February 1997 arXiv papers — page 14

Avinash Khare, M. Sivakumar

We consider the supersymmetric Calogero-Sutherland type N-particle problems in one dimension and show that the corresponding fermionic part can be identified with the generalized X-Y models in the presence of an inhomogeneous magnetic field. In particular we show that the generalized Haldane-Shastry models (with magnetic field) are themselves the fermionic p

J. Twamley

We quantise the centre of mass motion of a neutral Cs atom in the presence of a classical Gaussian-Laguerre$_{10}$ light field in the large detuning limit. This light field possesses orbital angular momentum which is transferred to the atom via spontaneous emissions. We use quantum trajectory and analytic methods to solve the master equation for the 2d centr

Claude Cibils

We show that finite dimensional half-quantum groups at roots of unity corresponding to simple Lie algebras having symmetric Cartan matrix are of wild representation type, except for sl_2. Moreover, the underlying associative algebra is isomorphic to an admissible quotient of the path algebra of the Cayley graph of an abelian group. A quantum type Fourier tra

Denis V. Juriev

The relations between the infinite dimensional geometry of $q_R$-conformal symmetries at $q_R\to\infty$, Berezin quantization of the Lobachevskii plane and Karasev-Maslov asymptotic quantization are explicated. Some aspects of the ``approximate'' representation theory are discussed.

M. Nio, T. Kinoshita

This is the second of a series of papers on the radiative corrections of order $α^2 (Zα)$, $α(Zα)^2$, and various logarithmic terms of order $α^4$, to the hyperfine structure of the muonium ground state. This paper deals with the $α(Zα)^2$ correction. Based on the NRQED bound state theory, we isolated the term of order $α(Zα)^2$ exactly. Our result $+16.904

S. Khoroshkin, D. Lebedev, S. Pakuliak

The scaling limit $A_{\hbar,η}(\hat{sl_2})$ of the elliptic algebra $A_{q,p}(\hat{sl_2})$ is investigated. The limiting algebra is defined in terms of a continuous family of generators being Fourier harmonics of Gauss coordinates of the $L$-operator. Ding-Frenkel isomorphism between $L$-operator's and current descriptions of the algebra $A_{\hbar,η}(\hat

Ken-ichi Matsuba, Kazuhiro Nozaki

It is shown that the renormalization group method does not necessarily eliminate all secular terms in perturbation series to partial differential equations and a functional subspace of renormalizable secular solutions corresponds to a choice of scales of independent variables in the reductive perturbation method.

C. Oh, R. A. Arndt, I. I. Strakovsky, R. L. Workman

Results are presented for a combined analysis of the reactions $pp\to pp$, $πd\to πd$ and $πd\to pp$ over the $\sqrt{s}$ interval from pion threshold to approximately 2.4 GeV. These results for $πd\to pp$ and $πd$ elastic scattering are superior to our previous analyses of these reactions. In particular, the overall phase in $πd\to pp$ has now been determine

A. P. Isaev, P. P. Kulish

Reflection equation for the scattering of lines moving in half-plane is obtained. The corresponding geometric picture is related with configurations of half-planes touching the boundary plane in 2+1 dimensions. This equation can be obtained as an additional to the tetrahedron equation consistency condition for a modified Zamolodchikov algebra.

Jürgen Schulze, Nicholas P. Warner

We introduce some techniques for making a more global analysis of the existence of geodesics on a Seiberg-Witten Riemann surface with metric $ds^2 = |λ_{SW}|^2$. Because the existence of such geodesics implies the existence of BPS states in N=2 supersymmetric Yang-Mills theory, one can use these methods to study the BPS spectrum in various phases of the Yang

Aharon Levy

It is shown that by assuming Gribov factorization to hold at low $x$ one obtains a simple relation between the structure function of the proton and that of the photon. By interpreting an observed structure in deep inelastic scattering (DIS) of leptons on protons as belonging to the proton, one can relate it to the structure of the exchanged photon, and visa

I. N. Mishustin, O. Scavenius

We investigate dynamics of the chiral transition in expanding quark-antiquark plasma produced in an ultra-relativistic heavy ion collision. The chiral symmetry break-down and dynamical generation of the constituent quark mass are studied within the linear sigma model and Nambu-Jona-Lasinio model. Time dependence of the quark and antiquark densities is obtain

Robert H. Brandenberger

Modern cosmology provides a connection between the physics of particles and fields and observational cosmology. Making use of this link, a wealth of new observational data can be utilized to explore and constrain theories of fundamental physics. Inflationary Universe models and topological defect theories are the most popular current paradigms for explaining

Junji Hisano, Shingo Kiyoura, Hitoshi Murayama

It has been known that $R_b$ can be enhanced in the two Higgs doublet model if $\tan β$ is large. We point out that a similar enhancement in $Γ(Z \to τ^+ τ^-)$ is large enough to place a constraint on such a possibility. We obtain a 95% CL upper bound $ΔR_b/R_{b} < 0.73%$ in this model for the $\overline{MS}$ mass $m_{b} (m_{Z}) = 3.0$ GeV. The 1996 world av

Marian Boguna, Alvaro Corral

We present a continuous time random walk model for the scale-invariant transport found in a self-organized critical rice pile [Christensen et al., Phys. Rev. Lett. 77, 107 (1996)]. From our analytical results it is shown that the dynamics of the experiment can be explained in terms of Lévy flights for the grains and a long-tailed distribution of trapping tim

Stefan Scheidl, Valerii Vinokur

The dynamics of dislocations in a two-dimensional vortex lattice is studied in the presence of a pinning potential and a transport current. In a vortex lattice drifting with velocity $v$ a glide velocity $V_d$ of the dislocation with respect to the vortex lattice is found to decay like $V_d \sim v^{-4}$ for large drive. From this result the velocity for the

A. L. Chudnovskiy, R. Oppermann, B. Rosenow, D. R. Yakovlev

A theory accounting for the specific features of magnetic polarons (MP) in the presence of spin glass order is presented. We derive and solve selfconsistent equations for i) the polaron magnetisation, ii) the thermodynamically averaged carrier--spin, and iii) for the spin glass order parameter. The temperature dependence of these quantities is analysed in de

Q. Daniel Wang, Andrew Connolly, Robert Brunner

Based on a deep ROSAT/PSPC observation, we reveal an elongated complex of extended X-ray-emitting objects in and around the galaxy cluster A2125. Multicolor optical imaging of galaxies in the field suggests that this complex represents a hierarchical superstructure spanning about 11 Mpc at redshift z = 0.247. The multi-peak X-ray morphology of A2125 suggests

Hsiang-Kuang Chang, Cheng Ho

We report results of RXTE observations of PSR B1951+32 using the PCA instrument for 19k seconds during 1996 March 24th. We applied the contemporaneous radio ephemeris and various statistical tests to search for evidence of pulsation. These analyses yield intriguing yet inconclusive evidence for the presence of the pulsation in the time series: confidence lev

Frank Antonsen, Karsten Bormann

We calculate the effective potentials for scalar, Dirac and Yang-Mills fields in curved backgrounds using a new method for the determination of the heat kernel involving a re-summation of the Schwinger-DeWitt series. Self-interactions are treated both to one loop order as usual and slightly beyond one-loop order by means of a mean-field approximation. The ne

L. Frankfurt, W. Koepf, M. Strikman

Hard diffractive photo- and electroproduction of heavy vector mesons ($J/ψ$ and $Υ$) is evaluated within the leading $α_s\ln{Q^2 \overΛ_{QCD}^2}$ approximation of QCD. In difference from our earlier work on that subject, also the production of transversely polarized vector mesons is calculated. Special emphasis is placed on the role of the vector meson&#39;s

Tetsu Kitayama, Yasushi Suto

We find that the observed log N - log S relation of X-ray clusters can be reproduced remarkably well with a certain range of values for the fluctuation amplitude $σ_8$ and the cosmological density parameter $Ω_0$ in cold dark matter (CDM) universes. The $1σ$ confidence limits on $σ_8$ in the CDM models with $n=1$ and $h = 0.7$ are expressed as $(0.54 \pm 0.0

Z. Papp

Based on a three-potential formalism we propose mathematically well-behaved Faddeev-type integral equations for the atomic three-body problem and descibe their solutions in Coulomb-Sturmian space representation. Although the system contains only long-range Coulomb interactions these equations allow us to reach solution by approximating only some auxiliary sh

P. S. Howe, E. Sezgin, P. C. West

The component form of the equations of motion for the 5-brane in eleven-dimensions is derived from the superspace equations. These equations are fully covariant in six-dimensions. It is shown that double-dimensional reduction of the bosonic equations gives the equations of motion for a 4-brane in ten dimensions governed by the Born-Infeld action.

István Szapudi, Alexander S. Szalay

This work presents a set of new statistics, the cumulant correlators, aimed at high precision analysis of the galaxy distribution. They form a symmetric matrix, $Q_{NM}$, related to moment correlators the same way as cumulants are related to the moments of the distribution. They encode more information than the usual cumulants, $S_N$&#39;s, and their extract

M. B. Plenio, P. L. Knight

Dissipation, the irreversible loss of energy and coherence, from a microsystem, is the result of coupling to a much larger macrosystem (or reservoir) which is so large that one has no chance of keeping track of all of its degrees of freedom. The microsystem evolution is then described by tracing over the reservoir states, resulting in an irreversible decay a

Hagen Kleinert, Sergei V. Shabanov

We show that an unambiguous and correct quantization of the second-class constrained system of a free particle on a sphere in $D$ dimensions is possible only by converting the constraints to abelian gauge constraints, which are of first class in Dirac&#39;s classification scheme. The energy spectrum is equal to that of a pure Laplace-Beltrami operator with n

I. M. Isaacs, Greg Knutson

Let N be a normal subgroup of a finite group G and consider the set cd(G|N) of degrees of irreducible characters of G whose kernels do not contain N. A number of theorems are proved relating the set cd(G|N) to the structure of N. For example, if N is solvable, its derived length is bounded above by a function of |cd(G|N)|. Also, if |cd(G|N)| is at most 2, th

I. M. Isaacs, David Petrie Moulton

The main result of this paper is that if E is a field extension of finite odd degree over a real field Q, and if E is a repeated radical extension of Q, then every intermediate field is also a repeated radical extension of Q. This paper also contains a number of other results about repeated radical extensions.

R. Holman, S. Prem Kumar

We consider theories with a spontaneously broken gauged R-symmetry, which can only occur in supergravity models. These give rise to cosmic R-strings upon which gravitino zero modes can exist. We construct solutions to the Rarita-Schwinger spin-3/2 equation describing the gravitino in the field of these cosmic strings and show that under some conditions these

K. Behrndt, W. A. Sabra

We employ the principle of minimal central charge and study the entropy of N=2 black holes corresponding to the most general quadratic prepotential. We also give a static black hole solution for these models in which the scalar moduli are non constants. Finally, we speculate on the microscopic origin for our solution.

S. Lupia

The perturbative QCD approach, based on Modified Leading Log Approximation and Local Parton Hadron Duality, is shown to describe inclusive features of multiparticle production in the soft region. Further predictions of this approach are discussed.

Sourendu Gupta, S. N. Nayak

We study the effect of finite temperatures and Fermion density on the effective pseudo-scalar-photon vertex induced by the triangle diagram. The manifestly covariant calculations show that when the pseudo-scalar mass is much less than the temperature, then there is a large enhancement of the decay rate. Alternatively, when the temperature is much higher than

K. Abe

The lifetimes of B+ and B0 mesons have been measured using a sample of 150,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis reconstructs the decay length and charge of the B meson using a novel topological vertexing technique. This method results in a high statistics sample of 6033 (3665) charged (neutral)

K. Abe

The lifetimes of B+ and B0 mesons are measured using a sample of 150,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. This new method results i

L. R. Abramo, R. H. Brandenberger, V. M. Mukhanov

The back reaction of gravitational perturbations in a homogeneous background is determined by an effective energy-momentum tensor quadratic in the perturbations. We show that this nonlinear feedback effect is important in the case of long wavelength scalar perturbations in inflationary universe models. We also show how to solve an old problem concerning the

R. Estrada, J. M. Gracia-Bondia, J. C. Varilly

Modulo the moment asymptotic expansion, the Cesaro and parametric behaviours of distributions at infinity are equivalent. On the strength of this result, we construct the asymptotic analysis for spectral densities, arising from elliptic pseudodifferential operators. We show how Cesaro developments lead to efficient calculations of the expansion coefficients

I. L. Aleiner, Ned S. Wingreen, Yigal Meir

The ``Which Path?&#39;&#39; interferometer consists of an Aharonov-Bohm ring with a quantum dot (QD) built in one of its arms, and an additional quantum point contact (QPC) located close to the QD. The transmission coefficient of the QPC depends on the charge state of the QD. Hence the point contact causes controllable dephasing of transport through the QD,

R. O. Grigoriev, M. C. Cross

A particularly simple model belonging to a wide class of coupled maps which obey a local conservation law is studied. The phase structure of the system and the types of the phase transitions are determined. It is argued that the structure of the phase diagram is robust with respect to mild violations of the conservation law. Critical exponents possibly deter

Howard E. Bond

Stars evolving off the asymptotic giant branch and passing through spectral types F and A are excellent candidates for a new extragalactic candle. These post-AGB (PAGB) stars are the brightest members of Population II systems. They should have a narrow luminosity function, bounded from above by the shorter transition times of more massive and more luminous r