August 1999 arXiv papers — page 16

Vladimir Tchernov

We show that for a big class of contact manifolds the groups of order $\leq n$ invariants (with values in an arbitrary Abelian group) of Legendrian, of transverse and of framed knots are canonically isomorphic. On the other hand for an arbitrary cooriented contact structure on $S^1\times S^2$ with the nonzero Euler class of the contact bundle we construct ex

D. Shklyarov, S. Sinel'shchikov, L. Vaksman

We have introduced q-analogues of bounded symmetric domains in our work q-alg/9703005. Given the simplest ones among those, the works q-alg/9603012 and math.QA/9803110 announce the relations describing the algebras of functions, differential and integral calculi. This paper presents the proofs of these results.

Oren Bergman, Amihay Hanany, Andreas Karch, Barak Kol

It is shown that supersymmetry is spontaneously broken in certain three-dimensional supersymmetric gauge theories, by using the s-rule in their string theory realization as brane configurations. In particular, supersymmetry is broken in N=3 supersymmetric Yang-Mills-Chern-Simons theory with gauge group SU(n) and CS coefficient k, as well as in its N=2 and N=

A. Casher, Y. Shamir

We show that supersymmetry Ward identities contain an anomalous term which takes the form of a surface term in Hilbert space. In the one-instanton sector the anomalous term is the integral of a total rho-derivative where rho is the instanton's size. There are cases where the anomalous term is non-zero, and cannot be modified by subtractions. This constit

Ronald J. Adler, David I. Santiago

We here consider a generalization of the Klein-Gordon scalar wave equation which involves a single arbitrary function. The quantization may be viewed as allowing $\hbar$ to be a function of the momentum or wave vector rather than a constant. The generalized theory is most easily viewed in the wave vector space analog of the Lagrangian. We need no reference t

Dmitri Diakonov

At high temperatures the A_0 component of the Yang--Mills field plays the role of the Higgs field, and the 1-loop potential V(A_0) plays the role of the Higgs potential. We find a new stable vortex solution of the Abrikosov-Nielsen-Olesen type, and discuss its properties and possible implications.

A. T. Filippov, V. G. Ivanov

Global canonical transformations to free chiral fields are constructed for DG models minimally coupled to scalar fields. The boundary terms for such canonical transformations are shown to vanish in asymptotically static coordinates if there is no scalar field.

S. Nojiri, S. D. Odintsov, S. Ogushi, A. Sugamoto

We discuss general multidimensional axion-dilatonic AdS gravity which may correspond to bosonic sector of Gibbons-Green-Perry (compactified) IIB supergravity with RR-scalar (axion). Using AdS/CFT correspondence the 4d conformal anomaly on axion-dilaton-gravitational background is found from SG side. It is shown that for IIB SG with axion such conformal anoma

Chang-Ho Kim, Young-Jai Park

We study a novel five-dimensional, {\it N}=5 supergravity in the context of Lie superalgebra SU(5/2). The possible successive superalgebraic truncations from {\it N}=5 theory to the lower supersymmetric {\it N}=4,3,2, and 1 supergravity theories are systematically analyzed as a sub-superalgebraic chain of SU(5/2)$\supset$ SU(4/2) $\supset$ SU(3/2) $\supset$

Ken-Ichi Kubota, Haruhiko Terao

Non-perturbative renormalizability, or non-triviality, of the gauged Nambu-Jona-Lasinio (NJL) model in four dimensions is examined by using non-perturbative (exact) renormalization group in large $N_c$ limit. When running of the gauge coupling is asymptotically free and slow enough, the two dimensional renormalized trajectory (subspace) spanned by the four f

Toby Falk, Andrew Ferstl, Keith A. Olive

We analyze the neutralino-nucleus elastic cross-section in the MSSM, including contributions from CP-violating phases, using the four-fermi neutralino-quark interaction. Over a wide range of the MSSM parameter space we show the variations in the cross-sections due to these phases. We further concentrate on the regions which are consistent with constraints fr

Jonathan L. Feng, Konstantin T. Matchev, Takeo Moroi

For a top quark mass fixed to its measured value, we find natural regions of minimal supergravity parameter space where all squarks, sleptons, and heavy Higgs scalars have masses far above 1 TeV and are possibly beyond the reach of the Large Hadron Collider at CERN. This result is simply understood in terms of ``focus point'' renormalization group be

M. M. Guzzo, H. Nunokawa, O. L. G. Peres, V. Pleitez

Theoretical models which present flavor changing neutrino interactions and simultaneously prevent this particle from acquiring any mass exist. We discuss some of them and their predictions for neutrino oscillations in matter which can account for the solar neutrino anomaly as well as the zenith-angle dependence of the deficit of atmospheric neutrinos observe

J. R. Forshaw, M. H. Seymour

We calculate the subjet rates for jets produced in hadron collisions. The kt algorithm is used to define the jets and allows the theoretical calculation to sum both the leading and next-to-leading logarithms in the resolution variable, ycut. We also ensure that our calculation matches exactly the leading order in alpha_s result and has sensible behaviour nea

Dan Pirjol

Determinations of the CKM phase $γ$ from weak nonleptonic $B$ decays are affected by electroweak (EW) penguins and rescattering effects. In this talk it is explained how the EW penguin effects can be controlled with the help of SU(3) symmetry, by relating them to tree-level amplitudes. The impact of the final-state interactions on the determination of $γ$ fr

G. P. Korchemsky, J. Wosiek

New representation of the odderon wave function is derived, which is convergent in the whole impact parameter plane and provides the analytic form of the quantization condition for the integral of motion q_3. A new quantum number, triality, is identified. This, together with the choice of the conformal basis, allows for simple calculation of eigenvalues of a

R. J. M. Covolan, A. V. Kisselev, M. S. Soares

The charm contribution to the structure functions of diffractive deep inelastic scattering is considered here within the context of the Ingelman-Schlein model. Numerical estimations of this contribution are made from parametrizations of the HERA data. Influence of the Pomeron flux factor is analized as well as the effect of the shape of the initial parton di

Jihn E. Kim, Jae Sik Lee

If there exist only three light neutrinos below the weak scale, the neutrino masses can arise by breaking the lepton number L. One example is the Zee mechanism for the neutrino masses. We study phenomenological implications of neutrino masses arising from the L violation through introduction of SU(2) X U(1) singlet scalars with Q_{em}=1 and 2.

Thomas E. Jannakos

Results from the search for muon anti neutrino to electron anti neutrino oscillations with the karmen experiment. Results are based on the data taken from Feb.97 to Feb.99.

Carlos Barcelo, Matt Visser

The massless conformally coupled scalar field is characterized by the so-called "new improved stress-energy tensor", which is capable of classically violating the null energy condition. When coupled to Einstein gravity we find a three-parameter class of exact solutions. These exact solutions include the Schwarzschild geometry, assorted naked singular

Sabrina Bedard, Laurent J. Lewis

The coefficient of diffusion of hydrogen in crystalline silicon is calculated using tight-binding molecular dynamics. Our results are in good quantitative agreement with an earlier study by Panzarini and Colombo [Phys. Rev. Lett. 73, 1636 (1994)]. However, while our calculations indicate that long jumps dominate over single hops at high temperatures, no abru

L. P. Rokhinson, L. J. Guo, S. Y. Chou, D. C. Tsui

We have studied low-temperature single electron transport through ultra-small Si quantum dots. We find that at low temperatures Coulomb blockade is partially lifted at certain gate voltages. Furthermore, we observed an enhancement of differential conductance at zero bias. The magnetic field dependence of this zero bias anomaly is very different from the one

Andre G. Moreira, Roland R. Netz

Using field-theoretic methods, we calculate the internal energy for the One-Component Plasma (OCP). We go beyond the recent calculation by Brilliantov [N. Brilliantov, Contrib. Plasma Phys. 38, pg. 489 (1998) / cond-mat/9805358] by including non-Gaussian terms. We show that, for the whole range of the plasma parameter Gamma, the effect of the higher-order te

S. R. Saha, H. Sugawara, T. D. Matsuda, H. Sato

Electrical resistivity ($ρ$), magnetoresistance (MR), magnetization, thermopower and Hall effect measurements on the single crystal Gd$_{2}$PdSi$_3$, crystallizing in an AlB$_2$-derived hexagonal structure are reported. The well-defined minimum in $ρ$ at a temperature above Néel temperature (T$_N$= 21 K) and large negative MR below $\sim$ 3T$_N$, reported ea

P. M. Echenique, J. M. Pitarke, E. V. Chulkov, A. Rubio

Electron dynamics in the bulk and at the surface of solid materials are well known to play a key role in a variety of physical and chemical phenomena. In this article we describe the main aspects of the interaction of low-energy electrons with solids, and report extensive calculations of inelastic lifetimes of both low-energy electrons in bulk materials and

Kouji Segawa, Yoichi Ando

The in-plane normal-state resistivity of Zn-doped YBa2Cu3O7-d and heavily underdoped pure YBCO single crystals is measured down to low temperatures under magnetic fields up to 18 T. We found that the temperature dependence of the normal-state rho_ab does not obey log(1/T) and tends not to diverge in the low temperature limit. The result suggests that the ``g

A. Bäker, L. Schweitzer

Frequency dependent electronic transport is investigated for a two-dimensional disordered system in the presence of a strong perpendicular static magnetic field. The ac-conductivity is calculated numerically from Kubo's linear response theory using a recursive Green's function technique. In the tail of the lowest Landau band, we find a linear frequen

Gi-Yeong Oh

The method of the Peierls substitution in studying the magnetic subband structure of a hexagonal lattice is re-examined. Several errors in the formalism of a couple of recent papers are pointed out and rectified so as to describe the effect of the magnetic field pertinently.

Gi-Yeong Oh

The effects of anisotropic nearest-neighbor (NN) and isotropic next-nearest-neighbor (NNN) hopping integrals on the magnetic subband structure of an electron on a triangular lattice are studied within the tight-binding approximation. A generalized Harper equation that includes both the NN and the NNN hopping terms is first derived. Then, the effects of aniso

V. K. Jindal, K. Dharamvir, Sarbpreet Singh

A simple model based on atom-atom potential has been used to calculate various bulk, structural and thermodynamic properties of pure C_{60} solid by including implicit anharmonicity. The pressure and temperature dependent properties such as bulk modulus, lattice and orientational structure, thermal expansion, phonon frequency shift, Gruneisen parameters, hea

T. Nikuni, M. Oshikawa, A. Oosawa, H. Tanaka

The recent observation [Oosawa et al. J. Phys. : Condens. Matter {\bf 11}, 265 (1999)] of the field-induced Néel ordering in a spin-gap magnetic compound TlCuCl$_3$ is interpreted as a Bose-Einstein Condensation of magnons. A mean-field calculation based on this picture is shown to describe well the temperature dependence of the magnetization. The present sy

Raphael A. Lehrer, David R. Nelson

We provide a self-contained account of the B vs. H constitutive relation near H_c1 in Type II superconductors with various types of quenched random disorder. The traditional Abrikosov result B ~ [ln (H - H_c1)]^{-2}, valid in the absence of disorder and thermal fluctuations, changes significantly in the presence of disorder. Moreover, the constitutive relati

Daniel A. Dale, George Helou, Nancy A. Silbermann, Alessandra Contursi

We report a mid-infrared color and surface brightness analysis of IC 10, NGC 1313, and NGC 6946, three of the nearby galaxies studied under the Infrared Space Observatory Key Project on Normal Galaxies. Images with < 9 arcsecond (170 pc) resolution of these nearly face-on, late-type galaxies were obtained using the LW2 (6.75 mu) and LW3 (15 mu) ISOCAM filter

E. Vesperini, Martin D. Weinberg

We study the internal response of a galaxy to an unbound encounter and present a survey of orbital parameters covering typical encounters in different galactic environments. Overall, we conclude that relatively weak encounters by low-mass interloping galaxies can cause observable distortions in the primaries. The resulting asymmetries may persist long after

M. D. Roberts

Monte Carlo simulations show that the pulse profile of Cherenkov photons measured near the core of an extensive air shower is sensitive to the secondary muon/electron ratio of the cascade. Cherenkov pulses can easily be measured with a single large area mirror viewed by a photomultiplier tube subtending a small field of view (~1 degree). Even for such a simp

H. W. Hartmann, P. J. Wheatley, J. Heise, J. A. Mattei

We report six BeppoSAX X-ray observations of VW Hydri during and after the outburst of Sep 23 1998. The outburst flux is lower than the quiescent flux in the entire observed energy band (0.1-10 keV), in agreement with earlier observations. The X-ray spectra are fitted with two-temperature plasma and cooling flow spectral models. These fits show a clear spect

G. Bertin, G. Lodato

We consider a class of steady-state self-gravitating accretion disks for which efficient cooling mechanisms are assumed to operate so that the disk is self-regulated at a condition of approximate marginal Jeans stability. In an earlier paper, this scenario had been shown to lead naturally, in the absence of a central point mass, to a self-similar solution ch

M. Orlandini, D. Dal Fiume, S. Del Sordo, F. Frontera

We report on a 30 ks observation of the high-mass X-ray binary pulsar OAO1657-415 performed by BeppoSAX on September 1998. The wide band spectrum is well fit by both a cutoff power law, or a power law modified by a high energy cutoff, plus a fluorescence Iron line at 6.5 keV. The two models are statistically equivalent. The inclusion of a cyclotron resonance

Konrad Bernloehr

Atmospheric density profiles as well as several light absorption and scattering processes depend on geographic position and are generally time-variable. Their impact on the atmospheric Cherenkov technique in general (imaging or non-imaging) is investigated. Different density profiles lead to differences in Cherenkov light density of up to 60%. Seasonal varia

W. Hofmann, H. Lampeitl, A. Konopelko, H. Krawczynski

We present analysis techniques to improve the energy resolution of stereoscopic systems of imaging atmospheric Cherenkov telescopes, using the HEGRA telescope system as an example. The techniques include (i) the determination of the height of the shower maximum, which is then taken into account in the energy determination, and (ii) the determination of the l

R. Fux

Self-consistent hybrid N-body and SPH simulations are used to give a new and coherent interpretation of the main features standing out from the HI and CO longitude-velocity observations within the Galactic bar. In particular, the traces of the gas associated to the Milky Way&#39;s dustlanes can be reliably identified and the 3-kpc arm appears as a gaseous st

J. Kataoka, T. Takahashi, F. Makino, S. Inoue

The TeV blazar PKS 2155-304 was monitored with the X-ray satellite ASCA in 1994 May, as part of a multiwavelength campaign from the radio to X-ray bands. At the beginning of the two-day continuous observation, we detected a large flare, where the 2-10 keV flux changed by a factor of 2 on a time scale of 3 x 10^4 sec. During the flare, the increase in the har

T. Yamada, S. Yamazaki, M. Hattori, G. Soucail

We present new high signal-to-noise ratio spectra of the components B and C of the gravitational lensing system MG2016+112. We show that image C displays strong emission lines of Ly$α$, \NV, \CIV, \HeII, and \CIII redshifted to z=3.27, similar to images and B. We examine the emission-line flux ratios in order to put constraints on the lens models as well as

V. V. Vassiliev

Recent observations of the TeV gamma-ray spectra of the two closest active galactic nuclei (AGNs), Markarian 501 (Mrk 501) and Markarian 421 (Mrk 421), by the Whipple and HEGRA collaborations have stimulated efforts to estimate or limit the spectral energy density (SED) of extragalactic background light (EBL) which causes attenuation of TeV photons via pair-

V. Jonauskas

A variation of fundamental constants of physics is proposed in a frame of static universe. It is shown when the velocity of light increases (decreases) the Planck&#39;s constant increases (decreases) and mass of bodies decreases (increases). This variation of constants leads to the variation of dimensions of bodies and the energy levels of atoms, but a fine

S. Eremin, E. Ivanov

We compute the one-loop holomorphic effective action of the massless Cartan sector of N=2 SYM theory in the Coulomb branch, taking into account the contributions both from the charged hypermultiplets and off-diagonal components of the gauge superfield. We use the manifestly supersymmetric harmonic superfields diagram techniques adapted to N=2 supersymmetry w

Jorma Louko, Hans-Juergen Matschull

We formulate and analyze the Hamiltonian dynamics of a pair of massive spinless point particles in (2+1)-dimensional Einstein gravity by anchoring the system to a conical infinity, isometric to the infinity generated by a single massive but possibly spinning particle. The reduced phase space Γ_{red} has dimension four and topology R^3 x S^1. Γ_{red} is analo

S. Wakimoto, R. J. Birgeneau, M. A. Kastner, Y. S. Lee

We report the results of an extensive elastic neutron scattering study of the incommensurate (IC) static spin correlations in La1.95Sr0.05CuO4 which is an insulating spin glass at low temperatures. The present neutron scattering experiments on the same x=0.05 crystal employ a narrower instrumental Q-resolution and thereby have revealed that the crystal has o

D. M. Appleby

The proposal that the interaction between a macroscopic body and its environment plays a crucial role in producing the correct classical limit in the Bohm interpretation of quantum mechanics is investigated, in the context of a model of quantum Brownian motion. It is well known that one of the effects of the interaction is to produce an extremely rapid appro

Rob Clifton, Hans Halvorson

Given a bipartite quantum system represented by a tensor product of two Hilbert spaces, we give an elementary argument showing that if either component space is infinite-dimensional, then the set of nonseparable density operators is trace-norm dense in the set of all density operators (and the separable density operators nowhere dense). This result complemen

Bruce J. King

Parameter lists are presented for speculative muon colliders at center-of-mass energies of 10 TeV and 100 TeV. The technological advances required to achieve the given parameters are itemized and discussed, and a discussion is given of the design goals and constraints. An important constraint for multi-TeV muon colliders is the need to minimize neutrino radi

Bruce J. King

High energy muon colliders, such as the TeV-scale conceptual designs now being considered, are found to produce enough high energy neutrinos to constitute a potentially serious off-site radiation hazard in the neighbourhood of the accelerator site. A general characterization of this radiation hazard is given, followed by an order-of-magnitude calculation for

Bruce J. King

Some of the potential capabilities and design challenges of muon colliders are illustrated using self-consistent collider parameter sets at center of mass energies ranging from 0.1 TeV to 100 TeV.

S. Kalyana rama

We present a simple derivation of an upper bound on the average size of the true vacuum bubbles at the end of inflation, in models of extended inflation type. The derivation uses the inequality that the total energy inside a given volume must be less than its linear dimensions. The above bound is the same as that obtained earlier, by applying the holographic

Matthias R Gaberdiel, Ashoke Sen

The spectrum of open strings on various non-BPS D-brane configurations in type II string theory on a K3 orbifold is analysed. At a generic point in the corresponding moduli space the spectrum of open strings does not have any degeneracy between bosonic and fermionic states. However, there exist special values for these moduli for which many non-BPS D-brane c

Sze-Shiang Feng, Zhi Yao, De-Pin Zhao, De-Si Zang

We evaluate exactly both the non-relativistic and relativistic fermion determinant in 2+1 dimensions in a constant background field at finite temperature. The effect of finite chemical potential is also considered. In both cases, the systems are decoupled into an infinite number of 1+1 fermions by Fourier transformation in the $β$-variable. The total effecti

Sze-Shiang Feng, Guang-Jiong Ni

Using the new regularization and renormalization scheme recently proposed by Yang and used by Ni et al, we analyse the sine-Gordon and sinh-Gordon models within the framework of Gaussian effective potential in D+1 dimensions. Our analysis suffers no divergence and so does not suffer from the manipulational obscurities in the conventional analysis of divergen

Eli Hawkins

It has been proposed that the noncommutative geometry of the &#34;fuzzy&#34; 2-sphere provides a nonperturbative regularization of scalar field theories. This generalizes to compact Kaehler manifolds where simple field theories are regularized by the geometric quantization of the manifold. In order to permit actual calculations and the comparison with other

Xiao-Gang He, German Valencia

The quark-level process $b \to s γ$ has been used extensively to place constraints on new interactions. These same interactions can be further constrained from the enhancement they induce in the quark-level $s \to d γ$ transition, to the extent that the short distance contributions can be separated from the long distance contributions. We parameterize what i

J. J. van der Bij

In the Standard Model the Fermi constant is associated with the vacuum expectation value of the Higgs field $<Φ>$, `the condensate&#39;, usually believed to be a nearly cut-off independent quantity. General arguments related to the `triviality&#39; of $λΦ^4$ theory in 4 space-time dimensions suggest, however, a dramatic renormalization effect in the continuu

Galit Eyal, Yosef Nir

Models with extended quark sector affect the CP asymmetry in the $B\to \psi K_{S}$ decay, $a_{\psi K_{S}}$, in two ways: First, the top-mediated box diagram is not necessarily the only important contribution to $B-\bar{B}$ mixing. Second, the $3\times 3$ CKM matrix is no longer unitary. We analyze the constraints that follow from the CDF measurement, $a_{\ps

Bruce J. King

It is shown that muon decays in straight sections of muon collider rings will naturally produce highly collimated neutrino beams that can be several orders of magnitude stronger than the beams at existing accelerators. We discuss possible experimental setups and give a very brief overview of the physics potential from such beamlines. Formulae are given for t

Bruce J. King

An overview is given of muon collider technology and of the current status of the muon collider research program. The exciting potential of muon colliders for both neutrino physics and collider physics studies is then described and illustrated using self-consistent collider parameter sets at 0.1 TeV to 100 TeV center-of-mass energies.

CLEO Collaboration

We report on a search for D0-D0bar mixing made by a study of the `wrong-sign&#39; process D0 -> K+pi-. The data come from 9.0 fb^-1 of integrated luminosity of e+e- collisions at sqrt{s} approximately 10 GeV produced by CESR and accumulated with the CLEO II.V detector. We measure the time-integrated rate of the `wrong-sign&#39; process D0 -> K+pi-, relative

CLEO Collaboration

We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions. We present preliminary results based on 9.66 million $B\bar{B}$ pairs collected with the CLEO detector. We have made the first observation of the decay $B \to π^+π^-$, with the branching fraction of $Br(B \to π^+ π^-) = (4.7^{+1.8}_{-1.5} \pm 0.6) \times 10

The SLD Collaboration, K. Abe

We present an updated direct measurement of the parity-violating coupling of the Z boson to strange quarks, A_s, derived from the full SLD data sample of approximately 550,000 hadronic decays of Z bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1998. Events with primary strange quarks are tagged by t

J. A. Crittenden

We review topical results on diffractive processes from the experiments H1 and ZEUS at the HERA electron-proton collider. Emphasis is placed on the phenomenological and experimental consequences of the discoveries at HERA for the proposed electron/polarized-ion collider EPIC.

Shunguang Wu, Kaifen He, Zuqia Huang

The spatiotemporal chaos in the system described by a one-dimensional nonlinear drift-wave equation is controlled by directly adding a periodic force with appropriately chosen frequencies. By dividing the solution of the system into a carrier steady wave and its perturbation, we find that the controlling mechanism can be explained by a slaving principle. The

Eiichiro Komatsu, Tetsu Kitayama

We present angular power spectra of the cosmic microwave background radiation anisotropy due to fluctuations of the Sunyaev-Zel&#39;dovich (SZ) effect through clusters of galaxies. A contribution from the correlation among clusters is especially focused on, which has been neglected in the previous analyses. Employing the evolving linear bias factor based on

C. Thompson, R. C. Duncan, P. M. Woods, C. Kouveliotou

We consider the physical implications of the rapid spindown of Soft Gamma Repeater 1900+14, and of the apparent &#34;braking glitch&#34;, ΔP/P = l x 10^-4, that was concurrent with the Aug. 27th giant flare. A radiation-hydrodynamical outflow associated with the flare could impart the required torque, but only if the dipole magnetic field is stronger than ~

Daniela Bigatti, Leonard Susskind

We construct a simple physical model of a particle moving on the infinite noncommutative 2-plane. The model consists of a pair of opposite charges moving in a strong magnetic field. In addition, the charges are connected by a spring. In the limit of large magnetic field, the charges are frozen into the lowest Landau level. Interaction of such particles inclu

V. B. Anikeev

This paper has been withdrawn by the authors.

Andreas Albrecht, Constantinos Skordis

Modern data is showing increasing evidence that the Universe is accelerating. So far, all attempts to account for the acceleration have required some fundamental dimensionless quantities to be extremely small. We show how a class of scalar field models (which may emerge naturally from superstring theory) can account for acceleration which starts in the prese

Asim K. Ray, Saswati Sarkar

Motivated by the recent Super-Kamiokande experiment on atmospheric and solar neutrino oscillation we propose a see-saw model of three generations of neutrinos based on the gauge group $SU(2)_{L}\times U(1)_{Y}$ with discrete symmetries $(S_{3} \times D)$ and three right handed singlet neutrinos so that this model can accommodate the recent Super-Kamiokande d

F. V. Gubarev, M. I. Polikarpov, V. I. Zakharov

We review the physics of the power corrections to the parton model. In the first part, we consider the power corrections which characterize the infrared sensitivity of Feynman graphs when the contribution of short distances dominates. The second part is devoted to the hypothetical power corrections associated with nonperturbative effects at small distances.

J. Goryo

We show that a vortex in a chiral p-wave superconductor, which has the p_{x}+ i p_{y}-wave pairing state and breaks U(1), parity and time reversal symmetry simultaneously, has fractional charge -{n e}/{4} and fractional angular momentum -n^{2}/{16} (n; vorticity). This suggests that the vortex could be anyon and could obey fractional statistics. Electromagne

Mark Dickinson, Christopher Hanley, Richard Elston, Peter R. Eisenhardt

We describe an object in the Hubble Deep Field North with very unusual near-infrared properties. It is readily visible in Hubble Space Telescope NICMOS images at 1.6um and from the ground at 2.2um, but is undetected (with signal-to-noise <~ 2) in very deep WFPC2 and NICMOS data from 0.3 to 1.1um. The f_nu flux density drops by a factor >~ 8.3 (97.7% confiden

Kevork Abazajian, George M. Fuller, Xiangdong Shi

We assess the effects on Big Bang Nucleosynthesis (BBN) of lepton number generation in the early universe resulting from the two-doublet four-neutrino mass/mixing scheme. It has been argued that this neutrino mass/mixing arrangement gives the most viable fit to the existing data. We study full 4 x 4 mixing matrices and show how possible symmetries in these c

Nathan Isgur

I describe four serious defects of a widely discussed pion exchange model for interquark forces: it doesn&#39;t solve the &#34;spin-orbit problem&#34; as advertised, it fails to describe the internal structure of baryon resonances, it leads to disastrous conclusions when extended to mesons, and it is not reasonably connected to the physics of heavy-light sys

Nathan Isgur

I criticize certain conclusions about the physics of hadrons drawn from a &#34;valence QCD&#34; approximation to QCD.

APEX Collaboration, S. Geer

A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on thirteen antiproton decay modes. The results include the first explicit experimental limits on the muonic decay modes of the antiproton, and the first limits on the decay modes e- gamma gamma, and e- omega. The most stringent limit is for the decay mode p

M. Hofmann, J. M. Eisenberg, S. Scherer, M. Bleicher

We investigate the hadronic cooling of a quark droplet within a microscopic model. The color flux tube approach is used to describe the hadronization of the quark phase. The model reproduces experimental particle ratios equally well compared to a static thermal hadronic source. Furthermore, the dynamics of the decomposition of a quark-gluon plasma is investi

M. Hofmann, M. Bleicher, S. Scherer, L. Neise

A microscopic model of deconfined matter based on color interactions between semi-classical quarks is studied. A hadronization mechanism is imposed to examine the properties and the disassembly of a thermalized quark plasma and to investigate the possible existence of a phase transition from quark matter to hadron matter.

Banibrata Mukhopadhyay

People are familiar with quantum mechanical reflection and transmission coefficient. In all those cases corresponding potentials are usually assumed as of constant height and depth. For the cases of varying potential, corresponding reflection and transmission coefficients can be found out using WKB approximation method. But due to change of barrier height, r

Yuri Kondratiev, Jose Luis Silva, Ludwig Streit, Georgi Us

We study the spaces of Poisson, compound Poisson and Gamma noises as special cases of a general approach to non-Gaussian white noise calculus, see \cite{KSS96}. We use a known unitary isomorphism between Poisson and compound Poisson spaces in order to transport analytic structures from Poisson space to compound Poisson space. Finally we study a Fock type str

Yuri Kondratiev, Jose Luis Silva, Ludwig Streit

We give a general approach to infinite dimensional non-Gaussian analysis which generalizes the work \cite{KSWY95}. For given measure we construct a family of biorthogonal systems. We study their properties and their Gel&#39;fand triples that they generate. As an example we consider the measures of Poisson type.

Valeri V. Dvoeglazov

We construct the transversal and longitudinal 4-vector potentials and strengths F^{μν} in the momentum representation on using the second-type 4-spinors recently proposed by Ahluwalia. Questions of relevance of this kind of theories to the correct photon statistics are briefly discussed.

Wen-Fa Lu

Within the framework of the Gaussian wave-functional approach, we investigate the influences of quantum and finite-temperature effects on the Z_2-symmetry(ϕ\to -ϕ) of the (1+1)-dimensional massive sine-Gordon field theory. It is explicitly demonstrated that by quantum effects the Z_2-symmetry can be restored in one region of the parameter space and dynamical

F. V. Gubarev, M. I. Polikarpov, V. I. Zakharov

We review recent speculations on power like corrections in QCD which go beyond the standard Operator Product Expansion. Both the theoretical picture underlying these corrections and phenomenological manifestations are discussed in some detail.

Rukmani Mohanta, Anjan K. Giri, Mohinder P. Khanna, Muneyuki Ishida

Motivated by the observation of the decay B to K* gamma by the CLEO collaboration, we have systematically analyzed the weak radiative decay Lambda_b to Lambda gamma, evaluating the confined effects of quarks in the covariant oscillator quark model. This decay process receives both short distance (electromagnetic penguins at the one loop level) the long dista

Massimo Blasone, Yuan-Xing Gui, Francis Vendrell

We study a new spacetime which is shown to be the general geometrical background for Thermal Field Theories at equilibrium. The different formalisms of Thermal Field Theory are unified in a simple way in this spacetime. The set of time-paths used in the Path Ordered Method is interpreted in geometrical terms.

F. Göhmann, V. E. Korepin

We argue that the square of the norm of the Hubbard wave function is proportional to the determinant of a matrix, which is obtained by linearization of the Lieb-Wu equations around a solution. This means that in the vicinity of a solution the Lieb-Wu equations are non-degenerate, if the corresponding wave function is non-zero. We further derive an action tha

Tetsu Kitayama, Satoru Ikeuchi

The effects of the UV background radiation on the formation of sub-galactic clouds are studied by means of one-dimensional hydrodynamical simulations. The radiative transfer of the ionizing photons due to the absorption by HI, HeI and HeII, neglecting the emission, is explicitly taken into account. We find that the complete suppression of collapse occurs for

J. H. Fan

In this paper, the historical infrared (JHK) data compiled from 22 publications are presented for 3C279 and 4C29.45. Relation between color index and magnitude and between color-color indices are discussed. (J-K) is found closely correlated with (J-H) while (J-H) is almost not correlated with (H-K), which is perhaps due to two facts of (1) (J-K) shows wider

Adam Burrows, M. S. Marley, C. M. Sharp

We identify the pressure--broadened red wings of the saturated potassium resonance lines at 7700 Åas the source of anomalous absorption seen in the near-infrared spectra of Gliese 229B and, by extension, of methane dwarfs in general. This conclusion is supported by the recent work of Tsuji {\it et al.} 1999, though unlike them we find that dust need not be i

A. Ferraz, T. Saikawa, Z. Y. Weng

We consider a model composed of Landau quasiparticle states with patched Fermi surfaces (FS) sandwiched by states with flat FS to simulate the ``cold'' spot regions in cuprates. We calculate the one particle irreducible function and the self-energy up to two-loop order. Using renormalization group arguments we show that in the forward scattering channel the

N. Primozich, T. V. Shahbazyan, I. E. Perakis, D. S. Chemla

We develop a non-equilibrium many-body theory of the coherent femtosecond nonlinear optical response of the Fermi edge singularity. We study the role of the dynamical Fermi sea response in the time-evolution of the pump-probe spectra. The electron-hole correlations are treated nonperturbatively with the time-dependent coupled cluster cxpansion combined with

Peter W. Gorham, Liese van Zee, Stephen C. Unwin, Christopher S. Jacobs

We present Hubble Space Telescope (HST) imagery and photometry of the active galaxy Markarian 421 and its companion galaxy 14 arcsec to the ENE. The HST images indicate that the companion is a morphological spiral rather than elliptical as previous ground--based imaging has concluded. The companion has a bright, compact nucleus, appearing unresolved in the H

C. Bernard, C. DeTar, S. Gottlieb, U. M. Heller

Quantum chromodynamics with two zero-mass flavors is expected to exhibit a phase transition with O(4) critical behavior. Fixing the universality class is important for phenomenology and for facilitating the extrapolation of simulation data to physical quark mass values. Other groups have reported results from lattice QCD simulations with dynamical staggered

Sohrab Ismail-Beigi, T. A. Arias

We report the first ab initio density-functional study of <111> screw dislocations cores in the bcc transition metals Mo and Ta. Our results suggest a new picture of bcc plasticity with symmetric and compact dislocation cores, contrary to the presently accepted picture based on continuum and interatomic potentials. Core energy scales in this new picture are