79 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "71 Classical And Quantum Mechanics, General Physics"  
Results: 1 - 24 next
open access

The theory of hybrid stochastic algorithms

Description: These lectures introduce the family of Hybrid Stochastic Algorithms for performing Monte Carlo calculations in Quantum Field Theory. After explaining the basic concepts of Monte Carlo integration we discuss the properties of Markov processes and one particularly useful example of them: the Metropolis algorithm. Building upon this framework we consider the Hybrid and Langevin algorithms from the viewpoint that they are approximate versions of the Hybrid Monte Carlo method; and thus we are led to… more
Date: November 21, 1989
Creator: Kennedy, A.D. (Florida State Univ., Tallahassee, FL (USA). Supercomputer Computations Research Inst.)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Lunar radionuclide records of average solar-cosmic-ray fluxes over the last ten million years

Description: Because changes in solar activity can modify the fluxes of cosmic-ray particles in the solar system, the nature of the galactic and solar cosmic rays and their interactions with matter are described and used to study the ancient sun. The use of cosmogenic nuclides in meteorites and lunar samples as detectors of past cosmic-ray variations are discussed. Meteorite records of the history of the galactic cosmic rays are reviewed. The fluxes of solar protons over various time periods as determined f… more
Date: March 21, 1980
Creator: Reedy, R. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Center-stabilized Yang-Mills Theory:Confinement and Large N Volume Independence

Description: We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N{sup 2}) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if t… more
Date: March 21, 2008
Creator: Unsal, Mithat; /SLAC /Stanford U., Phys. Dept.; Yaffe, Laurence G. & /Washington U., Seattle
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Stability of Galactic Gaseous Disks and the Formation of Massive Clusters

Description: We study gravitational instabilities in disks, with special attention to the most massive clumps that form because they are expected to be the progenitors of globular-type clusters. The maximum unstable mass is set by rotation and depends only on the surface density and orbital frequency of the disk. We propose that the formation of massive clusters is related to this largest scale in galaxies not stabilized by rotation. Using data from the literature, we predict that globular-like clusters can… more
Date: August 21, 2008
Creator: Escala, Andres & Larson, Richard B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Measurement of |Vcb| and the Form-Factor Slope for BBar -> Dlnu Decays on the Recoil of Fully Reconstructed B Mesons

Description: We present a measurement of the CKM matrix element |V{sub cb}| and the form-factor slope {rho}{sup 2} for {bar B} {yields} D{ell}{sup -} {bar {nu}}{sub {ell}} decays based on 417 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector. The semileptonic decays are selected in B{bar B} events in which the hadronic decay of the second B meson is fully reconstructed. From the measured differential decay rate of the signal decay we determine G(1)|V{sub cb}| = (43.0 {+-} 1… more
Date: August 21, 2008
Creator: Aubert, B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)

Description: The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also tr… more
Date: April 21, 2008
Creator: Karsch, F.; Kharzeev, D.; Molnar, K.; Petreczky, P. & Teaney, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

New Quarkonium Results from the BABAR experiment

Description: New BABAR results on B mesons and quarkonia are presented: an analysis of B{sup +} {yields} X(3872)K{sup +} and B{sup 0} {yields} X(3872)K{sup 0} decays with X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -}, a precise measurement of the B mass difference {Delta}m{sub B} = m(B{sup 0}) -m(B{sup +}) and a study of hadronic transition between {Upsilon} mesons.
Date: May 21, 2008
Creator: Arnaud, Nicolas & Collaboration, representing the BABAR
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

LCPT: a program for finding linear canonical transformations. [In MACSYMA]

Description: This article describes a MACSYMA program to compute symbolically a canonical linear transformation between coordinate systems. The difficulties in implementation of this canonical small physics problem are also discussed, along with the implications that may be drawn from such difficulties about widespread MACSYMA usage by the community of computational/theoretical physicists.
Date: May 21, 1979
Creator: Char, B.W. & McNamara, B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Tests of prototype SSC (Superconducting Super Collider) magnets

Description: Results are presented from tests of the third full scale development dipole magnet for the Superconducting Super Collider and from a retest of a 4.5 m model magnet of the same design mounted in an SSC cryostat. The 4.5 m magnet shows consistent quench performance between its original tests in boiling liquid helium in a vertical dewar and the current tests in forced flow helium in a horizontal cryostat. Little or no retraining is observed over several thermal cycles. The full length magnet requi… more
Date: September 21, 1987
Creator: Strait, J.; Brown, B.C.; Hanft, R.; Koepke, K.; Kuchnir, M.; Lundy, R. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Theoretical models for supernovae

Description: The results of recent numerical simulations of supernova explosions are presented and a variety of topics discussed. Particular emphasis is given to (i) the nucleosynthesis expected from intermediate mass (10sub solar less than or equal to M less than or equal to 100 Msub solar) Type II supernovae and detonating white dwarf models for Type I supernovae, (ii) a realistic estimate of the ..gamma..-line fluxes expected from this nucleosynthesis, (iii) the continued evolution, in one and two dimens… more
Date: September 21, 1981
Creator: Woosley, S. E. & Weaver, T. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Particle physics---Experimental

Description: We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for devel… more
Date: August 21, 1991
Creator: Lord, J.J.; Boynton, P.E.; Burnett, T.H. & Wilkes, R.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final report covering work done under LLL P. O. No. 4165009

Description: The High Field Test Facility (HFTF) to be built at Lawrence Livermore Laboratories (LLL) consists of a magnet which will be wound with Nb/sub 3/Sn superconductor. Embossed and electroplated copper strip will be soldered to the two broad sides of a rectangular Nb/sub 3/Sn superconductor 5.4 mm x 11.0 mm x approximately 100 m long. It is the purpose of this project to upgrade existing facilities to emboss the copper stabilizer strip, electroplate the strip with 50 Pb-50 Sn solder, and to solder t… more
Date: September 21, 1979
Creator: Spencer, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Computations of quenching and stability in a CICC (cable-in-conduit conductor) conductor

Description: The quenching and stability behavior of forced-flow helium-cooled, cable-in-conduit conductors (CICC) has been analyzed using a new computer program. This computer analysis code was developed for performing general, transient, thermal analyses on CICCs. The program includes the necessary details for the physical properties of all the constituent materials of such conductors, and accurately models the thermo- and fluid-dynamic behavior of the helium coolant starting from a wide range of initial … more
Date: September 21, 1990
Creator: Wong, R.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

General Dynamics Convair Division approach to structural analysis of large superconducting coils

Description: Most of the procedures and techniques described were developed over the past three years. Starting in late 1976, development began on high-accuracy computer codes for electromagnetic field and force analysis. This effort resulted in completion of a family of computer programs called MAGIC (MAGnetic Integration Calcaultion). Included in this group of programs is a post-processor called POSTMAGIC that links MAGIC to GDSAP (General Dynamics Structural Analysis Program) by automatically transferrin… more
Date: March 21, 1979
Creator: Baldi, R.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Particle Physics---Experimental. Annual Progress Report

Description: We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for devel… more
Date: August 21, 1991
Creator: Lord, Jere J.; Boynton, P. E.; Burnett, T. H. & Wilkes, R. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An analytical electron distribution function for inelastic collisions in a uniform gas with time varying electric field

Description: The desire for improved control over electric discharge phenomena in a wide variety of scientific, technological, manufacturing, and waste processing activities spurs the development of non-equilibrium, non-uniform, and time dependent models. This paper addresses the situation of slightly ionized, spatially uniform gas with a time varying electric field, and in which inelastic collisions occur. The purpose here is to present a reasonably consistent, and reasonably accessible analytical result f… more
Date: July 21, 1994
Creator: Garcia, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Speckle Imaging Over Horizontal Paths

Description: Atmospheric aberrations reduce the resolution and contrast in surveillance images recorded over horizontal or slant paths. This paper describes our recent horizontal and slant path imaging experiments of extended scenes as well as the results obtained using speckle imaging. The experiments were performed with an 8-inch diameter telescope placed on either a rooftop or hillside and cover ranges of interest from 0.5 km up to 10 km. The scenery includes resolution targets, people, vehicles, and oth… more
Date: May 21, 2002
Creator: Carrano, C J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Infrared Spectra of High Pressure Carbon Monoxide

Description: We report infrared (IR) spectroscopic measurements of carbon monoxide (CO) at high pressures. Although CO is one of the simplest heteronuclear diatomic molecules, it displays surprisingly complex behavior at high pressures and has been the subject of several studies [1-5]. IR spectroscopic studies of high pressures phases of CO provide data complementing results from previous studies and elucidating the nature of these phases. Though a well-known and widely utilized diagnostic of molecular syst… more
Date: September 21, 2001
Creator: Evans, W. J.; Lipp, M. J. & Lorenzana, H. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Blue and Green Light? Wavelength Scaling for NIF

Description: Use of the National Ignition Facility to also output frequency-doubled (.53{micro}m) laser light would allow significantly more energy to be delivered to targets as well as significantly greater bandwidth for beam smoothing. This green light option could provide access to new ICF target designs and a wider range of plasma conditions for other applications. The wavelength scaling of the interaction physics is a key issue in assessing this green light option. Wavelength scaling theory based on th… more
Date: August 21, 2003
Creator: Suter, L.; Miller, M.; Moody, J. & Kruer, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

MATRIX PRODUCT VARIATIONAL FORMULATION FOR LATTICE GAUGE THEORY.

Description: For hamiltonian lattice gauge theory, we introduce the matrix product ansatz inspired from density matrix renormalization group. In this method, wavefunction of the target state is assumed to be a product of finite matrices. As a result, the energy becomes a simple function of the matrices, which can be evaluated using a computer. The minimum of the energy function corresponds to the vacuum state. We show that the S = 1/2 Heisenberg chain model are well described with the ansatz. The method is … more
Date: September 21, 2004
Creator: SUGIHARA,T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Laser System for Photoelectron and X-Ray Production in the PLEIADES Compton Light Source

Description: The PLEIADES (Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures) facility provides tunable short x-ray pulses with energies of 30-140 keV and pulse durations of 0.3-5 ps by scattering an intense, ultrashort laser pulse off a 35-75 MeV electron beam. Synchronization of the laser and electron beam is obtained by using a photoinjector gun, and using the same laser system to generate the electrons and the scattering laser. The Ti Ti:Sapphire, chirped pulse amplification… more
Date: April 21, 2005
Creator: Gibson, D J; Barty, C J; Betts, S M; Crane, J K & Jovanovic, I
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Method of independent timesteps in the numerical solution of initial value problems

Description: In the numerical solution of initial-value problems in several independent variables, the timestep is controlled, especially in the presence of shocks, by a small portion of the logical mesh, what one may call the crisis zone. One is frustrated by the necessity of doing in the whole mesh frequent calculations required by only a small part of the mesh. It is shown that it is possible to choose different timesteps natural to different parts of the mesh and to advance each zone in time only as oft… more
Date: July 21, 1976
Creator: Porter, A. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Unification and extension of the similarity scaling criteria and mixing transition for studying astrophysics using high energy density laboratory experiments or numerial simulations

Description: The Euler similarity criteria for laboratory experiments and time-dependent mixing transition are important concepts introduced recently for application to prediction and analysis of astrophysical phenomena. However Euler scaling by itself provides no information on the distinctive spectral range of high Reynolds number turbulent flows found in astrophysics situations. On the other hand, time-dependent mixing transition gives no indication on whether a flow that just passed the mixing transitio… more
Date: August 21, 2006
Creator: Zhou, Y
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen