Digital Commons Network^™

Observation Of Diffractive J/Ψ Production At The Fermilab Tevatron, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report the first observation of diffractive J/ψ(→μ⁺μ^-) production in p̅p collisions at √s= 1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum p_{T,/sub> ^μ> 2 GeV/c within the pseudorapidity region |η| J/ψ production rates is found to be RJ/ψ=[1.45 ± 0.25]%. The ratio RJ/ψ(x) is presented as a function of x-Bjorken. By combining it with our previously measured corresponding ratio Rjj(x) for diffractive dijet production, we extract a value of 0.59 …}

Gravitational Ultrarelativistic Interaction Of Classical Particles In The Context Of Unification Of Interactions, R. Plyatsko, Oleksa-Myron Bilaniuk

Physics & Astronomy Faculty Works

The response of the ultrarelativistic particle with spin in a Schwarzschild field to the gravitomagnetic components as measured by the comoving observer is investigated. The dependence of the particle's spin–orbit acceleration on the Lorentz γ-factor and the spin orientation is studied. The concrete circular ultrarelativistic orbit of radius r = 3 m is considered as a partial solution of the Mathisson–Papapetrou equations and as the corresponding high-energy quantum state of the Dirac particle. Numerical estimates for protons and electrons near black holes are given. A tendency of gravitational and electromagnetic interactions to approach in quantitative terms at ultrarelativistic velocities is …

Search For Quark-Lepton Compositeness And A Heavy W′ Boson Using The Eν Channel In Pp̅ Collisions At √S = 1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present searches for quark-lepton compositeness and a heavy W′ boson at high electron-neutrino transverse mass. We use ~110 pb^-1 of data collected in pp̅ collisions at √s= 1.8 TeV by the CDF Collaboration during 1992–1995. The data are consistent with standard model expectations. Limits are set on the quark-lepton compositeness scale Λ, the ratio of partial cross sections σ (W′ → eν)/ σ (W → eν), and the mass of a W′ boson with standard model couplings. We exclude Λ< 2.81 TeV and a W′ boson with mass below 754 GeV/c² at the 95% …

Reduced Order Modeling For High Speed Flows With Moving Shocks, David J. Lucia

Theses and Dissertations

The use of Proper Orthogonal Decomposition (POD) for reduced order modeling (ROM) of fluid problems is extended to high-speed compressible fluid flows. The challenge in using POD for high-speed flows is presented by the presence of moving discontinuities in the flow field. To overcome these difficulties, a domain decomposition approach is developed that isolates the region containing the moving shock wave for special treatment. The domain decomposition implementation produces internal boundaries between the various domain sections. The domains are linked using optimization-based solvers which employ constraints to ensure smoothness in overlapping portions of the internal boundary. This approach is applied …

Effects Of A Large Mesospheric Temperature Enhancement On The Hydroxyl Rotational Temperature As Observedfrom The Ground, S. M.L. Melo, R. P. Lowe, W. R. Pendleton Jr., Michael J. Taylor, B. Williams, C. Y. She

All Physics Faculty Publications

The rotational temperature obtained from the rotational population distribution in the bands of the hydroxyl airglow has been shown to be a suitable proxy for the temperature at a height of 87 km [She and Lowe, 1998]. In this paper we examine in detail simultaneous observations on November 2–3, 1997, at Fort Collins, Colorado (41°N, 105°W), with both a sodium temperature lidar and the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) OH mesospheric temperature mapper during which significant differences between the hydroxyl and lidar temperatures occur. The large differences are associated with a major temperature enhancement in the region …

Techniques For The Regeneration Of Wideband Speech From Narrowband Speech, Jason A. Fuemmeler, Russell C. Hardie, William R. Gardner

Electrical and Computer Engineering Faculty Publications

This paper addresses the problem of reconstructing wideband speech signals from observed narrowband speech signals. The goal of this work is to improve the perceived quality of speech signals which have been transmitted through narrowband channels or degraded during acquisition. We describe a system, based on linear predictive coding, for estimating wideband speech from narrowband. This system employs both previously identified and novel techniques. Experimental results are provided in order to illustrate the system’s ability to improve speech quality. Both objective and subjective criteria are used to evaluate the quality of the processed speech signals.

Electronic-Structure Modifications Induced By Surface Segregation In La0.65Pb0.35Mno3 Thin Films, C.N. Borca, B. Xu, T. Komesu, H.-K. Jeong, M.T. Liu, Sy_Hwang Liou, Shane Stadler, Y. Idzerda, Peter A. Dowben

Sy-Hwang Liou Publications

Using spin-polarized inverse photoemission and X-ray absorption spectroscopy techniques, we show that the electronic structure of La_0.65Pb_0.35MnO₃ thin films depends on the composition at the surface. With a gentle annealing procedure, the surface provides a maximum of 80% spin asymmetry at 0.5 eV above the Fermi level in spite of extensive Pb segregation. A heavily annealed (restructured) surface exhibits a reduced surface "ordering" temperature of 240 K (compared to the approximately 335 K bulk value) as well as a reduced spin asymmetry value of 40% at 0.5 eV above Fermi energy.

The Cataclysmic Variable Cw 1045+525: A Secondary-Dominated Dwarf Nova?, C. Tappert, J. R. Thorstensen, W. H. Fenton, N. Bennert, L. Schmidtobreick, A. Bianchini

Physics

We present spectroscopic and photometric observations of the cataclysmic variable CW 1045+525. Both the optical spectrum and the photometric lightcurve show a strong contribution of a K5V-M0V secondary. We derive an orbital period d by measuring the radial velocities of the absorption lines of the secondary. The period and spectral type of the secondary suggest a distance of 350-700 pc. There is evidence for additional sources of line- and continuum emission, but no direct evidence of an accretion disc. We discuss several scenarios for the nature of CW 1045+525 on the basis of our results, finding a dwarf nova classification …

Tachyonic Instability And Dynamics Of Spontaneous Symmetry Breaking, Gary Felder, Lev Kofman, Andrei Linde

Physics: Faculty Publications

Spontaneous symmetry breaking usually occurs due to the tachyonic (spinodal) instability of a scalar field near the top of its effective potential at φ=0. Naively, one might expect the field φ to fall from the top of the effective potential and then experience a long stage of oscillations with amplitude O(v) near the minimum of the effective potential at φ=v until it gives its energy to particles produced during these oscillations. However, it was recently found that the tachyonic instability rapidly converts most of the potential energy V(0) into the energy of colliding classical waves of the scalar field. This …

Magnetite Morphology And Life On Mars, Peter R. Buseck, Rafal E. Dunin-Borkowski, Bertrand Devouard, Richard B. Frankel, Martha R. Mccartney, Paul A. Midgley, Mihály Pósfai, Mathew Weyland

Physics

Nanocrystals of magnetite (Fe₃O₄) in a meteorite from Mars provide the strongest, albeit controversial, evidence for the former presence of extraterrestrial life. The morphological and size resemblance of the crystals from meteorite ALH84001 to crystals formed by certain terrestrial bacteria has been used in support of the biological origin of the extraterrestrial minerals. By using tomographic and holographic methods in a transmission electron microscope, we show that the three-dimensional shapes of such nanocrystals can be defined, that the detailed morphologies of individual crystals from three bacterial strains differ, and that none uniquely match those reported from …

Charged-Particle Multiplicity Pp̅ Collisions At √S = 1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a measurement of the mean charged-particle multiplicity of jets in dijet events with dijet masses in the range 80-630 GeV/c², produced at the Tevatron in pp̅ collisions with √s= 1.8 TeV and recorded by the Collider Detector at Fermilab. The data are fit to perturbative-QCD calculations carried out in the framework of the modified leading log approximation and the hypothesis of local parton-hadron duality. The fit yields values for two parameters in that framework: the ratio of parton multiplicities in gluon and quark jets, r=N^g-jet _partons/N^q-jet _partons =1.7 ± …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 8/16/01- 11/15/01, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible. The process involves evacuation of the furnace. The evacuation of the furnace also evacuates quartz rods used as fuel pin molds. Once evacuated the open ends of the molds are lowered into the melt; the casting furnace is then rapidly pressurized, forcing the molten metal up into the evacuated molds where solidification occurs.

This process works well …

Quantum Anomaly In Molecular Physics, Horacio E. Camblong

Physics and Astronomy

The interaction of an electron with a polar molecule is shown to be the simplest realization of a quantum anomaly in a physical system. The existence of a critical dipole moment for electron capture and formation of anions, which has been confirmed experimentally and numerically, is derived. This phenomenon is a manifestation of the anomaly associated with quantum symmetry breaking of the classical scale invariance exhibited by the point-dipole interaction. Finally, analysis of symmetry breaking for this system is implemented within two different models: point dipole subject to an anomaly and finite dipole subject to explicit symmetry breaking.

Anomaly Induced Qcd Potential And Quark Decoupling, Joseph Schechter, Stephen D.H. Hsu, Francesco Sannino

Physics - All Scholarship

We explore the anomaly induced effective QCD meson potential in the framework of the effective Lagrangian approach. We suggest a decoupling procedure, when a flavored quark becomes massive, which mimics the one employed by Seiberg for supersymmetric gauge theories. It is seen that, after decoupling, the QCD potential naturally converts to the one with one less flavor. We study the N_c and N_f dependence of the \eta^{\prime} mass.

Energetic Particles And Magnetohydrodynamic Activity In The Swarthmore Spheromak Experiment, G. Qin, Vyacheslav S. Lukin , '00, C. D. Cothran, Michael R. Brown, W. H. Matthaeus

Physics & Astronomy Faculty Works

Results from the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] indicate that formation and partial merging of two spheromak plasmas can be described well by a magnetohydrodynamic (MHD) picture in which there is substantial evolution towards force free states within each vessel, while reconnection activity, also described reasonably well by MHD, occurs in the region of interaction. MHD simulations [V. S. Lukin , Phys. Plasmas 8, 1600 (2001)] support and provide further detail to this interpretation. In the present study, test particle equations are integrated using MHD data from SSX simulations to further understand the …

Design And Construction Of A Space-Borne Optical Tweezer Apparatus, Andrew Resnick

Physics Faculty Publications

A compact optical tweezer package has been developed for use on a microscope to be flown on the International Space Station as part of a series of experiments in colloid crystallization. A brief introduction to the principles of single-beam optical tweezer operation will be presented, after which a detailed system layout will be shown. Special design requirements due to the spaceflight nature of the hardware will also be discussed. The tweezer apparatus is capable of trapping many particles through use of a two-axis acousto-optical deflector. The trap strength is sufficient to perform the required science (50 pN at Δn=0.2). The …

Search For Narrow Diphoton Resonances And For Γγ+W/Z Signatures In Pp̅ Collisions At √S=1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb^-1 of pp̅ collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both pp̅→ γγ+X and pp̅→ γγ+ W/Z. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetrybreaking scale √F in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated …

Electron-Impact Excitation To The 4p⁵5s And 4p⁵5p Levels Of Kr | Using Different Distorted-Wave And Close-Coupling Methods, Arati K. Dasgupta, Klaus Bartschat, D. Vaid, Alexei N. Grum-Grzhimailo, Don H. Madison, Milan Blaha, John L. Giuliani

Physics Faculty Research & Creative Works

Electron-impact excitation of the 4p55s and 4p55p levels of Kr I has been investigated in detail by calculating cross sections using distorted-wave and close-coupling approaches. The results are presented from the excitation thresholds up to 50 eV incident energy. They are contrasted among the different calculations and compared with other theoretical predictions and experimental data. Significant disagreement is found with many of the recent experimental data of Chilton et al. [Phys. Rev. A 62, 032714 (2000)].

Three-Body Coulomb Problem Probed By Mapping The Bethe Surface In Ionizing Ion-Atom Collisions, Robert Moshammer, Appathurai N. Perumal, Michael Schulz, V. D. Rodriguez, Holger Kollmus, Rido Mann, Siegbert Hagmann, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

The three-body Coulomb problem has been explored in kinematically complete experiments on single ionization of helium by 100 MeV / u C 6 + and 3.6 MeV / u u 5 3 + impact. Low-energy electron emission (E e < 150 eV ) as a function of the projectile deflection ϑ p (momentum transfer), i.e., the Bethe surface [[15]], has been mapped with Δ ϑ p ± 25 nanoradian resolution at extremely large perturbations (3.6 MeV / uAu⁵³⁺ ) where single ionization occurs at impact parameters of typically 10 times the He K -shell radius. The experimental data are not in agreement with state-of-the-art continuum distorted wave-eikonal initial state theory.

Multiwavelength Monitoring Of The Narrow-Line Seyfert 1 Galaxy Arakelian 564. Iii. Optical Observations And The Optical--Uv--X-Ray Connection, O. Shemmer, P. Romano, R. Bertram, W. Brinkmann, S. Collier, K. A. Crowley, E. Detsis, A. V. Filippenko, C. Martin Gaskell, T. A. George, M. Gliozzi, M. E. Hiller, T. L. Jewell, Shai Kaspi, Elizabeth S. Klimek, M. H. Lannon, W D. Li, P. Martini, Smita Mathur, H. Negoro, Hagai Netzer, Iossif Papadakis, Ioannis Papamastorakis, Bradley M. Peterson, Bradley W. Peterson, Richard William Pogge, V. I. Pronik, Kenneth S. Rumstay, S. G. Sergeev, G. M. Stirpe, C. J. Taylor, R. R. Treffers, T. J. Turner, P. Uttley, Marianne Vestergaard, Kaspar Von Braun, R. M. Wagner, Z. Zheng

Department of Physics and Astronomy: Faculty Publications

We present the results of a 2 yr long optical monitoring program of the narrow-line Seyfert 1 galaxy Ark 564. The majority of this monitoring project was also covered by X-ray observations (RXT E), and for a period of ~50 days, we observed the galaxy in UV (HST) and X-rays (RXTE and ASCA) simultaneously with the ground-based observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly timescale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (1 day) or long (several months) timescales. The only …

Capillary Flow In Interior Corners: The Infinite Column, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Capillary flow of a sinusoidally perturbed liquid column in an interior corner of infinite extent is solved using lubrication theory. Due primarily to the length scales selected to nondimensionalize the momentum equation, an analytic time scale governing the settling of the perturbation is determined. The time scale, which is shown to be independent of a steady base state flow, proves useful in rapidly predicting transients for surface settling in certain liquid-bearing tanks of spacecraft employing interior corners for fluids management purposes. The asymptotic analysis is extended to address flows along interior corners whose faces are slightly nonplanar. The generalized formulation …

Modeling Axisymmetric Optical Precision Piezoelectric Membranes, James W. Rogers Jr.

Theses and Dissertations

The US Department of Defense (DOD), as well as the National Aeronautics and Astronautics Administration (NASA) and the Jet Propulsion Laboratory (JPL) are interested in developing and deploying precise, compliant, light-weight, space-based structures. More specifically, the Air Force’s core competencies ‘Aerospace Superiority’ and ‘Information Superiority’ demand ever-increasing depth and breadth of capability. Whether used for energy transmission or optical reconnaissance, current launch restraints limit rigid space-based optical reflector size. To support this requirement, the Air Force Research Laboratory (AFRL) is developing a large space-based optical membrane telescope. Inflatable reflectors can conceptually break this barrier, but controlling such a compliant structure …

Investigating The Light Scalar Mesons, Joseph Schechter, D. Black, Amir H. Fariborz, Salah Moussa, S. Nasri

Physics - All Scholarship

We first briefly review a treatment of the scalars in meson meson scattering based on a non-linear chiral Lagrangian, with unitarity implemented by a "local" modification of the scalar propagators. It is shown that the main results are confirmed by a treatment in the SU(3) linear sigma model in which unitarity is implemented "globally". Some remarks are made on the speculative subject of the scalars' quark structure.

The Planetary Nebula A39: An Observational Benchmark For Numerical Modeling Of Photoionized Plasmas, George H. Jacoby, Gary J. Ferland, Kirk T. Korista

Physics and Astronomy Faculty Publications

Galactic nebulae are the main probes for the chemical evolution of the interstellar medium. Yet, recent observations have shown that chemical abundances determined from recombination and collisionally excited emission lines can differ by as much as an order of magnitude in some planetary nebulae (PNs). Many PNs have complex geometries and morphological evidence for interactions from stellar winds, and it is not clear to what extent winds, inhomogeneities, or shocked gas affect the observed spectrum. There currently is no full explanation for this discrepancy, which brings into question whether we understand the physical state of these low-density plasmas at all. …

Temporary Anion States Of Selected Amino Acids, Kayvan Aflatooni, B. Hitt, Gordon A. Gallup, Paul Burrow

Paul Burrow Publications

Vertical attachment energies for the formation of low-lying temporary anion states of glycine, alanine, phenylalanine, tryptophan, and proline in the gas phase are reported using electron transmission spectroscopy. Electron attachment into the empty π* orbital of the –COOH group was observed in all the compounds. Temporary anion states associated with the side groups in phenylalanine and tryptophan are found to be stabilized with respect to those in the reference compounds toluene and indole, respectively, by approximately 0.2 eV. We attribute this to electrostatic effects and explore, using simple theoretical models, the extent to which such anion states could be further …

Search For First-Generation Scalar And Vector Leptoquarks, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We describe a search for the pair production of first-generation scalar and vector leptoquarks in the ee j j and eν jj channels by the DO. Collaboration. The data are from the 1992–1996 pp̅ run at √s =1.8 TeV at the Fermilab Tevatron collider. We find no evidence for leptoquark production; in addition, no kinematically interesting events are observed using relaxed selection criteria. The results from the ee j j and eν jj channels are combined with those from a previous DO. analysis of the νν jj channel to obtain 95% confidence level (C.L.) upper limits on the leptoquark …

Statistics And Supermetallicity: The Metallicity Of Mu Leonis, B. J. Taylor

Faculty Publications

For the often-studied "SMR" giant µ Leo, Smith & Ruck (2000) have recently found that [Fe/H] approximately + 0.3 dex. Their conclusion is tested here in a "statistical" paradigm, in which statistical principles are used to select published high-dispersion µ Leo data and assign error bars to them. When data from Smith & Ruck and from Takeda et al. (1998) are added to a data base compiled in 1999, it is found that conclusions from an earlier analysis (Taylor 1999c) are essentially unchanged: the mean value of [Fe/H] approximately + 0.23 ± 0.025 dex, and values ≤ + 0.2 dex …

Transformation Of Statistics In Fractional Quantum Hall Systems, John J. Quinn, Arkadiusz Wojs, Jennifer J. Quinn, Arthur T. Benjamin

All HMC Faculty Publications and Research

A Fermion to Boson transformation is accomplished by attaching to each Fermion a tube carrying a single quantum of flux oriented opposite to the applied magnetic field. When the mean field approximation is made in Haldane’s spherical geometry, the Fermion angular momentum l_F is replaced by l_B =l_F − 1/2 (N −1). The set of allowed total angular momentum multiplets is identical in the two different pictures. The Fermion and Boson energy spectra in the presence of many body interactions are identical only if the pseudopotential V (interaction energy as a function of pair angular …

Hot Carbon Densities In The Exosphere Of Mars, Andrew F. Nagy, Michael W. Liemohn, Jane L. Fox, Jhoon Kim

Physics Faculty Publications

Theoretical results of hot carbon densities in the exosphere of Mars are presented. The calculation is a two-step process: First a two-stream transport code is used to solve for the distribution function at the exobase, and then these results are used in a Liouville equation solution above the exobase. It is found that photodissociation of carbon monoxide is the largest source of hot carbon atoms in the upper atmosphere of Mars, larger than dissociative recombination of CO⁺ and much larger than the creation of hot carbon through collisions with hot oxygen atoms. It is also found that the high …

Photochemical Escape Of Atomic Carbon From Mars, Jane L. Fox, F. M. Bakalian

Physics Faculty Publications

We have modeled the escape fluxes of atomic carbon from the Martian atmosphere for low and high solar activities due to various photochemical escape mechanisms, including photodissociation of CO, dissociative recombination of CO⁺, electron impact dissociation and dissociative ionization of CO, photodissociative ionization of CO, and dissociative charge transfer of O⁺⁺ to CO. Only photodissociation of CO and dissociative recombination of CO⁺ are found to be important, and the time-averaged escape flux is predicted to be controlled by the high solar activity values. The computed global average escape fluxes of C due to photodissociation of CO …