February 1998 arXiv papers — page 12

Juergen Schaffner-Bielich, Norman K. Glendenning

The equation of state and the properties of neutron stars are studied for a phase transition to a charged kaon condensate. We study the mixed phase by using Gibbs condition with comparison to the hitherto applied Maxwell construction. Implications for kaon condensation and for the mass-radius relation of condensed neutron stars are examined.

Holly Bernstein, Dave Witte

For i = 1,2, let Gamma_i be a lattice in a simply connected, solvable Lie group G_i, and let X_i be a connected Lie subgroup of G_i. The double cosets Gamma_igX_i provide a foliation F_i of the homogeneous space Gamma_i\G_i. Let f be a continuous map from Gamma_1\G_1 to Gamma_2\G_2 whose restriction to each leaf of F_1 is a covering map onto a leaf of F_2. I

János Kollár

This is the third of a series of papers studying real algebraic threefolds, but the methods are mostly independent from the previous two. Let $f:X\to S$ be a map of a smooth projective real algebraic 3-fold to a surface $S$ whose general fibers are rational curves. Assume that the set of real points of $X$ is an orientable 3-manifold $M$. The aim of the pape

Lev A. Borisov

We construct explicitly regular sequences in the semigroup ring $R=\CC[K]$ of lattice points of the graded cone $K$. We conjecture that the quotients of $R$ by these sequences describe locally string-theoretic cohomology of a toroidal singularity associated to $K$. As a byproduct, we give an elementary proof of the result of Hochster that semigroup rings of

Tomohide Terasoma

In this paper, we prove the l-independence of monodromy weight filtration for a geometrically smooth variety over an equicharacteristic local field. We also prove the l-independence for the geometric monodromy representation on the associated graded module of weight monodromy filtration.

Klaus-Dieter Kirchberg

A closed spin Kähler manifold of positive scalar curvature with smallest possible first eigenvalue of the Dirac operator is characterized by holomorphic spinors. It is shown that on any spin Kähler-Einstein manifold each holomorphic spinor is a finite sum of eigenspinors of the square of the Dirac operator. Vanishing theorems for holomorphic spinors are prov

Vadim Schechtman

This note consists of two parts. Part I is an exposition of (a part of) the V.Drinfeld's letter, [D]. The sheaf of algebras of polyvector fields on a Calabi-Yau manifold, equipped with the Schouten bracket, admits a structure of a Batalin-Vilkovisky algebra. This fact was probably first noticed by Z.Ran, [R]. Part II is devoted to some generalizations of

F. Lenz, M. Thies

A study of the center symmetric phase of SU(2) Yang Mills theory is presented. Realization of the center symmetry is shown to result from non-perturbative gauge fixing. Dictated by the center symmetry, this phase exhibits already at the perturbative level confinement like properties. The analysis is performed by investigating the dynamics of the Polyakov loo

H. Garcia-Compean, O. Obregon, C. Ramirez

Strong-weak duality invariance can only be defined for particular sectors of supersymmetric Yang-Mills theories. Nevertheless, for full non-Abelian non-supersymmetric theories, dual theories with inverted couplings, have been found. We show that an analogous procedure allows to find the dual action to the gauge theory of gravity constructed by the MacDowell-

F. Lesage, H. Saleur, P. Simonetti

We discuss in this paper the behaviour of minimal models of conformal theory perturbed by the operator $Φ_{13}$ at the boundary. Using the RSOS restriction of the sine-Gordon model, adapted to the boundary problem, a series of boundary flows between different set of conformally invariant boundary conditions are described. Generalizing the "staircase"

M. S. Berger, B. L. Winer

The top quark will be extensively studied at future muon colliders. The threshold cross section can be measured precisely, and the small beam energy spread is especially effective at making the measurement useful. We report on all the activities of the top quark working group, including talks on top quark physics at other future colliders.

Hiroshi Nunokawa

This talk summarizes our recent work which studied the impact of resonant neutrino conversion induced by some non-standard neutrino properties beyond mass and mixing, such as neutrino magnetic moment, lepton-flavor non-universality as well as flavor changing neutral current interactions in SUSY models with broken R parity, on supernova physics.

Duane A. Dicus, David J. Muller, Satyanarayan Nandi

We investigate the effect that a charged Higgs decay channel for the top quark has on the signature for top quark pair production at the Tevatron. The branching ratios for the various multijet and multilepton final states arising from top pair production are obtained for a wide range of values for tangent beta and the charged Higgs boson mass. In addition, t

J. W. F. Valle

In this talk I discuss the motivations for supersymmetry, focussing on models with broken R-parity and lepton number. After describing the main theoretical features of these models, I discuss some of the signals expected at colliders such as Tevatron, LEP II, NLC and LHC.

F. Parodi, P. Roudeau, A. Stocchi

A review of the current status of the Cabibbo-Kobayashi-Maskawa matrix V_CKM is presented. This paper contains an update of the results published in hep-ph/9711261. Values of the parameters entering into the constraints, which restrict the range for rho and eta parameters, include recent measurements given at 1997 Summer Conferences and progress obtained by

Lev Kofman

It is assumed that during inflation, all energy was contained in a slow-rolling inflaton field $ϕ$. The particles constituting the Universe are created due to interactions with the field $ϕ$ coherently oscillating after inflation. The leading channel of the particle production would be the non-perturbative regime of parametric resonance, preheating. Some of

M. Alford, K. Rajagopal, F. Wilczek

We study finite density QCD in an approximation in which the interaction between quarks is modelled on that induced by instantons. We sketch the mechanism by which chiral symmetry restoration at finite density occurs in this model. At all densities high enough that the chirally symmetric phase fills space, we find that color symmetry is broken by the formati

MILC Collaboration, T. DeGrand

I have performed scaling tests using quenched spectroscopy of a family of fermion actions which have a hypercubic kinetic term, gauge connections built of smeared links, and an anomalous magnetic moment term. These actions show improved rotational invariance compared to the standard Wilson action and to the tadpole-improved clover action. Hyperfine splitting

Martin Lüscher

It is shown that the Ginsparg-Wilson relation implies an exact symmetry of the fermion action, which may be regarded as a lattice form of an infinitesimal chiral rotation. Using this result it is straightforward to construct lattice Yukawa models with unbroken flavour and chiral symmetries and no doubling of the fermion spectrum. A contradiction with the Nie

H. S. Egawa, N. Tsuda, T. Yukawa

The statistical properties of dynamically triangulated manifolds (DT mfds) in terms of the geodesic distance have been studied numerically. The string susceptibility exponents for the boundary surfaces in three-dimensional DT mfds were measured numerically. For spherical boundary surfaces, we obtained a result consistent with the case of a two-dimensional sp

A. Di Giacomo

The evidence is reviewed for the mechanism of colour confinement in QCD by dual superconductivity of the ground state, i.e. by condensation of monopoles.

Vladimir S. Mashkevich

This paper is a sequel to the series of papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046, gr-qc/9704033, gr-qc/9704038, gr-qc/9708014, gr-qc/9802016]. The problem of the meaning of objective a priori probability for individual random trials without repetition is considered. A sequence of such trials, namely quantum jumps, is

Bernard F Schutz

I give a brief introduction to the problem of detecting gravitational radiation from neutron stars. After a review of the mechanisms by which such stars may produce radiation, I consider the different search strategies appropriate to the different kinds of sources: isolated known pulsars, neutron stars in binaries, and unseen neutron stars. The problem of an

M. Letz, R. J. Gooding

Deviations from Fermi liquid behavior are well documented in the normal state of the cuprate superconductors, and some of these differences are possibly related to pre-formed pairs appearing at temperatures above T_c. In order to test these ideas we have investigated the attractive Hubbard model within a self-consistent, conserving ladder approximation. In t

M. Letz, R. J. Gooding

The attractive Hubbard model on a 2-D square lattice is studied at low electronic densities using the ladder approximation for the pair susceptibility. This model includes (i) the short coherence lengths known to exist experimentally in the cuprate superconductors, and (ii) two-particle bound states that correspond to electron pairs. We study the quasipartic

C. Pich, A. P. Young

We study the quantum phase transition in the two-dimensional random Ising model in a transverse field by Monte Carlo simulations. We find results similar to those known analytically in one-dimension: the dynamical exponent is infinite and, at the critical point, the typical correlation function decays with a stretched exponential dependence on distance. Away

M. Letz, R. J. Gooding

We have investigated the attractive Hubbard model in the low density limit for the 2D square lattice using the ladder approximation for the vertex function in a self-consistent, conserving formulation. In the parameter region where the on-site attraction is of the order of the bandwidth, we found no evidence of a pseudo gap. Further, we have observed that th

Yan V. Fyodorov, Yoram Alhassid

Using the random matrix description of open quantum chaotic systems we calculate in closed form the universal autocorrelation function and the probability distribution of the total photodissociation cross section in the regime of quantum chaos.

H. Rieger, N. Kawashima

A cluster algorithm formulated in continuous (imaginary) time is presented for Ising models in a transverse field. It works directly with an infinite number of time-slices in the imaginary time direction, avoiding the necessity to take this limit explicitly. The algorithm is tested at the zero-temperature critical point of the pure two-dimensional (2d) trans

Nigel Goldenfeld, Alan McKane, Qing Hou

We investigate the use of renormalisation group methods to solve partial differential equations (PDEs) numerically. Our approach focuses on coarse-graining the underlying continuum process as opposed to the conventional numerical analysis method of sampling it. We calculate exactly the coarse-grained or `perfect' Laplacian operator and investigate the nu

S. Wiseman, E. Domany

The distributions $P(X)$ of singular thermodynamic quantities in an ensemble of quenched random samples of linear size $l$ at the critical point $T_c$ are studied by Monte Carlo in two models. Our results confirm predictions of Aharony and Harris based on Renormalization group considerations. For an Ashkin-Teller model with strong but irrelevant bond randomn

Pyeong Jun Park, Wokyung Sung

We study the translocation of a flexible polymer through a pore in a membrane induced by its adsorption on \trans side of the membrane. When temperature $T$ is higher than $T_c$, the adsorption-desorption transition temperature, attractive interaction between polymer and membrane plays little role in affecting polymer conformation, leading to translocation t

Pyeong Jun Park, Wokyung Sung

Translocation of a polymer out of curved surface or membrane is studied via mean first passage time approach. Membrane curvature gives rise to a constraint on polymer conformation, which effectively drives the polymer to the outside of membrane where the available volume of polymer conformational fluctuation is larger. Considering a polymer release out of sp

W. Sung, P. J. Park

We construct a new statistical physical model of polymer translocation through a pore in a membrane treated as the diffusion process across a free energy barrier. We determine the translocation time in terms of chain flexibility yielding an entropic barrier, as well as in terms of the driving mechanisms such as transmembrane chemical potential difference and

S. Wiseman, E. Domany

We simulated site dilute Ising models in $d=3$ dimensions for several lattice sizes $L$. For each $L$ singular thermodynamic quantities $X$ were measured at criticality and their distributions $P(X)$ were determined, for ensembles of several thousand random samples. For $L \to \infty$ the width of $P(X)$ tends to a universal constant, i.e. there is no self a

L G Brunnet, H Chate

Collective oscillations of lattices of locally-coupled chaotic Roessler oscillators are studied with regard to the dynamical scaling of their phase interfaces. Using analogies with the complex Ginzburg-Landau and the Kardar-Parisi-Zhang equations, we argue that phase coherence should be lost in the infinite-size limit. Our numerical results, however, indicat

Eric J. Bakker, David L. Lambert, Hans van Winckel, James K. McCarthy

The H$α$ profile varies with the orbital period. The two strong shell type emission peaks are identified as from one single broad emission feature with an absorption centered around -7.5~\kms. The intensity variations are largely attributed to a differential amount of reddening towards the H$α$ emitting region and the stellar continuum. The radial velocities

G. L. Israel, L. Angelini, S. Campana, P. Giommi

During a systematic search for periodic signals in a sample of ROSAT PSPC (0.1-2.4 keV) light curves, we discovered 12min large amplitude X-ray pulsations in 1WGA J1958.2+3232, an X-ray source which lies close to the galactic plane. The energy spectrum is well fit by a power law with a photon index of 0.8, corresponding to an X-ray flux of about 10E-12 ergs

R. Fusco-Femiano, N. Menci

We compute the evolution of the space-dependent mass distribution of galaxies in clusters due to binary aggregations by solving a space-dependent Smoluchowski equation. We derive the distribution of intergalactic distance for different ranges of mass (and of corresponding magnitude). We compare the results with the observed distributions, and find that the d

Andrea Ferrara

We study the formation of molecular hydrogen in cooling gas behind shocks produced during the blow-away process thought to occur in the first collapsed, luminous (Pop III) objects in the early universe. We find that for a wide range of physical parameters the $H_2$ fraction is $f \approx 6 \times 10^{-3}$. The $H_2$ mass produced in such explosions can excee

C. Charbonnel

Stellar nucleosynthesis is the corner-stone of many astrophysical problems. Its understanding, which can be tested by countless observations, leads to insights into the stellar structure and evolution, and provides crucial clues to the physics of the galaxies and of the universe. Precise answers can be given to the questions ``When, where and how the chemica

C. L. Fryer, S. E. Woosley

The phase-transition induced collapse of a neutron star to a more compact configuration (typically a ``strange'' star) and the subsequent core bounce is often invoked as a model for gamma-ray bursts. We present the results of numerical simulations of this kind of event using realistic neutrino physics and a high density equation of state. The nature

Sergei A. Levshakov, Wilhelm H. Kegel, Fumio Takahara

Deuterium abundance re-measurements by Burles and Tytler (1998; hereafter BT) yielded D/H = (3.3 +/- 0.3) 10^{-5} and the robust upper limit D/H < 3.9 10^{-5} from the z_a = 3.572 system toward Q1937-1009. In this new analysis BT adopted multicomponent microturbulent models together with the possibility to vary freely the local continuum level around each HI

Asantha R. Cooray

We present initial results from a search to detect radio emission at 1.4 GHz from gravitationally lensed arcs towards galaxy clusters. Using the FIRST survey observations of galaxy cluster fields, we have clearly detected 1.4 GHz emission at the location of bright arc towards the galaxy cluster Abell 370. The possibility that this emission is associated with

Diego F. Torres, Gustavo E. Romero, Luis A. Anchordoqui

The extragalactic microlensing scenario for natural wormholes is examined. It is shown that the main features of wormhole lensing events upon the light of distant Active Galactic Nuclei (AGNs) are similar to some types of already observed Gamma Ray Bursts (GRBs). Using recent satellite data on GRBs, an upper limit to the negative mass density -- ${\cal O} (1

Arthur Lue, Mark Trodden

We consider the effect of adding a CP-odd, theta FFdual-term to the electroweak Lagrangian without fermions. This term affects neither the classical nor perturbatively quantum physics, but can be observed through non-perturbative quantum processes. We give an example of such a process by modifying the theory so that it supports Higgs-winding solitons and sho

G. E. Volovik

The gapless fermionic excitations in superfluid 3He-A have a &#34;relativistic&#34; spectrum close to the gap nodes. They are the counterpart of the chiral particles (left-handed and right-handed) in high energy physics above the electroweak transition. We discuss the effective gravity and effective gauge fields, induced by these massless fermions in the low

Andreas Volmer, Sutapa Mukherji, Thomas Nattermann

In anisotropic or layered superconductors thermal fluctuations as well as impurities induce a van der Waals (vdW) attraction between flux lines, as has recently been shown by Blatter and Geshkenbein in the thermal case [Phys. Rev. Lett. 77, 4958 (1996)] and by Mukherji and Nattermann in the disorder dominated case [Phys. Rev. Lett. 79, 139 (1997)]. This attr

Paivi Torma

We consider transitions in quantum networks analogous to those in the two-dimensional Ising model. We show that for a network of active components the transition is between the quantum and the classical behaviour of the network, and the critical amplification coincides with the fundamental quantum cloning limit.

D. Boyanovsky, F. Cooper, H. J. de Vega, P. Sodano

We establish a self-consistent variational framework that allows us to study numerically the non-equilibrium evolution of non-perturbative inhomogeneous field configurations including quantum backreaction effects. After discussing the practical merits and disadvantages of different approaches we provide a closed set of local and renormalizable update equatio

D. V. Antonov

The effects bringing about by the finiteness of the photon mass due to the Debye screening in the monopole gas in three-dimensional compact QED are studied. In this respect, a representation of the partition function of this theory as an integral over monopole densities is derived. Dual formulation of the Wilson loop yields a new theory of confining strings,

Naoto Nagaosa, Shuichi Murakami

We study theoretically the lattice instability in the spin gap systems under magnetic field. With the magnetic field larger than a critical value h_{c1}, the spin gap is collapsed and the magnetization arises. We found that the lattice distortion occurs in the spin-ladder at an incommensurate wavevector corresponding to the magnetization, while it does not o

T. Asaka, J. Hashiba, M. Kawasaki, T. Yanagida

We examine the $X$-ray spectrum from the decay of the dark-matter moduli with mass $\sim {\cal O}(100)$keV, in particular, paying attention to the line spectrum from the moduli trapped in the halo of our galaxy. It is found that with the energy resolution of the current experiments ($\sim 10$%) the line intensity is about twice stronger than that of the cont

Satoshi Nozawa, Naoki Itoh, Yasuharu Kohyama

We calculate the relativistic thermal bremsstrahlung Gaunt factor for the high-temperature plasma which exists in clusters of galaxies. We calculate the Gaunt factor by employing the Bethe-Heitler cross section corrected by the Elwert factor. We also calculate the Gaunt factor by using the Coulomb-distorted wave functions for nonrelativistic electrons follow

J. D. Vergados, T. S. Kosmas

The direct detection rate for supersymmetric cold dark matter (CDM) particles is calculated for a number of suitable nuclear targets. Both the coherent and spin contributions are considered. By considering representative phenomenologically acceptable input in the restricted SUSY parameter space, detectable rates are predicted for some choices of the paramete

M. Dakna, G. Breitenbach, J. Mlynek, T. Opatrny

We directly sample the exponential moments of the canonical phase for various quantum states from the homodyne output. The method enables us to study the phase properties experimentally, without making the detour via reconstructing the density matrix or the Wigner function and calculating the phase statistics from them. In particular, combing the measurement

Masanao Ozawa

The argument is re-examined that the program of deriving the rule of state reduction from the Schroedinger equation holding for the object-apparatus composite system falls into a vicious circle or an infinite regress called the von Neumann chain. It is shown that this argument suffers from a serious physical inconsistency concerning the causality between the

V. Ostrik

For any module $M$ over small quantum group one defines the support variety using construction from the theory of restricted Lie algebras. It is a closed conical subset of nilpotent cone of the corresponding Lie algebra. If module $M$ is a module over the quantum group $U_ξ$ with divided powers then its support variety is invariant under the action of the co

Lancelot I. Kethley

An experiment was conducted with the intent to detect the effect, if any, of the hypothetical centricoris acceleration of freely spinning electrons by the use of an electromagnet with its conductor firmly clamped between its two attracting magnetic plates. It was theorized that the freely spinning electrons were uniformly oriented by the magnetic field, and

Hermann Riecke, Glen D. Granzow

A general localization mechanism for waves in dissipative systems is identified that does not require the bistability of the basic state and the nonlinear plane-wave state. The mechanism explains the two-dimensional localized wave structures (`worms&#39;) that recently have been observed in experiments on electroconvection in nematic liquid crystals where th

A. V. Prokofiev, S. G. Mashnik, A. J. Sierk

An extended version of the Cascade-Exciton Model (CEM) of nuclear reactions is applied to analyze nucleon-induced fission cross sections for Bi-209 and Pb-208 nuclei in the 45-500 MeV energy range. The available data on linear momentum transfer are analyzed as well. The results are compared with analytical approximations resulting from a comparative critical

T. Rauscher

The current status of optical potentials employed in the prediction of thermonuclear reaction rates for astrophysics in the Hauser-Feshbach formalism is discussed. Special emphasis is put on $α$+nucleus potentials. A novel approach for the prediction of $α$+nucleus potentials is proposed. Further experimental efforts are motivated.

V. D. Efros, H. Oberhummer, A. Pushkin, I. J. Thompson

A semi-microscopic model for the low-energy photodisintegration of the 9Be nucleus is constructed, and the experimental data are analyzed with its help. The older radioactive isotope data are supported by this analysis. The theoretical photodisintegration cross section is derived. The astrophysical rates for the reaction alpha + alpha + n -> 9Be + gamma and

David G. Wagner

We define a contravariant functor K from the category of finite graphs and graph morphisms to the category of finitely generated graded abelian groups and homomorphisms. For a graph X, an abelian group B, and a nonnegative integer j, an element of Hom(K^j(X),B) is a coherent family of B-valued flows on the set of all graphs obtained by contracting some (j-1)

David G. Wagner

For a finite multigraph G, the reliability function of G is the probability R_G(q) that if each edge of G is deleted independantly with probability q then the remaining edges of G induce a connected spanning subgraph of G; this is a polynomial function of q. In 1992, Brown and Colbourn conjectured that for any connected multigraph G, if the complex number q

Richard G. E. Pinch

A number $n$ is said to be economical if the prime power factorisation of $n$ can be written with no more digits than $n$ itself. We show that under a plausible hypothesis, related to the twin prime conjecture, there are arbitrarily long sequences of consecutive economial numbers, and exhibit such a sequence of length 9.

Richard F. Bass, Krzysztof Burdzy

We study an ordinary differential equation controlled by a stochastic process. We present results on existence and uniqueness of solutions, on associated local times (Trotter and Ray-Knight theorems), and on time and direction of bifurcation. A relationship with Lipschitz approximations to Brownian paths is also discussed.

Yujiro Kawamata

We shall investigate index 1 covers of 2-dimensional log terminal singularities. The main result is that the index 1 cover is canonical if the characteristic of the base field is different from 2 or 3. We also give some counterexamples in the case of characteristic 2 or 3. By using this result, we correct an error in a previous paper.

M. Seeger, M. Thies

We reexamine the solvable model problem of two static, fundamental quarks interacting with a SU(2) Yang-Mills field on a spatial circle, introduced by Engelhardt and Schreiber. If the quarks are at the same point, the model exhibits a quantum mechanical supersymmetry. At finite separation, the supersymmetry is explicitly broken in a way which naturally expla

Nils R. Scheithauer

Certain vertex algebras and Lie algebras arising in superstring theory are investigated. We show that the Fock space of a compactified Neveu-Schwarz superstring, i.e. a Neveu-Schwarz superstring moving on a torus, carries the structure of a vertex superalgebra with a Neveu-Schwarz element. This implies that the physical states of such a string form a Lie alg

Yu. A. Sitenko, D. G. Rakityansky

Effects due to fermion-vacuum polarization by an external static magnetic field are considered in a two-dimensional noncompact curved space with a nontrivial topology. An expression for the vacuun angular momentum is obtained. Like the vacuum fermion number, it proves to be dependent on the global characteristics of the field and space.

Yu. A. Sitenko, D. G. Rakityansky

A singular configuration of an external static vector field in the form of a magnetic string polarizes the vacuum of a second-quantized theory on the plane orthogonal to the string axis. The most general boundary conditions at the punctured singular point that are compatible with the self-adjointness of two-dimensional Dirac Hamiltonian are considered. The d

Kazuto Oshima

We study supersymmetric quantum mechanics on RP_{n},SO(n),G_{2} and U(2) to examine Witten&#39;s Morse theory concretely. We confirm the simple instanton picture of the de Rham cohomology that has been given in a previous paper. We use a reflection symmetry of each theory to select the true vacuums. The number of selected vacuums agrees with the de Rham coho

Miao Li

D0-brane theory on a torus with a nonvanishing B field is embedded into a string theory in the weak coupling limit. It is shown that the usual supersymmetric Yang-Mills theory on a noncommutative torus can not be the whole story. The Born-Infeld action survives the noncommutative torus limit.

Thomas C. Kraan, Pierre van Baal

We determine all SU(2) caloron solutions with topological charge one and arbitrary Polyakov loop at spatial infinity (with trace 2.cos(2.pi.omega)), using the Nahm duality transformation and ADHM. By explicit computations we show that the moduli space is given by a product of the base manifold R^3 X S^1 and a Taub-NUT space with mass M=1/sqrt{8.omega(1-2.ome

H. D. Dahmen, A. A. Maslikov, I. A. Naumov, T. Stroh

In the framework of the four dimensional heterotic superstring with free world-sheet fermions we study the GUSTs which contain non-abelian horizontal symmetry. To solve the problem of breaking the G_GUT gauge symmetry of the level one current algebra we extend the gauge symmetry to G x G. Using the autoduality of the fermionic charge lattice we study the pos

Silas R. Beane

An empirically successful mass formula derived long ago from hadronic string models is not explained by symmetries of the QCD lagrangian. Consider that M(rho)^2-M(pi)^2 = M(K*)^2-M(K)^2 to a few percent accuracy. We derive this and other equal spacing relations using chiral symmetry and a novel Z_2 symmetry. We offer an interpretation of this Z_2 symmetry as

K. A. Milton, I. L. Solovtsov, V. I. Yasnov

We apply analytic perturbation theory in next-to-next-to-leading order to inclusive semileptonic $τ$-decay and study the renormalization scheme dependence. We argue that the renormalization scheme ambiguity is considerably reduced in the analytic perturbation theory framework and we obtain a rather stable theoretical prediction.

T. Kobayashi, J. Kubo, M. Mondragon, G. Zoupanos

A new solution to the requirement of two-loop finiteness of the soft supersymmetry breaking terms (SSB) parameters is found in Finite-Gauge-Yukawa unified theories. The new solution has the form of a sum rule for the relevant scalar masses, relaxing the universality required by the previously known solution, which leads to models with unpleasant phenomenolog

Stephen Parke

Top quark pair production is presented at a polarized Muon Collider above the threshold region. The off-diagonal spin basis is the natural basis for this discussion as the top quark pairs are produced in an essentially unique spin configuration for 100% polarization. Modest polarization, say 30%, can lead to 90% of all top quark pair events being in one spin

L. Motyka, J. Kwiecinski

The reactions gamma-gamma to eta_c eta_c and gamma gamma to eta_c + X are discussed within the three gluon exchange model. We give predictions for the differential cross-sections and discuss feasibility of measuring these processes at LEP2 and TESLA. The total cross-sections were estimated to be approximately equal to 40 fb and 120 fb for gamma-gamma to eta_

K. Funakubo, A. Kakuto, S. Otsuki, F. Toyoda

By studying the effective potential of the MSSM at finite temperature, we find that CP can be spontaneously broken in the intermediate region between the symmetric and broken phases separated by the bubble wall created at the phase transition. This type of CP violation is necessary to have a bubble wall profile connecting CP conserving vacua, while violating

Javier Ferrandis

We consider the charged scalar boson phenomenology in the bilinear R-parity breaking model which induces a mixing between staus and the charged Higgs boson. The charged Higgs boson mass can be lower than expected in the MSSM, even before including radiative corrections. The R-parity violating decay rates can be comparable or even bigger than the R-parity con

M. Baker, N. Brambilla, H. G. Dosch, A. Vairo

We establish a relation between the two-point field strength correlator in QCD and the dual field propagator of an effective dual Abelian Higgs model describing the infrared behaviour of QCD. We find an analytic approximation to the dual field propagator without sources and in presence of quark sources. In the latter situation we also obtain an expression fo

Muneyuki Ishida, Shin Ishida, Taku Ishida

A recent criticism raised by M.R.Pennington on our pipi-production amplitudes seems to be due to his misunderstanding on our description, and is not right. Essential point of the relation between our scattering and production amplitudes is, in connection to the unitarity and the final state interaction theorem, briefly explained.

J. C. Collins

The original version of this paper commented on a paper by Jaffe, Jin, and Tang (hep-ph/9710561). That paper has been revised, and my original comment no longer applies to the revised version. The original version of my comment (hep-ph/9801217v1) provides a simple argument that two-particle correlations in parity-invariant fragmentation cannot provide a meas

Thibault Damour, Gilles Esposito-Farese

We study the deflection of light (and the redshift, or integrated time delay) caused by the time-dependent gravitational field generated by a localized material source lying close to the line of sight. Our calculation explicitly takes into account the full, near-zone, plus intermediate-zone, plus wave-zone, retarded gravitational field. Contrary to several r

J. A. Lobo, J. A. Ortega

Internal friction effects are responsible for line widening of the resonance frequencies in spherical gravitational wave detectors, and result in exponentially damped oscillations of its eigenmodes with a decay time which is proportional to the quality factor of the mode and to its inverse frequency. We study the solutions to the equations of motion for a vi

Jorge Pullin

Contents: *News: Topical group news, by Jim Isenberg April 1997 Joint APS/AAPT Meeting, GTG program, by Abhay Ashtekar Formation of the Gravitational-Wave International Committee, by Sam Finn The 1997 Xanthopoulos award, by Abhay Asthekar We hear that..., by Jorge Pullin *Research Briefs: LIGO project update, by David Shoemaker The search for frame-dragging

E. H. Hwang, S. Das Sarma

We investigate the dynamical self-energy corrections of the electron-hole plasma due to electron-electron and electron-phonon interactions at the band edges of a quasi-one dimensional (1D) photoexcited electron-hole plasma. The leading-order $GW$ dynamical screening approximation is used in the calculation by treating electron-electron Coulomb interaction an

Daniel C. Hong, Kevin McGouldrick

We present a computational random walk method of measuring the isothermal pressure of the lattice gas with and without the excluded volume interaction. The method is based on the discretization of the exact thermodynamic relation for the pressure. The simulation results are in excellent agreement with the theoretical predictions.

Douglas A. Kurtze, Daniel C. Hong

We study the effect of dissipation on the density profile of a one dimensional gas that is subject to gravity. The gas is in thermal equilibrium at temperature T with a heat reservoir at the bottom wall. Perturbative analysis of the Boltzmann equation reveals that the correction due to dissipation resulting from inelastic collisions is positive for $0<z<z_c$

Marco Picco

We present results of a numerical simulation of the $q$-state random bond Potts model in two dimensions and for large $q$. In particular, care is taken to study the crossover from the pure model to the random model, as well as the crossover from the percolation to the random model. We show how to determine precisely the random fixed point and measure critica

S. Das Sarma, E. H. Hwang

Using a conventional BCS -- Fermi liquid model we calculate the c-axis optical reflectivity of the layered high temperature cuprate superconductors by obtaining the finite temperature dynamical dielectric function in a microscopic self-consistent gauge invariant formalism. We get good semi-quantitative agreement with all the existing experimental data by usi

M. Ain, J. E. Lorenzo, L. P. Regnault, G. Dhalenne

We have studied magnetic excitations in the dimerized spin-Peierls phase of CuGeO3, by high resolution inelastic neutron scattering. We measured the well-defined spin triplet dispersive mode which is gapped throughout the whole Brillouin zone. We also observed that this mode is separated by an unexpected second gap of order 2 meV from a continuum of magnetic

Barbara Drossel, Karin Dahmen

We report studies of the behaviour of a single driven domain wall in the 2-dimensional non-equilibrium zero temperature random-field Ising model, closely above the depinning threshold. It is found that even for very weak disorder, the domain wall moves through the system in percolative fashion. At depinning, the fraction of spins that are flipped by the proc

O. Stockert, H. v. Löhneysen, A. Rosch, N. Pyka

The heavy-fermion system CeCu_{6-x}Au_x exhibits a quantum critical point at x_c = 0.1 separating nonmagnetic and magnetically ordered ground states. The pronounced non-Fermi-liquid behavior at x_c calls for a search for the relevant quantum critical fluctuations. Systematic measurements of the inelastic neutron scattering cross section S(q,omega) for x = 0.

Shirish M. Chitanvis

Using methods of functional integration, and performing simple Gaussian integrals, I show that an interacting system of electrons can be bosonized in arbitrary dimensions, in terms of the electrostatic potential which mediates the interaction between them. Working with the bosonic field, the sytem is shown to exhibit localized structures reminiscent of strip

J. Bezecourt

Number counts and redshift distribution of gravitational arcs are computed in the field of massive clusters of galaxies to probe the universe at high redshift. Using an accurate modelling for the cluster mass distribution and a model for the spectrophotometric evolution of galaxies, the redshift distribution of gravitational arclets is computed in the field

Joel N. Bregman, Brian A. Snider, Laura Grego, Caroline V. Cox

Studies of cold material through IRAS 60um and 100um observations indicated that half of ordinary E and E/S0 galaxies were detected above the 3 sigma level, indicating that cold gas is common, although no correlation was found between the optical and far- infrared fluxes. Most detections were near the instrumental threshold, and given an improved understandi