April 2000 arXiv papers — page 10

Kenneth J. Mighell

Astrometry, on the International Celestial Reference Frame (epoch J2000.0), is presented for the Walker (1994, PASP, 106, 828) stars in the Omega Centauri (= NGC 5139 = C1323-1472) Hubble Space Telescope Wide Field/Planetary Camera (WF/PC) calibration field of Harris et al. (1993, AJ, 105, 1196). Harris et al. stars were first identified on a WFPC2 observati

A. E. Hornschemeier, W. N. Brandt, G. P. Garmire, D. P. Schneider

We present first results from an X-ray study of the Hubble Deep Field North (HDF-N) and its environs obtained using 166 ks of data collected by the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. This is the deepest X-ray observation ever reported, and in the HDF-N itself we detect six X-ray sources down to a 0.5--8 keV flux

Gáspár Á. Bakos, József M. Benkő, Johanna Jurcsik

We present identification and astrometry of all previously known or suspected variables along with the discovery of six new variables in the globular cluster M3. The number of the catalogized variables increased to 274 by including all the confirmed, previously known variables and the new discoveries. The precise and homogeneous astrometry, as well as the cl

Hugo Delgado-Marti, Alan M. Levine, Eric Pfahl, Saul A. Rappaport

We have observed the Be/X-ray pulsar binary system X Per/4U 0352+30 on 61 occasions spanning an interval of 600 days with the PCA instrument on RXTE. Pulse timing analyses of the 837-s pulsations yield strong evidence for the presence of orbital Doppler delays. We confirm the Doppler delays by using measurements made with the RXTE All-Sky Monitor. We obtain

Remo Ruffini, Jay D. Salmonson, James R. Wilson, She-Sheng Xue

The interaction of an expanding Pair-Electromagnetic pulse (PEM pulse) with a shell of baryonic matter surrounding a Black Hole with electromagnetic structure (EMBH) is analyzed for selected values of the baryonic mass at selected distances well outside the dyadosphere of an EMBH. The dyadosphere, the region in which a super critical field exists for the cre

Andreas Brunthaler, Heino Falcke, Geoffrey C. Bower, M. F. Aller

So far all relativistically boosted jets with superluminal motion have only been detected in typical radio galaxies with early type host galaxies. We have now discovered superluminal motion in the Seyfert I galaxy III Zw 2, classified as a spiral. Superluminal motion was first inferred from the spectral evolution of the source and then confirmed by VLBI obse

Eamonn Kerins

The Andromeda galaxy (M31) provides a new line of sight for Galactic MACHO studies and also a signature, near-far asymmetry, which may establish the existence of MACHOs in the M31 halo. We outline the principles behind the so-called ``pixel-lensing'' experiments monitoring unresolved stars in M31. We present detailed simulations of the POINT-AGAPE su

Alfred Krabbe

The SOFIA telescope as the heart of the observatory is a major technological challenge. I present an overview on the astro-nomical and scientific requirements for such a big airborne observatory and demonstrate the impact of these requirements on the layout of SOFIA, in particular on the telescope design as it is now. Selected components of the telescope wil

P. M. Wallace, D. L. Bertsch, S. D. Bloom, N. J. Griffis

The 3rd EGRET Catalog of High-energy Gamma-ray Sources contains 170 unidentified sources, and there is great interest in the nature of these sources. One means of determining source class is the study of flux variability on time scales of days; pulsars are believed to be stable on these time scales while blazars are known to be highly variable. In addition,

P. E. Nissen, M. Asplund, V. Hill, S. D'Odorico

A high resolution (R = 110.000), very high S/N (>600) spectrum of the metal-poor turnoff star G271-162 has been obtained in connection with the commissioning of UVES at VLT/Kueyen. Using both 1D hydrostatic and 3D hydrodynamical model atmospheres, the lithium isotope ratio has been estimated from the LiI 670.8 nm line by means of spectral synthesis. The nece

H M Bryce, M A Hendry

We have developed a code to compute multi-colour microlensing lightcurves for extended sources, including the effects of limb darkening and photospheric star spots as a function of spot temperature, position, size and lens trajectory. Our model also includes the effect of structure within the spot and rotation of the stellar source. Our results indicate that

Helmut Jerjen, Agris Kalnajs, Bruno Binggeli

We present the 2-D photometric decomposition of the Virgo galaxy IC3328. The analysis of the global light distribution of this morphologically classified nucleated dwarf elliptical galaxy (dE1,N) reveals a tightly wound, bi-symmetric spiral structure with a diameter of 4.5 kpc, precisely centered on the nucleus of the dwarf. The amplitude of the spiral is on

Hyun-chul Lee, Suk-Jin Yoon, Young-Wook Lee

The strength of the H$β$ index has been computed for the integrated spectra of model globular clusters from the evolutionary population synthesis. These models take into account, for the first time, the detailed systematic variation of horizontal-branch (HB) morphology with age and metallicity. Our models show that the H$β$ index is significantly affected by

S. S. Hasan, W. Kalkofen, A. A. van Ballegooijen

We examine the excitation of oscillations in the magnetic network of the Sun through the footpoint motion of photospheric magnetic flux tubes located in intergranular lanes. The motion is derived from a time series of high-resolution G band and continuum filtergrams using an object-tracking technique. We model the response of the flux tube to the footpoint m

Joseph J. Mohr, Zoltan Haiman, Gilbert P. Holder

The properties of nearby galaxy clusters limit the range of cosmological parameters consistent with our universe. We describe the limits which arise from studies of the intracluster medium (ICM) mass fraction fICM and consideration of the possible sources of systematic error: Omega_M<0.44h_{50}^{-1/2} at 95% confidence. We emphasize that independent of Type

D. Rusin

Measured time delays between the images of a gravitationally lensed source can lead to a determination of the Hubble constant ($H_o$), but only if the lensing mass distribution is well understood. The inability to sufficiently constrain galaxy mass models results in large uncertainties on the derived $H_o$, and severely hampers the cosmological application o

L. V. E. Koopmans, A. G. de Bruyn

We present the first unambiguous case of external variability of a radio gravitational lens, CLASS B1600+434. The VLA 8.5-GHz difference light curve of the lensed images, taking the proper time-delay into account, shows the presence of external variability with 14.6-sigma confidence. We investigate two plausible causes of this external variability: scatterin

Murat Gunaydin, Marco Zagermann

We show that certain five dimensional, N=2 Yang-Mills/Einstein supergravity theories admit the gauging of the full R-symmetry group, SU(2)_R, of the underlying N=2 Poincare superalgebra. This generalizes the previously studied Abelian gaugings of U(1)_R subgroup of SU(2)_R and completes the construction of the most general vector and tensor field coupled fiv

Anirban Chakraborti, Bikas K. Chakrabarti

We consider a simple model of a closed economic system where the total money is conserved and the number of economic agents is fixed. In analogy to statistical systems in equilibrium, money and the average money per economic agent are equivalent to energy and temperature, respectively. We investigate the effect of the saving propensity of the agents on the s

S. P. de Alwis, A. T. Flournoy, N. Irges

We argue that traditional methods of compactification of string theory make it very difficult to understand how the cosmological constant becomes zero. String inspired models can give zero cosmological constant after fine tuning but since string theory has no free parameters it is not clear that this is allowed. Brane world scenarios on the other hand while

David Garfinkle, Robert Mann

We find an expression for the generalized gravitational entropy of Hawking in terms of Noether charge. As an example, the entropy of the Taub-Bolt spacetime is calculated.

Ian Low, A. Zee

We add a Gauss-Bonnet term to the Einstein-Hilbert action and study the recent proposal to solve the cosmological constant problem. We also consider the possibility of adding a dilaton potential to the action. In the absence of supersymmetry, we obtain first order Bogomol&#39;nyi equation as a solution-generating method in our scenario. When the coefficient

S. L. Cornish, N. R. Claussen, J. L. Roberts, E. A. Cornell

Bose-Einstein condensation has been achieved in a magnetically trapped sample of 85Rb atoms. Long-lived condensates of up to 10^4 atoms have been produced by using a magnetic-field-induced Feshbach resonance to reverse the sign of the scattering length. This system provides many unique opportunities for the study of condensate physics. The variation of the s

Ernst Joachim Weniger, Bernard Kirtman

Quasi-onedimensional stereoregular polymers as for example polyacetylene are currently of considerable interest. There are basically two different approaches for doing electronic structure calculations: One method is essentially based on concepts of solid state theory. The other method is essentially a quantum chemical method since it approximates the polyme

Philip Pearle

It is emphasized that the collapse postulate of standard quantum theory can violate conservation of energy-momentum and there is no indication from where the energy-momentum comes or to where it goes. Likewise, in the Continuous Spontaneous Localization (CSL) dynamical collapse model, particles gain energy on average. In CSL, the usual Schrödinger dynamics i

J. Alexandre, K. Farakos, G. Koutsoumbas

We solve the Schwinger-Dyson equations for QED in 2+1 or 3+1 dimensions in the presence of a strong homogeneous external magnetic field. The magnetic field is assumed strong enough, so that the lowest Landau level approximation holds, but the usual assumption of a momentum-independent self-energy is not made. In 2+1 dimensions, the scaling with logarithm cha

Todor M. Mishonov

A novel experiment for determination of the charge related to vortices in thin superconducting film is proposed and a number of related experimental set-ups are also theoretically considered. The methods are based on the Torricelli-Bernoulli effect in superconductors and the phenomenology of the effect is briefly discussed. The vortex charge is expressed via

Christophe Texier

We study the distribution of the $n$-th energy level for two different one-dimensional random potentials. This distribution is shown to be related to the distribution of the distance between two consecutive nodes of the wave function. We first consider the case of a white noise potential and study the distributions of energy level both in the positive and th

Zoltan Kadar

The torus and the Klein bottle amplitude coefficients are computed in permutation orbifolds of RCFT-s in terms of the same quantities in the original theory and the twist group. An explicit expression is presented for the number of self conjugate primaries in the orbifold as a polynomial of the total number of primaries and the number of self conjugate ones

P. P. Avelino, J. P. M. de Carvalho, C. J. A. P. Martins, J. C. R. E. Oliveira

We show that our Universe may be inhomogeneous on large sub-horizon scales without us being able to realise it. We assume that a network of domain walls permeates the universe dividing it in domains with slightly different vacuum energy densities. We require that the energy scale of the phase transition which produced the domain walls is sufficiently low so

Bumsoo Kyung

The interplay between antiferromagnetism and d-wave superconductivity is studied in a mean-field approximation for a generic microscopic Hamiltonian with short-range repulsion and near-neighbor attraction. In the presence of competing microscopic interactions, the phase boundaries of antiferromagnetic and superconducting states are significantly modified in

Juan P. Garrahan, Esteban Moro, David Sherrington

We study the continuous time dynamics of the Thermal Minority Game. We find that the dynamical equations of the model reduce to a set of stochastic differential equations for an interacting disordered system with non-trivial random diffusion. This is the simplest microscopic description which accounts for all the features of the system. Within this framework

Orlando Alvarez

A set of on shell duality equations is proposed that leads to a map between strings moving on symmetric spaces with opposite curvatures. The transformation maps &#34;waves&#34; on a riemannian symmetric space to &#34;waves&#34; on its dual riemannian symmetric space. This transformation preserves the energy momentum tensor though it is not a canonical transf

Holger Lyre

Gauge field theories may quite generally be defined as describing the coupling of a matter-field to an interaction-field, and they are suitably represented in the mathematical framework of fiber bundles. Their underlying principle is the so-called gauge principle, which is based on the idea of deriving the coupling structure of the fields by satisfying a pos

Moritz Hoeffe, Michael Baake

Diffuse scattering is usually associated with some disorder in the analyzed material. Different kinds of disorder may produce different diffuse scattering -- or not. In this letter, we demonstrate some aspects of the variety of diffuse scattering that occurs even in very simple examples, and how unawareness may lead astray.

A. Kostyuk, M. Gorenstein, H. Stoecker, W. Greiner

The quantum mechanical formula for Mayer&#39;s second cluster integral for the gas of relativistic particles with hard-core interaction is derived. The proper pion volume calculated with quantum mechanical formula is found to be an order of magnitude larger than its classical evaluation. The second cluster integral for the pion gas is calculated in quantum m

Kazuo Fujikawa

A specific algebraic realization of the Ginsparg-Wilson relation in the form $γ_{5}(γ_{5}D)+(γ_{5}D)γ_{5} = 2a^{2k+1}(γ_{5}D)^{2k+2}$ is discussed, where $k$ stands for a non-negative integer and $k=0$ corresponds to the commonly discussed Ginsparg-Wilson relation. From a view point of algebra, a characteristic property of our proposal is that we have a clos

D. N. Aristov, S. V. Maleyev

We discuss the influence of the Dzyaloshinskii-Moriya (DM) interaction in the Heizenberg spin chain model for the observables in the polarized neutron scattering experiments. We show that different choices of the parameters of DM interaction may leave the spectrum of the problem unchanged, while the observable spin-spin correlation functions may differ quali

Juergen Audretsch, Vladimir D. Skarzhinsky, Boris L. Voronov

We consider the elastic scattering and bound states of charged quantum particles moving in the Aharonov-Bohm and an attractive $ρ^{-2}$ potential in a partial wave approach. Radial solutions of the stationary Schrödinger equation are specified in such a way that the Hamiltonian of the problem is self-adjoint. It is shown that they are not uniquely fixed but

R. V. Gavai, Sourendu Gupta

We have studied, for the first time, screening masses obtained from glueball-like correlators in Quantum Chromodynamics with four light dynamical flavours of quarks in the temperature range 1.5T_c < T < 3T_c, where T_c is the temperature at which the chiral transition occurs. We have also studied pion-like and sigma-like screening masses, and found that they

R. Sagar, V. Mohan, S. B. Pandey, A. K. Pandey

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ~ 1.5 day after the gamma-ray burst. In fact we provide the earliest optical observations for this burst. Light curves of the afterglow emissions in U, B, V, R, I, J and K&#39; passbands are obtained by combining the present measurement

Anders Johansen, Didier Sornette

The Nasdaq Composite fell another $\approx 10 %$ on Friday the 14'th of April 2000 signaling the end of a remarkable speculative high-tech bubble starting in spring 1997. The closing of the Nasdaq Composite at 3321 corresponds to a total loss of over 35% since its all-time high of 5133 on the 10'th of March 2000. Similarities to the speculative bubble preced

P. O. Fedichev, A. E. Muryshev

We develop a theory of dissipative dynamics of large vortex arrays in trapped Bose-condensed gases. We show that in a static trap the interaction of the vortex array with thermal excitations leads to a non-exponential decay of the vortex structure, and the characteristic lifetime depends on the initial density of vortices. Drawing an analogy with physics of

B. Klein, J. J. M. Verbaarschot

We investigate the universality of microscopic eigenvalue correlations for Random Matrix Theories with the global symmetries of the QCD partition function. In this article we analyze the case of real valued chiral Random Matrix Theories ($β=1$) by relating the kernel of the correlations functions for $β=1$ to the kernel of chiral Random Matrix Theories with

G. Mauro D&#39;Ariano, Matteo G. A. Paris, Massimiliano F. Sacchi

We address several estimation problems in quantum optics by means of the maximum-likelihood principle. We consider Gaussian state estimation and the determination of the coupling parameters of quadratic Hamiltonians. Moreover, we analyze different schemes of phase-shift estimation. Finally, the absolute estimation of the quantum efficiency of both linear and

Ernst Karl Kunst

The modified Lorentz transformation of a distance-dependent special theory of relativity - which will be briefly summarized - predicts the possibility of superluminal velocity of very distantly moving material bodies to be connected with the generation of Cerencov radiation off the quantum vacuum. It is shown that vacuum Cerencov radiation due to the superlu

Mala Das, B. Roy, B. K. Chatterjee, S. C. Roy

Neutron detection efficiency of superheated drops of Freon22 for neutrons obtained from a 3Ci Am-Be neutron source has been reported in this paper. Neutron detection efficiency of both F-22 and F-12 have been determined from the measured nucleation rate using the volumetric method developed in our lab. The result shows that the neutron detection efficiency o

Mala Das, B. K. Chatterjee, B. Roy, S. C. Roy

Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquids are being utilised to develope the neutron spectromer. A new principle of neu

Ph. Bernard, G. Gemme, R. Parodi, E. Picasso

In this technical note the rf control and detection system for a detector of small harmonic displacements based on two coupled microwave cavities (PACO) is presented. The basic idea underlying this detector is the principle of parametric power conversion between two resonant modes of the system, stimulated by the (small) harmonic modulation of one system par

Xinwei Kong, Finn Ravndal

The rate for the fusion process $p + p \ra d + e^+ + ν_e$ is calculated using non-relativistic effective field theory. Including the four-nucleon derivative interaction, results are obtained in next-to-leading order in the momentum expansion. This reproduces the effects of the effective range parameter. Coulomb interactions between the incoming protons are i

W. Satula, R. Wyss

A mean-field model with a generalized pairing interaction that accounts for neutron-proton pairing is presented. Both the BCS as well as number-projected solutions of the model are presented. For the latter case the Lipkin-Nogami projection technique was extended to encompass the case of non-separable proton-neutron systems. The influence of the projection o

P. Moskal, H. -H. Adam, J. T. Balewski, A. Budzanowski

We describe a novel technique for comparing total cross sections for the reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta&#39; close to threshold. The initial and final state proton-proton interactions are factored out of the total cross section, and the dependence of this reduced cross section on the volume of phase space is discussed. Different

V. M. Eguiluz, E. Hernandez-Garcia, O. Piro

In the framework of spatially extended dynamical systems, we present three examples in which the presence of walls lead to dynamic behavior qualitatively different from the one obtained in an infinite domain or under periodic boundary conditions. For a nonlinear reaction-diffusion model we obtain boundary-induced spatially chaotic configurations. Nontrivial

Jean-Pierre Eckmann, Guido Schneider

We consider front solutions of the Swift-Hohenberg equation $\partial_t u= -(1+\partial_x^2)^2 u +ε^2 u -u^3$. These are traveling waves which leave in their wake a periodic pattern in the laboratory frame. Using renormalization techniques and a decomposition into Bloch waves, we show the non-linear stability of these solutions. It turns out that this proble

Jean-Pierre Eckmann, Guido Schneider

We consider the Taylor-Couette problem in an infinitely extended cylindrical domain. There exist modulated front solutions which describe the spreading of the stable Taylor vortices into the region of the unstable Couette flow. These transient solutions have the form of a front-like envelope advancing in the laboratory frame and leaving behind the stationary

Russell K. Standish

At Alife VI, Mark Bedau proposed some evolutionary statistics as a means of classifying different evolutionary systems. Ecolab, whilst not an artificial life system, is a model of an evolving ecology that has advantages of mathematical tractability and computational simplicity. The Bedau statistics are well defined for Ecolab, and this paper reports statisti

Nobuyuki Kakimi

We generalize the result of Kawamata concerning the strong version of Fujita&#39;s freeness conjecture for smooth 3-folds to some singular cases, namely, Gorenstein terminal singularities and quotient singularities of type 1/r(1,1,1) and of type 1/r(1,1,-1). We generalize furthermore the result of that to projective threefolds with only canonical singulariti

Yevgenia Kashina

In this paper we completely classify nontrivial semisimple Hopf algebras of dimension 16. We also compute all the possible structures of the Grothendieck ring of semisimple non-commutative Hopf algebras of dimension 16. Moreover, we prove that non-commutative semisimple Hopf algebras of dimension p^n, p is prime, cannot have a cyclic group of grouplikes.

Vladimir Retakh, Christophe Reutenauer, Arkady Vaintrob

In [2] M. Farber constructed invariants of m-component boundary links with values in algebra of noncommutative rational functions. In this paper we simplify his constructions and express them by using noncommutative generalizations of determinants introduced by Gelfand and Retakh. In particular, for every finite-dimensional module N over the algebra of nonco

Xiaotao Sun

We proved the factorization of generalized theta functions when the curve has two irreducible components meeting at one node.

Andrew Kresch

We describe the quantum cohomology rings of a class of toric varieties. The description includes, in addition to the (already known) ring presentations, the (new) analogues for toric varieties of the sorts of quantum Giambelli formulas which exist already for Grassmannian varieties, flag varieties, etc.

T. L. Boyadjiev, M. D. Todorov, P. P. Fiziev, S. S. Yazadjiev

We investigate numerically a models of the static spherically symmetric boson-fermion stars in scalar-tensor theory of gravity with massive dilaton field. The proper mathematical model of such stars is interpreted as a nonlinear two-parametric eigenvalue problem with unknown internal boundary. We employ the Continuous Analogue of Newton Method (CANM) which l

George E. Andrews, Christian Krattenthaler, Luigi Orsina, Paolo Papi

We study the combinatorics of ad-nilpotent ideals of a Borel subalgebra of $sl(n+1,\Bbb C)$. We provide an inductive method for calculating the class of nilpotence of these ideals and formulas for the number of ideals having a given class of nilpotence. We study the relationships between these results and the combinatorics of Dyck paths, based upon a remarka

Ioannis Gasparis

A family is constructed of cardinality equal to the continuum, whose members are totally incomparable, reflexive, hereditarily indecomposable Banach spaces.

Ken Dykema, Uffe Haagerup

We show that Voiculescu&#39;s circular operator and, more generally, each circular free Poisson operator has a continuous family of invariant subspaces relative to the von Neumann algebra it generates. The proof relies on upper triangular random matrix models and consequent realizations of these operators as upper triangular matrices of free random variables

Jean-Pierre Demailly, Lawrence Ein, Robert Lazarsfeld

Given an effective Q-divisor D on a smooth complex variety, one can associate to D its multiplier ideal sheaf J(D), which measures in a somewhat subtle way the singularities of D. Because of their strong vanishing properties, these ideals have come to play an increasingly important role in higher dimensional geometry. We prove that for two effective Q-diviso

A. A. Glutsuk

At the end of 1960-ths Yu.S.Ilyashenko stated the problem: is it true that for any one-dimensional holomorphic foliation with singularities on a Stein manifold leaves intersecting a transversal disc can be uniformized so that the uniformization function would depend holomorphically on the transversal parameter? In the present paper we construct a two-dimensi

Horace Stoica, S. -H. Henry Tye, Ira Wasserman

The cosmology of the Randall-Sundrum scenario for a positive tension brane in a 5-D Universe with localized gravity has been studied extensively recently. Here we extend it to more general situations. We consider the time-dependent situation where the two sides of the brane are different AdS/Schwarzschild spaces. We show that the expansion rate in these mode

Horatiu Nastase, Diana Vaman

We give arguments for a conjecture made in a previous paper, that one has to use only the gauged sugra action for the calculation of correlators of certain operators via the AdS-CFT correspondence. The existence of consistent truncations implies that the massive modes decouple, and gauged supergravity is sufficient for computing n-point functions of CFT oper

A. Chenaghlou

The one loop quantum corrections to the classical reflection factor of the sinh-Gordon model are calculated partially for general boundary conditions. The model is studied under boundary conditions which are compatible with integrability, and in the framework of the conventional perturbation theory generalized to the affine Toda field theory. It is found tha

Kei-Ichi Kondo

We give a new criterion of quark confinement/deconfinement by deriving a low-energy effective theory of QCD. The effective theory can explain Abelian dominance in low-energy physics of QCD, especially, quark confinement. Finally, we apply the above criterion to the large flavor QCD and discuss its phase structure. The result suggests the existence of conform

G. C. Branco, M. N. Rebelo, J. I. Silva-Marcos

We study the exactly degenerate case for three lefthanded Majorana neutrinos building a general parametrization for the leptonic mixing matrix characterized by two angles and one CP violating phase and identify a weak-basis invariant relevant, in this case, for CP violation. After lifting the degeneracy, this parametrization accommodates the present data on

Ali Abbasabadi, Wayne W. Repko

The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the t

J. A. Casas, J. R. Espinosa, A. Ibarra, I. Navarro

The approximate unification of gauge couplings is the best indirect evidence for low-energy supersymmetry, although it is not perfect in its simplest realizations. Given the experimental evidence for small non-zero neutrino masses, it is plausible to extend the MSSM with three right-handed neutrino chiral multiplets, with large Majorana masses below the unif

C. Q. Geng, C. C. Lih, C. C. Liu

We study the CP conserving and violating contributions to the decay of $\knng$ in the standard model. In our analysis, we use the form factors for $K\toγ$ transitions calculated directly in the entire physical range of momentum transfer within the light front model. We find that the branching ratios for the CP conserving and violating parts are about $1.0\ti

J. T. Peltoniemi, V. Sipilainen

We study the oscillations and conversions of relativistic neutrinos propagating in matter of variable density using the wave packet formalism. We show how the oscillation and coherence lengths are modified in comparison with the case of oscillations in vacuum. Secondly, we demonstrate how the equation of motion for two neutrino flavors can be formally solved

V. A. Mitsou

Due to the high energy and luminosity of the LHC, the ATLAS experiment has a huge discovery potential for new physics. A Standard Model Higgs boson can be discovered over the full range of allowed masses, and its mass should be measured with a precision of about 0.1%. The Higgs sector of the MSSM should be fully explored by searches for supersymmetric Higgs

G. Barenboim, F. Scheck

Charged tau leptons emerging in a long baseline experiment with a muon storage ring and a far-away detector will positively establish neutrino oscillations. We study the conversion of $ν_μ$ ($\barν_μ$) and of $\barν_e$ ($ν_e$) to $ν_τ$ or $\barν_τ$ for neutrinos from a 20 GeV muon storage ring, within the strong mixing scheme and on the basis of the squared

D. Boyanovsky, H. J. de Vega, M. Simionato

Critical slowing down of the relaxation of the order parameter is relevant both in early the universe and in ultrarelativistic heavy ion collisions. We study the relaxation rate of the order parameter in an O(N) scalar theory near the critical point to model the non-equilibrium dynamics of critical fluctuations near the chiral phase transition.A lowest order

S. A. Fayans, L. A. Mikaelyan, V. V. Sinev

Neutrino scattering on electrons is considered as a tool for laboratory searches of the neutrino magnetic moment. We study inelastic $\barν_ee^-$-scattering on electrons bound in the germanium (Z=32) and iodine (Z=53) atoms for antineutrinos generated in a nuclear reactor core and also in the $^{90}$Sr-$^{90}$Y and $^{147}$Pm artificial sources. Using the re

X. -J. Wang, M. -L. Yan

We study light (current) quark masses in framework of chiral constitutent quark model. In our calculation the current quark masses are defined uniquely, and all order effects of the light quark masses are considered. The results at energy scale $μ=m_ρ$ are $m_s=(160\pm 15)$MeV, $m_s/m_d=20.2\pm 3.0$, $m_u/m_d=0.5\pm 0.09$.

R. Delbourgo, Dongsheng Liu

The decays of a scalar particle, of either parity, into two photons or into two gravitons are evaluated. The effective interactions are of the form $ϕFF, ϕF\tilde{F}$ or $ϕRR,ϕR\tilde{R}$; in particular, Higgs boson decay into gravitons cannot be adduced to an interaction $ϕR$, as has been recently claimed.

G. Cvetic, S. K. Kang, C. S. Kim, K. Lee

Tilted brane in theories with large compact extra dimensions leads to spontaneous symmetry breaking of the Lorentz and rotational invariance in four dimensions, as shown by Dvali and Shifman. In this brief report, we point out that the mentioned Lorentz symmetry breaking, although leading to the CPT--violating interaction terms, cannot lead to the CPT violat

G. Rajasekaran

The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

S. Nussinov, R. D. Peccei, X. M. Zhang

Simple &#34;unitarity inspired&#34; relations between two- and three-body lepton flavor violating decays are noted and discussed. In the absence of cancellations, the existing strong bounds on $μ\to 3e$ and $ μ\to eγγ$ severly constrain two-body lepton flavor violating decays.

M. M. Islam

A model of $pp$ and $\bar{p}p$ elastic scattering developed previously to analyze ISR and SPS Collider data is extended to predict $pp$ elastic differential cross section at LHC at c.m. energy of 14 TeV and momentum transfer range $|t|=0$ - 10 GeV$^2$. Role of the gauged linear $σ$-model as an underlying field theory model describing nucleon structure and el

Reinhard Alkofer, Lorenz von Smekal

Some features of the solutions to the truncated Dyson-Schwinger equations(DSEs) for the propagators of QCD in Landau gauge are summarized. In particular, the Kugo-Ojima confinement criterion is realized, and positivity of transverse gluons is manifestly violated in these solutions. In Landau gauge, the gluon-ghost vertex function offers a convenient possibil

D. B. Cline

The scalar sector of the electroweak theory can be probed by a mu^+mu^- collider S channel resonance machine. We give arguments for when such a machine may be needed and when this information could be obtained by the LHC detector. A very interesting case is the possibility that several scalar particles are in the same mass range for the supersymmetric Higgs

M. Cataldo, S. del Campo

We show in this comment that in an anisotropic Bianchi type I model of the Kasner form, it is not possible to describe the growth of entropy, if we want to keep the thermodynamics together with the dominant energy conditions. This consequence disagrees with the results obtained by Brevik and Pettersen [Phys. Rev. D 56, 3322 (1997)].

S. Cotsakis, V. R. Gavrilov, V. N. Melnikov

A classical model of gravity theory with several dilatonic scalar fields and differential forms admitting an interpretation in terms of intersecting p-branes is studied in (pseudo)-Riemannian space-time $M =R_+\times S^{d_0}\times R_t\times M_2^{d_2}...\times M_n^{d_n}$ of dimension D. The equations of motion of the model are reduced to the Euler-Lagrange eq

Michael C. Ashworth Sean A. Hayward

We calculate the Noether currents and charges for Einstein-Maxwell theory using a version of the Wald approach. In spherical symmetry, the choice of time can be taken as the Kodama vector. For the static case, the resulting combined Einstein-Maxwell charge is just the mass of the black hole. Using either a classically defined entropy or the Iyer-Wald selecti

Eric Breck, John D. Burger, Lisa Ferro, Lynette Hirschman

In this paper, we report on Qaviar, an experimental automated evaluation system for question answering applications. The goal of our research was to find an automatically calculated measure that correlates well with human judges&#39; assessment of answer correctness in the context of question answering tasks. Qaviar judges the response by computing recall ag

Markus Frick, Martin Grohe

We introduce the concept of a class of graphs, or more generally, relational structures, being locally tree-decomposable. There are numerous examples of locally tree-decomposable classes, among them the class of planar graphs and all classes of bounded valence or of bounded tree-width. We also consider a slightly more general concept of a class of structures

F. Ferrucci, G. Pacini, M. I. Sessa

In (Ferrucci, Pacini and Sessa, 1995) an extended form of resolution, called Reduced SLD resolution (RSLD), is introduced. In essence, an RSLD derivation is an SLD derivation such that redundancy elimination from resolvents is performed after each rewriting step. It is intuitive that redundancy elimination may have positive effects on derivation process. How

F. von Oppen, D. Ullmo, H. U. Baranger

We consider the contribution of electron-electron interactions to the orbital magnetization of a two-dimensional electron gas, focusing on the ballistic limit in the regime of negligible Landau-level spacing. This regime can be described by combining diagrammatic perturbation theory with semiclassical techniques. At sufficiently low temperatures, the interac

Girish S. Setlur

Here we write down and prove closed commutation rules for Fermi bilinears in a two-component Fermi system in terms of the relevant sea-bosons. We show how the commutation rules come out correctly within the RPA-approximation as do the zero temperature correlation functions. We write down hamiltonains of nonrelativistic interacting electron-hole systems and p

Lincoln D. Carr, Mary Ann Leung, William P. Reinhardt

It is shown that the quasi-one-dimensional Bose-Einstein condensate is experimentally accessible and rich in intriguing phenomena. We demonstrate numerically and analytically the existence, stability, and perturbation-induced dynamics of all types of stationary states of the quasi-one-dimensional nonlinear Schrodinger equation for both repulsive and attracti

Ekkehard Krüger

The superconductor niobium possesses a narrow, roughly half-filled energy band with Bloch functions which can be unitarily transformed into optimally localized spin-dependent Wannier functions belonging to a double-valued representation of the space group of Nb. The special symmetry of this &#34;superconducting band&#34; can be interpreted within a nonadiaba

R. Haeussler, E. Scheer, H. B. Weber, H. v. Loehneysen

The phase of Aharonov-Bohm oscillations in mesoscopic metal rings in the presence of a magnetic field can be modulated by application of a DC-bias current I_DC. We address the question of how a variation of I_DC and hence of the microscopic phases of the electronic wave functions results in the macroscopic phase of the conductance oscillations. Whereas the f

F. Corberi, G. Gonnella, D. Suppa

Steady-state properties of microemulsions in shear flow are studied in the context of a Ginzburg-Landau free-energy approach. Explicit expressions are given for the structure factor and the time correlation function at the one loop level of approximation. Our results predict a four-peak pattern for the structure factor, implying the simultaneous presence of