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Photo-Induced Current Measurements In Chlamydomonas Cell Suspensions, Collin D. Capano May 2005

Photo-Induced Current Measurements In Chlamydomonas Cell Suspensions, Collin D. Capano

Renée Crown University Honors Thesis Projects - All

In order to fully understand the principles behind phototaxis in flagellate algae, it is necessary to measure the electric currents these cells create when processing light stimuli. Many different techniques have been developed to do this. One of these techniques, measuring from cell suspensions, has a number of advantages over the others that makes it highly desirable. However, the lab that first developed this method of recording did not describe the setup very well. The result is that in the thirteen years since it was first reported, only one other independent lab has been able to reproduce the results despite …

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Evidence For A Weak Galactic Center Magnetic Field From Diffuse Low Frequency Nonthermal Radio Emission, Ted N. Larosa, C. L. Brogan, S. N. Shore, T. J. Lazio, N. E. Kassim, M. E. Nord May 2005

Evidence For A Weak Galactic Center Magnetic Field From Diffuse Low Frequency Nonthermal Radio Emission, Ted N. Larosa, C. L. Brogan, S. N. Shore, T. J. Lazio, N. E. Kassim, M. E. Nord

Faculty Articles

New low-frequency 74 and 330 MHz observations of the Galactic center (GC) region reveal the presence of a large-scale (6° × 2°) diffuse source of nonthermal synchrotron emission. A minimum-energy analysis of this emission yields a total energy of ~(4/7f3/7) × 1052 ergs and a magnetic field strength of ~6(/f)2/7 μG (where is the proton to electron energy ratio and f is the filling factor of the synchrotron emitting gas). The equipartition particle energy density is 1.2(/f)2/7 eV cm-3, a value consistent with cosmic-ray data. However, the derived magnetic field is several orders of …

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Analysis And Interpretation Of Total Electron Content Measurements, Geonhwa Jee May 2005

Analysis And Interpretation Of Total Electron Content Measurements, Geonhwa Jee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

TEC data from nearly 10 years of the TOPEX/Poseidon mission were analyzed to study the TEC climatology. First, the TEC data were binned by season, geomagnetic activity, and solar activity to create longitudinally averaged TEC maps in magnetic latitude and local time. The equatorial anomaly is the most prominent feature in these maps and they show strong TEC variations with solar activity but relatively weak variations with geomagnetic activity in our three Kp bins. These maps also show the annual and semiannual anomalies, but lack the seasonal anomaly. As a final binning, three longitudinal bins (Indian, Pacific, and Atlantic) were …

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Charged Higgs Production Via Bg -> Th(-) At The Lhc, Nikolaos Kidonakis May 2005

Charged Higgs Production Via Bg -> Th(-) At The Lhc, Nikolaos Kidonakis

Faculty Articles

I present a calculation of QCD radiative corrections to charged Higgs production via the process bg -> tH-. I show that the cross section is dominated by soft-gluon corrections, which are computed through next-to-next-to-leading order. Results for charged Higgs production at the LHC are presented, including the dependence of the cross section on the charged Higgs mass, the top quark mass, the factorization and renormalization scales, and tan beta.

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Measurements Of The Secondary Electron Emission Properties Of Insulators, Clint D. Thomson May 2005

Measurements Of The Secondary Electron Emission Properties Of Insulators, Clint D. Thomson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measurements of the electron-induced electron emission properties of insulators are important to many applications including spacecraft charging, scanning electron microscopy, electron sources, and particle detection technology. However, these measurements are difficult to make since insulators can charge either negatively or positively under charge particle bombardment that in turn alters insulator emissions. In addition, incident electron bombardment can modify the conductivity, internal charge distribution, surface potential, and material structure in ways that are not well understood. A primary goal of this dissertation work has been to make consistent and accurate measurements of the uncharged electron yields for insulator materials using innovative …

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Measurement Of The Ratio Of Inclusive Cross Sections Σ(Pp̅ → Z + B Jet)/Σ(Pp̅ → Z + Jet) At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration Apr 2005

Measurement Of The Ratio Of Inclusive Cross Sections Σ(Pp̅ → Z + B Jet)/Σ(Pp̅ → Z + Jet) At √S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

Using the data collected with the D0 detector at √s = 1.96 TeV, for integrated luminosities of about 180 pb-1, we have measured the ratio of inclusive cross sections for pp̅ → Z + b jet to pp̅ → Z + jet production. The inclusive Z + b-jet reaction is an important background to searches for the Higgs boson in associated ZH production at the Fermilab Tevatron collider. Our measurement is the first of its kind, and relies on the Z → ℯ+ℯ- and Z → μ+μ- modes. The combined …

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Pion Interferometry In Au+Au Collisions At √SNn = 200 Gev, Star Collaboration, T.D. Gutierrez Apr 2005

Pion Interferometry In Au+Au Collisions At √SNn = 200 Gev, Star Collaboration, T.D. Gutierrez

Physics

We present a systematic analysis of two-pion interferometry in Au+Au collisions at √sNN=200GeV using the STAR detector at Relativistic Heavy Ion Collider. We extract the Hanbury-Brown and Twiss radii and study their multiplicity, transverse momentum, and azimuthal angle dependence. The Gaussianness of the correlation function is studied. Estimates of the geometrical and dynamical structure of the freeze-out source are extracted by fits with blast-wave parametrizations. The expansion of the source and its relation with the initial energy density distribution is studied.

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Search For First-Generation Scalar Leptoquarks In (Pp̅ Collisions At√S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration Apr 2005

Search For First-Generation Scalar Leptoquarks In (Pp̅ Collisions At√S = 1.96 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We report on a search for pair production of first-generation scalar leptoquarks (LQ) in pp̅ collisions at √s = 1.96 TeV using an integrated luminosity of 252 pb-1 collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQL̅Q̅ → ℯqℯq and LQL̅Q̅ → ℯqνq, and derive 95% C.L. lower limits on the LQ mass as a function of β, where β is the branching fraction for LQ → ℯq. The limits are 241 and 218 GeV/c2 for β = 1 and …

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Formation Of Molecular Hydrogen On Analogues Of Interstellar Dust Grains: Experiments And Modelling, Gianfranco Vidali, Joe Roser Apr 2005

Formation Of Molecular Hydrogen On Analogues Of Interstellar Dust Grains: Experiments And Modelling, Gianfranco Vidali, Joe Roser

Physics - All Scholarship

Molecular hydrogen has an important role in the early stages of star formation as well as in the production of many other molecules that have been detected in the interstellar medium. In this review we show that it is now possible to study the formation of molecular hydrogen in simulated astrophysical environments. Since the formation of molecular hydrogen is believed to take place on dust grains, we show that surface science techniques such as thermal desorption and time-of-flight can be used to measure the recombination efficiency, the kinetics of reaction and the dynamics of desorption. The analysis of the experimental …

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Search For Anomalous Heavy-Flavor Quark Production In Association With W Bosons, V. M. Abazov, Gregory R. Snow, D0 Collaboration Apr 2005

Search For Anomalous Heavy-Flavor Quark Production In Association With W Bosons, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We search for anomalous production of heavy-flavor quark jets in association with W bosons at the Fermilab Tevatron pp̅ Collider in final states in which the heavy-flavor quark content is enhanced by requiring at least one tagged jet in an event. Jets are tagged using one algorithm based on semileptonic decays of b/c hadrons, and another on their lifetimes. We compare ℯ+ jets (164 pb-1) and μ+ jets (145 pb-1) channels collected with the D0 detector at √s = 1.96 TeV to expectations from the standard model and set upper limits …

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Numerical Solutions Of The Three-Dimensional Magnetohydrodynamic Α Model, Pablo D. Mininni, David C. Montgomery, Annick Pouquet Apr 2005

Numerical Solutions Of The Three-Dimensional Magnetohydrodynamic Α Model, Pablo D. Mininni, David C. Montgomery, Annick Pouquet

Dartmouth Scholarship

We present direct numerical simulations and α-model simulations of four familiar three-dimensional magnetohydrodynamic (MHD) turbulence effects: selective decay, dynamic alignment, inverse cascade of magnetic helicity, and the helical dynamo effect. The MHD α model is shown to capture the long-wavelength spectra in all these problems, allowing for a significant reduction of computer time and memory at the same kinetic and magnetic Reynolds numbers. In the helical dynamo, not only does the α model correctly reproduce the growth rate of magnetic energy during the kinematic regime, it also captures the nonlinear saturation level and the late generation of a large scale …

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Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S =1.96 Tev Using Kinematic Fitting Of B-Tagged Lepton+Jet Events, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Apr 2005

Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S =1.96 Tev Using Kinematic Fitting Of B-Tagged Lepton+Jet Events, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report a measurement of the tt̅ production cross section using the CDF II detector at the Fermilab Tevatron. The data consist of events with an energetic electron or muon, missing transverse energy, and three or more hadronic jets, at least one of which is identified as a b-quark jet by reconstructing a secondary vertex. The background fraction is determined from a fit of the transverse energy of the leading jet. Using 162±10 pb-1 of data, the total cross section is found to be 6.0±1.6(stat.)±1.2(syst.) pb, which is consistent with the standard model prediction.

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Energy Levels And Transition Probabilities For Nitrogen-Like Fe Xx, V. Jonauskas, P. Bogdanovich, F. P. Keenan, M. E. Foord, R. F. Heeter, S. J. Rose, Gary J. Ferland, R. Kisielius, Peter A. M. Van Hoof, P. H. Norrington Apr 2005

Energy Levels And Transition Probabilities For Nitrogen-Like Fe Xx, V. Jonauskas, P. Bogdanovich, F. P. Keenan, M. E. Foord, R. F. Heeter, S. J. Rose, Gary J. Ferland, R. Kisielius, Peter A. M. Van Hoof, P. H. Norrington

Physics and Astronomy Faculty Publications

Energies of the 700 lowest levels in Fexx have been obtained using the multiconfiguration Dirac-Fock method. Configuration interaction method on the basis set of transformed radial orbitals with variable parameters taking into account relativistic corrections in the Breit-Pauli approximation was used to crosscheck our presented results. Transition probabilities, oscillator and line strengths are presented for electric dipole (E1), electric quadrupole (E2) and magnetic dipole (M1) transitions among these levels. The total radiative transition probabilities from each level are also provided. Results are compared with data compiled by NIST and with other theoretical work.

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High-Temperature Ferromagnetism In Pulsed-Laser Deposited Epitaxial (Zn,Mn)O Thin Films: Effects Of Substrate Temperature, Aswini K. Pradhan, Kai Zhang, S. Mohanty, J.B. Dadson, D. Hunter, Jun Zhang, David J. Sellmyer, U.N. Roy, Y. Cui, A. Burger, S. Mathews, B. Joseph, B.R. Sekhar, B.K. Roul Apr 2005

High-Temperature Ferromagnetism In Pulsed-Laser Deposited Epitaxial (Zn,Mn)O Thin Films: Effects Of Substrate Temperature, Aswini K. Pradhan, Kai Zhang, S. Mohanty, J.B. Dadson, D. Hunter, Jun Zhang, David J. Sellmyer, U.N. Roy, Y. Cui, A. Burger, S. Mathews, B. Joseph, B.R. Sekhar, B.K. Roul

David Sellmyer Publications

We report on the observation of remarkable room-temperature ferromagnetism in epitaxial (Zn,Mn)O films grown by a pulsed-laser deposition technique using high-density targets. The optimum growth conditions were demonstrated from x-ray measurements, microstructure, Rutherford backscattering, micro-Raman, and magnetic studies. Superior ferromagnetic properties were observed in (Zn,Mn)O films grown at a substrate temperature of 500 °C and with an oxygen partial pressure of 1 mTorr. Ferromagnetism becomes weaker with increasing substrate temperature due to the formation of isolated Mn clusters irrespective of higher crystalline quality of the film.

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X-Ray/Ultraviolet Observing Campaign Of The Markarian 279 Active Galactic Nucleus Outflow: A Global-Fitting Analysis Of The Ultraviolet Absorption, Jack R. Gabel, Nahum Arav, Jelle S. Kaastra, Gerard A. Kriss, Ehud Behar, Elisa Costantini, C. Martin Gaskell, Kirk T. Korista, Ari Laor, Frits Paerels, Daniel Proga, Jessica Kim-Quijano, Masao Sako, Jennifer E. Scott, Katrien C. Steenbrugge Apr 2005

X-Ray/Ultraviolet Observing Campaign Of The Markarian 279 Active Galactic Nucleus Outflow: A Global-Fitting Analysis Of The Ultraviolet Absorption, Jack R. Gabel, Nahum Arav, Jelle S. Kaastra, Gerard A. Kriss, Ehud Behar, Elisa Costantini, C. Martin Gaskell, Kirk T. Korista, Ari Laor, Frits Paerels, Daniel Proga, Jessica Kim-Quijano, Masao Sako, Jennifer E. Scott, Katrien C. Steenbrugge

Department of Physics and Astronomy: Faculty Publications

We present an analysis of the intrinsic UVabsorption in the Seyfert 1 galaxy Mrk 279 based on simultaneous long observations with the Hubble Space Telescope (41 ks) and the Far Ultraviolet Spectroscopic Explorer (91 ks). To extract the line-of-sight covering factors and ionic column densities, we separately fit two groups of absorption lines: the Lyman series and the CNO lithium-like doublets. For the CNO doublets we assume that all three ions share the same covering factors. The fitting method applied here overcomes some limitations of the traditional method using individual doublet pairs; it allows for the treatment ofmore complex, physically …

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Weak Point Disorder In Strongly Fluctuating Flux-Line Liquids, Panayotis Benetatos, M. Cristina Marchetti Apr 2005

Weak Point Disorder In Strongly Fluctuating Flux-Line Liquids, Panayotis Benetatos, M. Cristina Marchetti

Physics - All Scholarship

We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2+1 dimensions [P. Benetatos and M. C. Marchetti, Phys. Rev. B 64, 054518, (2001)]. In this model, flux lines are allowed to be arbitrarily curved and can even form closed loops. Point defects can be scalar or polar. In the latter case, the direction of their dipole moments can be random or correlated. Within the Gaussian approximation of our hydrodynamic model, …

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Measurement Of Σ(Pp̅→Z)•Br(Z→ Ττ) At √S = 1.96tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration Apr 2005

Measurement Of Σ(Pp̅→Z)•Br(Z→ Ττ) At √S = 1.96tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We present a measurement of the cross section for Z production times the branching fraction to _ leptons, σ•Br(Z → τ+τ-), in pp̅ collisions at √s = 1.96 TeV in the channel in which one τ decays into μνμντ, and the other into hadrons +ντ or ℯνℯντ. The data sample corresponds to an integrated luminosity of 226 pb-1 collected with the D0 detector at the Fermilab Tevatron collider. The final sample contains 2008 candidate events with an estimated background of 55%. From this we …

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Rotationally Induced Penning Ionization Of Ultracold Photoassociated Helium Dimers, J. Léonard, A. P. Mosk, M. Walhout, M. Leduc Apr 2005

Rotationally Induced Penning Ionization Of Ultracold Photoassociated Helium Dimers, J. Léonard, A. P. Mosk, M. Walhout, M. Leduc

University Faculty Publications and Creative Works

We have studied photoassociation of metastable 23S1 helium atoms near the 23S1-23P2 asymptote by both ion detection in a magneto-optical trap and trap-loss measurements in a magnetic trap. A detailed comparison between the results of the two experiments gives insight into the mechanism of the Penning ionization process. We have identified four series of resonances corresponding to vibrational molecular levels belonging to different rotational states in two potentials. The corresponding spin states become quasi-purely quintet at small interatomic distance, and Penning ionization is inhibited by spin conservation rules. Only a weak rotational coupling is responsible for the contamination by singlet …

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Spectroscopic Studies On Cobalt(Ii)-Substituted Metallo-Β-Lactamase Imis From Aeromonas Veronii Bv. Sobria, Patrick A. Crawford, Ke-Wu Yang, Narayan Sharma, Brian Bennett, Michael W. Crowder Apr 2005

Spectroscopic Studies On Cobalt(Ii)-Substituted Metallo-Β-Lactamase Imis From Aeromonas Veronii Bv. Sobria, Patrick A. Crawford, Ke-Wu Yang, Narayan Sharma, Brian Bennett, Michael W. Crowder

Physics Faculty Research and Publications

In an effort to probe the structure of a group Bb metallo-β-lactamase, Co(II)-substituted ImiS was prepared and characterized by electronic absorption, NMR, and EPR spectroscopies. ImiS containing 1 equiv of Co(II) (Co(II)1-ImiS) was shown to be catalytically active. Electronic absorption studies of Co(II)1-ImiS revealed the presence of two distinct features:  (1) an intense sulfur to Co(II) ligand to metal charge transfer band and (2) less intense, Co(II) ligand field transitions that suggest 4-coordinate Co(II) in Co(II)1-ImiS. 1H NMR studies of Co(II)1-ImiS suggest that one histidine, one aspartic acid, and one cysteine …

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Measurement Of Partial Widths And Search For Direct Cp Violation, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Apr 2005

Measurement Of Partial Widths And Search For Direct Cp Violation, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of relative partial widths and decay rate CP asymmetries in K-K+ and π- π+ decays of D0 mesons produced in pp̅ collisions at √s=1.96 TeV. We use a sample of 2×105 D*+ D0 π+ (and charge conjugate) decays with the D0 decaying to K- π +, K-K+, and π- π+, corresponding to 123 pb-1 of data collected by the Collider Detector at Fermilab II experiment at the Fermilab Tevatron collider. No significant direct CP violation is …

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Photometry Of Outer-Belt Objects, Gautham S. Narayan '05 Apr 2005

Photometry Of Outer-Belt Objects, Gautham S. Narayan '05

Honors Projects

We present results from multi-wavelength observations of outer-belt asteroid 279 Thule and comet C12002 CE10 (LINEAR). The orbital elements of the second object, formerly classified as asteroid 2002 CE10, at first led to its identification with a group of asteroids called the Damocloids. The Damocloids' orbits are similar to Halley family comets (HFCs), and there is suspicion that the Damocloids are inactive HFC nuclei. Following observations by the 8.2 m Japanese Subaru telescope in August 2003, which determined that 2002 CE IO had a characteristic tail (Takato et al; 2003), it was re-classified as comet C/2002 CE10 (LINEAR). We observed …

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Photometry Of Type Ii Cepheids. Ii. The Short-Period Stars, Edward G. Schmidt, Dale Johnston, Shawn Langan, Kevin M. Lee Apr 2005

Photometry Of Type Ii Cepheids. Ii. The Short-Period Stars, Edward G. Schmidt, Dale Johnston, Shawn Langan, Kevin M. Lee

Department of Physics and Astronomy: Faculty Publications

We present 668 new photometric observations for 24 Cepheids with periods less than 3 days. Most of the stars are probable type II Cepheids, but we have included some type I Cepheids for comparison. A discussion of the Fourier parameters of the light curves leads to the conclusion that they can be used to distinguish among the several types of light curves found among the type II stars but are of limited usefulness for distinguishing between type I and type II Cepheids. The pulsational stability is investigated by searching for long-term changes in the light-curve shapes, period changes, and light-curve …

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The Straggling Green's Function Method For Ion Transport, Steven Andrew Walker Apr 2005

The Straggling Green's Function Method For Ion Transport, Steven Andrew Walker

Mathematics & Statistics Theses & Dissertations

For many years work has been conducted on developing a concise theory and method for HZE ion transport capable of being validated in the laboratory. Previous attempts have ignored dispersion and energy downshift associated with nuclear fragmentation and energy and range straggling. Here we present a Green's function approach to ion transport that incorporates these missing elements. This work forms the basis for a new version of GRNTRN, a Green's function transport code. Comparisons of GRNTRN predictions and laboratory results for an 56Fe ion beam with average energy at the target of one GeV/amu or more are presented for …

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Measurement Of The Forward-Backward Charge Asymmetry From W→Eν Production In Pp̅ Collisions At √S=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 2005

Measurement Of The Forward-Backward Charge Asymmetry From W→Eν Production In Pp̅ Collisions At √S=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in pp̅ collisions at √s =1.96 TeV using a data sample of 170 pb-1 collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the U and d quark parton distribution functions within the proton.

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Optimal Reconstruction Of Magnetopause Structures From Cluster Data, H Hasegawa, B U. Ö Sonnerup, B Klecker, G Paschmann Mar 2005

Optimal Reconstruction Of Magnetopause Structures From Cluster Data, H Hasegawa, B U. Ö Sonnerup, B Klecker, G Paschmann

Dartmouth Scholarship

The Grad-Shafranov (GS) reconstruction tech- nique, a single-spacecraft based data analysis method for recovering approximately two-dimensional (2-D) magneto- hydrostatic plasma/field structures in space, is improved to become a multi-spacecraft technique that produces a single field map by ingesting data from all four Cluster spacecraft into the calculation. The plasma pressure, required for the technique, is measured in high time resolution by only two of the spacecraft, C1 and C3, but, with the help of spacecraft po- tential measurements available from all four spacecraft, the pressure can be estimated at the other spacecraft as well via a relationship, established from C1 …

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Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S=1.96 Tev Using Lepton + Jets Events With Secondary Vertex B -Tagging, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 2005

Measurement Of The Tt̅ Production Cross Section In Pp̅ Collisions At √S=1.96 Tev Using Lepton + Jets Events With Secondary Vertex B -Tagging, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the tt̅ production cross section using events with one charged lepton and jets from pp̅ collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb-1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5±1.8 events are expected from background contributions. We measure a tt̅ production cross section of 5.6-1.1+1.2 (stat.) -0.6+0.9 (syst.) pb.

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Measurement Of The Forward-Backward Charge Asymmetry Of Electron-Positron Pairs In Pp̅ Collisions At Sqrt(S)=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 2005

Measurement Of The Forward-Backward Charge Asymmetry Of Electron-Positron Pairs In Pp̅ Collisions At Sqrt(S)=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the mass dependence of the forward-backward charge asymmetry (AFB) for e+e- pairs produced via an intermediate Z/ γ * with mass Mee>40 GeV/c2. We study the constraints on the Z-quark couplings imposed by our measurement. We analyze an integrated luminosity of 72 pb-1 collected by the CDF-II detector in pp̅ collisions at √s =1.96 TeV at the Fermilab Tevatron. A comparison of the uncorrected AFB between data and standard model Monte Carlo gives good agreement with a chi2/DOF of 15.7/15. The couplings …

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Study Of The Pion Trajectory In The Photoproduction Of Leading Neutrons At Hera, S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli Mar 2005

Study Of The Pion Trajectory In The Photoproduction Of Leading Neutrons At Hera, S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides, S. Magill, S. Miglioranzi, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, A. Montanari, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli

Faculty Publications

Energetic neutrons produced in ep collisions at HERA have been studied with the ZEUS detector in the photoproduction regime at a mean photon-proton center-of-mass energy of 220 GeV. The neutrons carry a large fraction 0.64

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Deconvolution Analysis Of Laser Pulse Profiles From 3-D Ladar Temporal Returns, Michael D. Walter Mar 2005

Deconvolution Analysis Of Laser Pulse Profiles From 3-D Ladar Temporal Returns, Michael D. Walter

Theses and Dissertations

Three-dimensional laser imaging systems offer important advantages for battlefield applications, such as night-time targeting and tactical reconnaissance. Recently developed technologies used by coherent detection systems that collect temporally resolved images include arrays of Avalanche Photo-Diodes (APD), Geiger mode APDs, and photo-diodes. Frequently, LADAR systems produce waveforms from each detector that characterize the convolution of the transmitted laser pulse with the target surface. The pulse convolution generates uncertainty as to the precise location of a target surface, which can severely impact various weapon systems' targeting capability. This work analyzes two deconvolution techniques: Wiener filtering and an iterative process derived from the …

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Measurement Of The ΛB0 Lifetime In The Decay ΛB0 → J/Ψλ0 With The D0 Detector, V. M. Abazov, Gregory Snow, D0 Collaboration Mar 2005

Measurement Of The ΛB0 Lifetime In The Decay ΛB0 → J/Ψλ0 With The D0 Detector, V. M. Abazov, Gregory Snow, D0 Collaboration

Gregory Snow Publications

We present measurements of the Λb0 lifetime in the exclusive decay channel Λb0 → J/ψΛ0, with J/ψ → μ+μ- and Λ0 → pπ-, the B0 lifetime in the decay Λ0 → J/ψKs0 with J/ψ → μ+μ- and Ks0 → π+π-, and the ratio of these lifetimes. The analysis is based on approximately 250 pb-1 of data recorded with the D0 detector in pp̅ collisions at √s = …

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