December 2001 arXiv papers — page 6

R. Flume, R. Poghossian, H. Storch

The n-instanton contribution to the Seiberg-Witten prepotential of N=2 supersymmetric d=4 Yang Mills theory is represented as the integral of the exponential of an equivariantly exact form. Integrating out an overall scale and a U(1) angle the integral is rewritten as (4n-3) fold product of a closed two form. This two form is, formally, a representative of t

Paul Koerber, Alexander Sevrin

We review a method to find the non-abelian open superstring effective action, thereby settling the issue of the ordering ambiguities. We start from solutions to Yang-Mills which, in D-brane context, define certain BPS configurations. Studying their deformations in the abelian case shows that the Born-Infeld action is the unique deformation which admits solut

Heinrich Saller

Stable states (particles), ghosts and unstables states (particles) are discussed with respect to the time representations involved, their unitary groups and the induced Hilbert spaces. Unstable particles with their decay channels are treated as higher dimensional probability collectives with nonabelian probability groups U(n) generalizing the individual abel

Igor A. Bandos, Jose A. de Azcarraga, Jose M. Izquierdo

We study the coupling of supergravity with a purely bosonic brane source (bosonic p-brane). The interaction, described by the sum of their respective actions, is self-consistent if the bosonic p-brane is the pure bosonic limit of a super-p-brane. In that case the dynamical system preserves 1/2 of the local supersymmetry characteristic of the `free' super

A. A. Zheltukhin, U. Lindström

A new class of twistor-like string models in four-dimensional space-time extended by the addition of six tensorial central charge (TCC) coordinates $z_{mn}$ is studied. The Hamiltonian of tensionless string in the extended space-time is derived and its symmetries are investigated. We establish that the string constraints reduce the number of independent TCC

Hiroyuki Fuji

The string theory on symmetric product describes the second-quantized string theory. The development for the bosonic open string was discussed in the previous work. In this paper, we consider the open superstring theory on the symmetric product and examine the nature of the second quantization. The fermionic partition functions are obtained from the consiste

Stanley J. Brodsky

The light-front representation of quantum chromodynamics provides a frame-independent, quantum-mechanical representation of hadrons at the amplitude level, capable of encoding their multi-quark, hidden-color and gluon momentum, helicity, and flavor correlations in the form of universal process-independent hadron wavefunctions. The universality and frame-inde

Fredrick Olness

Reliable knowledge of parton distribution functions is crucial for many searches for new physics signals in the next generation of experiments. Presently, there remain a number of open questions regarding the PDF's and their uncertainties. We briefly discuss these issues, and consider aspects where a future high-precision fixed-target experiment might co

S. Kretzer, D. Mason, F. Olness

Charged current DIS charm production measures the strange-quark PDF. A complete analysis requires both a fully differential theoretical calculation, and a Monte Carlo detector simulation. We present analytic and numeric results at NLO suitable for experimental analysis.

D. Becirevic, M. Ciuchini, E. Franco, V. Gimenez

We present a next-to-leading order determination of the gluino-mediated SUSY contributions to B_d-Bbar_d mixing and to the CP asymmetry a_{J/psi K_s} in the framework of the mass-insertion approximation. Using hadronic matrix elements recently computed on the lattice, we obtain improved constraints on the squark-mass splittings.

R. B. Nevzorov, M. A. Trusov

In the strong Yukawa coupling limit the renormalization of trilinear couplings $A_i(t)$ and combinations of the scalar particle masses $\mathfrak{M}_i^2(t)$ are studied in the framework of the Next--to--Minimal SUSY Model. The dependence of given parameters on their initial values at the Grand Unification scale disappears when the solutions of the renormaliz

Antonio Dobado, Silvia N. Santalla

By using Chiral Perturbation Theory and the Uehling-Uhlenbeck equation we compute the viscosity of a pion gas, in the low temperature and low density regime, in terms of the temperature, and the pion fugacity. The viscosity turns out to be proportional to the squared root of the temperature over the pion mass. Next to leading corrections are proportional to

Z. Fodor

The clustering of ultra high energy (above 5\cdot 10^{19} eV) cosmic rays (UHECR) suggests that they might be emitted by compact sources. We present a statistical analysis on the source density based on the multiplicities. The propagation of UHECR protons is studied in detail. The UHECR spectrum is consistent with the decay of GUT scale particles and/or with

A. Bueno, M. Campanelli, S. Navas-Concha, A. Rubbia

In this paper we discuss the detection of CP and T-violation effects in the framework of a neutrino factory. We introduce three quantities, which are good discriminants for a non vanishing complex phase ($δ$) in the $3\times 3$ neutrino mixing matrix. We find that these three discriminants (in vacuum) all scale with $L/E_ν$. Matter effects modify the scaling

Maciej A. Nowak

I explain the concept that light quarks diffuse in the QCD vacuum following the spontaneous breakdown of chiral symmetry. I exploit the striking analogy to disordered electrons in metals, identifying, among others, the universal regime described by random matrix theory, diffusive regime described by chiral perturbation theory and the crossover between these

A. Höcker, H. Lacker, S. Laplace, F. Le Diberder

An analysis of the CKM matrix parameters within the {\it R}fit approach is presented using updated input values with special emphasis on the recent $\sin{2β}$ measurements from BABAR and Belle. The QCD Factorisation Approach describing $B \to ππ,Kπ$ decays has been implemented in the software package CKMfitter. Fits using branching ratios and CP asymmetries

J. Gasser, A. Rusetsky, J. Schacher

These are the proceedings of the workshop "HadAtom01", held at the Institut fuer Theoretische Physik, Universitaet Bern, October 11 - 12, 2001. The main topics discussed at the workshop were the physics of hadronic atoms and in this context recent results in experiment and theory. Included here are the list of participants, the scientific program and

Hisao Nakkagawa, Hiroshi Yokota, Koji Yoshida, Yuko Fueki

Chiral phase transition in thermal QCD is studied by using the Dyson-Schwinger (DS) equation in the real time hard thermal loop approximation. Our results on the critical temperature and the critical coupling are significantly different from those in the preceding analyses in the ladder DS equation, showing the importance of properly taking into account the

Itzhak Tserruya

Selected topics in the field of relativistic heavy-ion collisions are reviewed f rom the 15 year research programme at the SPS at CERN and the AGS at BNL, and from the first run of the Relativistic Heavy-Ion Collider at BNL.

Teruyuki Kitabayashi, Masaki Yasue

The Zee model, which employs the standard Higgs scalar ($ϕ$) with its duplicate ($ϕ^\prime$) and a singly charged scalar ($h^+$), can utilize two global symmetries associated with the conservation of the numbers of $ϕ$ and $ϕ^\prime$, $N_{ϕ,ϕ^\prime}$, where $N_ϕ+N_{ϕ^\prime}$ coincides with the hypercharge while $N_ϕ-N_{ϕ^\prime}$ ($\equiv X$) is a new cons

Timothy L. Barklow

The study of strong symmetry breaking at an e+e linear collider with sqrt(s)=0.5-1.5 TeV is reviewed. It is shown that processes such as e+e- --> nu nubar W+ W-, e+e- --> nu nubar t tbar, and and e+e- --> W+ W- can be used to measure chiral Lagrangian and strong resonance parameters. The linear collider results are compared with those expected from the LHC.

Pedro Pacheco de Queiroz Filho, Jorge Eduardo Cieza Montalvo

We investigate the production, signatures and backgrounds of a pair of heavy-exotic charged leptons and a heavy-exotic neutrino together with the exotic charged lepton in the framework of the vector singlet model, vector doublet model, and fermion-mirror-fermion model, at the CERN Large Hadron Collider (LHC). We still show that the cross-sections for the cas

I. Montvay, S. Hands, L. Scorzato, J. I. Skullerud

The DESY-Swansea Collaboration performed numerical simulations investigating SU(2) lattice gauge theory at non-zero chemical potential with one staggered quark flavour in the adjoint representation. This lattice model has similar features to QCD itself and its study gives interesting insights into some open problems of high density quark matter. In particula

David Urner

The determination of CKM matrix elements in the b-sector is discussed, emphasizing the new measurements of Vub and Vcb by the CLEO collaboration.

P. N. Burrows

I summarise the QCD programme at the high-energy linear e+e- collider, as reported in the TESLA TDR and Linear Collider Physics Resource Book.

P. N. Burrows

I summarise the status of the LCFI Collaboration R&D programme for a CCD-based vertex detector for the linear collider.

Paul Newman

Recent measurements of the diffractive cross section in deep-inelastic scattering at HERA are presented. The data are used to investigate the factorisation properties of diffractive DIS and to examine its quantum chromodynamic structure. Models based on the colour dipole approach to DIS are also tested.

Siegfried Bethke

Studies of hadronic final states of $e^+e^-$ annihilations, observed at the Large Electron Positron Collider LEP at CERN, are reviewed. The topics included cover measurements of $α_s$, hadronic event shapes and hadronisation studies, tests of asymptotic freedom and of the non-Abelian gauge structure of QCD, differences between quark and gluon jets, tests of

2 collaboration

The cross section of the process e+e- -> pi+pi- has been measured using about 114000 events collected by the CMD-2 detector at the VEPP-2M e+e- collider in the center-of-mass energy range from 0.61 to 0.96 GeV. Results of the pion form factor determination with a 0.6% systematic uncertainty are presented. Implications for the hadronic contribution to the muo

ZEUS Collaboration

Dijet differential cross sections for the reaction e+p -> e+ + jet + jet + X in the photoproduction regime have been measured with the ZEUS detector at HERA using an integrated luminosity of 42.7 pb**{-1}. The cross sections are given for photon-proton centre-of-mass energies in the range 134< W <277 GeV. The differential cross sections as a function of the

Bahram Mashhoon

The physical basis of the standard theory of general relativity is examined and a nonlocal theory of accelerated observers is described that involves a natural generalization of the hypothesis of locality. The nonlocal theory is confronted with experiment via an indirect approach. The implications of the results for gravitation are briefly discussed.

Hossein Farajollahi, Hugh Luckock

In the canonical approach to general relativity it is customary to parametrize the phase space by initial data on spacelike hypersurfaces. However, if one seeks a theory dealing with observations that can be made by a single localized observer, it is natural to use a different description of the phase space. This results in a different set of Dirac observabl

Pawel Wocjan, Dominik Janzing, Thomas Beth

A lower bound on the chromatic number of a graph is derived by majorization of spectra of weighted adjacency matrices. These matrices are given by Hadamard products of the adjacency matrix and arbitrary Hermitian matrices.

P. T. Coleridge, A. S. Sachrajda, P. Zawadzki

Magnetoresistance results are presented for p-SiGe samples on the metallic side of the B=0 metal-insulator transition. It was possible to separate the weak localisation and Zeeman interaction effects but the results could not be explained quantitatively within the framework of standard theories for quantum corrections of a weakly interacting 2-dimensional sy

J. J. Lin, Y. L. Zhong, T. J. Li

We have studied the effect of thermal annealing on electron dephasing times $τ_ϕ$ in three-dimensional polycrystalline metals. Measurements are performed on as-sputtered and annealed AuPd and Sb thick films, using weak-localization method. In all samples, we find that $τ_ϕ$ possesses an extremely weak temperature dependence as $T \to 0$. Our results show tha

E. Bascones, A. A. Burkov, A. H. MacDonald

Nesting in a semimetal can lead to an excitonic insulator state with spontaneous coherence between conduction and valence bands and a gap for charged excitations. In this paper we present a theory of the ferromagnetic state that occurs when the density of electrons in the conduction band and holes in the valence band differ. We find an unexpectedly rich dopi

V. L. Pokrovsky, N. A. Sinitsyn

We present an exact asymptotic solution for electron transition amplitudes in an infinite linear chain driven by an external homogeneous time-dependent electric field. This solution extends the Landau-Zener theory for the case of infinite number of states in discrete spectrum. In addition to transition amplitudes we calculate an effective diffusion constant.

T. Ihn, T. Vancura, A. Baumgartner, P. Studerus

The implementation of a tuning fork sensor in a scanning force microscope operational at 300 mK is described and the harmonic oscillator model of the sensor is motivated. These sensors exhibit very high quality factors at low temperatures. The nested feedback comprising the sensor, a phase locked loop and a conventional $z$-feedback is analyzed in terms of l

Vincent Hakim, Anaël Lemaître, Kirone Mallick

Recent experiments on mesoscopic samples and theoretical considerations lead us to analyze multiply charged ($n>1$) vortex solutions of the Ginzburg-Landau equations for arbitrary values of the Landau-Ginzburg parameter $κ$. For $n\gg 1$, they have a simple structure and a free energy ${\cal F}\sim n$. In order to relate this behaviour to the classic Abrikos

C. Artini, M. M. Carnasciali, G. A. Costa, M. Ferretti

We report on structural, electrical and magnetic properties of RuSr2GdCu2O8 samples made by systematic synthesis work so that they differ from one onether in number of annealings and sintering temperature. Our aim is to highlight the different behaviours as a consequence of the thermal treatments. In particular, we deal with the onset of superconductivity in

Gen Tatara

Response of the electronic current through an Aharonov-Bohm ring after a two-level-system is switched on is calculated perturbatively by use of non-equilibrium Green function. In the ballistic case the amplitude of the Aharonov-Bohm oscillation is shown to decay to a new equilibrium value due to scattering into other electronic states. Relaxation of Altshule

L. Santos, G. V. Shlyapnikov

We analyze the implosion and subsequent explosion of a trapped condensate after the scattering length is switched to a negative value. Our results compare very well qualitatively and fairly well quantitatively with the results of recent experiments at JILA.

Jin Nakamura, Masamitsu Watanabe, Tamio Oguchi, Sin-ya Nasubida

X-ray emission (XES) and absorption (XAS) spectra near the B-$K$ edge were measured on single-crystalline AlB$_2$ compound which is an isostructural diboride of superconducting MgB$_2$. The partial density of states (PDOS) of B-2$pσ$ and $pπ$ orbitals were derived from the polarization dependence of XES and XAS spectra. There are considerable amounts of PDOS

Kanwal Jeet Singh, Sujeet Chaudhary, M. K. Chattopadhyay, M. A. Manekar

The magnetotransport behaviour is investigated in detail across the first order magnetic phase transition from ferromagnetic to antiferromagnetic state in polycrystalline Ce(Fe$_{0.96}$Al$_{0.04}$)$_2$ sample. The study clearly brings out various generic features associated with a first order transition, viz., hysteresis, phase coexistence, supercooling and

Megan Donahue, Jennifer Mack, Caleb Scharf, Paul Lee

We present a comparison of X-ray and optical luminosities and luminosity functions of cluster candidates from a joint optical/X-ray survey, the ROSAT Optical X-Ray Survey. Completely independent X-ray and optical catalogs of 23 ROSAT fields (4.8 deg2) were created by a matched-filter optical algorithm and by a wavelet technique in the X-ray. We directly comp

Megan Donahue, Caleb Scharf, Jennifer Mack, Paul Lee

We present and analyze the optical and X-ray catalogs of moderate-redshift cluster candidates from the ROSAT Optical X-ray Survey, or ROXS. The survey covers 4.8 square degrees (23 ROSAT PSPC pointings). The cross-correlated cluster catalogs were constructed by comparing two independent catalogs extracted from the optical and X-ray bandpasses, using a matche

B. G. Elmegreen

Three-dimensional fractal models on grids of 200**3 pixels are generated from the inverse Fourier transform of noise with a power law cutoff, exponentiated to give a log normal distribution of density. The fractals are clipped at various intensity levels and the mass and size distribution functions of the clipped peaks and their subpeaks are determined. Thes

D. M. Elmegreen, B. G. Elmegreen, K. S. Eberwein

The structure of dust spirals in the nuclei of the SAab-type Liner galaxies NGC 4450 and NGC 4736 is studied using archival HST PC images. The spirals are typically only several hundredths of a magnitude fainter than the neighboring disks, so unsharp mask techniques are used to highlight them. The ambient extinction is estimated to be less than 0.1 mag from

Irit Maor, Ram Brustein, Jeff McMahon, Paul J. Steinhardt

We explore various pitfalls and challenges in determining the equation-of-state (w) of dark energy component that dominates the universe and causes the current accelerated expansion. We demonstrated in an earlier paper the existence of a degeneracy that makes it impossible to resolve well the value of w or its time-derivative with supernovae data. Here we co

S. M. Andrievsky, V. V. Kovtyukh, R. E. Luck, J. R. D. Lepine

A number of studies of abundance gradients in the galactic disk have been performed in recent years. The results obtained are rather disparate: from no detectable gradient to a rather significant slope of about -0.1 dex kpc -1. The present study concerns the abundance gradient based on the spectroscopic analysis of a sample of classical Cepheids. These stars

Ofer Lahav

Observational tests for the Cosmological Principle are reviewed. Assuming the FRW metric we then summarize estimates of cosmological parameters from various data sets, in particular the Cosmic Microwave Background and the 2dF galaxy redshift survey. These and other analyses suggest a best-fit Lambda-Cold Dark Matter model with Omega_m = 1 - Omega_lambda = 0.

Christopher Gordon

This PhD thesis presents a study of the effect and generation of non-adiabatic perturbations in Cosmology. We study adiabatic (curvature) and entropy (isocurvature) perturbations produced during a period of cosmological inflation that is driven by multiple scalar fields with an arbitrary interaction potential. A local rotation in field space is performed to

Jill Bechtold

The absorption lines observed in quasar spectra have given us a detailed picture of the intergalactic medium and the metal abundance and kinematics of high redshift galaxies. In this review, we present an introduction to the field, starting with the techniques used for interpreting absorption line spectra. We then survey the observational and theoretical dev

Makoto Kishimoto, Laura E. Kay, Robert Antonucci, Todd W. Hurt

We present the results of UV imaging polarimetry of the Seyfert 2 galaxy Mrk 477 taken by the Faint Object Camera onboard the Hubble Space Telescope (HST). From a previous HST UV image (lambda ~ 2180A), Mrk 477 has been known to have a pointlike bright UV hotspot in the central region, peculiar among nearby Seyfert 2 galaxies. There are also claims of UV/opt

H. W. Moos, K. R. Sembach, A. Vidal-Madjar, D. G. York

Observations obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) have been used to determine the column densities of D I, O I, and N I along seven sight lines that probe the local interstellar medium (LISM) at distances from 37 pc to 179 pc. Five of the sight lines are within the Local Bubble and two penetrate the surrounding H I wall. Reliable v

D. J. Thompson, S. W. Digel, P. L. Nolan, O. Reimer

At least three pulsars in supernova remnants were detected at E > 100 MeV by EGRET on the Compton Gamma Ray Observatory. Efforts to search for additional pulsars in the EGRET data have been unsuccessful due to limited statistics. An example is the recently-discovered radio pulsar J2229+6114, where efforts to search the EGRET data using several different meth

S. McBreen, F. Quilligan, B. McBreen, L. Hanlon

A temporal analysis has been performed on a sample of 100 bright gamma-ray bursts (GRBs) with T90<2s from the BATSE current catalog. The GRBs were denoised using a median filter and subjected to an automated pulse selection algorithm as an objective way of idenitifing the effects of neighbouring pulses. The rise times, fall times, FWHM, pulse amplitudes and

A. Fassia, W. P. S. Meikle, J. Spyromilio

We present near-infrared spectroscopic observations of SN 1987A covering the period 1358 to 3158 days post-explosion. This is the first time that IR spectra of a supernova have been obtained to such late epochs. The spectra comprise emission from both the ejecta and the bright, ring-shaped circumstellar medium (CSM). The most prominent CSM emission lines are

F. Quilligan, B. McBreen, L. Hanlon, S. McBreen

A comprehensive temporal analysis has been performed on the 319 brightest GRBs with T90>2s from the BATSE current catalog. The rise times, fall times, full-widths at half maximum (FWHM), pulse amplitudes and pulse areas were measured and the frequency distributions are presented here. The distribution of time intervals between pulses is not random but compat

G. Ghirlanda, A. Celotti, G. Ghisellini

We present the time integrated and time resolved spectral analysis of a sample of bright bursts selected from the BATSE archive. We fitted four different spectral models to the time integrated and time resolved spectra of the flux pulses. We point out that the found (marginal) differences in the parameter distributions can be ascribed to the different spectr

S. M. Andrievsky, D. Bersier, V. V. Kovtyukh, R. E. Luck

Based on spectra obtained at the Anglo-Australian Observatory, we present a discussion of the metallicity of the galactic disc derived using Cepheids at galactocentric distances 4-6 kpc. Our new results together with previous gradient determination (Paper I) show that the overall abundance distribution within the galactocentric distances 4-11 kpc cannot by r

R. Manka, M. Zastawny-Kubica, A. Brzezina, I. Bednarek

In this paper the effect of the magnetic field on the form of the equation of state and helium white dwarfs structure are discussed. The influence of the temperature and magnetic field on white dwarfs parameters have been investigated. The mass-radius relations for different parameters were obtained. The occurrence of unstable branches in the mass-radius rel

Wlodzimierz Piechocki

We examine the dependence of quantization on global properties of a classical system. Quantization based on local properties may lead to ambiguities and inconsistency between local and global symmetries of a quantum system. Our quantization method based on global characteristics has sound foundation. Presented results give insight into the nature of removabl

H. Beuther, P. Schilke, T. K. Sridharan, K. M. Menten

We present a mapping study of massive molecular outflows in 26 high-mass star-forming regions at 11&#39;&#39; spatial resolution. Bipolar morpholgy is found in 80% of the sources and the collimation is higher than previously thought. Additionally, we find that well known low-mass correlations continue up to the high-mass regime, and accretion rates are aroun

R. Stepanov, P. Frick, A. Shukurov, D. Sokoloff

We suggest a two-dimensional wavelet devised to deduce the large-scale structure of a physical field (e.g., the Galactic magnetic field) from its integrals along straight paths from irregularly spaced data points to a fixed interior point (the observer). The method can be applied to the analysis of pulsar rotation and dispersion measures in terms of the larg

Ilian T. Iliev, Paul R. Shapiro

Dark-matter halos are the scaffolding around which galaxies and clusters are built. They form when the gravitational instability of primordial density fluctuations causes regions which are denser than average to slow their cosmic expansion, recollapse, and virialize. Objects as different in size and mass as dwarf spheroidal galaxies and galaxy clusters are p

L. C. Garcia de Andrade, G. A. Monerat

Oscillating phases in Bianchi type IX anisotropic universes are obtained as linearized solutions of Einstein-Cartan theory of gravity.Instead of making use of Weyssenhoff spinning fluids we addopt axionic torsion matter where the torsion tensor is totally skew-symmetric as in Kalb-Rammond type theories.Spin-torsion,metric and matter density oscillate at diff

Cheng-Wei Chiang, Jonathan L. Rosner

New data from the BaBar, Belle, and CLEO Collaborations on B decays to two-body charmless final states are analyzed, with the following consequences: (1) The penguin amplitude which dominates the decay $B^+ \to π^+ K^{*0}$ has a magnitude similar to that dominating $B^+ \to π^+ K^0$. (2) The decay $B^+ \to π^+ η$, a good candidate for observing direct CP vio

Leif Lonnblad

An algorithm is presented in which the Colour-Dipole Cascade Model as implemented in the Ariadne program is corrected to match the fixed order tree-level matrix elements for e+e- -> n jets. The result is a full parton level generator for e+e- annihilation where the generated states are correct on tree-level to fixed order in alpha_S and to all orders with mo

Soebur Razzaque, Surujhdeo Seunarine, David Z. Besson, Douglas W. McKay

Radio Cherenkov radiation is arguably the most efficient mechanism for detecting showers from ultra-high energy particles of 1 PeV and above. Showers occuring in Antarctic ice should be detectable at distances up to 1 km. We report on electromagnetic shower development in ice using a GEANT Monte Carlo simulation. We have studied energy deposition by shower p

Gregory F. Lawler, Oded Schramm, Wendelin Werner

We prove that the scaling limit of loop-erased random walk in a simply connected domain $D$ is equal to the radial SLE(2) path in $D$. In particular, the limit exists and is conformally invariant. It follows that the scaling limit of the uniform spanning tree in a Jordan domain exists and is conformally invariant. Assuming that the boundary of the domain is

V. A. De Lorenci, E. S. Moreira,

Vacuum polarization of a massive scalar field in the background of a two-dimensional version of a spinning cosmic string is investigated. It is shown that when the `radius of the universe&#39; is such that spacetime is globally hyperbolic the vacuum fluctuations are well behaved, diverging though on the `chronology horizon&#39;. Naive use of the formulae whe

S. Urazhdin, D. Bilc, S. H. Tessmer, S. D. Mahanti

Scanning tunneling spectroscopy images of Bi$_2$Se$_3$ doped with excess Bi reveal electronic defect states with a striking shape resembling clover leaves. With a simple tight-binding model we show that the geometry of the defect states in Bi$_2$Se$_3$ can be directly related to the position of the originating impurities. Only the Bi defects at the Se sites

Thomas Dent, Malcolm Fairbairn

We investigate the dependence of the nucleon-nucleon force in the deuteron system on the values of coupling strengths at high energy, which will in general depend on the geometry of extra dimensions. The stability of deuterium at all times after nucleosynthesis sets a bound on the time variation of the ratio of the QCD confinement scale to light quark masses

Tadashi Takayanagi, Tadaoki Uesugi

In this paper we reexamine the D-brane spectrum in the Melvin background with nonconstant NSNS B-field from the viewpoint of its world-volume and string world-sheet theory. We find that the stable D2-D0 bound state exists even though it does not wrap any nontrivial cycles. We show that this system is stabilized by the presence of the NSNS B-field and the mag

Junpei Harada, Shoji Hashimoto, Ken-Ichi Ishikawa, Andreas S. Kronfeld

We apply heavy-quark effective theory to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this approach, the inverse heavy-quark mass and the lattice spacing are treated as short distances, and their effects are lumped into short-distance coefficients. We show how to use this formalism to match lattice gauge theory to con

Priscilla C. Frisch

The development of our understanding of the gaseous component of the interstellar medium is reviewed. During the 20th century our picture of diffuse material in space has grown from a simple model of isolated clouds in thermal equilibrium with stellar radiation fields to one of a richly varied composite of materials with a wide range of physical properties a

Shamit Kachru, John Pearson, Herman Verlinde

We consider the dynamics of p anti-D3 branes inside the Klebanov-Strassler geometry, the deformed conifold with M units of RR 3-form flux around the S^3. We find that for p<<M the system relaxes to a nonsupersymmetric NS 5-brane ``giant graviton&#39;&#39; configuration, which is classically stable, but quantum mechanically can tunnel to a nearby supersymmetr

Alessandro Drago, Marina Gibilisco, Claudia Ratti

We interpret lattice data for the equation of state of pure gauge $SU(3)_c$ by an evaporation model. At low temperatures gluons are frozen inside the gluon condensate, whose dynamics is described in terms of a dilaton lagrangian. Above the critical temperature quasi-free gluons evaporate from the condensate: a first order transition is obtained by minimizing

S. Gardner, Ulf-G. Meißner

We examine the role of B^0(\bar B^0) \to σπ^0 \to π^+π^- π^0 decay in the Dalitz plot analysis of B^0 (\bar B^0) \to ρπ\to π^+π^-π^0 decays, employed to extract the CKM parameter α. The σπchannel is significant because it can break the relationship between the penguin contributions in B\toρ^0π^0, B\toρ^+π^-, and B\toρ^-π^+ decays consequent to an assumption

Jurgen Schaffner-Bielich

The equation of state for compact stars is reviewed with special emphasis on the role of strange hadrons, strange dibaryons and strange quark matter. Implications for the properties of compact stars are presented. The importance of neutron star data to constrain the properties of hypothetic particles and the possible existence of exotic phases in dense matte

A. Barrau, G. Boudoul, F. Donato, D. Maurin

Primordial black holes (PBHs) have motivated many studies since it was shown that they should evaporate and produce all kinds of particles. Recent experimental measurements of cosmic rays with great accuracy, theoretical investigations on the possible formation mechanisms and detailed evaporation processes have revived the interest in such astrophysical obje

E. Gava, K. S. Narain, M. H. Sarmadi

We study Little String Theories (LST) with ${\cal N}=(1,0)$ supersymmetry arising, in a suitable double scaling limit, from 5-branes in heterotic string theory or in the heterotic-like type II/$(-)^{F_L}\times {\rm shift}$. The limit in question, previously studied in the type II case, is such that the resulting holographically dual pairs, i.e. bulk string t

N. S. Schulz, W. N. Brandt

The luminous X-ray binary Circinus X-1 has been observed twice near zero orbital phase using the High-Energy Transmission Grating Spectrometer (HETGS) onboard Chandra. The source was in a high-flux state during a flare for the first observation, and it was in a low-flux state during a dip for the second. Spectra from both flux states show clear P Cygni lines

P. E. Jönsson, H. Yoshino, P. Nordblad, H. Aruga Katori

Non-equilibrium dynamics of three dimensional model spin glasses - the Ising system Fe$_{0.50}$Mn$_{0.50}$TiO$_3$ and the Heisenberg like system Ag(11 at% Mn) - has been investigated by measurements of the isothermal time decay of the low frequency ac-susceptibility after a quench from the paramagnetic to the spin glass phase. It is found that the relaxation

E. A. Yelland, J. R. Cooper, A. Carrington, N. E. Hussey

We report observations of quantum oscillations in single crystals of the high temperature superconductor MgB_2. Three de Haas-van Alphen frequencies are clearly resolved. Comparison with band structure calculations strongly suggests that two of these come from a single warped Fermi surface tube along the c direction, and that the third arises from cylindrica

Glenn Watson, John R. Klauder

At a fixed point in spacetime (say, x_0), gravitational phase space consists of the space of symmetric matrices F^{ab} [corresponding to the canonical momentum pi^{ab}(x_0) and of symmetric matrices {G_{ab}}[corresponding to the canonical metric g_{ab}(x_0), where 1 \leq a,b \leq n, and, crucially, the matrix {G_{ab}} is necessarily positive definite, i.e. \

Tomotsugu Goto, Maki Sekiguchi, Robert C. Nichol, Neta A. Bahcall

We describe an automated method, the Cut & Enhance method (CE) for detecting clusters of galaxies in multi-color optical imaging surveys. This method uses simple color cuts, combined with a density enhancement algorithm, to up-weight pairs of galaxies that are close in both angular separation and color. The method is semi-parametric since it uses minimal ass

C. Alexandrou, Ph. de Forcrand, E. Follana

We extend our study of the gluon propagator in quenched lattice QCD using the Laplacian gauge to a finer lattice. We verify the existence of a pole mass as we take the continuum limit and deduce a value of $\sim 600^{+150}_{-30}$ MeV for this pole mass. We find a finite value of $(454(5){\rm MeV})^{-2}$ for the renormalized zero-momentum propagator, in agree

Henrique Boschi-Filho, Nelson R. F. Braga

The AdS/CFT correspondence can be realized in spaces that are globally different but share the same asymptotic behavior. Two known cases are: a compact AdS space and the space generated by a large number of coincident branes. We discuss the physical consistency, in the sense of the Cauchy problem, of these two formulations. We show that the role of the bound

Michail P. Rekalo, Egle Tomasi-Gustafsson

We show that for the S-state $π^0$-production in processes $γ+d\to d+π^0$ and $e^-+d\to e^-+d+π^0$ the rescattering effects due to the transition: $ γ+d\to p+p+π^-$ (or $n+n+π^+)\to d+π^0$ are cancelled out due to the Pauli principle. The large values for these effects predicted in the past may result from the fact that the spin structure of the correspondin

F. Simkovic, V. E. Lyubovitskij, Th. Gutsche, A. Faessler

The non-photonic neutrino exchange mechanism of the lepton flavor violating muon-electron conversion in nuclei is revisited. First we determine the nucleon coupling constants for the neutrino exchange mechanism in a relativistic quark model taking into account quark confinement and chiral symmetry requirements. This includes a new, previously overlooked tree

K. Zyczkowski, W. Slomczynski, M. Kus, H. -J. Sommers

An ensemble of random unistochastic (orthostochastic) matrices is defined by taking squared moduli of elements of random unitary (orthogonal) matrices distributed according to the Haar measure on U(N) (or O(N), respectively). An ensemble of symmetric unistochastic matrices is obtained with use of unitary symmetric matrices pertaining to the circular orthogon

T. Rauscher, A. Heger, R. D. Hoffman, S. E. Woosley

We present the first calculations to follow the evolution of all stable nuclei and their radioactive progenitors in stellar models computed from the onset of central hydrogen burning through explosion as Type II supernovae. Calculations are performed for Pop I stars of 15, 19, 20, 21, and 25 M_sun using the most recently available experimental and theoretica

M. B. Gay Ducati, K. Kontros, A. Lengyel, M. V. T. Machado

Electroproduction in deep inelastic scattering at HERA is studied in a model considering a finite sum of gluon ladders, associated with a truncation of the BFKL series. The approach contains the bare two gluon exchange and both one and two rungs contributions. The model is fitted to the data on the inclusive structure function F_2(x,Q^2) in the region x<0.02

Amy E. Reines, Geoffrey W. Marcy

We have searched for nonastrophysical emission lines in the optical spectra of 577 nearby F, G, K, and M main-sequence stars. Emission lines of astrophysical origin would also have been detected, such as from a time--variable chromosphere or infalling comets. We examined ~20 spectra per star obtained during four years with the Keck/HIRES spectrometer at a re

Stefan Forste

We discuss D-branes on a line of conformal field theories connected by an exact marginal deformation. The line contains an SU(2) WZW model and two mutually T-dual SU(2)/U(1) cosets times a free boson. We find the D-branes preserving a U(1) isometry, an F-flux quantization condition and conformal invariance. Away from the SU(2) point a U(1) times U(1) symmetr

M. Diehl, P. Kroll, C. Vogt

We investigate the soft handbag contribution to two-photon annihilation into pion or kaon pairs at large energy and momentum transfer. The amplitude is expressed as a hard gamma gamma -> q qbar subprocess times a form factor describing the soft transition from q qbar to the meson pair. We find the calculated angular dependence of the cross section in good ag

David L. Nidever, Geoffrey W. Marcy, R. Paul Butler, Debra A. Fischer

We report radial velocities for 844 FGKM-type main sequence and subgiant stars and 45 K giants, most of which had either low-precision velocity measurements or none at all. These velocities differ from the standard stars of Udry et al. by 0.035 km/s (RMS) for the 26 FGK standard stars in common. The zero-point of our velocities differs from that of Udry et a

L. Hoffmann, L. Mesref, A. Meziane, W. Rühl

We develop a recursive algorithm for the investigation of infinite sequences of quasi-primary fields obtained from chiral primary operators (CPOs) $O^I_k(x)$ and eventually their derivatives by applying operator product expansions and singling out SO(6) representations. We show that normal products of $O_2$ operators can be expressed in terms of projection o