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J/Psi Production And Suppression In Au+Au Collisions At Sqrt(S_Nn)=200 Gev, Matthew Gerald Wysocki 2010 University of Colorado at Boulder

J/Psi Production And Suppression In Au+Au Collisions At Sqrt(S_Nn)=200 Gev, Matthew Gerald Wysocki

Physics Graduate Theses & Dissertations

In high-energy heavy ion collisions a partonic state of matter known as the quark-gluon plasma is expected to be formed. The suppression of J/psi meson production in high-energy heavy ion collisions is expected to be a strong signature for the formation of the quark-gluon plasma, due to Debye screening of the quark-antiquark potential. To investigate the state of matter produced in Au+Au collisions at sqrt(sNN)=200 GeV at the PHENIX experiment, we have analyzed forward rapidity J/psi [arrow] μ+μ- production and find that J/psi production is significantly suppressed in collisions at small impact ...


Cold Polar Molecules For Novel Collision Experiments At Low Energies, Brian Sawyer 2010 University of Colorado, Boulder

Cold Polar Molecules For Novel Collision Experiments At Low Energies, Brian Sawyer

Physics Graduate Theses & Dissertations

Research in the field of cold polar molecules is progressing rapidly. An array of interesting

topics is being developed including precision measurement and fundamental tests, quantum phase transitions, and ultracold chemistry. In particular, dipolar molecules in well-defined quantum states enable exquisite control of their interactions via applied electric fields. The long-range, anisotropic interaction between dipolar molecules leads to new collision dynamics that could be used for novel collective effects, quantum state engineering, and information processing. The focus of this Thesis is the production of cold samples of neutral OH molecules via Stark deceleration and magnetic trapping for novel collision experiments ...


Control Of Dipolar Collisions In The Quantum Regime, Marcio H.G. Miranda 2010 University of Colorado, Boulder

Control Of Dipolar Collisions In The Quantum Regime, Marcio H.G. Miranda

Physics Graduate Theses & Dissertations

The preparation of ultracold polar molecular gases close to quantum degeneracy opens novel research prospects ranging from dipolar quantum many-body physics to ultracold chemistry. With a near quantum degenerate gas of fermionic 40K87Rb polar molecules, this thesis presents studies on dipolar collision and chemical reaction dynamics, exhibiting long range interactions and spatial anisotropy. With full control over the internal quantum state of the molecules, we show how quantum statistics of the molecule determines the rate of chemical reactivity in the limit of vanishing collisional energy. Manipulating the interaction potential between indistinguishable polar molecules by means of control ...


Electric-Field Affected Low-Energy Collisions Between Co-Trapped Ammonia And Rubidium, Lambert Paul Parazzoli 2010 University of Colorado at Boulder

Electric-Field Affected Low-Energy Collisions Between Co-Trapped Ammonia And Rubidium, Lambert Paul Parazzoli

Physics Graduate Theses & Dissertations

This thesis describes the effect of an electric field on the interaction between rubidium and ammonia at 100 mK. The ability to study low energy interactions between molecules and atoms provides new tools to understand how the processes that govern these interactions work. For example, the use of external electric and magnetic fields provides tools to spatially orient molecules to show how this affects the dynamics of the interaction. The use of electric fields have been proposed to affect dipole-dipole interactions, however we have showed that the space-orienting effect of the field can have a significant effect even in the ...


Probing An Interacting Bose Gas In A Quasi-Two-Dimensional Trap, Shihkuang Tung 2010 University of Colorado, Boulder

Probing An Interacting Bose Gas In A Quasi-Two-Dimensional Trap, Shihkuang Tung

Physics Graduate Theses & Dissertations

A fluctuating regime associated with the Berenzinskii-Kosterlitz-Thouless (BKT) transition is studied in a two-dimensional system of near-degenerate bosons (87Rb atoms). Two imaging procedures, the in-situ imaging method and the focusing-imaging method, are implemented to image the coordinate-space and momentum-space density distributions. The scaled compressibility is extracted from the coordinate-space density distributions obtained from in-situ images. Comparing the measured compressibility to the prediction from our semiclassical mean-field model, an onset of a regime which is beyond the mean-field prediction is identified and first resolved at phase-space density 2 ≥ 3. Information about the coherence of the system is extracted from ...


Towards Measuring The Electron Electric Dipole Moment Using Trapped Molecular Ions, Russell Stutz 2010 University of Colorado, Boulder

Towards Measuring The Electron Electric Dipole Moment Using Trapped Molecular Ions, Russell Stutz

Physics Graduate Theses & Dissertations

Permanent electric dipole moments have been the subject of experimental investigation for the past sixty years, as they entail the breaking of fundamental symmetries and provide a sensitive probe for physics beyond the Standard Model. This thesis describes an experiment aimed at measuring the electron electric dipole moment (eEDM) using trapped molecular ions. The 3Δ1 level of certain diatomic ions are desirable in eEDM searches due to their high polarizability, large eEDM enhancement factor, and relative insensitivity to magnetic fields. Ions allow for simple trapping and long interrogation times, but require a time-varying electric bias field in order ...


Two-Species Ion Arrays For Quantum Logic Spectroscopy And Entanglement Generation, David Brian Hume 2010 University of Colorado, Boulder

Two-Species Ion Arrays For Quantum Logic Spectroscopy And Entanglement Generation, David Brian Hume

Physics Graduate Theses & Dissertations

The quantum states of trapped atomic ions can be highly isolated from external perturbation, and precisely manipulated with applied laser fields. This makes them an excellent medium for quantum-limited experiments such as quantum information processing and precision spectroscopy. A relatively small number of ion species have been used for these types of experiments because most species are difficult to laser cool and detect directly. This thesis demonstrates a way to overcome this limitation by use of sympathetic cooling and state detection based on quantum logic. We apply these techniques to mixed-species arrays of Al+ and Be+ ions. A mathematical model ...


Aging To Equilibrium Dynamics Of Sio2, Katharina Vollmayr-Lee, J. A. Roman, J. Horbach 2010 Bucknell University

Aging To Equilibrium Dynamics Of Sio2, Katharina Vollmayr-Lee, J. A. Roman, J. Horbach

Faculty Journal Articles

No abstract provided.


Probing Equilibrium By Nonequilibrium Dynamics: Aging In Co/Cr Superlattices, Tathagata Mukherjee, M. Pleimling, Christian Binek 2010 University of Nebraska–Lincoln

Probing Equilibrium By Nonequilibrium Dynamics: Aging In Co/Cr Superlattices, Tathagata Mukherjee, M. Pleimling, Christian Binek

Christian Binek Publications

Magnetization relaxation is investigated in a structurally ordered magnetic Co/Cr superlattice. Tailored nanoscale periodicity creates mesoscopic spatial magnetic correlations with slow relaxation dynamics when quenching the system into a nonequilibrium state. Magnetization transients are measured after exposing the heterostructure to a magnetic set field for various waiting times. Scaling analysis reveals an asymptotic powerlaw behavior in accordance with a full aging scenario. The temperature dependence of the relaxation exponent shows pronounced anomalies at the equilibrium phase transitions of the antiferromagnetic superstructure and the ferromagnetic to paramagnetic transition of the Co layers. The latter leaves only weak fingerprints in the ...


Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur 2010 University of Kentucky

Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur

University of Kentucky Doctoral Dissertations

This dissertation focuses on near-field radiative transfer, which can be defined as the discipline concerned with energy transfer via electromagnetic waves at sub-wavelength distances. Three specific subjects related to this discipline are investigated, namely nearfield thermal radiation, nanoscale-gap thermophotovoltaic (nano-TPV) power generation and optical characterization. An algorithm for the solution of near-field thermal radiation problems in one-dimensional layered media is developed, and several tests are performed showing the accuracy, consistency and versatility of the procedure. The possibility of tuning near-field radiative heat transfer via thin films supporting surface phononpolaritons (SPhPs) in the infrared is afterwards investigated via the computation of ...


Measurement Of Single-Target Spin Asymmetries In The Electroproduction Of Negative Pions In The Semi-Inclusive Deep Inelastic Reaction N↑(E,Éπ¯)X On A Transversely Polarized 3he Target, Chiranjib Dutta 2010 University of Kentucky

Measurement Of Single-Target Spin Asymmetries In The Electroproduction Of Negative Pions In The Semi-Inclusive Deep Inelastic Reaction N↑(E,Éπ¯)X On A Transversely Polarized 3he Target, Chiranjib Dutta

University of Kentucky Doctoral Dissertations

The experiment E06010 measured the target single spin asymmetry (SSA) in the semiinclusive deep inelastic (SIDIS) n↑(e,éπ¯)X reaction with a transversely polarized 3He target as an effective neutron target. This is the very first independent measurement of the neutron SSA, following the measurements at HERMES and COMPASS on the proton and the deuteron. The experiment acquired data in Hall A at Jefferson Laboratory with a continuous electron beam of energy 5.9 GeV, probing the valence quark region, with x = 0.13→0.41, at Q2 = 1.31→3.1 GeV2. The two contributing ...


Tunneling Spectroscopy Study Of Calcium Ruthenate, Anthony Bautista 2010 University of Kentucky

Tunneling Spectroscopy Study Of Calcium Ruthenate, Anthony Bautista

University of Kentucky Doctoral Dissertations

The ruthenates are perhaps one of the most diverse group of materials known up to date. These compounds exhibit a wide array of behaviors ranging from the exotic pwave superconductivity in Sr2RuO4, to the itinerant ferromagnetism in SrRuO3, and the Mott-insulating behavior in Ca2RuO4. One of the most intriguing compounds belonging to this group is Ca3Ru2O7 which is known to undergo an antiferromagnetic ordering at 56K and an insulating transition at 48K. Most intriguing, however, is the behavior displayed by this compound in the presence of an external ...


A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving 2010 Technological University Dublin

A Phenomenographic Study Of Introductory Physics Students: Approaches To Their Learning And Perceptions Of Their Learning Environment In A Physics Problem-Based Learning Environment, Paul Irving

Doctoral

This phenomenographic study describes students’ approaches to learning and their perceptions of the learning environment in an introductory physics course which is taught using a problem-based learning approach. This research builds on previous studies which showed that these students develop a greater conceptual knowledge than their counterparts in a more traditional learning environment while others showed very little development even though they engaged fully with the pedagogy. This study aimed to examine and describe the students’ approaches to learning. The definitions of surface, strategic and deep approaches to learning are not appropriate in this context and could not be applied ...


Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite 2010 Technological University Dublin

Photopolymerizable Nanocomposites For Holographic Applications, Elsa Leite

Doctoral

Photopolymerizable nanocomposites with good optical properties consisting of an acrylamide based photopolymer and zeolite nanoparticles (Beta, zeolite A, AlPO-18, silicalite-1 and zeolite L) were fabricated and characterized for holographic applications. The colloidal zeolite solutions used in this project were characterized by several techniques including X-Ray Diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Raman spectroscopy to ensure their successful synthesis. The dependence of grating performances in these nanocomposites on recording intensity, spatial frequency and zeolite concentration were studied. It was found that the incorporation of silicalite-1 nanoparticles or a small amount of zeolite A nanoparticles (up to ...


The Beliaev Technique For A Weakly Interacting Bose Gas, B Capogrosso-Sansone, S Giorgini, S Pilati, L. Pollet, N Prokof'ev, B Svistunov, M Troyer 2010 University of Massachusetts - Amherst

The Beliaev Technique For A Weakly Interacting Bose Gas, B Capogrosso-Sansone, S Giorgini, S Pilati, L. Pollet, N Prokof'ev, B Svistunov, M Troyer

Physics Department Faculty Publication Series

Aiming at simplicity of explicit equations and, at the same time, controllable accuracy of the theory, we present our results for all the thermodynamic quantities and correlation functions for a weakly interacting Bose gas at short-to-intermediate distances obtained within an improved version of Beliaev's diagrammatic technique. With a controllably small (but essentially finite) Bogoliubov's symmetry-breaking term, Beliaev's diagrammatic technique becomes regular in the infrared limit. Up to higher-order terms (for which we present parametric order-of-magnitude estimates), the partition function and entropy of the system formally correspond to those of a non-interacting bosonic (pseudo-)Hamiltonian with a temperature-dependent ...


Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight 2010 University of Massachusetts - Amherst

Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight

Physics Department Faculty Publication Series

We show that in multiband superconductors, even an extremely small interband proximity effect can lead to a qualitative change in the interaction potential between superconducting vortices by producing long-range intervortex attraction. This type of vortex interaction results in an unusual response to low magnetic fields leading to phase separation into domains of two-component Meissner states and vortex droplets.


Beyond Spontaneously Broken Symmetry In Bose-Einstein Condensates, WJ Mullin, F Laloe 2010 University of Massachusetts - Amherst

Beyond Spontaneously Broken Symmetry In Bose-Einstein Condensates, Wj Mullin, F Laloe

Physics Department Faculty Publication Series

Spontaneous symmetry breaking (SSB) for Bose-Einstein condensates cannot treat phase off-diagonal effects, and thus cannot explain Bell inequality violations. We describe another situation that is beyond a SSB treatment: an experiment where particles from two (possibly macroscopic) condensate sources are used for conjugate measurements of the relative phase and populations. Off-diagonal phase effects are characterized by a “quantum angle” and observed via “population oscillations,” signaling quantum interference of macroscopically distinct states.


Classical Phases And Quantum Angles In The Description Of Interfering Bose-Einstein Condensates, WJ Mullin, F Laloe 2010 University of Massachusetts - Amherst

Classical Phases And Quantum Angles In The Description Of Interfering Bose-Einstein Condensates, Wj Mullin, F Laloe

Physics Department Faculty Publication Series

The interference of two Bose-Einstein condensates, initially in Fock states, can be described in terms of their relative phase, treated as a random unknown variable. This phase can be understood either as emerging from the measurements or pre-existing to them; in the latter case, the originating states could be phase states with unknown phases, so an average over all their possible values is taken. Both points of view lead to a description of probabilities of results of experiments in terms of a phase angle, which plays the role of a classical variable. Nevertheless, in some situations, this description is not ...


Regge Kinematics In Soft Collinear Effective Theory, JF Donoghue, D Wyler 2010 University of Massachusetts Amherst

Regge Kinematics In Soft Collinear Effective Theory, Jf Donoghue, D Wyler

Physics Department Faculty Publication Series

We discuss the kinematics of the particles that make up a Reggeon in field theory, using the terminology of the soft collinear effective theory (SCET). Reggeization sums a series of strongly ordered collinear emissions resulting in an overall Reggeon exchange that falls in the Glauber or Coulomb kinematic region. This is an extremely multiscale problem and appears to fall outside of the usual organizing scheme of SCET.


Towards The Clinical Application Of Laser-Induced Breakdown Spectroscopy For Rapid Pathogen Diagnosis: The Effect Of Mixed Cultures And Sample Dilution On Bacterial Identification, Steven J. Rehse, Q.I. Mohaidat, S. Palchaudhuri 2010 University of Windsor

Towards The Clinical Application Of Laser-Induced Breakdown Spectroscopy For Rapid Pathogen Diagnosis: The Effect Of Mixed Cultures And Sample Dilution On Bacterial Identification, Steven J. Rehse, Q.I. Mohaidat, S. Palchaudhuri

Physics Publications

Laser-induced breakdown spectroscopy has been utilized to classify and identify bacterial specimens on the basis of their atomic composition. We have characterized the effect that the presence of a second bacterial species in the ablated specimen had on the identification of the majority species. Specimens with a reduced number of bacterial cells (approximately 2500) were identified with 100% accuracy when compared to undiluted specimens. In addition, a linear dependence of the total spectral power as a function of cell number was determined. Lastly, a high selectivity was obtained for a LIBS-based analysis of nine separate bacterial strains from four genera.


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