June 1998 arXiv papers — page 10

Ivan Hubac, Peter Babinec, Martin Polasek, Jan Urban

The coupling of electronic and vibrational motion is studied by two canonical transformations namely normal coordinate transformation and momentum transformation on molecular Hamiltonian. It is shown that by these transformations we can pass from crude approximation to adiabatic approximation and then to non-adiabatic (diabatic) Hamiltonian. This leads to re

Dinesh K. Srivastava, Klaus Geiger

Multiple interactions of quarks and gluons in high-energy heavy-ion collisions may give rise to interesting phemomena of color charges propagating in high-density QCD matter. We study the dynamics of multi-parton systems produced in nucleus-nucleus collisions at energies corresponding the the CERN SPS and the future BNL RHIC experiments. Due to the complexit

D. Pelte, H. Merlitz

The conditions for the HBT interferometry from stars are compared to those encountered in heavy ion reactions. As a consequence the formalism using wavepackets is developed. The modifications relative to the standard formalism with plane waves are presented, and the effects of the residual Coulomb interactions between charged pions and with the charged sourc

Piotr Minc

A hereditarily indecomposable tree-like continuum without the fixed point property is constructed. The example answers a question of Knaster and Bellamy.

Ilia Zharkov

We consider regular Calabi-Yau hypersurfaces in $N$-dimensional smooth toric varieties. On such a hypersurface in the neighborhood of the large complex structure limit point we construct a fibration over a sphere $S^{N-1}$ whose generic fibers are tori $T^{N-1}$. Also for certain one-parameter families of such hypersurfaces we show that the monodromy transfo

J. Cruz

We show that a massive scalar field on a 2-dimensional Anti-De Sitter space can be mapped by means of a time-dependent canonical transformation into a massless free field theory when the mass square of the field is equal to minus the curvature of the background metric. We also provide the (hidden) conformal symmetry of the massive scalar field.

Peter Cho

We investigate the low energy structure of the Kahler potential in SUSY QCD with Nf=Nc+1 quark flavors. Since this theory's moduli space is everywhere smooth, a systematic power series expansion of its Kahler potential can be developed in terms of confined meson and baryon fields. Perturbation theory in the supersymmetric sigma model based upon a momentu

M. Cvetic, A. A. Tseytlin

Five-dimensional non-extreme rotating black holes with large NS-NS five-brane and fundamental string charge are shown to be described by a conformal sigma model, which is a marginal integrable deformation of six-dimensional SL(2,R) x SU(2) WZW model. The two WZW levels are equal to the five-brane charge, while the parameters of the two marginal deformations

O. M. Del Cima, K. Landsteiner, M. Schweda

We reinvestigate the twisted N=4 supersymmetry present in Schwarz type topological field models. We show that Chern-Simons theory in three dimensions can be untwisted to a kind of sigma-model with reversed statistics only in the free case. By dimensional reduction we define then the two-dimensional BF-model. We establish an analog result concerning the untwi

Manfred Requardt

Starting from the working hypothesis that both physics and the corresponding mathematics have to be described by means of discrete concepts on the Planck scale, one of the many problems one has to face in this enterprise is to find the discrete protoforms of the building blocks of our ordinary continuum physics and mathematics. We base our own approach on wh

Z. Chacko, Markus A. Luty, Eduardo Ponton

We propose a mechanism for generating the GUT scale dynamically from the Planck scale. The idea is that the GUT scale is fixed by the vacuum expectation value of a "GUT modulus" field whose potential is exactly flat in the supersymmetric limit. If supersymmetry is broken by gauge mediation, a potential for the GUT modulus is generated at 2 loops, and

Fayyazuddin

It is shown that interference of the amplitudes for the decays $Λ_b \to ΛD$ and $Λ_b \to Λ\bar{D}^0$ gives rise to CP-violation.

Kari Enqvist, Petteri Keränen, Jukka Maalampi

We propose to test the magnetic transition moments of Majorana neutrinos by comparing the fluxes of different flavours of neutrinos coming from active galactic nuclei (AGN). We show that, with reasonable assumptions about the magnetic field of the AGN, it is possible to obtain limits on $ν_τν_{e}$ and $ν_τν_μ$ transition moments which are three to five order

C. -H. Lee, H. Yamagishi, I. Zahed

We extend our early analyses of the dilepton and photon emission rates from a hadronic gas to account for strange mesons using a density expansion. The emission rates are reduced to vacuum correlation functions using three-flavor chiral reduction formulas, and the latters are assessed in terms of empirical data. Using a fire-ball, we compare our results to t

E. Chopin

In this paper, we present an improvement of a method for computing scattering amplitudes that include external (polarized) fermions with the following features: the formulas are quite general and work for different kinematic configurations and different external masses, they are explicitly covariant, they do not depend on a specific representation of the Dir

R. Fiore, F. Gliozzi, P. Provero

We show that universality arguments, namely the Svetitsky-Yaffe conjecture, allow one to obtain exact results on the critical behavior of 3D SU(2) gauge theory at the finite temperature deconfinement transition,through a mapping into the 2D Ising model. In particular, we consider the finite-size scaling behavior of the plaquette operator, which can be mapped

OBELIX Collaboration, V. Alberico, A. Bertin

The proton-antiproton annihilation at rest into the $ϕη$ final state was measured for three different target densities: liquid hydrogen, gaseous hydrogen at NTP and at a low pressure of 5 mbar. The yield of this reaction in the liquid hydrogen target is smaller than in the low-pressure gas target. The branching ratios of the $ϕη$ channel were calculated on t

C. J. Fama, C. J. S. Clarke

Following a survey of the abstract boundary definition of Scott and Szekeres, a rigidity result is proved for the smooth case, showing that the topological structure of the regular part of this boundary in invariantly defined.

N. Markovic, A. M. Mack, G. Martinez-Arizala, C. Christiansen

The magnetoresistance of ultrathin insulating films of Bi has been studied with magnetic fields applied parallel and perpendicular to the plane of the sample. Deep in the strongly localized regime, the magnetoresistance is negative and independent of field orientation. As film thicknesses increase, the magnetoresistance becomes positive, and a difference bet

Shi-Jie Xiong, S. N. Evangelou, E. N. Economou

We obtain analytically a continuum of one-dimensional ballistic extended states in a two-dimensional disordered system, which consists of compactly coupled random and pure square lattices. The extended states give a marginal metallic phase with finite conductivity $σ_{0}=2e^2/h$ in a wide energy range, whose boundaries define the mobility edges of a first-or

Richard P. Sear

Hard spheres with a polydispersity above approximately 8% are shown to crystallise into two phase-separated solid phases. A polydispersity above 8% is too large to be tolerated by a single solid phase but phase separation produces two fractions with polydispersities sufficiently narrow to allow them to crystallise. It may not be possible to observe this in e

Alok Shukla, Michael Dolg, Hermann Stoll

A recently proposed ab initio Hartree-Fock approach aimed at directly obtaining the Wannier functions of a crystalline insulator is applied to polymers. The systems considered are the LiH chain and trans-polyacetylene. In addition to being the first application of our approach to one-dimensional systems, this work also demonstrates its applicability to coval

V. T. Dolgopolov, A. A. Shashkin, E. V. Deviatov, F. Hastreiter

We employ magnetocapacitance and far-infrared spectroscopy techniques to study the spectrum of the double-layer electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. For gate-bias-controlled asymmetric electron density distributions in this soft two-subband system we observe both individual subband gaps and double layer gaps

Yusuke Kato

We obtain an exact result on single hole dynamics in one-dimensional Mott-insulators through the study on the supersymmetric t-J model with long range interaction at half-filling. We calculate the expression G_{1s1h}(x,t) for one spinon one holon contribution to the hole propagator. We find that G_{1s1h}(x=0,t=0)=3/8, which amounts to 75% of the spin-fixed m

Markus Holzmann, Werner Krauth, Martin Naraschewski

We compare the semiclassical Hartree-Fock approximation for a trapped Bose gas to a direct Path Integral Quantum Monte Carlo simulation. The chosen parameters correspond to current Rb experiments. We observe corrections to the mean-field density profile. The Path Integral calculation reveals an increase of the number of condensed particles, which is of the s

D. Braak, N. Andrei

The Bethe Ansatz equations for the one-dimensional Hubbard model are reexamined. A new procedure is introduced to properly include bound states. The corrected equations lead to new elementary excitations away from half-filling.

Vyacheslav V. Stepanov, Gerhard Muller

We consider a two-spin model, represented classically by a nonlinear autonomous Hamiltonian system with two degrees of freedom and a nontrivial integrability condition, and quantum mechanically by a real symmetric Hamiltonian matrix with blocks of dimensionalities K=l(l+1)/2, l=1,2,... In the six-dimensional (6D) parameter space of this model, classical inte

Gregor Hackenbroich, Jens U. Noeckel

The lifetime of whispering gallery modes in a dielectric cavity with a metallic inclusion is shown to fluctuate by orders of magnitude when size and location of the inclusion are varied. We ascribe these fluctuations to tunneling transitions between resonances quantized in different regions of phase space. This interpretation is confirmed by a comparison of

Hanadi M. AbdelSalam, Prasenjit Saha, Liliya L. R. Williams

We apply a new non-parametric technique to reconstruct, with uncertainties, the projected mass distribution of the inner region of Abell 2218, using combined strong and weak lensing constraints from multiple-image systems and arclets with known redshifts. The reconstructed mass map broadly resembles previous, less detailed, parametric models, but when examin

L. Armus, K. Matthews, G. Neugebauer, B. T. Soifer

Imaging at 1.25 and 2.20 microns has been obtained of the field containing the galaxy (RD1) found at redshift 5.34 by Dey et al.(1998). This galaxy has been detected at 1.25 microns, while the lower redshift (z=4.02) galaxy also found in the same field by Dey et al. was detected at both 1.25 and 2.20 microns. Comparison to stellar population synthesis models

Glennys R. Farrar, Peter L. Biermann

Some proposals to account for the highest energy cosmic rays predict that they should point to their sources. We study the five highest energy events (E>10^20 eV) and find they are all aligned with compact, radio-loud quasars. The probability that these alignments are coincidental is 0.005, given the accuracy of the position measurements and the rarity of su

Barron Koralesky, L. Rudnick, E. V. Gotthelf, J. W. Keohane

We present the first X-ray expansion measurement of the SNR Cas A. We compared new ROSAT to archived Einstein HRI images with a separation of 17 years. The remnant is seen to be expanding, on average, at a rate of 0.20 %/yr, which is twice as fast as the expansion of the bright radio ring and two-thirds as fast as the ensemble of optical Fast Moving Knots. T

Caryl Gronwall

The KPNO International Spectroscopic Survey (KISS) is a wide-field survey for extragalactic emission-line objects being carried out with the Burrell Schmidt at Kitt Peak. The critical difference between this survey and classical objective-prism surveys for active galaxies is the use of a CCD detector which allows us to probe to much fainter magnitudes than p

John J. Salzer

Searches for low-metallicity galaxies are reviewed, focusing mainly on efforts to discover systems that are relevant for use in measuring the primordial helium abundance. Wide-field objective-prism surveys for blue or emission-line galaxies have played a major role in this field. Previous surveys and search techniques are highlighted. Preliminary results fro

Vijay K. Narayanan, David H. Weinberg

In reconstruction analysis of galaxy redshift surveys, one works backwards from the observed galaxy distribution to the primordial density field in the same region, then evolves the primordial fluctuations forward in time with an N-body code. This incorporates assumptions about the cosmological parameters, the properties of primordial fluctuations, and the b

A. Kashlinsky

It is shown how data on the cluster correlation function can be used in order to reconstruct the density of the pregalactic density field on the cluster mass scale. The method is applied to the data on the cluster correlation amplitude -- richness dependence. The spectrum of the recovered density field has the same shape as the density field derived from dat

G. Israelian, R. Garcia Lopez, R. Rebolo

We have performed a detailed oxygen abundance analysis of 23 metal-poor (-3.0<[Fe/H]<-0.3) unevolved halo stars and one giant through the OH bands in the near UV, using high-resolution echelle spectra. Oxygen is found to be overabundant with respect to iron in these stars, with the [O/Fe] ratio increasing from 0.6 to 1 between [Fe/H]=-1.5 and -3.0. The behav

C. Soubiran, D. Katz, R. Cayrel

A library of 211 echelle spectra taken with ELODIE at the Observatoire de Haute-Provence is presented. It provides a set of spectroscopic standards covering the full range of gravities and metallicities in the effective temperature interval [4000 K, 6300 K]. The spectra are straightened, wavelength calibrated, cleaned of cosmic ray hits, bad pixels and tellu

D. Katz, C. Soubiran, R. Cayrel, M. Adda

We present a method estimating the atmospheric parameters Teff, log g, [Fe/H] for stars observed, even at low signal to noise ratio, with the echelle spectrograph ELODIE on the 193cm telescope at Observatoire de Haute-Provence. The method relies on the least-square comparison of the spectrum of a target star to a library of 211 spectra of reference stars for

S. Mao, J. Reetz, D. L. Lennon

We propose a new method to detect the gravitational lenses in the ongoing microlensing experiments using medium and high resolution spectroscopy (resolution > 6000). Since the radial velocity of the lens and lensed source typically differs by ~100km/s, the spectral lines from the lens and source will be shifted relative to each other by (1-2)A in the optical

V. Barger, S. Pakvasa, T. J. Weiler, K. Whisnant

We show that if the solar and atmospheric data are both described by maximal vacuum oscillations at the relevant mass scales then there exists a unique mixing matrix for three neutrino flavors. The solution necessarily conserves CP and automatically implies that there is no disappearance of atmospheric $ν_e$, consistent with indications from the Super-Kamiok

Jean Letessier, Johann Rafelski

We interpret hadronic particle abundances produced in S--Au/W/Pb 200 A GeV reactions in terms of the final state hadronic phase space model and determine by a data fit of the chemical hadron freeze-out parameters. Allowing for the flavor abundance non-equilibrium a highly significant fit to experimental particle abundance data emerges, which supports possibi

Gerhard Hummer, Lawrence R. Pratt, Angel E. Garcia

Recent developments in molecular theories and simulation of ions and polar molecules in water are reviewed. The hydration of imidazole and imidazolium solutes is used to exemplify the theoretical issues. The treatment of long-ranged electrostatic interactions in simulations is discussed extensively. It is argued that the Ewald approach is an easy way to get

C. R. Allton, L. Conti, A. Donini, V. Gimenez

We present a calculation of the matrix elements of the most general set of DeltaS=2 dimension-six four-fermion operators. The values of the matrix elements are given in terms of the corresponding B-parameters. Our results can be used in many phenomenological applications, since the operators considered here give important contributions to K^0--K^0bar mixing

Thomas Vojta, Frank Epperlein, Michael Schreiber

We investigate the influence of electron-electron interactions on the conductance of two-dimensional disordered spinless electrons. By using an efficient numerical method which is based on exact diagonalization in a truncated basis of Hartree-Fock states we are able to determine the exact low-energy properties of comparatively large systems in the diffusive

C. Manuel, N. Rius

We compute low temperature corrections to the electromagnetic mass difference of pions in the chiral limit. The computation is done in a model independent way in the framework of chiral perturbation theory, using the background field method and the hard thermal loop approximation. We also generalize at low temperature the sum rule of Das et al. We find that

S. Kuemmel, M. Brack, P. -G. Reinhard

We present ground-state configurations and photoabsorption spectra of Na-7+, Na-27+ and Na-41+. Both the ionic structure and the photoabsorption spectra of medium-size sodium clusters beyond Na-20 have been calculated self-consistently with a nonspherical treatment of the valence electrons in density functional theory. We use a local pseudopotential that has

A. I. Posazhennikova, M. V. Sadovskii

We propose a toy model of electronic spectrum of two-dimensional system with ``hot-patches&#39;&#39; on the Fermi surface, which leads to essential renormalization of spectral density (pseudogap). Within this model we derive Ginzburg-Landau expansion for both s-wave and d-wave Cooper pairing and analyze the influence of pseudogap formation on the basic prope

A. Abada, J. Matias, R. Pittau

We justify the feasibility of substituting a photon leg by a neutrino current in the Euler-Heisenberg Lagrangian to obtain an effective Lagrangian for the process $γν\toγγν$ and its crossed reactions. We establish the link between these processes and the four-photon scattering in both the Standard Model and the effective theory. As an application, we compute

Ralph Blumenhagen, Andreas Wisskirchen

We compute the massless spectra of some four dimensional, N=1 supersymmetric compactifications of the type I string. The backgrounds are non-toroidal Calabi-Yau manifolds described at special points in moduli space by Gepner models. Surprisingly, the abstract conformal field theory computation reveals Chan-Paton gauge groups as big as SO(12) x SO(20) or SO(8

Philip G. Ratcliffe

On the basis of a previous analysis of hyperon semi-leptonic decay data, a prediction is presented for g_1/f_1 in the Xi^0 -> Sigma^+ e nu-bar beta-decay. The analysis takes into account SU(3) breaking in this sector via the inclusion of mass-driven corrections. A rather precise measurement of the above channel by the KTeV experiment at Fermilab will shortly

M. Zyskin

A conjectured duality between supergravity and $N=\infty$ gauge theories gives predictions for the glueball masses as eigenvalues for a supergravity wave equations in a black hole geometry, and describes a physics, most relevant to a high-temeperature expansion of a lattice QCD. We present an analytical solution for eigenvalues and eigenfunctions, with eigen

R. Horvat

We consider the pulsar velocity problem and relate it to some unconventional neutrino oscillation mechanisms based on a violation of the equivalence principle by neutrinos. We show that the observed pulsar velocities may be explained by violations at the level from 10^{-9} to 10^{-10} in the case of a non-universal tensor neutrino-gravity coupling, whereas t

Mark Nelkin

Writing the Poisson equation for the pressure in the vorticity-strain form, we show that the pressure has a finite inertial range spectrum for high Reynolds number isotropic turbulence only if the anomalous scaling exponents $μ$ and $μ_ω$ for the dissipation and enstrophy (squared vorticity) are equal. Since a finite inertial range pressure spectrum requires

M. R. Wegewijs, Yu. V. Nazarov

We theoretically investigate resonant tunneling through a linear array of quantum dots with subsequent tunnel coupling. We consider two limiting cases: (i) strong Coulomb blockade, where only one extra electron can be present in the array (ii) limit of almost non-interacting electrons. We develop a density matrix description that incorporates the coupling of

Fabio Riccioni, Augusto Sagnotti

In this note we clarify some issues in six-dimensional (1,0) supergravity coupled to vector and tensor multiplets. In particular, we show that, while the low-energy equations embody tensor-vector couplings that contribute only to gauge anomalies, the divergence of the energy-momentum tensor is properly non-vanishing. In addition, we show how to revert to a s

Daniel M. Danchev, Nicholay S. Tonchev

The behavior of the finite-temperature C-function, defined by Neto and Fradkin [Nucl. Phys. B {\bf 400}, 525 (1993)], is analyzed within a d -dimensional exactly solvable lattice model, recently proposed by Vojta [Phys. Rev. B {\bf 53}, 710 (1996)], which is of the same universality class as the quantum nonlinear O(n) sigma model in the limit $n\to \infty$.

P. Salucci, M. Persic

We compute the baryonic mass function (BMF) of disc galaxies using the best LFs and baryonic M/L ratios reliable for this goal. For baryonic masses (M_b) ranging between 10^8 and 10^{11} solar masses, the BMF is featureless, i.e. it scales as M_b^{-1/2}. Outside this mass range, the BMF is a strong inverse function of M_b. The contributions to the baryon den

Alok Kumar, Subir Mukhopadhyay

We explicitly write down the invariant supersymmetry conditions for branes with generic values of moduli and U-duality charges in various space-time dimensions $D \leq 10$. We then use these results to obtain new BPS states, corresponding to network type structure of such branes.

K. Ishikawa, N. Maeda, T. Ochiai, H. Suzuki

We construct useful sets of one-particle states in the quantum Hall system based on the von Neumann lattice. Using the set of momentum states, we develop a field-theoretical formalism and apply the formalism to the system subjected to a periodic potential. The topological formula of the Hall conductance written by the winding number of propagator is generali

Alex J. Dragt, Salman Habib

It is shown that, while Wigner and Liouville functions transform in an identical way under linear symplectic maps, in general they do not transform identically for nonlinear symplectic maps. Instead there are ``quantum corrections&#39;&#39; whose hbar tending to zero limit may be very complicated. Examples of the behavior of Wigner functions in this limit ar

Murray Peshkin

Zeilinger&#39;s observation that phenomena of the Aharonov-Bohm type lead to nondispersive, i.e. energy-independent, phase shifts in interferometers is generalized in a new proof which shows that the precise condition for nondispersivity is a force-free interaction. The converse theorem is disproved by a conceptual counter example. Applications to several no

Christian Wiele, Fritz Haake, Kazimierz Rzazewski

We solve the superradiant laser model in two limiting cases. First the stationary low-pumping regime is considered where a first-order phase transition in the semiclassical solution occurs. This discontinuity is smeared out in the quantum regime. Second, we solve the model in the non-stationary regime where we find a temporally periodic solution. For a certa

David M. Schmidt, John S. George, C. C. Wood

We present a new approach to the electromagnetic inverse problem that explicitly addresses the ambiguity associated with its ill-posed character. Rather than calculating a single ``best&#39;&#39; solution according to some criterion, our approach produces a large number of likely solutions that both fit the data and any prior information that is used. While

Jens U. Noeckel, A. Douglas Stone, Gang Chen, Helene L. Grossman

Asymmetric resonant cavities (ARCs) with highly non-circular but convex cross-sections are predicted theoretically to have high-Q whispering gallery modes with very anisotropic emission. We develop a ray dynamics model for the emission pattern and present numerical and experimental confirmation of the theory.

Sangyong Jeon, Joseph Kapusta, Alexei Chikanian, Jack Sandweiss

The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Soft photons can be used to infer the rapidity distribution of the outgoing charge. An experimental design is outlined.

A. N. Kvinikhidze, B. Blankleider

We show how to obtain a complete set of electromagnetic corrections to a given nonperturbative model of strong interactions based on integral equations. The gauge invariance of these corrections is a consequence of their completeness.

P. F. Bedaque

We discuss the effective field theory approach to nuclear phenomena with typical momentum below the pion mass. We particularly focus on the three body problem. In the $J=3/2$ channel,effective field theory is extremelly predictive and we are able to describe the nucleon-deuteron scattering amplitude at the percent level using only two parameters obtained fro

Christof Kuelske

We investigate the Gibbs-measures of ferromagnetically coupled continuous spins in double-well potentials subjected to a random field (our specific example being the $ϕ^4$ theory), showing ferromagnetic ordering in $d\geq 3$ dimensions for weak disorder and large energy barriers. We map the random continuous spin distributions to distributions for an Ising-s

Maks A. Akivis, Vladislav V. Goldberg

On the Grassmann manifold G (m, n) of m-dimensional subspaces of an n-dimensional projective space P^n, a certain supplementary construction called the normalization is considered. By means of this normalization, one can construct the structure of a Riemannian or semi-Riemannian manifold or an affine connection on G(m, n).

Maks A. Akivis, Vladislav V. Goldberg

There are three types of hypersurfaces in a pseudoconformal space C^n_1 of Lorentzian signature: spacelike, timelike, and lightlike. These three types of hypersurfaces are considered in parallel. Spacelike hypersurfaces are endowed with a proper conformal structure, and timelike hypersurfaces are endowed with a conformal structure of Lorentzian type. Geometr

Oliver T. Dasbach

We prove that the dimension of the space of primitive Vassiliev invariants of degree n grows - as n tends to infinity - faster than Exp(c Sqrt(n)) for any c < Pi Sqrt (2/3). The proof relies on the use of the weight systems coming from the Lie algebra gl(N). In fact, we show that our bound is - up to multiplication with a rational function in n - the best po

P. Bozhilov

We consider a model for tensionless (null) super p-branes in the Hamiltonian approach and in the framework of a harmonic superspace. The obtained algebra of Lorentz-covariant, irreducible, first class constraints is such that the BRST charge corresponds to a first rank system.

F. Antonuccio, O. Lunin, S. Pinsky, H. -C. Pauli

We consider the 1+1 dimensional N = (8,8) supersymmetric matrix field theory obtained from a dimensional reduction of ten dimensional N = 1 super Yang-Mills. The gauge groups we consider are U(N) and SU(N), where N is finite but arbitrary. We adopt light-cone coordinates, and choose to work in the light-cone gauge. Quantizing this theory via Discretized Ligh

Marika Taylor-Robinson

We consider scattering of minimally coupled scalars from a six-dimensional black string carrying one and five brane charges but no Kaluza-Klein momentum. The leading correction to the absorption cross section is found by improved matching of inner and outer solutions to the wave equation. The world sheet interpretation of this correction follows from the bre

M. Chaichian, W. F. Chen

We find the inconsistency of dimensional reduction and naive dimensional regularization in their applications to Chern-Simons type gauge theories. Further we adopt a consistent dimensional regularization to investigate the quantum correction to non-Abelian Chern-Simons term coupled with fermionic matter. Contrary to previous results, we find that not only th

M. V. Polyakov, C. Weiss

We calculate the two-pion light-cone distribution amplitudes in the effective low-energy theory based on the instanton vacuum. These generalized distribution amplitudes describe the soft (non-perturbative) part of the process $\gamma^*\gamma \to \pi\pi$ in the region where the c.m. energy is much smaller than the photon virtuality. They can also be used in t

R. Akhoury, M. G. Sotiropoulos, G. Sterman

A novel factorization formula is presented for the longitudinal structure function $F_L$ near the elastic region $x \to 1$ of deeply inelastic scattering. In moment space this formula can resum all contributions to $F_L$ that are of order $\ln^k N/N$. This is achieved by defining a new jet function which probes the transverse momentum of the struck parton in

Konstantin Goulianos

We summarize the main features of available experimental results on soft and hard diffraction and draw conclusions about the nature of the pomeron.

A. G. Akeroyd, Marco A. Diaz, Jose W. F. Valle

In bilinear R-Parity violating models where a term ε_3L_3H_2 is introduced in the superpotential, the tau lepton can mix with charginos. We show that this mixing is fully compatible with LEP1 precision measurements of the Zττand Wτν_τcouplings even for large values of ε_3 and of the induced vacuum expectation value v_3 of the tau-sneutrino. The single produc

B. Povh

A geometrical model of hadron-proton interactions has been extended to describe gamma-proton total cross section measured in deep-inelastic scattering at small x (x<0.04). Experimental data are consistent with this model assuming that the hadronic fluctuation of the virtual photon has a size of <r^2> ~ 1/(4m_q^2 + Q^2), where m_q is the mass of the light con

Harald Fritzsch

Flavor mixing and the quark mass spectrum are intimately related. In view of the observed strong hierarchy of the quark and lepton masses and of the flavor mixing angles it is argued that the description of flavor mixing must take this into account. One particular interesting way to describe the flavor mixing emerges, which is particularly suited for models

W. Melnitchouk

We review recent experimental and theoretical developments in the study of the sea quark structure of the proton. In the light quark sector, we analyse the recent pp and pD Drell-Yan data from the E866/NuSea experiment at Fermilab, and their implication for the d-bar/u-bar asymmetry in the proton. The current status of the strange content of the proton, incl

Anjan S. Joshipura, A. Yu. Smirnov

The see-saw mechanism for neutrino masses based on the Grand Unification leads to the mass of the heaviest neutrino ($\approx ν_τ$) in the range $(2 - 3)\cdot 10^{-3}$ eV and hence to a solution of the solar neutrino problem through the $ν_e-ν_\t$ conversion. We suggest the existence of a light singlet fermion $S$ which mixes predominantly with muon neutrino

Morimitsu Tanimoto

We propose the indirect search for the CP violating phase in the long baseline $\n_\m \Ar\n_e$ oscillation experiment, in which two scenarios of the neutrino mass hierarchy are discussed in the three family model. The CP violatig phase effect is clearly found in the scenario: the LSND data plus the atmospheric neutrino deficit. The phase dependence of the os

TARO Collaboration, Ph. de Forcrand et al

We calculate numerically the renormalization group (RG) flow of lattice QCD in two-coupling space, $(β_{1\times 1},β_{1\times 2})$. This is the first explicit calculation of the RG flow of SU(3) gauge theory. From the RG flow,a renormalized trajectory (RT) is revealed. Its behavior is consistent with the strong coupling expansion near the high-temperature fi

T. Wengler

High transverse momentum pi^0 -mesons and charged particles are measured in deep inelastic e-p scattering events at low Bjorken-x taken with the H1 detector at HERA. The production of high-pt particles is strongly correlated to the emission of hard partons in QCD and is therefore sensitive to the dynamics of the strong interaction. For the first time the mea

Makoto Minowa, Shigetaka Moriyama, Yoshizumi Inoue, Toshio Namba

A preliminary result of the solar axion search experiment at the University of Tokyo is presented. We searched for axions which could be produced in the solar core by exploiting the axion helioscope. The helioscope consists of a superconducting magnet with field strength of 4 Tesla over 2.3 meters. From the absence of the axion signal we set a 95 % confidenc

Kamiokande Collaboration, M. Shiozawa

We have searched for proton decay via p -> e+ pi0 using data from a 25.5 kton-year exposure of the Super-Kamiokande detector. We find no candidate events with an expected background induced by atmospheric neutrinos of 0.1 events. From these data, we set a lower limit on the partial lifetime of the proton to be 1.6E33 years at a 90% confidence level.

Dan N. Vollick

It is well known that it takes matter that violates the averaged weak energy condition to hold the throat of a wormhole open. The production of such ``exotic&#39;&#39; matter is usually discussed within the context of quantum field theory. In this paper I show that it is possible to produce the exotic matter required to hold a wormhole open classically. This

Marcelo Salgado, Daniel Sudarsky, Ulises Nucamendi

We study in the physical frame the phenomenon of spontaneous scalarization that occurs in scalar-tensor theories of gravity for compact objects. We discuss the fact that the phenomenon occurs exactly in the regime where the Newtonian analysis indicates it should not. Finally we discuss the way the phenomenon depends on the equation of state used to describe

Paul R. Anderson, Courtney D. Mull

We show that a gap exists in the allowed sizes of all zero temperature static spherically symmetric black holes in semiclassical gravity when only conformally invariant fields are present. The result holds for both charged and uncharged black holes. By size we mean the proper area of the event horizon. The range of sizes that do not occur depends on the numb

J. A. Vickers, J. P. Wilson

An explicit calculation is carried out to show that the distributional curvature of a 2-cone, calculated by Clarke et al. (1996), using Colombeau&#39;s new generalised functions is invariant under non-linear $C^\infty$ coordinate transformations.

Andrey V. Chubukov, Dirk K. Morr

We present an explanation of the unusual peak/dip/hump features observed in photoemission experiments on Bi2212 at $T \ll T_c$. We argue that these features arise from the interaction of the fermionic quasi-particles with overdamped spin fluctuations. We show that the strong spin-fermion interaction combined with the feedback effect on the spin damping due t

D. A. Garanin

Dimensional crossover of ordering in ferromagnetic films with both periodic and free boundary conditions is studied for the exactly solvable uniaxial model of classical D-component spin vectors in the limit D \to \infty. Analytical and numerical solution of the exact equations describing this model shows that for lattice dimensionalities d>4, finite-size cor

Régis Mélin, Hao Li, Ned S. Wingreen, Chao Tang

In the framework of a lattice-model study of protein folding, we investigate the interplay between designability, thermodynamic stability, and kinetics. To be ``protein-like&#39;&#39;, heteropolymers must be thermodynamically stable, stable against mutating the amino-acid sequence, and must be fast folders. We find two criteria which, together, guarantee tha

Nicola Manini, Paolo De Los Rios

The presence/absence of a Berry phase depends on the topology of the manifold of dynamical Jahn-Teller potential minima. We describe in detail the relation between these topological properties and the way the lowest two adiabatic potential surfaces get locally degenerate. We illustrate our arguments through spherical generalizations of the linear T x h and H

Michael W. Deem, Jeong-Man Park

We analyze the reactions $A+A \to \emptyset$ and $A + B \to \emptyset$ occurring in a model of turbulent flow in two dimensions. We find the reactant concentrations at long times, using a field-theoretic renormalization group analysis. We find a variety of interesting behavior, including, in the presence of potential disorder, decay rates faster than that fo

T. Ruth Goldin, Baruch Horovitz

We study elasticity of a perpendicular flux lattice in a layered superconductor with Josephson coupling between layers. We find that the energy contains ln(flux displacement) terms, so that elastic constants cannot be strictly defined. Instead we define effective elastic constants by a thermal average. The tilt modulus has terms with ln(T) which for weak fie

P. Prelovsek, J. Jaklic, K. Bedell

The variation of single-particle spectral functions with doping is studied numerically within the t-J model. It is shown that corresponding self energies change from local ones at the intermediate doping to strongly nonlocal ones for a weakly doped antiferromagnet. The nonlocality shows up most clearly in the pseudogap emerging in the density of states, due