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- Brown dwarfs – planetary systems – open clusters and associations: general – open clusters and associations: individual: NGC 6819 (1)
- Building balance point (1)
- Energy lossiness (1)
- Free temperature (1)
- Galaxies: active — galaxies: jets — quasars: individual (3C 279) — radiation mechanisms: nonthermal — radio continuum: galaxies (1)
Articles 1 - 19 of 19
Full-Text Articles in Physical Sciences and Mathematics
Pion-Kaon Correlations In Central Au+Au Collisions At √SNn=130 Gev, Star Collaboration, T.D. Gutierrez
Pion-Kaon Correlations In Central Au+Au Collisions At √SNn=130 Gev, Star Collaboration, T.D. Gutierrez
Physics
Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at √sNN=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.
Three-Pion Hanbury Brown–Twiss Correlations In Relativistic Heavy-Ion Collisions From The Star Experiment, Star Collaboration, T.D. Gutierrez
Three-Pion Hanbury Brown–Twiss Correlations In Relativistic Heavy-Ion Collisions From The Star Experiment, Star Collaboration, T.D. Gutierrez
Physics
Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at √sNN=130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freeze-out. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.
Energy Scaling Law For Buildings, David W. Hafemeister
Energy Scaling Law For Buildings, David W. Hafemeister
Physics
This paper is an ode to my friend Hendrik. We collaborated on hyperfine interactions from 1962 to 1984, when he was colleague and friend. Since then I have been working on the Physics of Societal Issues (Springer Verlag, 2003). The paper below models energy use in buildings, which could save considerable energy with well-designed buildings.
Biological Permanent Magnets, Richard B. Frankel
Biological Permanent Magnets, Richard B. Frankel
Physics
Magnetotactic bacteria orient and migrate along magnetic field lines. Each cell is essentially a self-propelled magnetic dipole. The magnetic properties of these bacteria have been determined by a variety of techniques, including pulsed hysteresis measurements on single cells.
Computer-Controlled In-Class Feedback System For Interactive Lectures, Thomas J. Bensky
Computer-Controlled In-Class Feedback System For Interactive Lectures, Thomas J. Bensky
Physics
Instructors who wish to implement an interactive lecture style, such as peer instruction, have the need to collect feedback from students in a lecture environment. We present a computer-controlled electronic circuit that allows for quick, rigorous, and accurate measurement and reporting of student feedback in the lecture environment.
Net Charge Fluctuations In Au+Au Collisions At √SNn=130 Gev, Star Collaboration, T.D. Gutierrez
Net Charge Fluctuations In Au+Au Collisions At √SNn=130 Gev, Star Collaboration, T.D. Gutierrez
Physics
We present the results of charged particle fluctuations measurements in Au+Au collisions at √sNN=130 GeV using the STAR detector. Dynamical fluctuations measurements are presented for inclusive charged particle multiplicities as well as for identified charged pions, kaons, and protons. The net charge dynamical fluctuations are found to be large and negative providing clear evidence that positive and negative charged particle production is correlated within the pseudorapidity range investigated. Correlations are smaller than expected based on model-dependent predictions for a resonance gas or a quark-gluon gas which undergoes fast hadronization and freeze-out. Qualitative agreement is found with comparable scaled …
New Results From The Cryogenic Dark Matter Search Experiment, D. S. Akerib, J. Alvaro-Dean, M. S. Armel, M. J. Attisha, L. Baudis, D. A. Bauer, A. I. Bolozdynya, P. L. Brink, R. Bunker, Blas Cabrera, D. O. Caldwell, J. P. Castle, C. L. Chang, R. M. Clarke, M. B. Crisler, P. Crushman, A. K. Davies, R. Dixon, D. D. Driscoll, L. Duong, J. Emes, R. Ferril, R. J. Gaitskell, S. R. Golwala, M. Haldeman, J. Hellmig, M. Hennessey, D. Holmgren, M. E. Huber, S. Kamat, M. Kurylowicz, A. Lu, R. Mahapatra, V. Mandic, J. M. Martinis, P. Meunier, N. Mirabolfathi, S. W. Nam, H. Nelson, R. Nelson, R. W. Ogburn, J. Perales, T. A. Perera, M. C. Perillo Isaac, W. Rau, A. Reisetter, R. R. Ross, T. Saab, B. Sadoulet, J. Sander, C. Savage, R. W. Schnee, D. N. Seitz, T. A. Shutt, G. Smith, A. L. Spadafora, J.-P. F. Thompson, A. Tomada, G. Wang, S. Yellin, Betty A. Young
New Results From The Cryogenic Dark Matter Search Experiment, D. S. Akerib, J. Alvaro-Dean, M. S. Armel, M. J. Attisha, L. Baudis, D. A. Bauer, A. I. Bolozdynya, P. L. Brink, R. Bunker, Blas Cabrera, D. O. Caldwell, J. P. Castle, C. L. Chang, R. M. Clarke, M. B. Crisler, P. Crushman, A. K. Davies, R. Dixon, D. D. Driscoll, L. Duong, J. Emes, R. Ferril, R. J. Gaitskell, S. R. Golwala, M. Haldeman, J. Hellmig, M. Hennessey, D. Holmgren, M. E. Huber, S. Kamat, M. Kurylowicz, A. Lu, R. Mahapatra, V. Mandic, J. M. Martinis, P. Meunier, N. Mirabolfathi, S. W. Nam, H. Nelson, R. Nelson, R. W. Ogburn, J. Perales, T. A. Perera, M. C. Perillo Isaac, W. Rau, A. Reisetter, R. R. Ross, T. Saab, B. Sadoulet, J. Sander, C. Savage, R. W. Schnee, D. N. Seitz, T. A. Shutt, G. Smith, A. L. Spadafora, J.-P. F. Thompson, A. Tomada, G. Wang, S. Yellin, Betty A. Young
Physics
Using improved Ge and Si detectors, better neutron shielding, and increased counting time, the Cryogenic Dark Matter Search (CDMS) experiment has obtained stricter limits on the cross section of weakly interacting massive particles (WIMPs) elastically scattering from nuclei. Increased discrimination against electromagnetic backgrounds and reduction of the neutron flux confirm WIMP-candidate events previously detected by CDMS were consistent with neutrons and give limits on spin-independent WIMP interactions which are >2× lower than previous CDMS results for high WIMP mass, and which exclude new parameter space for WIMPs with mass between 8 and 20 GeV/c2 .
Ξ‾ And Ω Distributions In Hadron–Nucleus Interactions, R. Vogt, Thomas D. Gutierrez
Ξ‾ And Ω Distributions In Hadron–Nucleus Interactions, R. Vogt, Thomas D. Gutierrez
Physics
Strange baryons have long been known to exhibit a leading particle effect. A recent comparison of Ξ‾ production in π‾, n, and Σ‾ interactions with nuclei show this effect clearly. These data are supplemented by earlier measurements of Ξ‾ and Ω production by a Ξ‾ beam. We calculate the Ξ‾ and Ω xF distributions and nuclear dependence in hA interactions using the intrinsic model.
Resistive Transitions In Quench-Condensed Bi Films Near A Normal-Metal Ground Plane, Richard P. Barber Jr., Ben Kain
Resistive Transitions In Quench-Condensed Bi Films Near A Normal-Metal Ground Plane, Richard P. Barber Jr., Ben Kain
Physics
We report observations of the zero-field resistive transitions of superconducting quench-condensed Bi0.97Tl0.03 films both near electrically isolated normal-metal ground planes and on clean fire-polished glass. Transition temperatures, obtained by fitting the data with the two-dimensional Aslamazov-Larkin theory of fluctuation conductance, were found to be significantly enhanced for films deposited over ground planes versus those deposited onto insulating substrates. Conductivity enhancement due to superconducting fluctuations was found to be much less than expected for the thinnest samples. This suppression was coincident with broadened superconductor transitions that are consistent with nonuniform sample thickness. Sufficiently thick films showed reasonable agreement with both the …
Application Of Interferometric Wave Propagation For Refractive Index Measurements Of Solids, Glen D. Gillen, Shekhar Guha
Application Of Interferometric Wave Propagation For Refractive Index Measurements Of Solids, Glen D. Gillen, Shekhar Guha
Physics
The output signal of a modified Michelson interferometer with a flat-parallel sample, whose normal is oriented at an arbitrary angle with respect to the laser path, placed in one arm is analyzed. The interferometric pattern as a function of angle is calculated, and used to determine the absolute refractive index.
Analysis Of Resonance Structure In The Above-Threshold Ionization Photoelectron Spectra Of Magnesium, Glen D. Gillen, L D. Van Woerkom
Analysis Of Resonance Structure In The Above-Threshold Ionization Photoelectron Spectra Of Magnesium, Glen D. Gillen, L D. Van Woerkom
Physics
Using high-resolution photoelectron spectroscopy and 120-fs, 800-nm Ti:sapphire laser pulses, we observe and analyze intensity-dependent resonant population of specific intermediate excited states of neutral magnesium atoms and their subsequent photoionization in the laser field. Various participating states are identified using angular-momentum selection rules, partial yields, and angular distributions. Several unexpected results are observed and discussed, including peaks that do not correspond to expected resonant processes, and order-to-order variations in the photoelectron spectra.
Driven Depinning Of Strongly Disordered Media And Anisotropic Mean-Field Limits, M. Christina Marchetti, A. Alan Middleton, Karl Saunders, J. M. Schwarz
Driven Depinning Of Strongly Disordered Media And Anisotropic Mean-Field Limits, M. Christina Marchetti, A. Alan Middleton, Karl Saunders, J. M. Schwarz
Physics
Extended systems driven through strong disorder are modeled generically using coarse-grained degrees of freedom that interact elastically in the directions parallel to the drive and slip along at least one of the directions transverse to the motion. In the limit of infinite-range elastic and viscous coupling this model has a tricritical point separating a region where the depinning is continuous, in the universality class of elastic depinning, from a region where depinning is hysteretic. Many of the collective transport models discussed in the literature are special cases of the generic model.
Radio Polarization Of The Young High-Magnetic-Field Pulsar Psr J1119-6127, Fronefield Crawford, Nathan C. Keim
Radio Polarization Of The Young High-Magnetic-Field Pulsar Psr J1119-6127, Fronefield Crawford, Nathan C. Keim
Physics
We have investigated the radio polarization properties of PSR J1119-6127, a recently discovered young radio pulsar with a large magnetic field. Using pulsar-gated radio imaging data taken at a center frequency of 2496 MHz with the Australia Telescope Compact Array, we have determined a rotation measure for the pulsar of +842 +/- 23 rad m^-2. These data, combined with archival polarimetry data taken at a center frequency of 1366 MHz with the Parkes telescope, were used to determine the polarization characteristics of PSR J1119-6127 at both frequencies. The pulsar has a fractional linear polarization of ~75% and ~55% at 1366 …
Review Of Tritium On Ice: The Dangerous New Alliance Of Nuclear Weapons And Nuclear Power By Kenneth D. Bergeron, David W. Hafemeister
Review Of Tritium On Ice: The Dangerous New Alliance Of Nuclear Weapons And Nuclear Power By Kenneth D. Bergeron, David W. Hafemeister
Physics
No abstract provided.
Searching For Planetary Transits In The Field Of Open Cluster Ngc 6819 – I, R. A. Street, Keith Horne, T. A. Lister, A. Penny, Y. Tsapras, A. Quirrenbach, N. Safizadeh, David Mitchell, J. Cooke, A. Collier Cameron
Searching For Planetary Transits In The Field Of Open Cluster Ngc 6819 – I, R. A. Street, Keith Horne, T. A. Lister, A. Penny, Y. Tsapras, A. Quirrenbach, N. Safizadeh, David Mitchell, J. Cooke, A. Collier Cameron
Physics
We present results from our survey for planetary transits in the field of the intermediate-age (∼2.5 Gyr), metal-rich ([Fe/H] ∼+0.07) open cluster NGC 6819. We have obtained high-precision time-series photometry for over 38 000 stars in this field and have developed an effective matched-filter algorithm to search for photometric transits. This algorithm identified 8 candidate stars showing multiple transit-like events, plus 3 stars with single eclipses. On closer inspection, while most are shown to be low-mass stellar binaries, some of these events could be the result of brown dwarf companions. The data for one of the single-transit candidates indicate a …
Electrical And Spectroscopic Studies Of The Effects Of Dc Electric Fields On Pre-Mixed Propane-Air Flames, S D. Marcum, G D. Gillen, B N. Ganguly
Electrical And Spectroscopic Studies Of The Effects Of Dc Electric Fields On Pre-Mixed Propane-Air Flames, S D. Marcum, G D. Gillen, B N. Ganguly
Physics
The effects of DC electric fields on temperature distributions within pre-mixed propane-air flames have been measured by the technique of thin filament pyrometry (TFP). We have focussed on the dramatic electric-field-induced modifications of the shape and size of the inner cone and the concomitant changes in the temperature profiles of fuel-rich mixtures with equivalence ratios of 1-1.35. Temperature profile measurements show large decreases in the reaction zone volume that is dependent upon the applied voltage polarity, indicating that electron impact excitation is not responsible for the observed effects. Additionally, the observed flame temperature profile modifications are not strongly dependent on …
Us Nuclear Security Cooperation With Russia And Transparency, David W. Hafemeister
Us Nuclear Security Cooperation With Russia And Transparency, David W. Hafemeister
Physics
This chapter reviews the efforts of Russia and the United States to conclude agreements on the control or reduction of their inventories of nuclear warheads and military fissile materials. While some of the negotiations attempted to codify arms limitation and reduction measures, others were aimed at constraining the spread of fissile materials and technologies to the non-nuclear weapon states (NNWS). A number of the negotiations had elements of both arms control and non-proliferation.
Most of the monitoring provisions contained in nuclear agreements between Russia and the USA are in the category of transparency measures—those that give confidence that a …
Measurement Of The Index Of Refraction Of A Flat Zinc Germanium Phosphide Wafer In The Infrared, Glen Gillen, Shekhar Guha
Measurement Of The Index Of Refraction Of A Flat Zinc Germanium Phosphide Wafer In The Infrared, Glen Gillen, Shekhar Guha
Physics
We have developed and tested a novel application of interferometry to determine the absolute refractive index of individual infrared materials having flat and parallel surfaces without alteration of the sample in any way, and measured no for ZnGeP2.
The Speed And Orientation Of The Parsec-Scale Jet In 3c 279, B. Glenn Piner, Stephen C. Unwind, Ann E. Wehrle, Alma C. Zook, C. Megan Urry, Diane M. Gilmore
The Speed And Orientation Of The Parsec-Scale Jet In 3c 279, B. Glenn Piner, Stephen C. Unwind, Ann E. Wehrle, Alma C. Zook, C. Megan Urry, Diane M. Gilmore
Physics
A high degree of relativistic beaming is inferred for the jets of blazars on the basis of several lines of evidence, but the intrinsic speed and angle of the jet to the line of sight for individual sources are difficult to measure. We have calculated inverse Compton Doppler factors for 3C 279 using the collection of VLBI data (including high-resolution space VLBI data at low frequencies) recently published by us (as Wehrle et al. and Piner et al.) and the collection of multiwavelength spectra recently published by Hartman et al. From the Doppler factor and superluminal apparent speed, we then …