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Sep 21, 2009
09/09
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*Credit:* C.R. O'Dell/Rice University; NASA [ http://www.nasa.gov/ ]
image
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*Description*: A Hubble Space Telescope view of a very young star (between 300,000 and a million years of age) surrounded by material left over from the star's formation. The cool, reddish star is about one fifth the mass of our Sun. The dark disk, seen in silhouette against the background of the Orion Nebula, is possibly a protoplanetary disk from which planets will form. The disk contains at least seven times the material as our Earth. The disk is 56 billion miles across (90 billion...
Topics: NGC 1976, M42, Orion Nebula, What -- Hubble Space Telescope (HST), What -- Sun, What -- Orion, What...
Source: http://hubblesite.org/newscenter/archive/releases/1994/24/image/c/
9,509
9.5K
Sep 21, 2009
09/09
by
*Credit:* C.R. O'Dell/Rice University; NASA [ http://www.nasa.gov/ ]
image
eye 9,509
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*Description*: A Hubble Space Telescope view of a small portion of the Orion Nebula reveals five young stars. Four of the stars are surrounded by gas and dust trapped as the stars formed, but were left in orbit about the star. These are possibly protoplanetary disks, or "proplyds," that might evolve on to agglomerate planets. The proplyds which are closest to the hottest stars of the parent star cluster are seen as bright objects, while the object farthest from the hottest stars is...
Topics: NGC 1976, M42, Orion Nebula, What -- Hubble Space Telescope (HST), What -- Orion, What --...
Source: http://hubblesite.org/newscenter/archive/releases/1994/24/image/b/
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Sep 21, 2009
09/09
by
*Credit:* C.R. O'Dell/Rice University; NASA [ http://www.nasa.gov/ ]
movies
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*Description*: A NASA Hubble Space Telescope image of a region of the Great Nebula in Orion. This is one of the nearest regions of very recent star formation (300,000 years ago). The nebula is a giant gas cloud illuminated by the brightest of the young hot stars at the top of the picture. Many of the fainter young stars are surrounded by disks of dust and gas that are slightly more than twice the diameter of the Solar System. The great plume of gas in the lower left in this picture is the...
Topics: NGC 1976, M42, Orion Nebula, What -- Hubble Space Telescope (HST), What -- Orion, What -- Earth,...
Source: http://hubblesite.org/newscenter/archive/releases/1994/24/image/a/
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Apr 16, 2020
04/20
by
.....
texts
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16
Dec 23, 2016
12/16
by
2600
audio
eye 16
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New traffic cameras in New York City, a call for Metrocard info, the OJ case and cellular phones. Bernie S. is the guest., New traffic cameras in New York City, a call for Metrocard info, the OJ case and cellular phones. Bernie S. is the guest.
Topics: 2600, Off The Hook, WBAI, 2600
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17
Dec 23, 2016
12/16
by
2600
audio
eye 17
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Calling North Korea, theories on Metrocard, tracing the history of a Metrocard over the phone, a field trip to other IRC channels, Emmanuel appears on "Nightline" again., Calling North Korea, theories on Metrocard, tracing the history of a Metrocard over the phone, a field trip to other IRC channels, Emmanuel appears on "Nightline" again.
Topics: 2600, Off The Hook, WBAI, 2600
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12
Dec 23, 2016
12/16
by
2600
audio
eye 12
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500 area code update, getting info on a fictitious number, a demonstration of People Mover, Ed from Long Island has a misadventure with Metrocard, Brock Meeks on the latest Clipper controversy and his legal defense, details on the Matt Blaze compromising of the Clipper system. The beginning of this show is missing., 500 area code update, getting info on a fictitious number, a demonstration of People Mover, Ed from Long Island has a misadventure with Metrocard, Brock Meeks on the latest Clipper...
Topics: 2600, Off The Hook, WBAI, 2600
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18
Dec 23, 2016
12/16
by
2600
audio
eye 18
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AT&T introduces 1-800-CALL-ATT to replace 1-800-OPERATOR, a man becomes a millionaire for a short while due to a bank error, some old phone company commercials, playing with Call Mover live on the air, 1-800-I-FEEL-OK., AT&T introduces 1-800-CALL-ATT to replace 1-800-OPERATOR, a man becomes a millionaire for a short while due to a bank error, some old phone company commercials, playing with Call Mover live on the air, 1-800-I-FEEL-OK.
Topics: 2600, Off The Hook, WBAI, 2600
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109
Jan 3, 2019
01/19
by
2MBS
audio
eye 109
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Sydney's Funkin' Lessons from June 1994. Pick Up The Pieces by Barsha Down South by Down South Homicide by Godfather Don Gusto by The Troubleneck Brothers Fat Rat by Grand Puba Respect by Mr. X & Mr. Z Just Having Fun by Doug E. Fresh With Chill Will & Barry Bee Situation Critical by Arabian Prince Reminiscing by Home Team Doggy Dogg World (Partial) by Snoop Doggy Dogg Featuring Dat Nigga Daz, Kurupt Tha Kingpin & Nancy Fletcher Just Kickin' It by MC Breed & DFC The Big...
Topics: hip-hop, radio, sydney, australia
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210
Feb 23, 2018
02/18
by
A Flock of Seagulls; Bow Wow Wow; Frank; Moon Zappa; Gang of Four; Great Buildings; Haircut One Hundred; Japan; Kim Wilde; Marshall Crenshaw; Pete Shelley; Soft Cell; The Go‐Go’s; The Jam; The Waitresses; Tommy Tutone; Toni Basil
audio
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Tracklist: 1. I Want Candy - Bow Wow Wow 2. I Know What Boys Like - The Waitresses 3. Kids in America - Kim Wilde 4. Love Plus One - Haircut One Hundred 5. Someday, Someway - Marshall Crenshaw 6. Hold on to Something - Great Buildings 7. Town Called Malice - The Jam 8. 867‒5309/Jenny - Tommy Tutone 9. Vacation - The Go‐Go’s 10. Valley Girl - Frank; Moon Zappa 11. I Ran (So Far Away) - A Flock of Seagulls 12. Sex Dwarf - Soft Cell 13. I Love a Man in a Uniform - Gang of Four 14. The Art of...
Topic: Compilation
Source: CD
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62
Sep 23, 2013
09/13
by
A. A. Aligia; L. Arrachea
texts
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We obtain the exact solution of a general Hubbard chain with kinetic energy $t$, bond-charge interaction $X$ and on-site interaction $U$ with the only restriction $t = X$. At zero temperature and half filling, the model exhibits a Mott transition at $U = 4t$. In the metallic phase and near half filling, superconducting states are part of the degenerate ground state and are favored for small $U$ if the system is slightly perturbed.
Source: http://arxiv.org/abs/cond-mat/9406122v1
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51
Sep 23, 2013
09/13
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A. A. Kehagias
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eye 51
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We present here all the real algebras $\cal{A}$ with dim$\cal{A}\leq $5 and all 6-dimensional nilpotent ones with symmetric, invariant and non-degenerate metrics for which a WZW model can be constructed. In three and four dimensions there are no other algebras than the well known $SU(2)$, $SU(1,1)$, $E_2^c$ and $H_4$. There exist only one five-dimensional and one six-dimensional nilpotent algebra with invariant non-degenerate metric and central charge $c=5, \,6$, respectively. We examine in...
Source: http://arxiv.org/abs/hep-th/9406136v1
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46
Sep 23, 2013
09/13
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A. A. Kirillov
texts
eye 46
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A new approach is suggested which allows to describe phenomenologically arbitrary topologies of the Universe. It consists in a generalizaton of third quantization. This quantization is carried out for the case of asymptotic closeness to a cosmological singularity. It is also pointed out that suggested approach leads to a modification of the ordinary quantum field theory. In order to show this modification we consider the example of a free massless scalar field.
Source: http://arxiv.org/abs/gr-qc/9406051v1
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Sep 23, 2013
09/13
by
A. Arhrib; M. Capdequi Peyranere; G. Moultaka
texts
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Top and bottom one loop corrections to $e^+e^-\rightarrow H^+ H^-$ are considered at NLC energies and found to be significantly large and negative over the full range of $tan \, \beta$. Moreover, loop effects of moderately heavy squarks and sleptons in the minimal supersymmetric extension of the standard model, tend to cancel partly or fully these large corrections, thus providing a useful indirect information about the supersymmetric sector. The overall effect can still range between $-25 \%$...
Source: http://arxiv.org/abs/hep-ph/9406357v1
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Sep 19, 2013
09/13
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A. Ashtekar; Ranjeet S. Tate
texts
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An extension of the Dirac procedure for the quantization of constrained systems is necessary to address certain issues that are left open in Dirac's original proposal. These issues play an important role especially in the context of non-linear, diffeomorphism invariant theories such as general relativity. Recently, an extension of the required type was proposed by one of us using algebraic quantization methods. In this paper, the key conceptual and technical aspects of the algebraic program are...
Source: http://arxiv.org/abs/gr-qc/9405073v2
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116
Sep 21, 2013
09/13
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A. B. Finnila; M. A. Gomez; C. Sebenik; C. Stenson; J. D. Doll
texts
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Quantum annealing is a new method for finding extrema of multidimensional functions. Based on an extension of classical, simulated annealing, this approach appears robust with respect to avoiding local minima. Further, unlike some of its predecessors, it does not require an approximation to a wavefunction. In this paper, we apply the technique to the problem of finding the lowest energy configurations of Lennard-Jones clusters of up to 19 particles (roughly 10$^5$ local minima). This early...
Source: http://arxiv.org/abs/chem-ph/9404003v2
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51
Sep 19, 2013
09/13
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A. B. Lahanas; V. C. Spanos
texts
eye 51
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We systematically analyze the anomalous dipole $\Delta k_{\gamma}$ and quadrupole $\Delta Q_{\gamma}$ moments of the W gauge bosons in the context of the minimal supersymmetric standard model as functions of the soft SUSY breaking parameters $A_0,m_0,M_{1/2}$ and the top quark mass. The severe constraints imposed by the radiative breaking mechanism of the electroweak symmetry\,$ SU(2)\times U(1)$\, are duly taken into account. The supesymmetric values of $\Delta k_{\gamma}$ and $\Delta...
Source: http://arxiv.org/abs/hep-ph/9405298v2
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Sep 23, 2013
09/13
by
A. Balinsky
texts
eye 56
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New algebraic structure on the orbits of dressing transformations of the quasitriangular Poisson Lie groups is provided. This give the topological interpretation of the link invariants associated with the Weinstein--Xu classical solutions of the quantum Yang-Baxter equation. Some applications to the three-dimensional topological quantum field theories are discussed.
Source: http://arxiv.org/abs/hep-th/9406113v1
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Sep 23, 2013
09/13
by
A. Barducci; R. Casalbuoni; R. Gatto; M. Modugno; G. Pettini
texts
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We study the thermodynamics of massive Gross-Neveu models with explicitly broken discrete or continuous chiral symmetries for finite temperature and fermion densities. The large $N$ limit is discussed bearing attention to the no-go theorems for symmetry breaking in two dimensions which apply to the massless cases. The main purpose of the study is to serve as analytical orientation for the more complex problem of chiral transition in $4-$dimensional QCD with quarks. For any non-vanishing fermion...
Source: http://arxiv.org/abs/hep-th/9406117v1
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Sep 23, 2013
09/13
by
A. Bialas; R. Peschanski
texts
eye 44
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It is pointed out that accurate measurements of short-range two-particle correlations in like-charge $ K\pi $ and in $ \pi^ 0\pi^ 0$ channels should be very helpful in determining the origin of the \lq\lq intermittency\rq\rq\ phenomenon observed recently for the like-charge pion pairs.
Source: http://arxiv.org/abs/hep-ph/9406360v1
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Sep 23, 2013
09/13
by
A. Borgida; P. F. Patel-Schneider
texts
eye 42
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This paper analyzes the correctness of the subsumption algorithm used in CLASSIC, a description logic-based knowledge representation system that is being used in practical applications. In order to deal efficiently with individuals in CLASSIC descriptions, the developers have had to use an algorithm that is incomplete with respect to the standard, model-theoretic semantics for description logics. We provide a variant semantics for descriptions with respect to which the current implementation is...
Source: http://arxiv.org/abs/cs/9406101v1
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48
Sep 21, 2013
09/13
by
A. Brandenburg; S. J. Brodsky; V. V. Khoze; D. Müller
texts
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We calculate the angular distribution of the lepton produced in the Drell-Yan reaction taking into account pion bound state effects. We work in the kinematic region where one of the pion constituents goes far off-shell, which allows us to treat the bound state problem perturbatively. We show that the angular distribution is very sensitive to the shape of the pion distribution amplitude. The model we discuss fits the data if we choose a two-humped pion distribution amplitude suggested by QCD sum...
Source: http://arxiv.org/abs/hep-ph/9403361v2
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Sep 23, 2013
09/13
by
A. C. C Coolen; D. Sherrington
texts
eye 67
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We present a theory to describe the dynamics of the Sherrington- Kirkpatrick spin-glass with (sequential) Glauber dynamics in terms of deterministic flow equations for macroscopic parameters. Two transparent assumptions allow us to close the macroscopic laws. Replica theory enters as a tool in the calculation of the time- dependent local field distribution. The theory produces in a natural way dynamical generalisations of the AT- and zero-entropy lines and of Parisi's order parameter function...
Source: http://arxiv.org/abs/cond-mat/9406104v1
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51
Sep 23, 2013
09/13
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A. C. C. Coolen; S. Franz
texts
eye 51
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We use a linear system of Langevin spins with disordered interactions as an exactly solvable toy model to investigate a procedure, recently proposed by Coolen and Sherrington, for closing the hierarchy of macroscopic order parameter equations in disordered spin systems. The closure procedure, based on the removal of microscopic memory effects, is shown to reproduce the correct equations for short times and in equilibrium. For intermediate time-scales the procedure does not lead to the exact...
Source: http://arxiv.org/abs/cond-mat/9406082v1
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51
Sep 23, 2013
09/13
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A. C. Davis; R. Brandenberger; M. Trodden
texts
eye 51
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Electroweak baryogenesis has become a topic of much recent activity [1]. Here we discuss a new scenario which has the advantage of being insensitive to the order of the electroweak phase transition. We briefly review a mechanism [2] using unstable electroweak strings [3] and discuss in detail a mechanism [4] using topological defects (in particular cosmic strings) left behind after a previous phase transition.
Source: http://arxiv.org/abs/hep-ph/9406355v1
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Sep 23, 2013
09/13
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A. C. Scott; J. C. Eilbeck; H. Gilhøj
texts
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The number state method is used to study soliton bands for three anharmonic quantum lattices: i) The discrete nonlinear Schr\"{o}dinger equation, ii) The Ablowitz-Ladik system, and iii) A fermionic polaron model. Each of these systems is assumed to have $f$-fold translational symmetry in one spatial dimension, where $f$ is the number of freedoms (lattice points). At the second quantum level $(n=2)$ we calculate exact eigenfunctions and energies of pure quantum states, from which we...
Source: http://arxiv.org/abs/hep-th/9406147v1
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Sep 23, 2013
09/13
by
A. Calogeracos; Norman Dombey; Geoffrey B. West
texts
eye 46
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This paper is devoted to a study of possible scaling laws, and their logarithmic corrections, occurring in deep inelastic electropion production. Both the exclusive and semi-exclusive processes are considered. Scaling laws, originally motivated from PCAC and current algebra considerations are examined, first in the framework of the parton model and QCD peturbation theory and then from the more formal perspective of the operator product expansion and asymptotic freedom, (as expressed through the...
Source: http://arxiv.org/abs/hep-ph/9406269v1
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Sep 23, 2013
09/13
by
A. Carlini; J. Greensite
texts
eye 49
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We point out that for a large class of parametrized theories, there is a constant in the constrained Hamiltonian which drops out of the classical equations of motion in configuration space. Examples include the mass of a relativistic particle in free fall, the tension of the Nambu string, and Newton's constant for the case of pure gravity uncoupled to matter or other fields. In the general case, the classically irrelevant constant is proportional to the ratio of the kinetic and potential terms...
Source: http://arxiv.org/abs/gr-qc/9406044v1
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Sep 23, 2013
09/13
by
A. Connes; C. Rovelli
texts
eye 55
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We consider the cluster of problems raised by the relation between the notion of time, gravitational theory, quantum theory and thermodynamics; in particular, we address the problem of relating the "timelessness" of the hypothetical fundamental general covariant quantum field theory with the "evidence" of the flow of time. By using the algebraic formulation of quantum theory, we propose a unifying perspective on these problems, based on the hypothesis that in a generally...
Source: http://arxiv.org/abs/gr-qc/9406019v1
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Sep 23, 2013
09/13
by
A. Crisanti; H. -J. Sommers
texts
eye 61
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In this letter we analyze the TAP approach to the spherical $p$-spin spin glass model in zero external field. The TAP free energy is derived by summing up all the relevant diagrams for $N\to\infty$ of a diagrammatic expansion of the free energy. We find that if the multiplicity of the TAP solutions is taken into account, then there is a first order transition in the order parameter at the critical temperature $T_{\rm c}$ higher than that predicted by the replica solution $T_{\rm RSB}$, but in...
Source: http://arxiv.org/abs/cond-mat/9406051v1
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53
Sep 23, 2013
09/13
by
A. Crisanti; H. Rieger
texts
eye 53
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We investigate the zero-temperature quantum phase transition of the random bond Ising chain in a transverse magnetic field. Its critical properties are identical to those of the McCoy-Wu model, which is a classical Ising model in two dimensions with layered disorder. The latter is studied via Monte Carlo simulations and transfer matrix calculations and the critical exponents are determined with a finite-size scaling analysis. The magnetization and susceptibility obey conventional rather than...
Source: http://arxiv.org/abs/cond-mat/9406006v1
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63
Sep 19, 2013
09/13
by
A. Crisanti; U. Marini Bettolo Marconi
texts
eye 63
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In this paper we present a formulation of the nonlinear stochastic differential equation which allows for systematic approximations. The method is not restricted to the asymptotic, i.e., stationary, regime but can be applied to derive effective equations describing the relaxation of the system from arbitrary initial conditions. The basic idea is to reduce the nonlinear Langevin equation to an equivalent equilibrium problem, which can then be studied with the methods of conventional equilibrium...
Source: http://arxiv.org/abs/chao-dyn/9405013v1
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Sep 23, 2013
09/13
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A. D. Martin; R. G. Roberts; W. J. Stirling
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eye 83
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To obtain improved parton densities of the proton, we present a new global analysis of deep inelastic and related data including, in particular, the recent measurements of $F_2$ at HERA, of the asymmetry of the rapidity distributions of $W^\pm$ production at the FNAL $pp$ collider and of the asymmetry in Drell-Yan production in $pp$ and $pn$ collisions. We also incorporate data to determine the flavour dependence of the quark sea distributions. We find that the behaviour of the partons at small...
Source: http://arxiv.org/abs/hep-ph/9406315v1
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35
Sep 23, 2013
09/13
by
A. Denner; S. Dittmaier; G. Weiglein
texts
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Application of the background-field method to QCD and the electroweak Standard Model yields gauge-invariant effective actions giving rise to simple Ward identities. Within this method, we calculate the quantities that have been treated in the literature using the pinch technique. Putting the quantum gauge parameter equal to one, we recover the pinch-technique results as a special case of the background-field method. The one-particle-irreducible Green functions of the background-field method...
Source: http://arxiv.org/abs/hep-ph/9406204v1
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Sep 23, 2013
09/13
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A. Denner; S. Dittmaier; G. Weiglein
texts
eye 39
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Application of the background-field method to the electroweak Standard-Model yields a gauge-invariant effective action giving rise to simple Ward identities. We find that in the background-field `t Hooft-Feynman gauge the resulting vertex functions are exactly those that are obtained using the pinch technique. Thus, the background-field method provides a general framework that generalizes the pinch technique directly and uniquely to arbitrary Green functions and arbitrary orders of perturbation...
Source: http://arxiv.org/abs/hep-ph/9406400v1
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Sep 23, 2013
09/13
by
A. Djouadi
texts
eye 47
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I summarize the prospects for discovering Higgs bosons at future $pp$ and $\ee$ colliders both in the Standard Model and its Minimal Supersymmetric extension.
Source: http://arxiv.org/abs/hep-ph/9406433v1
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Sep 23, 2013
09/13
by
A. Djouadi
texts
eye 79
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The prospects for discovering Higgs particles and studying their fundamental properties at future high-energy electron-positron and hadron colliders are reviewed. Both the Standard Model Higgs boson and the Higgs particles of its minimal supersymmetric extension are discussed. We update various results by taking into account the new value of the top quark mass obtained by the CDF Collaboration and by including radiative corrections some of which have been calculated only recently.
Source: http://arxiv.org/abs/hep-ph/9406430v1
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21
Sep 23, 2013
09/13
by
A. Djouadi; P. Gambino
texts
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We present the QCD corrections to Higgs boson self-energies for arbitrary momentum transfer and for different internal quark masses, to treat the case of CP--even, CP--odd and charged Higgs bosons which appear in extensions of the Standard Model scalar sector. Using Ward Identities, we then relate these results obtained by directly evaluating the relevant two--loop Feynman diagrams to the known expressions for the electroweak vector boson vacuum polarization functions. Finally, we derive the...
Source: http://arxiv.org/abs/hep-ph/9406431v1
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Sep 23, 2013
09/13
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A. Djouadi; P. Gambino
texts
eye 71
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At proton colliders, Higgs particles are dominantly produced in the gluon--gluon fusion mechanism. The Higgs--gluons coupling is mediated by heavy quark loops, and the process can serve to count the number of heavy strongly interacting particles whose masses are generated by the Higgs mechanism. We present the two--loop leading electroweak radiative correction to this coupling, which is quadratically proportional to the heavy quark masses. It turns out thatthis correction is well under control...
Source: http://arxiv.org/abs/hep-ph/9406432v1
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Sep 23, 2013
09/13
by
A. Dobado; A. Lopez
texts
eye 40
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Whichever could be the real theory of gravitation, the corresponding low-energy effective lagrangian will probably contain higher derivative terms. In this work we study the general conditions on those terms in order to produce enough inflation to solve some of the problems of the standard Friedmann-Robertson-Walker cosmology in absence of any inflaton field. We apply our results to some particular scenarios where higher derivative terms appear in the effective lagrangian for gravity like those...
Source: http://arxiv.org/abs/hep-ph/9406409v1
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Sep 23, 2013
09/13
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A. Dotsenko; O. Sushkov
texts
eye 58
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Using the J_1-J_2 model, we present a description of quantum phase transition from Neel ordered to the spin-liquid state based on the modified spin wave theory. The general expression for the gap in the spectrum in the spin-liquid phase is presented.
Source: http://arxiv.org/abs/cond-mat/9406106v2
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Sep 23, 2013
09/13
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A. Erdas; C. W. Kim; J. A. Lee
texts
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We calculate the generational mass splitting of neutrinos in high temperature $SU(2)_{\scriptscriptstyle{L}}\otimes U(1)$ gauge theory when the temperature is above $250$ GeV and the gauge symmetry is restored. We consider the case of neutrinos that are massless at tree level as well as the case of neutrinos with tree-level mass and large mixing.
Source: http://arxiv.org/abs/hep-ph/9406310v1
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Sep 23, 2013
09/13
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A. G. Cohen; D. B. Kaplan; A. E. Nelson
texts
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We include the effects of diffusion in the electroweak spontaneous baryogenesis scenario and show that it can greatly enhance the resultant baryon density, by as much as a factor of $1/\alpha_w^4 \sim 10^6$ over previous estimates. Furthermore, the baryon density produced is rather insensitive to parameters characterizing the first order weak phase transition, such as the width and propagation velocity of the phase boundary.
Source: http://arxiv.org/abs/hep-ph/9406345v1
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Jul 19, 2013
07/13
by
A. González-Ruiz
texts
eye 92
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We consider integrable open--boundary conditions for the supersymmetric t--J model commuting with the number operator $n$ and $S^{z}$. Four families, each one depending on two arbitrary parameters, are found. We find the relation between Sklyanin's method of constructing open boundary conditions and the one for the quantum group invariant case based on Markov traces. The eigenvalue problem is solved for the new cases by generalizing the Nested Algebraic Bethe ansatz of the quantum group...
Source: http://arxiv.org/abs/hep-th/9401118v2
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Sep 23, 2013
09/13
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A. H. Castro Neto; H. Q. Lin; H. -Y Chen; J. M. P. Carmelo
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We write the Hamiltonian of the Bose gas with two-body repulsive $\delta$-function potential in a pseudoparticle operator basis which diagonalizes the problem via the Bethe ansatz. In this operator basis the original bosonic interactions are represented by zero-momentum forward-scattering interactions between Landau-liquid pseudoparticles. We find that this pseudoparticle operator algebra is complete: {\it all} the Hamiltonian eigenstates are generated by acting pseudoparticle operators on the...
Source: http://arxiv.org/abs/cond-mat/9406044v1
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Sep 23, 2013
09/13
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A. H. Chamseddine; J. Fröhlich
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A general definition of Chern-Simons actions in non-commutative geometry is proposed and illustrated in several examples. These are based on ``space-times'' which are products of even-dimensional, Riemannian spin manifolds by a discrete (two-point) set. If the *algebras of operators describing the non-commutative spaces are generated by functions over such ``space-times'' with values in certain Clifford algebras the Chern-Simons actions turn out to be the actions of topological gravity on the...
Source: http://arxiv.org/abs/hep-th/9406013v1
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Jul 19, 2013
07/13
by
A. Hanany; Y. Oz; M. R. Plesser
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We construct a topological Landau-Ginzburg formulation of the two-dimensional string at the self-dual radius. The model is an analytic continuation of the $A_{k+1}$ minimal model to $k=-3$. We compute the superpotential and calculate tachyon correlators in the Landau-Ginzburg framework. The results are in complete agreement with matrix model calculations. We identify the momentum one tachyon as the puncture operator, non-negative momentum tachyons as primary fields, and negative momentum ones...
Source: http://arxiv.org/abs/hep-th/9401030v3
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Sep 23, 2013
09/13
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A. Hoffmann; P. Lemmens; G. Guentherodt; V. Thomas; K. Winzer
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Single crystalline Tl2Ba2Ca2Cu3O10 was studied using electronic Raman scattering. The renormalization of the scattering continuum was investigated as a function of the scattering geometry to determine the superconducting energy gap 2Delta(k). The A1g- and B2g-symmetry component show a linear frequency behaviour of the scattering intensity with a peak related to the energy gap, while the B1g-symmetry component shows a characteristic behaviour at higher frequencies. The observed frequency...
Source: http://arxiv.org/abs/cond-mat/9406027v1
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41
Sep 23, 2013
09/13
by
A. Hulsebos; C. P. Korthals-Altes; S. Nicolis
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We study abelian gauge theories with anisotropic couplings in $4+D$ dimensions. A layered phase is present, in the absence as well as in the presence of fermions. A line of second order transitions separates the layered from the Coulomb phase, if $D\leq 3$.
Source: http://arxiv.org/abs/hep-th/9406003v1
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41
Sep 23, 2013
09/13
by
A. Hädicke; W. Krech
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The effect of a high--frequency microwave irradiation on the averaged stationary charge in a single--electron tunneling box (SET--box) with superconducting island is investigated. The resulting $\langle Q\rangle$--$Q_g$ characteristics are modified compared with those from the well--known constant voltage--driven box. It can be shown that there is a cross--over from the 2e--periodic regime in $Q_g$ corresponding to the parity effect to 1e--periodic behavior not only with increasing temperature...
Source: http://arxiv.org/abs/cond-mat/9406065v1
