August 2001 arXiv papers — page 20

D. Debruyne, J. Ryckebusch, S. Janssen, T. Van Cauteren

We outline a relativistic and unfactorized framework to treat the final-state interactions in quasi-elastic A(e,e'p) reactions for four-momentum transfers Q$^{2} \gtrsim 0.3$ (GeV/c)$^{2}$. The model, which relies on the eikonal approximation, can be used in combination with optical potentials, as well as with the Glauber multiple-scattering method. We a

Luis Bento, Zurab Berezhiani

We propose a new mechanism to block the active-sterile neutrino oscillations in the Early Universe. We show that a typical consequence of theories where the lepton number is spontaneously broken is the existence of a coherent cosmological Majoron field with a strength proportional to the lepton and baryon numbers of the Universe. This field interacts with le

A. Acin

We study the relation between violation of Bell inequalities and distillability properties of quantum states. Recently, Dür has shown that there are some multiparticle bound entangled states, non-separable and non-distillable, that violate a Bell inequality. We prove that for all the states violating this inequality there exist at least one splitting of the

L. L. Sanchez-Soto, J. J. Monzon, T. Yonte, J. F. Carinena

The action of any lossless multilayer is described by a transfer matrix that can be factorized in terms of three basic matrices. We introduce a simple trace criterion that classifies multilayers in three classes with properties closely related with one (and only one) of these three basic matrices.

Ivo Haering, Jan M Rost

Elastic scattering probes directly the interaction potential. For weakly interacting condensates this potential is given by the condensate density. We investigate how the differential and total cross sections reflect the density. In particular, we have determined which signatures the Thomas Fermi approximation leaves in contrast to an exact solution for the

G. A. Kouzaev

In the paper an approach is presented allowing to model quantum logic circuits by electronic gates for discrete spatially modulated electromagnetic signals. The designed circuitry is for modeling low scale quantum nets of general design and quantum devices based only on superposition principle of their work.

C. Figueira de Morisson Faria, R. Kopold, W. Becker, J. M. Rost

Solving the one-dimensional time-dependent Schrödinger equation for simple model potentials, we investigate resonance-enhanced high-order harmonic generation, with emphasis on the physical mechanism of the enhancement. By truncating a long-range potential, we investigate the significance of the long-range tail, the Rydberg series, and the existence of highly

Gerald L. Fitzpatrick

Assuming that the e- and (mu- or tau-type) neutrinos start and end "life" as topologically distinct quantum objects, and assuming that topology maintenance is preferred over topology change, both the matrix describing long-distance neutrino mixtures, and certain neutrino mixing parameters are derived (assuming that CP-violation is not maximal). Predi

John Michael Williams

The data supporting neutrino oscillations are reexamined empirically, ignoring the phase space of the usual theory. An absolutely minimum description can be constructed easily without assuming oscillations. An empirical fit to a simplified but representative set of neutrino problem data may require only two free parameters; the usual oscillation theory requi

Gerhard Baur, Kai Hencken, Dirk Trautmann

As a model of a neutron halo nucleus we consider a neutron bound to an inert core by a zero range force. We study the breakup of this simple nucleus in the Coulomb field of a target nucleus. In the post-form DWBA (or, in our simple model CWBA (``Coulomb Wave Born Approximation'')) an analytic solution for the T-matrix is known. We study limiting case

A. R. Its, A. A. Kapaev

Using the Riemann-Hilbert approach, we study the quasi-linear Stokes phenomenon for the second Painlevé equation $y_{xx}=2y^3+xy-α$. The precise description of the exponentially small jump in the dominant solution approaching $α/x$ as $|x|\to\infty$ is given. For the asymptotic power expansion of the dominant solution, the coefficient asymptotics is found.

Piero Cipriani, Maria Teresa Di Bari

Using the tools of Differential Geometry, we define a new <<fast>> chaoticity indicator, able to detect dynamical instability of trajectories much more effectively, (i.e. &#34;quickly&#34;) than the usual tools, like Lyapunov Characteristic Numbers (LCN&#39;s) or Poincare` Surface of Section. Moreover, at variance with other &#34;fast&#34; indicators propose

Sarah-Marie Belcastro

Using toric geometry, lattice theory, and elliptic surface techniques, we compute the Picard Lattice of certain K3 surfaces. In particular, we examine the generic member of each of M. Reid&#39;s list of 95 families of Gorenstein K3 surfaces which occur as hypersurfaces in weighted projective 3-spaces. The results appear in a multipage table near the end of t

Johannes Sjoestrand, Maciej Zworski

Trace formulae provide one of the most elegant descriptions of the classical-quantum correspondence. One side of a formula is given by a trace of a quantum object, typically derived from a quantum Hamiltonian, and the other side is described in terms of closed orbits of the corresponding classical Hamiltonian. In algebraic situations, such as the original Se

C. Azizieh

We extend to the case of a system involving p-Laplacians, the monotonicity and symmetry results of Damascelli and Pacella obtained in the case of a scalar p-Laplace equation with $1<p<2$. For this purpose, we use the moving hyperplanes method and we suppose that the right hand sides are increasing and locally Lipschitz continuous.

Takeshi Katsura

We completely determine the ideal structures of the crossed products of Cuntz algebras by quasi-free actions of abelian groups and give another proof of A. Kishimoto&#39;s result on the simplicity of such crossed products. We also give a necessary and sufficient condition that our algebras become primitive, and compute the Connes spectra and K-groups of our

Jose M. F. Labastida, Marcos Marino

Recent progress in string theory has led to a reformulation of quantum-group polynomial invariants for knots and links into new polynomial invariants whose coefficients can be understood in topological terms. We describe in detail how to construct the new polynomials and we conjecture their general structure. This leads to new conjectures on the algebraic st

Yuri I. Manin, Matilde Marcolli

Using techniques introduced by D. Mayer, we prove an extension of the classical Gauss-Kuzmin theorem about the distribution of continued fractions, which in particular allows one to take into account some congruence properties of successive convergents. This result has an application to the Mixmaster Universe model in general relativity. We then study some a

Krzysztof Gawedzki

We extend the analysis of the canonical structure of the Wess-Zumino-Witten theory to the bulk and boundary coset G/H models. The phase spaces of the coset theories in the closed and in the open geometry appear to coincide with those of a double Chern-Simons theory on two different 3-manifolds. In particular, we obtain an explicit description of the canonica

Maja Buric, Marija Dimitrijevic, Voja Radovanovic

The one-loop quantum corrections for BTZ black hole are considered using the dimensionally reduced 2D model. Cases of 3D minimal and conformal coupling are analyzed. Two cases are considered: minimally coupled and conformally coupled 3D scalar matter. In the minimal case, the Hartle-Hawking and Unruh vacuum states are defined and the corresponding semiclassi

Martin Schaden

The local action of an SU(2) gauge theory in general covariant Abelian gauges and the associated equivariant BRST symmetry that guarantees the perturbative renormalizability of the model are given. A global SL(2,R) symmetry of the model is spontaneously broken by ghost-antighost condensation at arbitrarily small coupling. This leads to propagators that are f

S. Q. Wu, X. Cai

It is shown that Hawking radiation of Dirac particles does not exist for $P_1, Q_2$ components but for $P_2, Q_1$ components in a charged Vaidya - de Sitter black hole. Both the location and the temperature of the event horizon change with time. The thermal radiation spectrum of Dirac particles is the same as that of Klein-Gordon particles. Our result demons

Y. Hoshino

The Gauge Technique has been applied to QED$_{2+1}$ in the quenched case with infrared subtraction. The behaviour of the fermion propagator near the threshold is then found to be \[ S(p)\to \frac{(γ\cdot p+m)}{(p^{2}-m^{2})}(\frac{p^{2}-m^{2}}{% 2m^{2}})^ζ\exp (-\frac{ης}{2}), \] where $ς=e^{2}/(4πm)$ and this is gauge invariant except the exponential factor

Nathan F. Lepora

This manuscript has been withdrawn by the author. Some of the material has been included in the manuscript &#39;Embedded Monopoles&#39; at hep-th/0106254.

Michelangelo L. Mangano, Mauro Moretti, Roberto Pittau

We study in this paper the production, in hadronic collisions, of final states with W gauge bosons, heavy quark pairs and n extra jets (with n up to 4). The complete partonic tree-level QCD matrix elements are evaluated using the ALPHA algorithm, and the events generated at the parton level are then evolved through the QCD shower and eventually hadronised us

E. Lunghi

The recently reported measurements of the CP asymmetry a(psi K) by the BABAR and BELLE collaborations are in good agreement with the standard model prediction. With the anticipated precision in a(psi K) at the B factories and hadron colliders, one hopes to pin down any possible deviation from the SM. We discuss an extension of the MFV-supersymmetric models w

Nathan F. Lepora

This has been withdrawn by the author. A rewrite of some of the material is currently in progress.

Nathan F. Lepora

This manuscript has been withdrawn by the author. Some of the material has been included in the manuscript &#39;Dualizing the Dual Standard Model&#39; hep-ph/0102084.

Silvia Necco, Rainer Sommer

We study the potential of a static quark anti-quark pair in the range 0.05fm \leq r \leq 0.8fm, employing a sequence of lattices up to 64^4. Lattice artifacts in potential and force are investigated theoretically as well as numerically and continuum quantities are obtained by extrapolation of the results at finite lattice spacing. Consistency of the numerica

V. Buescher

Recent results of searches for new phenomena using data collected in Run I by the CDF and D0 experiments are presented. D0 set limits for top squarks decaying into b+l+sneutrino significantly beyond the reach of previous analyses in this channel (m_stop>140GeV at 95% C.L. for m_snu=45GeV). CDF exclude top squarks decaying into b+tau for masses below 111GeV.

Bob Olivier

We report a search for large extra spatial dimensions in $p\bar{p}$ collisions at a center of mass energy of 1.8 TeV at the Tevatron. We present recent D0 results on graviton-mediated exchange processes, using events containing a pair of electrons or photons. No evidence for signal is found, allowing to place the most restrictive lower limits on the effectiv

S. Ahmed

We present the first measurement of the D*+ width using 9/fb of e+e- data collected near the Upsilon(4S) resonance by the CLEO II.V detector. Our method uses advanced tracking techniques and a reconstruction method that takes advantage of the small vertical size of the CESR beam spot to measure the energy release distribution from the D*+ -> D0 pi+ decay. We

B. Badelek, C. Blochinger, J. Blumlein, E. Boos

TESLA Technical Design Report, Part VI, Chapter 1: The Photon Collider at TESLA

S. Q. Wu, X. Cai

Hawking evaporation of Dirac particles and scalar fields in a Vaidya-type black hole is investigated by the method of generalized tortoise coordinate transformation. It is shown that Hawking radiation of Dirac particles does not exist for $P_1, Q_2$ components but for $P_2, Q_1$ components in any Vaidya-type black holes. Both the location and the temperature

Scott M. Hitchcock

What are the implications if the total &#39;information&#39; in the universe is conserved? Black holes might be &#39;logic gates&#39; recomputing the &#39;lost information&#39; from incoming &#39;signals&#39; from outside their event horizons into outgoing &#39;signals&#39; representing evaporative or radiative decay &#39;products&#39; of the reconfiguration

S. S. Gershtein, A. A. Logunov, M. A. Mestvirishvili

It is shown that the RTG predicts an opportunity of the intensive production of gravitons at the early stage of evolution of the homogeneous isotropic Universe. A hypothesis is suggested that the produced gas of gravitons could be just the ``dark matter&#39;&#39; which presently manifests itself as a ``missing mass&#39;&#39; in our Universe.

Naren Ramakrishnan, Saverio Perugini

Information personalization refers to the automatic adjustment of information content, structure, and presentation tailored to an individual user. By reducing information overload and customizing information access, personalization systems have emerged as an important segment of the Internet economy. This paper presents a systematic modeling methodology - PI

M. I. Dykman, Brage Golding

The rates of activated processes, such as escape from a metastable state and nucleation, are exponentially sensitive to an externally applied field. We describe how this applies to modulation by high-frequency fields and illustrate it with experimental observations. The results may lead to selective control of diffusion in periodic potentials, novel control

I. V. Pylyuk, M. P. Kozlovskii

The 3D one-component spin system in an external magnetic field is studied using the collective variables method. The integration of the partition function of the system over the phase space layers is performed in the approximation of the sextic measure density including the even and the odd powers of the variable (the asymmetric $ρ^6$ model). The general rec

Jordan M. Gerton, Brian J. Frew, Randall G. Hulet

We observe a light-induced frequency shift in single-photon photoassociative spectra of magnetically trapped, quantum degenerate 7Li. The shift is a manifestation of the coupling between the threshold continuum scattering states and discrete bound levels in the excited-state molecular potential induced by the photoassociation laser. The frequency shift is ob

D. Belitz, S. L. Sessions, T. R. Kirkpatrick, M. T. Mercaldo

The behavior of the conductivity and the density of states, as well as the phase relaxation time, of disordered itinerant electrons across a quantum ferromagnetic transition is discussed. It is shown that critical fluctuations lead to anomalies in the temperature and energy dependence of the conductivity and the tunneling density of states, respectively, tha

F. S. Cataliotti, S. Burger, C. Fort, P. Maddaloni

We report on the direct observation of an oscillating atomic current in a one-dimensional array of Josephson junctions realized with an atomic Bose-Einstein condensate. The array is created by a laser standing-wave, with the condensates trapped in the valleys of the periodic potential and weakly coupled by the inter-well barriers. The coherence of multiple t

Yasha Gindikin, V. A. Sablikov

The dynamic density response function, form-factor, and spectral function of a Luttinger liquid with Coulomb electron-electron interaction are studied with the emphasis on the short-range electron correlations. The Coulomb interaction changes dramatically the density response function as compared to the case of the short-ranged interaction. The form of the d

Yehuda B. Band, Boris Malomed, Marek Trippenbach

A simple model of an atomic Bose-Einstein condensate in a box whose size varies with time is studied to determine the nature of adiabaticity in the nonlinear dynamics obtained within the Gross-Pitaevskii equation (the nonlinear Schrödinger equation). Analytical and numerical methods are used to determine the nature of adiabaticity in this nonlinear quantum s

Stellan Ostlund, Martin Andersson

In a tight binding model of charged spin-1/2 electrons on a square lattice, a fully polarized ferromagnetic spin configuration generates an apparent U(1) flux given by $2π$ times the skyrmion charge density of the ferromagnetic order parameter. We show here that for an antiferromagnet, there are two ``fictitious&#39;&#39; magnetic fields, one staggered and o

P. A. Bruhwiler, P. Baltzer, S. Andersson, D. Arvanitis

We report temperature-dependent photoelectron spectra for a monolayer of C_60 adsorbed on HOPG, as well as C 1s x-ray absorption. This extends a previous report which showed the close similarity between the spectrum of the HOMO for the two-dimensional overlayer and that of C_60 in the gas phase. The present work shows that intermolecular and molecule-substra

Igor Travenec, Peter Markos

We study numerically the metal - insulator transition in the Anderson model on various lattices with dimension $2 < d \le 4$ (bifractals and Euclidian lattices). The critical exponent $ν$ and the critical conductance distribution are calculated. We confirm that $ν$ depends only on the {\it spectral} dimension. The other parameters - critical disorder, critic

Th. Koschny, L. Schweitzer

The disorder driven quantum Hall to insulator transition is investigated for a two-dimensional lattice system. We consider a Gaussian correlated random potential, study the behaviour of the current carrying states and trace their energetical position when the disorder strength is increased. Our results qualitatively resemble those obtained previously for exp

K. Pan, S. R. Federman, D. E. Welty

We present high-resolution observations of interstellar CN, CH, CH^{+}, \ion{Ca}{1}, and \ion{Ca}{2} absorption lines toward the multiple star systems HD206267 and HD217035. Substantial variations in CN absorption are observed among three sight lines of HD206267, which are separated by distances of order 10,000 AU; smaller differences are seen for CH, CH^{+}

M. M. Briley, G. H. Smith, C. F. Claver

We present V, B-V, and DDO C(41-42) and C(42-45) photometry for a sample of 75 red giants down to M_V = +2 in the relatively metal-rich Galactic globular cluster M71. The C(41-42) colors reveal a bimodal distribution of CN band strengths generally anticorrelated with CH band strength as measured by the C(42-45) color. Both DDO colors agree well with those fo

M. Revnivtsev, R. Sunyaev

We present the analysis of the Chandra image of KS 1731-260. The improvement of the source localization (down to ~0.6&#39;&#39;) allowed us to rule out 12 of 13 infrared companion candidates proposed by Barret et al. (1998). The remaining possible infrared counterpart of KS 1731-260 (angular distance between sources ~1.45&#39;&#39;, or ~2σ) has the brightnes

Brian Chaboyer, W. H. Fenton, Jenica E. Nelan, D. J. Patnaude

Stellar evolution models which include the effect of helium and heavy element diffusion have been calculated for initial iron abundances of [Fe/H] = -2.3, -2.1, -1.9 and -1.7. These models were calculated for a large variety of masses and three separate mixing lengths, α= 1.50, 1.75 and 2.00 (with α= 1.75 being the solar calibrated mixing length). The change

Gopal-Krishna, Paul J. Wiita

Evidence for extended active lifetimes (> 10^8 yr) for radio galaxies implies that many large radio lobes were produced during the `quasar era&#39;, 1.5 < z < 3, when the comoving density of radio sources was 2 -- 3 dex higher than the present level. However, inverse Compton losses against the intense microwave background substantially reduce the ages and nu

NVO Interim Steering Committee

The National Academy of Science Astronomy and Astrophysics Survey Committee, in its new Decadal survey entitled Astronomy and Astrophysics in the New Millennium, recommends, as a first priority, the establishment of a National Virtual Observatory. The NVO would link the archival data sets of space- and ground-based observatories, the catalogs of multi-wavele

C. Jones, W. Forman, A. Vikhlinin, M. Markevitch

Chandra images show symmetric, 8 kpc long, arm-like features in the X-ray halo surrounding NGC 4636. The leading edges of these features are sharp and are accompanied by temperature increases of ~30%. These properties, along with their scale and symmetry, suggest that the arm-like structures are produced by nuclear outburst driven shocks. We interpret these

Bohdan Paczynski

Variability in the sky has been known for centuries, even millennia, but our knowledge of it is very incomplete even at the bright end. Current technology makes it possible to built small, robotic optical instruments, to record images and to process data in real time, and to archive them on-line, all at a low cost. In addition to obtaining complete catalogs

John W. Keck, William W. Craig, Charles J. Hailey, Fiona Harrison

We present a long-term multi-wavelength light curve of Galactic black hole candidate GRS 1758-258 by combining previously published and archival data from GRANAT, ROSAT, CGRO, RXTE, SAX, ASCA, EXOSAT, and the VLA. In addition we include first spectral results from the balloon-borne Gamma-ray Arcminute Telescope Imaging System (GRATIS). In light of divergent

G. Ghisellini, A. Celotti

Relativistic jets carry a significant fraction of the total energy budget of a radio source, rivaling the power that is extracted through accretion. A minor part of this bulk kinetic power is transformed to radiation, possibly through internal shocks if the plasma is accelerated, at the base of the jet, to a velocity which changes in time. In this way we can

Katsuji Koyama

This paper reports on the early Chandra view of the Galactic center (GC) activities. The massive black hole Sgr A* is extremely faint, while more bright diffuse X-ray emission is prevailing in the circumnuclear disk. Another high temperature plasma is found in the Sgr A East shell. This may indicate that Sgr A East is a supernova remnant, although no clear X

R. Michael Rich

The dominant stellar population of the central bulge of the Milky Way is old, with roughly solar metallicity. The age is very similar to that of the old metal rich bulge globular clusters and to 47 Tucanae, which has an age of 13 Gyr. Stellar composition measurements from Keck/HIRES confirm that the bulge stars are enhanced in Mg and Ti. New HST/NICMOS data

R. I. Davies, D. Bonaccini, S. Rabien, W. Hackenberg

The Laser Guide Star Facility for the VLT will be commissioned during 2003. This, of course, can only be the first step towards enhancing the scientific output of the VLT through adaptive optics. So in this contribution we propose the development of a laser guide star multi-conjugate adaptive optics system. We consider geometries for the adaptive optics syst

Bram Boroson, Tim Kallman, Saeqa Dil Vrtilek

We present a unified picture of outflowing gas from the X-ray binary system Hercules X-1/HZ Herculis. We suggest that the outflowing gas (a wind) causes UV emission seen in mid-eclipse, narrow UV absorption lines, and broad UV P Cygni lines. Observations with the FOS and STIS spectrographs on the Hubble Space Telescope (HST) show UV emission lines in the mid

Michael S. Turner

A successor to the standard hot big-bang cosmology is emerging. It greatly extends the highly successful hot big-bang model. A key element of the New Standard Cosmology is dark energy, the causative agent for accelerated expansion. Dark energy is just possibly the most important problem in all of physics. The only laboratory up to the task of studying dark e

Adrienne M. Juett, Dimitrios Psaltis, Deepto Chakrabarty

There are three low-mass X-ray binaries (4U 0614+091, 2S 0918-549, and 4U 1543-624) for which broad line emission near 0.7 keV was previously reported. A recent high-resolution observation of 4U 0614+091 with the Chandra/LETGS found evidence for an unusually high Ne/O abundance ratio along the line of sight but failed to detect the previously reported 0.7 ke

Joop Schaye

Essentially all high-redshift galaxies show evidence for strong large-scale outflows that should have a profound effect on the structure and kinematics of both the galaxies themselves and their environment. The interstellar absorption spectra of both Lyman break galaxies (LBGs) and local starburst galaxies are remarkably similar to those of damped Ly-alpha (

Ehud Altman, Assa Auerbach

The strongly interacting Hubbard model on the square lattice is reduced to the low energy Plaquette Boson Fermion Model (PBFM). The four bosons (an antiferromagnon triplet and a d-wave hole pair), and the fermions are defined by the lowest plaquette eigenstates. We apply the Contractor Renormalization method of Morningstar and Weinstein to compute the boson

A. K. Dutt-Mazumder, C. Gale, A. Majumder, O. Teodorescu

We discuss two possible signatures of symmetry breaking that can appear in dilepton spectra, as measured in relativistic heavy ion collisions. The first involves scalar-vector meson mixing and is related to the breaking of Lorentz symmetry by a hot medium. The second is related to the breaking of Furry&#39;s theorem by a charged quark-gluon plasma. Those sig

Fiorenza Donato, David Maurin, Richard Taillet

In the present paper, we extend the analysis of Maurin et al. (2001) and Donato et al. (2001) to the $β$-radioactive nuclei $^{10}$Be, $^{26}$Al and $^{36}$Cl. These species are be shown to be particularly sensitive to the properties of the local interstellar medium (LISM). As studies of the LISM suggest that we live in an underdense bubble of extent $r_{hol

P. Faccioli, E. Shuryak

We report the first non-perturbative calculation of proton electro-magnetic form-factors in the Random Instanton Liquid Model (RILM) and in the Interacting Instanton Liquid Model (IILM). By calculating the ratio of appropriate three-point to two-point functions, we divide out the coupling constants and compare our results directly to some integral of the for

Bodo Geyer, Markus Lazar, Dieter Robaschik

A group theoretical procedure for parametrizing non-forward matrix elements of non-local QCD operators is introduced. The related (two-variable) distribution amplitudes are given as sum over power corrections of the double distributions. For totally symmetric (local) operators the infinite twist decomposition is given completely and for operators with non-tr

L. Albano, D. F. Mundarain, J. Stephany

We compute the photon number distribution, the Q distribution function and the wave functions in the momentum and position representation for a single mode squeezed number state using generating functions which allow to obtain any matrix element in the squeezed number state representation from the matrix elements in the squeezed coherent state representation

Robert H. Becker, Xiaohui Fan, Richard L. White, Michael A. Strauss

We present moderate resolution Keck spectroscopy of quasars at z=5.82, 5.99 and 6.28, discovered by the Sloan Digital Sky Survey (SDSS). We find that the Ly Alpha absorption in the spectra of these quasars evolves strongly with redshift. To z~5.7, the Ly Alpha absorption evolves as expected from an extrapolation from lower redshifts. However, in the highest

UKQCD Collaboration, A. Hart, M. Teper

We study the topological susceptibility, chi, in QCD with two quark flavours using lattice field configurations that have been produced with an O(a) improved quark action. We find clear evidence for the expected suppression at small quark mass, and examine the variation of chi with this mass. The resulting estimate of the pion decay constant, f_pi = 105 +/-

Robert Oeckl

The natural generalization of the notion of bundle in quantum geometry is that of bimodule. If the base space has quantum group symmetries one is particularly interested in bimodules covariant (equivariant) under these symmetries. Most attention has so far been focused on the case with maximal symmetry -- where the base space is a quantum group and the bimod

S. Heinemeyer

In the Minimal Supersymmetric Standard Model with complex parameters (cMSSM) we calculate higher order corrections to the Higgs boson sector in the Feynman-diagrammatic approach using the on-shell renormalization scheme. The application of this approach to the cMSSM, being complementary to existing approaches, is analyzed in detail. Numerical examples for th

D. Lacoste, P. J. Collings, T. C. Lubensky

This paper concerns optical properties of the isotropic phase above the isotropic-cholesteric transition and of the blue phase BP III. We introduce an effective index, which describes spatial dispersion effects such as optical rotation, circular dichroism, and the modification of the average index due to the fluctuations. We derive the wavelength dependance

Francesca Colaiori, M. A. Moore

We have studied the Kardar-Parisi-Zhang equation in the strong coupling regime in the mode-coupling approximation. We solved numerically in dimension d=1 for the correlation function at wavevector k. At large times t we found the predicted stretched exponential decay consistent with our previous saddle point analysis in [Phys. Rev. E {\bf 63}, 057103 (2001)]

Sortelano Araujo Diniz, Olivier Piguet

We show that the mass of the Fayet hypermultiplet, which represents the matter sector of N=2 supersymmetric Yang-Mills theory, may be induced through a generalization of the central charge constraint usually proposed in the literature. This mass showing up as a parameter of the supersymmetry transformations, we conclude that it will stay unrenormalized at th

Stefan Rombouts, Dimitri Van Neck, Karel Peirs, Lode Pollet

One of the major differences between fermions and bosons is that fermionic states have a maximum occupation number of one, whereas the occupation number for bosonic states is in principle unlimited. For bosons that are made up of fermions, one could ask the question to what extent the Pauli principle for the constituent fermions would limit the boson occupat

B. S. Skrzynski, I. S. Beloborodov, K. B. Efetov

We study the fluctuation conductivity of superconducting granular metals at low temperatures and strong magnetic field destroying the Cooper pairs. Explicit calculations are performed for larger values of the coupling between the grains than those considered in previous works. We show that in a broad region of the coupling constants the superconducting fluct

Keisuke Taniguchi, Eric Gourgoulhon

We study equilibrium sequences of close binary systems on circular orbits and composed of different mass stars with polytropic equation of state in Newtonian gravity. The solving method is a multidomain spectral method which we have recently developed. The computations are performed for both cases of synchronized and irrotational binary systems with adiabati

A. Bouda, T. Djama

In this paper, we apply the one dimensional quantum law of motion, that we recently formulated in the context of the trajectory representation of quantum mechanics, to the constant potential, the linear potential and the harmonic oscillator. In the classically allowed regions, we show that to each classical trajectory there is a family of quantum trajectorie

R. Kerner, A. L. Barbosa, D. V. Gal&#39;tsov

Classical version of Born-Infeld electrodynamics is recalled and its most important properties discussed. Then we analyze possible abelian and non-abelian generalizations of this theory, and show how certain soliton-like configurations can be obtained. The relationship with the Standard Model of electroweak interactions is also mentioned.

Amitava Datta, Abhijit Samanta

We study the effects of SO(10) D-terms on the allowed parameter space (APS) in models with $t - b - τ$ and $b - τ$ Yukawa unifiction. The former is allowed only for moderate values of the D-term, if very precise ($\le$ 5%) unification is required. Next we constrain the parameter space by looking for different dangerous directions where the scalar potential m

E. Christova, S. Kretzer, E. Leader

By combining recent HERMES data on semi-inclusive DIS $π^\pm$-production with the singlet fragmentation function $D_Σ^{π^+}$, which is well determined from $e^+e^-$ data, we are able to extract, for the first time, the flavoured fragmentation functions $D_u^{π^+}$, $D_d^{π^+}$ and $D_s^{π^+}$ without making any assumptions about favoured and unfavoured trans

R. Plaga

(abridged) The physical mechanisms that make a neutrino with standard-model (SM) weak interactions a &#34;lepton-number conservation (LNC) violating&#34; neutrino such as the Majorana neutrino are analysed in a basis of two Majorana states that have opposite charge-parity (&#34;charge-parity basis&#34;). A small Majorana mass that is larger than any Dirac ma

Guido Burkard, Daniel Loss

We study the effect of the spin-orbit interaction on quantum gate operations based on the spin exchange coupling where the qubit is represented by the electron spin in a quantum dot or a similar nanostructure. Our main result is the exact cancellation of the spin-orbit effects in the sequence producing the quantum XOR gate for the ideal case where the pulse

Monika Sinha, Mira Dey, Subharthi Ray, Jishnu Dey

X-ray bursts from compact stars is believed to be due to type I thermonuclear processes which are short lived, typically ~ 10 to 100 s. There are some low mass X-ray binaries (LMXB) like 4U 1820-30, 4U 1636-53, KS 1731-260 and Serpens X-1, known as Super Bursters (SB) which emit X-rays close to the Eddington luminosity limit for long periods of several hours

Yeong-Chuan Kao, Yu-Wen Lee

We study the Schwinger model on a half-line in this paper. In particular, we investigate the behavior of the chiral condensate near the edge of the line. The effect of the chosen boundary condition is emphasized. The extension to the finite temperature case is straightforward in our approach.

Masahiro Kawasaki, Takeo Moroi, Tomo Takahashi

We consider effects of the isocurvature perturbation in the framework of the tracker-type quintessence models. During the inflation, fluctuations in the amplitude of the quintessence field are generated, which provide isocurvature component of the cosmic density perturbation. Contrary to the conventional notion, it is shown that effects of the isocurvature f

G. P. Berman, F. Borgonovi, G. Chapline, S. A. Gurvitz

Single-spin detection is one of the important challenges facing the development of several new technologies, e.g. single-spin transistors and solid-state quantum computation. Magnetic resonance force microscopy with a cyclic adiabatic inversion, which utilizes a cantilever oscillations driven by a single spin, is a promising technique to solve this problem.

Miklos Redei, Stephen J. Summers

If \{A(V)\} is a net of local von Neumann algebras satisfying standard axioms of algebraic relativistic quantum field theory and V_1 and V_2 are spacelike separated spacetime regions, then the system (A(V_1),A(V_2),ϕ) is said to satisfy the Weak Reichenbach&#39;s Common Cause Principle iff for every pair of projections A \in A(V_1), B \in A(V_2) correlated i

Frank Verstraete, Koenraad Audenaert, Jeroen Dehaene, Bart De Moor

In this paper we investigate two different entanglement measures in the case of mixed states of two qubits. We prove that the negativity of a state can never exceed its concurrence and is always larger then $\sqrt{(1-C)^2+C^2}-(1-C)$ where $C$ is the concurrence of the state. Furthermore we derive an explicit expression for the states for which the upper or

Michael A. Nielsen

What resources are universal for quantum computation? In the standard model, a quantum computer consists of a sequence of unitary gates acting coherently on the qubits making up the computer. This paper shows that a very different model involving only projective measurements, quantum memory, and the ability to prepare the |0> state is also universal for quan

Thomas C. Bishop, Oleksandr O. Zhmudsky

A theoretical framework for evaluating the approximate energy and dynamic properties associated with the folding of DNA into nucleosomes and chromatin is presented. For this purpose experimentally determined elastic constants of linear DNA and a simple fold geometry are assumed to derive constants for the higher order folding. The model predicts the correct

A. I. Panin

New models of the Fock space sector corresponding to some fixed number of electrons are introduced. These models originate from the representability theory and their practical implementation may lead to essential reduction of dimensions of intermediate Configuration Interaction spaces. A certain zero-order theory that gives wave functions approximately equiv

N. Kaiser S. Fritsch, W. Weise

Using the two-loop approximation of chiral perturbation theory, we calculate the momentum and density dependent single particle potential of nucleons in isospin-symmetric nuclear matter. The contributions from one- and two-pion exchange diagrams give rise to a potential depth for a nucleon at rest of $U(0,k_{f0}) = -53.2 $MeV at saturation density. The momen

Yun Chang Shin, Myung Ki Cheoun, K. S. Kim, T. K. Choi

A role of the axial vector mesons, such as $K_1$ and $a_1$, on the emitted photon spectrum in hot hadronic matter is studied through the channels $πρ\to a_1 \to πγ$ and $K ρ\to K_1 \to K γ$. They are shown to be dominant channels in this spectrum. This study is carried out with an effective chiral lagrangian which includes vector and axial-vector mesons and

I. Chemakin, V. Cianciolo, B. A. Cole, R. C. Fernow

Differential cross-sections are presented for the inclusive production of charged pions in the momentum range 0.1 to 1.2 GeV/c in interactions of 12.3 and 17.5 GeV/c protons with Be, Cu, and Au targets. The measurements were made by Experiment 910 at the Alternating Gradient Synchrotron in Brookhaven National Laboratory. The cross-sections are presented as a

I. Scheuring, G. Karolyi, Z. Toroczkai, T. Tel

We investigate the effects of spatial heterogeneity on the coexistence of competing species in the case when the heterogeneity is dynamically generated by environmental flows with chaotic mixing properties. We show that one of the effects of chaotic advection on the passively advected species (such as phytoplankton, or self-replicating macromolecules) is the