on my home page. We give a description of geometric realization which makes it evident that it commutes with products. A similar approach is used to treat cyclic sets. Our approach is similar to those of Drinfeld and Grayson.

S. Kitaev, T. Mansour

In this paper we study the number $M_{m,n}$ of ways to place nonattacking pawns on an $m\times n$ chessboard. We find an upper bound for $M_{m,n}$ and analyse its asymptotic behavior. It turns out that $\lim_{m,n\to\infty}(M_{m,n})^{1/mn}$ exists and is bounded from above by $(1+\sqrt{5})/2$. Also, we consider a lower bound for $M_{m,n}$ by reducing this pro

Igor Rivin

We write down a one-dimensional integral formula and compute large-n asymptotics for the expectation of the absolute value of the smallest component of a unit vector in n-dimensional Euclidean space. The method is general, and allows to write the mean over the sphere of an homogeneous function in terms of an expectation of a function of independent, identica

Doron Gepner

The probability of finding a prime multiplet, i.e., a sequence of primes $p$ and $p+a_i$, $i=1... m$, being all primes where $p$ is some prime less than the integer $n$ is naively $1/log(n)^{m+1}$. It is shown that, in reality, it is proportional to this probability by a constant factor which depends on $a_i$ and $m$ but not on $n$, for large $n$. These cons

Matthieu Romagny

In this article we study the modular properties of a family of cyclic coverings of P^1 of degree N, in all odd characteristics. We compute the moduli space of the corresponding algebraic stack over Z[1/2], as well as the Picard groups over algebraically closed fields. We put special emphasis on the study of the fibre of the stack at a prime of wild ramificat

Noriyuki Oshimo

A grand unified model based on SO(10) and supersymmetry is presented to account for the masses and mixing of the neutrinos observed in experiments.

E. Iltan

We study the radiative h^0 (A^0)\to γγdecays in the framework of the general two Higgs doublet model, the so-called model III. We estimate the decay width of the processes at the order of magnitude of 10^{-2} GeV for the intermediate values of the Yukawa couplings. We observe that the analysis of the two photon system provide a comprehensive information for

P. Bicudo, G. Marques

Spontaneous chiral symmetry breaking is accepted to occur in low energy hadronic physics, resulting in the several successful theorems of PCAC. On the other hand scalar confinement is suggested both by the spectroscopy of hadrons and by the string picture of confinement. However these two evidences are apparently conflicting, because chiral symmetry breaking

Carola F. Berger

In calculations of (semi-) inclusive events within perturbative Quantum Chromodynamics, large logarithmic corrections arise from certain kinematic regions of interest which need to be resummed. When resumming soft gluon effects one encounters quantities built out of eikonal or Wilson lines (path ordered exponentials). In this thesis we develop a simplified m

J. Lago, P. D. Battle, M. J. Rosseinsky, A. I. Coldea

Magnetotransport properties of the compound Ca4Mn3O10 are interpreted in terms of activated hopping of small magnetic polarons in the non-adiabatic regime. Polarons are most likely formed around Mn3+ sites created by oxygen substoichiometry. The application of an external field reduces the size of the magnetic contribution to the hopping barrier and thus pro

Joerg Schmalian, Peter G. Wolynes, Sangwook Wu

We argue that the recent Monte Carlo calculations by Geissler and Reichman (cond-mat/0304254) are not conclusive in ruling out or supporting the self-generated glass transition of the Brazovskii model proposed by us.

Iliya V. Karlin, Larisa L. Tatarinova, Alexander N. Gorban, Hans Christian Ottinger

A recently introduced systematic approach to derivations of the macroscopic dynamics from the underlying microscopic equations of motions in the short-memory approximation [Gorban et al, Phys. Rev. E, 63, 066124 (2001)] is presented in detail. The essence of this method is a consistent implementation of Ehrenfest's idea of coarse-graining, realized via a

J. Isidorsson, I. A. M. E. Giebels, H. Arwin, R. Griessen

The dielectric properties of alpha-MgH2 are investigated in the photon energy range between 1 and 6.5 eV. For this purpose, a novel sample configuration and experimental setup are developed that allow both optical transmission and ellipsometric measurements of a transparent thin film in equilibrium with hydrogen. We show that alpha-MgH2 is a transparent, col

Rene' Carmona, Dario Villani

We price weather-contingent options by use of Monte Carlo simulations. After calibrating the models to fit quoted prices, we analyze bid-ask spreads in terms of correlations across markets. Results are presented for a double-trigger Weather vs. Natural Gas call option.

M. D. Lee, S. A. Morgan, K. Burnett

We investigate the properties of the one-dimensional Bose gas at zero temperature, for which exact results exist for some model systems. We treat the interactions between particles in the gas with an approximate form of the many-body T-matrix, and find a form of Gross-Pitaevskii equation valid in 1D. The results presented agree with the exact models in both

Keshav N. Shrivastava

The usual cyclotron resonance occurs at ω_c=eB/m*c which is independent of spin. The new resonances depend on spin. The new resonances occur at ω_{c\pm}=(1/2)g_{\pm}eB/m*c where (1/2)g_{\pm}= {\it l}+(1/2)\pm s/(2{\it l}+1). The energy in the centre of two new frequencies varies as the square root of the 2-dimensional electrons due to spin excess in the Gaus

Jian Qi Shen

Wave propagation inside generalized gyrotropic media is considered in the present Letter. It is shown that in this type of materials, the left- and right- handed circularly polarized light can be coupled to each other, which may possess some potential applications to quantum information.

D. J. Priour, E. H. Hwang, S. Das Sarma

We develop a lattice mean field theory for ferromagnetic ordering in diluted magnetic semiconductors by taking into account the spatial fluctuations associated with random disorder in the magnetic impurity locations and the finite mean free path associated with low carrier mobilities. Assuming a carrier-mediated indirect RKKY exchange interaction among the m

Ya. V. Fominov, A. A. Golubov, M. Yu. Kupriyanov

We study the Josephson junction between two d-wave superconductors, which is discussed as an implementation of a qubit. We propose an approach that allows to calculate the decoherence time due to an intrinsic dissipative process: quantum tunneling between the two minima of the double-well potential excites nodal quasiparticles which lead to incoherent dampin

Romi Mankin, Astrid Haljas, Risto Tammelo, Dmitri Martila

The noise-flatness-induced hypersensitive transport of overdamped Brownian particles in a tilted ratchet system driven by multiplicative nonequilibrium three-level Markovian noise and additive white noise is considered. At low temperatures the enhancement of current is very sensitive to the applied small static tilting force. It is established that the enhan

D. Branch, P. Garnavich, T. Matheson, E. Baron

We present 29 optical spectra of the normal Type Ia SN 1998aq, ranging from 9 days before to 241 days after the time of maximum brightness. This spectroscopic data set, together with photometric data presented elsewhere, makes SN 1998aq one of the best observed Type Ia supernova at optical wavelengths. We use the parameterized supernova synthetic-spectrum co

Zheng Xiaoping, Liu Xuewen, Kang Miao, Yang Shuhua

We study the bulk viscosity of strange quark matter(SQM) in density dependent quark mass model(DDQM) under the background of self-consistent thermodynamics. The correct formulae, with which the viscosity can be evaluated, are derived. We also find that the viscosity in DDQM can be higher by 2 to 3 orders of magnitude than MIT bag model. We calculate the damp

Abraham Loeb

Gravitationally redshifted absorption lines of Fe XXVI, Fe XXV, and O VIII were inferred recently in the X-ray spectrum of the bursting neutron star EXO 0748-676. We place an upper limit on the stellar magnetic field based on the iron lines. The oxygen absorption feature shows a multiple component profile that is consistent with Zeeman splitting in a magneti

Rene A. Ong

This paper summarizes the status of very high-energy (VHE) astronomy, as of early 2003. It concentrates on observations made by gamma-ray telescopes operating at energies above 10 GeV. This field is an exciting one to be working in, with a growing and varied list of established sources that includes plerions, supernova remnants, and active galactic nuclei. N

Zhi-zhong Xing

We stress that massive neutrinos may be Majorana particles even if the effective mass of the neutrinoless double beta decay m_ee vanishes. We show that current neutrino oscillation data do allow m_ee = 0 to hold, if the Majorana CP-violating phases lie in two specific regions. Strong constraints on three neutrino masses can then be obtained. We find that the

Marco Cariglia

In spacetimes admitting Yano tensors the classical theory of the spinning particle possesses enhanced worldline supersymmetry. Quantum mechanically generators of extra supersymmetries correspond to operators that in the classical limit commute with the Dirac operator and generate conserved quantities. We show that the result is preserved in the full quantum

Mboyo Esole, Filipe Freire

BRST cohomology methods are used to explain the origin of the SL(2,R) symmetry in Yang-Mills theories. Clear evidence is provided for the unphysical nature of this symmetry. This is obtained from the analysis of a local functional of mass dimension two and constitutes a no-go statement for giving a physical meaning to condensates associated with the symmetry

Luca Sommovigo

We study the Penrose limit of a supersymmetric IIB background, with non-trivial NS 3-form field strength, obtaining a solution with the smallest number of supercharges (i.e. 16) allowed; we write down explicitly the superalgebra of the theory, build the supersymmetric associated IIB string sigma model and make conjectures on the dual gauge theory.

S. Courty, B. Dollet, F. Elias, P. Heinig

We deform a two-dimensional (2D) foam, created in a Langmuir monolayer, by applying a mechanical perturbation, and simultaneously image it by Brewster angle microscopy. We determine the foam stress tensor (through a determination of the 2D gas-liquid line tension, 2.35 $\pm$ 0.4 pJ$\cdot$m$^{-1}$) and the statistical strain tensor, by analyzing the images of

Jose Mendez Gamboa, Antonio O. Bouzas

We study the quantization of many-body systems in two dimensions in rotating coordinate frames using a gauge invariant formulation of the dynamics. We consider reference frames defined by linear and quadratic gauge conditions. In both cases we discuss their Gribov ambiguities and commutator algebra. We construct the momentum operators, inner-product and Hami

T. Kengatharam, S. Twareque Ali

A general scheme is proposed for constructing vector coherent states, in analogy with the well-known canonical coherent states, and their deformed versions, when these latter are expressed as infinite series in powers of a complex variable $z$. In the present scheme, the variable $z$ is replaced by a matrix valued function over appropriate domains. As partic

Tatsuya Tate, Steve Zelditch

We give asymptotic formulas for the multiplicities of weights and irreducible summands in high-tensor powers $V_λ^{\otimes N}$ of an irreducible representation $V_λ$ of a compact connected Lie group $G$. The weights are allowed to depend on $N$, and we obtain several regimes of pointwise asymptotics, ranging from a central limit region to a large deviations

Jack Morava

We study the Madsen-Tillmann spectrum $\C P^\infty_{-1}$ as a quotient of the Mahowald pro-object $\C P^{\infty}_{-\infty}$, which is closely related to the Tate cohomology of circle actions. That theory has an associated symplectic structure, whose symmetries define the Virasoro operations on the cohomology of moduli space constructed by Kontsevich and Witt

Bhupinder Singh Anand

In a forthcoming book, professional computer scientist and physicist Paul Budnik presents an exposition of classical mathematical theory as the backdrop to an elegant thesis: we can interpret any model of a formal system of Peano Arithmetic in an appropriate, digital, computational language. In this paper we attempt - without addressing the question of wheth

Alexei Grigoriev

We give a uniform asymptotic bound for the number of zeros of complete Abelian integrals in domains bounded away from infinity and the singularities.

Bhupinder Singh Anand

We present some arguments for the thesis that a set-theoretic inspired faith, in the ability of intuitive truth to faithfully reflect relationships between elements of a Platonic universe, may be as misplaced as an assumption that such truth cannot be expressed in a constructive, and effectively verifiable, manner.

Bhupinder Singh Anand

If we define classical foundational concepts constructively, and introduce non-algorithmic effective methods into classical mathematics, then we can bridge the chasm between truth and provability, and define computational methods that are not Turing-computable.

Bhupinder Singh Anand

Whatever other beliefs there may remain for considering Cantor's diagonal argument as mathematically legitimate, there are three that, prima facie, lend it an illusory legitimacy; they need to be explicitly discounted appropriately. The first, Cantor's diagonal argument defines a non-countable Dedekind real number; the second, Goedel uses the argumen

Bhupinder Singh Anand

We formally define a "mathematical object" and "set". We then argue that expressions such as "(Ax)F(x)", and "(Ex)F(x)", in an interpretation M of a formal theory P, may be taken to mean "F(x) is true for all x in M", and "F(x) is true for some x in M", respectively, if, and only if, the predicate letter "F

Bhupinder Singh Anand

We consider a philosophical question that is implicit in Selmer Bringsjord's paper, "The narrational case against Church's Thesis": If, as Mendelson argues, the classically accepted definitions of foundational concepts such as "partial recursive function", "function", "(Tarskian) truth", "set" etc. are vague an

Hidenori Sonoda

We introduce a new prescription for renormalizing Feynman diagrams. The prescription is similar to BPHZ, but it is mass independent, and works in the massless limit as the MS scheme with dimensional regularization. The prescription gives a diagrammatic solution to Wilson's exact renormalization group differential equation.

A. Capella

An introduction to dynamical microscopic models of hadronic and nuclear interactions is presented. Special emphasis is put in the relation between multiparticle production and total cross-section contributions. In heavy ion collisions, some observables, considered as signals of the production of a Quark Gluon Plasma (QGP), are studied. It is shown that they

I. V. Anikin, B. Pire, O. V. Teryaev

We give a theoretical description of the L3 Collaboration data on the cross-section of the exclusive two $ρ$-mesons production in $γγ^*$ collision with large photon virtuality. These data prove the scaling behaviour of the leading twist generalized distribution amplitude of vector mesons. They thus prove the relevance of a partonic description of the exclusi

Mihoko M. Nojiri

In supersymmetric models a gluino can decay into $tb\tildeχ^{\pm}_1$ through a stop or a sbottom. The decay chain produces an edge structure in the $m_{tb}$ distribution. Monte Carlo simulation studies show that the end point and the edge height would be measured at the CERN LHC by using a sideband subtraction technique. The stop and sbottom masses as well a

Mihoko M. Nojiri

A short tour of supersymmetric dark matter and its connection to collider physics.

I. Marfin, V. Mossolov, T. Shishkina

The WW production in gamma-gamma scattering is considered in the Standard Model. The main contribution to radiative effects for the process gamma-gamma->WW has been calculating and analyzing. It is found the latter is considerable at high energies and greatly contributes to the differential cross section $dσ$ at various polarizations of initial photons and f

Stephen L. Olsen

We observe a narrow enhancement near 2m_p in the invariant mass spectrum of p\bar{p} pairs from radiative J/psi-->gamma p\bar{p} decays. No similar structure is seen in J/psi-->pi0 p\bar{p} decays. The results are based on an analysis of a 58 million event sample of J/psi decays accumulated with the BESII detector at the Beijing electron-positron collider. T

John R. Klauder

A sketch of the affine quantum gravity program illustrates a different perspective on several difficult issues of principle: metric positivity; quantum anomalies; and nonrenormalizability.

C. Romero, F. Dahia

We give a brief review of recent developments in five-dimensional theories of spacetime and highlight their geometrical structure mainly in connection with the Campbell-Magaard theorem.

O. Gunnarsson, M. Calandra, J. E. Han

Resistivity saturation is observed in many metallic systems with a large resistivity, i.e., when the resistivity has reached a critical value, its further increase with temperature is substantially reduced. This typically happens when the apparent mean free path is comparable to the interatomic separations - the Ioffe-Regel condition. Recently, several excep

C. A. Cardoso, F. M. Araujo-Moreira, V. P. S. Awana, H. Kishan

Strong evidences of a spin glass phase on polycrystalline RuSr2Ln1.5Ce0.5Cu2O10-x (LnRu-1222, Ln = Y, Ho and Dy) is provided by ac susceptibility and dc magnetization measurements. The fingerprint of a spin glass transition, the frequency-dependent cusp in ac susceptibility vs. T measurements at low magnetic field, is observed for all LnRu-1222 samples. The

A. E. Miroshnichenko, S. Flach, B. Malomed

We study the scattering of solitons in the nonlinear Schroedinger equation on local inhomogeneities which may give rise to resonant transmission and reflection. In both cases, we derive resonance conditions for the soliton's velocity. The analytical predictions are tested numerically in regimes characterized by various time scales. Special attention is p

L. X. You, P. H. Wu

As nature junction geometry of the d-wave cuprate superconductor/insulator/the mixture of s-wave and d-wave cuprate superconductor, the upmost surface junction of intrinsic Josephson junction stack fabricated on Bi$_2$Sr$_2$CaCu$_2$O$_{8+d}$ single crystals was measured and discussed. We successfully observed half-integral microwave induced steps as well as

D. Monnier Ragaigne, W. van Driel, S. E. Schneider, C. Balkowski

A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm HI line using the Nancay telescope. All have a K_s-band mean central surface brightness, measured within a 5 arcsec radius, fainter than 18 mag/arcsec^2 and a K_s-band isophotal radius at the 20 mag/arcsec^2 level larger than 20 a

Thomas M. Brown, Henry C. Ferguson, Ed Smith, Randy A. Kimble

We present a color-magnitude diagram (CMD) for a minor-axis field in the halo of the Andromeda galaxy (M31), 51 arcmin (11 kpc) from the nucleus. These observations, taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope, are the deepest optical images yet obtained, attaining 50% completeness at V = 30.7 mag. The CMD, constructed from

Fumitaka Nakamura, Zhi-Yun Li

We study the non-axisymmetric evolution of magnetized clouds, using a 2D MHD code based on the physically motivated thin-disk approximation. We found that such clouds become unstable to non-axisymmetric perturbations after the supercritical cores are formed due to ambipolar diffusion. We show that for a wide range of initial cloud parameters, the $m=2$ mode

Eduardo L. Martin, David Barrado y Navascues, Isabelle Baraffe, Herve Bouy

We present the results of a high-resolution imaging survey for brown dwarf (BD) binaries in two open clusters. The observations were carried out with WFPC2 onboard HST. Our sample consists of 8 BD candidates in the alpha Per cluster and 25 BD candidates in the Pleiades. We have resolved 4 binaries in the Pleiades with separations in the range 0".094--0&#

T. Sumi, X. Wu, A. Udalski, M. Szymanski

We present a proper motion (μ) catalogue of 5,080,236 stars in 49 Optical Gravitational Lensing Experiment II (OGLE-II) Galactic bulge (GB) fields, covering a range of -11 deg. <l< 11 deg. and -6 deg. <b<3 deg., the total area close to 11 square degrees. The proper motion measurements are based on 138 - 555 I-band images taken during four observing seasons:

I. V. Ponomarev, L. I. Deych, A. A. Lisyansky

We introduce a computationally efficient approach to calculating the characteristics of excitons in quantum wells. In this approach we derive a system of self-consistent equations describing the motion of an electron-hole pair. The motion in the growth direction of the quantum well in this approach is separated from the in-plane motion, but each of them occu

PHENIX Collaboration, S. S. Adler

The anisotropy parameter v_2, the second harmonic of the azimuthal particles distribution, has been measured with the PHENIX detector in Au+Au collisions at sqrt(s_NN) = 200 GeV for identified and inclusive charged particles at central rapidities (|eta| < 0.35) with respect to the reaction plane defined at high rapidities (|eta| = 3-4). The v_2 for all parti

Jason M. Amini, Harvey Gould

The cesium 6S_1/2 scalar dipole polarizability alpha_0 has been determined from the time-of-flight of laser cooled and launched cesium atoms traveling through an electric field. We find alpha_0 = 6.611+-0.009 x 10^-39 C m^2/V= 59.42+-0.08 x 10^-24 cm^3 = 401.0+-0.6 a_0^3. The 0.14% uncertainty is a factor of fourteen improvement over the previous measurement

Hideo Kodama, Akihiro Ishibashi

We show that in four or more spacetime dimensions, the Einstein equations for gravitational perturbations of maximally symmetric vacuum black holes can be reduced to a single 2nd-order wave equation in a two-dimensional static spacetime for a gauge-invariant master variable, irrespective of the mode of perturbations. Our formulation applies to the case of va

S. G. Bhongale, J. N. Milstein, M. J. Holland

We propose increasing the fractional quantum Hall gap of a rapidly rotating Bose gas by increasing the interatomic interactions via a Feshbach resonance. The generation of molecules by the resonance causes pair correlations to grow throughout the system effecting the ground state. By an extension of the usual Chern-Simons theory, built of composite atoms and

Mark Van Raamsdonk

In systems of intersecting branes, we consider sets of directions in which one type of brane is pointlike, with transverse fluctuations described by matrix coordinates X, and the other set of branes is space-filling, with a local symmetry associated to its worldvolume gauge field. Under this symmetry, massless fields associated with p-p' strings should trans

Marcela Carena, Antonio Delgado, Eduardo Ponton, Tim M. P. Tait

Warped extra dimensions allow a novel way of solving the hierarchy problem, with all fundamental mass parameters of the theory naturally of the order of the Planck scale. The observable value of the Higgs vacuum expectation value is red-shifted, due to the localization of the Higgs field in the extra dimension. It has been recently observed that, when the ga

Marek Gazdzicki

The history and the main results of the energy scan program at the CERN SPS are reviewed. Several anomalies in energy dependence of hadron production predicted as signals of deconfinement phase transition are observed and they indicate that the onset of deconfinement is located at about 30 A GeV. For the first time we seem to have clear evidence for the exis

A. S. Kechris, V. G. Pestov, S. Todorcevic

We study in this paper some connections between the Fraisse theory of amalgamation classes and ultrahomogeneous structures, Ramsey theory, and topological dynamics of automorphism groups of countable structures.

Brian M. Andersen

The quantum interference between two nonmagnetic impurities is studied numerically in both the d-wave superconducting (DSC) and the d-density wave (DDW) state. In all calculations we include the tunnelling through excited states from the CuO$_2$ planes to the BiO layer probed by the STM tip. Compared to the single impurity case, a systematic study of the mod

Christian Korff

The spectra of recently constructed auxiliary matrices for the six-vertex model respectively the spin s=1/2 Heisenberg chain at roots of unity q^N=1 are investigated. Two conjectures are formulated both of which are proven for N=3 and are verified numerically for several examples with N>3. The first conjecture identifies an abelian subset of auxiliary matric

A. Vuorinen

The perturbative expansion of the pressure of hot QCD is computed here to order g^6ln(g) in the presence of finite quark chemical potentials. In this process all two- and three-loop one-particle irreducible vacuum diagrams of the theory are evaluated at arbitrary T and mu, and these results are then used to analytically verify the outcome of an old order g^4

S. Bueltmann

The first result of the pp2pp experiment at RHIC on elastic scattering of polarized protons at sqrt{s} = 200 GeV is reported here. The exponential slope parameter b of the diffractive peak of the elastic cross section in the t range 0.010 <= |t| <= 0.019 (GeV/c)^2 was measured to be b = 16.3 +- 1.6 (stat.) +- 0.9 (syst.) (GeV/c)^{-2} .

Kazuo Fujikawa, Peter van Nieuwenhuizen

A fully quantum version of the Witten-Olive analysis of the central charge in the N=1 Wess-Zumino model in $d=2$ with a kink solution is presented by using path integrals in superspace. We regulate the Jacobians with heat kernels in superspace, and obtain all superconformal anomalies as one Jacobian factor. The conserved quantum currents differ from the Noet

A. De Martino, R. Egger, F. Murphy-Armando, K. Hallberg

We review the theoretical description of spin-orbit scattering and electron spin resonance in carbon nanotubes. Particular emphasis is laid on the effects of electron-electron interactions. The spin-orbit coupling is derived, and the resulting ESR spectrum is analyzed both using the effective low-energy field theory and numerical studies of finite-size Hubba

A. S. Denikin, V. I. Zagrebaev

The dynamics and the mechanisms of preequilibrium-light-particle formation in nucleus-nucleus collisions at low and intermediate energies are studied on the basis of a classical four-body model. The angular and energy distributions of light particles from such processes are calculated. It is found that, at energies below 50 MeV per nucleon, the hardest secti

Amit Giveon, Eliezer Rabinovici, Amit Sever

Two dimensional charged black holes in string theory can be obtained as exact (SL(2,R)xU(1))/U(1) quotient CFTs. The geometry of the quotient is induced from that of the group, and in particular includes regions beyond the black hole singularities. Moreover, wavefunctions in such black holes are obtained from gauge invariant vertex operators in the SL(2,R) C

Juan J. Sanz-Cillero, John F. Donoghue, Andreas Ross

We discuss the chiral corrections to f_B and B_B with particular emphasis on determining the portion of the correction that arises from long distance physics. For very small pion and kaon masses all of the usual corrections are truly long distance, while for larger masses the long distance portion decreases. These chiral corrections have been used to extrapo

Chun-Khiang Chua, Wei-Shu Hou, Gwo-Guang Wong

A slow J/psi excess exists in the inclusive B -> J/psi+X spectrum, and is indicative of some hadronic effect. From color octet nature of c cbar pair in b-> c cbar s decay, one such possibility would be B -> J/psi+ K_g decay, where K_g is a hybrid resonance with sbar g q constituents. We show that a K_g resonance of ~ 2 GeV mass and suitably broad width could

S. Groot Nibbelink

In the recent literature one can find calculations of various one--loop amplitudes, like anomalies, tadpoles and vacuum energies, on specific types of orbifolds, like S^1/Z_2. This work aims to give a general description of such one--loop computations for a large class of orbifold models. In order to achieve a high degree of generality, we formulate these ca

A. Koitzsch, S. V. Borisenko, A. A. Kordyuk, T. K. Kim

Angle-resolved photoemission spectroscopy (ARPES) is used to study the doping dependence of the lifetime and the mass renormalization of the low energy excitations in the high-Tc cuprate (Bi,Pb)_2Sr_2CaCu_2O_8 along the zone diagonal. We find a linear energy de-pendence of the scattering rate for the underdoped samples and a quadratic energy depend-ence in t

S. Recksiegel, Y. Sumino

We extend the formalism based on perturbative QCD that was developed in our previous work, and compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. All the corrections up to O(alpha_s^5 m) are included in the computations. We find agreement (with respect to theoretical uncertain

S. Ettori

The recent constraints on the cosmological parameters put from the observations of the WMAP satellite limit the cosmic baryon fraction in a range that is larger than, and marginally consistent with, what is measured in galaxy clusters. This rises the question whether or not we are considering all the ingredients of cluster baryonic budget. Making a careful w

Ilka Agricola, Thomas Friedrich

For any triple $(M^n, g, \nabla)$ consisting of a Riemannian manifold and a metric connection with skew-symmetric torsion we introduce an elliptic, second order operator $Ω$ acting on spinor fields. In case of a reductive space and its canonical connection our construction yields the Casimir operator of the isometry group. Several non-homogeneous geometries

F. Rao, A. Crisanti, F. Ritort

We have computed the time-dependent susceptibility for the finite-size mean-field Random Orthogonal model (ROM). We find that for temperatures above the mode-coupling temperature the imaginary part of the susceptibility $χ&#39;&#39;(ν)$ obeys the scaling forms proposed for glass-forming liquids. Furthermore, as the temperature is lowered the peak frequency o

Anton Kapustin, Yi Li

We compute topological correlators in Landau-Ginzburg models on a Riemann surface with arbitrary number of handles and boundaries. The boundaries may correspond to arbitrary topological D-branes of type B. We also allow arbitrary operator insertions on the boundary and in the bulk. The answer is given by an explicit formula which can be regarded as an open-s

Kazuo Hida

The mixture of bond-alternating and uniform S=1/2 antiferromagnetic Heisenberg chains is investigated by the density matrix renormalization group method. The ground state magnetization curve is calculated and the exchange parameters are determined by fitting to the experimentally measured magnetization curve of \CuCl$_{2x}$Br$_{2(1-x)}$($γ$-pic)$_2$. The low

G. F. R. Ellis, U. Kirchner, W. R. Stoeger

The idea of a multiverse -- an ensemble of universes -- has received increasing attention in cosmology, both as the outcome of the originating process that generated our own universe, and as an explanation for why our universe appears to be fine-tuned for life and consciousness. Here we carefully consider how multiverses should be defined, stressing the dist

Philip Phillips, Denis Dalidovich

We analyze here the consequence of local rotational-symmetry breaking in the quantum spin (or phase) glass state of the quantum random rotor model. By coupling the spin glass order parameter directly to a vector potential, we are able to compute whether the system is resilient (that is, possesses a phase stiffness) to a uniform rotation in the presence of ra

W. Wang, Y. Zhao

We show the spectral properties of 15 spin-powered X-ray pulsars, and the correlation between the average power-law photon index and spin-down rate. Generation order parameters (GOPs) based on polar-cap models are introduced to characterize the X-ray pulsars. We calculate three definitions of generation order parameters due to the different effects of magnet

I. S. Tupitsyn, P. C. E. Stamp, N. V. Prokof&#39;ev

The nuclear spin-mediated quantum relaxation of ensembles of tunneling magnetic molecules causes a &#39;hole&#39; to appear in the distribution of internal fields in the system. The form of this hole, and its time evolution, are studied using Monte Carlo simulations. It is shown that the line-shape of the tunneling hole in a weakly polarised sample must have

A. Sher, R. Appel, G. S. Atoyan, B. Bassalleck

E865 at the Brookhaven National Laboratory AGS collected about 70,000 K+(e3) events with the purpose of measuring the relative K+(e3) branching ratio. The pi0 in all the decays was detected using the e+e- pair from pi0 -> e+e-gamma decay and no photons were required. Using the Particle Data Group branching ratios for the normalization decays we obtain BR(K+(

Christopher E. Kuklewicz, Marco Fiorentino, Gaétan Messin, Franco N. C. Wong

We have demonstrated a high-flux source of polarization-entangled photons using a type-II phase-matched periodically-poled KTP parametric downconverter in a collinearly propagating configuration. We have observed quantum interference between the single-beam downconverted photons with a visibility of 99% and a measured coincidence flux of 300/s/mW of pump. Th

B. Zeng, D. L. Zhou, P. Zhang, Z. Xu

We revisit the criterion of multi-particle entanglement based on the overlaps of a given quantum state $ρ$ with maximally entangled states. For a system of $m$ particles, each with $N$ distinct states, we prove that $ρ$ is $m$-particle negative partial transpose (NPT) entangled, if there exists a maximally entangled state $|{\rm MES}>$, such that $<{\rm MES}

Pawel Wocjan, Dominik Janzing, Thomas Beth

QMA and QCMA are possible quantum analogues of the complexity class NP. In QCMA the verifier is a quantum program and the proof is classical. In contrast, in QMA the proof is also a quantum state. We show that two known QMA-complete problems can be modified to QCMA-complete problems in a natural way: (1) Deciding whether a 3-local Hamiltonian has low energy

N. David Mermin

To celebrate the 60th birthday of Charles H.Bennett I (1) publicly announce my referee reports for the original dense coding and teleportation papers, (2) present a very economical solution to the Bernstein-Vazirani problem that does not even hint at interference between multiple universes, and (3) describe how I inadvertently reinvented the Copenhagen inter

N. Kolachevsky, M. Fischer, S. G. Karshenboim, T. W. Haensch

We have applied an optical method to the measurement of the 2S hyperfine interval in atomic hydrogen. The interval has been measured by means of two-photon spectroscopy of the 1S-2S transition on a hydrogen atomic beam shielded from external magnetic fields. The measured value of the 2S hyperfine interval is equal to 177 556 860(15) Hz and represents the mos

Mikhail B. Bogdanov, Alexandr V. Fedorenko

We present results of the digital spectral analysis of the time series containing the daily samples of the atmosphere surface pressure measured at Saratov city from Jan 1, 1995 to Dec 31, 1999. We calculated also cross correlation functions between the pressure fluctuations and the planetary geomagnetic indices, Ap and Cp, and cross correlation function betw

A. Stellberger, K. Meier, O. Niedermaier, O. Nix

In 1998, the detector H1 at HERA has been equipped with a small backward spectrometer, the Very Low Q^2 (VLQ) spectrometer comprising a silicon tracker, a tungsten - scintillator sandwich calorimeter, and a Time-of-Flight system. The spectrometer was designed to measure electrons scattered under very low angles, equivalent to very low squared four - momentum

R. Sobie

A Grid testbed has been established using resources at 12 sites across Canada involving researchers from particle physics as well as other fields of science. We describe our use of the testbed with the BaBar Monte Carlo production and the ATLAS data challenge software. In each case the remote sites have no application-specific software stored locally and ins