Bulletin of the American Physical Society
2009 APS April Meeting
Volume 54, Number 4
Saturday–Tuesday, May 2–5, 2009; Denver, Colorado
Session E1: Poster Session I (4:30-6:45pm) |
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Sponsoring Units: APS Room: Plaza Exhibit |
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E1.00001: ASTROPHYSICS |
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E1.00002: Recoil Redsfhit with Coherence C.F. Gallo ``Recoil Redshift'' is due to the elastic interaction of photons/light with any individual electron, proton, ion, atom or molecule. This generalized Compton effect describes an individual photon-particle interaction where Energy, Linear Momentum and Angular Momentum are conserved, with NO change in the internal energy of the particle. Per Compton, the lost photon energy is zero in the forward photon propagation direction, and the energy loss increases with scattering angle. This is an INDIVIDUAL INcoherent process. To describe collective coherent effects, add/include Huygens forward reconstruction from multiple photon/particle redshifted scatterings. A coherent redshift will occur if the scattered photons' energies are WITHIN the initial linewidth. This yields an asymmetrically broadened redshifted line in the forward coherent direction with clear imaging properties. This is a coherent redshifted version of Rayleigh scattering which assumes identical non-redshifted photons. BUT the Compton Conservation energy-loss process must occur. The search for this small Recoil redshift is a good research project for ultra- precise ``frequency combs'' in gases (atomic and molecular), plasmas and combinations. [Preview Abstract] |
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E1.00003: Rossby Vortex Instability associated with Gaps in Disks Cong Yu, Hui Li, Shengtai Li We study the stability of a thin (2D) and nonmagnetized accretion disk with a dip/gap structure. This is motivated by the studies that a massive protoplanet can induce a dip/gap in a protoplanetary disk. Using linear theory analysis, we show that such a gap is unstable to nonaxisymmetric modes. We have performed 2D nonlinear disk simulations to confirm our linear analysis. Vortices are found to be generated at both edges of the dip/gap.We also include the effects of disk viscosity and planet in our simulation. We find a critical value of viscosity, larger than which, the vortex instability would be suppressed. This explains why many previous simulations did not observe such an instability. The inclusion of a planet does not affect the initial exponential growth phase of the instability but it does influence the non-linear saturation of the instability. The existence of these vortices could have important implications for understanding the planet migration rate, eccentricity and asymptotic mass of the planet. [Preview Abstract] |
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E1.00004: MOND using a probabilistic approach Usha Raut MOND has been proposed as a viable alternative to the dark matter hypothesis. In the original MOND formulation [1], a modification of Newtonian Dynamics was brought about by postulating new equations of particle motion at extremely low accelerations, as a possible explanation for the flat rotation curves of spiral galaxies. In this paper, we attempt a different approach to modify the usual force laws by trying to link gravity with the probabilistic aspects of quantum mechanics [2]. In order to achieve this, one starts by replacing the classical notion of a continuous distance between two elementary particles with a statistical probability function, $\Pi$. The gravitational force between two elementary particles then can be interpreted in terms of the probability of interaction between them. We attempt to show that such a modified gravitational force would fall off a lot slower than the usual inverse square law predicts, leading to revised MOND equations. In the limit that the statistical aggregate of the probabilities becomes equal to the usual inverse square law force, we recover Newtonian/Einstein gravity.\\[3pt] [1] Milgrom, M. 1983, ApJ, 270, 365 \newline [2] Goradia, S. 2002, .org/pdf/physics/0210040 [Preview Abstract] |
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E1.00005: The observational signature of helical magnetic fields in parsec scale AGN jets Eric Brown, Maxim Lyutikov, Preeti Kharb While most jet formation models predict helical magnetic fields, their observational signature has yet to be confirmed. Observing how quantities change along the axis perpendicular to the jet flow may allow us to test the prediction of helical fields. We present calculations showing how the synchrotron intensity, fractional linear polarization, and spectral index to change across a jet with a helical magnetic field structure. These results are then compared with VLBI observations of resolved parsec scale jets. [Preview Abstract] |
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E1.00006: Simulation based evaluation of the designs of the Advanced Gamma-ray Imageing System (AGIS) Slava Bugaev, James Buckley, Seth Digel, Stephen Funk, Alex Konopelko, Henric Krawczynski, Steohan LeBohec, Gernot Maier, Vladimir Vassiliev The AGIS project under design study, is a large array of imaging atmospheric Cherenkov telescopes for gamma-rays astronomy between 40GeV and 100 TeV. In this paper we present the ongoing simulation effort to model the considered design approaches as a function of the main parameters such as array geometry, telescope optics and camera design in such a way the gamma ray observation capabilities can be optimized against the overall project cost. [Preview Abstract] |
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E1.00007: Correcting binary pulsar merger rates for spin evolution and orientation Richard O'Shaughnessy, Chunglee Kim State-of-the-art empirical estimates for gravitational wave merger rates of pulsar binaries depend linearly on the fraction of sky the observed pulsar's beam covers, a quantity that has only rarely been precisely measured. The opening angle of pulsars has long been known to evolve with the spin period, decreasing both at very short and very long periods. Pulsars may align with their spin axis on long timescales as well as spin down (and therefore change opening angle). Both effects must be included in any estimate of the beaming fraction of a pulsar with unknown beaming geometry. Unfortunately, when merger rates for binary compact objects were last estimated, the beaming angle for most pulsars was estimated by the value of the beaming fraction for just two canonical binary pulsars. In this paper we revisit the observed binary pulsars, particularly white dwarf-neutron star pulsars, to examine the sensitivity of merger rate predictions to different assumptions regarding opening angle and alignment. [Preview Abstract] |
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E1.00008: The Advanced Gamma-ray Imaging System (AGIS): Real Time Stereoscopic Array Trigger K. Byrum, J. Anderson, J. Buckley, T. Cundiff, J. Dawson, G. Drake, C. Duke, B. Haberichter, H. Krawzcynski, F. Krennrich, A. Madhavan, M. Schroedter, A. Smith Future large arrays of Imaging Atmospheric Cherenkov telescopes (IACTs) such as AGIS and CTA are conceived to comprise of 50 - 100 individual telescopes each having a camera with 10**3 to 10**4 pixels. To maximize the capabilities of such IACT arrays with a low energy threshold, a wide field of view and a low background rate, a sophisticated array trigger is required. We describe the design of a stereoscopic array trigger that calculates image parameters and then correlates them across a subset of telescopes. Fast Field Programmable Gate Array technology allows to use lookup tables at the array trigger level to form a real-time pattern recognition trigger tht capitalizes on the multiple view points of the shower at different shower core distances. A proof of principle system is currently under construction. It is based on 400~MHz FPGAs and the goal is for camera trigger rates of up to 10~MHz and a tunable cosmic-ray background suppression at the array level. [Preview Abstract] |
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E1.00009: The Advanced Gamma-ray Imaging System (AGIS): Schwarzschild-Couder (SC) Telescope Mechanical and Optical System Design V. Guarino, V. Vassiliev, J. Buckley, K. Byrum, A. Falcone, S. Fegan, J. Finley, D. Hanna, P. Kaaret, A. Konopelko, H. Krawczynski, F. Krennrich, R. Romani, R. Wagner, M. Woods The concept of a future ground-based gamma-ray observatory, AGIS, in the energy range 20 GeV to 200 TeV is based on an array of 50-100 imaging atmospheric Cherenkov telescopes (IACTs). The anticipated improvement of AGIS sensitivity, angular resolution, and reliability of operation imposes demanding technological and cost requirements on the design of IACTs. In this submission, we focus on the optical and mechanical systems for a novel Schwarzschild-Couder two-mirror aplanatic optical system originally proposed by Schwarzschild. Emerging new mirror production technologies based on replication processes, such as cold and hot glass slumping, cured CFRP, and electroforming, provide new opportunities for cost effective solutions for the design of the optical system. We explore capabilities of these mirror fabrication methods for the AGIS project and alignment methods for optical systems. We also study a mechanical structure which will provide support points for mirrors and camera design driven by the requirement of minimizing the deflections of the mirror support structures. [Preview Abstract] |
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E1.00010: Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS) R.G. Wagner, K. Byrum, G. Drake, S. Funk, N. Otte, A. Smith, H. Tajima, D. Williams The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. It is being designed to achieve a significant improvement in sensitivity compared to current Imaging Air Cherenkov Telescope (IACT) Arrays. One of the main requirements in order that AGIS fulfills this goal will be to achieve higher angular resolution than current IACTs. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, i.e. two to three times smaller than for current IACT cameras. Here we present results from testing of alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). [Preview Abstract] |
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E1.00011: The non-thermal X-ray filaments in young Supernova Remnants David Lomiashvili The nature of the non-thermal X-ray filaments in young Supernova Remnants (SNR) is still unclear. In this work we provide simulated spatially resolved emission spectra in the X-ray. We use a one-dimensional diffusion-loss equation to describe the propagation of non-thermal electrons near the shock of a young SNR and to calculate spatially resolved emission spectra in the X-ray. The results suggests that the high-energy electrons are diffused further and hence the width of the radial profile doesn't depend on the observed frequency. [Preview Abstract] |
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E1.00012: Multiband Cepheid PL relations from OGLE III measurements and the impact on Hubble's constant R.Q. Dienhoffer, S. Kanbur, C. Ngeow The Cepheid PL relation is of fundamental importance in estimating Hubble's constant. The Key Project has estimated H0 with an accuracy of 10{\%}. Recent work has suggested that a CMB independent estimate of H0 accurate to less than 5{\%} can constrain the equation of state for Dark Energy. In this work, we show that one of the fundamental assumptions underlying the PL relation, that it is linear, is not supported by recent observations. We show that this can affect estimates of H0 by as much as 1-2{\%}: small but perhaps important in the context of reducing errors on H0 to less than 5{\%}. [Preview Abstract] |
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E1.00013: Simulating deep surveys of the Galactic Plane with the Advanced Gamma-ray Imaging System (AGIS) Stefan Funk, Seth Digel The pioneering survey of the Galactic plane by H.E.S.S., together with the northern complement now underway with VERITAS, has shown the inner Milky Way to be rich in TeV-emitting sources; new source classes have been found among the H.E.S.S. detections and unidentified sources remain. In order to explore optimizations of the design of an Advanced Gamma-ray Imaging System (AGIS)-like instrument for survey science, we constructed a model of the flux and size distributions of Galactic TeV sources, normalized to the H.E.S.S. sources but extrapolated to lower flux levels. We investigated potential outcomes from a survey with the order of magnitude improvement in sensitivity and attendant improvement in angular resolution planned for AGIS. Studies of individual sources and populations found with such a sensitivity survey will advance understanding of astrophysical particle acceleration, source populations, and even high-energy cosmic rays via detection of the low-level TeV diffuse emission in regions of high cosmic-ray densitiy. [Preview Abstract] |
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E1.00014: AGN Science with AGIS Paolo Coppi AGIS, a proposed future gamma-ray telescope consisting of a square km array of ~50 atmospheric Cherenkov telescopes, will provide a powerful new view of the high energy universe. The combination of its increased sensitivity (a factor 10 over current observatories), increased survey capabilities, and a low energy threshold ($<30$ GeV) that allows observations at energies not subject to absorption on extragalactic background light will result in a dramatic increase in the number of AGN accessible at high energies. The overall number of ``TeV blazar" AGN, those detected by current ground-based observatories, should increase by a factor ~30 or more with a corresponding increase in the number of these that can be monitored at high statistical significance to test emission models rigorously. More excitingly, AGIS may also begin to pick up entirely new classes of AGN such as radio galaxies with X-ray emitting hotspots at large distances from the central engine, providing further insight into the outflows from AGN. The low AGIS threshold energy will also allow significant source overlap with objects detected by the recently launched Fermi gamma-ray space observatory at lower, GeV energies. AGIS will significantly improve on the localization and variability monitoring of the Fermi sources it sees. [Preview Abstract] |
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E1.00015: VERITAS Observation of Very High Energy Gamma-Ray Emission from 1ES1218+30.4 Asif Imran VERITAS, the Very Energetic Radiation Telescope Array System, is an array of four imaging Atmospheric Cherenkov telescopes located in southern Arizona. The VERITAS collaboration conducted an observation campaign of the high-frequency-peaked BL Lac object 1ES1218+30.4 during the 2008-2009 season. We will present spectral measurements and a light curve from these observations. [Preview Abstract] |
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E1.00016: ABSTRACT WITHDRAWN |
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E1.00017: Global Constraints on Astrophysical Jet and Lobe Systems from the Jet and ICM Interactions Hui Li, Hao Xu X-ray and radio observations of galaxy clusters have revealed a wealth of structure in the intra-cluster medium (ICM) associated with extragalactic radio sources. Structures in the form of large scale cavities and weak shocks provide a reliable gauge of the mechanical output of extragalactic radio jets launched by AGNs. By analyzing the properties of the jet/lobe and ICM interactions, we discuss how these observations can give strong constraints on the nature of AGN outflows. We present three-dimensional relativistic MHD simulations of the jet/lobe formation and its interactions with the background ICM. The jet/lobe formation is determined by a global current system. We investigate the effects of flows on the energetics and stability of the jet-lobe system. Simulations are compared with observations of X-ray cavities in clusters and the possibility of lobes being magnetically dominated on global scales will be discussed. [Preview Abstract] |
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E1.00018: Conduction, Stability, Dissipation in Intercluster Plasma Maxim Lyutikov Magnetic fields are dynamically subdominant in the intercluster medium, yet they may determine its dissipative properties, stability of embedded structures and transition to turbulence. First, a subtle dynamical effect, magnetic draping, leads to suppression of conductivity and dynamical stability of narrow cooling fronts and AGN blown cavities. Next, I will discuss dissipative process in collisionless plasma of ICM and argue that development of anisotropic instabilities determines the dissipation efficiency of subsonic flows. Boundary layers between interacting flows, which determine transition to turbulence, are also strongly affected by the presence of magnetic fields. [Preview Abstract] |
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E1.00019: The double pulsar: tomography of pulsar magnetosphere and a new GR test Maxim Lyutikov The long awaited discovery of the binary radio pulsar system, PSR J0737-3039A/B, surpassed most expectations, both theoretical and observational, as a tool to probe general relativity, stellar evolution and pulsar theories. Unexpectedly, the faster pulsar A is eclipsed once per orbit while the slower pulsar B shows orbital-dependent variations of intensity. I will describe a model of eclipses which reproduces the complicated observed light curve down to intricate details. This proves the long standing assumption of dipolar magnetic fields of neutron stars and gives a tool to probe details of magnetospheric structure and pulsar emission generation mechanisms. The model also provides a quantitative measurement of relativistic spin precession and offers a new test of theories of gravity. [Preview Abstract] |
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E1.00020: VERITAS Observations of the Supernova Remnant IC 443 Brian Humensky Supernova remnants (SNRs) are widely considered to be the strongest candidate for the source of cosmic rays below the knee around $3 \cdot 10^{15}\ \textrm{eV}$. In the last few years, TeV gamma-ray observations of SNRs have opened a new window on the high-energy processes occurring in their shock fronts. VERITAS, an array of four gamma-ray telescopes located at the Whipple Observatory in southern Arizona, has an active program of SNR observations. Recent results include the co-discovery (along with MAGIC) of TeV emission from IC 443. In the case of IC 443, a deep observation reveals that the emission is extended and coincident in space with the site of interaction between the expanding shell of the SNR and a nearby molecular cloud. These results and their implications for the nature of the cosmic rays - hadronic or electronic - accelerated in the remnants will be discussed. [Preview Abstract] |
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E1.00021: Optimizing Finite Mirrors for Advanced Gravitational Wave Detectors David Tsang, Andrew Lundgren, Ruxandra Bondarescu, Simon Fong, Mihai Bondarescu We discuss mirror design for advanced interferometric gravitational wave detectors including finite mirror effects. We perform a search for the lowest value of thermal noise that can be achieved in LIGO by changing the shape of mirrors, while fixing the mirror radius and maintaining a low diffraction loss. We use a genetic algorithm to attempt to find a global minimum of thermal noise within the given constraints. Lowering the thermal noise can significantly increase the strain sensitivity of the detector in the most sensitive frequency band. This frequency region includes gravitational radiation expected from one known young pulsar as well as binary coalescences of neutron stars and black holes. [Preview Abstract] |
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E1.00022: Identification of clear atmospheric conditions in a search for exotic candidates at the Pierre Auger Observatory David Starbuck, David Schuster, Lawrence Wiencke Atmospheric data from the Pierre Auger Observatory's Central Laser Facility (CLF) and other sources were analyzed to identify clear, cloudless periods of extended duration. The purpose of this study is to assist an on-going search for exotic particle signatures. The search examines the longitudinal profiles of extensive air-showers recored by the fluorescence detector. Anomalous longitudinal profiles of potential interest as exotic candidates are typically caused by cloudy or hazy atmospheric conditions. These potential signatures can be eliminated by restricting the search to periods of clear atmospheric conditions. [Preview Abstract] |
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E1.00023: Kinematical Conformal Cosmology Gabriele Varieschi We present an alternative cosmology based on conformal gravity. Unlike past similar attempts our approach is a purely kinematical application of the conformal symmetry to the Universe. As a result of this novel approach we obtain a closed-form expression for the cosmic scale factor R(t) and new fundamental cosmological parameters $\gamma $ and $\delta $ are introduced and evaluated. This emerging new cosmology does not seem to possess any of the controversial features of the current standard model, such as the presence of dark matter, dark energy or of a cosmological constant. Our kinematical conformal cosmology is then able to explain the anomalous acceleration of the Pioneer spacecraft, as due to a local region of gravitational blue-shift. From the reported values of the Pioneer anomaly we also compute the current value of our first fundamental parameter, $\gamma $ = 1.94 $\times $ 10$^{-28}$ cm$^{-1}$. Our second fundamental parameter, $\delta $ = 3.83 $\times $ 10$^{-5}$, interpreted as the current value of a cosmological time variable, is derived from a detailed fitting of type Ia Supernovae ``gold-silver'' data, producing Hubble plots of the same quality of those obtained by standard cosmology, but without requiring any dark matter or dark energy contribution. If further experiments will confirm the presence of an anomalous frequency blue-shift in the outer region of the Solar System, as described by our model, kinematical conformal cosmology might become a viable alternative to standard cosmological theories. [Preview Abstract] |
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E1.00024: The weightlessness of photons in a local system of reference, the cross sections for the plasma redshift, and the Raman scattering on the plasma frequency Ari Brynjolfsson The weightlessness of photons in the local system of reference (repulsion in a distant system of reference) and the two cross sections change in a fundamental way the cosmological perspective. Many experiments have verified these effects. But due to their revolutionary consequences, many physicists are reluctant to believe them. I propose therefore that the experiments discussed in section 7 of arXiv:astro-ph/0401420 be funded and carried out by independent scientists. The weightlessness of photon experiments are more costly, but measuring the plasma redshift of optical star-light penetrating the solar corona during solar eclipse is possible with the existing equipment of many observatories. The redshifts decrease with the distance from the solar center. For R/R$_{0} $ = 1.1, 1.4, and 2.0, from the solar center, the additional redshifts will be 2.6, 1.4, and 0.4 in parts per million, respectively. Every line from each star will be redshifted by the same amount. For better accuracy, we can compare their redshifts against lines formed in the Earth's atmosphere. [Preview Abstract] |
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E1.00025: Prospects for Dark Matter Measurements with the Advanced Gamma Ray Imaging System (AGIS) James Buckley AGIS, a concept for a future gamma-ray observatory consisting of an array of ~50 atmospheric Cherenkov telescopes, would provide a powerful new tool for determining the nature of dark matter and its role in structure formation in the universe. The advent of more sensitive direct detection experiments, the launch of Fermi and the startup of the LHC make the near future an exciting time for dark matter searches. Indirect measurements of cosmic-ray electrons may already provide a hint of dark matter in our local halo. However, gamma-ray measurements will provide the only means for mapping the dark matter in the halo of our galaxy and other galaxies. In addition, the spectrum of gamma-rays (either direct annihilation to lines or continuum emission from other annihilation channels) will be imprinted with the mass of the dark matter particle, and the particular annihilation channels providing key measurements needed to identify the dark matter particle. While current gamma-ray instruments fall short of the generic sensitivity required to measure the dark matter signal from any sources other than the (confused) region around the Galactic center, we show that the planned AGIS array will have the angular resolution, energy resolution, low threshold energy and large effective area required to detect emission from dark matter annihilation in Galactic substructure or nearby Dwarf spheroidal galaxies. [Preview Abstract] |
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E1.00026: Cosmic Microwave Background Constraint on the Rotation of the Universe Shi Chun Su, Ming Chung Chu Models of a rotating universe have been studied widely since G{\"o}del [1], who showed an example that is consistent with General Relativity (GR). By now, rotating universes have been discussed comprehensively in the framework of some types of Bianchi's models, such as Type V, VII and IX [2,3]. However, most of those models are ruled out by cosmological data, such as those of Cosmic Microwave Background Anisotropies (CMBA), which strongly prefers a homogeneous and isotropic model. As a result, it is crucial to discuss the rotation of the universe as a perturbation in the Robertson-Walker metric and to constrain the rotating speed by cosmological data. Here, we will study the effects of rotation perturbations on CMBA in a $\Lambda$-CDM universe. We derive the general form of the metric (up to 2nd- order perturbations) which is compatible with the rotation perturbation in a $\Lambda$-CDM universe. By comparing the 2nd- order Sachs-Wolfe effect due to the rotation with the CMBA data, we can then constrain the angular speed of the rotation. Reference: [1] K. Godel, Rev. Modern Phys. 21 (1949) 3, [2] S. Hawking, Mon. Not. R. astr. Soc. 142 (1969) 129, [3] J. D. Barrow et al., Mon. Not. R. astr. Soc. 213 (1984) 917 [Preview Abstract] |
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E1.00027: Predictability of Solar Flares Peter Mares, K.S. Balasubramaniam Solar flares are significant drivers of space weather. With the availability of high cadence solar chromospheric and photospheric data from the USAF's Optical Solar PAtrol Network (OSPAN; photosphere and chromosphere imaging) Telescope and the Global Oscillations Network Group (GONG; photosphere magnetic imaging), at the National Solar Observatory, we have gained insights into potential uses of the data for solar flare prediction. We apply the Principal Component Analysis (PCA) to parameterize the flaring system and extract consistent observables at solar chromospheric and photospheric layers that indicate a viable recognition of flaring activity. Rather than limiting ourselves to a few known indicators of solar activity, PCA helps us to characterize the entire system using several tens of variables for each observed layer. The components of the Eigen vectors derived from PCA help us recognize and quantify innate characteristics of solar flares and compare them. We will present an analysis of these results to explore the viability of PCA to assist in predicting solar flares. [Preview Abstract] |
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E1.00028: Measurement of the single top production cross section in the transverse missing energy plus jets sample Karolos Potamianos Standard model top quarks are produced mostly in pairs at the Tevatron through the strong force. However, the production of a single top quark per process is allowed through electroweak processes. We present a measurement of the the standard model single top production cross-section in proton-anti protons collisions at 1.96 TeV center of mass energy. The data collected with the CDF II detector at the Tevatron collider at Fermilab correspond to an integrated luminosity of 2.1 $fb^{-1}$. Until now, Tevatron experiments searched for single top only in events where one high energy electron or muon has been identi?ed, to suppress the huge QCD background. Here, we look for the first time at events where no electron or muon has been identi?ed, and where tau leptons decay hadronically and are reconstructed as jets in the calorimeter. Thus, we consider a signature of two b-jets, no leptons, and missing transverse energy. We present preliminary results as well as ongoing efforts in this search. [Preview Abstract] |
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E1.00029: Upgrading the VERITAS Array Jamie Holder The VERITAS array, consisting of four 12m diameter Cherenkov telescopes, has been observing the Northern sky in TeV gamma-rays for three years with high sensitivity (1 percent of the Crab Nebula flux in 50 hours), and excellent energy and angular resolution. Exciting new results on a variety of TeV gamma-ray sources, both galactic and extra-galactic, have already been obtained. Technical developments and Monte Carlo simulation results now suggest that substantial further improvements to the array performance are possible, and that an upgrade is timely and worthwhile. Here we present some of the preferred options. [Preview Abstract] |
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E1.00030: Camera Concepts for the Advanced Gamma-Ray Imaging System (AGIS) Adam Nepomuk Otte The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Each telescope is equipped with a camera that detects and records the Cherenkov-light flashes from air showers. The camera is comprised of a pixelated focal plane of blue sensitive and fast (nanosecond) photon detectors that detect the photon signal and convert it into an electrical one. The incorporation of trigger electronics and signal digitization into the camera are under study. Given the size of AGIS, the camera must be reliable, robust, and cost effective. We are investigating several directions that include innovative technologies such as Geiger-mode avalanche-photodiodes as a possible detector and switched capacitor arrays for the digitization. [Preview Abstract] |
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E1.00031: Results Obtained with a Prototype Negative Ion Time Projection Chamber (NITPC) Designed for Measuring the Prompt X-ray Emission from Gamma-ray Bursts Zachary Prieskorn, J.E. Hill, P. Kaaret, J.K. Black, K. Jahoda Gas based time projection chambers (TPCs) have been shown to be highly sensitive X-ray polarimeters having excellent quantum efficiency while at the same time achieving large modulation factors . To observe polarization of the prompt X-ray emission of a Gamma-ray burst (GRB), a large area detector is needed. Diffusion of the electron cloud in a standard TPC could be prohibitive to measuring good modulation when the drift distance is large. We propose using a negative ion TPC (NITPC) with Nitromethane (CH$_{3}$NO$_{2})$ as the electron capture agent. An NITPC will have improved diffusion characteristics due to the thermal coupling of the negative ion to the surrounding gas and reduced electronic power consumption due to the slower velocity of the negative ions. We present results from tests of a single and double GEM TPC and NITPC. SciEnergy GEMs of 3x3 cm$^{2}$ and 2x5 cm$^{2}$ were used in the experiment and tested with various concentrations and pressures of P10, NeCO$_{2}$ and NeCO$_{2}$CH$_{3}$NO$_{2}$. Gain curves, photoelectron tacks and modulation curves will be presented for each instrument. [Preview Abstract] |
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E1.00032: Development of Camera Electronics for the Advanced Gamma-ray Imaging System (AGIS) Hiroyasu Tajima AGIS, a next generation of atmospheric Cherenkov telescope arrays, aims to achieve a sensitivity level of a milliCrab for gamma-ray observations in in the energy band of 40~GeV to 100~TeV. Such improvement requires cost reduction of individual components with high reliability in order to equip the order of 100 telescopes necessary to achieve the sensitivity goal. We are exploring several design concepts to reduce the cost of camera electronics while improving their performance. We have developed test systems for some of these concepts and are testing their performance. Here we present test results of the test systems. [Preview Abstract] |
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E1.00033: Mass, Energy, Space And Time System Theory---MEST A way to help our earth DaYong Cao Things have their physical system of the mass, energy, space and time of themselves-MEST (for short there in after). It can unite both the macrophysics and microphysics and can unite both MEST equation of atomic spectrum and MEST equation of nine planets. The solar system is mass-energy center, and the space-time wave is around. The black hold is the space-time center, and the dark matter-energy wave is around. The dark matter-energy wave is from the black hold like that the light is from sun. (like black hole) The light can give the planet the repulsion, and can produce negative curvature of the space-time of the planet; (like sun)The dark matter-energy can give the planet the gravitation, and can produce positive curvature of the space-time of the planet . The Dark matter-energy will take the asteroid and the comet impacted near our earth. The Dark matter-energy can produce dark planet. The Oort cloud is a dark planet belt. The comet is dark planet from the Oort cloud. There are four terrestrial planets which are mass-energy center like solar system; and there are five Jovian planets which are gas (space-time) center like black hole system. Because them be influenced by dark matter-energy. And Jupiter's orbital velocity be reduced by it too. We can use the Dark matter-energy to reduce the greenhouse effect, use it to control nuclear fusion and produce the quantum black hole, and arrest the asteroid and the comet who impacted near our earth. [Preview Abstract] |
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E1.00034: Mining black hole binary merger waveforms: characterising spinning intermediate mass black holes Birjoo Vaishnav, Richard O'Shaughnessy, Deirdre Shoemaker, Frank Herrmann, Ian Hinder Coalescing spinning black hole binaries will imprint information about their initial and final mass and spin configuration on their emitted waves. ~ Though this imprint is relatively well understood before and after the merger phase, an understanding of the strongest, most nonlinear waves requires full numerical relativity. ~ We present an analysis of this imprint for specific waveforms from a lower-dimensional subspace of the full binary configuration space. ~More specifically, we estimate how many distinguishable quadrupolar waveforms are required to sparsely match any waveform in our subspaces. All waveforms used in our estimate have been realized numerically. [Preview Abstract] |
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E1.00035: The THEMIS Magnetospheric Breach Discovery and an Anomaly in the Global Distribution of Petroglyphs; MHD Instabilities Recorded by Mankind in Antiquity Anthony Peratt, W. Fay Yao, P. Bustamante, R. Tuki The recent THEMIS spacecraft discovery of two very large holes in the Earth's magnetosphere helps explain an anomaly in the global distribution of petroglyphs on our planet [1]. Previously, we reported a world wide GPS logging of some 4 million of these objects, each a picture of a filamental MHD instability carved in rock [2, 3]. In all cases, the field-of-view of the petroglyphs was true south with an off-horizon inclination between 21 -- 31 degrees. However, in a complete survey of the braided lava tube caves on Easter Island, petroglyphs were also found in long, true-north shafts, 50 m or more in length. This observation had been noted in natural shafts of similar lengths in the Columbia River Basin. 1. W. Li, To be published in the \textit{Journal of Geophysical Research}. 2. A. L. Peratt \textit{et al}, \textit{Trans. Plasma Sci}. 35. 778. 2007. 3. A. L. Peratt and W. F. Yao, \textit{Physica Scripta}, T130, 2008. [Preview Abstract] |
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E1.00036: PARTICLES AND FIELDS |
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E1.00037: Observation of Single Top Quark Production at the DZero Experiment Cecilia Gerber, Ann Heinson, Reinhard Schwienhorst Using $1~\rm{fb^{-1}}$ of data, D0 reported an evidence for the production of single top quarks at 3 standard deviations, in 2007. Three different state-of-the-art multivariate techniques: Decision Trees (DT), Matrix Elements (ME), and Bayesian Neural Networks (BNN), were used to identify the small signal from the overwhelming backgrounds. A weighted average of measurements from all three analyses was then done via the Best Linear Unbiased Estimate (BLUE) to further enhance the sensitivity. Here we present a multivariate approach to combining results, which takes as input the output discriminants of the DT, ME, and BNN analyses. Preliminary results suggest a significant improvement upon the simple weighting technique. [Preview Abstract] |
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E1.00038: On a Heuristic Point of View About Inertial Deconfinement of Quarks V. Alexander Stefan I propose a novel heuristic method for the deconfinement of quarks.\footnote{M. Gell-Mann. \textbf{The Quark and the Jaguar: Adventures in the Simple and the Complex }(New York, NY: W.H. Freeman and Co., 1994) [cf. M. Gell-Mann, \textit{The Garden of Live Flowers} in: V. Stefan (Editor), \textbf{Physics and Society. Essays Honoring Victor Frederick Weisskopf }(Springer, 1998), pp. 109-121].} It proceeds in two phases. Firstly, a frozen hydrogen pellet is inertially confined by the ultra-intense lasers up to a solid state density. Secondly, a solid state nano-pellet is ``punched'' by a femtosecond TeV-photon beam created in the beat wave driven free electron laser (BW-FEL),\footnote{V. Alexander Stefan. \textbf{Beat Wave Driven Free Electron Laser }(S-U-Press, 2002, La Jolla, CA)[cf. V. Stefan et. al., \textbf{Bull.~Am. Phys. Soc.} 32, No. 9, 1713 (1987)]} leading to the ``rapture'' (in a ``karate chop'' model) of the ``MIT Bag''\footnote{J. I. Friedman and H. Kendall, \textit{Viki}, in: V. Stefan (Editor), \textbf{Physics and Society. Essays Honoring Victor Frederick Weisskopf }(Springer, 1998), pp. 103-108].\par } before the asymptotically free quarks move apart. The threshold ``rapture force'' of the TeV photon is 10$^{8}$N. [Preview Abstract] |
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E1.00039: Double Parton scattering in 2fb$^{-1}$ of CDF II W-$>$e$\upsilon$ + jets data Varsha Ramakrishnan, Duncan Carlsmith Search for Evidence of Double Parton Scattering events in W-$>$e$\upsilon $ + jets in 2fb$^{-1}$ CDF II data is presented. Silicon and COT tracking system is used for vertex reconstruction of the Low energy jets. Multiple Interactions (two different ppbar collisions) distinguished by applying a cut on $\Delta $Z between electron track Z and Jet Z Vertex. To discriminate Signal from the background, Azimuthal angular distributions are fit for single plus multiple parton collision model. Work is in progress to obtain the Double Parton fraction present in data. [Preview Abstract] |
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E1.00040: CMS plans for the measurement of the Z decays as a differential function of Z rapidity in the electron channel Jason Haupt Plans for a measurement of the Z differential cross-section are presented with 100 inverse-pb of fully simulated and reconstructed MC. This includes the method for determining electron efficiency and acceptance as well as a discussion of statistical and systematic errors. [Preview Abstract] |
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E1.00041: The 5th Generation model of Particle Physics Theodore Lach The Standard model of Particle Physics is able to account for all known HEP phenomenon, yet it is not able to predict the masses of the quarks or leptons nor can it explain why they have their respective values. The Checker Board Model (CBM) predicts that there are 5 generation of quarks and leptons and shows a pattern to those masses, namely each three quarks or leptons (within adjacent generations or within a generation) are related to each other by a geometric mean relationship. A 2D structure of the nucleus can be imaged as 2D plate spinning on its axis, it would for all practical circumstances appear to be a 3D object. The masses of the hypothesized ``up'' and ``dn'' quarks determined by the CBM are 237.31 MeV and 42.392 MeV respectively. These new quarks in addition to a lepton of 7.4 MeV make up one of the missing generations. The details of this new particle physics model can be found at the web site: checkerboard.dnsalias.net. The only areas were this theory conflicts with existing dogma is in the value of the mass of the Top quark. The particle found at Fermi Lab must be some sort of composite particle containing Top quarks. [Preview Abstract] |
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E1.00042: BESIII TOF monitoring system Qian Liu, Frederick Harris, James Kennedy, Steve Olsen, Marc Rosen, Chengping Shen, Garry Varner, Yuekun Heng, Zhijia Sun, Jinjie Wu, Kejun Zhu, Qi An, Changqing Feng, Shubin Liu A monitor system of Beijing Spectrometer (BESIII) Time of flight (TOF) has been fabricated, installed and operated successfully during the BESIII running. The light source is 442~443 nm laser diode, which is stable and provides a pulse width as narrow as 50 ps and a peak power as large as 2.6 W. Two optical-fiber bundles with a total of 512 optical fibers are used to distribute the light to the TOF counters. The system is used to check the performance of each TOF daily during BESIII running. The paper presents the current performance of the system. [Preview Abstract] |
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E1.00043: Determination of Neutrino Mass Hierarchy from the Deep Core Extension of the IceCube data on Atmospheric Neutrinos Soebur Razzaque, Olga Mena, Irina Mocioiu Measurement of $\sim$ 10 GeV atmospheric neutrinos over a baseline of the Earth's diameter can be used to probe neutrino mass hierarchy dominantly through muon neutrino disappearance channel. An extension of the IceCube array at the South Pole is currently under construction which will form a 5-10 Mega ton volume of densely packed phototubes. Positioned in the bottom center of the full IceCube array, it will make possible for this Deep Core to detect muons with energy as low as $\sim$ 5 GeV and coming from below. The full IceCube array will provide veto to down-going high-energy muons. Theoretical results which are presented here for an exposure of 100 Mt-yr show that the IceCube Deep Core can determine neutrino mass hierarchy if the true value of the currently unknown neutrino mixing parameter $\theta_{13}$ is close to the present upper bound. [Preview Abstract] |
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E1.00044: Search For Heavy Stable Charged Particles at the CMS Experiment Seth Cooper Heavy Stable Charged Particles (HSCPs) are predicted by a number of diferent supersymmetric models, and would be observable using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). An HSCP produced at the LHC would have momentum on the order of several hundred GeV, but would travel slowly because of its large mass. This makes it possible to obtain the mass of an HSCP using velocity measurements. Two methods of determining the velocity will be discussed, along with the expected discovery reach of the search. [Preview Abstract] |
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E1.00045: Experimental Basis for IED Particle Model J. Zheng-Johansson The internally electrodynamic (IED) particle model is built on three experimental facts: a) electric charges present in all matter particles, b) an accelerated charge generates electromagnetic (EM) waves by Maxwell's equations and Planck energy equation, and c) source motion gives Doppler effect. A set of well-kwon basic particle equations have been predicted based on first-principles solutions for IED particle (e.g. arxiv:0812.3951, J Phys CS{\bf 128}, 012019, 2008); the equations are long experimentally validated. A critical review of the key experiments suggests that the IED process underlies these equations not just sufficiently but also necessarily. E.g.: 1) A free IED electron solution is a plane wave $\psi \dot{=} Ce^{i(k_d X-\omega T)}$ requisite for producing the diffraction fringe in a Davisson-Germer experiment, and of also all basic point-like attributes facilitated by a linear momentum $\hbar k_d $ and the model structure. It needs not further be a wave packet which produces not a diffraction fringe. 2)The radial partial EM waves, hence the total $\psi$, of an IED electron will, on both EM theory and experiment basis -not by assumption, enter two slits at the {\it same} time, as is requisite for an electron to interfere with itself as shown in double slit experiments. 3) On annihilation, an electron converts (from mass $m$) to a radiation energy $\hbar \omega$ without an acceleration which is externally observable and yet requisite by EM theory. So a charge oscillation of frequency $\omega$ and its EM waves must regularly present internal of a normal electron, whence the IED model. [Preview Abstract] |
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E1.00046: ABSTRACT WITHDRAWN |
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E1.00047: Alignment of the CMS muon system with tracks Sergey Senkin, James Pivarski, Alexei Safonov, Karoly Banicz As the name suggests, the Compact Muon Solenoid (CMS) features a full tracking spectrometer for identifying and measuring the momenta of muons. Every muon passes through 18-44 layers, providing a highly redundant track capable of validating and improving the momentum measurement from the inner tracker. But like any tracking system, its performance depends on precise knowledge of the positions of the tracking elements relative to one another and relative to the central CMS silicon tracker. We present techniques to align the muon chambers and layers with high-precision using tracks, and demonstrate the accuracy of one such technique using the first LHC beam from September of 2008. [Preview Abstract] |
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E1.00048: CMS Hadronic EndCap Calorimeter Upgrade Studies P-Terphenyl Deposited Quartz Plate Calorimeter Prototype Ugur Akgun Due to an expected increase in radiation damage under super-LHC conditions, we propose to substitute the scintillator tiles in the original design of the CMS hadronic endcap (HE) calorimeter with quartz plates. Quartz is proved to be radiation hard by various tests, but the light produced by quartz comes from Cerenkov process, and it is 100 times less than scintillation photons. To enhance the light production we treated the quartz plates with p-Terphenyl, and constructed a 20 layers calorimeter prototype. Here, we report the test beam results for hadronic and electromagnetic capabilities of the calorimeter prototype as well as radiation damage results for p-Terphenyl. [Preview Abstract] |
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E1.00049: UNDERGRADUATE RESEARCH |
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E1.00050: One Neutron Knockout from $^{45}$Cl D.C. Stoken, B.A. Hartl, K.E. Hosier, L.A. Riley, P.D. Cottle, K.W. Kemper, P. Adrich, T.R. Baugher, D. Bazin, J.M. Cook, C. Aa. Diget, A. Gade, D.A. Garland, T. Glasmacher, A. Ratkiewicz, K.P. Siwek, D. Weisshaar We report a one neutron knockout measurement from $^{45}$Cl conducted at the Coupled Cyclotron Facility of the NSCL at Michigan State University. The one-neutron knockout reaction $^ {9}$Be($^{45}$Cl, $^{44}$Cl)X was studied using gamma-ray spectroscopy. Gamma rays were detected using the Segmented Germanium Array (SeGA). Three gamma rays were observed that have not previously been reported. We present a proposed level scheme for $^{44}$Cl. Parallel momentum distributions were used to establish the angular momentum removed in populating two of the excited states and the ground state. [Preview Abstract] |
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E1.00051: Analysis of $^{36,38,40}$Si by Gamma Ray Spectroscopy of Fragmentation Reactions B.A. Hartl, K.E. Hosier, L.A. Riley, D.C. Stoken, P.D. Cottle, K.W. Kemper, P. Adrich, T.R. Baugher, D. Bazin, J.M. Cook, C. Aa. Diget, A. Gade, D.A. Garland, T. Glasmacher, A. Ratkiewicz, K.P. Siwek, D. Weisshaar We report the results of an experiment performed at the National Superconducting Cyclotron Laboratory (NSCL) where a $\approx$ 100 MeV/nucleon exotic cocktail beam with primary components $^{44}$S and $^{45}$Cl was fragmented in a $^{9}$Be reaction target to produce $^{36,38,40}$Si. The Gamma rays emitted by the reaction products were detected with the Segmented Germanium Array (SeGA), and the exotic nuclei produced were identified by the S800 magnetic spectrograph. The gamma-ray energy spectra observed are consistent with prior measurement [1]. In addition, we observed three additional gamma rays in $^{40}$Si. [1] C.M.Campbell et al., Phys.Lett. B 652, 169 (2007); C.M.Campbell et al., Phys.Rev.Lett. 97, 112501 (2006). [Preview Abstract] |
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E1.00052: Designing and Testing a Database for the Qweak Measurement Edward Holcomb, Damon Spayde, Tim Pote The aim of the Qweak experiment is to make the most precise determination to date, aside from measurements at the Z-pole, of the Weinberg angle via a measurement of the proton's weak charge. The weak charge determines a particle's interaction with Z-type bosons. According to the Standard Model the value of the angle depends on the momentum of the exchanged Z boson and is well-determined. Deviations from the Standard Model would indicate new physics. During Qweak, bundles of longitudinally polarized electrons will be scattered from a proton target. Elastically scattered electrons will be detected in one of eight quartz bars via the emitted Cerenkov radiation. Periodically the helicity of these electrons will be reversed. The difference in the scattering rates of these two helicity states creates an asymmetry; the Weinberg angle can be calculated from this. Our role in the collaboration was the design, creation, and implementation of a database for the Qweak experiment. The purpose of this database is to store pertinent information, such as detector asymmetries and monitor calibrations, for later access. In my talk I plan to discuss the database design and the results of various tests. [Preview Abstract] |
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E1.00053: Total production rate for neutrino-induced pair creation in a magnetic field Laura Johnson The role of magnetic fields on neutrino interactions can be very important in astrophysical environments where enormous field strengths exist and objects are sensitive to neutrino transport. One such interaction is the production of electron- positron pairs through the process $\nu \to \nu\,e\,\bar{e}$ in a strong background magnetic field. In addition to the usual integration over final momenta, the total pair-production rate involves a summation over all possible Landau levels associated with the electron and positron. The number of Landau states grows rapidly with increased magnetic field and increased energy which poses significant computational challenges. This talk will identify the difficulties associated with summing the total pair-production rate, the dominant terms contributing to the total rate, and will present methods of approximating the sum. [Preview Abstract] |
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E1.00054: Noninvasive Prospecting for Lunar Minerals John Meredith The establishment of a lunar base is planned as the first step in sending humans to explore our solar system. One of the essential ingredients for supporting a manned lunar base is oxygen. Significant deposits of the mineral ilmenite, a titanium-iron oxide, are thought to occur on or near the lunar surface; oxygen can readily be extracted from ilmenite. A potential noninvasive way of exploring for lunar ilmenite is with the use of a ground-penetrating radar system. In order to validate the approach, a ground-penetrating radar system will be used to explore for deposits of naturally occurring ilmenite in the state of Arkansas. Once the deposits have been identified by the ground-penetrating radar system, samples will be extracted from these deposits and analyzed for the presence of ilmenite. Our initial results indicate that a scanning electron microscope can determine the presence of ilmenite and validate the utility of using ground-penetrating radar as a noninvasive method of exploring for ileminate. Results from this ongoing project will be presented. [Preview Abstract] |
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E1.00055: Toward a Study of Synchronization in Quantum Mechanical Josephson Junction Arrays Robert Anthony, William Kenny, Brad Trees Numerical methods of simulating dissipative quantum systems were studied with an eye toward looking for evidence of quantum synchronization in Josephson Junction (JJ) arrays. JJs are of interest because of their potential application in quantum computing as quantum bits. Synchronization between JJs is an important step in realizing this application. Classical synchronization among JJs has already been studied, and we were able to replicate such synchronization among JJs in an array coupled to a nanomechanical oscillator (NMO). Quantum synchronization of JJs, however, has yet to be studied in detail, and is a major focus of our research. Quantum mechanically, various methods exist to model the dissipative interaction between JJs and their environment (damping), including the quantum jump method and the quantum state diffusion method. For example, in the quantum jump method, at random points in time, the system loses energy to its environment, and the system ``jumps'' down a quantum state. Using this method, we studied the two-state JJ (qubit) coupled to an NMO and the quantum kicked pendulum, in which the pendulum experiences a position-dependent angular impulse at regular time intervals. This poster focuses on describing the quantum jump method, both the theory behind it and its implementation. [Preview Abstract] |
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E1.00056: Calibration of the Shower Maximum Detector in the Barrel EMC at STAR Kara Farnsworth, Saskia Mioduszewski, Martin Codrington Because of a photon's lack of interaction with the quark-gluon plasma (QGP), the $\gamma $-jet process (in which a direct photon is produced back to back with a jet) is a good probe of the medium. However, background photons, like those from $\pi ^{0}$ decay must be factored in to the analysis. To distinguish between these direct and decay photons, a well calibrated detector is needed. The Barrel Shower Maximum Detector (BSMD) in the Barrel Electromagnetic Calorimeter (BEMC) at STAR has high resolution, but has not been calibrated well enough to discriminate between these two events. A pedestal subtraction was performed on the raw ADC vs. strip ID data from a Au+Au 200 GeV run. Each strip in both $\varphi $ (pseudorapidity) and $\eta $ (azimuth) was then assigned a status identification number, each corresponding to a hot, cold, dead, or good channel, for quality assurance. By finding the gains for each strip and normalizing them, calibration constants were obtained which can be applied to future runs. This accomplished a relative calibration of the BSMD. [Preview Abstract] |
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E1.00057: Improved Biomolecular Thin-Film Sensor based on Plasmon Waveguide Resonance Courtney Byard, Mustafa Aslan, Sergio Mendes The design, fabrication, and characterization of a plasmon waveguide resonance (PWR) sensor are presented. Glass substrates are coated with a 35 nm gold film using electron beam evaporation, and then covered with a 143 nm aluminum oxide waveguide using an atomic layer deposition process, creating a smooth, highly transparent dielectric film. When probed in the Kretschmann configuration, the structure allows for an efficient conversion of an incident optical beam into a surface wave, which is mainly confined in the dielectric layer and exhibits a deep and narrow angular resonance. The performance (reflectance vs. incidence angle in TE polarization) is modeled using a transfer-matrix approach implemented into a Mathematica code. Our simulations and experimental data are compared with that of surface plasmon resonance (SPR) sensor using the same criteria. We show that the resolution of PWR is approximately ten times better than SPR, opening opportunities for more sensitive studies in various applications including research in protein interactions, pharmaceutical drug development, and food analysis. [Preview Abstract] |
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E1.00058: Seasonal Variations of the Atmospheric Muon Flux in IceCube Dominick Rocco, Rasha Abbasi, Juan Carlos D\'Iaz V\'elez, Paolo Desiati The IceCube Observatory is a km$^3$ neutrino telescope under construction in the deep ice at the Geographic South Pole. Once fully deployed, it will consist of 4800 optical sensors tethered to 80 vertical strings to detect Cherenkov radiation from charged leptons. The data that IceCube is currently collecting is mostly triggered by muon bundles from air showers produced by the interaction of cosmic rays in the Earth's atmosphere. Muon production rate is sensitive to the atmospheric density profile, which is affected by the seasonal variations of temperature and pressure throughout the year. These variations, consequently induce a yearly modulation in the muon rate of about 20\%, as well as varying sensitively with temperature over shorter spans of a few days. The data collected by IceCube was analyzed and a strong day-to-day correlation with the measured temperature across the antarctic atmosphere was observed, and the corresponding temperature coefficient $\alpha_T = \left( {T\over N_{\mu}}\right) \cdot \left( {dN_{\mu}\over dT}\right) = 0.8908\pm 0.0092$. [Preview Abstract] |
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E1.00059: Simulating Background Radiation to Establish NuSTAR Detection Limits Sedona Price The NuSTAR (Nuclear Spectroscopic Telescope Array) project will launch a telescope array into orbit that will image X-rays of energies from 5 keV to 80 keV. To determine if the instrument meets the required sensitivity, we need to establish the lower bound on the flux into the detectors necessary to observe an object. To establish the minimum acceptable flux, analysis must be performed on a model of the background radiation. A model of the detector was made, accounting for the detector dimensions and telescope optics and data from prospective satellite orbits. Monte Carlo methods were employed to generate random background radiation events weighted according to the aperture and energy spectra data and the detector model, forming the background radiation simulation. The point spread function (PSF) for the NuSTAR telescope was used to model what would be detected from a point source. The model data was combined and the signal to noise ratio was inspected with variations in the sources modelled to establish the detection lower bound. The background simulation can be redone as the apparatus design changes, allowing for further analysis against source models. [Preview Abstract] |
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E1.00060: Testing and classification of various silicon detectors Edward Wunder In order to truly understand the techniques used in nuclear physics experiments and radiation detection, it becomes necessary to explore the basic interactions between the energy quanta and the detector itself, the way in which the detector signals and captures this energy, the methods of electronic signal processing, and, finally, the analysis of the data recorded during the testing. In my research, I explored three different types of silicon detectors, focusing on the most often used categories for classification and the tests used to get the results. [Preview Abstract] |
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E1.00061: Modeling Inflation with CMB and 21 cm Anisotropy Measurements Justin Feng, Asantha Cooray The Cosmic Microwave Background is now a well-known probe of the early Universe. We study a way to further improve our understanding of inflation by combining CMB data with anisotropy measurements of the 21 cm background at high redshifts. It has been suggested previously that the mapping of the 21 cm line can be used to significantly improve the constraints on the inflationary slow roll parameters, and consequently the allowed models for inflation. We use a Monte Carlo reconstruction code to study the relationship between the cosmological parameters as calculated at the 21 cm scale and the CMB scale. We also study the effects of combining the uncertainties in the measurements of the scalar spectral index from the 21 cm line with the current and expected CMB measurements in WMAP and Planck, respectively, on the tensor to scalar ratio. [Preview Abstract] |
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E1.00062: Decontaminating the Cosmological 21cm Background Paul Gebhart, Asantha Cooray This experiment is to determine what results can be expected for the 21cm line experiments planned for the radio telescopes Square Kilometre Array and Low Frequency Array. A simulation of the cosmological signal in the relevant frequency range, about 50 to 200 MHz, was constructed from simulated data of a 21cm line model, interpolated data of Milky Way synchrotron, a simulated map of extragalactic radio sources, and Gaussian noise based on the parameters of SKA and LOFAR. We are attempting to determine how to separate the 21cm signal from the foreground signal and whether the residual after removal is too noisy to degrade the matter power spectrum of the cosmological 21cm line signal. [Preview Abstract] |
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E1.00063: ABSTRACT WITHDRAWN |
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E1.00064: Observation of a Low-Lying Neutron Unbound State in 25F A.R. Smith, M. Kasperczyk, N. Frank, T. Baumann, D. Bazin, B.A. Brown, J. Brown, P.A. DeYoung, J.E. Finck, A. Gade, J. Hinnefeld, R. Howes, J.-L. Lecouey, B. Luther, W.A. Peters, H. Scheit, A. Schiller, M. Thoennessen, J. Tostevin A low energy neutron unbound state of $^{25}$F has been observed. The $^{25}$F isotopes were produced by one-proton removal from an 86 MeV/u $^{26}$Ne beam on a Beryllium target at the fast-fragmentation radioactive beam facility of the National Superconducting Cyclotron Laboratory at Michigan State University. The subsequent decay of the $^{25}$F isotopes resulted in $^{24}$F and neutrons that were detected in coincidence. The properties of the charged particles and neutrons were used to reconstruct a decay energy spectrum for $^{25}$F, which was compared to simulations. The simulations include a stripping reaction model, decay energy line-shapes, and, detector resolutions and acceptances. Results and simulation details will be discussed. [Preview Abstract] |
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E1.00065: The Interaction of Nuclei in the Gravitational Fields of Mini Black Holes Lauren Greenspan The goal of this research was to find solutions to the Schrodinger equation that describe particle scattering around mini black holes (on the order of a fermi). Black holes of this kind could have formed in density irregularities in primordial space just after the big bang and can answer cosmological questions as well as provide a setting for research in quantum-gravity. Black holes go along with the theory of general relativity, but since mini black holes can be comparable in size to nucleons, the project also considers the limit at which the black hole must obey Quantum Mechanical law. A large emphasis was placed on the choice of a coordinate system and its implications on general relativity and the curvature of space-time. We derived the potentials for the black hole and used them to calculate the absorption cross-section in the non-relativistic limit. As an additional exercise, we calculated the possible bound states of a particle with the black hole and the amount of mass it could gain based on the expected cross-section. [Preview Abstract] |
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E1.00066: TESTS OF PHYSICAL LAWS |
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E1.00067: An Experimental Overview of Ultra-Cold Neutron Production in Solid Oxygen through Magnetic Interactions Daniel Salvat, Chen-Yu Liu, Christopher Lavelle, Patrick McChesney, Gregory Manus, Yu Feng, Yunchang Shin, Albert Young, Guilhem Ribeill, Adam Holley, Chris Morris, Andy Saunders, Mark Makela We present an experiment to investigate UCN production in solid oxygen under applied magnetic field, and discuss results from data collected at Los Alamos Neutron Science Center in 2008. The instrument is designed to study UCN production as a function of temperature, source volume, and possesses unique magnetic field capabilities up to 5.5 Tesla. We measure incident neutron energy dependence using the beam-line's cold-neutron choppers. The data suggest a comparable UCN production rate between oxygen and deuterium, and surprising phase dependent production in oxygen. [Preview Abstract] |
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E1.00068: The Search for Dark Matter: Detection Rates of Axion-like Particles as a Function of Mass in Ge and NaI Detectors Eric Gutman Theoretical derivations of the pseudoscalar and scalar dark matter (DM) particle counting rates by detectors with Ge and NaI targets have been put forth by the DAMA research team and other such groups, with those of the DAMA team being recently disputed. This research impartially performs a computation of counting rate versus DM particle mass using each of these theories, presents the final quantitative results, and analyzes their significance and mutual compatibility. A background of the physical context behind the derivations is given first, and an discussion of their potential impacts, should they be found correct, on the theoretical and experimental exploration of dark matter concludes. [Preview Abstract] |
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E1.00069: Nonstationary Casimir Effect: Quantum Emission by Oscillating Mirror Imbi Tehver, Vladimir Hizhnyakov, Helle Kaasik Recently many authors have become interested in the nonstationary Casimir effect - quantum emission due to the change of border conditions in time. The case of a cavity has been discussed in detail. We study an oscillating mirror. The oscillations perturb the zero-point state, causing a weak emission, which strongly increases if the maximum velocity approaches c. The spectrum of the emission has a peak at half oscillation frequency, which diverges logarithmically in the cone with the angle Pi/3. Periodical changes of the zero-point state may result from the oscillations of the refractive index of a medium exposed in the laser field [1]. If the maximum velocity of the oscillations of the optical length approaches 2.94 c, then a strong enhancement of the emission takes place [2]. This condition corresponds to the resonance between the oscillations of the optical length and the wavelength of the modes, which emit photons. Modern laser facilities allow one to achieve the enhancement condition. 1. V. Hizhnyakov, Quantum Optics, 4, 277 (1992). 2. V. Hizhnyakov, H. Kaasik. J. Phys. Conf. Series, 21, 155 (2005). [Preview Abstract] |
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E1.00070: A Null Shell in 2+1 Gravity Nelson Zamorano, Pe\~na Leda Using the generalized Kerr-Schild method we have been able to extend the charged BTZ solution including a null field travelling along the horizon. The exterior solution remains unaltered up to a renormalization of the charge. The geodesic structure is displayed and analized at the horizon. The equivalent solution for the 3+1 case and higher dimensions are discussed. Decreasing the dimensionality of the space turns a Dirac delta function to a step function sitting at the horizon. [Preview Abstract] |
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E1.00071: An Extension of the Special Theory of Relativity J. Chakrabarty, B.C. Saha We report an extension of the Einstein's Special Theory of Relativity to handle the special cases in which the speed of the moving particle is comparable to or even exceeding the speed of light. Employing an apparent speed of light relative to the moving observer we propose an empirical relations that works pretty well. Details of our results will be presented at the conference. Supported by National Science Foundation, CREST Program. [Preview Abstract] |
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E1.00072: A Quantized Metric As an Alternative to Dark Matter David Maker There are numerous observations implying the need for dark matter (WMAP, SDSS). The first direct evidence for dark matter was the observation that individual galaxy velocities inside clusters cannot be reproduced by the distributions of visible galactic matter alone (Zwicky 1933). The most compelling evidence for the existence of dark matter comes from galaxy halo velocity curves that are too high to be accounted for by the visible matter alone. Large scale structure arguments along with WMAP results require the dark matter candidate to be cold and weakly interacting. SUSY offers a natural candidate in the form of the neutralino with R parity conservation providing the mechanism for its stability (1, O'Farrill 2004). However SUSY does not provide a mechanism for dark energy. In order to deal with the problem of an accelerating expansion in the universe one must make other sets of assumptions. Also, recent observations show a quantization in the red shift, a quantization in spiral galaxy velocity curves and quantized small galaxy masses that are well outside of what any dark matter algorithms can simulate. This paper provides an alternative explanation of these well known effects and also explains the observed quantization by using a new generally covariant Dirac equation (2, Maker, 1998) with a quantized background metric. The three ambient metric contributions in this new Dirac equation also constitute the 3 free space leptons. [Preview Abstract] |
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E1.00073: The Calculus of Relativistic Temporal Geometry Alexander Mayer Richard Feynman's unpublished 1965 gedanken experiment, discussed on pages 60–62 of A. F. Mayer, On the Geometry of Time in Physics and Cosmology (April 2009), demonstrates that the principles of relativity destroy both Newton's concept of absolute time and the concept of a Newtonian gravitational equipotential surface. According to logic arising from experience, it has long been falsely assumed that no energy cost is incurred for translation over an ideally frictionless level surface in the presence of a vertical acceleration. However, that the speed of light is a limiting velocity implies that while two distinct points on such a surface can be considered to be at the same potential relative to a third point that is not on that surface, a particle translated between two such points must incur energy transfer to the accelerating field. Typically, this manifests as a redshift of electromagnetic radiation as demonstrated by ``Feynman's rocket.'' Accurate calculation of this relativistic transverse gravitational redshift (TGR) for observable phenomena in a real-world astrophysical gravitational field requires the calculus of relativistic temporal geometry. Calculations using this technique accurately predict the following empirically observed but heretofore unexplained natural phenomena: the center-to-limb variation of solar wavelength ($\sim$1 km/ s), the K-effect for massive main sequence stars ($\sim$2-3 km/s), and the excess redshift of white dwarf stars ($\sim$10-15 km/s). [Preview Abstract] |
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E1.00074: Hubble Refshift due to the Global Non-Holonomity of Space Dmitri Rabounski In General Relativity, the change of the energy of a freely moving photon should be the solution to the scalar equation of the isotropic geodesic equations, which manifests the work produced on the photon being moved along the path. I solved the equation in terms of physical observables (Zelmanov, Phys. Doklady, 1956, v.1, 227), and in the large scale approximation, i.e. with gravitation and deformation neglected in the space, while supposing the isotropic space to be globally non-holonomic (the time lines are non-orthogonal to the spatial section, a condition manifested by the rotation of the space). The solution is E=E$_{0}$exp(-H$^{2}$AT/c), where H is the angular velocity of the space (it meets the Hubble constant H$_{0}$=c/A=2.3x10$^{-18}$s$^{-1})$, A is the radius of the Universe, T=L/c is the time of the photon's travel. So a photon loses energy with distance due to the work against the field of the space non-holonomity. According to the solution, the redshift should be z=exp(H$_{0}$L/c)-1$\approx $H$_{0}$L/c. This solution explains both the redshift z=H$_{0}$L/c observed at small distances and the non-linearity of the empirical Hubble law due to the exponent (at large L). The ultimate redshift, according to the theory, should be z=exp($\pi)$-1=22.14. [Preview Abstract] |
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E1.00075: Theoretical Grounds to the Table of the Elements of Anti-Substance Albert Khazan If equilateral hyperbolas were created with X$<$0, Y$<$0 (K$>$0), they build the second branches in the 3rd quadrant. In contrast to hyperbolas in mathematics, the conditions Y$\le $1 and K$\le $X don't give congruency (this is because the different scales and dimensions of the axes). This inadequacy vanishes if using the coefficient M (20.2895). With it the properties of the hyperbolas in the 1st quadrant are verified in the 3rd quadrant. The 2nd and 4th quadrants show the same on the hyperbolas. Reducing the axes to the joint scale doesn't lead to congruency in full. The ordinate (the rate of transformation of matter) is negative in the 3rd and 4th quadrant that is unseen in nature. Thus, we consider the 1st and 2nd quadrants (there is K$>$0 N K$<$0). In the quadrants, the curves meet each other around the ordinate. Thus, the Hyperbolic Law is true in the 2nd quadrant as well (it is ``inhabited'' by ``negative matter,'' i.e. anti-matter consisting antiparticles). This allowed me to create the Periodic Table of the elements of anti-matter (see Progr. Phys., 2007, v.1, 38; v.2, 83; v.2, 104; 2008, v.3, 56). [Preview Abstract] |
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E1.00076: Calculating Particle-Mass Hierarchy Terrence McGrath We describe a new approach to our fundamental understanding of particle mass. Starting with a spherical potential well (Bohm) as the description for a nucleus we show that six independent sets of electromagnetic waves interacting with the field generate fundamental symmetries that can be related to the organization of mass structure. Resonances between the nucleus and whole integer four-wave node intersections within the field surrounding the well generates closed paths of energy transfer whose scale can be defined using high-density lattice circle solutions using recursive geometric techniques. These energy loops are shown to provide real world solutions for calculating the relative masses of electrons, protons, neutrons and quarks, each to five places accuracy. The proposed loop structure and mechanics of energy transfer also provide a conceptual foundation for the particle mechanics for charge, the electric and magnetic fields, and quark confinement. Interestingly these quantum loops also provide the missing confinement component of Wilson Loops introduced in 1974. [Preview Abstract] |
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E1.00077: On a New Analysis of the Problem of the Planck Constant Temur Kalanov A new analysis of the problem of Planck constant is proposed. The analysis is based on the formal logic. It is shown [1] that well-known formula $E_n \;\equiv \;h\nu _n $ (where $E_n $, $h$, and $\nu _n $ are energy, Planck constant (i.e. quantum of action), and the frequency of the periodic process of mutual transformation of the internal and external motions, respectively) is correct if $\nu _n $ is the frequency of oscillation of Planck constant. In other words, multiplication of the quantities $h$ and $\nu _n $ is permitted by logic law of identity if $h$ is an oscillating quantity. Ref.: [1] T.Z. Kalanov, ``The correct theoretical analysis of the foundations of classical thermodynamics,'' Bull. of Pure and Applied Sciences, Vol. 26D, No 2 (2007), pp. 109-118. [Preview Abstract] |
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E1.00078: An Introduction to Neutrosophic Probability Applied in Quantum Physics Florentin Smarandache In this paper we generalizes the \textit{classical probability} and \textit{imprecise probability} to the notion of \textbf{neutrosophic probability} in order to be able to model Heisenberg's Uncertainty Principle of a particle's behavior, Schr\"{o}dinger's Cat Theory, and the state of bosons which do not obey Pauli's Exclusion Principle (in quantum physics). Neutrosophic probability is close related to neutrosophic logic and neutrosophic set, and etymologically derived from neutrosophy. [Preview Abstract] |
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E1.00079: PHYSICS EDUCATION |
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E1.00080: Design and Implementation of a Muon Lifetime Experiment for an Undergraduate Laboratory Course Jonathan Powers, Matt Bowles We have developed a simplified muon lifetime experiment, following an established design, for use in an instructional laboratory. The experiment utilizes a pot of liquid scintillator, photomultiplier tube, discriminator, time-to-amplitude converter, and PC mounted with a multichannel analyzer. Cosmic muons that decay in the scintillator produce pulse pairs, and measuring the time between pulses provides a muon decay time measurement. The lifetime is obtained by fitting the distribution of multiple measurements. An analysis of a one-week trial using the bootstrap method yielded a lifetime of 2.10 $\mu$s with a standard deviation of 0.115 $\mu$s. These results agree with the accepted lifetime of 2.19 $\mu$s. Students conducted the experiment for the first time this semester, following guidelines we developed. Our achievements, detailed in the poster, are based on the ability of students to set up the experiment, analyze the data, and the accuracy of the data obtained. [Preview Abstract] |
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E1.00081: The Harmony of Physics, Mathematics, and Music: A discovery in mathematical music theory is found to apply in physics Richard Krantz, Jack Douthett Although it is common practice to borrow tools from mathematics to apply to physics or music, it is unusual to use tools developed in music theory to mathematically describe physical phenomena. So called ``Maximally Even Set'' theory fits this unusual case. In this poster, we summarize, by example, the theory of Maximally Even (ME) sets and show how this formalism leads to the distribution of black and white keys on the piano keyboard. We then show how ME sets lead to a generalization of the well-known ``Cycle-of-Fifths'' in music theory. Subsequently, we describe ordering in one-dimensional spin-1/2 anti-ferromagnets using ME sets showing that this description leads to a fractal ``Devil's Staircase'' magnetic phase diagram. Finally, we examine an extension of ME sets, ``Iterated Maximally Even Sets'' that describes chord structure in music. [Preview Abstract] |
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E1.00082: Infusing Renewable Energy Concepts into aTeacher Prep Graduate Course Ruwang Sung Energy and renewable energy concepts have been systematically incorporated into an on-line graduate course, ``Energy for Today and Tomorrow'', for in-service science teachers. Students learn fundamental physics principles and laws through study of various forms of energy, energy conversion, conservation of energy and renewable energy basics. The effectiveness of this approach will be discussed, as well as the course content materials, delivery method, and student research papers which relate to their experience of promoting renewable energy in K-12 education and the community. [Preview Abstract] |
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E1.00083: GRAVITATION |
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E1.00084: Implications of Planck Scale Statistics Shantilal Goradia Numerous analyses suggest that if modified Newtonian dynamics known as MOND turns out to be correct, the need for Dark Matter is obviated. It is also likely that it impacts the issue of Dark Energy to explain the accelerating expansion of the universe. In order to unify GR with QM we take a completely different approach. We use Planck scale statistics (PST) to describe all distances in [1]. We take similar approach to modify Newtonian gravity in [2] to arrive at what may be called probabilistic Newtonian dynamics (PROND). PROND links strong coupling with gravity, as does MOND. It does so naturally without having to renormalize. PST links fine structure constant with the age of the universe. If PST can link the size of the universe to fine structure constant, PST may also accomplish what MOND does on the issue of Dark Matter. At least, we show such additional abilities of PST to justify its use to probe the unity of everything. [1] http://arXiv.org/pdf/physics/0210040v3, [2] http://arXiv.org/pdf/physics/0210040v4. [Preview Abstract] |
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E1.00085: Black Holes and other exotica at the Large Hadron Collider Arunava Roy, Marco Cavaglia If the fundamental scale of gravity is of the order of 1 TeV, black holes might be produced at the Large Hadron Collider. We present simulations of black holes and other exotic predictions of physics beyond the Standard Model - supersymmetry and string theory. Black hole events are simulated using the CATFISH Monte Carlo generator, simulations of string resonances use PYTHIA and supersymmetric simulations use a combination of ISAJET and PYTHIA. Our analysis shows that black holes can be discriminated from supersymmetry and string resonances. Isolated leptons with high transverse momentum can be used to distinguish black holes and supersymmetry. Z bosons and photons with high transverse momentum allow the discrimination of black holes and string resonances. The analysis of visible and missing energy /momenta, event-shape variables and multilepton events complement these techniques. [Preview Abstract] |
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E1.00086: Test Equal Bending by Gravity for Space and Time Douglas Sweetser For the simplest problem of gravity - a static, non-rotating, spherically symmetric source - the solution for spacetime bending around the Sun should be evenly split between time and space. That is true to first order in M/R, and confirmed by experiment. At second order, general relativity predicts different amounts of contribution from time and space without a physical justification. I show an exponential metric is consistent with light bending to first order, measurably different at second order. All terms to all orders show equal contributions from space and time. \\ \\Beautiful minimalism is Nature's way. [Preview Abstract] |
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E1.00087: ABSTRACT WITHDRAWN |
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E1.00088: ABSTRACT WITHDRAWN |
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E1.00089: A numerical way around the propagation-delay equations in GPS Argenis Da Silva, Jonathan Downling We present a numerical self-consistent way to account for relativistic effects in GPS. Our approach has two main advantages respect to the use of the traditional method of flat space-time propagation-delay equations plus relativistic corrections. At First, any improvement of our knowledge about the spacetime geometry will not produce further changes in the algorithm. And second, all the relativistic effects are fully and clearly accounted for. On the other hand, this numerical approach could be used as a seed to improve a method proposed in the literature based in the world function. To illustrate the ideas behind our method, we use the Schwarzschild geometry as a testbed. [Preview Abstract] |
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E1.00090: Change and Hope in Physics Shantilal Goradia Physics = Ideas + Analyses. Newton reconciled Kepler's laws, Einstein's GR reconciled action at a distance. Our Planck Scale Statistics (see v3 and v4 of [1]) is a change that reconciles gravity with quantum physics simply. It does what a change should do and I will answer your questions again. It completes TOE, so what? There should not be any fear about disappearance of challenges. It will create other challenges to occupy creative physicists meaningfully. Physicists score highest on GRE score with the exception of mechanical engineers. They will come up with ideas applicable to other sectors like energy and economy. Newton, also a gold mine executive, introduced annuity for life, an insurance feature of social security. Here, I try one bold suggestion to illustrate the point. Putting 10{\%} tax on new housing permits would raise the price of each house in the USA by an average of 2 x 10$^{4 }$dollars generating a wealth of 2x10$^{12}$ dollars for existing 10$^{8}$ houses, encouraging people to stick to their houses, inviting investors to grab existing houses, discouraging new construction which goes against the sale of existing houses, and injecting two trillion dollars in the economy without creating a deficit budget. The hope is that this change would challenge other high GRE scorers to come up with additional ideas. It is imaginative minds that solve problems, not subjective knowledge. [1] http://www.arXiv.org/pdf/physics/0210040. [Preview Abstract] |
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E1.00091: GENERAL |
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E1.00092: ABSTRACT WITHDRAWN |
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E1.00093: ABSTRACT WITHDRAWN |
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E1.00094: MicroBooNE: A Liquid Argon Time Projection Chamber in the Booster Neutrino Beam Joshua Spitz MicroBooNE, a next generation Liquid Argon Time Projection Chamber (LArTPC) based experiment, will begin taking data in the Booster Neutrino Beam at Fermilab in 2011. The experiment's goals, including cross section measurements relevant for future long-baseline neutrino oscillation searches, understanding the MiniBooNE low-energy excess, and research and design towards a kiloton-scale LArTPC are presented. [Preview Abstract] |
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E1.00095: Parity Violation DIS at High Energy Bowen Xiao, Jianwei Qiu, Feng Yuan Geometrical scaling is a remarkable phenomena found in HERA. In this paper, we study the small-x behavior for the parity violating deep inelastic scattering, in particular considering the neutral current and charge current contributions, through photon, $Z$ and $W$ bosons exchanges by using their wave functions. We find geometrical scaling not only in the case of neutral current exchange but also in the charged current case. Moreover, we show that the parity violating structure functions $F_3$ vanish at small-x if the valence quark contribution is negligible. In addition, the polarized structure functions are also computed in this framework. [Preview Abstract] |
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E1.00096: BEAM PHYSICS |
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E1.00097: ABSTRACT WITHDRAWN |
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E1.00098: Electron Impact Excitation Collisions and Atomic Models for RF Breakdown Simulations Sudhakar Mahalingam, Seth Veitzer, Peter Stoltz Neutrino factory experiments will produce high-intensity beams through the in-flight decay of muons. Such high-intensity muon beams can be produced effectively using cavities that employ high field gradients for acceleration. However, such cavities are limited by breakdown phenomena. Recent muon cooling experiments and numerical simulations of RF breakdown models provide insights into the possible triggering mechanisms responsible for breakdown. We are currently improving our numerical RF breakdown models by including detailed atomic and plasma processes such as electron impact excitation, plasma radiation, and electron impact X-ray emission from cavity surfaces. We describe here the new physics algorithms that are being implemented as a numerical library and are being interfaced to a number of particle-in-cell plasma simulation codes. The required atomic and surface interactions data are obtained from Evaluated Electron Data Library (EEDL) available from IAEA Nuclear Data Services. Also we describe the tracking of different excited levels of copper atoms in the 3-D PIC plasma simulation code VORPAL. [Preview Abstract] |
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E1.00099: New Diffusion Analysis Tools for Beam Beam Simulations Vahid Ranjbar, Andrey Sobol, Tanaji Sen, Hyung Jin Kim A new set of tools for BBSIM has recently been developed to analyze the nature of the diffusion in multi-particle simulations. The diffusion subroutines are currently used to accelerate beam lifetime calculations by estimating the diffusion coefficient at various actions and integrating the diffusion equation. However it is possible that there may be regimes where anomalous diffusion dominates and normal diffusion estimates are incorrect. The tools we have developed estimate the deviation from normal diffusion and can fit the coefficients of a jump diffusion model in the event that this type of diffusion dominates. [Preview Abstract] |
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E1.00100: Fringe Field Properties in Magnets with Multipole or Mid-plane Symmetry George Bell, Dan Abell The design of an accelerator with a large energy acceptance requires careful consideration of fringe-field effects. This applies particularly to the design of fixed-field alternating gradient (FFAG) accelerators. We consider magnets in straight and curved geometries, and with multipole or mid-plane symmetries. The longitudinal magnet profiles we consider include a simple hyperbolic tangent and a more realistic six-parameter Enge function. We show that when the fields are modeled using power series expansions in a transverse parameter, the domain of convergence is determined by the fringe-field decay length. We also demonstrate the use of these models in the tracking code PTC. [Preview Abstract] |
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E1.00101: COMPUTATIONAL PHYSICS |
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E1.00102: Computing Beyond the Church-Turing Limit Robert Jones Dershowitz and Gurevich claim to have proven the Church-Turing theorem starting from a set of 4 reasonable postulates. (Bulletin of Symbolic Logic, vol. 14, num. 3, Sept. 2008, pg. 299) But their postulate II assumes fixed vocabulary. Humans, however, change their vocabulary words (and concepts) over time. My Asa H artificial intelligence also changes its vocabulary. (Trans. of the Kansas Acad. of Sci., vol. 109, no. 3/4, pg 159, 2006, www.bioone.org/archive/0022- 8443/109/3/pdf/i0022-8443-109-3-159.pdf) Their postulate I excludes nondeterministic transitions between states. I don't know how often humans flip a coin but my Asa H does employ random transitions under certain circumstances. Perhaps humans and Asa H go beyond the Church-Turing limit. (Trans. Kansas Acad. of Sci., 108, 3/4, pg. 169, 2005) [Preview Abstract] |
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E1.00103: ABSTRACT WITHDRAWN |
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E1.00104: ACCELERATORS AND STORAGE RINGS |
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E1.00105: Dual-energy Operations at LANSCE for Proton Induced Nuclear Cross Section Measurements M.S. Gulley, C. Pillai, L.J. Bitteker, A. Seifter, F.M. Nortier, D.M. Smith, H. Bach, A.J. Couture, R.E. Gritzo, J.L. Ullmann, F.O. Valdez, S.A. Wender The WNR facility at LANSCE is preparing for a set of proton induced cross section measurements in support of the LANL Isotope Production Program. To determine the best way to produce particular isotopes, it is necessary to measure the production rate's energy dependence. The first measurements will use a 197-MeV proton beam, which prompted recovery of the facility's ability to transport multiple energy proton beams simultaneously to different experimental areas to ensure that an 800-MeV beam is available for Proton Radiography or Ultra-Cold Neutron experiments while a sample is irradiated with a lower energy beam for the cross section measurements. The ability to change the beam energy pulse-to-pulse was built into the original accelerator controls, but the multiple energy controls were unused for over a decade and the system was re-commissioned for this effort. These experiments form part of an effort to establish a capability for the measurement of cross sections in the 197 to 800 MeV energy range. The experiments are expected to provide the needed data for activities that may develop into a unique isotope production capability to compliment the existing 100-MeV IPF facility. [Preview Abstract] |
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E1.00106: ACCELERATOR SYSTEMS |
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E1.00107: Realistic Models for RF Cavities Dan Abell, Ilya Pogorelov, Peter Stoltz We present realistic models, including fringes, for several standing-wave modes in rf cavities. These models include a simple accelerating mode and a TM-110 (crab) mode. They are useful for the accurate computation of transfer maps% \footnote{D.T. Abell, ``Numerical computation of high-order transfer maps for rf cavities'', \emph{Phys. Rev. ST Accel. Beams} \textbf{9}, 052001, (2006).} as well as for constructing model fields that can be used for testing and comparing a variety of rf cavity codes. [Preview Abstract] |
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