January 1995 arXiv papers — page 2

M. Boyce, P. J. S. Watson

For over 50 years attempts have been made to explain the properties of nuclear matter in terms of constituent nucleons with very little success. Here we will investigate one class of many possible models, string-flip potential models, in which flux-tubes are connected between quarks (in a gas/plasma) to give a minimal overall field configuration. A general o

M. Bucher, A. S. Goldhaber, N. Turok, .

An inflationary scenario that leads to $Ω_0<1$ today is presented. An epoch of `old&#39; inflation during which the smoothness and horizon problems are solved is followed by a shortened epoch of `new&#39; inflation. Old inflation exits through the nucleation of a single bubble, leading to negative spatial curvature on slices of constant cosmic time. We calcu

Marco Lanzagorta, Graham G. Ross

We reconsider how Yukawa couplings may be determined in terms of a gauge coupling through the infra-red fixed point structure paying particular regard to the rate of approach to the fixed point. Using this we determine whether the fixed point structure of an underlying unified theory may play a significant role in fixing the couplings at the gauge unificatio

G. V. Kraniotis

The phenomenological consequences of the dilaton-type soft supersymmetry breaking terms in the context of the next to minimal supersymmetric standard model are investigated. We always find a very low top quark mass. As a consequence such string vacua are excluded by recent experimental results. The viability of the solution of the $μ$ term through the introd

Bernd A. Kniehl, Michael Spira

We evaluate the two-loop ${\cal O}(α_sG_Fm_t^2)$ correction to the $ZZH$ coupling in the Standard Model by means of a low-energy theorem, assuming that the top quark is much heavier than the Higgs boson. We then construct a heavy-top-quark effective Lagrangian for the $ZZH$ interaction that accommodates the ${\cal O}(G_Fm_t^2)$ and ${\cal O}(α_sG_Fm_t^2)$ co

M. Takizawa, T. Inoue, M. Oka

We study the $K \to 2 π$ decays using the $U_L(3) \times U_R(3)$ version of the Nambu-Jona-Lasinio model with the effective $ΔS = 1$ nonleptonic weak interaction. The $ΔI = {3/2}$ amplitude is in reasonable agreement with experimental data. On the other hand, the calculated $ΔI = {1/2}$ amplitudes strongly depend on the mass of the low-lying scalar-isoscalar

F. del Aguila, M. Cvetic, P. Langacker

The discovery of a new neutral gauge boson $Z&#39;$ with a mass in the TeV region would allow for determination of gauge couplings of the $Z&#39;$ to ordinary quarks and leptons in a model independent way. We show that these couplings in turn would allow us to determine the nature of the extended gauge structure. As a prime example we study the $E_6$ group.

Jose P. Mimoso, David Wands

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state ($p\proptoρ$) in a spatially flat (Bianchi type~I) cosmology. These models approach an isotropic, general relativistic solution as t

R. B. Mann

I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

Sujan Sengupta

The role of the parameter `$a$&#39; associated with the Kerr metric which represents the angular momentum per unit mass of a rotating massive object has been converted into determining the rotationally induced quadrapole electric field outside a rotating massive object with external dipole magnetic field. A comparison of the result with that of the Newtonian

P. B. Wiegmann, A. V. Zabrodin

A class of second order difference (discrete) operators with a partial algebraization of the spectrum is introduced. The eigenfuncions of the algebraized part of the spectrum are polinomials (discrete polinomials). Such difference operators can be constructed by means of $U_q(sl_2)$, the quantum deformation of the $sl_2$ algebra. The roots of polinomials det

P. Zupanovic, A. Bjelis, S. Barisic

Starting from the random phase approximation for the weakly coupled multiband tightly-bounded electron systems, we calculate the dielectric matrix in terms of intraband and interband transitions. The advantages of this representation with respect to the usual plane-wave decomposition are pointed out. The analysis becomes particularly transparent in the long

S. P. Strong

We demonstrate that the hopping of singlet electron pairs between Hubbard chains is relevant in the renormalization group sense if appropriate correlations exist between the chains.

Jakub Zakrzewski

Numerical study of the parametric motion of energy levels in a model system built on Random Matrix Theory is presented. The correlation function of levels&#39; slopes (the so called velocity correlation function) is determined numerically and compared with its limiting analytic form when available. A simple analytic form of the velocity correlation function

I. Guarneri, M. DiMeo

We numerically perform a spectral analysis of a quasi-periodically driven spin 1/2 system, the spectrum of which is Singular Continuous. We compute fractal dimensions of spectral measures and discuss their connections with the time behaviour of various dynamical quantities, such as the moments of the distribution of the wave packet. Our data suggest a close

Lawrence M. Krauss

Big Bang Nucleosynthesis represents perhaps the first, and still perhaps the most powerful particle-astrophysics connection. As such, it should provide an example for other work in this area. I discuss the current status of standard model BBN predictions and constraints, and then argue that the issue of observational systematic uncertainties is the key featu

D. Ricci, G. L. Israel, L. Stella

We present results from the analysis of the two EXOSAT observations of the low mass X-ray binary (LMXRB) 4U1957+11. The 1-20keV spectrum of the source is best fitted by a power law model with exponential cutoff, that provides an approximation of a thermal Comptonisation spectrum. The cutoff energy (~2keV), as well as the X-ray colours, are intermediate betwe

Ian Smail, David W. Hogg, Roger Blandford, Judith G. Cohen

We report the discovery with the Keck telescope of two new multiply-imaged arcs in the luminous X-ray cluster A2219 ($z=0.225$). The brighter arc in the field is red and we use spectroscopic and photometric information to identify it as a $z \sim 1$ moderately star-forming system. The brightness of this arc implies that it is formed from two merging images o

P. C. Hohenberg, J. B, Swift

The nucleation of a lamellar phase from a supercooled homogeneous phase in a fluctuation driven first-order transition is studied, based on a phenomenological free energy due to Brazovskii. The absence of phase coexistence in the corresponding mean-field approximation makes application of the standard droplet theory of homogeneous nucleation problematic. A s

Stephen G. Naculich

Z-strings in the Weinberg-Salam model including fermions are unstable for all values of the parameters. The cause of this instability is the fermion vacuum energy in the Z-string background. Z-strings with non-zero fermion densities, however, may still be stable.

Sandu Popescu

A teleportation method using standard present day optical technology is presented.

I. L. Shapiro

The fourth derivative models for two dimensional gravity are shown to be equivalent to the special version of the nonlinear sigma models coupled to 2d quantum gravity. The reduction consists in the introduction of the auxiliary scalar fields and can be performed in an explicit way for both metric and general metric-dilaton cases. In view of this we can evalu

T. Kobayashi, H-T. Sato

We study quantum deformed $gl(n)$ and $igl(n)$ algebras on a quantum space discussing multi-parametric extension. We realize elements of deformed $gl(n)$ and $igl(n)$ algebras by a quantum fermionic space. We investigate a map between deformed $igl(2)$ algebras of our basis and other basis.

C. Wetterich

We propose a new method for an analytical, non-perturbative computation of effective quark interactions from QCD. It is based on an exact flow equation which describes the scale dependence of the effective average action for quarks in presence of gluons.

D. Boyanovsky, David E. Brahm, A. Gonzalez-Ruiz, R. Holman

We solve the equations of motion for a scalar field with domain wall boundary conditions in a Friedmann-Robertson-Walker (FRW) spacetime. We find (in agreement with Basu and Vilenkin) that no domain wall solutions exist in de Sitter spacetime for h = H/m >= 1/2, where H is the Hubble parameter and m is the scalar mass. In the general FRW case we develop a sy

E. M. Henley, W-Y. P. Hwang, L. S. Kisslinger

We use QCD sum rules to obtain the weak parity-violating pion-nucleon coupling constant $f_{πNN}$. We find that $f_{πNN}\approx 3\times 10^{-8}$, up to an order of magnitude smaller than the ``best estimates&#34; based on quark models. This result follows from the cancellation between perturbative and nonperturbative QCD processes not found in quark models,

Jorge G. Hirsch

The pseudo SU(3) approach is used to describe low lying states and BE(2) intensities of rare earth and actinide nuclei which are double beta decay candidates. The double beta half lives of some of these nuclei to the ground and excited states of the final ones are evaluated for both the two and zero neutrino emitting modes. The existence of selection rules w

Jorge G. Hirsch, Octavio Castaños, Peter O. Hess, Osvaldo Civitarese

The pseudo SU(3) model is used to study the double beta decay of Nd150 to the ground and excited states of Sm150 . Low lying collective excitations of Sm150 and its BE(2) intensities are well reproduced. Expressions for the two neutrino double beta decay to excited states are developed and used to describe the decay of Nd150 . The existence of selection rule

Octavio Casta~nos, Jorge G. Hirsch, Peter O. Hess. To be published in Proc. CAM94 Phys. Meeting, AIP Press

The pseudo-spin symmetry is reviewed. A mapping that produces the separation of the total angular momentum into pseudo-orbital and pseudo-spin degrees of freedom is discussed, together with the analytic transformations that take us from the normal parity space to the eigenstates of a pseudo-oscillator with one quanta less. The many-particle version of the un

Claude Laflamme

We characterize winning strategies in various infinite games involving filters on the natural numbers in terms of combinatorics or structural properties of the given filter. These generalize several ultrafilter games of Galvin.

Claude Laflamme

We prove various results on the notion of ordinal ultrafiters introduced by J. Baumgartner. In particular, we show that this notion of ultrafilter complexity is independent of the more familiar Rudin-Keisler ordering.

G. Modanese

By means of general kinematical arguments, the lifetime $τ$ of a graviton of energy $E$ for decay into gravitons is found to have the form $τ^{-1} = \frac{1}{EG} \sum_{j=1,2,...} c_j (ΛG)^j$. Some recent, preliminary results of non perturbative simplicial quantum gravity are then employed to estimate the effective values of $G$ and $ΛG$. It turns out that a

C. G. Beneventano, E. M. Santangelo

We study the connection between $ζ$- and cutoff-regularized Casimir energies for scalar fields. We show that, in general, both regularization schemes lead to divergent contributions, and to finite parts which do not coincide. We determine the relationships among the various coefficients appearing in one approach and the other. As an application, we discuss t

Jan C. Plefka

An integral form of the discrete superloop equations for the supereigenvalue model of Alvarez-Gaume, Itoyama, Manes and Zadra is given. By a change of variables from coupling constants to moments we find a compact form of the planar solution for general potentials. In this framework an iterative scheme for the calculation of higher genera contributions to th

J. Loeffelholz, G. Morchio, F. Strocchi

The QED(0+1) model describing a quantum mechanical particle on a circle with minimal electromagnetic interaction and with a potential -M cos(phi - theta_M), which mimics the massive Schwinger model, is discussed as a prototype of mechanisms and infrared structures of gauge quantum field theories in positive gauges. The functional integral representation disp

R. D. Peccei, K. Wang

We present a reanalysis of the allowed region in the $ρ- η\,$ plane of the CKM matrix, which follows from our present knowledge of the theoretical and experimental parameters associated with quark mixing and CP violation. Besides providing updated expectations for the angles of the unitarity triangle, this reanalysis predicts a range of allowed values for th

Gia Dvali, Goran Senjanovic

We show that spontaneous breaking of discrete or continuous symmetries does not necessarily imply either symmetry restoration or the thermal production of defects at high temperature (at least up to $T \sim M_{Planck}$). This may imply that there is no domain wall problem. As an example we show how this applies to the Peccei-Quinn scenario.

R. J. Furnstahl, Hua-Bin Tang, Brian D. Serot

A relativistic hadronic model for nuclear matter and finite nuclei, which incorporates nonlinear chiral symmetry and broken scale invariance, is presented and applied at the one-baryon-loop level to finite nuclei. The model contains an effective light scalar field that is responsible for the mid-range nucleon--nucleon attraction and which has anomalous scali

R. C. Verma, M. P. Khanna

According to the Coleman-Glashow null theorem if all the symmetry breaking effects belong to the same regular representation (octet in the case of SU(3) and {\bf 15} in the case of SU(4)) and are generated in a tadpole type mechanism, the strangeness changing (charm changing) weak transitions generated through the S$_{6}$ (S$_{9}$) tadpole must vanish. Explo

V. Bernard, N. Kaiser, Ulf-G. Meißner

We review the implications of the spontaneous chiral symmetry breaking in QCD for processes involving one, two or more nucleons.

Chr. V. Christov, K. Goeke, M. Polyakov

We study the pseudoscalar, vector and axial current correlation functions in SU(2)-NJL model with scalar and vector couplings. The correlation functions are evaluated in leading order in number of colors $N_c$. As it is expected in the pseudoscalar channel pions appear as Goldstone bosons, and after fixing the cutoff to reproduce the physical pion decay cons

Ken-ichi Hikasa, Yumi Nakamura

Supersymmetric relations between dimensionless couplings receive finite correction at one-loop when supersymmetry is broken softly. We calculate the $O(α_s)$ correction to the squark decay width to a quark and an electroweak gaugino, which is found to be nonvanishing. Logarithmic correction appears when the gluino is heavy.

J. Kodaira

We review the basic aspects of the perturbative QCD based on the operator product expansion to analyze the nucleon structure functions in a pedagogical way. We explain the non-trivial relation between the QCD results and the parton model especially to understand the polarized nucleon structure functions which deserve much attentions in recent years.

M. Wingate, T. DeGrand, S. Collins, U. M. Heller

In this work we present lattice calculations of the masses of P-wave mesons using Monte Carlo simulations. Our valence fermions are defined by the Wilson action. Our gauge fields are generated with both dynamical staggered fermions at a lattice coupling $β\equiv 6/g^2=5.6$ for sea quark masses of $am_q=0.010$ and 0.025, and in the quenched approximation at $

ZEUS Collaboration

Charged particle production has been measured in Deep Inelastic Scattering (DIS) events using the ZEUS detector over a large range of $Q^2$ from 10 to $1280 {\rm\ GeV}^2$. The evolution with $Q$ of the charged multiplicity and scaled momentum has been investigated in the current fragmentation region of the Breit frame. The data are used to study QCD \linebre

Matej Pavsic

It is shown that a relativistic (i.e. a Poincar{\&#39; e} invariant) theory of extended objects (called p-branes) is not necessarily invariant under reparametrizations of corresponding $p$-dimensional worldsheets (including worldlines for $p = 0$). Consequnetly, no constraints among the dynamical variables are necessary and quantization is straightforward. A

Ralf. D Hecht

We discuss two expressions for the conserved quantities (energy momentum and angular momentum) of the Poincaré Gauge Theory. We show, that the variations of the Hamiltonians, of which the expressions are the respective boundary terms, are well defined, if we choose an appropriate phase space for asymptotic flat gravitating systems. Furthermore, we compare th

Tevian Dray, Corinne A. Manogue, Robin W. Tucker

We show that, contrary to recent criticism, our previous work yields a reasonable class of solutions for the massless scalar field in the presence of signature change.

S. A. Tomas

We study by photoacoustic spectroscopy the band--gap shift effect of CdS films. The CdS films were grown by chemical bath deposition and exposed to different annealing atmospheres over a range of temperature in which the sample structure is observed to change. We show the band--gap evolution as a function of temperature of thermal annealing and determine the

Marshall Onellion

We report on magnetization, c-axis and ab-plane resistivity, critical current, electronic band structure and superconducting gap properties. Bulk measurements and photoemission data were taken on similar samples.

C. -T. Gottstein, R. F. Werner

We set up a general structure for the analysis of ``frustration-free ground states&#39;&#39;, or ``zero-energy states&#39;&#39;, i.e., states minimizing each term in a lattice interaction individually. The nesting of the finite volume ground state spaces is described by a generalized inductive limit of observable algebras. The limit space of this inductive s

M. A. Zwaan, J. M. van der Hulst, W. J. G. de Blok, S. S. McGaugh

We present the B band Tully-Fisher relation for Low Surface Brightness (LSB) galaxies. These LSB galaxies follow the same Tully-Fisher relation as normal spiral galaxies. This implies that the mass-to-light ratio (M/L) of LSB galaxies is typically a factor of 2 larger than that of normal galaxies of the same total luminosity and morphological type. Since the

T. J. Davidge, W. E. Harris

We have used the CFHT REDEYE infrared camera to obtain deep J and K&#39; images of four fields in the globular cluster M13. The composite K, J-K color-magnitude diagram (CMD) extends from the upper red giant branch (RGB) to 2 magnitudes below the main sequence turn-off (MSTO). Selected [Fe/H]~ -1.6 isochrones from Bergbusch & VandenBerg (1992, ApJS, 81, 163)

J. Greiner, M. Tavani, T. Belloni

The PSR B1259--63 system contains a 47 ms radio pulsar in a highly eccentric binary with a Be-star companion. Strongly time variable X-ray emission was reported from this system as the pulsar was near apastron in 1992-early 1993. The variability was primarily deduced from an apparent non-detection of the \psr system during a first pre-apastron \ros observati

Steven J. Sturner

We present results of a model for the energetics of electrons accelerated by the large electric fields generated by a rotating highly magnetized neutron star. The energy loss mechanisms we consider in our calculations include magnetic Compton scattering of thermal x-ray photons, triplet pair production, and curvature radiation emission. The electron accelera

JM Figueroa-O&#39;Farrill, S Stanciu

We point out that the recent proof of the Kupershmidt-Wilson theorem by Cheng and Mas-Ramos is underpinned by the Lie-Poisson property of the second Gel&#39;fand-Dickey bracket. The supersymmetric Kupershmidt-Wilson theorem is also proved along these same lines. Finally we comment on the possible repercussions in the problem of the coproduct for W-algebras.

J. Bagger, K. Matchev, D. Pierce

We compute the full set of weak-scale gauge and Yukawa threshold corrections in the minimal supersymmetric standard model, and use them to study the effects of the supersymmetric particle spectrum on gauge and Yukawa coupling unification.

Bernd Stoetzel

Some aspects of two-dimensional gravity coupled to matter fields, especially to the Sine-Gordon-model are examined. General properties and boundary conditions of possible soliton-solutions are considered. Analytic soliton-solutions are discovered and the structure of the induced space-time geometry is discussed. These solutions have interesting features and

J. R. Forshaw, M. G. Ryskin

The diffractive process $γp\to V + X$ (where $V$ is a vector meson and $X$ results from the dissociation of the proton) is studied. In particular, we consider the region of large momentum transfer (i.e. $|t|\ggΛ_{QCD}^2$) and large centre-of-mass (CM) energy, $s$. The asymptotic $(s \to \infty, s/|t|\gg 1$) behaviour is derived from the BFKL equation and com

T. M. Samols

The problem of obtaining a realistic, relativistic description of a quantum system is discussed in the context of a simple (light-cone) lattice field theory. A natural stochastic model is proposed which, although non-local, is relativistic (in the appropriate lattice sense), and which is operationally indistinguishable from the standard quantum theory. The g

Thomas NATTERMANN, Stefan SCHEIDL, Sergey E. KORSHUNOV, Mai Suan LI

We show, that the 2D XY-model with random phase shifts exhibits for low temperature and small disorder a phase with quasi-long-range order, and that the transition to the disordered phase is {\it not} reentrant. These results are obtained by heuristic arguments, an analytical renormalization group calculation, and a numerical Migdal-Kadanoff renormalization

A. I. Bugrij, V. N. Shadura

In this paper we construct the exact representation of the Ising partition function in the form of the $ SL_q(2,R)$-invariant functional integral for the lattice free $(l,q)$-fermion field theory ($l=q=-1$). It is shown that the $(l,q)$-fermionization allows one to re-express the partition function of the eight-vertex model in external field through function

A. Boumenir, R. Carroll

A general construction of transmutation operators is developed for selfadjoint operators in Gelfand triples. Theorems regarding analyticity of generalized eigenfunctions and Paley-Wiener properties are proved.

Maurizio Consoli, Fernando Ferroni

We show that the present experimental LEP average R=Γ_h/Γ_l= 20.795 +- 0.040 is not unambiguous due to the presence of substantial systematic effects which cannot be interpreted within gaussian statistics. We find by Montecarlo simulation that the C.L. of the original LEP sample is only 3.8 \cdot 10^{-4}. We suggest that a reliable extimate of the true R-val

Asher Peres

If a physical system contains a single particle, and if two distant detectors test the presence of linear superpositions of one-particle and vacuum states, a violation of classical locality can occur. It is due to the creation of a two-particle component by the detecting process itself.

A. Simoni, A. Stern, I. Yakushin

We write down the Poisson structure for a relativistic particle where the Lorentz group does not act canonically, but instead as a Poisson-Lie group. In so doing we obtain the classical limit of a particle moving on a noncommutative space possessing $SL_q(2,C)$ invariance. We show that if the standard mass shell constraint is chosen for the Hamiltonian funct

Daniel S. Freed

Lecture notes from the 1994 CRM-CAP Summer School ``Particles and Fields &#39;94&#39;&#39;. Covers material written elsewhere in a more leisurely fashion, including many exercises. Describes derivation of quantum groups from the Chern-Simons lagrangian for the case of a finite gauge group.

R. Barbier, J. Meyer, M. Kibler

A nonrigid rotor model is developed from the two-parameter quantum algebra $U_{qp}({\rm u}_2)$. [This model presents the $U_{qp}({\rm u}_2)$ symmetry and shall be referred to as the qp-rotor model.] A rotational energy formula as well as a qp-deformation of E2 reduced transition probabilities are derived. The qp-rotor model is applied (through fitting proced

E. Hernandez, M. J. Gillan

An algorithm for first-principles electronic structure calculations having a computational cost which scales linearly with the system size is presented. Our method exploits the real-space localization of the density matrix, and in this respect it is related to the technique of Li, Nunes and Vanderbilt. The density matrix is expressed in terms of localized su

Tomasz Dubejko

We use recent advances in circle packing theory to develop a constructive method for the approximation of an analytic function $F:Ω\to \bold C$ by circle packing maps providing we have only been given $Ω$, $|F&#39;|\big|_Ω$, and the set of critical points of $F$. This extends the earlier result of Ithiel Carter and Burt Rodin [CR] for $F$ with no critical po

Wulf Boettger, Henning Wissowski, Hans A. Kastrup

The Hamilton--Jacobi formalism generalized to 2--dimensional field theories according to Lepage&#39;s canonical framework is applied to several covariant real scalar fields, e.g. massless and massive Klein--Gordon, Sine--Gordon, Liouville and $ϕ^4$ theories. For simplicity we use the Hamilton--Jacobi equation of DeDonder and Weyl. Unlike mechanics we have to

V. Barger, Kingman Cheung, T. Han, R. J. N. Phillips

We point out that the ratio of $W^+ W^- \to W^+ W^-$ and $W^+W^- \to ZZ$ cross sections is a sensitive probe of the dynamics of electroweak symmetry breaking, in the CM energy region $\sqrt {s_{\rm ww}^{}} \agt 1$~TeV where vector boson scattering may well become strong. We suggest ways in which this ratio can be extracted at a 1.5 TeV $e^+e^-$ linear collid

T. Woehrmann, H. Fraas

We examine for representative gaugino-higgsino mixing scenarios slepton-neutralino and slepton-chargino production in deep inelastic ep-scattering at $\sqrt{s}=1.8$ TeV. We find sneutrino-chargino production to be the dominant process with cross sections more than one order of magnitude bigger than those for slepton-squark production. Also for associated pro

Eric Braaten, Agustin Nieto

An effective field theory approach is developed for calculating the thermodynamic properties of a field theory at high temperature $T$ and weak coupling $g$. The effective theory is the 3-dimensional field theory obtained by dimensional reduction to the bosonic zero-frequency modes. The parameters of the effective theory can be calculated as perturbation ser

H. Heiselberg

The formation rate of quark matter droplets in neutron stars is calculated from a combination of bubble formation rates in cold degenerate and high temperature matter. Nuclear matter calculations of the viscosity and thermal conductivity are applied. Results show that droplets form only in the core of neutron stars shortly after supernova collapse, where pre

P. J. Rijken, W. L. van Neerven

We investigate the effect of heavy flavor contributions to vector boson ($V$ = $γ$, $Z$, $W$) production which is described by the Drell-Yan mechanism. All reactions with bottom and top quarks ($Q_i$ = $b$, $t$) in the final state, like $q_1 + \bar{q}_2\rightarrow V + Q_1 + \bar{Q}_2$ and $g + g\rightarrow V + Q_1 + \bar{Q}_2$, are considered. This study als

Don Colladay, Alan Kostelecky

The issue of testing CPT invariance at a $B$ factory is considered. We present asymmetries that permit a clean extraction of quantities parametrizing direct and indirect CPT violation, using information from $Υ(4S)$ decay via coherent $B_d\overline{B_d}$ pairs into various final states. Estimates are given of the bounds on CPT violation that could be obtaine

Marek Pawlowski, Ryszard Raczka

A model for strong, electroweak and gravitational interactions based on the local symmetry group $G=SU(3)\times SU(2)_{L}\times U(1)\times C$ where $C$ is the local conformal symmetry group is proposed. The natural minimal $G$-invariant form of total lagrangian is postulated. It contains all Standard Model fields and the gravitational interaction, however th

M. Anselmino, A. Efremov, E. Leader

Comprehensive review paper on the theory and phenomenology of polarized deep inelastic scattering, to appear in Physics Reports

Hiroyuki KAWAMURA, Tsuneo UEMATSU

We discuss the possible target mass corrections in the QCD analysis of nucleon&#39;s spin-dependent structure functions measured in the polarized deep-inelastic leptoproduction. The target mass correction for the QCD Bjorken sum rule is obtained from the Nachtmann moment and its magnitude is estimated employing positivity bound as well as the experimental da

Yoshiaki Yasui

We discuss the spin-dependent structure function $g_2(x,Q^2)$ in the framework of the operator product expansion. It is noted that the anomalous dimensions and coefficient functions for the twist-3 gluon-field-dependent operators depend on the choice of the operator basis. The role played by the operators proportional to the equation of motion is clarified.

Zheng Huang

The current theoretical understanding of disoriented chiral condensate is briefly reviewed. I discuss the basic idea, the formation mechanism and experimental signatures of DCC in high energy collisions.

Gerard Jungman, Marc Kamionkowski

We calculate the flux of cosmic gamma rays expected {}from the annihilation of neutralinos in the Galactic halo. Our calculation of the annihilation cross section to two photons improves the existing calculations by inclusion of exact one-loop diagrams for the amplitudes involving Higgs boson and chargino states as well as those involving fermion and sfermio

U. Kerres, G. Mack, G. Palma

We propose the study of the phase transition in the scalar electroweak theory at finite temperature by a two - step method. It combines i) dimensional reduction to a 3-dimensional {\it lattice\/} theory via perturbative blockspin transformation, and ii) either further real space renormalization group transformations, or solution of gap equations, for the 3d

ZEUS Collaboration

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $γp$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show

Sabine Kluske

For arbitrary high order of the field equation one can always find examples where the de Sitter space-time is an attractor solution in the set of the spatially flat Friedmann-Robertson-Walker models.

M. D. Maia, E. M. Monte

The compatibility between the general relativity and the mathematical property that the space-times are embedded manifolds are further examined. In particular we study the uniqueness of the signature of the embedding space for a given space-time. The interpretation of the twisting vector as a gauge potential is also implemented.

Michael Kamal, Ziad H. Musslimani, Assa Auerbach.

We study effects of local electron interactions on the persistent current of one dimensional disordered rings. For different realizations of disorder we compute the current as a function of Aharonov-Bohm flux to zeroth and first orders in the Hubbard interaction. We find that the persistent current is {\em enhanced} by onsite interactions. Using an avoided l

Stefan SCHEIDL

In this article the one-dimensional, overdamped motion of a classical particle is considered, which is coupled to a thermal bath and is drifting in a quenched disorder potential. The mobility of the particle is examined as a function of temperature and driving force acting on the particle. A framework is presented, which reveals the dependence of mobility on

C. E. Creffield, E. G. Klepfish, E. R. Pike, Sarben Sarkar

The singular value decomposition technique is used to reconstruct the electronic spectral weight function for a half-filled Hubbard model with on-site repulsion $U=4t$ from Quantum Monte Carlo data. A two-band structure for the single-particle excitation spectrum is found to persist as the lattice size exceeds the spin-spin correlation length. The observed b

A. I. Liechtenstein, I. I. Mazin, O. K. Andersen

It is usually believed that the spin-fluctuation mechanism for high-temperature superconductivity results in d-wave pairing, and that it is destructive for the conventional phonon-mediated pairing. We show that in bilayer materials, due to nearly perfect antiferromagnetic spin correlations between the planes, the stronger instability is with respect to a sup

J. Bricmont, A. Kupiainen, J. Xin

We study the initial value problem of the thermal-diffusive combustion system: $u_{1,t} = u_{1,x,x} - u_1 u^2_2, u_{2,t} = d u_{2,xx} + u_1 u^2_2, x \in R^1$, for non-negative spatially decaying initial data of arbitrary size and for any positive constant $d$. We show that if the initial data decays to zero sufficiently fast at infinity, then the solution $(

S. Cristiani, S. D&#39;Odorico, A. Fontana, E. Giallongo

The spectrum of the Q0055-269 ($z=3.66$) has been observed at the resolution of 14 km s$^{-1}$ in the wavelength interval 4750--6300 Å. The statistical distribution of the Doppler parameter for the Ly$_α$ lines is peaked at $b\simeq 23$ km s$^{-1}$. The column density distribution is described by a power-law with a break at $\log N_{HI} \simeq 14.5$. Signifi

C. Alcock, R. A. Allsman, T. S. Axelrod, D. P. Bennett

We have monitored 8.6 million stars in the Large Magellanic Cloud for 1.1 years and have found 3 events consistent with gravitational microlensing. We place strong constraints on the Galactic halo content in the form of compact lensing objects in the mass range $10^{-4} \msun$ to $10^{-1} \msun$. Three events is fewer than expected for a standard spherical h

A. A. Golubov, I. I. Mazin

We show that in a superconductor where two or more bands cross the Fermi level it is possible, in the framework of the conventional (s-wave) BCS theory, that the sign of the superconducting gap is different on the different sheets of the Fermi surface. At least one of two conditions has to be satisfied: (1) The interband pairing interaction is weaker than th

Alex J. Feingold, John F. X. Ries, Michael D. Weiner

The usual spinor construction from one fermion yields four irreducible representations of the Virasoro algebra with central charge $c = 1/2$. The Neveu-Schwarz (NS) sector is the direct sum of an $h = 0$ and an $h = 1/2$ module, and the Ramond (R) sector is the direct sum of two copies of an $h = 1/16$ module. In addition to the fundamental fermions, which r

E. Ruiz Arriola, L. L. Salcedo

We consider the extended SU(3) Nambu and Jona-Lasinio model with explicit vector couplings in the presence of external fields. We study the chiral anomaly in this model and its implications on the properties of the nucleon described as a chiral soliton of three valence quarks bounded in mesonic background fields. For the model to reproduce the QCD anomaly it

T. Kawano, Y. Kikukawa

Taking into account of the boundary condition in the fifth direction which is derived from the lattice Wilson fermion, we develop a theory of five-dimensional fermion with kink-like and homogeneous masses in finite extent of the fifth dimension. The boundary state wave functions are constructed explicitly and the would-be vacuum overlap is expanded by using

K. C. K. Chan, R. B. Mann

Exact black hole and cosmological solutions are obtained for a special two-dimensional dilaton-spectator ($ϕ-ψ$) theory of gravity. We show how in this context any desired spacetime behaviour can be determined by an appropriate choice of a dilaton potential function $V(ϕ)$ and a ``coupling function&#39;&#39; $l(ϕ)$ in the action. We illustrate several black

Kin-Wang Ng, A. D. Speliotopoulos

We present a theoretical calculation of the variance $ΔC_l$ of the CMB anisotropy power spectrum $\langle C_l\rangle$ caused by gravitational waves based on quantum field theory in an inflationary cosmology.